Diabetics at increased risk of developing atrial fibrillation

Patients receiving treatment for diabetes had a 40% higher risk of developing atrial fibrillation than those without the chronic disease, after adjusting for body mass index and other variables, according to a study in the Journal of General Internal Medicine.

Risk of arrhythmia, which the American Heart Assn. says affects about 2.2 million Americans, rose 3% for each additional year that patients were treated for diabetes. The risk also increased among patients with poor glycemic control, according to the study, posted online April 20.

Lead study author Sascha Dublin, MD, PhD, said there is not yet enough data to recommend atrial fibrillation screening for all diabetics. But she suggests that physicians be aware of the link between the two conditions and consider testing for atrial fibrillation when diabetic patients have relevant symptoms.

"Atrial fibrillation is common. It's getting more common. And it can be very dangerous," said Dr. Dublin, assistant scientific investigator at Group Health Research Institute in Seattle. "We need to look for more than just a [diabetic patient's] blood sugar control if we want to decrease the risk of atrial fibrillation" among this population.

For the study, researchers analyzed data on 1,410 Group Health Cooperative patients, age 30 to 84, who had newly recognized atrial fibrillation that occurred between October 2001 and December 2004 (link). Researchers compared the patients with arrhythmia to 2,203 Group Health members who did not have it. Group Health is a Seattle-based physician, hospital and health plan system.

Among those with atrial fibrillation, 17.9% were being treated by a physician with medicine for diabetes. In the control group, 14.1% were being treated for the disease.

Researchers found that patients with poorly controlled diabetes -- hemoglobin A1c levels greater than 9% -- had two times the risk of atrial fibrillation than did people without diabetes. For diabetics with hemoglobin A1c levels of 7% or less, the risk for developing arrhythmia was about equal to that of patients without diabetes.

Diabetics receiving treatment for six to 10 years had a 51% greater risk of developing atrial fibrillation than did those without diabetes. The elevation in risk increased to 64% among diabetics treated for more than 10 years.

"Duration of [diabetes treatment] seems to have an independent affect. It effects people with good and bad control. Overall, having pretty good control doesn't seem to protect you from the possible [elevated risk due to] duration," Dr. Dublin said.