Comparison of clinical variables according to SDI scores. Values are median (interquartile range) unless otherwise specified.
| Characteristics | SDI = 0, n = 396 | SDI ≥ 1, n = 106 | p |
|---|---|---|---|
| Age, yrs | 38.5 (31.0–46.8) | 40.5 (33.0–48.0) | 0.127 |
| Disease onset age, yrs | 29.2 (20.4–38.1) | 28.7 (19.5–37.9) | 0.739 |
| Female, n (%) | 374 (94.4) | 95 (89.6) | 0.075 |
| Disease duration, yrs | 7.5 (3.5–13.4) | 9.7 (4.6–14.6) | 0.072 |
| Education duration, yrs | 14.0 (12.0–16.0) | 12.0 (12.0–16.0) | 0.054 |
| Employed, n (%) | 188 (47.5) | 47 (44.3) | 0.566 |
| Family history of rheumatic diseases, n (%) | 43 (10.9) | 10 (9.4) | 0.672 |
| Alcohol consumption, n (%) | 112 (28.3) | 30 (28.3) | 0.997 |
| Smoking status, n (%) | 0.182 | ||
| Never smoker | 357 (90.2) | 90 (84.9) | |
| Current smoker | 27 (6.8) | 9 (8.5) | |
| Ex-smoker | 12 (3.0) | 7 (6.6) | |
| Height, cm | 160.0 (156.0–164.0) | 160.0 (155.0–164.0) | 0.424 |
| Weight, kg | 55.0 (50.0–60.0) | 55.0 (50.0–64.0) | 0.332 |
| BMI, kg/m2 | 21.2 (19.4–23.5) | 22.0 (19.7–24.6) | 0.084 |
| Waist circumference, cm | 73.0 (66.0–80.0) | 74.5 (68.0–84.0) | 0.072 |
| Hip circumference, cm | 90.5 (85.0–96.0) | 90.0 (85.0–96.0) | 0.910 |
| SBP, mmHg | 117.0 (109.0–126.0) | 120.0 (110.0–129.5) | 0.091 |
| DBP, mmHg | 70.0 (65.0–79.0) | 72.0 (65.5–80.0) | 0.542 |
| BDI | 7.0 (3.0–12.0) | 9.0 (5.0–16.0) | 0.004 |
| SF-36 health survey | |||
| PCS | 49.1 (42.9–53.8) | 47.2 (39.7–53.9) | 0.116 |
| MCS | 50.4 (41.5–56.1) | 47.9 (37.6–55.2) | 0.041 |
| PGA | 1.0 (0.5–1.0) | 1.0 (0.5–1.2) | 0.093 |
| SLEDAI | 2.0 (1.0–4.8) | 4.0 (2.0–8.0) | 0.002 |
| CCIa | 1.0 (1.0–1.8) | 1.0 (1.0–3.0) | 0.012 |
| ESR, mm/h | 20.0 (10.0–31.0) | 19.0 (9.8–36.0) | 0.507 |
| CRP, mg/dl | 0.08 (0.06–0.30) | 0.18 (0.06–0.50) | 0.002 |
| Anti-dsDNA positivity, n (%) | 208 (52.5) | 61 (58.1) | 0.309 |
| Complement 3, mg/dl | 79.3 (67.0–95.1) | 78.2 (65.4–97.6) | 0.746 |
| Complement 4, mg/dl | 15.4 (10.4–20.3) | 14.1 (10.1–21.8) | 0.726 |
| CH50, U/ml | 47.6 (36.9–56.7) | 48.8 (38.2–56.7) | 0.921 |
| Corticosteroid, mg/day | 5.8 (5.0–8.8) | 8.1 (5.0–10.2) | < 0.001 |
SDI: Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; BMI: body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; BDI: Becker Depression Inventory; SF-36: Medical Outcomes Study Short Form-36; PCS: physical component score; MCS: mental component score; PGA: physician’s global assessment; SLEDAI: The Systemic Lupus Erythematosus Disease Activity Index; CCIa: age-adjusted Charlson Comorbidity Index; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein.