The association of obesity, somatotype and high salt intake with hypertension among adults in Lephalale, South Africa: Ellisras Longitudinal Study

Abstract

Hypertension has emerged as a significant public health concern, and has been primarily associated with obesity, high salt intake as well as somatotype. This study aimed to assess the association of obesity, defined by body mass index (BMI), high salt intake and somatotype with hypertension amongst adults in Lephalale (formerly known as Ellisras) rural area, and to evaluate which of the three variables is the best predictor of hypertension. The dietary consumption of salt was determined using a 24-hour recall questionnaire. This cross-sectional study consisted of 739 (men, n = 370; mean age: 23.72 ± 2.02 years; women, n =362; mean age: 23,86 ± 2.04 years) participants, aged 21–29 years. Blood pressure (BP) and anthropometric measurements were done in accordance with standard procedures. The prevalence of obesity, somatotype, high salt intake, and high BP was determined using frequency analysis. Linear regression models were performed to determine the relationship between obesity, somatotype, and salt intake with BP, and the receiver operating curve (ROC) used to determine the best predictor of hypertension. The prevalence of high systolic BP was significantly (p<0.001) higher for males (13%) than females (1.7%). A significant (p<0.015) association between diastolic BP and salt intake (Beta= 7.86 95% CI: 1.87 − 13.85) was noted even after adjusting for age and gender (Beta = 7.24 95% CI: 1.38 − 13.10). A substantial (p<0.037) negative association between BMI and diastolic BP (Beta = -2.57 95% CI: -5.00 – -0.149) was evident when adjusted for gender and age. Sodium intake was significantly (p<0.05) associated with diastolic BP, but not systolic BP in the study sample. The receiver operating characteristics (ROC) analysis showed that obesity was a better predictor of hypertension thansomatotype variables and salt intake. Future longitudinal studies are needed to validate the present findings.