Alcohol and risk of atrial fibrillation or flutter: a cohort study.

BACKGROUND The evidence for an association between alcohol consumption and risk of atrial fibrillation is conflicting. METHODS We prospectively examined the association between alcohol consumption and risk of atrial fibrillation or flutter among 47 949 participants (mean age, 56 years) in the Danish Diet, Cancer, and Health Study. The consumption of alcohol was analyzed as sex-specific quintiles by Cox proportional hazards regression models. RESULTS The mean +/- SD consumption of alcohol per day was 28.2 +/- 25 g in men and 13.9 +/- 15 g in women. During follow-up (mean, 5.7 years), atrial fibrillation or flutter developed in 556 subjects (374 men and 182 women). After adjusting for established risk factors, there was a modest increase in risk of atrial fibrillation or flutter by increasing alcohol consumption in men. When using the lowest quintile of alcohol consumption in men as a reference, the adjusted hazard rate ratios in men in quintiles 2, 3, 4, and 5 were 1.04, 1.44, 1.25, and 1.46, respectively (P for trend, .04). When using the lowest quintile of alcohol consumption in women as a reference, the adjusted hazard rate ratios in women in quintiles 2, 3, 4, and 5 were 1.09, 1.27, 1.23, and 1.14, respectively (P for trend, .69). Inclusion of information on the frequency of alcohol consumption and the preferred source of alcohol did not change these associations. CONCLUSIONS Consumption of alcohol was associated with an increased risk of atrial fibrillation or flutter in men. In women, moderate consumption of alcohol did not seem to be associated with risk of atrial fibrillation or flutter.