Utility of Obesity Indicators for Predicting Hypertension among Older Persons in Limpopo Province, South Africa

Abstract

In view of the epidemic proportions of obesity in South Africa and its relationship to cardiometabolic diseases, such as hypertension, a cross sectional study was conducted to investigate the utility of obesity indicators for predicting hypertension among older persons (≥60 years, n = 350) in the Limpopo Province of South Africa. The WHO STEPwise approach was used to collect data on demographic and lifestyle factors. Anthropometrics and blood pressure were measured according to the standard procedures. Receiver operating characteristic curves (ROC) were used to investigate and compare the ability of obesity indicators to predict overall hypertension and either increased systolic (SBP) or increased diastolic (DBP) blood pressure. The area under the ROC curve (AUC) was used to assess a certain indicator’s potential to predict overall hypertension and either increased SBP or increased DBP. Multivariate logistic regression analysis was used to determine the relationship of hypertension with obesity indicators. The mean age of the participants was 69 years (±SD = 7), and hypertension (46%), general obesity (36%) and abdominal obesity (57%) were prevalent among older persons. The obesity indicator body mass index (BMI) (AUC = 0.603 (0.52; 0.69)) was the best predictor of hypertension in older men. Waist circumference (WC) (AUC = 0.640 (0.56; 0.72)) and waist-to-height ratio (WHtR) (AUC = 0.605 (0.52; 0.69)) were better predictors of hypertension than BMI and waist-to-hip ratio (WHR) in older women. After adjustment for risk factors, only WC (AOR = 1.22 (1.16; 1.79)) was significantly associated with hypertension in older women, proposing WC as a screening tool for the prediction of hypertension in South African older women.