Obesity contributes to increased risk of AF across clinical settings

A meta-analysis of 51 studies found that increases in body mass index (BMI) were associated with a significant risk of atrial fibrillation. The results were consistent across different clinical settings.

Christopher X. Wong, MBBS, MSc, of University of Adelaide and the Royal Adelaide Hospital in Australia, and colleagues published their findings online in the Journal of the American College of Cardiology: Clinical Electrophysiology on May 27.

They cited previous research that found obesity accounted for an estimated one-fifth of the cases of atrial fibrillation, which is the most common, sustained arrhythmia diagnosed in clinical practice. There are now 33 million cases of atrial fibrillation in the world, according to the researchers. They added that the disease costs an additional $26 billion each year in the U.S. and is likely to increase in recent years as the population ages.

This analysis included a comprehensive search of the Medline and EMBASE databases through January 2012 and a manual search of reference lists of individual studies and review articles. Wong et al searched for terms such as obesity, overweight, BMI, arrhythmia and atrial fibrillation and included observational, cross-sectional, case-control or cohort studies that examined BMI and atrial fibrillation.

Of the 51 studies included in the analysis, 23 reported on incident atrial fibrillation, 12 reported on post-operative atrial fibrillation and 16 reported on post-ablation atrial fibrillation. There were 157,518 individuals and 6,088 cases of atrial fibrillation in the incident studies, 62,160 individuals and 16,768 cases of atrial fibrillation in the post-operative studies and 5,864 individuals in the post-ablation studies.

Wong et al found that for every five-unit increase in BMI, there was an additional 10 percent to 29 percent increased risk of atrial fibrillation.