Evidence for a link between alcohol consumption and atrial fibrillation is conflicting, though, according to an article in the October 11 issue of The Archives of Internal Medicine, one of the JAMA/Archives journals.

Lars Frost, M.D., Ph.D., and Peter Vestergaard, M.D., Ph.D., from Aarhus University Hospital, Aarhus, Denmark, performed a follow-up study among 47,949 participants (average age, 56 years; 22,528 men; 25,421 women) in the Danish Diet, Cancer, and Health Study to investigate associations between alcohol consumption and atrial fibrillation.

Patients were recruited for the Danish Diet, Cancer, and Health Study between December 1993 and May 1997. Participants were born in Denmark and had no history of cancer. Part of the study used questionnaires to assess alcohol consumption. Participants were asked what type of alcohol they drank (beer, wine or spirits) and how often.

The researchers found that the average consumption of alcohol per day was 28.2 grams for men and 13.9 grams for women. More than half of the women consumed less than one unit of alcohol per day, or less than 10 grams of alcohol. The percentage of men and women who were abstainers at the beginning of the study was 2.1 percent and 3.0 percent, respectively.

During the follow-up period (average of approximately 5.7 years), 556 participants developed atrial fibrillation (including 374 men [1.7 percent] and 182 women [0.7 percent]). There was a modest increase in risk of atrial fibrillation that corresponded with increasing alcohol consumption in men, but not among women.

Compared to men who drank the least amount of alcohol (first quintile), men in the second, third, fourth and fifth quintiles (increasing alcohol consumption), had a 4 percent increase in risk, 44 percent increase in risk, 25 percent increase in risk and 46 percent increase in risk for atrial fibrillation, respectively.

Compared to women in the lowest quintile of alcohol consumption, women in the second, third, fourth and fifth quintiles had a nine percent increase in risk, 27 percent increase in risk, 23 percent increase in risk and 14 percent increase in risk, respectively.

"Consumption of alcohol was associated with an increased risk of atrial fibrillation or flutter in men," the researchers write. "In women, moderate consumption of alcohol did not seem to be associated with risk of atrial fibrillation or flutter."