People with heart failure tend to feel tired all the time. That's because their bodies are producing harmful chemical signals. One result of these signals is the breakdown of muscles throughout the body. This muscle wasting -- doctors call it cachexia -- can be very severe.
Doctors already tell heart failure patients to exercise. It's mainly for rehabilitation. Exercise helps their hearts pump more blood and helps their lungs take in more air. Now there's an even better reason to exercise, says researcher Stephan Gielen, MD, of the University of Leipzig Heart Center in Germany.
"For patients with stable chronic heart failure, regular aerobic exercise training should not be regarded as rehabilitation only, but as a continuing treatment with the potential to [change] the underlying disease process," says Gielen in a news release. His study appears in the Sept. 3 issue of the Journal of the American College of Cardiology.
Bustle for Muscle -- And More
Gielen's research team enlisted the help of 20 men, aged 70 or younger, whose medication had stabilized their heart failure for at least three months.
Initially, none of the men was exercising. During the six-month study, half the men continued to sit around. The other 10 men exercised on a stationary bicycle for 10 minutes, four to six times a day. They also participated in a one-hour group training session -- walking, calisthenics, or non-competitive ball games -- once a week.
The men agreed to let the researchers take biopsies of their thigh muscles. These tissue samples told an amazing story. At first, the men's muscles were full of inflammatory cytokines -- chemical messengers that keep the body in a state of immune alarm and that lead to muscle breakdown. This didn't change in the sedentary men. But those who exercised saw a significant drop in these harmful chemical messengers.
What's going on? Douglas L. Mann, MD, of Houston's Baylor College of Medicine, has an idea. In an editorial accompanying Gielen's study, he and colleague Michael B. Reid, PhD, note that exercise causes the release of harmful chemicals not unlike those released in heart failure patients. But they don't hurt anything, because exercise also buffers the body from the chemicals' harmful effects.
That same buffer might be what protected the heart failure patients in Gielen's study.
"The biggest complaint I get from patients who are well treated for their heart failure is that they are just tired all the time," says Mann in a news release. "That's why these findings are potentially exciting. Here's a new biochemical pathway that has not been studied."
Eventually, the findings may lead to new treatments for heart failure. In the meantime, the idea that exercise fights muscle wasting needs to be proved in larger clinical trials. But doctor-supervised exercise can't hurt heart failure patients who are able to do it. And it just might be a huge help.