Baseline characteristics of patients with rheumatoid arthritis (n = 138) stratified for thyroid group. Continuous variables are presented as means with SD in cases of normal distribution or as medians with interquartile ranges in cases of non-normal distribution.
| Characteristics | Hypothyroid, n = 18 | Euthyroid, n = 113 | Hyperthyroid, n = 7 | p† | p* |
|---|---|---|---|---|---|
| Age, yrs | 57 ± 11 | 54 ± 12 | 56 ± 10 | 0.29 | 0.64 |
| Women, % | 78 | 75 | 100 | 1.0 | 0.20 |
| Disease duration, yrs | 8 (6–18) | 7 (3–15) | 8 (3–22) | 0.19 | 0.86 |
| IgM RF-positive, % | 56 | 55 | 86 | 0.99 | 0.24 |
| IgM RF levels, IU/ml | 40 (14–142) | 35 (11–72) | 68 (31–105) | 0.47 | 0.19 |
| ACPA-positive, % | 83 | 73 | 86 | 0.56 | 0.68 |
| ACPA levels, AU/ml | 1320 (158–3300) | 402 (33–1550) | 1000 (218–2210) | 0.12 | 0.41 |
| Erosive disease, % | 78 | 81 | 86 | 0.76 | 1.0 |
| Current prednisone use, % | 50 | 28 | 86 | 0.065 | 0.0040 |
| Prednisone dosage, mg/day | 3 (0–10) | 0 (0–5) | 5 (4–6) | 0.020 | 0.011 |
| Current MTX use, % | 78 | 78 | 86 | 1.0 | 1.0 |
| MTX dosage, mg/wk | 15 (4–25) | 20 (10–25) | 15 (7.5–25) | 0.23 | 0.38 |
| No. DMARD used | 4 (3–4) | 3 (2–3) | 3 (2–6) | 0.066 | 0.47 |
| DAS28 | 5.2 ± 1.4 | 5.1 ± 1.1 | 5.4 ± 1.4 | 0.65 | 0.47 |
| ESR, mm/h | 24 (17–56) | 22 (11–41) | 17 (9–26) | 0.46 | 0.60 |
| CRP, mg/l | 13 (7–32) | 12 (6–27) | 18 (7–40) | 0.76 | 0.47 |
↵† Hypothyroid vs euthyroid.
↵* Hyperthyroid vs euthyroid vs euthyroid. RF: rheumatoid factor; ACPA: anti-citrullinated protein antibody; MTX: methotrexate; DMARD: disease-modifying antirheumatic drug; DAS28: 28-joint count Disease Activity Score; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; AU: arbitrary units.