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Prevalence and associated factors of hypertension in primary school children in mbankomo subdivision in the mefou and akono division, centre region


par Edmond Ngong Chiabi
Faculty of medecine and biomedical sciences - University of Yaounde I - Medicinae Doctorae (MD) 2017
  

Disponible en mode multipage

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REPUBLIQUE DU CAMEROUN

Paix - Travail - Patrie

------------------------

UNIVERSITE DE YAOUNDE I

-----------------------

FACULTE DE MEDECINE ET DES

SCIENCES BIOMEDICALES

-------------------------

Prevalence and associated factorsofhypertension in primary school children in Mbankomo subdivision in the Mefou and Akono division, Centre Region

Thesis presented in partial fulfilment of requirements for the Award of the Medicinae Doctorae (MD) degree

By:

CHIABI Edmond NGONG

Matricule: 11M211

SupervisorCo-Supervisors

Pr OBAMA Marie Thérèse Pr CHELO David

Professor of Pediatrics Associate Professor of Pediatrics-Cardiology

Pr MAH Evelyn MUNGYEH

Associate Professor of Pediatrics

TABLE OF CONTENT

PREFACE ii

DEDICATION iii

ACKNOWLEDGEMENT iv

LIST OF ADMINISTRATIVE AND ACADEMIC STAFF OF FACULTY OF MEDICINE AND BIOMEDICAL SCIENCES (FMBS) YAOUNDE FOR THE 2017/2018 ACADEMIC YEAR v

THE PHYSICIAN'S OATH xvi

LIST OF TABLES xvii

LIST OF FIGURES xviii

LIST OF ABBREVIATIONS/ACRONYMS/SYMBOLS xix

ABSTRACT xx

RESUME xxii

CHAPTER I: INTRODUCTION 1

CHAPTER II: JUSTIFICATION OF STUDY 4

CHAPTER III: RESEARCH QUESTION 6

CHAPTER IV: RESEARCH HYPOTHESIS 8

CHAPTER V: OBJECTIVES 10

CHAPTER VI: LITERATURE REVIEW 2

CHAPTER VII: MATERIALS AND METHODS 40

CHAPTER VIII: RESULTS 57

CHAPTER IX: DISCUSSION 77

CHAPTER X: CONCLUSION AND RECOMMENDATIONS 84

CHAPTER XI: REFERENCES 87

CHAPTER XII: APPENDIX xxiv

PREFACE

DEDICATION

I dedicate this work to,

My father CHIABI Andreas TEHJIand

My mother CHIABIEmma Rilindis nee NCHAM

ACKNOWLEDGEMENT

I am immensely grateful to the ALMIGHTY GOD for his gift of life, wisdom, strength, good health and continuous blessings throughout my medical studies.

My sincere thanks to;

· My Supervisor Prof OBAMAMarie Theresefor her insightful comments, encouragement, continuous guidance, patience, motivation and immense knowledge in the supervision of this work.

· My Co-supervisor Prof CHELO David for his tremendous efforts, comments and encouragement in the co-supervision of this work.

· My Co-supervisor Prof MAH Evelyn MUNGYEH for her insightful comments, patience and guidance throughout this research period. I am very grateful, thank you so much for your guidance throughout these years.

· All the participants and legal tutors in my survey, who willingly shared their precious time throughout the study.

· All the lecturers of the Faculty of Medicine and Biomedical Sciences (FMBS) for grooming me throughout the seven years of medical school.

· My parents for all the sacrifices that they have made on my behalf. Your prayer for me was what sustained me this far.

· My brothers: CHIABI Roland, CHIABI Valery and CHIABI Leslie; and the rest of my family for the support and the love.

· All my friends, most especially MOUGOUE MANIGOUE Ange Merici, BANE Jodie, NGO NKOUM Marie Ange, DANG ODI Lionel, BALOMOG Audrey, TCHEBEGNA Partick Yvanand YOMKIL BAYE Jean Jacquefor the love, the friendship, and the support we have shared throughout these years.

· The Inspector of Basic Education, and the director of the district hospital of Mbankomo as well as the Delegate of Basic Education of Ngoumou for your support and encouragement.

· MrTCHUISSEU Fréderic for the statistical analysis.

· All those who contributed in the elaboration of this work.

LIST OF ADMINISTRATIVE AND ACADEMIC STAFF OF FACULTY OF MEDICINE AND BIOMEDICAL SCIENCES (FMBS) YAOUNDE FOR THE 2017/2018 ACADEMIC YEAR

S/N

1. ADMINISTRATIVE PERSONNEL

1.

Pr ZE MINKANDE Jacqueline

Dean 

2.

Pr NTSAMA ESSOMBA Claudine Mireille

Vice- Dean in charge of programs and academic activities follow-up

3.

Pr Gloria Enow ASHUNTANTANG

Vice-Dean in charge of School, Statistics and Students follow-up

4.

Pr KAMGNO Joseph

Vice- Dean in charge of Research and Cooperation

5.

Mr MEKA Gaston

Director of Administrative and Financial affairs

6.

Pr BENGONDO MESSANGA Charles

Director of Academic, School and Research affairs

7.

Pr MOUAFO TAMBO Faustin

General Coordinator of Specialisation Cycle:

8.

Mr. ADAMOU

Director of Financial Service

9.

Dr SAMBA Odette NGANO ép. TCHOUAWOU

Director of General Administration and Personnel Service

10.

Mme ASSAKO Anne DOOBA

Chief of Service; Certificates

11.

Dr NSEME Eric

Chief of Service; School and Statistics

12.

M. MPACKO NGOSSO Charles Romuald

Chief of Service; Materials and Maintenance

13.

Mme FROUISSOU née MAME Marie-Claire

Interim Chief of the Library

14.

Mme ANDJISSILE ENAM Suzel Chanel

Accounting Matters

 

2. COORDINATORS AND HEAD OF DEPARTMENTS

1.

Pr BENGONDO MESSANGA Charles

Coordinator of Dentistry Department

2.

Pr NTSAMA ESSOMBA Claudine

Coordinator of Pharmacy Department

3.

Pr ONGOLO ZOGO Pierre

Coordinator of Internist Department

4.

Pr ESSAME OYONO Jean Louis

Coordinator of Specialisation Cycle in Anatomy Pathology Department

5.

Pr ZE MINKANDE Jacqueline

Coordinator of Specialisation Cycle in Anaesthesiology and Reanimation Department

6.

Pr NGO NONGA Bernadette

Coordinator of Specialisation Cycle in General Surgery Department

7.

Pr MBU ENOW Robinson

Coordinator of Specialisation Cycle in Gynaecology and Obstetrics Department

8.

Pr NGANDEU Madeleine

Coordinator of Specialisation Cycle in Internal Medicine Department

9.

Pr CHIABI Andreas

Coordinator of Specialisation Cycle in Paediatrics Department

10.

Pr GONSU Hortense

Coordinator of Specialisation Cycle in Clinical Biology Department

11.

Pr NKO'O AMVENE Samuel

Coordinator of Specialisation Cycle in Radiology and Medical Imaging Department

12.

Pr TAKOUGANG Innocent

Coordinator of Specialisation Cycle in Public Health Department

 

HONORARY DIRECTORS OF CUSS

1.

Pr MONEKOSSO Gottlieb (1969-1978)

Internal Medicine/Neurology

2.

Pr EBEN MOUSSI Emmanuel (1978-1983)

Physiologic Science/Biochemistry; Pharmacology

3.

Pr NGU LIFANJI Jacob (1983-1985)

Internal Medicine/Nephrology

4.

Pr CARTERET Pierre (1985-1993)

Physiologic Sciences/Biochemistry; Physiology

 

HONORARY DEANS OF FMBS

1.

Pr SOSSO Maurice Aurélien (1993-1999)

Surgery and Specialties: General Surgery

2.

Pr NDUMBE Peter (1999-2006)

Haematology, Microbiology and Parasitology

3.

Pr TETANYE EKOE Bonaventure (2006-2012)

Paediatrics

4.

Pr EBANA MVOGO Côme (2012-2015)

Ophthalmology/ORL

 

3. TEACHING STAFF

 

DEPARTMENT OF SURGERY AND SPECIALTIES

 

A. Professors

1.

SOSSO Maurice Aurélien (CD)

General Surgery

2.

AFANE ELA Anatole

Anaesthesiology-Intensive care

3.

ANGWAFO III Fru

Surgery: Urology

4.

DJIENTCHEU Vincent de Paul

Surgery: Neurosurgery

5.

ESSOMBA Arthur

General Surgery

6.

NGOWE NGOWE Marcellin

General surgery

7.

ZE MINKANDE Jacqueline

Anaesthesiology- Intensive care

 

B. Associate Professors

1.

BEYIHA Gérard

Anaesthesiology- Intensive care

2.

ELOUNDOU NGAH J.

Surgery: Neurosurgery

3.

ESIENE Agnès

Anaesthesiology- Intensive care

4.

EYENGA Victor Claude

Surgery: Neurosurgery

5.

FARIKOU Ibrahima

Orthopaedic Surgery

6.

FOUDA Pierre

Surgery: Urology

7.

MOUAFO TAMBO Faustin

Paediatric Surgery

8.

NGO NONGA Bernadette

General Surgery

9.

ONDOBO ANDZE Gervais

Paediatric Surgery

10.

PISOH Christopher

General Surgery

 

C. Senior Lecturers

1.

AHANDA ASSIGA

General Surgery

2.

GUIFO Marc Leroy

General Surgery

3.

HANDY EONE Daniel

Orthopaedic Surgery

4.

OWONO ETOUNDI Paul

Anaesthesiology- Intensive care

5.

TSIAGADIGI Jean Gustave

Orthopaedic Surgery

 

D. Lecturers

1.

AMENGLE Albert Ludovic

Anaesthesiology- Intensive care

2.

BANG GUY Aristide

General surgery

3.

BENGONO BENGONO Roddy Stéphan

Anaesthesiology- Intensive care

4.

BWELE Georges

General surgery

5.

JEMEA Bonaventure

Anaesthesiology- Intensive care

6.

NGO YAMBEN Marie Ange

Orthopaedic Surgery

 

DEPARTMENT OF INTERNAL MEDICINE AND SPECIALTIES

 

A. Professors

1.

NJOYA OUDOU (CD)

Internal Medicine/Gastro-enterology

2.

AFANE ZE Emmanuel

Internal Medicine/Pulmonology

3.

BIWOLE SIDA Magloire

Internal Medicine/Hepato-Gastro-enterology

4.

KINGUE Samuel

Internal Medicine/Cardiology

5.

MBANYA Jean Claude

Internal Medicine/Endocrinology

6.

NDJITOYAP NDAM Elie Claude

Internal Medicine/Hepato-Gastro-enterology

7.

NDOM Paul

Internal Medicine/ Oncology

8.

NJAMNSHI Alfred K.

Internal Medicine/Neurology

9.

NOUEDOUI Christophe

Internal Medicine/ Endocrinology

10.

SINGWE Madeleine épse NGANDEU

Internal Medicine/Rhumatology

 

B. Associate Professors

1.

ANKOUANE ANDOULO

Internal Medicine/Hepato-Gastro-enterology.

2.

ASHUNTANTANG Gloria Enow

Internal Medicine/ Nephrology

3.

BISSEK Anne Cécile

Internal Medicine/Dermatology

4.

KAZE FOLEFACK François

Internal Medicine/Nephrology

5.

KUATE TEGUEU Calixte

Internal Medicine/Neurology

6.

MENANGA Alain Patrick

Internal Medicine/Cardiology

7.

NGOUNOU NOUBISSIE Marie ép. DOUALLA BIJA

Internal Medicine/Rheumatology

8.

SOBNGWI Eugène

Internal Medicine/Endocrinology

9.

YONE PEFURA

Internal Medicine/Pulmonology

 

C. Senior Lecturers

1.

ETOUNDI MBALLA Alain

Internal Medicine/Pulmonology

2.

FOUDA MENYE Hermine Danielle

Internal Medicine/Nephrology

3.

HAMADOU BA

Internal Medicine/Cardiology

4.

KAMGA OLEN Jean Pierre Olivier

Internal Medicine/Psychiatry

5.

KOUOTOU Emmanuel Armand

Internal Medicine/Dermatology

6.

KOWO Mathurin Pierre

Internal Medicine/Hepato- Gastro-enterology

7.

LOBE Emmanuel

Internal Medicine/Nephrology

8.

NDONGO AMOUGOU Sylvie

Internal Medicine/Cardiology

9.

NTONE ENYIME Félicien

Internal Medicine/Psychiatry

10.

ZE Jean Jacques

Internal Medicine/Pulmonology

 

D. Lecturers

1.

BOOMBHI Jérôme

Internal Medicine/Cardiology

2.

KUATE née MFEUKEU KWA Liliane Claudine

Internal Medicine/Cardiology

3.

NGANOU Chris Nadège

Internal Medicine/Cardiology

 

DEPARTMENT OF MEDICAL IMAGERY AND RADIOLOGY

 

A. Professors

1.

GONSU Joseph

Radiology/Medical Imagery

2.

MOUELLE SONE

Radiotherapy

3.

NKO'O AMVENE Samuel

Radiology/Medical Imagery

 

B. Associate Professors

1.

ZEH Odile Fernande (CD)

Radiology/Medical Imagery

2.

GUEGANG GOUJOU. E.

Radiology/Neuroradiology

3.

MOIFO Boniface

Radiology/Medical Imagery

4.

ONGOLO ZOGO Pierre

Radiology/Medical Imagery

 

C. Lecturer

1.

MBEDE Maggy

Radiology/Medical Imagery

 

DEPARTMENT OF GYNAECOLOGY AND OBSTETRCS

 

A. Professors

1.

KASIA Jean Marie (CD)

Gynaecology/Obstetrics

2.

BELLEY PRISO Eugène

Gynaecology/Obstetrics

3.

MBOUDOU Émile

Gynaecology/Obstetrics

4.

MBU ENOW Robinson

Gynaecology/Obstetrics

 

B. Associate Professors

1.

FOUMANE Pascal

Gynaecology/Obstetrics

2.

KEMFANG NGOWA J.D.

Gynaecology/Obstetrics

3.

NANA NJOTANG Philip

Gynaecology/Obstetrics

4.

NKWABONG Elie

Gynaecology/Obstetrics

5.

TEBEU Pierre Marie

Gynaecology/Obstetrics

 

C. Senior Lecturers

1.

BELINGA Etienne

Gynaecology/Obstetrics

2.

DOHBIT Julius SAMA

Gynaecology/Obstetrics

3.

FOUEDJIO Jeanne H.

Gynaecology/Obstetrics

4.

ESSIBEN Félix

Gynaecology/Obstetrics

5.

MVE KOH Valère Salomon

Gynaecology/Obstetrics

6.

NGO UM Esther Juliette épse MEKA

Gynaecology/Obstetrics

7.

NOA NDOUA Claude Cyrille

Gynaecology/Obstetrics

 

DEPARTMENT OF OPHTALMOLOGY, ORL AND STOMATOLOGY

 

A. Professors

1.

NDJOLO Alexis (CD)

ORL

2.

BELLA Assumpta Lucienne

Ophthalmology

3.

EBANA MVOGO Côme

Ophthalmology

4.

NJOCK Richard

ORL

 

B. Associate Professors

1.

DJOMOU François

ORL

3.

ELLONG Augustin

Ophthalmology

4.

ÉPÉE Émilienne

Ophthalmology

 

C. Senior Lecturers

1.

BILLONG Yannick

Ophthalmology

2.

DOHVOMA Andin Viola

Ophthalmology

3.

EBANA MVOGO Stève Robert

Ophthalmology

4.

KAGMENI Gilles

Ophthalmology

5.

KOKI Godefroy

Ophthalmology

6.

NGABA Olive

ORL

 

DEPARTMENT OF PEDIATRICS

 

A. Professors

1.

KOKI NDOMBO Paul (CD)

Paediatrics

2.

MONEBENIMP Francisca

Paediatrics

 

B. Associate Professors

1.

CHELO David

Paediatrics

2.

CHIABI Andreas

Paediatrics

3.

MAH Evelyn

Paediatrics

4.

NGUEFACK Séraphin

Paediatrics

 

C. Senior Lecturers

1.

KALLA Ginette Claude épse MBOPI KEOU

Paediatrics

2.

MBASSI AWA

Paediatrics

3.

NGO UM KINJEL Suzanne épse SAP

Paediatrics

4.

NGUEFACK épouse DONGMO Félicitée

Paediatrics

5.

NOUBI N. épouse KAMGAING M.

Paediatrics

6.

ONGOTSOYI Angèle H.

Paediatrics

 

DEPARTMENT OF MICROBIOLOGY, PARASITOLOGY, HEMATOLOGY AND INFECTIOUS DISEASES

 

A. Professors

1.

MBOPI KEOU François-Xavier (CD)

Bacteriology/Virology

2.

ADIOGO Dieudonné

Microbiology/Virology

3.

LUMA Henry

Bacteriology/Virology

4.

MBANYA Dora

Haematology

 

B. Associate Professors

1.

NKOA Thérèse

Microbiology /Haematology

2.

OKOMO ASSOUMOU Marie C.

Bacteriology/ Virology

3.

GONSU née KAMGA Hortense

Bacteriology

4.

TAYOU TAGNY Claude

Microbiology/Haematology

5.

TOUKAM Michel

Microbiology

 

C. Senior Lecturers

1.

CHETCHA CHEMEGNI Bernard

Microbiology/Haematology

2.

KINGE Thomson Njie

Infectious Diseases

3.

LYONGA Emilia ENJEMA

Medical Microbiology

 

D. Lecturers

1.

BEYELA Frédérique

Infectious Diseases

2.

NDOUMBA NKENGUE Annick épse MINTYA

Virology

3.

VOUNDI VOUNDI Esther

Virology

 

DEPARTMENT OF PUBLIC HEALTH

 

A. Professor

1.

MONEBENIMP Francisca (CD)

Paediatrics

 

B. Associate Professors

1.

KAMGNO Joseph

Public Health/Epidemiology

2.

TAKOUGANG Innocent

Public Health

3.

TANYA née NGUTI K. A.

Nutrition

4.

ESSI Marie Josée

Public Health /Medical Anthropology

5.

NGUEFACK TSAGUE

Public Health /Biostatistics

 

C. Senior Lecturer

1.

BILLONG Serges Clotaire

Public Health

2.

BEDIANG Georges Wylfred

Medical Information Technology/ Public Health

3.

KEMBE ASSAH Félix

Epidemiology

4.

KWEDI JIPPE Anne Sylvie

Epidemiology

5.

NJOUMEMI ZAKARIAOU

Public Health /Health Economy

 

DEPARTMENTOF MORPHOLOGIC-ANATOMY PATHOLOGIC SCIENCES

 

A. Professors

1.

ESSAME OYONO

Anatomy Pathology

2.

FEWOU Amadou

Anatomy Pathology

 

B. Associate Professors

1.

SANDO Zacharie (CD)

Anatomy Pathology

 

C. Senior Lecturers

1.

AKABA Désiré

Human Anatomy

2.

KABEYENE OKONO Angèle

Histology/Embryology

3.

MENDIMI NKODO Joseph

Anatomy Pathology

 

D. Lecturers

1.

NSEME Eric

Legal Medicine

 

DEPARTMENT OF BIOCHEMISTRY

 

A. Professors

1.

MBACHAM Wilfried

Biochemistry

 

B. Associate Professors

1.

NDONGO EMBOLA épse TORIMIRO Judith (CD)

Physiology/Molecular Biology

2.

PIEME Constant Anatole

Biochemistry

 

C. Senior Lecturers

1.

AMA MOOR Vicky Joceline

Clinical Biology/Biochemistry

 

D. Lecturers

1.

BONGHAM BERINYUI

Biochemistry

 

DEPARTMENT OF PHYSIOLOGY

 

A. Professors

1.

ETOUNDI NGOA Laurent Serges (CD)

Physiology

 

B. Senior Lecturers

1.

ASSOMO NDEMBA Peguy Brice

Physiology

2.

AZABJI KENFACK Marcel

Physiology

 

C. Lecturers

3.

DZUDIE TAMDJA Anastase

Physiology

 

DEPARTMENT OF PHARMACOLOGY AND TRADITIONAL MEDICINE

 

A. Professors

1.

NGADJUI CHALEU Bonaventure

Pharmacy/Phytochemistry

 

B. Senior Lecturers

1.

NGONO MBALLA Rose ABONDO (CD)

African Pharmaco-therapeutics

2.

NDIKUM Valentine

Pharmacology

 

DEPARTMENT OF BUCCAL SURGERY, MAXILLO-FACIAL AND PARODONTOLOGY

 

A. Professors

1.

BENGONDO MESSANGA Charles(CD)

Stomatology

 

B. Senior Lecturers

1.

MINDJA EKO David

ORL/ Maxillo-Facial Sugery

 

C. Lecturers

1.

BITHA BEYIDI Thècle Rose Claire

Maxillo Facial Surgery

2.

GAMGNE GUIADEM C.M

Dental Surgery

3.

NOKAM TAGUEMNE M.E.

Dental Surgery

 

DEPARTMENT OF PHARMACOTOXICOLOGY AND PHARMACOKINETICS

 

A. Associate Professors

1.

FOKUNANG Charles

Molecular Biology

2.

MPONDO MPONDO Emmanuel

Pharmaco-toxicology/ Pharmacokinetics

 

B. Senior Lecturers

1.

NGUIDJOE Evrard Marcel (CD)

Pharmacology

2.

