Does Moderate Drinking Increase the Risk of Atrial Fibrillation? The Norwegian HUNT (Nord‐Trøndelag Health) Study

Background Compelling evidence suggests that excessive alcohol consumption increases the risk of atrial fibrillation ( AF ), but the effect of light‐moderate alcohol consumption is less certain. We investigated the association between alcohol consumption within recommended limits and AF risk in a light‐drinking population. Methods and Results Among 47 002 participants with information on alcohol consumption in a population‐based cohort study in Norway, conducted from October 2006 to June 2008, 1697 validated AF diagnoses were registered during the 8 years of follow‐up. We used Cox proportional hazard models with fractional polynomials to analyze the association between alcohol intake and AF . Population attributable risk for drinking within the recommended limit (ie, at most 1 drink per day for women and 2 drinks per day for men without risky drinking) compared with nondrinking was also calculated. The average alcohol intake was 3.8±4.8 g/d. The adjusted hazard ratio for AF was 1.38 (95% confidence interval, 1.06–1.80) when we compared participants consuming >7 drinks per week with abstainers. When we modeled the quantity of alcohol intake as a continuous variable, the risk increased in a curvilinear manner. It was higher with heavier alcohol intake, but there was virtually no association at <1 drink per day for women and <2 drinks per day for men in the absence of risky drinking. The population attributable risk among nonrisky drinkers was 0.07% (95% confidence interval, −0.01% to 0.13%). Conclusions Although alcohol consumption was associated with a curvilinearly increasing risk of AF in general, the attributable risk of alcohol consumption within recommended limits among participants without binge or problem drinking was negligible in this population.