Prevalence of hypertension in primary school-children in Port Harcourt, Nigeria

Hypertension among adolescents in sub-Saharan Africa: a systematic review

Introduction

Hypertension (HTN) among adolescents is common in high-income countries, and leads to increased premature cardiovascular diseases (CVD). In sub-Saharan Africa (SSA), the prevalence of HTN among adolescents, associated risk factors and CVD complications are not well-described. Such data is needed for planning public health programs to prevent premature CVD in SSA.

Methods

We systematically searched 5 databases (MEDLINE, Embase, Google Scholar, Web of Science, and African Index Medicus) from their establishment to December 2021. Key search terms were: adolescent, arterial hypertension, and names of the 48 countries in SSA. We used Covidence® to manage the search results. The review was registered in the Open Science Framework (OSF) https://osf.io/p5sbt/.

Results

We identified 4,008 articles out of which we screened 3,088 abstracts, and reviewed 583 full-text articles. We finally included 92 articles that were published between 1968 to December 2021. The majority were cross-sectional studies (80%) and conducted in school settings (78%). The risk of bias was low for 59 studies (64.1%), moderate for 29 studies (31.5%), and high for 4 studies (4.3%). Overall, the prevalence of HTN varied widely from 0.18% to 34.0% with a median (IQR) of 5.5% (3.1%, 11.1%). It was relatively higher in studies using automated blood pressure (BP) devices, and in studies defining HTN using thresholds based on percentile BP distribution for one's height, age, and sex. In addition, the prevalence of HTN was significantly higher in studies from Southern Africa region of SSA and positively correlated with the year of publication. Across studies, traditional risk factors such as age, sex, body mass index, and physical inactivity, were commonly found to be associated with HTN. In contrast, non-traditional risk factors related to poverty and tropical diseases were rarely assessed. Only three studies investigated the CVD complications related to HTN in the study population.

Conclusion

The prevalence of HTN among adolescents in SSA is high indicating that this is a major health problem. Data on non-traditional risk factors and complications are scarce. Longitudinal studies are needed to clearly define the rates, causes, and complications of HTN.

Systematic Review Registration

https://osf.io/p5sbt/, identifier (10.17605/OSF.IO/P5SBT).

Prevalence and factors associated with hypertension in primary school children, in the centre region of Cameroon

BACKGROUND

There has been a progressive increase in hypertension among children and adolescents over the years. Hypertension in childhood is influenced by various risk factors including; childhood obesity, lifestyle and hereditary factors. This study is aimed at assessing the prevalence of hypertension and elevated blood pressure (BP); as well as the associated factors to hypertension among primary school children in a rural setting in the, Centre Region of Cameroon.

METHODS

A cross sectional study was carried out from November 2017 to May 2018 in 13 primary schools in Mbankomo subdivision. A two staged cluster sampling technique was used to select participants: the first stage we conveniently selected 13 out of 71 (18%) primary schools in the study area by probability proportionate to size since the subdivision does not have an equal number of primary schools in the rural and semi-urban areas. In the second stage, we also used probability proportional to size to randomly select participants from the 13 clusters because the classes did not have equal number of students. We randomly selected 13% pupils enrolled in each class of the 13 schools. BP and anthropometric measurements were taken, together with socio-demographic characteristics, lifestyle and past history.

RESULTS

The overall prevalence of hypertension among the 822 pupils sampled was 1.6% (with 1.5% in stage I and 0.1% in stage II) and that of elevated BP 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 and r=0.07; P=0.000 respectively) and BMI (r=0.18; P=0.000 and r=0.11; P=0.000 respectively). The associated risk factors for hypertension were: the pupil's age >10 years (95% CI: 1.2581-33.1841; P=0.0254), family history of overweight (95% CI: 1.6906-32.9401; P=0.008), and excess weight (95% CI: 2.5094-40.7063; P=0.0011), and being born at term (P=0.0004) as a protecting factor.

CONCLUSIONS

This study revealed a high prevalence of hypertension among primary school children in rural areas, with a number of preventable risk factors. Considering the risk factors found, children should be educated on proper nutrition, and the need for physical exercises at home and in school to avoid overweight and obesity.

