Table 2.
Comparison of clinical characteristics between RA patients with and without low muscle mass in the univariable analysis.
| RA+low muscle mass SMI < 5.5 kg/m2 n = 86 |
RA+normal muscle mass SMI ≥ 5.5 kg/m2 n = 75 |
p value | |
|---|---|---|---|
| Age, median (range) | 57.5 (18-80) | 59.0 (24-89) | 0.80 |
| Menopause, n (%) | 74 (86) | 58 (77) | 0.15 |
| Sedentary, n (%) | 57 (66) | 48 (64) | 0.76 |
| BMI (kg/m2), median (range) | 23.5 (16.5-36.7) | 29.3 (21.4-39.5) | <0.001 |
| Disease duration, median (range) | 12 (1-40) | 8 (1-35) | 0.02 |
| Deteriorated functional class (II-IV), n (%) | 69 (80) | 45 (60) | 0.005 |
| DAS28-ESR ≥ 3.2 | 41 (48) | 19 (25) | 0.003 |
| Rheumatoid cachexia, n (%) | 24 (28) | 6 (8) | 0.001 |
| Myostatin (ng/mL), median (range) | 13.54 (1.88-140) | 10.02 (1.2-117) | 0.02 |
| High myostatin levels (≥17 ng/mL) | 37 (43) | 17 (23) | 0.006 |
DAS28-ESR: Disease Activity Score (28 joints), Erythrocyte Sedimentation Rate. DAS28-ESR ≥ 3.2 indicates moderate or severe disease activity in RA patients. Quantitative variables expressed in medians and ranges and compared by Mann-Whiney U tests; qualitative variables expressed in frequency and % and compared by chi-square tests.