S. Dover, MSc, Child Health Evaluative Sciences, The Hospital for Sick Children.
S. Stephens, PhD, Neurosciences and Mental Health, The Hospital for Sick Children.
J Rheumatol. 2021 Mar;48(3):434-441. doi: 10.3899/jrheum.191375. Epub 2020 Aug 1.
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.
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 -tests.
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.
Creatine supplementation in children with JDM is feasible to study, and is safe and well-tolerated; it may lead to improvements in muscle metabolism.
评估研究肌少症（JDM）患者肌酸的可行性。次要目标是确定肌酸对肌肉功能和代谢、有氧能力、疲劳、身体活动和生活质量（QOL）的影响，以及其安全性。
我们进行了一项为期 6 个月的双盲、随机、多基线设计；患者被分配到肌酸或安慰剂组。通过参加研究访问、完成研究程序和依从性来评估可行性。使用标准化运动测试评估肌肉功能、有氧能力和肌肉力量。使用 31 磷磁共振波谱（31P-MRS）方案评估肌肉代谢。通过问卷评估疲劳、身体活动和 QOL。使用随机化（置换）检验估计统计显着性。使用配对 t 检验计算基线和研究结束时的结果测量值的变化。
研究药物的中位数（范围）依从率为 88.5%（20.5-95.5%），80%或更高依从率的受试者比例为 76.9%。没有错过研究访问。与安慰剂相比，接受肌酸的受试者在肌肉功能、力量、有氧能力、疾病活动、疲劳、身体活动或 QOL 方面没有统计学显着变化。与基线相比，在研究结束时，肌肉代谢发生了统计学显着的适应性变化（例如，运动后肌肉 pH 的变化减少，以及磷酸盐/磷酸肌酸比减少）。没有发生明显的不良反应。
肌少症患儿补充肌酸是可行的研究方法，且安全且耐受性良好；它可能会导致肌肉代谢的改善。