TEMBE Estella épse FOKUNANG

Pharmacokinetic

3.

TABI OMGBA

Pharmacy

 

DEPARTMENT OF PHARMACOGNOSIA AND PHARMACEUTIC CHEMISTRY

 

A. Associate Professors

1.

NTSAMA ESSOMBA Claudine (CD)

Pharmacognosia / Pharmaceutic Chemistry

2.

GUEDJE Nicole Marie

Ethnopharmacology/ Plant Biology

3.

NGAMENI Barthélémy

Phytochemistry/ Organic Chemistry

4.

NGOUPAYO Joseph

Phytochemistry/General Chemistry

 

DEPARTMENT OF GALENICAL PHARMACY AND PHARMACEUTIC LEGISLATION

 

A. Associate Professors

 

NNANGA NGA Emmanuel (CD)

Galenical Pharmacy

 

B. Lecturers

 

MBOLE Jeanne Mauricette épse MVONDO M.

Quality Management, Quality Control of Health Products and Food

 

SOPPO LOBE Charlotte Vanessa

Quality Control of Medicines

Key: CD= Chief of Department

THE PHYSICIAN'S OATH

Declaration of Geneva adopted by the Geneva Medical Assembly of the World Medical Association in Geneva, Switzerland, September 1948 and amended by the 22nd World Medical Assembly, Sydney, Australia (August 1968).

On admission to the medical profession:

I solemnly pledge myself to consecrate my life to the service of humanity;

I will give my teachers the respect and gratitude which is their due;

I will practice my profession with conscience and dignity;

The health of my patients will be my first consideration;

I will respect secrets confided in me, even after the patient has died;

I will maintain by all the means in my power the honour and noble traditions of the medical profession;

My colleagues will be my brothers and sisters;

I will not permit considerations of religion, nationality, race, political party or social standing to intervene between my duty and my patient;

I will maintain the utmost respect for human life from the time of conception, even under threat I will not use my medical knowledge contrary to the laws of humanity;

I make these promises solemnly, freely and upon my honour.

LIST OF TABLES

Table I: The French Classification of Pediatric Hypertension 15

Table II:The American Classification of Pediatric Hypertension 15

Table III: Causes of secondary hypertension in Pediatrics 20

Table IV: Physical findings indicative of secondary cause of Pediatric Hypertension 30

Table V: Recommended Dimensions for Blood Pressure Cuff Bladders 32

Table VI: Indicated paraclinical work-ups in case of Hypertension 35

Table VII: Selected primary schools for the study 48

Table VIII: Distribution of pupils by gender 59

Table IX: Distribution of pupils by age 59

Table X: Distribution of pupils by type of school and school setting 60

Table XI: Distribution of pupils by class 60

Table XII: Distribution by profession of legal tutor 61

Table XIII: Distribution by socio-economic status 61

Table XIV: Body Mass Index classification among study subjects 62

Table XV: Distribution of overweight/obesity by age range 2

Table XVI: Distribution of overweight/obesity by gender 63

Table XVII: Prevalence of Elevated Blood Pressure and Hypertension (at third screening) 65

Table XVIII: Prevalence of elevated SystolicBlood Pressure and Diastolic Blood Pressure 2

Table XIX: Prevalence of Elevated Blood Pressure and hypertension with respect socio-demographic characteristics and anthropometric parameters 66

Table XX: Correlation between blood pressure and, age and Body Mass Index 67

Table XXI: Socio-demographic status and hypertension 70

Table XXII: Socio-economic status and Hypertension 71

Table XXIII: Feeding habits and Hypertension 72

Table XXIV: Physical exercise and sedentarity and Hypertension 73

Table XXV: Past history and Hypertension 74

Table XXVI: Body Mass Index status and Hypertension 75

Table XXVII: Multivariate analysis with logistic regression 76

LIST OF FIGURES

Figure 1: Blood Pressure -for-stature percentiles, Boys 3 to 20 years 16

Figure 2: Blood Pressure -for-stature percentiles, Girls 3 to 20 years 17

Figure 3:The heart, arteries and arterioles in hypertension 22

Figure 4: Reninangiotensin system and effects on blood pressure and aldosterone release 23

Figure 5: The autonomic nervous system and its control of blood pressure 24

Figure 6: The control of peripheral arteriolar resistance 25

Figure 7: Virchow's triad and the prothrombotic state in hypertension 26

Figure 8: Possible mechanisms to explain why low birth weight babies are more likely to develop hypertension in later life 28

Figure 9: Management algorithm 38

Figure 10: Measurement of the height 53

Figure 11: Flow diagram of the study 58

Figure 13: Prevalence of hypertension and Elevated Blood Pressure on all 3 screenings 64

Figure 14: Correlation between Systolic Blood Pressure and age 67

Figure 15: Correlation between Diastolic Blood Pressure and age 68

Figure 16: Correlation between Systolic Blood Pressure and Body Mass Index 2

Figure 17: Correlation between Diastolic Blood Pressure and Body Mass Index 69

LIST OF ABBREVIATIONS/ACRONYMS/SYMBOLS

AAP : American Academy of Pediatrics

BP: Blood Pressure

BMI: Body Mass Index

CE1 : Cours Elémentaire 1

CE2 : Cours Elémentaire 2

CM1 : Cours Moyen 1

CM2 : Cours Moyen 2

CP: Cours Préparatoire

CO: Cardiac Output

CVD: Cardiovascular Disease

DASH: Dietary Approaches to Stop Hypertension

DBP: Diastolic Blood Pressure

FDA : Food and Drug Administration

HR:Heart Rate

HTN: Hypertension

LVH: Left Ventricular Hypertrophy

NHBPEP: National High Blood Pressure Education Program

OR : Odd's ratio

SBP : Systolic Blood Pressure

SDG : Sustainable Development Goals

SV: Stroke Volume

TPR: Total Peripheral Resistance

UTI : Urinary Tract Infection

WHO: World Health Organisation

ABSTRACT

BACKGROUND:Hypertension is a major long-term health condition and is the leading cause of premature death among adults throughout the world, including developed, and developing countries. In recent years, there has been a progressive increase in hypertension among children and adolescents. Evidence suggests that, high blood pressure in childhood is a precursor of hypertension in adulthood and its presence is influenced by various risk factors including; childhood obesity, lifestyle changes and hereditary factors. Early diagnosis of hypertension in childhood is an important strategy in its control in order to prevent its serious and long term complications. In Cameroon, there is no available data on hypertension in children in a rural setting.

OBJECTIVES: This study was carried out to determine the prevalence of hypertension and elevated blood pressure; as well as the associated factors to hypertension among primary school children in Mbankomo subdivision, a rural area in theMefou and Akono division, Centre Region.

METHODS: This study was a school based cross-sectional analytic study, carried out within a period of 6 months (from the 21th of November 2017 tothe 22th of May 2018) in 13 primary schools (10 public and 3 private schools) in Mbankomo subdivision. These schools were selected using a 2 stage cluster sampling method. The blood pressure was measured using an aneroid sphygmomanometer. Weight and height were also measured and BMI calculated. Children with a high blood pressure were screened a second and third time at 1 week intervals. Hypertension was defined as high blood pressure on all 3 occasions according to the American Academy of Pediatrics. Analysis was done using a software called Epi-Info™ 3.5.4.The Chi-square test was used to evaluate the association between qualitative variables and the Pearson correlation test was used to evaluate the association between quantitative variables. The degree of association was assessed using the Odd's ratio and its confidence interval at 95%, and statistical significance was considered at a p-value < 0.05.

RESULTS: A total of 822 pupils were included in our study, of which were 353 males and 469 females giving a sex ratio of 0.8. The mean age was 9 years (extremes from 5-17years) and the most represented age range was 8-10 years. The prevalence of hypertension was 1.6% (with 1.5% in stage I and 0.1% in stage II) and that of elevated blood pressure was 8.1%, with a systolic predominance of 1.6%. SBP and DBP had a significant positive correlation with age(r=0.17; p=0.000 andr=0.07; p=0.000 respectively) and BMI(r=0.18; p=0.000 andr=0.11; p=0.000respectively).

The associated factors of hypertension after multivariate analysis were: the pupil's age > 10years (OR=6.4614; CI95=1.2581 - 33.1841; p=0.0254), family history of overweight (OR=7.4624; CI95=1.6906 - 32.9401; p=0.008), and excess weight(OR=10.1069; CI95=2.5094 - 40.7063; p=0.0011)which persisted as risk factors of hypertension, and born at term (OR=0.0845; CI95=0.0216 - 0.3307; p=0.0004) as a protecting factor.

CONCLUSION: The mean age of the pupils enrolled in the study was 9years, and the most represented age range was 8-10 years (41.1%). Females were mostly represented in 57.1% giving a sex ratio of 1.3. Pupils mostly attended public schools in 82.8% and were mostly from a semi urban setting in 56.7%. The most represented class was class 6 in 22.6%. Most legal tutors carried out liberal professions (49.8%) and the most represented socio economic status was that of the middle class in 87.5%.

The prevalence of hypertension was 1.6% (with 1.5% in stage I and 0.1% in stage II) and that of elevated BP was 8.1%.Hypertension was predominantly systolic in 1.6%, and diastolic in 0.4%. There was a positive correlation between age, BMI, and blood pressure.

After multivariate analysis with logistic regression, only the age> 10years, family history of overweight, excess weight persisted as risk factors of HTN, and born at term as a protecting factor.

RECOMMENDATIONS:We thus recommend that nutrition and physical education courses need to be reinforced in the school curricular; that blood pressure monitoring be integrated as part of routine clinical examination during medical visits of healthy and sick children; and that the parents should encourage healthy eating habits at home and in school and, ensure manual labour and physical activity at home.

Keywords: Hypertension, elevated blood pressure, pupils, rural, associated factors.

RESUME

CONTEXTE: L'hypertension est un problème de santé majeur à long terme et la principale cause de décès prématuré chez les adultes dans le monde, y compris dans les pays développés et en développement. Au cours des dernières années, il y a eu une augmentation progressive de l'hypertension chez les enfants et les adolescents. Les études suggèrent que, l'hypertension artérielle dans l'enfance est un précurseur de l'hypertension à l'âge adulte et sa présence est influencée par divers facteurs de risque, y compris; l'obésité infantile, les changements de mode de vie et les facteurs héréditaires. Le diagnostic précoce de l'hypertension chez l'enfant est une stratégie importante dans son contrôle afin de prévenir ses complications graves et à long terme. Au Cameroun, il n'existe pas de données disponibles sur l'hypertension chez les enfants en milieu rural.

OBJECTIFS: Cette étude a été réalisée pour déterminer la prévalence de l'hypertension artérielle et de l'hypertension artérielle limite; ainsi que les facteurs associés à l'hypertension artérielle chez les enfants du primaire dans l'arrondissement de Mbankomo,une zone rurale dansle département de la Mefou et Akono, région du Centre.

METHODES: Cette étude était une étude transversale analytique en milieu scolaire, réalisée sur une période de 6 mois (du 21 Novembre 2017 au22 Mai 2018) dans 13 écoles primaires (10 écoles publiques et 3 écoles privées) dans l'arrondissement de Mbankomo. Ces écoles ont été sélectionnées en utilisant un échantillonnage en grappes à deux degrés. La pression artérielle a été mesurée en utilisant un sphygmomanomètre anéroïde. Le poids et la taille ont également été mesurés et l'IMC a été calculé. Les enfants ayant une pression artérielle élevée ont été examinés une deuxième et une troisième fois à des intervalles d'une semaine. L'hypertension a été définie comme l'hypertension artérielle à toutes les 3 reprises selon l'Académie Américaine de Pédiatrie. L'analyse a été faite en utilisant un logiciel appelé Epi-Info ™ 3.5.4. Le test de Chi-carre a été utilisé pour évaluer l'association entre les variables qualitatives et le test de corrélation de Pearson a été utilisé pour évaluer l'association entre les variables quantitives. Le degré d'association a été évalué en utilisant le Odd ratio et son intervalle de confiance à 95%, et le niveau de significativitéa été considérée à P <0,05.

RESULTATS: Un total de 822 élèves ont été inclus dans notre étude, dont 353 garçons et 469 filles donnant un sex-ratio de 0,8. L'âge moyen était de 9 ans (extrêmes de 5 à 17 ans) et la tranche d'âge la plus représentée était de 8 à 10 ans.

La prévalence de l'hypertension artérielleétait de 1,6% (1,5% au stade I et 0,1% au stade II) et celle de l'hypertension artérielle limite était de 8,1%, avec une prédominance systolique de 1,6%.

La PAS et PAD avaient une corrélation positive significative avec l'âge(r=0.17; p=0.000 et r=0.07; p=0.000 respectivement) et l'IMC(r=0.18; p=0.000 et r=0.11; p=0.000 respectivement). Les facteurs associés à l'hypertension après analyse multivariée étaient: l'âge de l'élève > 10ans(OR=6.4614; IC95=1.2581 - 33.1841; p=0.0254), les antécédents familiaux de surpoids(OR=7.4624; IC95=1.6906 - 32.9401; p=0.008), et le surpoids(OR=10.1069; IC95=2.5094 - 40.7063; p=0.0011) qui persistaient comme facteurs de risque de l'hypertension artérielle et, être né à terme(OR=0.0845; IC95=0.0216 - 0.3307; p=0.0004) qui persistait comme facteur protecteur.

CONCLUSION:L'âge moyen des élèves inclus dans l'étude était de 9ans, et la tranche d'âge la plus représentée était celle de 8 à 10 ans (41,1%). Les filles étaient principalement représentées dans 57,1%, donnant un sex-ratio de 1,3. La plupart des élèves fréquentaient des écoles publiques dans 82,8% des cas et provenaient principalement d'un milieu semi-urbain dans 56,7% des cas. La classe la plus représentée était le CM2 dans 22,6% des cas. La plupart des tuteurs légaux exercent des professions libérales (49,8%) et le statut socioéconomique le plus représenté etait celui de la classe moyenne dans 87,5% des cas.

La prévalence de l'hypertension était de 1,6% (1,5% au stade I et 0,1% au stade II) et celle de l'hypertension artérielle limite était de 8,1%. L'hypertension avait une prédominance systolique de 1,6% et diastolique de 0,4%. Il y avait une corrélation positive entre l'âge, l'IMC et la pression artérielle.

Après une analyse multivariée avec régression logistique, seuls l'âge> 10ans, les antécédents familiaux de surpoids, l'excès de poids persistaient comme facteurs de risque de HTN, et être né à terme comme facteur de protection.

RECOMMANDATIONS: Nous recommandons donc que les cours de nutrition et d'éducation physique soient renforcés dans le programme scolaire; que la surveillance de la pression artérielle doit être intégrée dans le cadre de l'examen de routine lors de visites médicales des enfants en bonne santé / malades; et que les parents devraient encourager de saines habitudes alimentaires à la maison et à l'école, et assurer une activité physique à la maison.

Mots-clés: Hypertension artérielle, élève, rural, facteurs associés.

CHAPTER I: INTRODUCTION

According to the World Health Organization (WHO), hypertension in adults is defined as a rise in blood pressure levels above normal limits characterized by systolic blood pressure equal to or above 140mmHg and /or diastolic blood equal to or above 90mmHg[1]. In children, the National High Blood Pressure Education Program Working Group (NHBPEP) defined hypertension in children as either systolic and/or diastolic blood pressure = 95th percentile measured on three or more occasions''[2,3].

WHO estimates that, approximately 40% of adults aged 25 are diagnosed as having hypertension; the number of people with the condition rose from 600million in 1980 to 1 billion in 2008[1,4]. In children, the prevalence as reported by various studies, ranges from 5.4% to 19.4%-'-''[2,5-8] with an increase in trends in the last two decades.

Globally, cardiovascular disease accounts for approximately 17million deaths a year, nearly one third of the total[9]. Of these, complications of hypertension account for 9.4million deaths every year---------[10]. Several studies have provided evidence that hypertension in adults has its origin from childhood--'''''''''''''''-'[11-13].

Public health implications of hypertension in children are overwhelming because many of these individuals will eventually face medical sequelae in adulthood when undiagnosed, which can lead to death and cardiovascular disability due to target organ damage: Left Ventricular Hypertrophy (LVH), thickening of carotid vascular wall, retinal vascular damage, kidney damage, cognitive impairment and death in worst cases'-[6,7,12,14,15].

Overweight and obesity are strongly correlated risk factors to primary hypertension in children-'[7,13,16-18]. Family history of hypertension or cardiovascular disease, male sex, maternal smoking during pregnancy and race(to a lower extent) are additional risk factors[16,18]. In the same light, renal parenchymal disease and renovascular diseases account for most cases of secondary hypertension predominant in children and adolescents as compared to adults[16,17].

According to the Task Force recommendations on blood pressure control in children, every child 3 years and older should have his/her Blood Pressure (BP) measured on every healthy/sick visit. This will lead to early diagnosis and identification of those at risk is an important strategy for public health control and prevention of cardiovascular diseases[19].

In America, 65% of hypertensive children identified were referred to a clinic for history of elevated blood pressure, amongst which, 43% had essential hypertension and 57% had secondary hypertension. Those with essential hypertension had a significantly older age at diagnosis and stronger family history of hypertension[14].

Amritanshu et al in India in 2015, showed a prevalence of 4.7% in children and adolescents aged 5 to 19 years of life which was significantly associated with family history of hypertension, type of diet, and additional salt intake and showed a gradual increase over age[20].

In Africa, particularly in urban Sudan, the prevalence of hypertension in children was 4.9% and obesity was found out to be strongly associated with hypertension in primary school children-[21]. Ugwuja et al in 2015 in a rural Agrarian community in Southeast Nigeria found a prevalence of 23.2% and, showed that the age, the consumption of red meat, body mass index and the number of children in the family were associated with hypertension, in patients aged 18years and above[22]. For Okoh Ba et al in 2012 in Nigeria, the prevalence of hypertension in primary school children was 4.7% and a higher BMI was demonstrated significantly associated with a higher prevalence of hypertension[23].

In Cameroon, studies carried out Bertoua, Yaounde and Buea revealed that the prevalence among school children varied between 2.2 - 3.2% and strongly associated with overweight but no significant association with family history of HTN-''''''''''''''''''''''''''''''''''''''''''''''''''''''`'''''''''''''[24-26].

A few studies on blood pressure in school children in the Centre region were done in Yaounde, an urban setting and none in the rural areas. We thus decided to undertake this study in the Mbankomo subdivision, a rural area in theMefou and Akono division, in the Centre Region, to see thetrends of high blood pressure in school children and assess the factors which influence its occurrence in this setting.

CHAPTER II: JUSTIFICATION OF STUDY

The measure of blood pressure is not carried out systematically during pediatric consultations. This leads to discovery of hypertension only whensigns of severity occur. Studies in many parts of the world, have demonstrated a higher blood pressure prevalence in urban zones[27].

In Cameroon, most studies on HTN in children were carried out in urban and semi-urban settings -''''''''''''''''''''''''''''''''''''''''''''''''''''''`'''''''''''''[24-26]. The prevalence varied between 2.2% in Yaounde'''''''''''''''''''''''`'''''''''''''[25], 2.9% in Bertoua'''''''''''''''''''''''''''''''[24] and 3.2% in Buea[26].Lifestyle in urban and rural settings are different, and knowing its influence on HTN, we decided to carry out this study in a rural setting. The Mbankomo subdivision found in the Centre region was thereby chosen, because of its easy access and the abundance of schoolsit has.

From our results, we will draw conclusions and recommendations to help raise awareness of pediatric HTN; promote screening as well as ensure early management and foster educational programs on healthy lifestyle from childhood. This will go a long way to achieve the sustainable development goal(SDG) 3.4--[28], which aims by the year 2030,at reducing by one third premature mortality from non-communicable diseases through prevention and treatment and promote mental health and well-being by the year 2030.

CHAPTER III: RESEARCH QUESTION

What is the prevalence and associated factors of hypertension in primary school children in Mbankomo subdivision found in theMefou and Akono division, Centre Region?

CHAPTER IV: RESEARCH HYPOTHESIS

Hypertension exists in primary school children of Mbankomo subdivision, with associated factors.

CHAPTER V: OBJECTIVES

ü General Objective

· Determine the prevalence and associated factors of hypertension in children attending primary schools in Mbankomo subdivision found in theMefou and Akono division, Centre Region.

ü Specific Objectives

· Assess the socio-demographic characteristics of primary school children in the Mbankomo subdivision.

· Determine the prevalence of elevated BP and hypertension among primary school children in Mbankomo subdivision.

· Determine the factors associated to hypertension in this population.

CHAPTER Vi: literature revIEW

VI.1 OVERVIEW

VI.1.1DEFINITION OF TERMS AND CONCEPTS

· Childhood: This is the period of life between infancy and onset of puberty and is usually between 2 and 10 years inclusive[29].

· Adolescence: This is the transition period of life between childhood and adulthood and is between 11 and 19years of age[30].

· Childhood hypertension: It refers to BP equal to or over the age- and gender-specific 95th percentile value[19].

· Prehypertension: It is considered as BP equal or greater than 90th percentile and less than 95th percentile for age, height, and gender or BP equal or more than 120/80mmHg[19].

· Body mass index (BMI): It is a simple index of weight and height that is commonly used to classify overweight and obesity in adults. It is the weight in kilograms divided by the square of the height in meters[31].

· Childhood obesity: Children with BMI equal or greater than the age-gender-specific 95th percentile of growth chart[31].

· Childhood overweight: BMI equal or greater than 85th percentile but less than the age-gender specific 95th percentile of growth chart[31].

