Creatine supplementation during pulmonary rehabilitation in chronic obstructive pulmonary disease

Background: Skeletal muscle wasting and dysfunction are strong independent predictors of mortality in patients with chronic obstructive pulmonary disease ( COPD). Creatine nutritional supplementation produces increased muscle mass and exercise performance in health. A controlled study was performed to look for similar effects in 38 patients with COPD. Methods: Thirty eight patients with COPD ( mean (SD) forced expiratory volume in 1 second (FEV1) 46 (15)% predicted) were randomised to receive placebo ( glucose polymer 40.7 g) or creatine ( creatine monohydrate 5.7 g, glucose 35 g) supplements in a double blind trial. After 2 weeks loading ( one dose three times daily), patients participated in an outpatient pulmonary rehabilitation programme combined with maintenance ( once daily) supplementation. Pulmonary function, body composition, and exercise performance ( peripheral muscle strength and endurance, shuttle walking, cycle ergometry) took place at baseline ( n = 38), post loading ( n = 36), and post rehabilitation ( n = 25). Results: No difference was found in whole body exercise performance between the groups: for example, incremental shuttle walk distance mean -23.1 m ( 95% CI -71.7 to 25.5) post loading and -21.5 m ( 95% CI -90.6 to 47.7) post rehabilitation. Creatine increased fat-free mass by 1.09 kg ( 95% CI 0.43 to 1.74) post loading and 1.62 kg ( 95% CI 0.47 to 2.77) post rehabilitation. Peripheral muscle performance improved: knee extensor strength 4.2 N. m ( 95% CI 1.4 to 7.1) and endurance 411.1 J ( 95% CI 129.9 to 692.4) post loading, knee extensor strength 7.3 N. m ( 95% CI 0.69 to 13.92) and endurance 854.3 J ( 95% CI 131.3 to 1577.4) post rehabilitation. Creatine improved health status between baseline and post rehabilitation (St George's Respiratory Questionnaire total score -7.7 ( 95% CI -14.9 to -0.5)). Conclusions: Creatine supplementation led to increases in fat-free mass, peripheral muscle strength and endurance, health status, but not exercise capacity. Creatine may constitute a new ergogenic treatment in COPD.