PT  - JOURNAL ARTICLE
AU  - Saunya Dover
AU  - Samantha Stephens
AU  - Jane E.  Schneiderman
AU  - Eleanor Pullenayegum
AU  - Greg D.  Wells
AU  - Deborah M.  Levy
AU  - Jo-Anne Marcuz
AU  - Kristi Whitney
AU  - Andreas Schulze
AU  - Ingrid Tein
AU  - Brian M.  Feldman
TI  - The Effect of Creatine Supplementation on Muscle Function in Childhood Myositis: A Randomized, Double-blind, Placebo-controlled Feasibility Study
AID  - 10.3899/jrheum.191375
DP  - 2020 Aug 01
TA  - The Journal of Rheumatology
PG  - jrheum.191375
4099  - http://www.jrheum.org/content/early/2021/01/12/jrheum.191375.short
4100  - http://www.jrheum.org/content/early/2021/01/12/jrheum.191375.full
AB  - Objective To evaluate the feasibility of studying creatine in juvenile dermatomyositis ( JDM). Secondary objectives were to determine the effect of creatine on muscle function and metabolism, aerobic capacity, fatigue, physical activity, and quality of life (QOL), as well as its safety. Methods We conducted a 6-month, double-blind, randomized, multiple-baseline design; patients were assigned to creatine or placebo. Feasibility was assessed using attended study visits, completed study procedures, and adherence. Muscle function, aerobic capacity, and muscle strength were assessed with standardized exercise tests. Muscle metabolism was assessed using a 31-Phosphorus Magnetic Resonance Spectroscopy protocol. Fatigue, physical activity, and QOL were assessed by questionnaires. Statistical significance was estimated using a randomization (permutation) test. Changes in outcome measures taken at baseline and end-of-study were calculated using paired t-tests. Results Median (range) adherence to the study drug was 88.5% (20.5–95.5%) and the proportion of subjects with 80% adherence or higher was 76.9%. There were no missed study visits. There were no statistically significant changes in muscle function, strength, aerobic capacity, disease activity, fatigue, physical activity, or QOL while subjects were receiving creatine compared to placebo. There were statistically significant adaptations in muscle metabolism (e.g., decrease in change in muscle pH following exercise, and decrease in phosphate/phosphocreatine ratio) at the end-of-study compared to baseline. There were no significant adverse effects. Conclusion Creatine supplementation in children with JDM is feasible to study, and is safe and well-tolerated; it may lead to improvements in muscle metabolism.