Creatine supplements in patients with idiopathic inflammatory myopathies who are clinically weak after conventional pharmacologic treatment: Six‐month, double‐blind, randomized, placebo‐controlled trial

• Published in: Arthritis and rheumatism 2007-05, Vol.57 (4), p.694-702
• Main Authors: Chung, Yuen‐li, Alexanderson, Helene, Pipitone, Nicoló, Morrison, Catherine, Dastmalchi, Maryam, Ståhl‐Hallengren, Christina, Richards, Selwyn, Thomas, E. Louise, Hamilton, Gavin, Bell, Jimmy D., Lundberg, Ingrid E., Scott, David L.
• Format: Article
• Language: English
• Subjects: 31P magnetic resonance spectroscopy; Administration, Oral; Biological and medical sciences; Clinical Medicine; Creatine - administration & dosage; Creatine - adverse effects; Creatine supplementation; Dermatomyositis; Diseases of striated muscles. Neuromuscular diseases; Diseases of the digestive system; Double-Blind Method; Energy Metabolism - drug effects; Exercise; Female; Humans; Klinisk medicin; Magnetic Resonance Spectroscopy; Male; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Middle Aged; Muscle function; Muscle Strength - drug effects; Muscle Weakness - drug therapy; Muscle Weakness - etiology; Muscle Weakness - metabolism; Myositis - complications; Myositis - drug therapy; Myositis - metabolism; Neurology; P-31 magnetic resonance spectroscopy; Phosphocreatine - metabolism; Phosphorus Isotopes; Placebos; Polymyositis; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Reumatologi och inflammation; Rheumatology and Autoimmunity; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Treatment Outcome
• ISSN: 0004-3591; 0893-7524; 1529-0131; 1529-0131; 1529-0123
• DOI: 10.1002/art.22687

Objective To test the hypothesis that oral creatine supplements with exercise are more effective than exercise alone in improving muscle function in patients with established dermatomyositis or polymyositis receiving chronic medical therapies who are clinically weak yet stable. Methods In a 6‐month, 2‐center, double‐blind, randomized controlled trial, patients were randomized to receive oral creatine supplements (8 days, 20 gm/day then 3 gm/day) or placebo. All patients followed a home exercise program. The primary outcome was aggregate functional performance time (AFPT), reflecting the ability to undertake high‐intensity exercise. Secondary outcomes included a functional index measuring endurance and muscle bioenergetics on 31P magnetic resonance spectroscopy (31P MRS). Patients were receiving stable immunosuppressive treatment and/or corticosteroids. Results A total of 37 patients with polymyositis or dermatomyositis were randomized (19 to creatine, 18 to placebo); 29 completed 6 months. Intent‐to‐treat analyses demonstrated that AFPT improved significantly at 6 months with creatine (median decrease 13%, range –32–8%) compared with placebo (median decrease 3%, range –13–16%; P = 0.029 by Mann‐Whitney U test). A completer analysis also showed significant benefits from creatine (P = 0.014). The functional index improved significantly with both creatine and placebo (P < 0.05 by paired Wilcoxon's rank sum test), with a significant benefit between groups in the completer analysis only. Phosphocreatine/β‐nucleoside triphosphate ratios using MRS increased significantly in the creatine group (P < 0.05) but not in the control group. No clinically relevant adverse events were associated with creatine. Conclusion Oral creatine supplements combined with home exercises improve functional performance without significant adverse effects in patients with polymyositis or dermatomyositis. They appear safe, effective, and inexpensive.