· Normal weight: BMI equal or greater than 5th percentile but less than the age-gender specific 85thpercentile of growth chart[31].

· Underweight: BMI less than the age-gender specific 5thpercentile of the growth chart[31].

VI.1.2EPIDEMIOLOGY

In terms of non-communicable diseases in children, HTN comes second following Asthma and Obesity[32]. The true incidence of hypertension in paediatric population is unknown[33]. The prevalence is increasing in accordance with widespread life-style changes and epidemic of childhood obesity[23]. Alarming data exist on the prevalence of childhood HTN not only in industrialized countries, but also in developing countries'-[6,34]. Because of differences in genetic and environmental factors, incidences vary from country to country and even from region to region in the same country[33,35]. The prevalence of HTN among children reported by various studies ranges from 5.4% to 19.4%[5,36]. The prevalence appears to be increasing and is estimated to be 1% to 4% in Europe and 4% to 14% in the USA[35,37]. In Sub-Saharan Africa: 4.9% in Sudan [5]; 11.4% in South Africa[38]; 10% in Congo'-[6]; 4.7% in Port Harcourt, Nigeria[23]. In Cameroon: 2.2% in Yaoundé '''''''''''''''''''''''`'''''''''''''[25], 2.9% in Bertoua'''''''''''''''''''''''''''''''[24]and 3.2% in Buea[26].

BP in children varies with age, gender, and height. However, these relations do not become evident until children reach school age (3 years) [33,39]. Numerous investigators have noted a correlation between BP of parents and their offspring[40]. Familial aggregation of BP is detectable early in life. Some data relate this association to concomitant obesity in both parents and child[8].

Moreover, studies have shown that there are no significant differences in BP between girls and boys younger than 6 years. From that age until puberty, BP is slightly higher in girls than in boys. At puberty and beyond, BP is slightly higher in male adolescents than in comparable aged femaleadolescents[35,39,41,42].

There are no differences in BP between African American and white children[8,41].

VI.1.3CLASSIFICATION

Pediatric HTN is defined and classified by two different consensus[19,43]:

ü The French consensus

According to the French consensus, normal BP in children is defined as SBP and DBP less than 97.5th percentile for age, sex and height[43]; Paediatric HTN defined as SBP and/or DBP equal or more than 97.5th percentile for age, sex and height taken on at least 3 separate occasions[19,43]. This school of thought further classified Pediatric HTN into 3 stages as follows:

Table I: The French Classification of Pediatric HTN[43]

STAGE

SBP and/or DBP percentile

Normal

< 97.5th percentile

Limited or Moderate hypertension

= 97.5th to <97.5th percentile + 10mmHg

Confirmed hypertension

= 97.5th + 10mmHg to <97.5th percentile + 30mmHg

Emergency hypertension

= 97.5th percentile + 30mmHg

Source:Andre J. Hypertension artérielle chez l'enfant et l'adolescent. EMC - Cardiol-Angéiologie. 2005 Nov;2(4):478-90.

ü The American Consensus

According to the AAP(American Academy of Pediatrics) in 2017[44] which revised the Fourth Report on Blood Pressure Control in Children of NHBPEP[19], the normal BP in children is defined as BP less than 90thpercentile for age, sex and height. Paediatric HTN is defined as BP of 95th percentile or more, measured on at least three separate occasions using the auscultatory method[44]. This school classifies paediatric HTN into 4 classes as follows:

Table II: American Classification of Pediatric HTN[44]

For Children Aged 1-13 years

For Children Aged =13 years

Normal BP: <90thpercentile

Normal BP:<120/<80 mm Hg

Elevated BP: =90thpercentile to <95th percentile or 120/80 mm Hg to <95th percentile (whichever is lower)

Elevated BP: 120/<80 to 129/<80 mm Hg

Stage 1 HTN: =95thpercentile to <95thpercentile + 12 mmHg,or 130/80 to 139/89 mm Hg (whichever is lower)

Stage 1 HTN: 130/80 to 139/89 mm Hg

Stage 2 HTN: =95thpercentile + 12 mm Hg, or =140/90 mm Hg (whichever is lower)

Stage 2 HTN: =140/90 mm Hg

Source:-Flynn JT, Kaelber DC, Baker-Smith CM, et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Pediatrics. 2017;140(3):e20171904..

Presented below are charts showing the approximation of blood pressure centiles from the task force report on BP control in children''[45] :

Figure 1: BP-for-stature percentiles, Boys 3 to 20 years

Source: Ashish B, Cynthia B, Monesha GM, Joshua S. Blood pressure percentile charts to identify high or low blood pressure in children. BMC Pediatrics. (2016);16:98.

Figure 2: BP-for-stature percentiles, Girls 3 to 20 years

Source: Ashish B, Cynthia B, Monesha GM, Joshua S. Blood pressure percentile charts to identify high or low blood pressure in children. BMC Pediatrics. (2016);16:98.

VI.1.3.1HISTORY OF THE PRESENT DEFINITION AND CLASSIFICATION OF PEDIATRIC HYPERTENSION

In 1977, the first Report of the Task Force on Blood Pressure Control in Children was published in the United States [46], with the aim of standardizing measuring and monitoring methods; standardizing distribution curves of arterial BP in healthy children; and of organizing BP into percentile graphs according age and sex[46]. In this study, the 95thpercentile was established as normotensive levels and the recommendation that «All children 3 years of age or older should have their BP measured during any health maintenance visits or emergency visits». Since then, series of nationwide and international studies have been undertaken and new concepts elaborated.

In 1987, the 2nd Report of the Task Force on BP Control in Children was released which established that «Normal BP is less 90thpercentile for age, sex and height: and HTN greater than 95thpercentile» and this report also recommended «5th phase korotkoff sound as reference for DBP[19].

The Third Report of the Task Force, published in 1996, provided further details regarding the diagnosis and treatment of HTN in infants and children.

In 2004, the Fourth Report later introduced, prehypertension, Stage 1 HTN and Stage 2 HTN. This classification was created to align the categories for children with the categories for adults from the recommendations of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension[19].

In 2017, the AAP updated the 2004 «Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents» by making the following major changes; the replacement of the term `prehypertension' with the term `elevated blood pressure', new normative pediatric blood pressure (BP) tables based on normal-weight children, a simplified screening table for identifying BPs needing further evaluation, a simplified BP classification in adolescents =13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, a more limited recommendation to perform screening BP measurements only at preventive care visits, streamlined recommendations on the initial evaluation and management of abnormal BPs, an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and revised recommendations on when to performechocardiography in the evaluation of newly diagnosed hypertensivepediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy[44].

VI.1.4ETIOLOGIES

There exists 2 forms of HTN: Essential and Secondary HTN[12,19,44].

Secondary HTN is defined as HTN which occurs as a result of an underlying disorder. When no identifiable cause is found, it is referred to as Primary or Essential HTN.

Essential hypertension is mostly found in adults as compared to that found in children and adolescents''[2,19,47]. Significant determinants for essential hypertension include family history of hypertension, cardiovascular disease, and obesity as well as low birth weight, insulin resistance, sedentarity, salt consumption and tobacco intake'[13,19]. Some sleep disorders like: Obstructive sleep apnea, insomnia, and restless legs syndrome have been reported to be associated with essential hypertension [15,48].

Secondary hypertension which the most common form, is more common in children than in adults''[2,19,35]. It can be present in adolescents, especially if they have physical findings not typically seen with essential hypertension.67% to 80% of secondary HTN are of renal origin with 34.89% being nephrotic syndrome'''''''''''''''''''''''''''''''[24]. Other causes include endocrine disease (e.g pheochromocytoma, hyperthyroidism) and pharmaceuticals (e.g., oral contraceptives, sympathomimetics, some over-the counter medications, dietary supplements). Transient rise in blood pressure, which can be mistaken for hypertension, is seen with caffeine use and certain psychological disorders (anxiety and stress)[49,50].The causes of secondary HTN can be seen on the following table:

Table III: Causes of secondary hypertension in Pediatrics[19]

CAUSE

ABNORMALITY

CONDITION

Renal

Parenchymal

· Glomerulonephritis

· Chronic kidney failure

· Hemolytic uremic syndrome

· Polycystic kidney disease

· Tumor(nephroblastoma)

Renovascular

· Renal artery stenosis(fibromuscular dysplasia, Takayasu disease)

· Multiple vascular lesions(neurofibromatosis, panarterities, renal artery thrombrosis)

Endocrine

 

· Cushing syndrome

· Pheochromocytoma

· Primary hyperaldosteronism

Vascular

 

· Coarctation of aorta

· Angiodysplasia

Metabolic

 

· Hypercalcemia

· Porphyria

Exogenous

 

· Corticotherapy

· Vitamin D intoxication

· Cyclosporine

· Amphetamine

Sources:- National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004 Aug; 114(2 Suppl 4th Report):555-76.

VI.1.5 RISK FACTORS

Hypertension is a multifactorial disease, influenced by genetic, racial, geographic, cultural and dietary pattern[8]. Identifying and modifying the risk factors, reduces the incidence and complications in adults[16].Studies have noted a strong association between overweight, obesity and high BP. In particular, obesity epidemic appears to be the major contributor of the increasing trends in childhood HTN[16,35,41,49].

However, apart from obesity, other factors such as: dietaryhabits, lack of physical activity, sedentary behaviour, as well as increase dietary salt intake have been associated with increased BP in children independent of body composition. These include[8]:

· Abnormal lipid profile

· Overweight and Obesity

· Insulin resistance

· Increased salt intake

· Family history of hypertension

· Low birth weight

· Sedentary lifestyle

VI.1.6 PATHOPHYSIOLOGY

Blood Pressure(BP) is determined by a balance between cardiac output and vascular resistance.

Based on Franck Starling formula[51]:

BP = Cardiac output(CO) × Total Peripheral Resistance(TPR)

A rise in either of these variables, in the absence of a compensatory decrease in the other, increases mean BP, which is the driving pressure[52]. The total peripheral resistance reflects the vasomotor tone generated by the arteries (mostly those of small calibre) and volemia to a lower extent[52,53].Contraction of smooth muscle cells is thought to be related to a rise in intracellular calcium concentration, which may explain the vasodilatory effect of drugs that block the calcium channels. Prolonged smooth muscle constriction is thought to induce structural changes with thickening of the arteriolar vessel walls possibly mediated by angiotensin, leading to an irreversible rise in peripheral resistance[53].The cardiac output is the product of heart rate(HR) and stroke volume(SV):

CO = HR xSV

The stroke volume depends on the quantity of blood present in the left ventricle at the end of diastole and the heart rate depends on the equilibrium between the sympathetic and the parasympathetic systems[52].

It has been postulated that in very early hypertension the peripheral resistance is not raised and the elevation of the blood pressure is caused by a raised cardiac output, which is related to sympathetic over-activity. The subsequent rise in peripheral arteriolar resistance might therefore develop in a compensatory manner to prevent the raised pressure being transmitted to the capillary bed where it would substantially affect cell homeostasis[53].

Figure 3:The heart, arteries and arterioles in hypertension[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

The reninangiotensin system may be the most important of the endocrine systems that affect the control of blood pressure. Renin is secreted from the juxtaglomerular apparatus of the kidney in response to glomerular under perfusion or a reduced salt intake. It is also released in response to stimulation from the sympathetic nervous system[53].

Renin is responsible for converting renin substrate (angiotensinogen) to angiotensin I, a physiologically inactive substance which is rapidly converted to angiotensin II in the lungs by angiotensin converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor and thus causes a rise in blood pressure. In addition it stimulates the release of aldosterone from the zona glomerulosa of the adrenal gland, which results in a further rise in blood pressure related to sodium and water retention[53].

The circulating reninangiotensin system is not thought to be directly responsible for the rise in blood pressure in essential hypertension. In particular, many hypertensive patients have low levels of renin and angiotensin II (especially elderly and black people), and drugs that block the reninangiotensin system are not particularly effective[53].

There is, however, increasing evidence that there are important noncirculating «local» reninangiotensin epicrine or paracrine systems, which also control blood pressure.

Local renin systems have been reported in the kidney, the heart, and the arterial tree. They may have important roles in regulating regional blood flow[53].

Figure 4: Reninangiotensin system and effects on blood pressure and aldosterone release[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

Sympathetic nervous system stimulation can cause both arteriolar constriction and arteriolar dilatation. Thus the autonomic nervous system has an important role in maintaining a normal blood pressure. It is also important in the mediation of short term changes in blood pressure in response to stress and physical exercise.

There is, however, little evidence to suggest that epinephrine(adrenaline) and norepinephrine (noradrenaline) have any clearrole in the aetiology of hypertension.Nevertheless, their effects are important, not least because drugs that block the sympathetic nervous system do lower blood pressure and have a well-establishedtherapeutic role[53].

It is probable that hypertension is related to an interaction between the autonomic nervous system and the reninangiotensin system, together with other factors, including sodium, circulating volume, and some of the more recently described hormones[53].

Figure 5: The autonomic nervous system and its control of blood pressure[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

Vascular endothelial cells play a key role in cardiovascular regulation by producing a number of potent local vasoactive agents, including the vasodilator molecule nitric oxide and the vasoconstrictor peptide endothelin. Dysfunction of the endothelium has been implicated in human essential hypertension[53].

Modulation of endothelial function is an attractive therapeutic option in attempting to minimise some of the important complications of hypertension. Clinically effective antihypertensive therapy appears to restore impaired production of nitric oxide, but does not seem to restore the impaired endothelium dependent vascular relaxation or vascular response to endothelial agonists. This indicates that such endothelial dysfunction is primary and becomes irreversible once the hypertensive process has become established[53].

Many other vasoactive systems and mechanisms affecting sodium transport and vascular tone are involved in the maintenance of a normal blood pressure. It is not clear, however, what part these play in the development of essential hypertension. Bradykinin is a potent vasodilator that is inactivated by angiotensin converting enzyme. Consequently, the ACE inhibitors may exert some of their effect by blocking bradykinin inactivation[53].

Endothelin is a recently discovered, powerful, vascular, endothelial vasoconstrictor, which may produce a salt sensitiverise in blood pressure. It also activates local reninangiotensin systems. Endothelial derived relaxant factor, now known to be nitric oxide, is produced by arterial and venous endothelium and diffuses through the vessel wall into the smooth muscle causing vasodilatation.

Atrial natriuretic peptide is a hormone secreted from the atria of the heart in response to increased blood volume. Its effect is to increase sodium and water excretion from the kidney as a sort of natural diuretic. A defect in this system may cause fluid retention and hypertension[53].

Sodium transport across vascular smooth muscle cell walls is also thought to influence blood pressure via its interrelation with calcium transport. Ouabain may be a naturally occurring steroidlike substance which is thought to interfere with cell sodium and calcium transport, giving rise to vasoconstriction.

Figure 6: The control of peripheral arteriolar resistance[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

Patients with hypertension demonstrate abnormalities of vessel wall (endothelial dysfunction or damage), the blood constituents (abnormal levels of haemostatic factors, platelet activation, and fibrinolysis), and blood flow (rheology, viscosity, and flow reserve), suggesting that hypertension confers a prothrombotic or hypercoagulable state. These components appear to be related to target organ damage and long term prognosis, and some may be altered by antihypertensive treatment[53].

Figure 7: Virchow's triad and the prothrombotic state in hypertension[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

Epidemiologically there is a clustering of several risk factors, including obesity, hypertension, glucose intolerance, diabetes mellitus, and hyperlipidaemia. In obese children, hyperinsulinemia may elevate BP by increasing sodium reabsorption and sympathetic tone. The complexity of the system explains the difficulties often encountered in identifying the mechanism that accounts for HTN. These difficulties are the main reasons why treatment is often designed to affect regulatory factors rather than the cause of the disease[48,50].

Indeed some hypertensive patients who are not obese display resistance to insulin. There are many objections to this hypothesis, but it may explain why the hazards of cardiovascular risk are synergistic or multiplicative rather than just additive.Although separate genes and genetic factors have been linked to the development of essential hypertension, multiple genes are most likely contribute to the development of the disorder in a particular individual. It is therefore extremely difficult to determine accurately the relative contributions of each of these genes.

Nevertheless, hypertension is about twice as common in subjects who have one or two hypertensive parents, and many epidemiological studies suggest that genetic factors account for approximately 30% of the variation in blood pressure in various populations. This figure can be derived from comparisons of parents with their monozygotic and dizygotic twin children, as well as their other children, and with adopted children. Some familial concordance is, however, due to shared lifestyle (chiefly dietary) factors[53].

Some specific genetic mutations can rarely cause hypertension. Experimental models of genetic hypertension have shown that the inherited tendency to hypertension resides primarily in the kidney. For example, animal and human studies show that a transplanted kidney from a hypertensive donor raises the blood pressure and increases the need for antihypertensive drugs in recipients coming from «normotensive» families. Conversely a kidney from a normotensive donor does not raise the blood pressure in the recipient.

Increased plasma levels of angiotensinogen, the protein substrate acted on by renin to generate angiotensin I, have also been reported in hypertensive subjects and in children of hypertensive parents.

Hypertension is rarely found in rural or «tribal» areas of Africa, but it is very common in African cities and in black populations in Britain and the United States. Whereas the rural/urban differences in Africa are clearly due to lifestyle and dietary factors, the finding that hypertension is commoner in black people compared with white people may have some genetic basis. There is some evidence from salt loading studies in medical students that black Americans are more susceptible to a given salt load than white Americans, and may be more sensitive to the beneficial effects of salt restriction[53].

There is increasing evidence that fetal influences, particularly birth weight, may be a determinant of blood pressure in adult life. For example, babies who are small at birth are more likely to have higher blood pressure during adolescence and to be hypertensive as adults. Babies who are small for their age are also more likely to have metabolic abnormalities that have been associated with the later development of hypertension and cardiovascular disease, such as insulin resistance, diabetes mellitus, hyperlipidaemia, and abdominal obesity (the «Barker hypothesis»). Insulin resistance almost certainly contributes to the increased prevalence of coronary disease seen in adults of low birth weight[53].

It is possible, however, that genetic factors influence the Barker hypothesis. Mothers with above average blood pressure in pregnancy give birth to smaller babies who subsequently develop above average blood pressure themselves and eventually hypertension.

It is entirely likely that the similarity of blood pressures in mother and child are genetic and, in a modern «healthy» society, unrelated to intrauterine undernutrition[53].

Figure 8: Possible mechanisms to explain why low birth weight babies are more likely to develop hypertension in later life[53]

Source: Beevers G, Lip GYH, O'Brien E. The pathophysiology of hypertension. BMJ. 2001 Apr 14;322(7291):912-6.

In hypertensive left ventricular hypertrophy, the ventricle cannot relax normally in diastole. Thus, to produce the necessary increase in ventricular input, especially during exercise, there is an increase in left atrial pressure rather than the normal reduction in ventricular pressure, which produces a suction effect as described above. This can lead to an increase in pulmonary capillary pressure that is sufficient to induce pulmonary congestion. The rise in atrial pressure can also lead to atrial fibrillation, and in hypertrophied ventricles dependent on atrial systole the loss of atrial transport can result in a significant reduction in stroke volume and pulmonary oedema. Exercise induced subendocardial ischaemia can also produce an exaggerated» impairment of diastolic relaxation of the hypertrophied myocardium[53].

VI.1.7 DIAGNOSIS

VI.1.7.1Clinical Presentation

HTN is usually asymptomatic in children. This asymptomatic characteristic justifies why 75% to 90% of prehypertension are not diagnosed[54]. Children with mild to moderate elevation of blood pressure are asymptomatic. Only severe hypertension is symptomatic, causing headache, visual changes, epistaxis, or nausea. Retinal changes observed in adults affected by hypertension are seen in less than 50 percent of paediatric patients[55]. On following table we have the possible physical findingsindicative of secondary cause of paediatric HTN:

Table IV: Physical findings indicative of secondary cause of paediatric HTN[15]

PHYSICAL FINDINGS

POSSIBLE ETIOLOGY

Abdominal bruit

Renal artery stenosis

Abdominal mass

Polycystic kidney disease; hydonephrosis/obstructive renal lesions; neuroblastoma; wilms' tumor

Acanthosis nigricans

Type 2 diabetes

Acne

Cushing's syndrome

Adenotonsillar hypertrophy

Sleep disorder associated with hypertension

Decreased perfusion of lower extremities

Coarctation of the aorta

Diaphoresis

Pheochromocytoma

Growth retardation

Chronic kidney failure

Hirsutism

Cushing's syndrome

Joint swelling

Systemic lupus erythematosus

Malar rash

Systemic lupus erythematosus

Moon facies

Cushing's syndrome

Murmur

Coarctation of the aorta

Muscle weakness

Hyperaldosteronism Association with primary hypertension

Obesity (general) Obesity (of the face, neck, or trunk)

Cushing's syndrome

Tachycardia

Hyperthyroidism; pheochromocytoma

Thyromegaly

Neuroblastoma

Source: Gregory L, Spiotta R. Hypertension in children and adolescents. Am Fam Physician. 2006;73(9):1158-68.

VI.1.7.2 Blood Pressure Measurement in children

The preferred method for BP measurement is the auscultatory method using a mercury sphygmomanometer[19]. Other methods include:

- The Oscillometric method

- Ultrasound method

- Finger cuff method of Penaz

i. The auscultatory method [19]

Children over the age of 3years who are seen in medical care settings should have their BP measured at least once during every health care episode. Those below 3years should have their BP measured in special circumstances (Appendix IV)[19].