Prevalence of elevated blood pressure in children and adolescents in Africa: a systematic review and meta-analysis

BACKGROUND

Despite substantial attention paid to the threat of elevated blood pressure in children and adolescents in high-income countries and the epidemic of hypertension in African adult populations, data on the burden of elevated blood pressure in African children and adolescents have not yet been synthesised. We did a systematic review and meta-analysis to provide estimates of the prevalence of elevated blood pressure and assess associated factors among children and adolescents in Africa.

METHODS

We searched Embase, PubMed, African Journals Online, and African Index Medicus to identify articles published from Jan 1, 1996, to Feb 2, 2017, and searched the reference list of retrieved articles. Each study was independently reviewed for methodological quality. We used a random-effects model to estimate the prevalence of elevated blood pressure across studies and heterogeneity (I²) was assessed via the χ² test on Cochran's Q statistic. This review is registered with PROSPERO, number CRD42015019029.

FINDINGS

We included 51 studies in qualitative synthesis and 25 in the meta-analysis reporting data of a pooled sample of 54 196 participants aged 2-19 years. Study quality was high with only four medium-quality studies and no low-quality studies. Prevalence of elevated blood pressure varied widely across studies (range 0·2-24·8%). The pooled prevalence of elevated blood pressure (systolic or diastolic blood pressure ≥95th percentile) was 5·5% (95% CI 4·2-6·9), whereas that of slightly elevated blood pressure (systolic or diastolic blood pressure ≥90th percentile and <95th percentile) was 12·7% (2·1-30·4). The prevalence of elevated blood pressure was largely associated with body-mass index (BMI), with a prevalence of elevated blood pressure six times higher in obese (30·8%, 95% CI 20·1-42·6) versus normal-weight children (5·5%, 3·1-8·4; p<0·0001).

INTERPRETATION

This study suggests a high prevalence of elevated blood pressure among children and adolescents in Africa, with overweight and obesity being an important risk factor. Efforts to address this burden of elevated blood pressure in children and adolescents should mainly focus on primary prevention at the community level, by promoting healthy lifestyles and avoiding other cardiovascular risk factors, especially overweight and obesity. This study also stresses the need for more elaborate studies using uniform and reliable diagnostic methods to reliably map the burden of elevated blood pressure in children and adolescents in Africa.

FUNDING

None.

Prevalence of Hypertension in Nigerian Children and Adolescents: A Systematic Review and Trend Analysis of Data from the Past Four Decades

Despite four decades of research, there is no systematic review and trend analysis on paediatric (pre)hypertension in Nigeria. This article reviewed data from cross-sectional studies on the subject. From the initial 9334 articles identified, 30 studies that met the inclusion criteria were systematically reviewed. Data from studies that defined hypertension as blood pressure (BP) greater than the 95th percentile for age, height and sex gave a prevalence of 8.2% [95% confidence interval (CI): 3.6-28.2%] for prehypertension and 5.1% (95% CI: 2.9-8.6%) for hypertension. For studies that defined hypertension as BP greater than 2 SD points from the mean of the population, the prevalence of hypertension was found to be 4.0% (95% CI: 2.8-5.7%). A significant negative trend (Z = -0.89; α < 0.01) with small magnitude (Q = -0.019; 95% CI: -0.070 to 0.028) was found for hypertension in the reviewed population. The prevalence of (pre)hypertension in Nigerian children and adolescents is moderate but has slightly declined over time.

High blood pressure and associated risk factors as indicator of preclinical hypertension in rural West Africa: A focus on children and adolescents in The Gambia

