Table 1.
Baseline characteristics of the patients with ankylosing spondylitis.
| Variable | AS Patients (n = 219) | Healthy Controls (n = 219) | p-Value |
|---|---|---|---|
| Demographics | |||
| Age, mean (SD), years | 47.6 (13.8) | 47.5 ± 13.7 | 0.972 |
| Sex, N (%) | |||
| Men | 144 (65.8) | 144 (65.8) | |
| Women | 75 (34.2) | 75 (34.2) | |
| Menopause, N (%) | 43 (57.3) | 40 (53.3) | 0.628 |
| Bodyweight, mean (SD), kg | 64.3 (12.2) | 66.4 (11.3) | 0.71 |
| Height, mean (SD), cm | 163.9 (10.1) | 165.6 (8.41) | 0.06 |
| Body mass index, mean (SD), kg/m2 | 23.9 (3.7) | 24.3 (3.09) | 0.227 |
| Smoking, N (%) | 53 (24.2) | 41 (18.7) | 0.082 |
| Alcohol, N (%) | 53 (24.2) | 68 (31.1) | 0.225 |
| Fractures, N (%) | 25 (11.4) | 3 (1.7) | <0.001 * |
| Vertebral fractures, N (%) | 20 (9.1) | 3 (1.7) | <0.001 * |
| Non-vertebral fractures, N (%) | 5 (2.3) | 0 (0) | 0.025 * |
| Disease-related | |||
| Disease duration, mean (SD), months | 48.6 (46.6) | ||
| HLA-B27-positive, N (%) | 183 (83.6) | ||
| ESR, mm/h, median (IQR) | 31 (13–59) | ||
| CRP, mg/dL, median (IQR) | 1.57 (0.39–3.02) | ||
| Peripheral arthritis, N (%) | 84 (38.4) | ||
| Enthesopathy, N (%) | 25 (11.4) | ||
| Uveitis, N (%) | 34 (15.5) | ||
| Syndesmophyte, N (%) | 88 (40.2) | ||
| mSASSS score, median (IQR) | 13 (5–32) | ||
| Medications | |||
| NSAIDs, N (%) | 190 (86.8) | ||
| Methotrexate, N (%) | 59 (26.9) | ||
| Sulfasalazine, N (%) | 137 (62.6) | ||
| TNF inhibitor, N (%) | 98 (44.7) | ||
| GC, N (%) | 69 (31.5) | ||
| GC lifetime use, mean (SD), g (prednisone-equivalent dose) | 10.7 (2.04) | ||
| GC current dose, mean (SD), mg/d | 1.69 (3.13) | ||
| Vitamin D intake, N (%) | 105 (47.9) | ||
| Calcium intake, N (%) | 89 (40.6) | ||
| Proton pump inhibitor, N (%) | 51 (23.3) | ||
| Treatment for osteoporosis, N (%) | 33 (15.1) | ||
| Bisphosphonate, N (%) | 24 (11) | ||
| SERM, N (%) | 6 (2.7) | ||
| Denosumab, N (%) | 3 (1.4) |
AS, ankylosing spondylitis; HLA, human leukocyte antigen; ESR, erythrocyte sedimentation rate; IQR, interquartile range; CRP, C-reactive protein; mSASSS, modified Stoke Ankylosing Spondylitis Score; NSAIDs, non-steroidal anti-inflammatory drugs; TNF, tumor necrosis factor; GC, glucocorticoid; SERM, selective estrogen receptor modulators; * p < 0.05.