Background
Methods
Patients
Physical examination and questionnaires
Bone mineral density
Radiography
Laboratory tests
Statistics
Results
Patients
Baseline | 5-year follow-up |
p value | |
---|---|---|---|
Demographic variables | |||
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 | ||
Disease-related variables | |||
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) | ||
Medications | |||
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) |
Five-year BMD changes
Prevalence of low BMD
Measuring site | Group | Patients with osteoporosis/BMD below expected range for age |
p value | |
---|---|---|---|---|
Baseline | 5-year follow-up | |||
Any measuring site | Total | 39 (23) | 45 (27) | 0.24 |
Men | 12 (13)** | 16 (17)** | 0.29 | |
Women | 27 (36) | 29 (38) | 0.75 | |
Femoral neck | Total | 10 (6) | 12 (7) | 0.72 |
Men | 6 (7) | 7 (8) | 1.00 | |
Women | 4 (5) | 5 (7) | 1.00 | |
Total hip | Total | 1 (1) | 1 (1) | 1.00 |
Men | 1 (1) | 1 (1) | 1.00 | |
Women | 0 (0) | 0 (0) | – | |
Spine AP | Total | 16 (10) | 12 (7) | 0.39 |
Men | 4 (4)* | 2 (2)** | 0.69 | |
Women | 12 (16) | 10 (13) | 0.69 | |
Spine lateral | Total | NA | NA | NA |
Men | NA | NA | NA | |
Women | 20 (26) | 18 (24) | 0.63 | |
Total radius | Total | 13 (8) | 20 (12) |
0.04
|
Men | 7 (8) | 11 (12) | 0.13 | |
Women | 6 (8) | 9 (12) | 0.38 |
Site | Group | Baseline BMD, g/cm2
| Follow-up BMD, g/cm2
| Baseline T-score, SD | Follow-up T-score, SD | Baseline Z-score, SD | Follow-up Z-score, SD |
---|---|---|---|---|---|---|---|
Femoral neck | Total | 0.78 ± 0.13 | 0.77 ± 0.13*** | –0.9 ± 1.0 | –1.0 ± 1.0*** | –0.1 ± 1.0 | –0.1 ± 0.9 |
Men | 0.80 ± 0.13 | 0.79 ± 0.12* | –0.9 ± 0.9 | –1.0 ± 0.9 | –0.2 ± 0.9 | –0.2 ± 0.9 | |
Women | 0.76 ± 0.13 | 0.73 ± 0.13*** | –0.8 ± 1.1 | –1.0 ± 1.1*** | 0.0 ± 1.0 | 0.0 ± 1.0 | |
Total hip | Total | 0.94 ± 0.14 | 0.94 ± 0.14* | –0.4 ± 0.9 | –0.4 ± 1.0 | 0.0 ± 0.9 | 0.2 ± 0.9*** |
Men | 0.98 ± 0.13 | 0.99 ± 0.13*** | –0.4 ± 0.9 | –0.3 ± 0.9*** | –0.1 ± 0.9 | 0.2 ± 0.9*** | |
Women | 0.89 ± 0.13 | 0.88 ± 0.13 | –0.4 ± 1.0 | –0.5 ± 1.1 | 0.1 ± 0.9 | 0.3 ± 1.0*** | |
Lumbar spine AP | Total | 1.03 ± 0.18 | 1.05 ± 0.19*** | –0.4 ± 1.5 | –0.2 ± 1.6*** | 0.2 ± 1.5 | 0.6 ± 1.6*** |
Men | 1.08 ± 0.17 | 1.11 ± 0.18*** | –0.1 ± 1.6 | 0.2 ± 1.6*** | 0.2 ± 1.7 | 0.7 ± 1.7*** | |
Women | 0.96 ± 0.16 | 0.97 ± 0.17 | –0.8 ± 1.4 | –0.7 ± 1.5 | 0.1 ± 1.4 | 0.5 ± 1.5*** | |
Lumbar spine lateral | Total | 0.72 ± 0.13 | 0.74 ± 0.14*** | NA | NA | NA | NA |
Men | 0.76 ± 0.12 | 0.79 ± 0.14*** | NA | NA | NA | NA | |
Women | 0.68 ± 0.13 | 0.69 ± 0.13 | –1.7 ± 1.5 | –1.6 ± 1.6 | –0.1 ± 1.4 | 0.4 ± 1.5*** | |
Lumbar spine vBMD | Total | 0.19 ± 0.03 | 0.19 ± 0.03 | NA | NA | NA | NA |
Men | 0.19 ± 0.03 | 0.19 ± 0.03* | NA | NA | NA | NA | |
Women | 0.19 ± 0.04 | 0.20 ± 0.04 | NA | NA | NA | NA | |
Total radius | Total | 0.60 ± 0.08 | 0.59 ± 0.08*** | –0.7 ± 1.1 | –0.8 ± 1.2*** | –0.0 ± 1.0 | 0.0 ± 1.1 |
Men | 0.65 ± 0.06 | 0.64 ± 0.06** | –0.7 ± 1.1 | –0.8 ± 1.1** | –0.2 ± 1.0 | –0.2 ± 1.1 | |
Women | 0.54 ± 0.06 | 0.53 ± 0.07*** | –0.6 ± 1.1 | –0.8 ± 1.3*** | 0.2 ± 0.9 | 0.3 ± 1.0 |
Predictors for changes in BMD
Femoral neck | Total hip | Spine AP | Spine lateral | Spine vBMD | Total radius | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Constant | 20.4 | 1.5 | –13.4 | –47.3 | –40.5 | 10.4 | ||||||
