Alcohol consumption may slightly increase the risk for atrial fibrillation or atrial flutter in men but not in women, according to an article in the October 11th issue of The Archives of Internal Medicine.

According to background information in the article, conflicting evidence for a link between alcohol consumption and atrial fibrillation has been published. In the current study, Lars Frost, MD, PhD, and Danish colleagues 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.

Study patients had been 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 distilled 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 (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, 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 with 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 with women in the lowest quintile of alcohol consumption, women in the second, third, fourth and fifth quintiles had a 9 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 wrote. “In women, moderate consumption of alcohol did not seem to be associated with risk of atrial fibrillation or flutter.”