Background: Alcohol exposure is one of the major risk factors for global burden of disease, but atrial fibrillation (AF) had not yet been included in these estimates. The purpose of this contribution was to examine the dose–response relationship between alcohol consumption and AF and to explore potential causal pathways.
Design and methods: Systematic literature review and meta-analyses.
Results: Overall, a consistent dose–response relationship between the amount of alcohol consumed daily and the probability of the onset of AF was found. Women consuming 24, 60 and 120 g of alcohol daily had relative risks of 1.07 [95%confidence interval (CI): 1.04–1.10], 1.42 (95% CI: 1.23–1.64) and 2.02 (95% CI: 1.60–2.97), respectively, relative to nondrinkers. Among men, the corresponding relative risks were 1.08 (95% CI: 1.04–1.11), 1.44 (95% CI: 1.23–1.69) and 2.09(95% CI: 1.52–2.86). Based on the categorical analyses, we could not exclude the existence of a threshold (three drinks a day for men and two drinks a day for women). Several pathogenic mechanisms for the development of AF in alcohol users were identified.
Conclusion: Epidemiological criteria for causality were met to conclude a causal impact of alcohol consumption on the onset of AF with a monotonic dose–response relationship. However, the impact of light drinking is not clear.
Keywords: alcohol; atrial fibrillation; cardiac rhythm disorders; causality; heavy drinking.