Sarcopenia Prevalent, Associated With Higher Disease Activity in RA

A high prevalence of sarcopenia was found among patients with rheumatoid arthritis.

Among people with rheumatoid arthritis (RA), sarcopenia is associated with higher RA disease activity, increased falls and fractures, and reduced bone mineral density (BMD), according to study results published in Journal of Clinical Rheumatology.

In a systematic review and meta-analysis, researchers aimed to identify factors associated with sarcopenia in patients with RA.

The systematic review was based on the 2020 guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The authors used the terms “RA” and “sarcopenia” when searching for articles in PubMed, Embase, CINAHL, and Web of Science databases. Articles were eligible for the study if they included patients with RA; assessed sarcopenia based on similar definitions of the condition; and ncluded measures of clinical outcomes.

The initial search yielded 3602 articles. After fulltext reviews, abstract and title screens, and duplicate removals, the authors included 16 studies conducted after 2014. All studies used observational designs, including 12 cross-sectional and 4 prospective cohort studies.

Sarcopenia was found to be prevalent in patients with RA. Depending on the definition criteria, sarcopenia prevalence was between 24% and 30%. Higher 28-joint Disease Activity Scale scores (odds ratio [OR], 0.39; 95% CI, 0.02-0.77) and baseline methotrexate use (OR, 0.70; 95% CI, 0.51–0.97) were associated with sarcopenia.

As a result, early screening and identification of sarcopenia in RA patients, even in younger patients exhibiting signs of reduced muscle mass or function, are important to incorporate into clinical rheumatology practice.

Although glucocorticoid use and sarcopenia prevalence were not statistically significant across all the studies, 6 articles reporting baseline glucocorticoid showed higher use among patients with sarcopenia. More specifically, some studies reported higher doses with sarcopenia than without for cumulative dosages (P =.002) and current doses (P =.002).

Studies assessing falls and fractures were inconsistent or incomplete in reporting their outcome measures, which precluded meta-analyses. However, falls among patients with RA were higher when factoring in the prevalence of sarcopenia (33.1%-46.4%) compared with those without sarcopenia (25.3%-33.3%).

Three studies reported that vertebral fractures were more prevalent among patients with sarcopenia; however, the authors could not perform meta-analyses because of overlaps in the samples.

Patients with sarcopenia and RA also tended to have lower BMD at the lumbar spine (lower by 0.11–0.16 g/cm2) and the femoral neck (lower by 0.11–0.14 g/cm2). Two studies using T-scores reported that hip BMD was lower in patients with sarcopenia (-1.8 and -2.2, respectively) than those without sarcopenia (-1.1 and -1.3, respectively). Another study using multivariate analyses and measuring hip BMD found an association with sarcopenia prevalence (OR, 0.61; 95% CI, 0.38–0.97), when adjusting for other variables.

Limitations of the analysis included sampling bias due to the observational study designs; inconsistent definitions of sarcopenia; and difficulty in comparing studies in their outcome measures.

Study authors concluded, “As a result, early screening and identification of sarcopenia in [patients with] RA, even in younger patients exhibiting signs of reduced muscle mass or function, are important to incorporate into clinical rheumatology practice.”

Disclosure: Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.