β |
p
| β |
p
| β |
p
| β |
p
| β |
p
| β |
p
| |
Baseline | ||||||||||||
BMD at same site, g/cm2
|
–8.24
|
0.036
| 0.98 | 0.67 | 0.80 | 0.80 | 0.81 | 0.89 | –16.3 | 0.42 | 2.89 | 0.60 |
Age, years |
–0.12
|
0.006
| –0.05 | 0.063 | –0.04 | 0.31 | –0.04 | 0.50 | –0.07 | 0.22 |
–0.11
|
< 0.001
|
Sex | –1.61 | 0.11 |
–1.68
|
0.007
| –2.06 | 0.051 | –1.70 | 0.27 | –1.47 | 0.25 | –0.47 | 0.58 |
Pack years |
0.13
|
0.004
|
0.08
|
0.003
| 0.09 | 0.054 | 0.12 | 0.086 | 0.09 | 0.12 | –0.04 | 0.16 |
mSASSS, score |
0.06
|
0.041
| 0.005 | 0.76 | –0.03 | 0.27 | –0.08 | 0.052 | –0.06 | 0.10 | 0.02 | 0.26 |
During follow-up | ||||||||||||
Time between DXA, months | –0.19 | 0.41 | –0.02 | 0.86 | 0.24 | 0.31 |
0.81
|
0.016
|
0.77
|
0.009
| –0.14 | 0.36 |
Δweight, kg | 0.03 | 0.72 |
0.24
|
< 0.001
|
0.37
|
< 0.001
|
0.49
|
< 0.001
|
0.51
|
< 0.001
| 0.08 | 0.18 |
NSAID-index, 0–100 | 0.02 | 0.064 | 0.01 | 0.097 | 0.01 | 0.42 | 0.01 | 0.56 | 0.00 | 0.89 | 0.01 | 0.26 |
Use of TNFi, 0–1 | –1.53 | 0.11 | 1.23 | 0.086 |
3.15
|
0.012
| 2.17 | 0.22 | 1.06 | 0.49 | –0.65 | 0.41 |
Use of bisphosphonate, 0–1 |
4.64
|
0.013
|
5.61
|
< 0.001
|
13.7
|
< 0.001
|
15.5
|
< 0.001
|
11.6
|
< 0.001
| 0.83 | 0.48 |
Mean CRP last 5 years, mg/L |
–0.15
|
0.046
| NA | NA | NA | NA | –0.09 | 0.072 | ||||
ΔESR, mm/h | NA |
–0.10
|
< 0.001
|
–0.12
|
0.004
|
–0.16
|
0.007
|
–0.13
|
0.012
| NA | ||
R
2
| 0.22 | 0.44 | 0.41 | 0.33 | 0.34 | 0.20 |
Measuring site | % change in BMD |
p value between groups | |
---|---|---|---|
No syndesmophytes (n = 59) | Syndesmophytes present (n = 27) | ||
Spine AP | 1.13 ± 5.4* | 6.44 ± 9.6** |
0.01
|
Spine lateral | 2.12 ± 8.0 | 6.04 ± 11.5* | 0.19 |
vBMD | 1.08 ± 7.6 | 4.15 ± 10.0 | 0.31 |
Total hip | –0.02 ± 3.6 | 2.84 ± 3.7** |
0.001
|
Femoral neck | –3.15 ± 5.2*** | –0.48 ± 5.0 |
0.04
|
Total radius | –0.35 ± 2.9 | –0.68 ± 3.1 | 0.80 |
Subgroup analyses of different medications
Constant | Femoral neck | Total hip | Spine AP | Spine lateral | Spine vBMD | Total radius | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
14.0 | 5.53 | –16.4 | –54.4 | –47.6 | 3.58 | |||||||
β |
p
| β |
p
| β |
p
| β |
p
| β |
p
| β |
p
| |
Baseline | ||||||||||||
BMD at same site, g/cm2
| 0.09 | 1.0 | 4.90 | 0.1 | 3.20 | 0.4 | –6.94 | 0.3 | –47.9 | 0.06 | 9.73 | 0.2 |
Age, years | –0.08 | 0.1 | –0.02 | 0.6 | 0.03 | 0.6 | 0.03 | 0.7 | –0.05 | 0.5 |
–0.11
|
0.005
|
Sex | –0.53 | 0.7 | –0.75 | 0.4 | –2.11 | 0.1 | –1.42 | 0.5 | –0.40 | 0.8 | 0.15 | 0.9 |
Pack years |
0.17
|
0.01
| 0.07 | 0.08 | 0.12 | 0.07 |
0.20
|
0.04
| 0.16 | 0.07 |
–0.09
|
0.03
|
mSASSS, score | 0.08 | 0.06 | 0.01 | 0.7 | –0.07 | 0.1 | –0.07 | 0.3 | –0.03 | 0.6 | 0.02 | 0.5 |
During follow-up | ||||||||||||
Time between DXA, months | –0.27 | 0.4 | –0.16 | 0.4 | 0.21 | 0.5 |
1.00
|
0.02
|
1.00
|
0.006
| –0.09 | 0.6 |
Δweight, kg | 0.05 | 0.7 |
0.25
|
0.001
|
0.38
|
0.001
|
0.60
|
0.001
|
0.61
|
0.001
| 0.04 | 0.5 |
NSAID-index, 0–100 | 0.01 | 0.3 | 0.01 | 0.4 | 0.03 | 0.08 | 0.03 | 0.2 | 0.021 | 0.3 | 0.01 | 0.2 |
Mean ESR last 5 years, mm/h |
–0.19
|
0.01
|
–0.11
|
0.02
| –0.09 | 0.3 |
–0.24
|
0.04
|
–0.21
|
0.04
| NA | |
Mean CRP last 5 years, mg/L | NA | NA | NA | NA | NA | –0.14 | 0.06 | |||||
R
2
| 0.21 | 0.32 | 0.27 | 0.28 | 0.34 | 0.29 |