Table 1 Baseline characteristics of the AS study population

Number of patients

111

Age (yrs)

42.2 ± 10.3

Gender (male) (n, %)

78 (70)

Duration of symptoms (yrs)

16 (1 to 49)

Time since diagnosis (yrs)

9 (0 to 37)

HLA-B27+ (n, %)

88 (81)

History of IBD (n, %)

11 (10)

History of uveitis (n, %)

31 (28)

History of psoriasis (n, %)

9 (8)

Peripheral arthritis (n, %)

21 (19)

Current NSAID use (n, %)

98 (88)

Current DMARD use (n, %)

26 (23)

BASDAI (range 0 to 10)

6.1 ± 1.7

BASDAI ≥ 4 (n, %)

98 (88)

ASDAS_CRP

3.8 ± 0.8

ASDAS_CRP ≥ 2.1 (n, %)

105 (96)

Physician's GDA (range 0 to 10)

5 (1 to 9)

Patient's GDA (range 0 to 10)

7 (1 to 10)

ESR (mm/h)

22 (2 to 90)

Increased ESR (n, %)

86 (78)

CRP (mg/l)

15 (2 to 99)

Increased CRP (n, %)

84 (76)

BASFI (range 0 to 10)

6.1 ± 2.0

Chest expansion (cm)

3.0 (0.5 to 10.0)

Modified Schober test (cm)

2.9 (0.1 to 7.0)

Occiput to wall distance (cm)

5.0 (0.0 to 28.0)

Lateral lumbar flexion L (cm)

8.7 ± 4.1

Lateral lumbar flexion R (cm)

8.4 ± 4.3

ASQoL (range 0 to 18)

10 ± 4

BALP (U/L)

17.2 (1.6 to 36.5)

BALP Z-score

0.28 (-2.59 to 5.16)

PINP (μg/l)

45.6 (16.0 to 98.0)

PINP Z-score

0.35 (-1.75 to 3.63)

sCTX (pg/ml)

206.0 (13.4-657.1)

sCTX Z-score

-0.34 (-2.58 to 4.01)

LS BMD T-score

-0.58 ± 1.41

Osteopenia LS (n, %)

34 (34)

Osteoporosis LS (n, %)

9 (9)

LS BMD Z-score

LS Z-score ≤ -2.0 (n, %)

9 (9)

Hip BMD T-score

-0.53 ± 1.12

Osteopenia hip (n, %)

38 (37)

Osteoporosis hip (n, %)

2 (2)

Hip BMD Z-score

Hip Z-score ≤ -2.0 (n, %)

4 (4)