Prevalence of Sarcopenia and Whole-Body Composition in Rheumatoid Arthritis

Abstract

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease that leads to joint deformity and disability, as well as muscle involvement. Sarcopenia is characterized by a progressive age-related loss of muscle mass and strength.

Aim: The aim of this study was to evaluate the prevalence of sarcopenia and possible contributing factors associated with sarcopenia in RA patients.

Patients and methods: Adult RA patients (n = 105) of both sexes and 100 subjects as control group (CG) matched by age, sex, and body mass index were included in this cross-sectional study. Whole-body composition was measured by dual-energy x-ray absorptiometry. Sarcopenia was defined according to European Working Group on Sarcopenia in Older People 2 as low muscle strength (handgrip) and low muscle mass (appendicular skeletal muscle mass [ASM] index by dual-energy x-ray absorptiometry). The association between sarcopenia and associated factors was evaluated using logistic regression analyses.

Results: Significantly lower percentage of lean mass and ASM were found in the whole RA group compared with controls. However, lower lean parameters (total lean mass, percentage of lean mass, and ASM) were observed only in female subjects. The ASM index was significantly lower in female subjects with RA (RA 31.0% vs CG 11.9%) without differences in male subjects. On the other hand, fat mass and most adipose indices were significantly higher in both female and male subjects with RA. Female RA patients had higher prevalence of sarcopenia and sarcopenic obesity. Through univariate logistic regression analysis, the time of corticosteroids use, cumulative corticosteroid dose, previous fragility fractures, total lean mass, and ASM were associated with sarcopenia.

Conclusions: Higher prevalence of sarcopenia and sarcopenic obesity were found in female RA patients. Sarcopenia was found in younger female subjects with RA compared with healthy control subjects. Sarcopenia was associated with previous fragility fractures in female patients with RA.