Baseline characteristics in patients with and without axSpA, stratified by gender
| axSpA N=168 | no-axSpA N=260 | |||
|---|---|---|---|---|
| Male n=81 | Female n=87 | Male n=77 | Female n=183 | |
| Age, mean (SD), years | 29.9 (8.0) | 30.5 (8.5) | 30.7 (8.7) | 32.2 (8.3) |
| HLA-B27+, n (%) | 77 (95.1) | 79 (90.8) | 11 (14.5) | 13 (7.1) |
| BMI, mean (SD) | 24.6 (4.1)ŧ | 24.4 (6.7)ŧ | 24.9 (3.8) | 25.7 (5.5) |
| Underweight (≤18.5), n (%) | 2 (2.5) | 4 (4.6) | 3 (3.9)ŧ | 5 (2.7)ŧ |
| Normal (18.5–24.9), n (%) | 53 (65.4) | 58 (66.7) | 36 (46.7)ŧ | 97 (53)ŧ |
| Overweight (25–29.9), n (%) | 18 (22.2) | 13 (14.9) | 33 (42.9)ŧ | 49 (26.8)ŧ |
| Obese (≥30), n (%) | 8 (9.9) | 12 (13.8) | 5 (6.5)ŧ | 32 (17.5)ŧ |
| CRP (mg/L) median (IQR), (range)* | 3 (3–6) (0–59) | 3 (2–7) (0.2–46) | 3 (3–4) (0.4–96) | 3 (3–6) (0–46) |
| CRP ≥5, n (%) | 26 (32.1) | 29 (33.3) | 19 (24.7)ŧ | 70 (38.3)ŧ |
| ESR (mm/h), median (IQR), (range). | 6 (2–11) (1–67)§ | 10 (6–18) (2–87)§ | 2 (2–9) (1–65)§ | 9 (5–14) (2–66)§ |
| Physician global, mean (SD) | 5.1 (2.5) | 5.3 (2.4) | 5.0 (2.4) | 4.9 (2.3) |
| Patient's global, mean (SD)* | 3.8 (2.6) | 4.5 (2.6) | 4.9 (2.7) | 5.3 (2.7) |
| Total back pain, mean (SD)* | 4.5 (2.6) | 4.9 (2.7) | 4.5 (2.6)§ | 5.7 (2.7)§ |
| Peripheral pain/swelling, mean (SD)* | 2.1 (2.6) | 2.7 (3.0) | 2.4 (2.7)§ | 3.7 (3.1)§ |
| Duration of morning stiffness, mean (SD)* | 3.7 (2.9) | 3.9 (2.8) | 4.0 (3.1) | 4.4 (2.9) |
| ASDAS-CRP, mean (SD) | 2.3 (0.9)† | 2.5 (0.9)† | ||
| BASDAI, mean (SD) | 3.6 (2)ŧ | 4.3 (2.2)ŧ | ||
§p<0.001, ŧp<0.05.
*ASDAS-CRP p value=0.18.
†Parameters of ASDAS-CRP.
ASDAS, Ankylosing Spondylitis Disease Activity Score; axSpA, axial spondyloarthritis; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BMI, body mass index CRP, C reactive protein; ESR, erythrocyte sedimentation rate; HLA-B27, human leucocyte antigen B27.