Risk Factors and Clinical Outcomes Associated With Sarcopenia in Rheumatoid Arthritis

Abstract

Sarcopenia is underrecognized in patients with rheumatoid arthritis (RA). Risk factors of sarcopenia and its impact on outcomes in RA patients are relatively unknown. We conducted a systematic review to identify factors and outcomes associated with sarcopenia in RA. We conducted this review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. We searched PubMed, Embase, CINAHL, and Web of Science databases by combining the following search concepts: (1) RA and (2) sarcopenia. Articles were included if they included RA patients, assessed for sarcopenia using a consensus working group definition, and assessed for clinical outcomes. Meta-analysis was performed using studies that shared the same sarcopenia definition and consistency in reporting patient or disease variables. Our search identified 3602 articles. After removal of duplicates, title and abstract screen, and full-text review, 16 articles were included for final analysis. All studies had observational study designs. The pooled prevalence of sarcopenia ranged from 24% to 30%, depending on the criteria for sarcopenia used. Factors associated with sarcopenia included higher 28-joint Disease Activity Scale scores (+0.39; 95% confidence interval, +0.02 to +0.77) and baseline methotrexate use (odds ratio, 0.70; 95% confidence interval, 0.51-0.97). Baseline glucocorticoid use had a positive correlation with sarcopenia in multiple studies. Several studies found lower bone mineral density and higher incidence of falls and fractures in patients with sarcopenia. Sarcopenia is prevalent in RA, and it may be associated with higher RA disease activity, lower bone mineral density, and increased falls and fractures. Therefore, early screening of sarcopenia in RA patients is important to incorporate into clinical rheumatology practice.

Adipokines in Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

“…A meta-analysis by Dao et al [113] found that in adults with RA, glucocorticoid use was positively associated with sarcopenia. However, a recent meta-analysis by Tam et al [114] did not identify a statistically significant relationship between baseline glucocorticoid administration and sarcopenia. Nevertheless, six out of seven studies reported elevated rates of glucocorticoid administration among RA patients with sarcopenia [8][9][10][11][12][13], with three studies indicating a significant difference [8,9,12].…”

“…In their meta-analysis, Tam et al [114] identified several studies that established a correlation between sarcopenia and increased disease activity in RA patients [120][121][122][123]. Upon pooled analysis, this association was found to include greater DAS28 scores among patients with sarcopenia [114].…”

“…In their meta-analysis, Tam et al [114] identified several studies that established a correlation between sarcopenia and increased disease activity in RA patients [120][121][122][123]. Upon pooled analysis, this association was found to include greater DAS28 scores among patients with sarcopenia [114]. The authors suggested that this correlation likely indicates a bidirectional relationship, as heightened disease activity may trigger the onset of sarcopenia through disability and inflammatory pathways [114,124].…”

Drug‐related sarcopenia as a secondary sarcopenia

“…38 Thus, long-term use of glucocorticoids has been reported to induce sarcopenia, which is a risk for falls. 39 Glucocorticoid-induced muscle atrophy is more likely to occur in fast-twitch muscles (type II fibers), which are rich in glucocorticoid receptors, and muscles with mixed fibers, in which both types of fibers are mixed, are also more likely to atrophy than type I fibers. The mechanism of muscle atrophy is that glucocorticoid inhibits muscle protein anabolism and enhances catabolism via its receptors in muscle, thereby inducing a decrease in muscle protein content.…”

“…These glucocorticoid‐induced myopathies are not accompanied by myalgia or elevated serum CK, and muscle atrophy and weakness begin in the proximal muscles of the lower extremities and extend to the proximal and distal parts of the upper extremities (Table 1). 38 Thus, long‐term use of glucocorticoids has been reported to induce sarcopenia, which is a risk for falls 39 …”