Drinking too much alcohol may lead to abnormal rhythm of the atria, the upper chambers of the heart, according to a report from Denmark.

Drs. Lars Frost and Peter Vestergaard, at Aarhus University Hospital, examined the relationship between alcohol consumption and risk of atrial fibrillation or flutter among participants of the Danish Diet, Cancer, and Health Study.

As reported in the Archives of Internal Medicine, approximately 23,000 men and 25,000 women completed questionnaires regarding alcohol consumption between 1993 and 1997. Through the end of 2001, atrial fibrillation or flutter occurred in 374 men (1.7 percent) and 182 women (0.7 percent).

After taking into account age, height, weight, smoking, hypertension, cholesterol and level of education, the risk for the atrial irregularities was 46 percent higher among men who drank the most alcohol compared with those who drank the least.

For women, on the other hand, the corresponding increase in risk was only 14 percent, which wasn’t significant from a statistical standpoint.

The difference between men and women in this study is probably because more men than women were alcohol drinkers, and “we did not have much statistical power in women,”

Frost told Reuters Health.

It seems prudent to keep alcohol consumption to no more than two drinks a day to reduce risk of atrial fibrillation, he added.

SOURCE: Archives of Internal Medicine, October 11, 2004.