Table 1 Demographic and disease-specific characteristics of patients with nonradiographic axial spondyloarthritis and healthy control subjects

 Female sex, n (%)

42 (41.6)

20 (40)

0.852

 Age, yr

45.0 (15.0)

44.76 (26.0)

0.917

 Height, m

1.74 (0.1)

1.74 (0.1)

0.997

 Weight, kg

81.1 (21.5)

76.0 (18.5)

0.054

 Body mass index, kg/m²

26.3 (6.5)

23.8 (5.2)

0.118

 Current or previous smoking, n (%)

38 (37.6)

11 (24.4)

0.119

 HLA-B27 positivity, n (%)

75 (75.0)

–

–

 Duration of disease, yr

6.5 (9.0)

–

–

 Disease remission, n (%)

15 (14.9)

–

–

 ASDAS-CRP, units

2.1 (1.4)

–

–

 BASDAI, units

3.5 (3.6)

–

–

 C-reactive protein, mg/L

6.2 (4.0)

–

–

 ESR, mm

12.7 (10.5)

–

–

 BASFI, units

2.9 (3.8)

–

–

 BASMI, units

1.1 (2)

–

–

 Peripheral arthritis, n (%)

35 (34.7)

–

–

 Dactylitis, n (%)

2 (2.0)

–

–

 Enthesitis, n (%)

17 (16.8)

–

–

 MASES, units

1.1 (1)

–

–

 Psoriasis, n (%)

13 (12.9)

–

–

 Uveitis, n (%)

8 (7.9)

–

–

 Inflammatory bowel disease, n (%)

7 (6.9)

–

–

 Low trauma fracture, n (%)

7 (6.9)

–

–

 25(OH)vitamin D₃, ng/ml

32.4 (16.3)

–

–

 Current biologic therapy^a, n (%)

59 (58.4)

–

–

 Duration of biologic therapy, yr

2.0 (4.0)

 Current DMARD therapy^b, n (%)

28 (27.7)

–

–

 NSAID, n (%)

68 (67.3)

–

–

 NSAID daily, n (%)

22 (21.8)

–

–

 NSAID on demand, n (%)

46 (45.5)

–

–

 Prednisolone ≥ 5 mg > 3 months^c, n (%)

32 (31.7)

–

–

 Calcium substitution, n (%)

8 (7.9)

–

–

 25(OH)vitamin D₃ substitution, n (%)

26 (25.7)

–

–

 Antiresorptive treatment, n (%)

5 (5.0)

–

–