LONG-TERM OXYGEN-THERAPY MAY IMPROVE SKELETAL-MUSCLE METABOLISM IN ADVANCED CHRONIC OBSTRUCTIVE PULMONARY-DISEASE PATIENTS WITH CHRONIC HYPOXEMIA

Skeletal muscle metabolite depletion exists in advanced chronic obstru ctive pulmonary disease (COPD) patients with chronic hypoxaemia. The p urpose of this study was to investigate if long-term oxygen therapy (L TOT) can improve skeletal muscle energy metabolism. Eight patients wit h advanced COPD, four with chronic hypoxaemia, were investigated using muscle biopsy specimens from the quadriceps femoris muscle applying t he needle biopsy technique. The investigation was performed twice, bef ore and after approximately 8 months of LTOT in the hypoxaemic patient s. Eight healthy controls of similar age were also investigated. In th e COPD patients, muscle glycogen, ATP and creatine phosphate (CrP) con centrations, were 42% (P<0.01), 18% (P<0.05) and 21% (P=n.s.) lower th an in the healthy controls, respectively, while creatine (Cr) and lact ate concentrations were 21% and 90% higher, respectively in the COPD p atients compared to the healthy control subjects (P<0.05). After LTOT, the 'energy index' CrP/(CrP+Cr) ratio increased by 0.12 in the LTOT p atients but decreased by 0.12 in the control COPD patients (P<0.05). T he results indicate an improvement in skeletal muscle energy metabolis m during LTOT in COPD patients with chronic hypoxaemia.