Table 1 Characteristics of 168 patients with ankylosing spondylitis at baseline and at 5-year follow-up

 Sex, male/female

92 (55)/76 (45)

 Age, years

50 ± 13

55 ± 13

<0.001

 Postmenopausal women

38/76 (50)

47/76 (62)

0.004

 Current smokers

17 (10)

13 (8)

0.4

 Pack years

5.5 ± 10.0

7.0 ± 11.3

< 0.001

 Weight, kg

77 ± 16

79 ± 17

< 0.001

 Height, cm

172 ± 10

171 ± 10

< 0.001

 Time between DXA measurements, months

60.0 ± 2.0

 Duration of symptoms, years

24 ± 13

29 ± 13

< 0.001

 History of anterior uveitis

87 (52)

97 (58)

0.002

 History of peripheral arthritis

98 (58)

106 (63)

0.008

 History of coxitis

13 (8)

17 (10)

0.1

 BASMI, score

3.1 ± 1.6

3.5 ± 1.6

< 0.001

 BASFI, score

2.5 ± 2.0

2.7 ± 2.1

0.1

 BASDAI, score

3.4 ± 2.1

3.5 ± 2.0

0.4

 ASDAS-CRP, score

2.1 ± 0.9

2.1 ± 0.9

0.8

 CRP, mg/L

5.5 ± 8.4

4.7 ± 5.2

0.2

 Mean CRP last 5 years, mg/L

5.8 ± 5.9

 ESR, mm/h

14.2 ± 11.2

11.2 ± 10.4

0.001

 Mean ESR last 5 years, mm/h

12.4 ± 8.7

 mSASSS, score

15.0 ± 20.0

16.6 ± 20.9

< 0.001

 HLA-B27 positive

145 (86)

 Patients on NSAIDs at visit

131 (78)

112 (67)

0.004

 Exposure to NSAIDs during follow-up

145 (86)

 NSAID-index during follow-up, 0–100

34.5 ± 37.1

 Patients on TNFi at visit

33 (20)

38 (23)

0.3

 Exposure to TNFi during follow-up

49 (29)

 Use of TNFi during follow-up, 0–1

0.2 ± 0.4

 Patients on GC at visit

5 (3)

3 (2)

0.6

 Exposure to GC during follow-up

30 (18)

 Patients on bisphosphonate at visit

7 (4)

8 (5)

1.00

 Exposure to bisphosphonate during follow-up

30 (18)

 Use of bisphosphonate during follow-up, 0–1

0.1 ± 0.3

 Patients on MHT at visit

6/76 (8)

4/76 (5)

0.7

 Exposure to MHT during follow-up

9/76 (12)