Body mass index compared with abdominal obesity indicators in relation to prehypertension and hypertension in adults: the CHPSNE study

Background Debate ensues regarding the stronger indicator of obesity, body mass index (BMI), or waist circumference (WC), in association with hypertension. Furthermore, little research has been done to compare BMI and WC in their associations with prehypertension. Methods A cross-sectional survey was undertaken in 33 communities randomly selected from 3 cities in Northeastern China during 2009-2010, using a total of 25,196 adults aged 18-74 years with an overall response rate of 87.4%. Diagnoses of prehypertension and hypertension were based on the criteria set by the Seventh Report of the Joint National Committee. Generalized overweight and obesity were defined as BMI 25-29.9 and ≥30 kg/m(2), respectively. Abdominal overweight and obesity were defined as WC 94-102 and >102 cm in men and WC 80-88 and >88 cm in women, respectively. Results Both BMI and WC were positively related to the prevalence rate of elevated blood pressure. Among younger individuals, aged 18-44 years, WC seemed to be associated with a higher odds ratio (OR) than BMI for hypertension (e.g., for men, 17.18 (BMI) vs. 23.28 (WC) for obesity), in contrast, BMI seemed to be associated with a higher OR than WC for prehypertension (e.g., for men, 5.99 (BMI) vs. 1.51 (WC) for obesity). Among older individuals, aged ≥45 years, the adjusted OR for hypertension was modestly higher for WC than for BMI in men. In women, the adjusted OR was modestly higher for BMI than for WC. Conclusions In this Chinese population, the association of body fat and abdominal fat with hypertension and prehypertension depends on age and sex.