The prevalence of hypertension and the relationship with body composition in Grade 1 learners in the North West Province of South Africa

Abstract

Objective. To determine the prevalence of hypertension in Grade 1 learners in the North West Province of South Africa and to investigate the association between blood pressure (BP) and body composition of these children. Methods. Data were collected by means of a stratified random sampling procedure from 816 Grade 1 learners (419 boys, 397 girls) with a mean age of 6.78±0.49 years (mean±SD), in the NWCHILD-study. Height, weight, skinfolds (subscapular, triceps, calf) and waist circumference were measured. The international recommended cut-off values of Cole et al. (2000) for body mass index (BMI) were used. Hypertension, defined as the average of two separate BP (BP) readings, where the systolic BP and diastolic BP is >95th percentile for age, sex and height, was determined by means of an Omron 705CP-II. Results. The overall prevalence of prehypertension and hypertension was 8.5% and 24.9%, respectively. Both systolic and diastolic BP was positively associated with BMI, body fat percentage and waist circumference. Boys and girls showed a similar prevalence of hypertension. A higher percentage of black children were hypertensive compared with whites, although the difference in BP of the groups was not significant. A high percentage of children with normal weight also showed increased levels of BP. Conclusions. High prevalences of hypertension were found in Grade 1 learners in the North West Province of South Africa. Small practical significant associations existed between BP and body composition. BP screening is therefore considered important in the paediatric population. Interventions which include physical activity are recommended to reduce potential cardiovascular complications and obesity among children. Other contributing factors to high BP amongst young children should also be investigated.SAJSM, vol 23 No. 4 2011