Peripheral muscle wasting in chronic obstructive pulmonary disease. Clinical relevance and mechanisms.

Abstract

Peripheral muscle wasting is a common finding in advanced chronic obstructive pulmonary disease (COPD) and several other chronic diseases. Although muscle wasting has long been recognized by clinicians (1), its relevance to patients' outcome and management has been overlooked. There is a renewed interest in this problem in respiratory and other chronic diseases as recent advances in clinical research have confirmed the negative impact of muscle wasting on patient survival (2, 3). At the same time, exciting and innovative research in molecular biology is improving our understanding of how muscle mass is maintained (4, 5). Effective treatment for muscle wasting has yet to be developed, but there is now evidence, from animal and human studies, that muscle mass may he manipulated with success in wasting disorders (4). As a result of this research, new molecules specifically targeted at maintaining or increasing muscle mass in patients with COPD or other chronic conditions should become available in the future. In this pulmonary perspective, the clinical significance of muscle wasting associated with COPD will he briefly reviewed, taking into account the knowledge obtained from the study of other chronic diseases. Based upon new developments in molecular biology, possible mechanisms leading to muscle wasting and potential therapeutic strategies will be presented as well as suggestions for future research. It is not the scope of the present study to provide a complete review of the literature on peripheral muscle function in COPD, which can be found elsewhere (6, 7).