Effect of BMI and Its Optimal Cut-Off Value in Identifying Hypertension in Uyghur and Han Chinese: A Biethnic Study from the China National Health Survey (CNHS)

Objective. The effect of adiposity on hypertension among Uyghur Chinese is not clear. This study aimed to compare the effect of BMI and its optimal cut-off value in identifying hypertension in Uyghur and Han adults in China. Methods. By using a multistage stratified sampling method, 3072 Uyghur and 3195 Han adults underwent questionnaire interview, physical examination, and biochemical tests. Age-and sex-standardized prevalence of hypertension was calculated. Adjusted odds ratios for adiposity associated with hypertension were estimated. ROC analyses were used for assessing the ethnic and sex specific optimal BMI cut-off values in identifying hypertension. Results. Both in Uyghur and Han, increased BMI was consistent with the elevated systolic and diastolic blood pressure. Although more Uyghur were overweight/obese, their standardized prevalence of hypertension (17.87%) was lower than that of Han (20.28%). Han adults had 1.42 times odds than Uyghur of hypertension. The adjusted ORs of overweight and obesity were 2.67 and 6.04 in Uyghur and 2.74 and 7.58 in Han. In male, the optimal cut-off values of BMI identifying hypertension in Uyghur and Han were 24.6 kg/m(2) and 24.9 kg/m(2), respectively, but the correspond values in Uyghur and Han females were 27.2 kg/m(2) and 25.0 kg/m(2). Conclusions. Adiposity had strong effect on hypertension, but this effect was less strong in Uyghur female than in Han female.