Diabetes was associated with higher risk of developing atrial fibrillation.
Now a population-based case-control study led by Dr. Susan Heckbert involving 1,410 people with newly-recognized atrial fibrillation and 2,203 controls without atrial fibrillation over a three year period has found the following:
- Patients with diabetes were 40 percent more likely to be diagnosed with atrial fibrillation than were people without diabetes.
- The risk of atrial fibrillation rose by 3 percent for each additional year that patients had diabetes.
- For patients with high blood sugar (glycosylated hemoglobin, also known as HBA1c more than 9 percent), the risk of atrial fibrillation was twice that for people without diabetes.
- But patients with well-controlled diabetes (HBA1c 7 percent or less) were about equally likely to have atrial fibrillation as people without diabetes.
Unlike most prior studies, this one also adjusted for patients' weight, which is important because both diabetes and atrial fibrillation are more common in heavier people.
About one in 100 Americans -- and nearly nine in 100 over age 80 -- have atrial fibrillation, according to Dr. Heckbert, a professor of epidemiology and scientific investigator in the Cardiovascular Health Research Unit at the University of Washington (UW).
In many cases, atrial fibrillation has no symptoms, and it is not necessarily life threatening.
But it can cause palpitations, fainting, fatigue, or congestive heart failure. Atrial fibrillation can also make blood pool -- and sometimes clot -- in the atria. When parts of clots break off and leave the atria, they can lead to embolic strokes, as happens in more than 70,000 Americans a year.
Dublin S, Glazer NL, Smith NL, Psaty BM, Lumley T, Wiggins KL, Page RL, Heckbert SR. Diabetes Mellitus, Glycemic Control, and Risk of Atrial Fibrillation. J Gen Intern Med. 2010 Apr 20. [Epub ahead of print]