Table 1.
Demographical, clinical characteristics and bone assessment on CT of the 73 AS patients according to spine structural involvement (mSASSS or vertebra ankylosis).
| All patients n = 73 |
mSASSS + n = 60 |
mSASSS - n = 13 |
p | mSASSS + | |||
|---|---|---|---|---|---|---|---|
| Bone bridge + | Bone bridge - | p | |||||
| n = 37 | n = 23 | ||||||
| Demographic and clinic | |||||||
| Age (n = 73) | 60.3 (60) | 62 (61) | 52.7 (57) | 0.493 | 62 (57.5–73) | 59 (53–67) | 0.88 |
| Men (n = 73) | 65 (89) | 53 (88.3) | 12 (92.3) | 0.677 | 34 (91.9) | 19 (82.6) | 0.276 |
| Smoker (n = 48) | 31 (42.5) | 25 (41.7) | 6 (46.2) | 0.5 | 17 (45.9) | 8 (34.8) | 0.931 |
| Alcool (n = 28) | 4 (5.48) | 4 (6.7) | 0 (0) | 0.678 | 4 (10.8) | 0 (0) | 0.160 |
| AS characteristics | |||||||
| Disease duration (n = 71) | 24 (12–34) | 25 (13–35) | 15.5 (12–25.25) | 0.076 | 27 (13.75–35.75) | 24 (11–35) | 0.529 |
| BASFI (n = 58) | 43.5 (23.7) | 44.5 (22.2) | 41.2 (30.8) | 0.598 | 46.7 (22.2) | 42 (22.4) | 0.319 |
| BASDAI (n = 62) | 7.2 (10.5) | 7.1 (10.5) | 8.4 (11.3) | 1.0 | 7.2 (12.7) | 6.9 (7.3) | 0.236 |
| ASDAS (n = 21) | 3.4 (1.2) | 3.4 (0.9) | 3 (2.6) | 0.763 | 3.7 (1) | 2.81 (0.6) | 0.035 |
| HLA B27 (n = 69) | 46 (63) | 39 (65) | 7 (53.8) | 0.276 | 26 (70.3) | 13 (56.5) | 0.075 |
| Biological inflammation CRP (n = 69) | 31 (42.5) | 28 (46.7) | 3 (23.1) | 0.079 | 18 (48.6) | 10 (43.5) | 0.415 |
| mSASSS on radiographs (n = 73) | 20.7 (21.2) | 25.1 (20.8) | 0 (0) | 0.0001 | 37.2 (17.8) | 5.9 (4.2) | 0.0001 |
| Treatments | |||||||
| Corticosteroids (n = 49) | 7 (9.6) | 5 (8.3) | 2 (15.4) | 0.243 | 3 (8.1) | 2 (8.7) | 0.926 |
| NSAIDs (n = 51) | 49 (67.1) | 44 (73.3) | 5 (38.5) | 0.634 | 30 (81.1) | 14 (60.9) | 0.048 |
| Proton Pomp Inhibitor (n = 15) | 15 (20.5) | 14 (23.3) | 1 (7.7) | / | 9 (24.3) | 5 (21.7) | / |
| TNF inhibitor (n = 43) | 43 (58.9) | 36 (60) | 7 (53.8) | / | 23 (62.2) | 13 (56.5) | / |
| Vitamin D and/or calcium (n = 73) | 18 (24.6) | 14 (23.3) | 4 (30.8) | 0.573 | 9 (24.3) | 5 (21.7) | 0.818 |
| Specific treatment for osteoporosis (n = 72) | 12 (16.4) | 9 (15) | 3 (23.1) | 0.493 | 8 (21.6) | 1 (4.3) | 0.063 |
| SBAC-L1 | |||||||
| Mean (SD) in HU | 141.1 (45) | 138.1 (44.8) | 154.8 (44.9) | 0.239 | 123.96 (41.1) | 160.4 (41.9) | 0.002 |
| Fracture threshold (145 HU) | 42 (57.5) | 36 (60) | 6 (46.2) | 0.325 | 27 (73) | 9 (39.1) | 0.006 |
| VF | |||||||
| Number of patients | 9 (12.3) | 8 (13.3) | 1 (7.7) | 0.575 | 5 (13.5) | 3 (13) | 0.958 |
| Number of fractures | 13 | 12 | 1 | 0.582 | 8 | 4 | 0.435 |
all data in bold are statiscally significant data (p<0.05)
AS, ankylosing spondylitis; ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath ankylosing spondylitis disease activity index; BASFI, Bath ankylosing spondylitis functional index; CRP, C-reactive protein; HU, Hounsfield unit; mSASSS, modified Stoke Ankylosing Spondylitis Spinal Score; NSAIDs, Non-steroidal anti-inflammatory drugs; SBAC-L1, scanographic bone attenuation coefficient of the first lumbar vertebra; SD, standard deviation; TNF, tumour necrosis factor; VF, vertebral fracture.
Age in mSASSS + group and disease duration are in median (IQR), whereas age in general population, BASDAI, BASFI, ASDAS are in mean (± SD). In the comparisons, the Student’s t-test or the Mann–Whitney U test were used. For qualitative variables, the chi-square test with, if necessary, the exact calculation of Fisher was used. The risk α was established as 0.05.
mSASSS + was defined by a mSASSS ≥ 2, with the presence of at least one syndesmophyte.