Appropriate physical activity is an integral part of the treatment of idiopathic myositis (or inflammatory myopathies), though the mechanisms of action being are not yet clearly defined.
A study of 7 patients with dermatomyositis and 6 patients with autoimmune necrotizing myopathy showed, after a 12-week physical training program (aerobic and resistance):
- an increase in the expression of genes related to autophagy and lyosomal and mitochondrial biogenesis in skeletal muscle biopsies, suggesting an increase in turnover of proteins and damaged organelles (such as mitochondria) which can improve performance and muscular endurance;
- a decrease in the expression of genes linked to the ubiquitin-proteasome system (UPS) and an increase in the expression of genes involved in antioxidant capacities, effects which could help to attenuate muscle atrophy and the harmful impact of oxidative stress on skeletal muscle.
