Sarcopenia is muscle wasting associated with functional impairment. It results from several factors, such as innervation disorders, physical activity reduction, ageing, metabolic abnormalities (especially in proteins, carbohydrates, and lipids), in addition to changes in the activation of satellite cells. In RA, the following are believed to play a role in the development of sarcopenia: the action of pro-inflammatory cytokines; the reduction in protein synthesis in myocytes; physical activity limitation; insulin resistance; and inadequate protein ingestion.