To confirm hypertension, the BP in children should be measured with a standard mercury sphygmomanometer, using a paediatric stethoscope(it should not be compressed by the cuff) placed over the brachial artery pulse, proximal and medial to the cubital fossa, and below the bottom edge of the cuff (i.e., about 2 cm above the cubital fossa).The use of the bell of the stethoscope may allow softer Korotkoff sounds to be heard better.

Preparation of the child for standard measurement can affect the BP level just as much as technique. Ideally, the child whose BP is to be measured should have avoided stimulant drugs or foods, have been sitting quietly for 5 minutes, and seated with his or her back supported, feet on the floor and right arm supported, cubital fossa at heart level[16,49]. The right arm is preferred in repeated measures of BP for consistency and comparison to standard tables and because of the possibility of coarctation of the aorta, which might lead to false (low) readings in the left arm[15,19]. Correct measurement of BP in children requires use of a cuff that is appropriate to the size of the child's upper right arm. The equipment necessary to measure BP in children of ages 3 through adolescence, includes child cuffs of different sizes and must also include a standard adult cuff, a large adult cuff, and a thigh cuff. The latter two cuffs may be needed for use in adolescents[19].

By convention, an appropriate cuff size is a cuff with an inflatable bladder width that is at least 40 percent of the arm circumference at a point midway between the olecranon and the acromion. For such a cuff to be optimal for an arm, the cuff bladder length should cover 80-100 percent of the circumference of the arm. Such a requirement demands that the bladder width-to-length ratio be at least 1:2[47].

Not all commercially available cuffs are manufactured with this ratio. Additionally, cuffs labelled for certain age populations (eg, infant or child cuffs) are constructed with widely disparate dimensions. Accordingly, the working group recommends that standard cuff dimensions for children be adopted (see Table V). BP measurements are overestimated to a greater degree with a cuff that is too small than they are underestimated by a cuff that is too large. If a cuff is too small, the next largest cuff should be used, even if it appears large. If the appropriate cuffs are used, the cuff-size effect is obviated[19].

SBP is determined by the onset of the «tapping» Korotkoff sounds (K1). Population data in children and risk-associated epidemiologic data in adults have established the fifth Korotkoff sound (K5), or the disappearance of Korotkoff sounds, as the definition of DBP. In some children, Korotkoff sounds can be heard to 0 mm Hg. Under these circumstances, the BP measurement should be repeated with less pressure on the head of the stethoscope. Only if the very low K5 persists should K4 (muffling of the sounds) be recorded as the DBP[19,46].

The standard device for BP measurements has been the mercury manometer. Because of its environmental toxicity, mercury has been increasingly removed from health care settings. Aneroid manometers are quite accurate when calibrated on a semi-annual basis and are recommended when mercury column devices cannot be obtained[19].

Table V: Recommended Dimensions for BP Cuff Bladders[19]

Age range

Width(cm)

Length(cm)

Maximum arm circumference(cm)

Newborn

4

8

10

Infant

6

12

15

Child

9

18

22

Small adult

10

24

26

Adult

13

30

34

Large adult

15

38

44

Thigh

20

42

52

Source:- National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004 Aug; 114(2 Suppl 4th Report):555-76.

ii. Oscillometric method[46]

Its principle is based on BP calculation from pressure oscillations detected in the arm cuff. This method determines mean BP directly from the point of maximum oscillation. Neither SBP nor DBP is measured directly, but is calculated using an algorithm based on a putative relationship between the oscillations. Then, in cases in which the oscillation is shorter than usual, as is common in children, the potential for erroneous measurement increases. If an oscillometric method is applied, the monitor should have passed the validation procedure recommended by the British Hypertension Society, the AmericanAssociation for the Advancement of Medical Instrumentationor the European Society of Hypertension International Protocol which is very difficult.Therefore, if hypertension is detected by the oscillometric methods, it must be con?rmed by the auscultatory method[19,46].

iii. Ultrasound method  [56]

Ultrasound transmitter and receiver is placed over brachial artery under blood pressure cuff. Doppler shift due to movement of blood beginning with systole up to diastole is recorded.In infants this technique is used to record systolic blood pressure. Ankle brachial index uses this technique, where in systolic pressure of brachial and posterior tibial artery is compared.

iv. Finger cuff method of Penaz [56]

Developed by Penaz, work by principle of «unloaded arterial wall». Arterial pressure is detected by photo-plethysmograph under pressure cuff. Output of plethysmograph creates a servo loop, which rapidly changes cuff pressure such that artery is maintained in open state. Oscillatory pressure in cuff are measured.Cuff can be kept for 2 hours.

VI.1.8 MANAGEMENT

VI.1.8.1 Evaluation

Once HTN has been confirmed, an extensive history and physical examination should be conducted to identify underlying causes and to detect any end organ damage[15].

History : A careful history of family history of HTN or CVD; sleep disordered breathing (snoring, obstructive sleep apnea); illicit drugs (tobacco, cocaine) and other over the counter medications should be obtained[12].

Physical examination: It should include BMI calculation; lower and upper limb BP measurement to rule out coarctation of the aorta; examination of the retina[12,15].

VI.1.8.2Laboratory and imaging tests

Laboratory and imaging tests should be conducted to screen for identifiable causes, detect comorbid conditions and evaluate end organ damage. This should proceed from simple tests that can be performed on an ambulatory setting to complex non-invasive and finally to invasive tests.

Usually findings from physical examination dictate the appropriate choice of tests(Appendix IV)[47]:

Table VI: Indicated paraclinical work-ups in case of HTN[47]

INVESTIGATION

TYPE

TEST

Laboratory

Blood

- Full blood count

-Serum creatinine

-Serum electrolytes

-Uric acid

-glucose

-Triglyceride

-Cholesterol

-Renin, aldosterone

-Lipid profile

Urine

-Dipstick

-Culture

-Sodium

-Catecholamine

Imaging

 

-Echocardiography/ Abdominal ultrasound

-Doppler studies of renal arteries

-Angiography

-CT-scan, MRI

-Polysomnography

-Fundoscopy

-24 hour Blood pressure monitoring

Source:- Lurbe E, Cifkova R, Cruickshank K, Dillon M. Management of high blood pressure in children and adolescent...?: Journal of Hypertension. J Hypertens. 2009;27:1719-42.

VI.1.8.3 Management

Managing childhood hypertension is directed at the cause of the elevated blood pressure and the alleviation of any symptoms. End-organ damage, comorbid conditions, and associated risk factors also influence decisions about therapy. Non pharmacologic and pharmacologic treatments are recommended based on the age of the child, the stage of hypertension, and response to treatment[16,44,47].

i. Non Pharmacologic Therapy

For children and adolescents with elevated BPlevel or stage 1 hypertension, therapeutic lifestyle changes are recommended[47]. These include weight control, regular exercise, a low-fat and low-sodium diet, smoking cessation, and abstinence from alcohol use[15]. Obesity increases the occurrence of hypertension threefold while favouring the development of insulin resistance, hyperlipidaemia, and salt sensitivity[57]. Significant obesity also increases the likelihood of LVH independent of blood pressure level[5,58]. Exercise has been shown to lower blood pressure in children but does not affect left ventricular function. Competitive sports are permitted for children with prehypertension, stage 1 hypertension, or controlled stage 2 hypertension in the absence of symptoms and end-organ damage[47]. Nevertheless, the NHBPEP has taken an aggressive stance on sodium restriction, recommending a sodium intake of 1,200 mg per day; a no-salt-added diet with more fresh fruits and vegetables combined with low-fat dairy and protein[19]. According to the DASH (Dietary Approaches to Stop Hypertension) food plan may be successful in lowering blood pressure in children. Increased intake of potassium and calcium also has been suggested as nutritional strategies to lower blood pressure [15]. Whatever lifestyle changes are recommended, a family-centered rather than patient oriented approach usually is more effective.

ii. Pharmacotherapy

Reasons to initiate antihypertensive medication in children and adolescents include symptomatic hypertension, end-organ damage (e.g., LVH, retinopathy, proteinuria), secondary hypertension, stage 1 hypertension that does not respond to lifestyle changes, and stage 2 hypertensionwithout a clearly modifiable factor (e.g, obesity)[44,47]. In the absence of end-organ damage or comorbid conditions, the goal is to reduce blood pressure to less than the 95th percentile for age, height, and sex. When end-organ damage or coexisting illness is present, a blood pressure goal of less than the 90th percentile is recommended[19].

Drug therapy is always an adjunct to non-pharmacologic measures. According to the NHBPEP, pharmacotherapy should follow a step-up plan, introducing one medication at a time at the lowest dose, then increasing the dose until therapeutic effects are seen, side effects are seen, or the maximal dose is reached[19,55]. Only then should a second agent, preferably one with a complementary mechanism of action, be initiated. Long-acting medication is useful in improving compliance[35]. Diuretics and beta blockers have documented safety and effectiveness in children. Preferential use of specific classes of medications for certain underlying or coexisting pathology has led to the prescribing of ACE inhibitors or ARB in children with diabetes or CKD and beta-adrenergic or calcium channel blockers for children with migraines[15]. As with any chronic health issue, medical follow-up and appropriate monitoring are keys to long-term success (Appendix IV).

A hypertensive crisis (emergency or urgency) is a life threatening condition associated with severe hypertension. Hypertensive emergency is de?ned as severe hypertension complicated with acute target organ dysfunction (mainly neurological, renal or cardiac)[45]. Hypertensive urgency is de?ned as severe hypertension without acute target organ dysfunction. Children with hypertensive emergencies should be treated in an intensive care unit to ensure monitoring and support of the vital organs.The treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to the target organs, but not at a rate likely to cause hypo perfusion of vital organs by an excessively rapid reduction of BP (mainly cerebral hypo perfusion with neurological sequelae) [47]. In such situations, the BP should be reduced by more than 25% of the planned reduction over the first 8 hours, with the remainder of the planned reduction over the next 12 to 24 hours. The ultimate short-term BP goal in such patients should generally be around the 95th percentile. Appendix IVlists suggested doses for oral and intravenous antihypertensive medications that may treat patients with acute severe HTN[44].

Figure 9: Management algorithm[19]

Rx indicates prescription; Q, every; †, diet modification and physical activity; ‡,especially if younger, very high BP, little or no family history, diabetic, or other risk factors.

Source:- National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004 Aug; 114(2 Suppl 4th Report):555-76.

VI.1.9COMPLICATIONS

i. Cardiac complications

A pulmonary oedema with asystolia can brutally decompensate a moderate left ventricular overload in a newborn. It appears sometimes that the blood could be within normal limits or low controlled, rising after a reduction of the heart failure[43]. Signs and symptoms of target organ damage are present only in the late stages of the disease. Left ventricular hypertrophy (LVH) is the most common target organ abnormality found in childhood[58]. LVH is present in 34 to 38% of children with mild, untreated hypertension[58,59]. Paediatric patients with established LVH is an indicator to initiate or intensify antihypertensive therapy[41,58]

ii. Vascular complications

The vascular repercussion is potentially severe due to the risk of vascular rupture: intracerebral rupture in case of cerebral arteriovenous malformations, retinal haemorrhage (dramatic functionally) oraortic dissecting aneurysm. There are otherwise certain vasomotor phenomena which can aggravate a cerebral or renal ischemia[60].

iii. Neurologic complications

Seizures can be rebel to anticonvulsants if HTN isn'tcontrolled. A cerebral haemorrhage sometimes massive, could be associated to hemiplegia or a cortical blindness, an intra-ventricular haemorrhage in the premature newborn, and a cerebral oedema responsible for an intracranial hypertension complicated in severe cases by a hypertensive encephalopathy[43].

iv. Renal complications

Every severe HTN leads to lesions of nephro-angiosclerosis: necrosis of the afferent arteriole, glomerular hyalinisation. These lesions could lead to a kidney failure, prone to regression, at least a little, after control of HTN. Exceptionally in children, certain malignant HTN with nephro-angiosclerosis lead to a haemolytic and uremic syndrome with a rapidly irreversible kidney failure[60].

v. Ocular complications

They are quite rare but severe: finite blindness following retinal haemorrhage,retinal detachment or optic atrophy secondary to a papillary oedema. The severity of lesions seen on fundoscopy is not linked to the oldness of the HTN nor the existence of any other visceral anomaly[61].

VI.2 REVIEW OF PUBLICATIONS ONHYPERTENSION IN CHILDREN

Several studies have been carried out worldwide to determine blood pressure profile and their risk factors in children.

v Out of Africa

· In 2004, Sorof et al screened 5102 children in the U.S.A aged 13-17years in 4ethnic distributions(white 44%,Hispanic 25%, African American 22%, and Asian 7%). The prevalence of HTN after the first, second and third screenings was 19.4%, 9.5%, and 4.5%.Overall, overweight prevalence was significantly associated, with significant variations between the ethnic distributions.They however, noted that the ethnic differences in the prevalence of hypertension were not significant after controlling for overweight[62].

· In 2004, Moura et al used the cross sectional methodology on 1253 children aged 7-17years in Brazil and observed a prevalence of HTN of 9.4%. They noticed blood pressure was significantly associated with overweight and obesity. However, no statistical differences were observed between males and females with regards to the prevalence of elevated blood pressure [63].

· In the U.S.A, Urrutia-Rojas et al in 2006 carried out a school based cross sectional study to determine the prevalence and associated factors of HTN on 1066 children aged 8-13years. They noted a 20.6% prevalence of HTN and HTN was significantlyassociated with overweight and obesity as well as African Americans which were more likely to have HTN than Caucasians[8].

· In 2010, Sharma et al in India, carried out a cross sectional study and screened 1085 school children aged 11-17years for HTN and found a prevalence of 5.9% HTN and 12.3% Prehypertension after 2 evaluations. In their study, prevalence of HTN in obese children was 46.5% and 17% in non-obese; urban and rural children had comparable rate of elevated BP-[64].

· In China, Xi Lu et al in 2013, carried out a school-based cross sectional study on 78,114 children and adolescents. In their study, both SBP and DBP were significantly increased in overweight and obese groups; and the prevalence of high SBP, DBP and hypertension(ranges from 8 to 26%) were markedly higher among overweight and obese children than normal weight groups[46].

· Flavio et al in 2016 in Brazil, conducted an observational cross sectional study on a sample of 157 students from the city of Petropolis aged from 10 to 19 selected randomly. In their study, the prevalence of HTN was 10.8% and there was a significant association with overweight and obesity as well as with the pressure of family history of hypertension[65].

· Nihaz et al in 2016 in India, carried out a cross sectional study on 1610 school children aged 5-10years from 6 schools of rural urban regions; and found a prevalence of HTN of 4.5% and pre-HTN of 5.8%. In their study, urban school children with hypertension were 7.52% against rural were 1-2%, pre hypertension in urban school children were 9.4% ,rural 1.84% Hypertension in males were 4.31% and in females were 4.65%. They also noted, a strong association between childhood obesity, family history of diabetes mellitus, ischemic heart disease and cerebrovascular accident; and childhoodhypertension[66].

· In 2017, Yide Yang et al in China, carriedout a national cross sectional survey on 62, 168 participants aged 6- 17years with complete data of body weight, height, and blood pressure; and found a prevalence of HTN of 10.2% and 8.9% for boys and girls, respectively. In their study, isolated systolic high blood pressure is the dominant high blood pressure subtype among Chinese boys aged 6-17 years and girls aged 12-17 years, while isolated diastolic high blood pressure was the most common high blood pressure subtype in girls aged 6-11 years; and boys with adiposity showed a higher risk of high blood pressure than their female counterpart[67].

· Espinosa et al in 2017 in Spain conducted a cross sectional study including a sample of 1,604 schoolchildren aged 4- 6 years belonging to 21schools from the provinces of Ciudad Real and Cuenca, Spain. The results show estimates of prevalence of HTN and prehypertension being 18.2% and 12.3% respectively, and was significantly associated to high levels of adiposity-[68].

v In Africa

· In South Africa in 2005, Monyeki et al carried out a longitudinal study to assess association of fat patterning with blood pressure in children aged 6-13years. They noted that the prevalence of HTN ranged from 1 to 5.8% and 3.1 to 11.4% for girls. A significant association between high diastolic BP and high BMI was noted, while children with low BMIs were less likely to be hypertensive[38].

· Harrabi et al in 2006, carried out a cross sectional study on 1559 children aged 5-15years in Tunisia. They noted 9.6% prevalence of HTN with no significant difference in prevalence between boys (9.2%) and girls (9.9%). Boys had higher mean SBP compared to girls. In both boys and girls, systolic pressure had a highly significant positive correlation with the height, weight, and triglyceride concentration-'''''''''''''''-[11].

· In Nigeria, Okoh et al in 2012, conducted a cross sectional study to evaluate the prevalence and severity of HTN in 1302 school children aged 6-12years. The prevalence of HTN was 4.7% and prehypertension was 4.6%. Prevalence of HTN was higher on females and a high BMI was significantly associated with HTN[23].

· In Congo, Ellenga et al in 2014 conducted a cross sectional study to determine the prevalence and associated risk factors of pre-HTN and HTN in school children at Brazzaville in Congo, where they screened 603 children and noted a prevalence of 10.1% during the first screening and 3.3% in the second screening for HTN;and 20.7% for prehypertension.Obesity and overweight as well the high economic level are greatly associated with HTN in this population'-[6].

· In 2015, Juliana et al in South Africa, conducted a study which utilized data from the Birth to Twenty cohort, which comprised a sample of 3273 children born in Soweto, Johannesburg in 1990.In this study, the overall point prevalence ranged from 9.2 to 16.4% for prehypertension and 8.4 to 24.4% for hypertension which showed a high prevalence of HTN which tracks from early childhood into adolescence           - - [69].

· In 2017, Umar et al in Nigeria, carried out a multistage sampling technique which was used to select 2000 pupils from 66 primary schools in Kano aged 6-14years. This study showed a prevalence of HTN of 3%, higher in females as compared to males with a positive significant correlation with the body mass index-[70].

v In Cameroon

· Fotso in 2012, conducted a cross sectional study on 628 school children aged 7-19years in Yaounde. She noted that BP was high in 1 out of every 6 children with a prevalence of HTN of 2.2%. The mean SBP and DBP were 112#177;14mmHg and 69.7#177;10mmHg respectively'''''''''''''''''''''''`'''''''''''''[25].

· In 2014, Bissohong carried out a prospective-descriptive study from Sept 2014 to May 2015 on 769 school children aged 4-18years in Bertoua. The prevalence of HTN was 2.9% and was more prevalent in males than in females. Mean SBP and DBP were 106.8mmHg and 68.4mmHg respectively'''''''''''''''''''''''''''''''[24].

· Samain in 2015,carried out a community-based cross sectional study on 1313 primary school children aged 5-15years in Buea. The prevalence of hypertension was 3.2% and that of prehypertension was 7.6%. 3.5% of males and 2.9% of females were hypertensive. Hypertension was significantly associated with obesity. There was no significant association between hypertension and family history of hypertension and hypertension was of systolic predominance[26].

CHAPTER Vii: MATERIALS AND METHODS

VII.1 STUDY DESIGN

The study is a school-based cross-sectional analytic study.

VII.2 STUDY AREA

The study was carried out in public and private primary schools in the Mbankomo subdivision, in the Centre Region of Cameroon. Cameroon is divided into 10regions: Far North, North, Adamawa, Centre, Littoral, East, West, South, South West and North West Regions. The Centre which is our region of interest has Yaounde as capital. Mefou and Akono whichis one of its divisions covers an area of 1,329km2 and had a population of 57,051inhabitants in 2001(according to the 2004 Cameroon statistical annual). It is made of 4subdivions: Akono, Bikok, Ngoumou and Mbankomo, with the latter being our area of interest. Mbankomo has a population of 20,305inhabitants and a surface area of 1,300 km2.

The Mbankomo subdivision has a total of 71 primary schools(31 public schools and 40 private schools) with a total of 10,308 pupils in all her primary schools: 6,006 in public schools and 4,302 in private schools. A sample was thereby derived from these schools using a cluster sampling method.

VII.3 STUDY PERIOD

The study was carried out over a period of six months (21thNovember 2017 - 22thMay 2018).

VII.3.1 STUDY POPULATION

a) Target population

Primary school children inMbankomo subdivision found in theMefou and Akono division, Centre Region.

b) Sample Size Calculation

The sample size was calculated using the Cochran's formula for sample size for one proportion of a finite population. For that we used[71];

Sample size(n) =

Where;

n= Minimum sample size required

p= Prevalence of hypertension in primary school children.

d= Error margin of 1-5%

(Z1-á/2)2 =95% confidence interval (value type=1.96)

Considering;

p= Prevalence of hypertension in primary school children of 3.2% in the study of Samain Nkendo (in primary school children in Buea) [26].

d= 2% error margin

Arithmetic calculation;

N=298pupils

Considering;

Imponderables (filling errors, absences..etc) n'=10% n= 0.1 x 298= 29.8

Total Minimum sample sizeN= 298 + 30 = 328 pupils

Using this approach, the minimum sample size was 298 pupils. Considering 10% missing data, 328 pupils were initially targeted.

c) Sampling Method

A two staged cluster sampling technique wasused to select participants.

The first stage consisted of conveniently selecting 13 primary schools or clusters (18% of 71 primary schools in the study area) by probability proportionate to size.

We used this method because the subdivision does not have the same number of primary schools in the rural and semi-urban settings. It was therefore, appropriate to consider the use of a random selection process where the probability of inclusion of each cluster in the sample, tend to be proportional to the size of the cluster.

