Blood pressure among overweight children aged 7-13 years in 10 rural communities in South Africa: The Tshannda Longitudinal Study

Objectives: This study examined the incidence of hypertension among South African rural children involved in the Tshannda Longitudinal Study. This cross-sectional study comprised of 409 children (193 boys and 216 girls) of grades 1-7 from primary schools in Tshannda, Vhembe District, South Africa. It forms Phase 1 of the Tshannda Longitudinal Study. Methodology: Stature and body mass were measured using standard procedures. Blood pressure (BP) was monitored for three consecutive times using validated electronic devices (Omron 7051T). Hypertension was determined as the average of three separate BP readings where the systolic or diastolic BP was 95th percentile for age and sex. Results: The incidence of overweight defined by body mass index (BMI) cutoff was 2.6% for boys and 2.9% for girls. The likelihood of the development of hypertension among the children is noticeable at grade level one for both boys and girls (1.7% and 1.3% respectively) and ranged from 0.3% to 1.7% for boys and 1.3% to 5.2% for girls. Overall, the incidence of hypertension was 1.5% and 1.8% in boys and girls, respectively. Blood pressure correlated positively with stature, body mass, BMI and body fat (p = 0.00). Conclusions: The findings demonstrate the need for routine measurement of BP as part of physical examination in school children and use of cutoffs tailored to metabolic risks may be essential for assessment of overweight.