Table 3.
Multivariable linear regression analysis assessing AS as an independent predictor of BMD, and bone microarchitecture
| HRpQCT | Radius | Tibia | ||||||
|---|---|---|---|---|---|---|---|---|
| βa | 95 % CI | p value | Adj. R 2 | βa | 95 % CI | p value | Adj. R 2 | |
| Trabecular vBMD | −15.1 | −33.3 to –3.2 | 0.105 | 0.184 | −17.2 | −35.3 to –1.5 | 0.071 | 0.094 |
| Cortical vBMD | −34.3 | −62.8 to –7.9 | 0.011 | 0.160 | −28.15 | −55.1 to –5.4 | 0.018 | 0.096 |
| Total vBMD | −41.6 | −71.0 to –12.1 | 0.006 | 0.087 | −28.13 | −51.7 to 4.5 | 0.020 | 0.256 |
| Trabecular number | –0.088 | –0.244 to –0.068 | 0.268 | 0.070 | –0.065 | −0.343 to 0.113 | 0.471 | 0.063 |
| Trabecular thickness | –0.004 | –0.008 to 0.001 | 0.087 | 0.217 | –0.004 | –0.010 to 0.003 | 0.260 | 0.001 |
| Trabecular separation | 0.052 | 0.011–0.115 | 0.105 | 0.072 | 0.060 | –0.017 to 0.137 | 0.128 | 0.063 |
| BV/TV (%) | –0.013 | –0.028 to –0.003 | 0.106 | 0.184 | –0.014 | –0.030 to –0.001 | 0.070 | 0.094 |
| Cortical thickness | –0.101 | –0.163 to –0.039 | 0.002 | 0.202 | –0.060 | –0.116 to 0.004 | 0.035 | 0.381 |
| Cortical porosity | 0.006 | 0.001–0.010 | 0.016 | 0.326 | 0.013 | 0.002–0.023 | 0.016 | 0.323 |
| Stiffness | –0.226 | –0.384 to –0.069 | 0.005 | 0.055 | –0.160 | –0.333 to 0.013 | 0.069 | 0.081 |
| Stress | −5.7 | −9.61 to –1.7 | 0.005 | 0.055 | −4.0 | −8.3 to 0.24 | 0.064 | 0.082 |
aBeta coefficient represents the difference between patients with AS (n = 53) and subjects without AS (n = 85), and subjects without AS are the reference category. The model was adjusted for differences in age and sex
Adj. adjusted, AS ankylosing spondylitis, BMD bone mineral density, BV/TV bone volume/trabecular volume, CI confidence interval, HRpQCT high-resolution peripheral quantitative computerized tomography, vBMD volumetric bone mineral density