This was done by listing all the schools (both public and private) in the 2 settings(rural and semi urban) irrespective of the method used for ordering them and, we sampled systematically as follows: The first school was selected randomly by balloting and thereafter every 7th school (Kth = 71/13) was selected until 13primary schools were obtained, as seen below:

Table VII: Selected primary schools for the study

School Setting

Type of school

Name of school

Rural

Public(8)

Ebeba Government primary school(266)

Zouatoupsi Government primary school (133)

Angon II Government primary school (79)

Nkolngok Government primary school (287)

Nomayos Government primary school (197)

Binguela Government primary school (179)

Eloumden II Government primary school (69)

Oveng Government primary school (187)

Private(0)

 

Semi urban

Public(2)

Mbalngong Government Bilingual primary school (358)

Mbankomo Government Bilingual primary school (501)

Private(3)

Parcours Des Doués Private Bilingual primary school (154)

Prodige Plus Private Bilingual primary school (111)

Pfister Private Bilingual primary school (23)

In the second stage, our clusters were the 13 selected primary schools. Since the number of pupils enrolled in each of the 13 schools selected above were different, we used probability proportional to size to select participants by randomly selecting (13%) pupils in each class enrolled in each of the schools. This was done so that the final sample will proportionally represent each of the classes, each primary school, as well as each school setting.

Minimal sample size + expected loss (328) x 100

Total No of pupils enrolled in the 11 selected schools

(2,544)

Proportion of pupils in each school to be included in the study

(13%)

=

=

This was done as follows: The study was explained to the pupils in each class (class 1-6) and verbal assent obtained. Thereafter a minimum of 13%of the pupils in that class were selected by balloting.

d) Selection criteria

Inclusion Criteria

· Children enrolled in a primary school.

· Children present in school on days of recruitment.

· Children with signed consent form by parents or tutors and who acceptedto participate in the study.

Exclusion Criteria

· Any child who because of a disability not permitting weight, height, or blood pressure takings as recommended by the WHO.

· Children taking medication known to lower blood pressure in whom a diagnosis of HTN has not been made.

VII.4 DATA COLLECTION

The self-administered section of the questionnaire was filled by parents/guardians while the interviewer-administered section was filled by the investigator.

The data collected consisted of:

- The socio-demographic characteristics of the child (age, sex,type of school, class,school setting, milieu, profession and telephone number of legal tutor)

- Socio economic status[which is an adapted classification from therevisedKuppuswamy's socio-economic status scale- January 2015-[72](see APPENDIX IV)]where the projected family income was estimated from the Gross National Income (GNI) per capital.

- Lifestyle(feeding habits, physical activities and sedentarity)

- Medical record of the child (birth weight,term, chronic illness)

- Medical record of Parents and other family members(family history of hypertension, obesity or overweight,diabetes)

- Anthropometric measurements(height, weight, BMI)

- Blood pressure measurement

- Urine dipstick test

VII.5 STUDY PROCEDURE

Administrative and ethical approvals

A prior ethical clearance from the Ethical Committee of the Faculty of Medicine and Biomedical Sciences of the University of Yaounde I was obtained, as well as authorizations from the Divisional Delegation of Basic Education at Ngoumou and the Sub Divisional Inspectorate of Basic Education at Mbankomo. An informed note was addressed to the respective school authorities to the chosen schools in order to obtain their authorizations.

A meeting was organized to prepare the investigators made up of; a student nurse and a 7th year student to plan data collection, as well as training sessions for anthropometric measurements.

Approach of Participants

The study involvedprimary school children and as such legally could not give consent. After explanation of the study in each class, a verbal and a written signed assent were obtainedfrom parents/guardians before inclusion in the study. Among the pupils who accepted to be part of the study, participants were selected by simple random sampling. Each of them was given a consent form and a questionnaire (English or French) to take home for their parents/guardian to fill and sign if they accepted that their children should participate in the study. Information was collected only from those who returned with signed consent form, correctly filled questionnaire and who also gave verbal assent.

Blood Pressure Measurement

Blood pressure was measured and classified according to the AAP (American Academy of Pediatrics) recommendations [44]. Before blood pressure measurements, pupils were familiarized to the instrument and the nature of the procedure was explained.

Blood pressure was measured in the sitting position on the right arm using the auscultatory method with a pediatric stethoscope, and a standard aneroid sphygmomanometer with appropriate cuff size covering at least 2/3rd (80%) of the upper arm and encircling it completely (at least 40%). The child's right arm was supported at the level of the heart during measurements. This was the preferred arm because of consistency and comparison to standard tables and also because of the probability of decreased BP on the left arm caused by coarctation of the aorta.

The stethoscope was placed lightly over the brachial artery(if pressed too firmly against the artery, it might cause turbulence and the disappearance of sound, thus artificially reducing the diastolic pressure). The cuff was inflated to a pressure of 30mmHg above the level at which the radial pulse was no longer palpable. While slowly deflating the cuff (approximately 2-3mmHg per heartbeat), the Korotkoff phase I was listened while watching the blood pressure gauge. Korotkoff phase I was identified by the first pulse auscultated. The measurement was then recorded from the sphygmomanometer at which the sound first appeared; representing the participant's systolic blood pressure. While watching the sphygmomanometer, the cuff was continuously slowly deflated till an abrupt soft, indistinct, muffling sound was heard (Korotkoff phase IV). This sound was then continuously listened until it disappeared completely (Korotkoff phase V) and recorded; this represented the participant's diastolic blood pressure. The cuff was completely deflated and the child was allowed to rest.

For each participant, BP was measured twice in the same visit with a minimum of 30 seconds rest interval and the mean BP calculated. We waited for another 1-2minutes and repeated the blood pressure measurement procedure on the participant's opposite arm and if a measurement discrepancy existed between the 2arms, then arm the highest measurement was noted. BP readings were taken to the nearest 2mmhg. BP readings were classified according to the recommendations of AAP as follows:

· Elevated BP if SBP and/or DBP were between 90th and 95th percentile for age, height and sex or if SBP>120mmhg or DBP>80mmhg.

· Hypertensive if SBP and/or DBP were equal to or greater than the 95th percentile for height, age and sex.

Participants who were hypertensive on the first visit were rechecked (had a repeated BP measurement) 2 times at intervals of 1 week to ensure persistent hypertension.The pupils diagnosed of hypertension underwent a urine dipstick test for proteinuria.

Eachhypertensive pupil was referred to the Mbankomo district hospital and a Pediatric Cardiologist for management and follow-up. At the end of the study, a list of all the hypertensive pupils diagnosed and their respective schools were sent to the Delegate of Basic Educationof the Mefou and Akono division in Ngoumou as well as the findings from our study.

Anthropometric Measurements

Participants were weighed barefoot, standing still, without support and wearing light clothes(removed shoes and heavy clothing, such as sweaters) using a manual weighing scale and recorded in the nearest 0.1kg.

Height was measured using a wooden stadiometer calibrated in centimeters (cm) and recorded in the nearest 0.1cm. Each participant stood erect with no shoes on and with the occiput, shoulder, buttocks and calf touching the vertical position of the stadiometer.

The readings were recorded on a corresponding data collection sheet of each participant before going to the next. Weight and height were used to determine BMI. Pupils were categorized by age and sex using WHO BMI growth tables and charts(Appendix III).Pupils' heights were categorized to height percentile using WHO height for age and sex standard tables and charts (Appendix III).

Data was collected on a daily basis and recorded in a computer progressively.

Figure 10: Measurement of the height[73]

Source :The Mother and Child Health and Education Trust. Taking the Weight-for-Height/Length - Anthropometric Measurements Techniques - Diagnosis of Acute Malnutrition - Mother, Infant and Young Child Nutrition & Malnutrition - Feeding practices including micronutrient deficiencies prevention, control of wasting, stunting and underweight [Internet]. 2017 [Cited 29 October 2017]. Available from: http://motherchildnutrition.org/malnutrition-management/integrated-management/taking-the-weight-for-height-length.html

VII.6 MATERIALS

The materials for the study included:

· A data entry form with two sections (section one for the parents' and child's medical records and section two for blood pressure and anthropometric parameters).

· A paediatric stethoscope and paediatric aneroid sphygmomanometer (GIMA*) with various cuff sizes appropriate for mid upper arm circumference (< 8cm, 8-14cm, 14-21cm, >21cm).

· A measuring scale (Seca*).

· A wooden portable stadiometer (UNICEF) (calibrated in centimeters).

· A laptop

· Microsoft® Office Excel 2013, SPSS standard version(20.0) for windows, WHO Anthro Plus version 1.0.4and Epi-infoTM version 3.5.4 software for data analysis and Microsoft® Office Word 2013 as the input software

· A 4 GB flash disk

· Office equipments

VII.7 HUMAN RESOURCES

· Director: Professor OBAMA Marie Therese

· Co-directors:Associate Professor CHELO David,Associate Professor MAH Evelyn Mungyeh

· Investigator:CHIABI Edmond Ngong

· Collaborators: Trained personnel

· A statistician

VII.8 DATA ANALYSIS

The investigator was to note the collected data of each patient on the pre-established work sheet(Appendix I) and typed it down in Epi info 3.5.4, by making a view. Then, it was analysed using the Epi info 3.5.4and anthropometric data was analysed using WHO Anthro version 3.2.2. The graphs were produced with the use of Microsoft Excel 2013.

The quantitative variables were described using mean and standard deviation while the qualitative variables were described using frequencies and proportions.

Analysis were carried out to assess associations between each variable.Correlation between quantitative variables was described using Pearson's correlation coefficient (r).

Associations between qualitative variables weredescribed by comparing proportions using Chi-Square test(when an expected value is >5) and Fisher's exact test (when an expected value is <5). The force of association wasevaluated using the Odd's ratio and statistical significance was considered at P-value < 0.05.

VII.9 DATA MANAGEMENT

§ Definition of Variables

Ø Quantitative variables: Age, Number of meals per day, fruit and vegetable consumption per week, sport practice duration per week, weight, height, level of education of legal tutor, birth weight.

· Television and/or computer :<1hour,1-2hours, >2hours

· Sleeping time :<6hours, 6-8hours, >8hours

· Blood pressure: The American form of blood pressure presentation was adopted as follows:

- Normal blood pressure: BP< 90th percentile for age, gender and height.

- Prehypertension: BP =90th and <95th percentile

- Hypertension: BP =95th percentile

· BMI (according to WHO classification for assessment of nutritional status)'-[6]

- Underweight: BMI <5th percentile

- Normal weight: BMI =5th and <85th percentile

- Overweight: BMI =85th and <95th percentile

- Obesity: BMI =95th percentile

· Proteinuria

- Trace (<30mg/dl)

- +1 (=30 - <100mg/dl)

- +2(=100-<300mg/dl)

- +3 (=300 - <1000mg/dl)

- +4 (=1000mg/dl)

· Adapted socio-economic status scale(Part 1)

- Monthly family income(FCFA) : =15,072 ; 15,073 - 45,217 ; 45,218 - 75,363 ; 75,364-113,045 ; 113,046 - 150,727 ; 150,728 - 301,454 ; =301,455

- Class : Low (<5), Middle (5-10), High(>10)

Ø Qualitative variables

· Gender: Male and Female

· Type of school: public and private

· School setting: rural and semi urban

· Profession of legal guardian: Student, civil servant, private worker, informal, unemployed.

· Adding salt at table: Yes or No

· Fruit juice consumption: Occasionally and Regularly

· Means of locomotion: by foot, by vehicle

· School sports: Yes or No

· Extracurricular sports: Yes or No

· Term: At term and premature

· Family history of HTN/diabetes/Overweight or obesity: Yes or No

· Urine dipstick test-blood: Yes or No

· Adapted socio-economic status scale(Part 2)

- Profession of legal tutor :Skilled worker, Unskilled worker, Unemployed

- Level of education of legal tutor:Higher education, Secondary (2nd cycle), Secondary (1st cycle), Primary, Illiterate

CHAPTER VIII: RESULTS

VIII.1 STUDY FLOW PROFILE

For this study, 1,754 consent forms and questionnaires were distributed to all the pupils enrolled in the 13 selected primary schools (private and public) in Mbankomo subdivision.422 (34%) pupils were excluded because of absence, poorly filled questionnaires and loss of follow up. Only 822 (66%) pupils were finally included in the study. The figure below represents the flow diagram of the sample population.

1,754 consent forms and work sheets distributed

510(29%) pupils non-included

510 (29%) parents did not give their consent

1244(71%) consent given

199 (16%) poorlyfilledquestionnaires

186 (15%) pupils who failed to return form

422(34%) pupilsexcluded

37 (3%) pupils who were absent from school

822(66%) pupilsincluded in the study

Figure 11: Flow diagram of the study

VIII.2 SOCIO-DEMOGRAPHIC CHARACTERISTICS OF STUDY POPULATION

VIII.2.1 Pupil

VIII.2.1.iGender

Table VIII: Distribution of pupils by gender

Gender

Frequency(n)

Percentage(%)

Male

353

42.9

Female

469

57.1

Total

822

100

Of the 822 pupils recruited, 469 (57.1%) were femalesand353 (42.9%) were males, giving a sex ratio of 1.3.

VIII.2.1.ii Age

Table IX: Distribution of pupils by age

Age(in years)

Frequency(n)

Percentage (%)

[5-8[

268

32.6

[8-11[

338

41.1

[11-14[

193

23.5

[14-18[

23

2.8

Total

822

100

The mean age was 9 #177; 2.5 years (with extremes from 5 to 17years). The most represented age range was 8-10 years (41.1%), and was followed by those aged 5-7 years (32.6%).

VIII.2.1.iii Type of school and school setting

Table X: Distribution of pupils by type of school and school setting

 

Frequency(n)

Percentage(%)

Type of school

Public

681

82.8

Private

141

17.2

School setting

Rural

356

43.3

Semi urban

466

56.7

In this study, 681 (82.8%) pupils were from public schools and 141 (17.2%) pupils were from private schools.

A total of 466 (56.7%) pupils were from a semi urban setting and 356 (43.3%) pupils were from a rural setting.

VIII.2.1.iv Class

Table XI: Distribution of pupils by class

Class

Frequency(n)

Percentage(%)

Class 1/Sil

126

15.3

Class 2/ CP

114

13.9

Class3/ CE1

125

15.2

Class4/ CE2

121

14.7

Class5/ CM1

150

18.3

Class6/ CM2

186

22.6

Total

822

100

The most represented classes were class 6 and class 5 in respectively 22.6% and 18.2%.

VIII.2.2 Legal tutors

VIII.2.2.i Profession of legal tutors

Table XII: Distribution by profession of legal tutor

Profession of legal tutor

Frequency(n)

Percentage(%)

Non liberal*

139

16.9

Liberal**

409

49.8

Unemployed

274

33.3

Total

822

100

*Civil servants

**Lawyers, traders, technicians, private sector, student, retired

Most of the legal tutors were on liberal professions (49.8%).

VIII.2.2.i Socio-economic status

Table XIII: Distribution by socio-economic status (N=96)

Socio-economic status

Frequency(n)

Percentage(%)

Low

8

8.3

Middle

84

87.5

High

4

4.2

Total

96

100

Out of the 822 legal tutors who took part in the study, only 96 correctly filled the section of the socio-economic status and 84 (87.5%) homes had the middle socio- economic status.

VIII.3 ANTHROPOMETRIC PARAMETERS OF STUDY POPULATION

VIII.3.1 BMI classification of the study population

Table XIV: BMI classification ofthe study subjects

BMI

Frequency (n)

Percentage (%)

Normal weight

757

92.1

Underweight

5

0.6

Overweight

55

6.7

Obesity

5

0.6

Total

822

100.0

Out of the 822 pupils enrolled, 757 (92.1%) pupils had a normal BMI; 55 (6.7%) pupils were overweight; and 5 (0.6%) pupils were obese.

VIII.3.2 Excess weight and age

Table XV: Distribution of overweight/obesity by age range (N=60)

Age(years)\BMI

Overweight n(%)

Obesity n(%)

Total n(%)

[5-8[

25 (96.2)

1 (3.8)

26 (100)

[8-11[

17 (89.5)

2 (10.5)

19 (100)

[11-14[

12 (85.7)

2 (14.3)

14 (100)

[14-18[

1 (100)

0 (0)

1 (100)

Out of the 60 pupils who were overweight/obese, 45 were highly represented in the age range of 5-10 years.

VIII.3.3 Excess weight and gender

Table XVI: Distribution of overweight/obesity by gender (N=60)

Gender\BMI

Overweight n(%)

Obesityn(%)

Total n(%)

Male

23 (100)

0 (0)

23 (100)

Female

32 (86.5)

5 (13.5)

37 (100)

Out of the 60 pupils who had overweight/obesity, 37 were female out of which 5 were obese.

VIII.4 PREVALENCE OF ELEVATED BP AND HYPERTENSION

VIII.4.1Prevalence of Elevated BP and Hypertension based on the AAP

Figure 12: Prevalence of hypertension and Elevated BP on all 3 screenings

On the first screening, 55 (6.6%) pupils had an elevated BP level and 67 (8.0%) pupils were found to be hypertensive. On the second screening, one week after the first screening, 60 (7.3%) pupils had an elevated BP level and 29 (3.5%) were hypertensive. On the third screening, one week after the second screening, 67 (8.1%)pupils had an elevated BP level and 13 (1.6%) hypertensive.

VIII.4.2 Prevalence of Elevated BP and hypertension at third screening

Table XVII: Prevalence of Elevated BP and HTN(at third screening) (N=822)

Blood pressure status

Frequency(n)

Percentage(%)

Normal

742

90.3

Elevated BP

67

8.1

Hypertension

13

1.6

Stage 1

12

1.5

Stage 2

1

0.1

Out of the 13(1.6%) hypertensive pupils, 12 (1.5%) had stage one hypertension and 1 (0.1%) had stage two hypertension.

VIII.4.3 Prevalence of Elevated BP and hypertension with respect to systolic blood pressure (SBP) and diastolic blood pressure(DBP)

Table XVIII: Prevalence of elevated SBP and DBP

Blood pressurestatus

SBP n (%)

DBP n (%)

SBP +DBPn (%)

Normal

741 (90.1)

792 (96.4)

701

Elevated BP

68 (8.3)

26 (3.2)

3

Hypertension

13 (1.6)

4 (0.4)

8

The prevalence of elevated BP and HTN was predominantlysystolic in 68 (1.6%) pupils and in 13 (1.6%) pupils respectively.

VIII.4.4Distribution of Elevated BP and hypertension with respect to socio-demographic characteristics and anthropometric parameters

Table XIX: Prevalence of Elevated BP and hypertension with respect socio-demographic characteristics and anthropometric parameters

Characteristics

Normal n(%)

Elevated BP n(%)

Hypertension n(%)

Total n(%)

 

Age(years)

[5-8[

258(96.2)

10(3.7)

0(0)

268(100)

 

[8-11[

317(93.7)

18(5.3)

3(0.8)

338(100)

[11-14[

155(80.3)

31(16.0)

7(3.6)

193(100)

[14-18[

12(52.1)

8(34.7)

3(13.0)

23(100)

Gender

Male

323(91.5)

27(7.6)

3(0.8)

353(100)

 

Female

419(89.3)

40(8.5)

10(2.1)

469(100)

Type of school

Public

615(90.3)

54(7.9)

12(1.7)

681(100)

 

Private

127(90.0)

13(9.2)

1(0.7)

141(100)

School setting

Rural

321(90.1)

30(8.4)

5(1.4)

356(100)

 

Semi urban

421(90.3)

37(7.9)

8(1.7)

466(100)

BMI Status

Underweight

5(100)

0(0)

0(0)

5(100)

 

Normal weight

695(91.8)

55(7.2)

7(0.9)

757(100)

Overweight

41(74.5)

9(16.3)

5(9.0)

55(100)

Obesity

1(20)

3(60)

1(20)

5(100)

Hypertension was predominant in the age range 14-17 years in 13.0%, in females in 2.1%, in public schools in 1.7%, in semi urban in 1.7%, and in obese in 20%.

VIII.4.5Correlation of systolic and diastolic blood pressure withanthropometric parameters

Table XX: Correlation between blood pressure and, age and BMI

Variables

SBP

DBP

 

Correlation

coefficient (r)

p-value

Correlation

coefficient (r)

p-value

Age

0.17**

0.000

0.07**

0.000

BMI

0.18**

0.000

0.11**

0.000

p-value from Pearson's correlation test

**Correlation is significant at the 0.01 level (2 tailed)

SBP(r=0.17; p=0.000) and DBP (r=0.07; p=0.000) statistically increased with age (figures13 and 14 respectively).

Also, the SBP (r=0.18; p=0.000) and DBP (r=0.11; p=0.000) statistically increased withBMI (figures 14 and 15 respectively).

Figure 13 : Correlation between SBP and age

Scattered plot diagram showing a positive correlation of SBP and age (r=0.17; p=0.000).

Figure 14: Correlation between DBP and age

Scattered plot diagram showing a positive correlation of DBP with age (r=0.07; p=0.000).

Figure 15: Correlation between SBP and BMI

Scattered plot diagram showing a positive correlation of SBP with BMI (r=0.18; p=0.000)

Figure 16: Correlation between DBP and BMI

Scattered plot diagram showing a positive correlation of SBP with BMI (r=0.11; p=0.000).

VIII.5URINE

VIII.5.1 Proteinuria

Out of the 13 hypertensive pupils who underwent the dipstick urine test for proteinuria, 12 (92.3%) pupils had protein traces in urine and 1 (7.7%) pupil had a high protein count in urine.

