Sarcopenia-associated factors in Japanese patients with rheumatoid arthritis: A cross-sectional study

To evaluate the prevalence rate and factors associated with sarcopenia in Japanese patients with rheumatoid arthritis.

We enrolled 240 consecutive patients with rheumatoid arthritis aged ≥65 years in this study. We examined clinical data: age, sex, body mass index, disease duration, rheumatoid factor positivity, anti-cyclic citrullinated peptide antibody positivity, biological or target synthetic disease-modifying antirheumatic drug use, methotrexate use, glucocorticoid use, C-reactive protein level, disease activity score in 28 joints-erythrocyte sedimentation rate, Health Assessment Questionnaire Disability Index, bone mineral density of the lumbar spine and total hip, grip strength, gait speed, and relative skeletal muscle mass index by bioelectrical impedance analysis. Sarcopenia was defined according to a consensus report by the Asian Working Group for Sarcopenia.

The prevalence rate of sarcopenia was found to be 29.6%. Multivariate analysis identified the following factors to be associated with sarcopenia: age (P = 0.008; odds ratio 1.08), body mass index (P < 0.001; odds ratio 0.73), C-reactive protein (P = 0.017; odds ratio 1.76) and hip bone mineral density (P = 0.037; odds ratio 0.61).

The sarcopenia-associated factors were age, body mass index, C-reactive protein and hip bone mineral density in Japanese patients with rheumatoid arthritis. Because the Health Assessment Questionnaire Disability Index, a standard measurement of function, cannot predict sarcopenia, the muscle mass needs to be measured while assessing changes in grip strength, body mass index, C-reactive protein and hip bone mineral density. Geriatr Gerontol Int 2019; 19: 907-912.