Randomized controlled trial of dietary creatine as an adjunct therapy to physical training in chronic obstructive pulmonary disease.
BACKGROUND
Skeletal muscle strength and bulk are reduced in patients with chronic obstructive pulmonary disease (COPD) and influence quality of life, survival, and utilization of health care resources. Exercise training during pulmonary rehabilitation (PR) can reverse some of these effects. In athletes and healthy elderly individuals, dietary creatine supplementation (CrS) has been shown to augment high-intensity exercise training, thereby increasing muscle mass.


OBJECTIVE
This article examines the effect of CrS on functional exercise capacity and muscle performance in people with COPD.


METHODS
One hundred subjects with COPD (mean [SD] age, 68.2 [8.2] yr; FEV(1), 44.0 [19.6] %predicted) were randomized to a double-blind, placebo-controlled, parallel group trial of CrS during 7 weeks of PR encompassing aerobic and resistance exercises. Subjects ingested creatine (22 g/d loading for 5 d; maintenance, 3.76 g/d throughout PR) or placebo. Baseline, postloading, and postrehabilitation measurements included pulmonary function, body composition, peripheral muscle strength, and functional performance (shuttle walking tests). A volunteer subgroup (n = 44) had pre- and postloading quadriceps muscle biopsies.


RESULTS
Eighty subjects completed the trial (38 creatine, 42 placebo). All outcome measures significantly improved after PR. There were no significant differences between groups post-PR (mean [SD] change in incremental shuttle walk distance, 84 [79] m in the creatine group vs. 83.8 [60] m in the placebo group; P = 1.0; knee extensor work, 19.2 [16] Nm [Newton meters] in the creatine group vs. 19.5 [17] Nm in the placebo group; P = 0.9). Muscle biopsies showed evidence of creatine uptake.


CONCLUSIONS
This adequately powered, randomized, placebo-controlled trial shows that CrS does not augment the substantial training effect of multidisciplinary PR for patients with COPD. Clinical trial registered with https://portal.nihr.ac.uk/Pages/NRRArchiveSearch.aspx (NO123138126).
Deacon
Sarah J
SJ
Institute for Lung Health, Department of Respiratory Medicine, Allergy and Thoracic Surgery, University Hospitals of Leicester NHS Trust, Glenfield Hospital, Leicester LE39QP, UK. sarah.deacon@uhl-tr.nhs.uk
Vincent
Emma E
EE
Greenhaff
Paul L
PL
Fox
John
J
Steiner
Michael C
MC
Singh
Sally J
SJ
Morgan
Michael D
MD
D000368:Aged; D003401:Creatine; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation*; D016896:Treatment Outcome; D014797:Vital Capacity
D003401:Creatine