VIII.5.2 Blood

Out of the 13 hypertensive pupils who underwent the dipstick urine test for blood, none had blood found in the urine.

VIII.6 BIVARIATE ANALYSIS OF FACTORS ASSOCIATED TO HYPERTENSION

VIII.6.1Socio-demographic status

Table XXI: Socio-demographic status and hypertension

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR (CI 95%)

P-value*

Age(years)

=10

2 (0.4)

488 (99.6)

490

 
 

>10

11 (3.3)

321 (96.7)

332

8.36 (2.06-55.73)

0.000

Gender

Female

10 (2.1)

459 (97.9)

469

2.54 (0.73-11.54)

0.120

Male

3 (0.8)

350 (99.2)

353

 
 

School type

Public

5 (1.4)

351 (98.6)

356

0.82 (0.24-2.55)

0.480

Private

8 (1.7)

458 (98.3)

466

 
 

School setting

Rural

5 (1.4)

351 (98.6)

356

0.82 (0.24-2.55)

0.480

Semi urban

8 (1.7)

458 (98.3)

466

 
 

*p-value from Chi-square test

Among the socio demographic characteristics of the pupils analysed, only the age (above10 years old) was a significantly associated factor of hypertension (OR=8.36; CI95=2.06-55.73; p=0.000). Gender had some association although not significant (p=0.120).

VIII.6.2Socio-economic status

Table XXII: Socio-economic status (N=96) and HTN

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR (CI 95%)

P-value*

Low

0 (0)

8 (100)

8

0 (0-30.62)

0.880

Middle/High

2 (2.3)

86 (97.7)

88

 
 

*p-value from Chi-square test

Out of 96 legal tutors who filled this section, the economic status was not an associated factor of hypertension (OR=0; CI95=0-30.62; p=0.880).

VIII.6.3Feeding habits

Table XXIII:Feeding habits and HTN

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR (CI 95%)

P-value*

Salting

Yes

5 (2.4)

203 (97.6)

208

1.87 (0.55-5.83)

0.210

No

8 (1.3)

606 (98.7)

614

 
 

Fruit consumption

0

0 (0)

111 (100)

111

0 (0-1.65)

0.150

=1

13 (1.8)

698 (98.2)

711

 
 

Vegetable consumption

0

0 (0)

90 (100)

90

0 (0-2.11)

0.220

=1

13 (1.8)

719 (98.2)

732

 
 

Water consumption

=1liter Yes

10 (2.3)

428 (97.7)

438

2.97 (0.85-13.47)

0.070

No

3 (0.8)

381 (99.2)

384

 
 

>1liter Yes

3 (0.8)

366 (99.2)

369

0.36 (0.08-1.26)

0.090

No

10 (2.2)

443 (97.8)

453

 
 

Sweetened soft drinks (brewed juice) consumption

Occasionally**

6 (1)

572 (99)

578

0.36 (0.11-1.11)

0.060

Regularly***

7 (2.9)

237 (97.1)

244

 
 

*p-value from Chi-square test

**<3days/week

*** =3days/week

Adding salt carried twice the risk but the association was not significant (p=0.210) same as not drinking enough water carried 3times more risk (p=0.070).

VIII.6.4Physical exercise and sedentarity

Table XXIV: Physical exercise and sedentarity and HTN

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR(CI95%)

P-value*

Means of locomotion

On foot

10 (1.3)

746 (98.7)

756

 
 

By vehicle

3 (4.5)

63 (95.5)

66

3.55 (0.77-12.58)

0.080

Television/video games

None Yes

1 (2.1)

46 (97.9)

47

1.38 (0.06-8.25)

0.540

No

12 (1.5)

763 (98.5)

775

 
 

Watched =2hours

/played

9 (1.6)

548 (98.4)

557

1.07 (0.33-4.04)

0.590

>2hours

3 (1.4)

215 (98.6)

218

Sports

Yes

11 (1.5)

732 (98.5)

743

0.58 (0.14-3.91)

0.360

No

2 (2.5)

77 (97.5)

79

 
 

Sleeping period

=8hours

10 (1.9)

506 (98.1)

516

2 (0.57-9.07)

0.220

>8hours

3 (1)

301 (99)

304

 
 

*p-value from Chi-square test

Of all the elements of physical exercise and sedentarity analysed, sports wasn't protective against HTN although not significant (p=0.360), while moving in a car and sleeping for =8hours carry relative risks although not significant (p=0.080 and p=0.220, respectively).

VIII.6.5Past history

Table XXV: Past history and HTN

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR (CI 95%)

P-value*

Birth weight(grams)

<2500

3 (13)

20 (87)

23

11.84 (2.43-44.13)

0.000

=2500

10 (1.3)

789 (98.7)

799

 
 

Maturity at birth

At term Yes

10 (1.3)

789 (98.7)

799

0.08 (0.02-0.41)

0.000

No

3 (13)

20 (87)

23

 
 

Prematurity Yes

3 (13)

20 (87)

23

11.84 (2.43-44.13)

0.000

No

10 (1.3)

789 (98.7)

799

 
 

Medical past history

Recurrent UTI Yes

2 (10)

18 (90)

20

7.99 (1.12-35)

0.040

No

11 (1.4)

791 (98.6)

802

 
 

Family past history

HTN in family Yes

8 (3.6)

212 (96.4)

220

4.51 (1.44-15.26)

0.010

No

5 (0.8)

597 (99.2)

602

 
 

Diabetes in family Yes

0 (0)

165 (100)

165

0 (0-1.02)

0.050

No

13 (2)

644 (98)

657

 
 

Overweight inYes

10 (4.9)

193 (95.1)

203

10.64 (3.04-48.29)

0.000

family No

3 (0.5)

616 (99.5)

619

 
 

*p-value from Chi-square test

Of all the variables of the pupil's past history analysed, the birth weight <2500(OR=11.84; CI95=2.43-44.13; p=0.000), the preterm delivery (OR=11.84; CI95=2.43-44.13; p=0.000), the recurrent UTI (OR=7.99; CI95=1.12-35; p=0.040), HTN in family (OR=4.51; CI95=1.44-15.26; p=0.010) and overweight in family (OR=10.64; CI95=3.04-48.29; p=0.000)were risk factors of hypertension. Meanwhile, born at term(OR=0.08; CI95=0.02-0.41; p=0.000)was a protecting factor.

VIII.6.6BMI status

Table XXVI: BMI status and HTN

 

Hypertensive

n(%)

Non hypertensive

n(%)

Total

N

OR (CI 95%)

P-value*

Normal weight

7 (0.9)

750 (99.1)

757

 
 

Excess weight**

6 (10)

54 (90)

60

11.98 (3.64-37.96)

0.000

*p-value from Chi-square test

**Overweight and obesity

Excess weight (overweight and obesity) was an associated factor of hypertension (OR=11.98; CI95=3.64-37.96; p=0.000).

VIII.7MULTIVARIATE ANALYSIS OF FACTORS ASSOCIATED OF HYPERTENSION

Table XXVII: Multivariate analysis with logistic regression

Variables

Odds Ratio

C.I 95%

P-Value

Age >10 years

6.4614

1.2581 - 33.1841

0.0254

Birth weight <2500grams

4.1894

0.0575 - 305.4815

0.5127

At term

0.0845

0.0216 - 0.3307

0.0004

Prematurity

1.578

0.0216 - 115.3462

0.835

Recurrent urinary tract infection

3.7988

0.4371 - 33.0119

0.2263

HTN in family

1.1318

0.2845 - 4.5025

0.8605

Overweight in family

7.4624

1.6906 - 32.9401

0.008

Excess weight*

10.1069

2.5094 - 40.7063

0.0011

*Overweight and obesity

Out of the factors that were significant in bivariate analysis, the pupil's age>10 years old(OR=6.4614; CI95=1.2581 - 33.1841; p=0.0254), overweight in family (OR=7.4624; CI95=1.6906 - 32.9401; p=0.008) and excess weight (OR=10.1069; CI95=2.5094 - 40.7063; p=0.0011)persisted as risk factors of hypertension after multivariate analysis with logistic regression; and born at term(OR=0.0845; CI95=0.0216 - 0.3307; p=0.0004) persisted asa protecting factor.

CHAPTER IX: Discussion

The study was a school-based cross-sectional analytic study carried out in 13 primary schools in Mbankomo subdivision found in theMefou and Akono division, Centre Region. A total of 822 children were enrolled using a two stage cluster sampling method. The study was carried out to determine the prevalence hypertension and its associated factors in primary school children in Mbankomo subdivision.

DIFFICULTIES OF THE STUDY

Even though the analysis carried out permitted us to determine the prevalence of hypertension, as well as the associated factors, we were confronted with some difficulties in the field. They include: refusal to participate in the study, poorly filled questionnaires, and absence from school on the days the BP and anthropometric measurements were to be taken.

LIMITS OF THE STUDY

The fact that we did not carry out urine dipstick test on all the pupils limited analysis on renal involvement in HTN.

The majority of legal tutors (88%) refused to give elements of their socioeconomic status, limiting its association with HTN in study.

IX .1CHARACTERISTICS OF THE STUDY POPULATION

There was a female predominance (57.1%) with a sex ratio of 1.3. This female predominance was equally described by Bissohong (54%) in Bertoua'''''''''''''''''''''''''''''''[24], Fotso(52%) in Yaounde '''''''''''''''''''''''`'''''''''''''[25]and Sadoh et al in Nigeria in 2014 (51.1%) -[74]. This predominance reflects that of the general population [75]. On the other hand, Samain in Buea (50.9%)[26], and Maj et al in India (56%) [76] found a male predominance.

The mean age of the pupils was 9 years with extremes of 5 and 17 years, and the most represented age group was 8-10 years. This age group is similar to that found by Samain[26], which corresponds to primary school age.

We found that, 82.8% of the pupils were from public schools, and 17.2% from private schools. This could be attributed to the fact that there are fewer private schools compared to public schools in the study area. This finding was equally noted by Bissohong in Bertoua'''''''''''''''''''''''''''''''[24](61% public vs 39% private), and Sadoh et al 2014 (54.9% public vs 45.1% private) -[74]. This was not the case in the study carried out by Samain in Buea (46.1% public vs 53.9% private) [26].

In this study, the pupils were predominantly from the semi urban setting (56.7%). This could be explained by the high number of parents from the rural setting who refused to participate in the study due to their low level of comprehension on its necessity, and the absence of many pupils from school during data collection. This predominance was likewise in Nihaz et al's study 2016 in India [66].

Considering the socioeconomic status, only 12% of the study populationresponded with 87.5% being from a middle class household. It could be that the few who responded were those who understood the importance of the study.Our findings are in sharp contrast toBadawi et al in 2012 in Egypt-[77] with 48% of pupils from a middle class homeswhile Sadoh et al -[74] in Nigeria, noted more children from lower class homes.

IX .2ANTHROPOMETRIC PARAMETERS

The BMI as recommended by the WHO was used to classify the nutritional status in our study population, with excess weight known to be an associated risk factor to cardiovascular diseases '-[6].Excess weight was noted in 7.3% of the pupils (6.7% overweight and 0.6% obese). This occurred predominantly within the 5- 7 years age group. This figure is lower compared to findings made by other authors in Cameroon: 32.9%, 20.4% and 31% by Mekone, Bissohong and Samain respectively[24, 26, 78]. This figure is still lower compared to findings made by other African and chinese authors -[49,70,79]. The gap of the prevalence of excess weight between this study and other studies could be explained principally by the fact that, our study was carried out mainly in rural and semi urban setting where as the others carried out in urban settings: probably because of reduced physical activity and overconsumption of processed and energy-dense foods.

IX .3PREVALENCE OF HYPERTENSION

The classification of BP levels in this study was done according to the Guidelines of the American Academy of Pediatrics in 2017: Following these guidelines, 90.3% of the pupils had a normal BP level, 8.1% ofpupils had an elevated BP level and 1.6% hypertensive.This prevalence of HTN was lower than the levels reported by Fotso in 2013'''''''''''''''''''''''`'''''''''''''[25], Bissohong in 2015'''''''''''''''''''''''''''''''[24], and Samain in 2016 [26]. Higher prevalences have equally been reported in other African studies ranging from 3.5% to 10.8% (reported byFarah et al in 2014 in Uganda, Frances et al in 2017 in Nigeria andMuhihi et al in 2018 in Tanzania respectively) -[81-83]. Again, higher prevalences have also been described by some authors around the world [8,84,85]. Kishorkumar et al carried out a study aimed at determining the prevalence of HTN among 310 school children in a rural area of Tamil Nadu in India, and showed a prevalence of HTN of 10% and preHTN of 14.2%[86]. The difference between these prevalences and ours, could be attributed to the fact that the sample sizes were lower than ours, the studies were carried out in urban settings and the authors used the United States-based 2004 Task Force Report Update and French Reference Criteria which all tend to overestimate the BP.In the same light, genetic predisposition and sedentarity marked by more obese children in other studies mightequally contribute to this prevalence gap.However, a lower prevalence of 1% and 0.6% was determined by Adrogue et al in 2001 and Goon et al in 2013 respectively -[87,88], which could be due to the use of either an automated BP device which underestimates DBP by about 2.1mmHg or the use of a different reference critera: Second Task Force recommendation which underestimates BP.

In our study, HTN was predominantly systolic in a proportion of 1.6% compared to 0.4% that was diastolic. Similar results were noted in other studies[26,85,89]. This difference could be due to the increase in the activation of the sympathetic nervous system due to stress which elevated SBP of pupils in our study[80].This finding was contrary to that observed by Bissohongwho reported diastolic predominance in a proportion of 2.6% for elevated DBP and 0.9% for elevatedSBP'''''''''''''''''''''''''''''''[24].

In our study population, the prevalence of HTN was higher within the age range 14 - 17 years. Bhuvaneswar et al[90]and many other studies noted high BP levels at preadolescence and adolescence [8,85,89,91].This could be attributed to an increase in body mass and gonadal hormones (testosterone, oestrogene and progesterone) in pubertal period.

The prevalence of hypertension was slightly higher in females 10 (2.1%) than in males 3 (0.8%) in our study. A similar finding was noted by Okoh et al in Nigeria in 2012 [23],Samain in 2016 [26].

The difference prevalences between the male and the female gender could be due to the fact that, there is an increase in large artery stiffness with age, and an onset of body fat mass deposition which starts earlier in girls than in boys during prepuberty and puberty. However, the changes over time in artery stiffness and fat deposition are such that no gender differences are observed in postpuberty [92]. Whereas Goon et al in 2013 [88],and Bissohong in 2015 '''''''''''''''''''''''''''''''[24],noted higher prevalences in males.

The prevalence of HTN was higher among pupils attending public schools with a proportion of 1.7% compared to 0.7% in those attending private schools in our study. Samain in 2016[26]in Buea, equally reported a high prevalence in public schools. This could be explained by public schools authorities who less encouraged physical activities in our study. However, some other studies found a higher prevalence in private schools'''''''''''''''''''''''''''''''[24,84,86]. According to Sarala et al [84], the high prevalence of hypertension in private school children could be attributed to decreased physical activity,change in nutritional habits and life style change.

In our study, HTN was reported to be more present in pupils attending schools in a semi urban setting(1.7%) compared to those attending in a rural setting(1.4%).Nihaz et al in 2016 in a study whose objective wasto determine the prevalence of hypertension and risk factors amongschool children in Kerala, India, demonstrated that the prevalence of combined hypertension and pre-hypertension (BP>90th percentile) was high in the urban areas (16.2%)compared to the rural areas (2.89%) [66]. This was explained by the fact that, a middle to high economic status mostly found in urban homes has got major effect on the nutritional status of pupils. The decreased physical activity in children and adolescents have been related mainly to, computer games, video games, internet gazing, television and movie viewing, overemphasis on academic excellence, and increasing automated transport [66,93].

Out of 13 pupils who were hypertensive, 20% were obese, and 9.0% were overweight. Muhihi et al in Tanzania[83] found that, 52.2% of the children were obese and 27.3% were overweight. It has been shown that excess weight during childhood is a risk factor for systolic hypertension, dyslipidemia, and insulin resistance, suggesting that reduction of the excessive rate of weight gain may exert beneficial effects on blood pressure[66,94,95].

We noted in this study that, SBP and DBP significantly increased with age. Previous reports confirmed this relationship -[26,74]. Age-related increase in blood pressure is partly attributable to increasing weight with age[83]. This positive correlation could also be due to a progressively increased risk of occurring secondary risk factors of elevated BP with age.

The SBP and DBP also,significantly increased with BMI in our study. Other studies observed a similar finding with a significant correlationof BMI with SBP and DBP-'''''''''''''''''''''''`''''''''''''''''''''''''''''''''''''''''''''-[24-26,74,96]. The correlation between BP and BMI in children may highlight the development of metabolic syndrome[83].

IX .4FACTORS ASSOCIATED TO HTN

On bivariate analysis, the characteristics which had a statistically significant influence on HTN were; the age, the birth weight, the term, the past medical history of recurrent UTI, family history of HTN and overweight, and excess weight.

In multivariate analysis, the independent factors associated with HTN were; the pupil's age>10 years old,family history of overweight, andexcess weight. On the other hand,being born at termwas protective.

In our study, pupils older than 10 years were strongly associated to hypertension (p=0.0254). This result is similar to that reported by certain authors notably Bissohong in 2015 in Bertoua'''''''''''''''''''''''''''''''[24]. Juliana et al in 2015 reported that the majority of hypertensive cases were preadolescents and adolescents (p<0.001)           - - [69]. In Muhihi et al's study in 2018 in Tanzania, the prevalence of elevated BP was higher among children aged more than 10 years compared to those aged 10 years or less (p = 0.0029)[83]. This can be explained by the observed trend of increasing blood pressure with increase in body size,probable secondary risk factors, weight and sexual maturity which tends to occur with increasing age'''''''''''''''''''''''''''''''[82].

The family history of overweight was strongly associated to HTN in our study(p=0.008). This was not the case in Bissohong's study, which showed no statistically significant association '''''''''''''''''''''''''''''''[24]. According to Kanciruk et al, family history of obesity can be considered to be both environmental and biological in nature[97]. In terms of environmental risk, parents, in particular mothers, tend to ingrain their personal eating habits as well as their perceptions of weight to their children and, in terms of its biological nature, the genetic influence of overweight/obesity may predispose children to developing this condition. This condition is known to be a precursor of cardiovascular diseases and particularly in HTN.

The present study observed that, the pupils who had excess weight (overweight and obesity) had a higher prevalence of HTN compared to those who didn't have (10% vs 0.9% respectively). We also noted a statistically significant association between excess weight and HTN (p=0.0011). This finding was consistent with that of Samain(p=0.000)[26], Bissohong (p=0.02) '''''''''''''''''''''''''''''''[24], and Arun et al (p=0.001) [91]. This association could be attributable to over activation of the renin-angiotensin and sympathetic nervous systems; insulin resistance; and abnormality in vascular structure and function observed in obese children [94].

Pupils born at term were less likely to be hypertensive. In fact, delivery at term was protective of HTN (p=0.0004). Most studies indicated prematurity as a risk factor of HTN [98,99].The mechanisms by which BP levels appear to be elevated in children and young adults who were preterm are not fully understood. The possible contributing factors include impaired morphological development of glomeruli and fewer nephrons on the basis of interrupted kidney development resulting in small kidneys, microvascular growth arrest and rarefaction building up peripheral vascular resistance [99]. We want to note the subjective nature of reporting of term and preterm delivery because we did not have access to the hospital delivery notes of the pupils from their legal tutors. We could not find any study associating birth at term with HTN.

CHAPTER X: conclusion and recommendations

X.1 CONCLUSION

At the end of our study, we can say that our different objectives have been attained. We can then draw the following conclusions:

· The mean age of the pupils enrolled in the study was 9years (extremes from 5-17years) and the most represented age range was 8-10 years (41.1%). Females were mostly represented in 57.1% giving a sex ratio of 1.3. Pupils mostly attended public schools in 82.8% and were mostly from a semi urban setting in 56.7%. The most represented class was class 6 in 22.6%. Most legal tutors carried out liberal professions (49.8%) and the most represented socio economic status was that of the middle class in 87.5%.

· The prevalence of hypertension was 1.6% (with 1.5% in stage I and 0.1% in stage II) and that of elevated BP was 8.1%. Hypertension was predominantly systolic in 1.6% anddiastolic in 0.4%. There was a positive correlation between age, BMI, and blood pressure.

· After multivariate analysis with logistic regression, only the age> 10years, family history of overweight,excess weight persisted as risk factors of HTN and born at term a protecting factor.

X.2 RECOMMENDATIONS

We will therefore make the following recommendations:

Ø School Authorities

· Reinforce nutrition and physical education in the school curricular.

Ø Medical Staff

· Integrate blood pressure monitoring in children as part of routine examination during routine health/sick medical visits.

Ø Parents

· Encourage healthy eating habits, manual labour and ensure physical activity at home.

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CHAPTER XIi: APPENDIX

APPENDIX I

FICHE D'ENQUETE

TITRE: PREVALENCE ET LES FACTEURS ASSOCIES DE L'HYPERTENSION ARTERIELLE CHEZ LES ELEVES DE L'ECOLE PRIMAIRE DANS L'ARRONDISSEMENT DE MBANKOMO

N° du questionnaire :...........................................

Date de collecte:...........................................

Numéro de Téléphone du tuteur légal:...................................................

