Causal associations of alcohol consumption with cardiovascular diseases and all-cause mortality among Chinese males

Background The causal effects of moderate alcohol consumption on cardiovascular diseases (CVDs) are continuously debated, especially on coronary artery disease (CAD). Objectives We aimed to explore the causal associations of alcohol consumption with CVDs and all-cause mortality among Chinese males. Methods A prospective cohort study was conducted in 40,386 Chinese males, with 17,676 being genotyped for the rs671 variant in the aldehyde dehydrogenase 2 (ALDH2 ) gene. A Cox proportional hazards model was conducted to estimate the effects of self-reported alcohol consumption. Mendelian randomization (MR) analysis was performed to explore the causality using rs671 as an instrumental variable. Results During the follow-up of 303,353 person-years, 2406 incident CVDs and 3195 all-cause mortalities were identified. J-shaped associations of self-reported alcohol consumption with incident CVD and all-cause mortality were observed, showing decreased risks for light (<= 25 g/d) and moderate drinkers (25-<= 60 g/d). However, MR analyses revealed a linear association of genetically predicted alcohol consumption with the incident CVD (P-trend = 0.02), including both CAD (P-trend = 0.03) and stroke (P-trend = 0.02). The HRs (95% CIs) for incident CVD across increasing tertiles of genetically predicted alcohol consumption were 1 (reference), 1.18 (1.01, 1.38), and 1.22 (1.03, 1.46). After excluding heavy drinkers, the risk of incident CVD and all-cause mortality was increased by 27% and 20% per standard drink increment of genetically predicted alcohol consumption, respectively. Conclusions Our analyses extend the evidence of the harmful effect of alcohol consumption to total CVD (including CAD) and all-cause mortality, highlighting the potential health benefits of lowering alcohol consumption, even among light-to-moderate male drinkers.