Background: Evidence regarding the relationship between different levels of alcohol consumption and the risk of atrial fibrillation (AF) is currently limited in Asian populations.
Methods and results: Between 1991 and 1995, a total of 8,602 Japanese men and women aged 30-80 years took part in the first examination of the Circulatory Risk in Communities Study (CIRCS), a population-based cohort study in Japanese communities. An interviewer obtained detailed information on weekly alcohol intake. During the follow-up period, the incidence of AF was ascertained from annual ECG records, the subject's medical history of AF, and cardiovascular disease surveillance. The hazard ratios (HRs) of incident AF and the 95% confidence intervals (CIs) relative to the never-drinking group were calculated with adjustment for potential confounding factors by using the Cox proportional hazard model. During a median follow-up period of 6.4 years, 296 incidents of AF occurred. A higher incidence of AF was observed among participants with an ethanol intake >69g/day, compared with never-drinkers. Compared with the never-drinkers, the multivariable-adjusted HRs (CIs) of past, light (<23g/day), light-moderate (23-46g/day), moderate (46-69g/day), and heavy (>69g/day) drinkers were 1.30 (0.68-2.49), 0.89 (0.60-1.32), 1.19 (0.73-1.95), 1.36 (0.79-2.35), and 2.90 (1.61-5.23), respectively.
Conclusions: Heavy alcohol consumption is associated with a higher risk of AF.