Associations of Sarcopenia with Rheumatoid Arthritis and Osteoarthritis in Korean Adults: the Korea National Health and Nutrition Examination Survey 2008-2011. The Journal of Kinesiology, 2017, 19(3): 61-70. [PURPOSE] 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. Dual-energy X-ray absorptiometry was used to measure the skeletal muscle mass. Sarcopenia was defined when the appendicular skeletal muscle index was less than the sex-specific average minus the two standard deviations in the young reference group(age, 20-39 years). Survey logistic regression analysis was used to assess the association of sarcopenia with rheumatoid arthritis and osteoarthritis. [RESULTS] Sarcopenia status was dose-dependently associated with a higher risk of rheumatoid arthritis, after adjustment for potential confounders(p-trend=.002, odds ratio [OR], 2.14; 95% confidence interval [CI], 1.13, 4.05 in sarcopenia group vs. high muscle mass group). However, a 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 rheuma-toid arthritis, and pre-sarcopenia status was associated with osteoarthritis. Our findings suggest that maintaining a skeletal muscle could be beneficial in preventing musculoskeletal disorders, including rheumatoid arthritis and osteoarthritis.