Demographic and clinical characteristics of the study cohort. Results are expressed as mean ± SD or median (interquartile range) unless otherwise indicated.
| Variables | Cases (SDI > 0; n = 78) | Comparative Group (SDI = 0; n = 72) | p |
|---|---|---|---|
| Age, yrs | 45.3 ± 9.6 | 43.1 ± 8.8 | 0.15 |
| Height, m | 1.6 ± 0.06 | 1.58 ± 0.05 | 0.17 |
| Weight, kg | 55.3 ± 9.1 | 57.8 ± 11 | 0.13 |
| Body mass index, kg/m2 | 22.5 ± 3.7 | 23.2 ± 4.2 | 0.36 |
| Postmenopausal, n (%) | 42 (53.8) | 28 (38.9) | 0.07 |
| Duration of menopause, yrs | 4 (2, 10) | 2 (1, 6) | 0.06 |
| Currently smoking, n (%) | 4 (5.9) | 5 (6.9) | 0.74 |
| Aerobic exercise ≥ 40 min/wk, n (%) | 17 (21.8) | 25 (34.7) | 0.08 |
| History of fracture, n (%) | 5 (6.4) | 5 (6.9) | 0.86 |
| Family history of osteoporosis, n (%) | 5 (6.4) | 3 (4.2) | 0.72 |
| Family history of fracture, n (%) | 12 (15.4) | 14 (19.4) | 0.51 |
| Clinical characteristics | |||
| Disease duration, yrs | 13.6 (7.1, 18.6) | 10.4 (5.7, 15) | 0.01 |
| SLEDAI | 2 (0, 4) | 2 (0, 4) | 0.58 |
| SDI | 1 (1, 2) | 0 | < 0.001 |
| Neuropsychiatric damage, n (%) | 20 (25.6) | 0 | < 0.001 |
| Ocular damage, n (%) | 19 (24.4) | 0 | < 0.001 |
| Pulmonary damage, n (%) | 11 (14.1) | 0 | < 0.001 |
| Musculoskeletal damage, n (%) | 11 (14.1) | 0 | < 0.001 |
| Arthritis, n (%) | 40 (51.3) | 47 (65.3) | 0.08 |
| Nephritis, n (%) | 52 (66.7) | 48 (66.7) | 1 |
| 25(OH)d, nmol/l | 48.5 ± 11.1 | 47.9 ± 12.5 | 0.72 |
SLEDAI: Systemic Lupus Erythematosus Disease Activity Index; SDI: Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; 25(OH)D: 25-hydroxyvitamin D.