Interaction Between Body Mass Index and Alcohol Intake in Relation to Blood Pressure in HAN and SHE Chinese

Background Blood pressure (BP) increases with body mass index (BMI) and excessive alcohol intake. Few epidemiologic studies explored the interaction between BMI and alcohol intake in relation to BP. Methods We randomly selected 10 villages with a mixed population of HAN and SHE Chinese in the JingNing County in Southeast China. We measured BP, anthropometric characteristics, and alcohol intake in 1688 participants. Our statistical methods included single and multiple linear and logistic regressions. Results HAN (n = 520) and SHE (n = 1168) had a similar sex and age distribution. SHE Chinese, compared with HAN, had a higher BP (128.0/79.7 v 121.5/76.9 mm Hg, P< .001), and more frequently reported alcohol intake (45.0% v 27.7%; P< .001), but showed lower BMI (22.2 v 22.5 kg/m2; P = .05) and waist-to-hip ratio (0.83 v 0.87; P< .001). In SHE, but not HAN, there was a significant interaction (P< .01) between BMI and alcohol intake in relation to BP. In SHE with BMI < 25 kg/m2, BP was significantly higher in drinkers than nondrinkers (129.4/80.2 v 124.2/77.4 mm Hg, P< .001), whereas among SHE with BMI ≥25 kg/m2, BP was not associated with alcohol intake (134.3/84.9 v 136.8/85.7 mm Hg, P> .41). Accordingly, in SHE Chinese, the slope of BP associated with BMI was less steep (P< .01) in drinkers than nondrinkers. Conclusions Among SHE Chinese, alcohol intake and BMI interactively influenced BP. Further research is required to elucidate the underlying mechanism.