A cross sectional study on the predictive value of body mass index and waist circumference for the risk of hypertension and diabetes of the residents in Xuzhou City

Objective To explore the optimal cut-off points of body mass index(BMI)and waist circumference(WC)in predicting hypertension, diabetes, and the risk of diseases at different status of BMI and WC. Methods With the multistage randomized cluster sampling, questionnaire survey and physical examination were carried out among 2 246 permanent residents aged 18 years and over in 11 communities of Quanshan, Xuzhou. Receiver operating characteristic curves(ROC)were used to calculate the optimal cut-off points of BMI and WC in detecting hypertension and diabetes. Non-conditional logistic regression was used to analyze the association of the risk of hypertension and diabetes with different status of BMI and WC. Results The rates of overweight, obesity based on BMI and central obesity in 2 246 subjects were 37.3%, 9.2%, and 44.9% respectively. The optimal cut-off points of BMI in predicting hypertension and diabetes were 24.6 and 26.1 kg/m2 in men, and 23.7 and 23.6 kg/m2 in women, respectively. The optimal cut-off points of waist circumference in predicting hypertension and diabetes were 84.8 and 89.9 cm in men, and 78.1 and 78.1 cm in women, respectively. After adjusting for potential confounding factors, comparing with normal subjects, the risks of hypertension were 1.529(95%CI 1.047-2.234), 2.386(95%CI 1.744-3.263), and 3.755(95%CI 2.506-5.627)in central obesity subjects with normal weight, overweight, and obesity based on BMI, and 1.813(95%CI 1.271-2.586)in obese subjects with normal WC. Comparing with normal subjects, the risks of diabetes were 2.282(95%CI 1.225-4.252), 2.964(95%CI 1.741-5.044), and 3.900(95%CI 2.077-7.322)in central obesity subjects with normal weight, overweight, and obesity based on BMI, and 5.016(95%CI 1.474-17.068)in obese subjects with normal WC. Conclusion The optimal cut-off points of BMI and WC in predicting the risk of diabetes were greater than those for hypertension in men, and similar in predicting diabetes and hypertension in women. The risk of hypertension in central obesity population was increased with the increase of BMI. WC showed greater impact on blood pressure compared with BMI. (Chin J Endocrinol Metab, 2016, 32: 803-807) Key words: Body mass index; Waist circumference; Hypertension; Diabetes