Association of normal-weight central obesity with hypertension: a cross-sectional study from the China health and nutrition survey

BACKGROUND: Central obesity is associated with an increased risk of hypertension in the general population. However, little is known regarding the potential relationship between central obesity and the risk of hypertension among adults with a normal body mass index (BMI). Our aim was to assess the risk of hypertension among individuals with normal weight central obesity (NWCO) in a large Chinese population. METHODS: We identified 10 719 individuals aged 18 years or older from the China Health and Nutrition Survey 2015. Hypertension was defined by blood pressure measurements, physician diagnosis, or the use of antihypertensive treatment. Multivariable logistic regression was used to assess the association of obesity patterns, defined by BMI, waist circumference (WC) and waist hip ratio (WHR), with hypertension after adjusting for confounding factors. RESULTS: The patients' mean age was 53.6 ± 14.5 years, and 54.2% were women. Compared with individuals with a normal BMI but no central obesity, subjects with NWCO had a greater risk of hypertension (WC: OR, 1.49, 95% CI 1.14-1.95; WHR: OR, 1.33, 95% CI 1.08-1.65). Overweight-obese subjects with central obesity demonstrated the highest risk of hypertension after adjustment for potential confounders (WC: OR, 3.01, 95% CI 2.59-3.49; WHR: OR, 3.08, CI 2.6-3.65). Subgroup analyses showed that the combination of BMI with WC had similar findings to the overall population except for female and nonsmoking persons; when BMI was combined with WHR, a significant association of NWCO with hypertension was observed only in younger persons and nondrinkers. CONCLUSIONS: Central obesity, as defined by WC or WHR, is associated with an increased risk of hypertension in Chinese adults with normal BMI, highlighting the need to combine measures in obesity-related risk assessment.