A Non-Invasive Investigation into the Prevalence of Higher than Normal Blood Pressure, Hypertension and the Association between Blood Pressure and Body Weight in Male and Female Adolescents in the Polokwane Local Municipality, Limpopo-South Africa: A Cross-Sectional Study

Background: Hypertension (HT) is one of the greatest non-communicable diseases affecting both sexes in all human populations; and it is a major cause of death and morbidity across the world. The purpose of this study was to investigate the prevalence of pre-hypertension, hypertension and investigate the association between blood pressure (BP) and body weight (looking into body mass index (BMI) and body surface area (BSA)). Method: A cross-sectional study of adolescents aged 13–19 years was conducted at three secondary schools consisting of 121 females and 97 males. Data on height; weight; and blood pressure was collected from all participants. BMI and BP percentiles were calculated for each participant. Results: The prevalence of pre-hypertension and hypertension in males was 28.9% and 10.3% compared to 25.6% and 7.4% in females. The prevalence of pre-hypertension and hypertension in adolescents who are overweight/obese was 7.3% and 2.7%. A weak positive association between BMI; systolic blood pressure (SBP) and diastolic blood pressure (DBP) was found (r = 0.254 and 0.216; p-value = 0.001) for the whole population. A significant, moderate correlation was found between BSA on SBP was found (r = 0.407, p-value = 0.001); and a significant, weak correlation between BSA and DBP was found (r = 0.183, p-value = 0.007. In conclusion, the prevalence of pre-hypertension and hypertension was higher in males as compared to females. Results highlight the need for screening for blood pressure and body weight in adolescents; especially in adolescents who were found to have pre-hypertension as they are at high risk of developing hypertension.