Background—
Evidence on the relationship of a wide range of alcohol consumption with risk of incident atrial fibrillation has been limited.
Methods—
Between 1991 and 1995, 8602 Japanese men and women aged 30 to 80 years and free of clinical atrial fibrillation took part in the first examination of the Circulatory Risk in Communities Study(CIRCS)- a population based cohort study of cardiovascular risk factors, cardiovascular disease incidence, and their trends in Japanese communities. In the first examination, we checked a detailed medical history, physical examination, blood and urine examination, and electrocardiogram (ECG). An interviewer obtained histories in detail for weekly alcohol intake. In the follow-up period, incident atrial fibrillations were ascertained by annual ECG record and medical history of treatment of atrial fibrillation. ECGs were coded with the Minnesota Code by trained physician-epidemiologists. Differences in baseline characteristics between atrial fibrillation cases and controls were compared using Student t-tests or chi-squared tests. The hazard ratios (HRs) of incidence of atrial fibrillation and 95% confidence interval (CI) relative to the never-drinking group were calculated with adjustment for age and other potential confounding factors using the Cox proportional hazard model.
Results—
During an average follow-up of 6.4 years, 290 incident atrial fibrillation occurred. The higher incidence rate of atrial fibrillation was observed among participants with more than 69 g of ethanol drinking per week, compared with less than 69 g of ethanol drinking per week. On the other hand, light to moderate alcohol consumption was not associated with risk of atrial fibrillation. Compared with the never drinking group, the multivariable-adjusted HRs of past, light (<23 g), light moderate (23-46 g), moderate (46-69 g), and heavy (>69 g) drinking groups were 1.20 (95% CI, 0.61-2.35), 0.85 (95% CI, 0.57-1.27), 1.05 (95% CI, 0.63-1.75), 1.34 (95% CI, 0.78-2.32), and 2.92 (95% CI, 1.61-5.28), respectively.
Conclusions—
Heavy alcohol consumption was associated with the higher risk of atrial fibrillation, whereas there was no association of less than moderate alcohol consumption and atrial fibrillation.
Coronary deaths during Midsummer festival in Finland: miseries of long, light nights