Not Body Fat but Large Muscle Mass Is Linked to Atrial Fibrillation: Study

Senior man push up in fitness gym. Mature healthy lifestyle.New research on atrial fibrillation offers a new perspective on those more at risk for the heart condition. The study from Aarhus University suggests that the risk of atrial fibrillation is not linked to the amount of body fat as previously thought. Instead, the relationship exists between large muscle mass and atrial fibrillation.

Senior Researcher at the Research Unit for General Practice, Morten Fenger-Grøn is responsible for the study together with Consultant Cardiologist and Clinical Associate Professor at the Department of Clinical Medicine, Lars Frost who found the association between atrial fibrillation and high fat-free weight.


“While it’s correct that overweight individuals have a clearly elevated risk of atrial fibrillation, there is no clear evidence that fat is of any significance when we adjust for these individuals’ high fat-free mass.
Conversely, it appears that people with high fat-free weight do have a high risk, regardless of whether they have a lot of fat on their body or not,” explains Morten Fenger-Grøn.

High Body Fat

In many people’s eyes, large muscle mass is likely seen as the opposite of high body fat, but it turns out that to some extent, the same people have a lot of both. And when these people have a high risk of atrial fibrillation, we tend to interpret it as proof that too much fat is harmful,” he added.

Researchers believe that many people may have undiagnosed atrial fibrillation because people who are muscular without much body fat appear to be very healthy.

Fenger-Grøn cautions, “It’s a reminder that the causal mechanisms behind atrial fibrillation are completely different than those behind many other heart diseases—and sometimes almost the opposite. It’s important to really understand this if we are to prevent that the occurrence of atrial fibrillation keeps increasing, while those for other heart conditions are declining.”


Many health concerns surround obesity and experts warn about being overweight. However, clarifying the health conditions that are directly related to weight are important for those who may not realize they are at risk. By suggesting a causal link to atrial fibrillation, which runs via inflammation caused by adipose tissue, doctors may be able to help reduce the risk in high fat-free weight patients.

Atrial fibrillation affects as many as one in three people in the United States. In the past, doctors have advised patients to lose weight as a way of preventing the condition. But this study shows that it is not the amount of fat, but rather the fat-free weight that has a direct link to atrial fibrillation.

This study helps to outline the importance of risk prevention treatments in those who may not typically be thought of as one who may suffer from cardiovascular disease. Patients who are muscular and have little body fat should be checked by their doctor regularly for atrial fibrillation.

Author Bio

About eight years ago, Mat Lecompte had an epiphany. He’d been ignoring his health and suddenly realized he needed to do something about it. Since then, through hard work, determination and plenty of education, he has transformed his life. He’s changed his body composition by learning the ins and outs of nutrition, exercise, and fitness and wants to share his knowledge with you. Starting as a journalist over 10 years ago, Mat has not only honed his belief system and approach with practical experience, but he has also worked closely with nutritionists, dieticians, athletes, and fitness professionals. He embraces natural healing methods and believes that diet, exercise and willpower are the foundation of a healthy, happy, and drug-free existence.