title: The muscle oxidative regulatory response to acute exercise is not impaired in less advanced COPD despite a decreased oxidative phenotype.
abstract: Already in an early disease stage, patients with chronic obstructive pulmonary disease (COPD) are confronted with impaired skeletal muscle function and physical performance due to a loss of oxidative type I muscle fibers and oxidative capacity (i.e. oxidative phenotype; Oxphen). Physical activity is a well-known stimulus of muscle Oxphen and crucial for its maintenance. We hypothesized that a blunted response of Oxphen genes to an acute bout of exercise could contribute to decreased Oxphen in COPD. For this, 28 patients with less advanced COPD (age 65 ± 7 yrs, FEV1 59 ± 16% predicted) and 15 age- and gender-matched healthy controls performed an incremental cycle ergometry test. The Oxphen response to exercise was determined by the measurement of gene expression levels of Oxphen markers in pre and 4h-post exercise quadriceps biopsies. Because exercise-induced hypoxia and oxidative stress may interfere with Oxphen response, oxygen saturation and oxidative stress markers were assessed as well. Regardless of oxygen desaturation and absolute exercise intensities, the Oxphen regulatory response to exercise was comparable between COPD patients and controls with no evidence of increased oxidative stress. In conclusion, the muscle Oxphen regulatory response to acute exercise is not blunted in less advanced COPD, regardless of exercise-induced hypoxia. Hence, this study provides further rationale for incorporation of exercise training as integrated part of disease management to prevent or slow down loss of muscle Oxphen and related functional impairment in COPD.
authors.affiliation: Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Ilse G M
authors.initials: IG
authors.lastname: Slot
authors.affiliation: Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Bram
authors.initials: B
authors.lastname: van den Borst
authors.affiliation: Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Valéry A C V
authors.initials: VA
authors.lastname: Hellwig
authors.affiliation: Pulmonology Department-Muscle and Respiratory System Research Unit (URMAR), Research Institute of Hospital del Mar (IMIM), Department of Experimental and Health Sciences (CEXS), Pompeu Fabra University (UPF), Barcelona Biomedical Research Park (PRBB), Barcelona, Spain ; Network of Excellence in Respiratory Research (CIBERES), Institute of Health Carlos III (ISCIII), Bunyola, Majorca, Balearic Islands, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Barreiro
authors.affiliation: Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Annemie M W J
authors.initials: AM
authors.lastname: Schols
authors.affiliation: Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Harry R
authors.initials: HR
authors.lastname: Gosker
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D015444:Exercise; D005080:Exercise Test; D005260:Female; D015870:Gene Expression; D006801:Humans; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009243:NAD / Q000378:metabolism; D018384:Oxidative Stress; D010101:Oxygen Consumption; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D047492:Peroxisome Proliferator-Activated Receptors / Q000235:genetics / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000473:pathology; D052097:Quadriceps Muscle / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012720:Severity of Illness Index; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D002352:Carrier Proteins; C486497:PPARGC1A protein, human; C455622:PPARGC1B protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D047492:Peroxisome Proliferator-Activated Receptors; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D009243:NAD