[PURPOSE] The decline in muscle loss with ageing (sarcopenia) may contribute to musculoskeletal disorders. This study aimed to investigate the associations of sarcopenia with rheumatoid arthritis and osteoarthritis in the general population of Korean adults.
[METHODS] We analyzed the data for 11,466 adults aged ≥40 years from the Korea National Health and Nutrition Examination Survey 2008-2011. Skeletal muscle mass was measured using the Dual-energy X-ray absorptiometry. We categorized the participants into four group as high and normal muscle mass, pre-sarcopenia, and sarcopenia group based on the skeletal muscle mass index. Sarcopenia was defined when the appendicular skeletal muscle index was less than the sex-specific average minus the two standard deviations (SD) in the young reference group (age, 20-39 years). The associations of sarcopenia with rheumatoid arthritis and osteoarthritis were evaluated using survey logistic regression analysis.
[RESULTS] Sarcopenia status was dose-dependently associated with a higher risk of rheumatoid arthritis, after adjustment for potential confounders (P-trend=0.002). The odds ratio (OR) for rheumatoid arthritis was 2.14 (95% confidence interval [CI], 1.13-4.05) in sarcopenia group compared with the high muscle mass group. The higher risk of osteoarthritis was observed in pre-sarcopenia group compared with the high muscle mass group (OR, 1.45; 95% CI, 1.03-2.05), but not in sarcopenia group.
[CONCLUSIONS] We found that sarcopenia status was associated with the higher risk for rheumatoid arthritis and osteoarthritis. Our findings suggest that maintaining a skeletal muscle mass could be beneficial in preventing musculoskeletal disorders, including rheumatoid arthritis and osteoarthritis.