Greater endurance capacity and improved dyspnoea with acute oxygen supplementation in idiopathic pulmonary fibrosis patients without resting hypoxaemia

• Published in: Respirology (Carlton, Vic.) Vic.), 2017-07, Vol.22 (5), p.957-964
• Main Authors: Dowman, Leona M., McDonald, Christine F., Bozinovski, Steven, Vlahos, Ross, Gillies, Rebecca, Pouniotis, Dodie, Hill, Catherine J., Goh, Nicole S.L., Holland, Anne E
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Blood pressure; Creatine; Creatine kinase; Cross-Over Studies; Cytokines; Dyspnea; Dyspnea - physiopathology; exercise; Exercise - physiology; Exercise Tolerance - physiology; Fatigue; Female; Fibrosis; Heart rate; Humans; Hypoxia; idiopathic pulmonary fibrosis; Idiopathic Pulmonary Fibrosis - complications; Idiopathic Pulmonary Fibrosis - physiopathology; Idiopathic Pulmonary Fibrosis - therapy; Interleukin 10; Interleukin 6; Interleukin-10 - metabolism; Lactic acid; Lung diseases; Male; Metabolism; Middle Aged; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiopathology; Musculoskeletal system; Oxidative metabolism; Oxidative stress; Oxidative Stress - physiology; Oxygen; Oxygen Inhalation Therapy; Physical training; Physiology; Pulmonary fibrosis; Respiration; Respiratory diseases; Rest; Single-Blind Method; Skeletal muscle; Supplements; Thiobarbituric acid
• ISSN: 1323-7799; 1440-1843
• DOI: 10.1111/resp.13002

ABSTRACT Background and objective Supplemental oxygen is commonly prescribed in patients with idiopathic pulmonary fibrosis (IPF), although its benefits have not been proven. The aims of this study were to investigate the effect of oxygen on oxidative stress, cytokine production, skeletal muscle metabolism and physiological response to exercise in IPF. Methods Eleven participants with IPF received either oxygen, at an FiO2 of 0.50, or compressed air for 1 h at rest and during a cycle endurance test at 85% of peak work rate. Blood samples collected at rest and during exercise were analysed for markers of oxidative stress, skeletal muscle metabolism and cytokines. The protocol was repeated a week later with the alternate intervention. Results Compared with air, oxygen did not adversely affect biomarker concentrations at rest and significantly improved endurance time (mean difference = 99 ± 81s, P = 0.002), dyspnoea (−1 ± 1 U, P = 0.02), systolic blood pressure (BP; −11 ± 11 mm Hg, P = 0.006), nadir oxyhaemoglobin saturation (SpO2 ; 8 ± 6%, P = 0.001), SpO2 at 2‐min (7 ± 6%, P = 0.003) and 5‐min isotimes (5 ± 3, P