Relationship between obesity and blood pressure in school-going adolescents in the Limpopo province of South Africa

Hypertension and obesity are increasingly becoming a common problem among adolescents in South Africa. The aim of this study is to assess the relationship between obesity and hypertension in school-going adolescents in Limpopo, South Africa. A total of 1114 school-going black Africa adolescents (505 boys and 609 girls) were randomly selected from grades 7 to 12. Obesity was measured using body mass index (BMI), waist circumference (WC) and hip circumference (HC). Bivariate analysis SBP showed a significant positive association with age, BMI, HC and WC in boys (p < 0.05), and with only WC in girls while HC was marginally significant (p = 0.060). DBP showed a significant increase with age, BMI and WC in both sexes, including HC in girls. The odds of being hypertensive were associated with increase in BMI and HC in boys and with WC and WHR in girls. In the multivariate analysis age showed a significant positive association with SBP and DBP in boys (p = 0.001), and SBP with WC in girls (p = 0.049). The odds of being hypertensive increased significantly with BMI in boys (p = 0.015), and HC in girls (p = 0.042). The study confirmed that among school-going adolescent boys and girls increase in elevated BP is related to increase in body weight as measured by the selected anthropometric parameters. Blood pressure monitoring as part of school health programme may be useful for risk assessment and promotion of preventive measures.