ABSTRACT
Objective To explore the associations of body mass index (BMI), waist circumference (WC), waist height ratio (WHtR) and the prevalence of hypertension in elderly residents over 60 years in Baodi district, Tianjin. Methods Residents over 60 who underwent medical examinations in the Koudong Health Center, Baodi district, Tianjin, were all invited to participate in the study from April to May, 2018. Participants were asked to fill out structured questionnaires and undergo physical examinations. Stratified analysis and logistic regression analysis were applied to examine joint effects and interactions of BMI and WC (or WHtR) on the risk of hypertension. Results A total of 1 417 residents (83.75%) out of 1 692 residents participated in the study. The prevalence of hypertension in the participants was 46.36%. 66.50% of the participants were BMI overweight or obese. Participants with central obesity accounted for 74.66% (measured by the WC) and 75.38% (by the WHtR). Compared to the normal weight measured by the BMI or the WC, BMI overweight (OR=1.65, 95%CI: 1.19-2.30) or obesity (OR=3.41, 95%CI: 2.23-5.20) and WC central obesity (OR: 1.49, 95%CI: 1.00-2.23) were associated with increased risk of hypertension. The joint effects of BMI and WC (OR=2.49, 95%CI: 1.78-3.46), or BMI and WHtR (WHtR overweight: OR=2.05, 95%CI: 1.41-2.99; WHtR obesity: OR=2.37, 95%CI: 1.50-3.76) were greater than the single effect of the latter (WC overweight/obesity: OR=1.39, 95%CI: 0.90-2.15; WHtR overweight: OR=1.02, 95%CI: 0.62-1.66; WHtR obesity: OR=1.44, 95%CI：0.55-3.81). Conclusions Of the three indices, BMI is strongly correlated with the risk of hypertension. BMI overweight or obesity has enhanced the association of WC or WHtR and the risk of hypertension, suggesting that weight control in the normal range, especially measured by the BMI index, may prevent and control hypertension.