Somatotype and blood pressure of rural South African children aged 6–13 years: Ellisras longitudinal growth and health study

Abstract

Background: Physique has been useful in assessing the outcome of underlying growth and maturity processes, which leads to a better understanding of variation in child and adult health. However, a high endomorphy rating has been associated with hypertension in adults, posing a serious threat to their health status, while receiving little attention in children.

Aim: The study examined the association between somatotypes, body mass index (BMI) and blood pressure (BP) in 6–13-year-old rural children, in Ellisras, South Africa.

Subjects: A total of 1902 subjects (980 boys and 922 girls) aged 6–13 years were studied as part of the Ellisras Longitudinal Study. Height, weight, four skinfold sites, two breadths, and two girths were measured according to the International Society for the Advancement of Kinanthropometry (ISAK). The Heath–Carter method of somatotyping was used, together with internationally recommended cut-off points for BMI in children. Hypertension, defined as the average of three separate BP readings, where the systolic or diastolic BP is greater than or equal to the 95th percentile for age and sex, was determined.

Results: The prevalence of hypertension ranges from 1 to 5.8% in boys and 3.4–11.4% in girls. The prevalence of overweight ranges from 1.1 to 2.9% in boys and 0.6–4.6% in girls. Systolic BP and BMI showed a significant positive correlation at age 6 years (r = 0.436) and 10–13 years (r = 0.180–0.246 in boys and r = 0.221–0.271 in girls). Diastolic BP showed an insignificant correlation with the BMI and somatotype components in boys and girls.

Conclusion: A significant association exists between BP and BMI, and ectomorphy components even after being adjusted for age, gender and height. The need to manage hypertensive individuals is evident in this sample to combat this chronic disease from an early age. Follow-up studies should investigate the relationship between BP and the dietary intake of these children.