A rare autoimmune disease, dermatomyositis generates inflammatory damage to muscles and skin. Its juvenile form begins at the median age of 7 years. Many patients experience persistent muscle fatigue and weakness, even when treatment (corticosteroids, immunosuppressants) results in true remission. These manifestations could be due in part to energy disorders, with in particular a possible reduction in the ability to use and / or produce ATP or phosphocreatine, which is involved in the production of energy during intense and short duration physical activities.
Clinical ineffectiveness
A team from the Hospital for Sick Children in Toronto (Canada) conducted a double-blind placebo-controlled trial to assess the feasibility of supplementation with creatine at a dose of 150 mg / kg / day or 4 , 69g / m2 / day, for six months, in 13 patients aged 7 to 18 years with juvenile dermatomyositis. Released in August 2020, the results of this trial show:
- compliance greater than or equal to 80% for 76.9% of participants;
- good tolerance of creatine;
- a statistically significant improvement in muscle metabolism with a reduction in the phosphate / phosphocreatine ratio and less variation in muscle pH during exercise;
- the absence of a significant difference between creatine and placebo for muscle function and strength, aerobic capacity, level of physical activity and activity of dermatomyositis.
To explain these mixed results, the authors cite in particular the small size of the trial, the choice of evaluation criteria and the lack of a concomitant physical activity program. The same team also initiated a new clinical trial in March 2020 to assess the effect of the combination of creatine, coenzyme Q and exercise in 15 participants with juvenile dermatomyositis.
