Table 1 Baseline characteristics of the study patients (n= 102 at baseline, n= 75 at 2 years))

Age

35.54±8.69

–

erum uric acid,mg/dl

6.62±1.52

6.39±1.39

hyperuricemia no. (%)

34 (33.33%)

22 (29.33%)

HLA–B27 positive, no. (%)

85 (83.33)

–

Symptom duration, years

11.25±8.15

–

History of uveitis, no. (%)

11 (10.78)

–

History of psoriasis, no. (%)

0 (0)

–

History of IBD, no. (%)

2 (1.96)

–

History of peripheral arthritis, no. (%)

16 (15.68)

–

csDMARDs use, no. (%)

60 (58.82)

–

NSAID use, no. (%)

59 (57.84)

–

TNFi use, no. (%)

23 (22.55)

–

 PtGA,0–100

17.86±18.82

13.01±15.26

 Spinal pain ,0–100

15.09±15.29

12.37±18.1

 Spinal pain in ninght,0–100

13.34±16.18

11.09±17.78

 BASDAI,0–10

1.41±1.29

1.06±0.96

 BASFI,0–10

0.61±0.96

0.43±0.69

 ASDAS-CRP

1.31±0.75

1.37±0.67

 SF-36:PF (Physical Functioning)

87.64±14.46

91.66±10.42

 SF-36:RP (Role-Physical)

69.85±40.77

77.45±38.48

 SF-36:BP (Bodily Pain)

72.66±13.58

75.92±14.04

 SF-36:GH (General Health)

57.3±19.31

60.94±21.41

 SF-36:VT (Vitality)

65.14±13.99

62.64±10.59

 SF-36:SF (Social Functioning)

89.46±18

89.7±20.57

 SF-36:RE (Role-Emotional)

73.52±38.2

79.73±35.94

 SF-36:MH (Mental Health)

50.5±14.03

61.56±12.75

 CRP (mg/liter)

5.02±6.59

6.56±7.31

 ESR (mm/h)

10.18±10.35

8.95±7.3