Hypertension is fast becoming a major public health problem across sub-Saharan Africa. We sought to determine the prevalence of high blood pressure (BP) and associated risk factors as indicator of preclinical hypertension in a rural Gambian population.We analyzed data on 6160 healthy Gambians cross-sectionally. Attention was given to 5 to <18-year olds (N = 3637), as data from sub-Saharan Africa on this young age group are scarce. High BP was defined as systolic blood pressure (SBP) above the 95th percentile for age-sex specific height z scores in <18-year olds employing population-specific reference values. Standard high BP categories were applied to ≥18-year olds.In <18-year olds, the multivariable analysis gave an adjusted high BP prevalence ratio of 0.95 (95% confidence interval [CI] 0.92-0.98; P = 0.002) for age and 1.13 (95% CI 1.06-1.19; P < 0.0001) for weight-for-height z score (zWT-HT); sex and hemoglobin were not shown to affect high BP. In adults age 1.05 (95% CI 1.04-1.05; P < 0.0001), body mass index z score 1.28 (95% CI 1.16-1.40; P < 0.0001), hemoglobin 0.90 (95% CI 0.85-0.96; P < 0.0001) and high fasting glucose 2.60 (95% CI 2.02-3.36; P < 0.0001, though the number was very low) were confirmed as risk factors for high BP prevalence; sex was not associated.The reported high BP prevalence and associated risk factors in adults are comparable to other studies conducted in the region. The observed high BP prevalence of 8.2% (95% CI 7.4-9.2) in our generally lean young Gambians (<18 years) is alarming, given that high BP tracks from childhood to adulthood. Hence there is an urgent need for further investigation into risk factors of pediatric high BP/hypertension even in rural African settings.

Overweight and obesity in children aged 3-13 years in urban Cameroon: a cross-sectional study of prevalence and association with socio-economic status

Background

Childhood overweight/obesity is increasing rapidly in developing countries. There is a need to provide more evidence on its burden in sub-Saharan Africa, and to identify associated factors in order to set preventive measures. We aimed to determine the prevalence of overweight/obesity and assess its association with the socioeconomic status in nursery and primary school children in urban Cameroon.

Methods

In this cross-sectional study, we included by multi-staged cluster random sampling 1343 children from high (HSES, n = 673) and low (LSES, n = 670) socioeconomic status schools in Douala. Parent/child demographic data were collected, and children’s anthropometric parameters were measured using validated methods. The World Health Organization body mass index-for-age reference curves were used.

Results

The prevalence of overweight/obesity was 12.5% (13.2% in girls, 11.8% in boys). The risk of overweight/obesity was 2.40 (95% CI 1.70, 3.40) higher in HSES children compared to LSES after adjusting for age and gender. However this association was attenuated to 1.18 (95% CI 0.59, 2.35) once adjustment had been made for a range of potential confounders.

Conclusions

Overweight/obesity is relatively common in sub-Saharan African children and prevalence is associated with HSES. However, this association may be mediated by sweet drink consumption, passive means of travel to school and not doing sport at school. We suggest that these potentially modifiable behaviors may be effective targets for obesity prevention. Further studies should specifically focus on unhealthy behaviors that mediate overweight/obesity as well as other non communicable diseases in children.

Electronic supplementary material

The online version of this article (doi:10.1186/s40608-017-0146-4) contains supplementary material, which is available to authorized users.

Burden of Hypertension and Abnormal Glomerular Permeability in Hypertensive School Children

Background

Childhood hypertension has been associated with target-organ damage in young adults. It is often asymptomatic in both children and adolescents; when persistent, and long-standing, it could be a significant risk factor for kidney damage and increased glomerular permeability.

Objectives

Burden of hypertension and its impact on glomerular permeability were prospectively determined in randomly recruited primary school children.

Patients and Methods

Blood pressure (BP) measurement was performed by the auscultation method, and abnormal glomerular permeability was assessed by dipstick testing of urine for persistent proteinuria and/or hematuria for ≥ three months in hypertensive children.

Results

Of 1,335 pupils aged 10.0 ± 2.4 (6.0 - 14.0) years, 33 (2.5%) were hypertensive. Overall mean systolic/diastolic BP was 125.6 ± 6.5/81.7 ± 3.3 (range: 114.0 - 140.0/80.0 - 90.0) mmHg. Nine (27.3%) had combined systolic and diastolic hypertension, 126.7 ± 5.7/80.0 - 80.0 ± 0.0 (120.0 - 130.0/80.0 - 80.0) mmHg. Isolated systolic hypertension, 125.4 ± 6.7 (114.0 - 140.0) mmHg, was present in 14 (42.4%), whereas 10 (30.3%) had isolated diastolic hypertension, 82.0 ± 3.5 (80.0 - 90.0) mmHg. Mean systolic and diastolic BP were 131.0 ± 3.3 (130.0 - 140.0) mmHg and 86.5 ± 4.43 (80.0 - 90.0) mmHg, respectively. According to the dipstick test, none of the hypertensive pupils showed urinalysis evidence of proteinuria and/or hematuria after three months of testing.

