Objective To investigate the prevalence of hypertension

overweight

obesity

and central obesity rates in adults in Tongnan district

so as to explore the relationship between body mass index（BMI）

waist circumference

and the risk of hypertension. Methods A total of 2 618 subjects were enrolled in this study based on the natural cohort study in southwestern China. The methodology included a questionnaire survey and physical examination. The detection rate of hypertension was calculated for subjects with different BMI and waist circumferences. The association between BMI

waist circumference

and hypertension was analyzed and investigated. Results The prevalence of hypertension was 31.02%

the overweight rate

32.29%; the obesity rate

10.61%; and the central obesity rate

24.86%. The risk of hypertension was 1.40 times higher in people with overweight and obesity combined with normal waist circumference; 1.02 times higher in people with normal BMI and central obesity; and 1.53 times higher in people with overweight and obesity combined with central obesity. The follow-up data showed that the risk of hypertension was significantly increased in obese/overweight people

those who changed from overweight to obese people

and those who changed from normal BMI to overweight/obese people during the follow-up period compared with those who remained normal BMI（P<0.05）. While the risk of hypertension in those who changed from overweight/obese to normal BMI was not significantly different from that in subjects whose BMI remained normal. Conclusion The simultaneous increase of BMI and waist circumference increases the risk of hypertension in the population

and its combined effect is greater than that of the two alone.