TNF and rheumatoid arthritis: These findings are consistent with those reported elsewhere [22], which highlight the major role of inflammation and fatty tissue in the pathogenesis of sarcopenia in RA: adipocytes undergo hypertrophy and hyperplasia and behave like an inflammatory tissue that produces excess levels of proinflammatory mediators, such as TNF-α, IL-12 and IL-6 [59,60], and leptin [16].