Conclusions

Although the burden of hypertension was 2.5%, the dipstick method did not detect any hypertension-related abnormal glomerular permeability in the school children.

Blood pressure tracking in urban black South African children: birth to twenty cohort

Background

Hypertension is an emerging public health problem in South Africa. Recent evidence from longitudinal studies has shown that hypertension in adulthood can be traced back to childhood. There is scarcity of longitudinal data on paediatric blood pressure (BP) particularly in African populations. The objective of this study is to assess the prevalence of hypertension and evaluate BP tracking between childhood and late adolescence among South African black Children.

Methods

This study utilized data from the Birth to Twenty cohort, which is comprised of children born in Soweto, Johannesburg in 1990 (N = 3273, 78.5 % black). Data on BP and anthropometry were collected at six follow-up periods between ages 5 and 18 years. Blood pressure status was classified using the Fourth report on National High Blood pressure program in children and adolescents. Pearson correlation coefficients and relative risk ratios (RR) were used to describe tracking of BP between childhood and late adolescence.

Results

The overall point prevalence ranged from 9.2 to 16.4 % for prehypertension and 8.4 to 24.4 % for hypertension. Tracking coefficients ranged from 0.20 to 0.57 for SBP and 0.17- 0.51 for DBP in both sexes over the 14 years of measurement. The proportion of children who maintained an elevated BP status between childhood, adolescence and age 18 years ranged from 36.1 % at age 5 years to 56.3 % at age 13 years. Risk of having elevated BP at 18 years ranged from; RR: 1.60 (95 % CI: 1.29–2.00) at 5 years to RR: 2.71 (95 % CI: 2.32–3.17) at 14 years of age.

Conclusions

This study reports high prevalence of elevated BP which tracks from early childhood into late adolescence. These findings emphasize the importance of early identification of children at risk of developing elevated BP and related risk factors plus timely intervention to prevent hypertension in adulthood.

Evidence of an overweight/obesity transition among school-aged children and youth in Sub-Saharan Africa: a systematic review

BACKGROUND

Prevalence of childhood overweight/obesity has increased considerably in recent years. The transition to higher rates of overweight/obesity has been well documented in high income countries; however, consistent or representative data from lower income countries is scarce. It is therefore pertinent to assess if rates of overweight/obesity are also increasing in lower income countries, to inform public health efforts.

OBJECTIVE

This systematic review aimed to investigate the evidence for an overweight/obesity transition occurring in school-aged children and youth in Sub Saharan Africa.

METHODS

Studies were identified by searching the MEDLINE, Embase, Africa Index Medicus, Global Health, Geobase, and EPPI-Centre electronic databases. Studies that used subjective or objective metrics to assess body composition in apparently healthy or population-based samples of children and youth aged 5 to 17 years were included.

RESULTS

A total of 283 articles met the inclusion criteria, and of these, 68 were used for quantitative synthesis. The four regions (West, Central, East, and South) of Sub Saharan Africa were well represented, though only 11 (3.9%) studies were nationally representative. Quantitative synthesis revealed a trend towards increasing proportions of overweight/obesity over time in school-aged children in this region, as well as a persistent problem of underweight. Weighted averages of overweight/obesity and obesity for the entire time period captured were 10.6% and 2.5% respectively. Body composition measures were found to be higher in girls than boys, and higher in urban living and higher socioeconomic status children compared to rural populations or those of lower socioeconomic status.

CONCLUSIONS

This review provides evidence for an overweight/obesity transition in school-aged children in Sub Saharan Africa. The findings of this review serve to describe the region with respect to the growing concern of childhood overweight/obesity, highlight research gaps, and inform interventions.

PROSPERO REGISTRATION NUMBER

CRD42013004399.