Dysfunctional skeletal musculature of the lower limbs is related to low quality of life, exercise intolerance and higher mortality in patients with COPD. Limb muscle dysfunction in COPD consists of muscle atrophy and reduced muscle strength but also intra-muscular alterations in oxidative capacity and mitochondrial function are often present. Moreover, reduced blood flow to exercising muscle may also contribute to the muscle dysfunction in COPD. The mechanisms responsible for muscle dysfunction in COPD patients remain unclear but could be a consequence of reduced lung function, inflammation, medications or low physical activity. Loss of lung function with COPD is normally irreversible so the transition to near-normal lung function after lung transplantation is a unique model to investigate the adaptation of the limb muscle to improved lung function. Thus, the purpose of this project is to investigate the effect of lung transplantation on limb muscle function (mitochondrial function, oxidative enzyme capacity, fiber type distribution, oxygen delivery/uptake) and daily physical activity level in patients with COPD. The project has a translational focus on muscle dysfunction in COPD and uses methodologies from clinical medicine, integrative physiology and molecular biochemistry in order to gain knowledge of mechanisms behind limb muscle dysfunction and exercise intolerance in COPD.
