Comparison of characteristics between non-progressors (ΔmSASSS <1 unit/year) and progressors (ΔmSASSS ≥1 unit/year)
| Variable | Non-progressor (n=66) | Progressor (n=35) | p-value |
|---|---|---|---|
| Age at disease onset (yr) | 26.8±11.5 | 28.3±9.2 | 0.528 |
| Age at estrogen sampling (yr) | 36.3±11.6 | 42.6±8.5 | 0.006 |
| Disease duration (mo) | 37.1±38.4 | 78.4±87.5 | 0.011 |
| Female | 14 (21.2) | 2 (5.7) | 0.048 |
| Peripheral arthritis | 32 (48.5) | 13 (37.1) | 0.275 |
| Hip involvement | 17 (25.8) | 4 (11.4) | 0.123 |
| Uveitis | 18 (27.3) | 9 (25.7) | 0.866 |
| Enthesitis | 9 (13.6) | 5 (14.3) | 0.928 |
| mSASSS, initial | 3.8±4.5 | 16.3±13.4 | <0.001 |
| mSASSS, final | 17.9±20.2 | 21.6±22.7 | 0.445 |
| Sacroiliitis grade |
4.94±1.37 | 6.31±1.62 | <0.001 |
| Estrogen (pg/mL) |
107.7±37.5 | 123.6±35.6 | 0.042 |
| Dkk1 (ng/mL) | 1,303.7±778.9 | 1,001.2±598.7 | 0.048 |
| Leptin (pg/mL) | 1,939.0±1,838.8 | 2,305.4±2,189.4 | 0.375 |
| ESR, initial (mm/h) | 49.1±35.4 | 61.0±27.3 | 0.087 |
| CRP, initial (mg/dL) | 2.31±2.75 | 4.21±4.37 | 0.024 |
| BMI (kg/m2) | 23.1±3.2 | 26.3±3.8 | <0.001 |
| Anti-TNF use | 53 (80.3) | 33 (94.3) | 0.079 |
| Current smoker | 17 (25.8) | 14 (40.0) | 0.140 |
| X-ray follow-up duration (mo) | 93.3±58.3 | 119.1±66.9 | 0.080 |
Data are expressed as mean±standard deviation or number (%). mSASSS: modified Stoke Ankylosing Spondylitis Spine Score, Dkk1: dickkopf-1, ESR: erythrocyte sedimentation rate, CRP: C-reactive protein, BMI: body mass index, TNF: tumor necrosis factor, E2: 17β-estradiol. *Sacroiliitis grade refers to the sum of sacroiliitis grades of the each sides according to the modified New York criteria. †Reference ranges for E2 are 0∼400 pg/mL.