Table 2.
One-year change in DXA variables, HRpQCT bone parameters and bone turnover markers
| Baseline measures | P value | Change over 12 months | P value | P value adjusted for baseline age, sex, and race | |||
|---|---|---|---|---|---|---|---|
|
Surgical
(n = 30) |
Nonsurgical
(n = 34) |
Surgical
(n = 29) |
Non–Surgical
(n = 29) |
||||
| DXA variables | |||||||
| LS BMD Z-scores | 1.10 (0.50, 1.53) (n = 30) |
1.20 (0.55, 1.65) (n = 33) |
1.000 | –0.30 (–0.55, 0)**** (n = 29) |
0 (–0.25, 0.25) (n = 29) |
.015 | .027 |
| Total hip BMD Z-scores | 1.50 (0.75, 2.1) (n = 29) |
1.65 (0.78, 2.13) (n = 34) |
1.000 | –0.75 (–1.25, –0.40)**** (n = 28) |
–0.10 (–0.20, 0.10) (n = 29) |
<.0001 | <.0001 |
| FN BMD Z-scores | 1.40 (0.85, 1.90) (n = 29) |
1.60 (0.80, 2.35) (n = 34) |
.798 | –0.70 (–1.28, –0.30)**** (n = 28) |
0 (–0.40, 0.25) (n = 29) |
<.0001 | <.0001 |
| Whole body BMD Z-scores | -0.15 (-0.90, 0.43) (n = 30) |
-0.10 (-0.73, 0.80) (n = 34) |
.576 | 0 (–0.35, 0.50) (n = 29) |
0 (–0.40, 0.20) (n = 29) |
.906 | .878 |
| HRpQCT variables | |||||||
| Radius | |||||||
| Total vBMD (mgHA/cm3) | 345.3 ± 11.8 (n = 26) |
349.7 ± 11.3 (n = 31) |
.792 | –5.7 ± 3.0 (n = 20) |
2.7 ± 3.14 (n = 22) |
.076 | .083 |
| Cortical vBMD (mgHA/cm3) | 836.5 (796.8, 850.5) (n = 26) |
836.0 (809.3, 879.8) (n = 31) |
.537 | 15.6 (6.40, 28.7)*** (n = 20) |
6.20 (–6.50, 15.9)* (n = 22) |
.031 | .325 |
| Trabecular vBMD (mgHA/cm3) | 201.0 (171.9, 223.9) (n = 26) |
204.8 (169.2, 221.0) (n = 31) |
.904 | –7.00 (–17.58, –0.80)** (n = 20) |
0.70 (–2.20, 2.95) (n = 22) |
.002 | .001 |
| Failure load (N) | 4597 (4060, 5029) (n = 26) |
4510 (3952, 5423) (n = 31) |
.846 | –94.5 (–203.5, 105.3) (n = 20) |
3.5 (–185.0, 148.3) (n = 22) |
.458 | .575 |
| Tibia | |||||||
| Total vBMD (mgHA/cm3) | 342.7 (293.0, 373.9) (n = 23) |
356.6 (330.0, 381.8) (n = 34) |
.207 | 1.90 (–14.00, 5.70) (n = 21) |
4.10 (2.70, 7.45)*** (n = 25) |
.050 | .010 |
| Cortical vBMD (mgHA/cm3) | 869.2 (844.8, 881.6) (n = 23) |
867.7 (850.3, 898.0) (n = 34) |
.510 | 12.0 (3.4, 24.7)*** (n = 21) |
6.4 (4.1, 12.6)** (n = 25) |
.363 | .598 |
| Trabecular vBMD (mgHA/cm3) | 207.5 (197.0, 236.3) (n = 23) |
218.0 (197.5, 240.8) (n = 34) |
.542 | 2.3 (–15.6, 5.0) (n = 21) |
2.4 (–0.8, 3.7) (n = 25) |
.612 | .038 |
| Failure load (N) | 12912 (11798, 13782) (n = 23) |
12696 (11361, 14367) (n = 34) |
.770 | 135.0 (–544.5, 656.5) (n = 21) |
142.0 (–7.8, 452.8)* (n = 24) |
.420 | .220 |
| Bone markers | |||||||
| P1NP (ug/L) | 78.1 (64.2, 105.9) (n = 29) |
76.7 (61.2, 99.5) (n = 33) |
.905 | 9.8 (–9.9, 29.9) (n = 27) |
–14.1 (–27.9, 0.3)* (n = 28) |
.007 | .058 |
| CTX (ng/mL) | 0.49 (0.37, 0.70) (n = 28) |
0.42 (0.27, 0.79) (n = 34) |
.713 | 0.27 (0.10, 0.37)** (n = 27) |
–0.09 (–0.16, 0.02)* (n = 29) |
.0001 | .0001 |
Data are presented as mean ± standard error of the mean or median (interquartile range); significant P values are in bold.
Between-group differences in baseline measures and changes over 12 months were compared using the Student t-test for parametric data and the 2-sample Wilcoxon rank sum test for nonparametric data.
For between group comparisons at baseline: †P < .05 after adjusting for baseline age, sex and race (Black vs non-Black). Within-group changes over 12-months were assessed using paired t-test (for parametric data) and using Wilcoxon signed rank test (for non-parametric data):
*P < 0.05,
** P < 0.01;
*** P < 0.001, and
**** P < .0001 indicate a significant within-group change over 12 months.
Abbreviations: LS, lumbar spine; FN, femoral neck; vBMD, volumetric bone density; P1NP, N-terminal propeptide of type 1 procollagen; CTX, C-terminal cross-linking telopeptide.