Comparison between the study group and the control group at baseline. Values are mean (SD) or % unless otherwise specified.
| Characteristics | Study Group, n = 42 | Control Group, n = 47 | p |
|---|---|---|---|
| Age, yrs | 39.6 (7.5) | 41.9 (8.7) | 0.385 |
| Male | 88 | 85 | 0.758 |
| Smoking | 28 | 35 | 0.452 |
| Disease duration, mos | 16.4 (4.8) | 17.5 (5.9) | 0.541 |
| BMI, kg/m2 | 22.5 (2.72) | 23.3 (3.01) | 0.221 |
| Extraarticular manifestations | 14 | 15 | 0.652 |
| Current use of NSAID | 33 | 59 | 0.0001 |
| HLA-B27–positive | 95 | 91 | 0.921 |
| ESR, mm/h | 29 (23) | 33 (21) | 0.318 |
| CRP, mg/l | 21.4 (16.64) | 25.3 (18.72) | 0.478 |
| BASDAI | 5.84 (1.80) | 5.06 (1.27) | 0.397 |
| BASFI | 4.87 (1.96) | 4.39 (2.14) | 0.480 |
| mSASSS | 19.8 (23.4) | 18.4 (21.7) | 0.280 |
| Lumbar spine BMD Z score | −2.05 (1.01) | −1.97 (0.94) | 0.119 |
| Femoral neck BMD Z score | −1.98 (0.92) | −2.17 (1.12) | 0.194 |
| BALP, U/l, median (IQR) | 17.5 (2.8–38.6) | 14.8 (3.5–35.1) | 0.235 |
| PINP, ug/l, median (IQR) | 43.1 (15.1–84.3) | 45.9 (16.4–95.6) | 0.319 |
| sCTX, pg/ml, median (IQR) | 246.0 (33.7–734.5) | 223.5 (23.1–687.4) | 0.124 |
BMI: body mass index; NSAID: nonsteroidal antiinflammatory drugs; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; BASDAI: Bath AS Disease Activity Index; BASFI: Bath AS Functional Index; mSASSS: modified Stoke AS Spine Score; BMD: bone mineral density; BALP: bone-specific alkaline phosphatase; IQR: interquartile range; PINP: procollagen type-I N-terminal peptide; sCTX: serum C-telopeptides of type-I collagen; AS: ankylosing spondylitis.