Ethnic diversity among Chinese in the association between blood pressure, body-mass index and alcohol intake

Abstract

Few studies explored to what extent ethnicity might impact on the role of obesity and alcohol intake as risk factors for hypertension. While adjusting for covariates, we investigated in a cross-sectional study whether the relations between blood pressure (BP), body-mass index (BMI) and alcohol intake were consistent among HAN and SHE Chinese living together in the JingNing County, 300 miles south of Shanghai. The 1688 study participants were inhabitants of 10 randomly selected villages. HAN (n=520) and SHE (n=1168) had a similar sex and age distribution, but SHE had a higher BP (128.0/79.7 vs 121.5/76.9 mm Hg, P<0.001), more frequently reported alcohol intake (45.0 vs 27.7%, P<0.001), and had a lower BMI (22.2 vs 22.5 kg/m2; P=0.05). In multivariate analyses adjusted for sex, age and current smoking, we found significant interaction (P<0.05) of alcohol intake and BMI with ethnicity in relation to BP in men and women, respectively. In HAN, the association between BP and BMI was independent of drinking habits, whereas in SHE alcohol intake and BMI jointly (P<0.01) influenced BP. In SHE with normal weight (BMI <25 kg/m2; 84.5%), BP was significantly higher in drinkers than non-drinkers (129.4/80.2 vs 124.2/77.4 mm Hg; P<0.0005), whereas among overweight SHE (BMI ≥25 kg/m2; 15.5%), BP was not associated with alcohol intake (134.3/84.9 vs 136.8/85.7 mm Hg; P>0.41). In conclusion, ethnicity impacts on the role of obesity and alcohol intake in the pathogenesis of hypertension. Preventive and therapeutic strategies focusing on lifestyle must account for ethnic diversity.