Interaction effect between overweight/obesity and alcohol consumption on hypertension risk in China: a longitudinal study

OBJECTIVE: To explore the interaction effect between overweight/obesity and alcohol consumption on hypertension risk. DESIGN: A longitudinal study of the independent and combined effects of hypertension risk factors. SETTING: Twelve provinces in China, including Beijing Liaoning, Heilongjiang, Shanghai, Jiangsu, Shandong, Henan, Hubei, Hunan, Guangxi, Guizhou and Chongqing. PARTICIPANTS: Longitudinal data of China Health and Nutrition Survey, collected between 2011 and 2015, were used in this study. A total of 13 121 residents from 12 provinces were included and completed physical examinations and questionnaires at baseline. OUTCOME: First incidence of hypertension. RESULTS: Over a mean follow-up of 4 years, 690 incident hypertension cases were reported. After adjusting for age, gender, education level, marital status, physical activity, diabetes and smoking, high body mass index (BMI) and light drinking (OR=5.07, 95% CI 3.06 to 8.41), high waist circumference (WC) and light drinking (OR=4.81, 95% CI 2.92 to 7.91), high waist hip ratio and light drinking (OR=2.85, 95% CI 1.84 to 4.42) were the highest risk of all participants in the three combinations. Multiplicative interaction measures were statistically significant in overweight/obesity and drinking/light drinking/heavy drinking categories in men (p<0.05). Additive interactions were observed between high BMI and drinking in men (relative excess risk due to interaction=1.75, 95% CI 0.85 to 2.65, attributable proportion due to interaction=0.56, 95% CI 0.36 to 0.76, synergy index=6.43, 95% CI 1.02 to 28.84). CONCLUSIONS: Measures of body weight and size, particularly BMI and WC, appear to interact synergistically with alcohol consumption to increase the risk of hypertension in the Chinese population. Given that approximately 245 million people in China have hypertension, and that hypertension is a major cause of cardiovascular disease worldwide, our results may have implications for chronic disease prevention.