Muscle function in COPD: a complex interplay

Abstract

Anna V Donaldson,1,* Matthew Maddocks,2,* Dario Martolini,1,* Michael I Polkey,1 William D-C Man,1,3 1NIHR Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London; 2King's College London, Cicely Saunders Institute; London; 3Harefield Pulmonary Rehabilitation Unit, Harefield, United Kingdom*These authors contributed equally to this reviewAbstract: The skeletal muscles play an essential role in life, providing the mechanical basis for respiration and movement. Skeletal muscle dysfunction is prevalent in all stages of chronic obstructive pulmonary disease (COPD), and significantly influences symptoms, functional capacity, health related quality of life, health resource usage and even mortality. Furthermore, in contrast to the lungs, the skeletal muscles are potentially remedial with existing therapy, namely exercise-training. This review summarizes clinical and laboratory observations of the respiratory and peripheral skeletal muscles (in particular the diaphragm and quadriceps), and current understanding of the underlying etiological processes. As further progress is made in the elucidation of the molecular mechanisms of skeletal muscle dysfunction, new pharmacological therapies are likely to emerge to treat this important extra-pulmonary manifestation of COPD.Keywords: skeletal muscle, pulmonary rehabilitation, exercise, quadriceps, diaphragm