A meta-analysis on a therapeutic dilemma: to exercise or not to exercise in cachexia

Physical exercise has important effects on secondary prevention or intervention against several diseases. Although there are good reasons to recommend regular physical activity in patient populations, recommending exercise is not a straightforward endeavor in patients with chronic diseases. Cachexia, a severe skeletal muscle wasting syndrome, is often associated with numerous chronic diseases, such as cancer, acquired immune deficiency syndrome, rheumatoid arthritis, chronic obstructive pulmonary disease, renal failure and chronic heart failure. Thus the question arises whether to exercise or not to exercise in cachexia. We performed a meta-analysis on scientific papers from the last decade dealing with exercise conducted by cachectic patients. We observed differential effects exerted by exercise, depending on the pathology considered and the kind of exercise performed: a global positive effect of exercise was observed when all the pathologies considered were pooled together; also, a significantly positive effect of exercise was observed in patients affected by rheumatoid arthritis. On the contrary, when rheumatoid arthritis was excluded from the analysis the effects of exercise on cachexia were not significant. Considering separately the kind of exercises performed, it is interesting to observe how resistance exercise had positive, statistically significant effects on cachexia as opposed to endurance exercise. This is the first study that addresses the effects of exercise training in cachexia independently of a specific chronic disease.