Obesity's Link With Atrial Fibrillation

Heart rate monitor, patient and doctors in background in intensive care unit
Heart rate monitor in intensive care unit. Caiaimage/Sam Edwards/Getty Images

Obesity is now recognized as a risk factor for a number of cardiovascular diseases, including coronary artery disease, heart failure, and stroke. Four new studies have confirmed the strong association between obesity and the irregular heart rhythm known as atrial fibrillation.

What Is Atrial Fibrillation?

Atrial fibrillation, also known as AF or “A-fib,” is an abnormal heart rhythm that is the most common type of arrhythmia (a medical term used for any problem with the rhythm or rate of the heart beat).

Atrial fibrillation increases the risk of stroke.

What Increases Risk for Developing Atrial Fibrillation?

There are a number of risk factors that have been identified that increase the risk of developing atrial fibrillation. These include age, pre-existing heart disease (such as coronary disease or cardiomyopathy), high blood pressure, congenital heart defects, hyperthyroidism, diabetes, lung disease, drinking large amounts of alcohol, and obesity. In some individuals, caffeine or psychological stress can trigger A-fib.

Obesity as a Risk Factor for Atrial Fibrillation

A good deal of research has established that obesity is a risk factor for atrial fibrillation, and that the risk seems to increase with increasing body mass index (BMI).

One investigation that examined findings from the Women’s Health Study, which includes over 34,000 women, found that obesity was a risk factor for persistent atrial fibrillation (atrial fibrillation that does not go away, but rather becomes a lifelong, chronic problem).

Another study, based on findings from the Atherosclerosis Risk in Communities Study (ARIC), found that obesity and weight gain are risk factors for the development of atrial fibrillation in men as well as in women.

In addition to prior research on the topic, four meta-analyses (studies that pool and analyze data from a great many other studies on the same topic) have now confirmed that obesity plays a major role in both the occurrence and the severity of atrial fibrillation.

These meta-analyses included a combined total of 51 controlled trials, and found that, for every 5-point rise in the BMI, the occurrence (incidence) of atrial fibrillation went up by 10% to 29%.

Weight Loss and Physical Activity Can Help

Other studies have found that weight loss can reduce the burden of atrial fibrillation, and that this improvement lasts for as long as the weight loss is maintained.

In the Women’s Health Initiative (WHI) Observational Study, which included over 93,000 postmenopausal women who were followed for an average of 11.5 years, investigators found that higher levels of physical activity reduced the risk of atrial fibrillation that otherwise would have been present due to obesity. This was found to be true for men in the ARIC study as well.

If you are obese or overweight, talk to your doctor about your risk for atrial fibrillation and what steps you can take to mitigate that risk.

Sources

Zoler ML. Meta-analyses strengthen obesity-atrial fib link. Cardiology News. June 2015.

National Heart, Lung, and Blood Institute. Explore atrial fibrillation. http://www.nhlbi.nih.gov/health/health-topics/topics/af/

Magnani JW, Hylek EM, Apovian CM. Obesity begets atrial fibrillation: a contemporary summary. Circulation 2013;128:401-405.

Sandhu RK, Conen D, Tedrow UB, et al. Predisposing factors associated with development of persistent compared with paroxysmal atrial fibrillation. J Am Heart Assoc 2014;3(3).

Pathak RK, Middeldorp ME, Meredith M, et al. Long-term effect of goal-directed weight management in an atrial fibrillation cohort: a long-term follow-up study (LEGACY). J Am Coll Cardiol 2015;65:2159-69.

Pathak RK, Mahajan R, Lau DH, Sanders P. The implications of obesity for cardiac arrhythmia mechanisms and management. Can J Cardiol 2015;31:203-10.

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