Table 4.
Regression modeling to determine independent predictors of bone microarchitecture parameters at the distal tibia
| Covariates | Parameter estimate | F ratio | P value | R2 | Cumulative R2 |
|---|---|---|---|---|---|
| Distal tibia | |||||
| Trabecular area (mm2) | |||||
| Intercept | 584.70 | ||||
| Lean mass (kg) | 10.29 | 40.5 | <0.0001 | 0.46 | |
| Age at menarche (yr) | 21.41 | 14.2 | 0.0005 | 0.10 | |
| Bone age (yr) | −43.91 | 10.2 | 0.003 | 0.08 | 0.64 |
| Trabecular density (mg HA/cm3) | |||||
| Intercept | 0.92 | ||||
| Age at menarche (yr) | −6.29 | 9.3 | 0.004 | 0.15 | |
| Bone age (yr) | 15.97 | 11.4 | 0.002 | 0.13 | |
| Subject grouping (AA vs. NAC and EA) | −4.04 | 2.9 | 0.07 | 0.08 | |
| Subject grouping (EA vs. NAC) | 9.45 | 4.5 | 0.04 | 0.37 | |
| Tb.N (1/mm) | |||||
| Intercept | 3.25 | ||||
| Subject grouping (AA vs. NAC and EA) | −0.12 | 11.5 | 0.001 | 0.18 | |
| Bone age (yr) | −0.10 | 5.7 | 0.02 | 0.08 | |
| Lean mass (kg) | 0.009 | 3.6 | 0.07 | 0.06 | 0.32 |
| Tb.Th (mm) | |||||
| Intercept | −0.09 | ||||
| Bone age (yr) | 0.01 | 20.4 | <0.0001 | 0.30 | 0.30 |
| Tb.Sp (mm) | |||||
| Intercept | 0.16 | ||||
| Subject grouping (AA vs. NAC and EA) | 0.03 | 8.9 | 0.005 | 0.24 | |
| Lean mass (kg) | −0.003 | 5.3 | 0.03 | 0.05 | |
| Age at menarche (yr) | 0.009 | 3.6 | 0.07 | 0.05 | |
| Bone age (yr) | 0.02 | 2.9 | 0.09 | 0.04 | 0.38 |
| Cortical area (mm2) | |||||
| Intercept | 109.75 | ||||
| Lean mass (kg) | 1.60 | 21.0 | <0.0001 | 0.19 | |
| Age at menarche (yr) | −4.39 | 12.8 | 0.0008 | 0.18 | 0.37 |
| Cortical density (mg HA/cm3) | |||||
| Intercept | 768.47 | ||||
| Age at menarche (yr) | −6.76 | 9.0 | 0.004 | 0.18 | |
| Bone age (yr) | 14.39 | 6.9 | 0.01 | 0.10 | |
| Lean mass (kg) | −1.15 | 3.2 | 0.08 | 0.05 | 0.33 |
| Cortical thickness (mm) | |||||
| Intercept | 0.86 | ||||
| Age at menarche (yr) | −0.057 | 15.9 | 0.0002 | 0.23 | |
| Bone age (yr) | 0.064 | 3.2 | 0.08 | 0.05 | 0.28 |
| Cortical perimeter (mm) | |||||
| Intercept | 93.25 | ||||
| Lean mass (kg) | 0.94 | 64.83 | <0.0001 | 0.57 | |
| Age at menarche (yr) | 1.30 | 10.1 | 0.003 | 0.06 | |
| Bone age (yr) | −2.92 | 8.6 | 0.005 | 0.06 | 0.69 |
| Total area (mm2) | |||||
| Intercept | 667.56 | ||||
| Lean mass (kg) | 11.78 | 61.4 | <0.0001 | 0.55 | |
| Bone age (yr) | −42.26 | 10.9 | 0.002 | 0.07 | |
| Age at menarche (yr) | 17.26 | 10.6 | 0.002 | 0.07 | 0.69 |
| Total density (mg HA/cm3) | |||||
| Intercept | 97.07 | ||||
| Age at menarche (yr) | −15.22 | 23.3 | <0.0001 | 0.28 | |
| Bone age (yr) | 24.65 | 9.6 | 0.003 | 0.12 | 0.40 |
| Distal radius | |||||
| Trabecular area (mm2) | |||||
| Intercept | 342.96 | ||||
| Lean mass (kg) | 3.44 | 17.5 | 0.0001 | 0.29 | |
| Bone age (yr) | −20.27 | 8.4 | 0.006 | 0.10 | |
| Age at menarche (yr) | 5.87 | 4.1 | 0.048 | 0.05 | 0.44 |
| Trabecular density (mg HA/cm3) | |||||
| Intercept | 288.85 | ||||
| Age at menarche (yr) | −8.65 | 17.2 | 0.0001 | 0.27 | 0.27 |
| Tb.N (1/mm) | |||||
| Intercept | 2.41 | ||||
| Age at menarche (yr) | −0.03 | 3.4 | 0.07 | 0.07 | 0.07 |
| Tb.Th (mm) | |||||
| Intercept | 0.027 | ||||
| Age at menarche (yr) | −0.0027 | 12.1 | 0.001 | 0.18 | |
| Bone age (yr) | 0.0046 | 5.4 | 0.02 | 0.08 | 0.26 |
| Tb.Sp (mm) | |||||
| Intercept | 0.29 | ||||
| Age at menarche (yr) | 0.011 | 6.7 | 0.01 | 0.12 | 0.12 |
| Cortical area (mm2) | |||||
| Intercept | 46.26 | ||||
| Age at menarche (yr) | −2.21 | 7.7 | 0.008 | 0.13 | |
| Lean mass (kg) | 0.81 | 11.9 | 0.001 | 0.10 | |
| Subject grouping (AA and EA vs. NAC) | −4.71 | 7.1 | 0.01 | 0.11 | 0.34 |
| Cortical density (mg HA/cm3) | |||||
| Intercept | 449.26 | ||||
| Age at menarche (yr) | −13.34 | 15.1 | 0.0003 | 0.18 | |
| Bone age (yr) | 31.58 | 13.3 | 0.0007 | 0.18 | 0.36 |
| Cortical thickness (mm) | |||||
| Intercept | 1.33 | ||||
| Age at menarche (yr) | −0.05 | 14.9 | 0.0004 | 0.22 | |
| Bone age (yr) | 0.05 | 3.3 | 0.07 | 0.05 | 0.27 |
| Cortical perimeter (mm) | |||||
| Intercept | 72.44 | ||||
| Lean mass (kg) | 0.61 | 38.0 | <0.0001 | 0.43 | |
| Bone age (yr) | −1.76 | 4.0 | 0.05 | 0.04 | 0.47 |
| Total area (mm2) | |||||
| Intercept | 399.3 | ||||
| Lean mass (kg) | 4.35 | 31.5 | <0.0001 | 0.36 | |
| Bone age (yr) | −18.21 | 7.1 | 0.01 | 0.09 | 0.45 |
| Total density (mg HA/cm3) | |||||
| Intercept | 144.91 | ||||
| Age at menarche (yr) | −16.15 | 21.9 | <0.0001 | 0.34 | |
| Bone age (yr) | 22.03 | 7.2 | 0.01 | 0.09 | |
| Subject grouping (AA and EA vs. NAC) | −12.24 | 2.9 | 0.09 | 0.04 | 0.47 |
HA, Hydroxyapatite.