Regardless of their fat level, heart disease patients might do well to muscle up a bit.

In a new study assessing the link between body composition and risk of earlier death among heart disease patients, UCLA researchers found that higher levels of muscle mass seem to provide a protective effect, even in people with high fat levels. The new findings could help explain the “obesity paradox,” in which heart disease patients with higher body mass index, or BMI, live longer than those with a lower BMI.

The research, published online April 1 in the American Journal of Cardiology, emphasizes the importance of considering a patient’s overall body composition, not simple BMI. Here’s what the study’s primary investigator, Dr. Preethi Srikanthan, associate clinical professor of medicine in the division of endocrinology at the David Geffen School of Medicine at UCLA, had to say about the study.

What does this finding mean for patients?

“Our study emphasizes the importance of maintaining muscle mass, rather than focusing on weight loss, in order to prolong life--even in individuals with higher cardiovascular risk. In addition to using simple devices to measure and monitor changes in body composition in the clinic, clinicians should encourage their patients to participate in resistance exercises as a part of healthy lifestyle changes rather than focusing primarily on, and monitoring, weight loss.”

Why does muscle mass matter so much?

“The protective effect is, in large part, related to metabolism. More muscle is associated with lower insulin resistance, which in turn contributes to the development of pre-diabetes and diabetes.”

(Muscle takes up sugar without the need for insulin and is thus a “sink” for glucose disposal after a person eats. This means that functioning muscle lowers blood sugar, without insulin.)

“In a person with insulin resistance, this means less insulin needs to be produced by the body because the rise in blood sugar after meals is attenuated by the uptake into the muscles.”

*The researchers examined National Health and Nutrition Examination Survey from 6,451 participants who had prevalent cardiovascular disease, assessing their body composition, as defined by dual x-ray absorptionmetry, with the risk of death from any cause.

Tags: BMI, body mass index, diabetes, Dr. Preethi Srikanthan, endocrinology, fat level, heart disease, News & Insights, pre-diabetes, weight loss