Exercise May Help Patients with Heart FailureOctober 30, 2001
NEW YORK (Reuters Health) - Moderate aerobic exercise appears to lower levels of an immune system protein that may contribute to congestive heart failure (CHF), new study findings suggest.
In the study, a group of men with CHF participated in an exercise program at a rehabilitation center supervised by instructors specializing in cardiac rehabilitation. After the 3-month program, the men had significantly lower levels of tumor necrosis factor (TNF)-alpha, a protein that helps trigger inflammation.
Lower levels of the protein were also associated with improved endurance and increased survival over 4 years, report researchers led by Dr. Alf Inge Larsen of Central Hospital in Rogaland, Norway. They published their findings in the October issue of the American Journal of Cardiology.
"Exercise training may be beneficial in patients with CHF on optimal medical therapy," they explain, "at least partly by down-regulating TNF-alpha levels." However, any patient with a heart condition should consult their doctor first before embarking on an exercise program.
CHF occurs when the heart can no longer meet the body's demand for blood and oxygen, typically due to an underlying cardiovascular condition like coronary artery disease. CHF is marked by quick fatigue and shortness of breath during non-strenuous activity and rest. It is a leading cause of hospitalization for Americans older than 65.
In the study, the researchers looked at levels of immune system proteins in the blood of 28 men with congestive heart failure, whose average age was 67, and compared them with levels in the blood of 16 healthy older men.
Patients exercised at least 3 days a week with an instructor for several weeks, after which they were encouraged to exercise at home. Each supervised session included a 10-minute warm-up, 25 minutes of low-impact endurance training--including walking--and 10 minutes of cooling down and stretching.
After 12 weeks, patients had improved their aerobic capacity, and all but 8 patients (about 71% overall) had significantly lower levels of TNF-alpha. There was no difference in levels of other immune system proteins such as interleukin-6 or interleukin-8 following exercise training, however.
It is not yet clear how exercise lowers levels of TNF-alpha, but the authors speculate that increased aerobic capacity may help maintain adequate oxygen levels during exercise. The failure to get enough oxygen during exercise or at high altitudes, for instance, can stimulate inflammatory immune system proteins.
"In the present study a decrease in TNF-alpha during exercise training was associated with improved long-term survival, suggesting that the decrease in TNF-alpha levels may be of clinical relevance," the authors conclude.
SOURCE: The American Journal of Cardiology 2001;88:805-808.