How much disability in rheumatoid disease is due to associated muscle loss? Especially for older patients, says a review of the condition, vigilance for sarcopenia is warranted.
Cruz-Jentoft AJ, Landi F, Schneider SM, et al., Prevalence of and interventions for sarcopenia in ageing adults: a systematic review. Report of the International Sarcopenia Initiative (EWGSOP and IWGS). Age Ageing (2014) doi: 10.1093/ageing/afu115 First published online: September 21, 2014.
Sarcopenia, the loss of skeletal muscle mean mass and strength often associated with older age, can also occur in rheumatic diseases as a result of disuse of muscles and avoidance of activity due to joint pain and difficulty with movement. This new review describes the consequences and possible treatments for sarcopenia, and contends that screening for the condition in the general ageing population is justified.
There is also reason from previous reports to support being alert for sarcopenia among patients with rheumatic diseases. A 2008 study from Johns Hopkins observed that 66% of patients with rheumatoid arthtritis (RA) have some loss of cell mass (mostly skeletal muscle tissue), while other researchers have found that women with RA have 6 times the normal odds of sarcopenia, especially those not receiving disease modifying antirheumatic drugs (DMARDs).
Data presented at the American College of Rheumatology annual meeting last year showed an increased risk of sarcopenia among patients and others with autoimmune diseases, independently associated with joint damage and joint deformity. Apart from disease-related functional diasbility, in RA sarcopenia can also lead to physical frailty.
Additionally, a 2012 report from Brazil asserted that the action of pro-inflammatory cytokines, a reduction in protein synthesis in myocytes, insulin resistance, inadequate protein intake and deficiencies in muscle regeneration, may play a role in rheumatoid sarcopenia.
The Age and Ageing review notes that sarcopenia in any setting is associated with disability, loss of daily function, poor quality of life, and even early death. There are few remedies other than supervised resistance exercise and, perhaps, essential amino acid supplements.
However, there’s some suggestion that biologic therapies for RA and other rheumatic diseases, such as tumor necrosis factor-alpha (TNF-Î±) inhibitors, may help.
One randomized trial of TNF-Î± blockers found that etanercept (Enbrel) is associated with a gain in lean muscle mass in a subset of patients with early RA. The Johns Hopkins researchers said that this finding “raises the question as to whether anti–tumor necrosis factor therapy has a direct anabolic effect on muscle or exerts its effects indirectly by reducing RA disease activity and pain, thus enabling increased physical functioning and activity.”
“Physicians should screen for sarcopenia in both community and geriatric settings, with diagnosis based on muscle mass and function,” the Age and Aging review concludes.