Influence of Chronic Hypoxia on Oxidative Phenotype in Patients With Chronic Obstructive Pulmonary Disease

In addition to chronic airflow obstruction, patients with Chronic Obstructive Pulmonary Disease (COPD) suffer from skeletal muscle dysfunction which is a prominent and disabling feature and also an independent determinant of survival. Muscular impairment involves loss of muscle oxidative phenotype (OXPHEN: a slow-to-fast shift in fibre types and reduced oxidative capacity). Since hypoxia obviously is a key feature of COPD, the aim of this study is to elucidate the role of hypoxia in loss of muscle OXPHEN. Thus, OXPHEN and expression levels of its key regulators will be determined in the baseline biopsies for association with the degree of hypoxemia. In addition, expression levels of the key OXPHEN regulators will be measured in pre/post exercise biopsies.