Big men more susceptible to abnormal heart rhythm

NEW YORK, 17 april 2009-- Older men who were big during their 20s face an increased risk of suffering from an abnormal heart rhythm called atrial fibrillation.

During an episode of atrial fibrillation, or AF, abnormal electrical activity in the heart causes its upper two chambers to beat in a rapid, uncoordinated rhythm; the arrhythmia itself is not life-threatening, but over time AF can contribute to stroke or heart failure in some people.

In a study of nearly 7000 men, large body size at age 20 and subsequent weight gain emerged as important predictors of the development of AF later in life. Men who fell in the top category in terms of body size at age 20 were twice as likely to develop AF as those that fell in the lowest body size category.

"Atrial fibrillation proved to be significantly more common both among those men who were big during their youth, as well as among those who gained a considerable amount of weight later on in life," Dr. Annika Rosengren, from Sahlgrenska Academy, Goteberg, Sweden, noted in a statement.

Prior research has established obesity as a risk factor for AF, but whether other body size factors also influenced the risk was unclear.

The new study found that the risk of AF increases linearly with both body size and weight gain. The larger the men were in their 20s and the more weight they gained during their life, the greater their risk of developing AF.

The fact that the men were big in their youth does not mean that they were obese; these big men were just tall and well-built, the investigators note.

"Since both weight and height are increasing among young people, it's quite likely that atrial fibrillation will become more common when today's young men reach their 60s and 70s," predicted Rosengren, particularly if the tendency to put on weight later on in life continues.

SOURCE: European Heart Journal, online March 20, 2009.