Section A

Partie I: Données Socio-Démographiques de votre enfant

1. Nom de l'enfant :............................................

2. Date de naissance:.................................

3. Age:.........................................

4. Sexe: [1] Masculin [2] Féminin

5. Type d'école : [1] Publique [2] Privé

6. Classe : [1] Sil/Class1[2] CP/ Class2[3]CE1/ Class3[4]CE2/ Class 4 [5]CM1/Class 5 [6]CM2/Class 6

7. Quartier : ................................................................

8. Milieu scolaire: [1] Rural [2] Semi-urbain

9. Profession du tuteur légal : [1] Etudiant(e)/ élève [2]Secteur publique[3]Secteur privé [4] Secteur informel [5] Sans emploi [6] Autres...............................

Partie II: Données Socio-Economiques

10. Niveau d'éducation du tuteur légal :..........................................................

11. Profession du tuteur legal :.....................................................

12. PartieV: Antécédents

a. Personnels

1. Quel était son poids de naissance (en grammes) : ....................................

2. Quel était son terme : [1] prématuré(e) [2] A terme

3. A-t-il(elle) déjà été diagnostiqué(e) d'un des problèmes suivant ?

- Problème rénal ou infection urinaire récurrente : [1] Oui [2] Non

- Problème de coeur : [1] Oui [2] Non

- Drépanocytose : [1] Oui [2] Non

4. A-t-il(elle) déjà été diagnostiqué(e) d'une hypertension ? [1] Oui [2] Non

5. Si oui, où est-ce que le diagnostic a été fait? [1] A l'hôpital [2] Hors de l'hôpital.

6. Est-il(elle) sous une médication ? [1] Oui [2] Non

7. Si oui, quel(s) est(sont) le(les) nom(s) de cette(s) médication(s)? [1] Benazepril [2] Fosinopril [3] Enalapril [4]Lisinopril [5] Irbesartan [6]Losartan [7] Propanolol [8] Amlodipine[9] Hydrochlorothiazide [10] Médicament traditionnel [11] Autre(s), précisez........................................

b. Familiaux

8. Y'a-t-il dans la famille l'hypertension artérielle ?[1] Oui [2] Non

9. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

10. Y'a-t-il dans la famille le diabète? [A] Oui [B] Non

11. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

12. Y'a-t-il dans la famille une personne en surpoids ? [1] Oui [2] Non

13. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

PartieV: Antécédents

b. Personnels

14. Quel était son poids de naissance (en grammes) : ....................................

15. Quel était son terme : [1] prématuré(e) [2] A terme

16. A-t-il(elle) déjà été diagnostiqué(e) d'un des problèmes suivant ?

- Problème rénal ou infection urinaire récurrente : [1] Oui [2] Non

- Problème de coeur : [1] Oui [2] Non

- Drépanocytose : [1] Oui [2] Non

17. A-t-il(elle) déjà été diagnostiqué(e) d'une hypertension ? [1] Oui [2] Non

18. Si oui, où est-ce que le diagnostic a été fait? [1] A l'hôpital [2] Hors de l'hôpital.

19. Est-il(elle) sous une médication ? [1] Oui [2] Non

20. Si oui, quel(s) est(sont) le(les) nom(s) de cette(s) médication(s)? [1] Benazepril [2] Fosinopril [3] Enalapril [4]Lisinopril [5] Irbesartan [6]Losartan [7] Propanolol [8] Amlodipine[9] Hydrochlorothiazide [10] Médicament traditionnel [11] Autre(s), précisez........................................

b. Familiaux

21. Y'a-t-il dans la famille l'hypertension artérielle ?[1] Oui [2] Non

22. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

23. Y'a-t-il dans la famille le diabète? [A] Oui [B] Non

24. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

25. Y'a-t-il dans la famille une personne en surpoids ? [1] Oui [2] Non

26. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

PartieV: Antécédents

c. Personnels

27. Quel était son poids de naissance (en grammes) : ....................................

28. Quel était son terme : [1] prématuré(e) [2] A terme

29. A-t-il(elle) déjà été diagnostiqué(e) d'un des problèmes suivant ?

- Problème rénal ou infection urinaire récurrente : [1] Oui [2] Non

- Problème de coeur : [1] Oui [2] Non

- Drépanocytose : [1] Oui [2] Non

30. A-t-il(elle) déjà été diagnostiqué(e) d'une hypertension ? [1] Oui [2] Non

31. Si oui, où est-ce que le diagnostic a été fait? [1] A l'hôpital [2] Hors de l'hôpital.

32. Est-il(elle) sous une médication ? [1] Oui [2] Non

33. Si oui, quel(s) est(sont) le(les) nom(s) de cette(s) médication(s)? [1] Benazepril [2] Fosinopril [3] Enalapril [4]Lisinopril [5] Irbesartan [6]Losartan [7] Propanolol [8] Amlodipine[9] Hydrochlorothiazide [10] Médicament traditionnel [11] Autre(s), précisez........................................

b. Familiaux

34. Y'a-t-il dans la famille l'hypertension artérielle ?[1] Oui [2] Non

35. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

36. Y'a-t-il dans la famille le diabète? [A] Oui [B] Non

37. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

38. Y'a-t-il dans la famille une personne en surpoids ? [1] Oui [2] Non

39. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent[4] Oncle /tante [5] Frère /soeur

Revenue mensuel de la famille par mois (FCFA) : [1] =15.072[2] 15073 -45217 [3] 45.218 - 75.363 [4] 75.364-113.045 [5] 113.046-150.727 [6]150.728-301.454 [7] =301.455

Partie III: Antécédents

a. Personnels

13. Quel était son poids de naissance (en grammes) : ....................................

14. Quel était son terme : [1] Prématuré(e) [2] A terme

15. A-t-il(elle) déjà été diagnostiqué(e) d'un des problèmes suivant ?

- Problème rénal ou infection urinaire récurrente : [1] Oui [2] Non

- Problème de coeur : [1] Oui [2] Non

- Drépanocytose : [1] Oui [2] Non

16. A-t-il(elle) déjà été diagnostiqué(e) d'une hypertension ? [1] Oui [2] Non

17. Si oui, où est-ce que le diagnostic a été fait? [1] A l'hôpital [2] Hors de l'hôpital.

18. Est-il(elle) sous une médication ? [1] Oui [2] Non

19. Si oui, quel(s) est(sont) le(les) nom(s) de cette(s) médication(s)? [1] Benazepril [2] Fosinopril [3] Enalapril [4]Lisinopril [5] Irbesartan [6]Losartan [7] Propanolol [8] Amlodipine [9] Hydrochlorothiazide [10] Médicament traditionnel [11] Autre(s), précisez.....................................

b. Familiaux

20. Y'a-t-il dans la famille l'hypertension artérielle ?[1] Oui [2] Non

21. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent [4] Oncle /tante [5] Frère /soeur

22. Y'a-t-il dans la famille le diabète? [A] Oui [B] Non

23. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent [4] Oncle /tante [5] Frère /soeur

24. Y'a-t-il dans la famille une personne en surpoids ? [1] Oui [2] Non

25. Si oui, chez lequel des membres? [1] Père [2] Mère [3] Grandparent [4] Oncle /tante [5] Frère /soeur

Partie IV: Habitudes alimentaires

26. Nombre de repas par jour: ...........................................

27. Une fois à table, ajoutez-vous?

- Du sel de cuisine : [1] Oui [2] Non - Du cube ou arome : [1] Oui [2] Non

28. Combien de fois consomme t-il/elleen moyenne des fruits par semaine: .....................

29. Combien de fois consomme t-il/elleen moyenne des légumes par semaine: ..................

30. Vous consommez des boissons gazeuses sucrées (jus brassés) ? [1] Occasionnellement [2] Régulièrement

31. Quelle quantité d'eaubuvez-vous en moyenne par jour? [1] Moins d'un demi-litre d'eau[2] Entre 0.5 litre et 1litre d'eau [3] Plus d'un litre d'eau

Partie V: Activité physique et sédentarité

32. Principal moyen de locomotion pour aller à l'école: [1] A pieds [2] En vehicule

33. Si par vehicule, combien de temps de marche tu mets pour le prendre? ...............minutes

34. Si à pieds, combien de temps tu mets pour arriver à l'école? ...........................minutes

35. Pratiquez-vous le sport scolaire? [1] Oui [2] Non

36. Si oui, combien d'heures en moyenne par semaine? ...................................heures.

37. Est-ce que tu fais du sport en dehors de l'école ? [1] Oui [2] Non

38. Si oui, combien de fois par semaine? ..............................................

39. Combien d'heures par jour passes-tu devant la télévision ou les jeux ou l'ordinateur?

[1] Moins d'une heure [2] 1-2 heures [3] Plus de 2 heures

40. Temps de sommeil en heure par jour? [1] moins de 6 heures [2] 6-8 heures [3] Plus de 8 heures

Section B: Paramètres (RESERVE UNIQUEMENT A L'ENQUETEUR)

41. Poids: ......................kg Taille :...................cm

42. Date de mesure : ...................................................

43. Taille percentile ( à partir des courbes de référence)................................

44. IMC(Calculée):.................................................kg/m2

45. IMC Percentile ( à partir des courbes de référence):[1] <5eme[2] entre =5eme et <85eme [3] entre =85eme et <95eme[4] =95eme

Premier passage

46. Pression artérielle: TAS........................ TAD...................

47. TAS percentile pour l'âge, le sexe et la taille : [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

48. TAD percentile: [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

Deuxième passage

49. Pression artérielle: TAS........................ TAD...................

50. TAS percentile pour l'âge, le sexe et la taille : [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

51. TAD percentile: [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

Troisième passage

52. Pression artérielle: TAS........................ TAD...................

53. TAS percentile pour l'âge, le sexe et la taille : [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

54. TAD percentile: [1] < 90eme[2] = 90eme- <95eme[3] = 95eme - <99eme[4] =99eme +5mmHg

55. Bandelette urinaire-Proteinurie :[1] Trace(<30mg/dl) [2] +1(=30-<100mg/dl) [3] +2(=100-<300mg/dl) [4] +3(=300 - <1000mg/dl) [5]+4(=1000mg/dl)

56. Bandelette urinaire-Sang : [1] Oui [2] Non

WORK SHEET

TITLE: PREVALENCE AND ASSOCIATED FACTORS OF HYPERTENSION IN PRIMARY SCHOOL CHILDREN IN THE MBANKOMO SUBDIVISION

Code of the questionnaire: ...........................................

Date of recruitment: ...........................................

Telephone number of legal tutor: ...................................................

 

Section A

Part I: Socio-demographic data of your child

1. Name of the child: ............................................

2. Date of birth: .......................................

3. Age: .....................................................

4. Gender: [1] Male [2] Female

5. School type: [1] Public [2] Private

6. Class: [1] Sil/Class1[2] CP/ Class2[3]CE1/ Class3[4]CE2/ Class 4 [5]CM1/Class 5 [6]CM2/Class 6

7. Quarter: ................................................................

8. School setting: [1] Rural [2] Semi-urban

9. Legal tutor's Occupation: [1] Student [2] Public Sector [3] Private Sector [4] Informal sector [5] Unemployed [6] Other,precise........................................

Part II: Socio-Economic Characteristics

10. Level of education of the legal tutor :....................................................

11. Profession of legal tutor :.............................................................

12. Monthly family income (FCFA) : [1] =15,072 [2] 15,073 - 45,217 [3] 45,218 - 75,363 [4] 75,364-113,045 [5] 113,046 - 150,727 [6]150,728 - 301,454 [7] =301,455

Part III: Past History

a. Personal

13. What was his birth weight (in grams): ....................................

14. What was his/her term ? [1] Premature [2] At term

15. Has he (she) ever been diagnosed with any of the following problems?

- Renal problem or recurrent urinary tract infection: [1] Yes [2] No

- Heart problem: [1] Yes [2] No

- Sickle cell disease: [1] Yes [2] No

16. Has he / she ever been diagnosed with hypertension? [1] Yes [2] No

17. If yes, where was the diagnosis made? [1] In the hospital [2] Out of the hospital.

18. Is he (she) under a medication? [1] Yes [2] No

19. If yes, which one (s) is (are) the name (s) of this medication (s)? [1] Benazepril [2] Fosinopril [3] Enalapril [4] Lisinopril [5] Irbesartan [6] Losartan [7] Propanolol [8] Amlodipine [9] Hydrochlorothiazide [10] Traditional medicine [11] Other (s), please specify ........................................

b. Family

20. Is there any one with hypertension in the family? [1] Yes [2] No

21. If yes, which members? [1] Father [2] Mother [3] Grandparent [4] Uncle / aunt [5] Brother / sister

22. Is there diabetes in the family? [1] Yes [2] No

23. If yes, which members? [1] Father [2] Mother [3] Grandparent [4] Uncle / aunt [5] Brother / sister

24. Is there in the family any fat person? [1] Yes [2] No

25. ??If yes, which members? [1] Father [2] Mother [3] Grandparent [4] Uncle / aunt [5] Brother / sister

Part IV: Feeding habits

26. Number of meals per day: ...........................................

27. Once at the table, do you add?

           - Tablesalt :[1] Yes [2] No   - Cube or aroma: [1] Yes [2] No 

28. How many times does he / she eat fruit on average per week: ..............................................

29. How many times does he / she consume vegetables on average per week: ............................

30. Do you eat sweetened soft drinks (brewed juice)? [1] Occasionally [2] Regularly

31. What quantity of water do you drink on average per day? [1] Less than half a liter of water [2] Between 0.5 liter and 1 liter of water [3] More than one liter of water.

Part V: Physical activity and lifestyle

32. Primary means of transportation to school: [1] On foot [2] By vehicle

33. If by vehicle, how long do you take to take it? .....................minutes

34. If on foot, how long do you take to get to school? ..............................minutes

35. Do you practice school sport? [1] Yes [2] No

36. If yes, how many hours on average per week? ................................... hours.

37. Do you practise sports outside of school? [1] Yes [2] No

38. If yes, how many times a week? ..............................................

39. How many hours a day do you spend watching television and/or games and/or computer?[1] Less than an hour [2] 1-2 hours [3] More than 2 hours

40. Sleep time in hours per day? [1] less than 6 hours [2] 6-8 hours [3] More than 8 hours

Section B: Parameters (ONLY FOR THE INVESTIGATOR)

41. Weight: ..................... .kgHeight: .................. .cm

42. Date of measurement: ...................................................

43. Height Percentile (from the reference curves) ................................

44. BMI (Calculated): ................................................ .kg / m2

45. BMI Percentile (from the reference curves): [1] <5th [2] between =5th and <85th[3] between =85thand <95th[4] =95th

First passage

46. Blood pressure: SBP ............................... DBP................................... ....

47. SBP percentile for age, sex and height: [1] <90th [2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

48. DBP Percentile : [1] <90th[2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

 

Second passage

49. Blood pressure: SBP ............................... DBP................................... ....

50. SBP percentile for age, sex and height: [1] <90th [2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

51. DBP Percentile : [1] <90th[2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

Third passage

52. Blood pressure: SBP ............................... DBP................................... ....

53. SBP percentile for age, sex and height: [1] <90th [2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

54. DBP Percentile : [1] <90th[2] = 90th - <95th[3] = 95th - <99th[4] =99th + 5mmHg

55. Urine dipstick-Proteinuria: [1] Trace (<30mg / dl) [2] +1 (=30 - <100mg / dl) [3] +2 (=100- <300mg / dl) [4] +3 (=300 - <1000mg / dl) [5] +4 (=1000mg / dl)

56. Urine dipstick-Blood : [1] Yes [2] No

APPENDIX II

INFORMED CONSENT FORM

Section I: Information Section

Dear Sir / Madame,

1. Introduction

I am CHIABI EDMOND NGONG,a 7th year medical student of the Faculty of Medicine and Biomedical Sciences of the University of Yaounde I. I am carrying out a study titled «Prevalence and associated Factorsof Hypertension in Primary School Children in theMbankomo subdivision, Centre Region of Cameroon.»

2. Aim of the study

The main aim of this study is to generate data and increase awareness on High blood pressure in children in the rural environment.

3. Invitation & Voluntary Participation

You are kindly invited to enroll your child in this study. We would like you to know that the participation of your child in this study is strictly voluntary. If you decide not enroll your child in this study, your decision will be respected without further questioning. If along the course of the study you decide not to participate any further, you are free to withdraw your child from the studywithout pre- notification, such a decision will be respected without any further questioning.

4. Procedure

During the process, you will be sent a questionnaire to be filled. The investigator will also examine your child by taking his/her blood pressure, the weight,the height and the collected urine. NO BLOOD will be collected throughout the study and NO INVASIVE TESTwill be done.

5. Risks

The study is almost free from risk apart from the fact that a few minutes will be taken off your child's study period to conduct the study.

6. Reimbursements and Benefits

Your child will NOT BE PAID for participating in this study. However he / she might benefit from early diagnosis of childhood and adolescent hypertension and referral to the doctor for follow up.

7. Confidentiality

This will be ensured by not collecting your child's name and other sensitive information. By keeping filled questionnaires in a save where only the investigators have access. The information will be entered into a computer software using codes.

8. Contact in case of Questions

Please if you have any doubts concerning this study; feel free to ask the investigator. Questions can also be directed to the supervisors using the addresses below:

Tel: 693089876

Email: edmondchiabi@gmail.com

Section II: Consent

I.................................................................................... having understood the study, after having the study/consent form thoroughly explained to me, having been given the opportunity to ask questions and time to consider my participation in the study, I do hereby agree to enroll my child to participate in this study.

Yaounde, ............................................

Signature of the participant

NOTICE D'INFORMATION ET DE CONSENTEMENT ÉCLAIRÉ

Cher parents,

Je me nomme CHIABI Edmond NGONG, étudiant en 7e année de Médecine Générale à la Faculté de Médecine et des Sciences Biomédicales de l'Université de Yaoundé I (ex CUSS). Je sollicite votre participation ainsi que celle de votre enfant à l'étude intitulée : ·Prévalence et les facteurs associés de l'hypertension artérielle chez les enfants de l'école primaire dans l'arrondissement de Mbankomo·. 

But

Le but de cette étude est de connaître le niveau de tension artérielle de base de l'enfant « sain » afin de déterminer la prévalence et les facteurs de risque de l'hypertension artérielle en milieu scolaire dans un milieu rural.

Méthodes et procédures

Si vous acceptez de participer à cette étude (vous et votre enfant), vous répondrez au questionnaire qui vous est adressé ; et l'investigateuràl'école, examinera l'enfant par la prise de sa tension artérielle, son poids, sa taille et l'urine collectée. Aucune prise de sang sera faite ni autre examen invasif.

Les risques, effets secondaires ou inconvénients

Nous ne prévoyons pas de risques, des effets secondaires ou inconvénients quant à la participation à cette étude. Aucun revenu financier n'est engagé en participant à l'étude.

La confidentialité et l'Éthique
Toutes les informations recueillies dans le cadre de cette étude seront anonymes et confidentielles. L'étude sera effectuée selon les principes et directives nationales et internationales applicables en matière d'Éthique.

Communication des résultats

Pour plus ample information vous pourrez directement nous contacter personnellement au :

Tel: 693089876

Email: edmondchiabi@gmail.com

FORMULAIRE DE CONSENTEMENT DES PARENTS

(Renvoyez nous ce consentement après signature et le questionnaire dûment remplis)

Je soussigné Mme /Mr ................................................................. ..................................................................................................

Parent de l'enfant ....................................................... Atteste avoir reçu toutes les informations relatives à l'étude : « Prévalence et les facteurs associés de l'hypertension artérielle chez les enfants de l'école primaire dans l'arrondissement de Mbankomo »

J'accepte librement de participer à l'étude ainsi que mon enfant, en répondant à toutes les questions qui me seront posées et en soumettant mon enfant à la réalisation de la procédure de l'étude qui m'a été clairement expliquée.

J'ai lu cette fiche de consentement éclairée et en ai reçu une copie ; je ne demande aucune rémunération aux investigateurs de ce travail.

J'ai compris le but de l'étude, ses avantages sur la prise en charge et la prévention de l'hypertension artérielle en milieu scolaire ; j'accepte que les données recueillies puissent être exploitées pour la recherche scientifique.

Lu et approuvé.

Date:...................................

