Sex Differences in Impacts of Alcohol Consumption on Prevalent Atrial Fibrillation

High levels of alcohol consumption are a well-established risk factor for atrial fibrillation (AF). Although women currently tend to regulate alcohol intake more strictly than men, it remains unclear whether alcohol consumption should be regulated differently between sexes to prevent AF. This study investigated sex differences in alcohol-related AF risk.

Among 224 759 admissions in the Inpatient Clinico-Occupational Database of the Rosai Hospital Group (ICOD-R) from 32 hospitals across Japan in 2021, 123 852 participants were included. Using this cross-sectional dataset based on information collected at the time of hospital admission, associations between prevalent AF and alcohol consumption data, including drinking frequency, daily average drinks, and lifetime total alcohol intake, were investigated in women and men.

Women comprised 49% of participants; 3.7% had prevalent AF. Frequent drinking (≥ 4 days/week), high daily intake (≥ 2 drinks/day), and high lifetime consumption (≥ 65 drink-years) were associated with increased prevalent AF in both sexes. In men, low daily intake (< 2 drinks/day) (OR 1.21, 95% CI 1.09-1.34) and low lifetime consumption (< 65 drink-years) (OR 1.22, 95% CI 1.10-1.36) were linked to prevalent AF, but not in women. Significant sex interactions were observed in the association between alcohol intake and prevalent AF (drinking frequency: p = 0.035; lifetime total intake: p = 0.004).

This large-scale study did not find that men had a lower risk of prevalent AF at lower levels of alcohol consumption compared to women. The more lenient alcohol consumption limits currently applied to men, relative to women, may warrant reconsideration.