Using a multiple regression analysis, male sex (odds ratio (OR) 140.65, p < 0.001), BMI (OR 0.41, p < 0.001), and use of tumor necrosis factor (TNF) inhibitors (OR 4.84, p = 0.037) were associated with a low muscle mass in RA patients, while the presence of erosion, DAS28, cumulative dose of glucocorticoids, and osteoporosis were not (Table 4). The gene discussed is TNF; the disease is rheumatoid arthritis.