Signature du participant

APPENDIX III

SECTION 1: BLOOD PRESSURE TABLES

BP Levels for Boys by Age and Height Percentile

Age (y)

BP Percentile

SBP (mm?Hg)

DBP (mm?Hg)

Height Percentile or Measured Height

Height Percentile or Measured Height

5%

10%

25%

50%

75%

90%

95%

5%

10%

25%

50%

75%

90%

95%

1

Height (in)

30.4

30.8

31.6

32.4

33.3

34.1

34.6

30.4

30.8

31.6

32.4

33.3

34.1

34.6

Height (cm)

77.2

78.3

80.2

82.4

84.6

86.7

87.9

77.2

78.3

80.2

82.4

84.6

86.7

87.9

50th

85

85

86

86

87

88

88

40

40

40

41

41

42

42

90th

98

99

99

100

100

101

101

52

52

53

53

54

54

54

95th

102

102

103

103

104

105

105

54

54

55

55

56

57

57

95th + 12 mm?Hg

114

114

115

115

116

117

117

66

66

67

67

68

69

69

2

Height (in)

33.9

34.4

35.3

36.3

37.3

38.2

38.8

33.9

34.4

35.3

36.3

37.3

38.2

38.8

Height (cm)

86.1

87.4

89.6

92.1

94.7

97.1

98.5

86.1

87.4

89.6

92.1

94.7

97.1

98.5

50th

87

87

88

89

89

90

91

43

43

44

44

45

46

46

90th

100

100

101

102

103

103

104

55

55

56

56

57

58

58

95th

104

105

105

106

107

107

108

57

58

58

59

60

61

61

95th + 12 mm?Hg

116

117

117

118

119

119

120

69

70

70

71

72

73

73

3

Height (in)

36.4

37

37.9

39

40.1

41.1

41.7

36.4

37

37.9

39

40.1

41.1

41.7

Height (cm)

92.5

93.9

96.3

99

101.8

104.3

105.8

92.5

93.9

96.3

99

101.8

104.3

105.8

50th

88

89

89

90

91

92

92

45

46

46

47

48

49

49

90th

101

102

102

103

104

105

105

58

58

59

59

60

61

61

95th

106

106

107

107

108

109

109

60

61

61

62

63

64

64

95th + 12 mm?Hg

118

118

119

119

120

121

121

72

73

73

74

75

76

76

4

Height (in)

38.8

39.4

40.5

41.7

42.9

43.9

44.5

38.8

39.4

40.5

41.7

42.9

43.9

44.5

Height (cm)

98.5

100.2

102.9

105.9

108.9

111.5

113.2

98.5

100.2

102.9

105.9

108.9

111.5

113.2

50th

90

90

91

92

93

94

94

48

49

49

50

51

52

52

90th

102

103

104

105

105

106

107

60

61

62

62

63

64

64

95th

107

107

108

108

109

110

110

63

64

65

66

67

67

68

95th + 12 mm?Hg

119

119

120

120

121

122

122

75

76

77

78

79

79

80

5

Height (in)

41.1

41.8

43.0

44.3

45.5

46.7

47.4

41.1

41.8

43.0

44.3

45.5

46.7

47.4

Height (cm)

104.4

106.2

109.1

112.4

115.7

118.6

120.3

104.4

106.2

109.1

112.4

115.7

118.6

120.3

50th

91

92

93

94

95

96

96

51

51

52

53

54

55

55

90th

103

104

105

106

107

108

108

63

64

65

65

66

67

67

95th

107

108

109

109

110

111

112

66

67

68

69

70

70

71

95th + 12 mm?Hg

119

120

121

121

122

123

124

78

79

80

81

82

82

83

6

Height (in)

43.4

44.2

45.4

46.8

48.2

49.4

50.2

43.4

44.2

45.4

46.8

48.2

49.4

50.2

Height (cm)

110.3

112.2

115.3

118.9

122.4

125.6

127.5

110.3

112.2

115.3

118.9

122.4

125.6

127.5

50th

93

93

94

95

96

97

98

54

54

55

56

57

57

58

90th

105

105

106

107

109

110

110

66

66

67

68

68

69

69

95th

108

109

110

111

112

113

114

69

70

70

71

72

72

73

95th + 12 mm?Hg

120

121

122

123

124

125

126

81

82

82

83

84

84

85

7

Height (in)

45.7

46.5

47.8

49.3

50.8

52.1

52.9

45.7

46.5

47.8

49.3

50.8

52.1

52.9

Height (cm)

116.1

118

121.4

125.1

128.9

132.4

134.5

116.1

118

121.4

125.1

128.9

132.4

134.5

50th

94

94

95

97

98

98

99

56

56

57

58

58

59

59

90th

106

107

108

109

110

111

111

68

68

69

70

70

71

71

95th

110

110

111

112

114

115

116

71

71

72

73

73

74

74

95th + 12 mm?Hg

122

122

123

124

126

127

128

83

83

84

85

85

86

86

8

Height (in)

47.8

48.6

50

51.6

53.2

54.6

55.5

47.8

48.6

50

51.6

53.2

54.6

55.5

Height (cm)

121.4

123.5

127

131

135.1

138.8

141

121.4

123.5

127

131

135.1

138.8

141

50th

95

96

97

98

99

99

100

57

57

58

59

59

60

60

90th

107

108

109

110

111

112

112

69

70

70

71

72

72

73

95th

111

112

112

114

115

116

117

72

73

73

74

75

75

75

95th + 12 mm?Hg

123

124

124

126

127

128

129

84

85

85

86

87

87

87

9

Height (in)

49.6

50.5

52

53.7

55.4

56.9

57.9

49.6

50.5

52

53.7

55.4

56.9

57.9

Height (cm)

126

128.3

132.1

136.3

140.7

144.7

147.1

126

128.3

132.1

136.3

140.7

144.7

147.1

50th

96

97

98

99

100

101

101

57

58

59

60

61

62

62

90th

107

108

109

110

112

113

114

70

71

72

73

74

74

74

95th

112

112

113

115

116

118

119

74

74

75

76

76

77

77

95th + 12 mm?Hg

124

124

125

127

128

130

131

86

86

87

88

88

89

89

10

Height (in)

51.3

52.2

53.8

55.6

57.4

59.1

60.1

51.3

52.2

53.8

55.6

57.4

59.1

60.1

Height (cm)

130.2

132.7

136.7

141.3

145.9

150.1

152.7

130.2

132.7

136.7

141.3

145.9

150.1

152.7

50th

97

98

99

100

101

102

103

59

60

61

62

63

63

64

90th

108

109

111

112

113

115

116

72

73

74

74

75

75

76

95th

112

113

114

116

118

120

121

76

76

77

77

78

78

78

95th + 12 mm?Hg

124

125

126

128

130

132

133

88

88

89

89

90

90

90

11

Height (in)

53

54

55.7

57.6

59.6

61.3

62.4

53

54

55.7

57.6

59.6

61.3

62.4

Height (cm)

134.7

137.3

141.5

146.4

151.3

155.8

158.6

134.7

137.3

141.5

146.4

151.3

155.8

158.6

50th

99

99

101

102

103

104

106

61

61

62

63

63

63

63

90th

110

111

112

114

116

117

118

74

74

75

75

75

76

76

95th

114

114

116

118

120

123

124

77

78

78

78

78

78

78

95th + 12 mm?Hg

126

126

128

130

132

135

136

89

90

90

90

90

90

90

12

Height (in)

55.2

56.3

58.1

60.1

62.2

64

65.2

55.2

56.3

58.1

60.1

62.2

64

65.2

Height (cm)

140.3

143

147.5

152.7

157.9

162.6

165.5

140.3

143

147.5

152.7

157.9

162.6

165.5

50th

101

101

102

104

106

108

109

61

62

62

62

62

63

63

90th

113

114

115

117

119

121

122

75

75

75

75

75

76

76

95th

116

117

118

121

124

126

128

78

78

78

78

78

79

79

95th + 12 mm?Hg

128

129

130

133

136

138

140

90

90

90

90

90

91

91

13

Height (in)

57.9

59.1

61

63.1

65.2

67.1

68.3

57.9

59.1

61

63.1

65.2

67.1

68.3

Height (cm)

147

150

154.9

160.3

165.7

170.5

173.4

147

150

154.9

160.3

165.7

170.5

173.4

50th

103

104

105

108

110

111

112

61

60

61

62

63

64

65

90th

115

116

118

121

124

126

126

74

74

74

75

76

77

77

95th

119

120

122

125

128

130

131

78

78

78

78

80

81

81

95th and 12 mm?Hg

131

132

134

137

140

142

143

90

90

90

90

92

93

93

14

Height (in)

60.6

61.8

63.8

65.9

68.0

69.8

70.9

60.6

61.8

63.8

65.9

68.0

69.8

70.9

Height (cm)

153.8

156.9

162

167.5

172.7

177.4

180.1

153.8

156.9

162

167.5

172.7

177.4

180.1

50th

105

106

109

111

112

113

113

60

60

62

64

65

66

67

90th

119

120

123

126

127

128

129

74

74

75

77

78

79

80

95th

123

125

127

130

132

133

134

77

78

79

81

82

83

84

95th and 12 mm?Hg

135

137

139

142

144

145

146

89

90

91

93

94

95

96

15

Height (in)

62.6

63.8

65.7

67.8

69.8

71.5

72.5

62.6

63.8

65.7

67.8

69.8

71.5

72.5

Height (cm)

159

162

166.9

172.2

177.2

181.6

184.2

159

162

166.9

172.2

177.2

181.6

184.2

50th

108

110

112

113

114

114

114

61

62

64

65

66

67

68

90th

123

124

126

128

129

130

130

75

76

78

79

80

81

81

95th

127

129

131

132

134

135

135

78

79

81

83

84

85

85

95th and 12 mm?Hg

139

141

143

144

146

147

147

90

91

93

95

96

97

97

16

Height (in)

63.8

64.9

66.8

68.8

70.7

72.4

73.4

63.8

64.9

66.8

68.8

70.7

72.4

73.4

Height (cm)

162.1

165

169.6

174.6

179.5

183.8

186.4

162.1

165

169.6

174.6

179.5

183.8

186.4

50th

111

112

114

115

115

116

116

63

64

66

67

68

69

69

90th

126

127

128

129

131

131

132

77

78

79

80

81

82

82

95th

130

131

133

134

135

136

137

80

81

83

84

85

86

86

95th and 12 mm?Hg

142

143

145

146

147

148

149

92

93

95

96

97

98

98

17

Height (in)

64.5

65.5

67.3

69.2

71.1

72.8

73.8

64.5

65.5

67.3

69.2

71.1

72.8

73.8

Height (cm)

163.8

166.5

170.9

175.8

180.7

184.9

187.5

163.8

166.5

170.9

175.8

180.7

184.9

187.5

50th

114

115

116

117

117

118

118

65

66

67

68

69

70

70

90th

128

129

130

131

132

133

134

78

79

80

81

82

82

83

95th

132

133

134

135

137

138

138

81

82

84

85

86

86

87

95th and 12 mm?Hg

144

145

146

147

149

150

150

93

94

96

97

98

98

99

BP Levels for Girls by Age and Height Percentile

Age (y)

BP Percentile

SBP (mm?Hg)

DBP (mm?Hg)

Height Percentile or Measured Height

Height Percentile or Measured Height

5%

10%

25%

50%

75%

90%

95%

5%

10%

25%

50%

75%

90%

95%

1

Height (in)

29.7

30.2

30.9

31.8

32.7

33.4

33.9

29.7

30.2

30.9

31.8

32.7

33.4

33.9

Height (cm)

75.4

76.6

78.6

80.8

83

84.9

86.1

75.4

76.6

78.6

80.8

83

84.9

86.1

50th

84

85

86

86

87

88

88

41

42

42

43

44

45

46

90th

98

99

99

100

101

102

102

54

55

56

56

57

58

58

95th

101

102

102

103

104

105

105

59

59

60

60

61

62

62

95th + 12 mm?Hg

113

114

114

115

116

117

117

71

71

72

72

73

74

74

2

Height (in)

33.4

34

34.9

35.9

36.9

37.8

38.4

33.4

34

34.9

35.9

36.9

37.8

38.4

Height (cm)

84.9

86.3

88.6

91.1

93.7

96

97.4

84.9

86.3

88.6

91.1

93.7

96

97.4

50th

87

87

88

89

90

91

91

45

46

47

48

49

50

51

90th

101

101

102

103

104

105

106

58

58

59

60

61

62

62

95th

104

105

106

106

107

108

109

62

63

63

64

65

66

66

95th + 12 mm?Hg

116

117

118

118

119

120

121

74

75

75

76

77

78

78

3

Height (in)

35.8

36.4

37.3

38.4

39.6

40.6

41.2

35.8

36.4

37.3

38.4

39.6

40.6

41.2

Height (cm)

91

92.4

94.9

97.6

100.5

103.1

104.6

91

92.4

94.9

97.6

100.5

103.1

104.6

50th

88

89

89

90

91

92

93

48

48

49

50

51

53

53

90th

102

103

104

104

105

106

107

60

61

61

62

63

64

65

95th

106

106

107

108

109

110

110

64

65

65

66

67

68

69

95th + 12 mm?Hg

118

118

119

120

121

122

122

76

77

77

78

79

80

81

4

Height (in)

38.3

38.9

39.9

41.1

42.4

43.5

44.2

38.3

38.9

39.9

41.1

42.4

43.5

44.2

Height (cm)

97.2

98.8

101.4

104.5

107.6

110.5

112.2

97.2

98.8

101.4

104.5

107.6

110.5

112.2

50th

89

90

91

92

93

94

94

50

51

51

53

54

55

55

90th

103

104

105

106

107

108

108

62

63

64

65

66

67

67

95th

107

108

109

109

110

111

112

66

67

68

69

70

70

71

95th + 12 mm?Hg

119

120

121

121

122

123

124

78

79

80

81

82

82

83

5

Height (in)

40.8

41.5

42.6

43.9

45.2

46.5

47.3

40.8

41.5

42.6

43.9

45.2

46.5

47.3

Height (cm)

103.6

105.3

108.2

111.5

114.9

118.1

120

103.6

105.3

108.2

111.5

114.9

118.1

120

50th

90

91

92

93

94

95

96

52

52

53

55

56

57

57

90th

104

105

106

107

108

109

110

64

65

66

67

68

69

70

95th

108

109

109

110

111

112

113

68

69

70

71

72

73

73

95th + 12 mm?Hg

120

121

121

122

123

124

125

80

81

82

83

84

85

85

6

Height (in)

43.3

44

45.2

46.6

48.1

49.4

50.3

43.3

44

45.2

46.6

48.1

49.4

50.3

Height (cm)

110

111.8

114.9

118.4

122.1

125.6

127.7

110

111.8

114.9

118.4

122.1

125.6

127.7

50th

92

92

93

94

96

97

97

54

54

55

56

57

58

59

90th

105

106

107

108

109

110

111

67

67

68

69

70

71

71

95th

109

109

110

111

112

113

114

70

71

72

72

73

74

74

95th + 12 mm?Hg

121

121

122

123

124

125

126

82

83

84

84

85

86

86

7

Height (in)

45.6

46.4

47.7

49.2

50.7

52.1

53

45.6

46.4

47.7

49.2

50.7

52.1

53

Height (cm)

115.9

117.8

121.1

124.9

128.8

132.5

134.7

115.9

117.8

121.1

124.9

128.8

132.5

134.7

50th

92

93

94

95

97

98

99

55

55

56

57

58

59

60

90th

106

106

107

109

110

111

112

68

68

69

70

71

72

72

95th

109

110

111

112

113

114

115

72

72

73

73

74

74

75

95th + 12 mm?Hg

121

122

123

124

125

126

127

84

84

85

85

86

86

87

8

Height (in)

47.6

48.4

49.8

51.4

53

54.5

55.5

47.6

48.4

49.8

51.4

53

54.5

55.5

Height (cm)

121

123

126.5

130.6

134.7

138.5

140.9

121

123

126.5

130.6

134.7

138.5

140.9

50th

93

94

95

97

98

99

100

56

56

57

59

60

61

61

90th

107

107

108

110

111

112

113

69

70

71

72

72

73

73

95th

110

111

112

113

115

116

117

72

73

74

74

75

75

75

95th + 12 mm?Hg

122

123

124

125

127

128

129

84

85

86

86

87

87

87

9

Height (in)

49.3

50.2

51.7

53.4

55.1

56.7

57.7

49.3

50.2

51.7

53.4

55.1

56.7

57.7

Height (cm)

125.3

127.6

131.3

135.6

140.1

144.1

146.6

125.3

127.6

131.3

135.6

140.1

144.1

146.6

50th

95

95

97

98

99

100

101

57

58

59

60

60

61

61

90th

108

108

109

111

112

113

114

71

71

72

73

73

73

73

95th

112

112

113

114

116

117

118

74

74

75

75

75

75

75

95th + 12 mm?Hg

124

124

125

126

128

129

130

86

86

87

87

87

87

87

10

Height (in)

51.1

52

53.7

55.5

57.4

59.1

60.2

51.1

52

53.7

55.5

57.4

59.1

60.2

Height (cm)

129.7

132.2

136.3

141

145.8

150.2

152.8

129.7

132.2

136.3

141

145.8

150.2

152.8

50th

96

97

98

99

101

102

103

58

59

59

60

61

61

62

90th

109

110

111

112

113

115

116

72

73

73

73

73

73

73

95th

113

114

114

116

117

119

120

75

75

76

76

76

76

76

95th + 12 mm?Hg

125

126

126

128

129

131

132

87

87

88

88

88

88

88

11

Height (in)

53.4

54.5

56.2

58.2

60.2

61.9

63

53.4

54.5

56.2

58.2

60.2

61.9

63

Height (cm)

135.6

138.3

142.8

147.8

152.8

157.3

160

135.6

138.3

142.8

147.8

152.8

157.3

160

50th

98

99

101

102

104

105

106

60

60

60

61

62

63

64

90th

111

112

113

114

116

118

120

74

74

74

74

74

75

75

95th

115

116

117

118

120

123

124

76

77

77

77

77

77

77

95th + 12 mm?Hg

127

128

129

130

132

135

136

88

89

89

89

89

89

89

12

Height (in)

56.2

57.3

59

60.9

62.8

64.5

65.5

56.2

57.3

59

60.9

62.8

64.5

65.5

Height (cm)

142.8

145.5

149.9

154.8

159.6

163.8

166.4

142.8

145.5

149.9

154.8

159.6

163.8

166.4

50th

102

102

104

105

107

108

108

61

61

61

62

64

65

65

90th

114

115

116

118

120

122

122

75

75

75

75

76

76

76

95th

118

119

120

122

124

125

126

78

78

78

78

79

79

79

95th and 12 mm?Hg

130

131

132

134

136

137

138

90

90

90

90

91

91

91

13

Height (in)

58.3

59.3

60.9

62.7

64.5

66.1

67

58.3

59.3

60.9

62.7

64.5

66.1

67

Height (cm)

148.1

150.6

154.7

159.2

163.7

167.8

170.2

148.1

150.6

154.7

159.2

163.7

167.8

170.2

50th

104

105

106

107

108

108

109

62

62

63

64

65

65

66

90th

116

117

119

121

122

123

123

75

75

75

76

76

76

76

95th

121

122

123

124

126

126

127

79

79

79

79

80

80

81

95th + 12 mm?Hg

133

134

135

136

138

138

139

91

91

91

91

92

92

93

14

Height (in)

59.3

60.2

61.8

63.5

65.2

66.8

67.7

59.3

60.2

61.8

63.5

65.2

66.8

67.7

Height (cm)

150.6

153

156.9

161.3

165.7

169.7

172.1

150.6

153

156.9

161.3

165.7

169.7

172.1

50th

105

106

107

108

109

109

109

63

63

64

65

66

66

66

90th

118

118

120

122

123

123

123

76

76

76

76

77

77

77

95th

123

123

124

125

126

127

127

80

80

80

80

81

81

82

95th + 12 mm?Hg

135

135

136

137

138

139

139

92

92

92

92

93

93

94

15

Height (in)

59.7

60.6

62.2

63.9

65.6

67.2

68.1

59.7

60.6

62.2

63.9

65.6

67.2

68.1

Height (cm)

151.7

154

157.9

162.3

166.7

170.6

173

151.7

154

157.9

162.3

166.7

170.6

173

50th

105

106

107

108

109

109

109

64

64

64

65

66

67

67

90th

118

119

121

122

123

123

124

76

76

76

77

77

78

78

95th

124

124

125

126

127

127

128

80

80

80

81

82

82

82

95th + 12 mm?Hg

136

136

137

138

139

139

140

92

92

92

93

94

94

94

16

Height (in)

59.9

60.8

62.4

64.1

65.8

67.3

68.3

59.9

60.8

62.4

64.1

65.8

67.3

68.3

Height (cm)

152.1

154.5

158.4

162.8

167.1

171.1

173.4

152.1

154.5

158.4

162.8

167.1

171.1

173.4

50th

106

107

108

109

109

110

110

64

64

65

66

66

67

67

90th

119

120

122

123

124

124

124

76

76

76

77

78

78

78

95th

124

125

125

127

127

128

128

80

80

80

81

82

82

82

95th + 12 mm?Hg

136

137

137

139

139

140

140

92

92

92

93

94

94

94

17

Height (in)

60.0

60.9

62.5

64.2

65.9

67.4

68.4

60.0

60.9

62.5

64.2

65.9

67.4

68.4

Height (cm)

152.4

154.7

158.7

163.0

167.4

171.3

173.7

152.4

154.7

158.7

163.0

167.4

171.3

173.7

50th

107

108

109

110

110

110

111

64

64

65

66

66

66

67

90th

120

121

123

124

124

125

125

76

76

77

77

78

78

78

95th

125

125

126

127

128

128

128

80

80

80

81

82

82

82

95th + 12 mm?Hg

137

137

138

139

140

140

140

92

92

92

93

94

94

94

SECTION 2: WHO GROWTH CHARTS FOR CHILDREN

APPENDIX IV

MISCELLANEOUS

Indications for Blood Pressure Monitoring in Children < 3years

· History of prematurity, very low birth weight, or other neonatal complication requiring intensive care

· Congenital heart disease (repaired or not)

· Recurrent urinary tract infections, hematuria, or proteinuria

· Known renal disease or urologic malformations

· Family history of congenital renal disease

· Solid organ transplant

· Malignancy or bone marrow transplant

· Treatment with drugs known to raise BP

· Other systemic illnesses associated with hypertension (neurofibromatosis, tuberous sclerosis, etc.)

· Evidence of elevated intracranial pressure

Table I: Laboratory Tests for the Child with Hypertension

Table II: Antihypertensive medications with FDA approval for use in children

Table III: Oral and Intravenous Antihypertensive Medications for Acute Severe HTN

Table IV: Kuppuswamy's socio-economic status scale -revision for 2015

APPENDIX V

AUTHORIZATIONS






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