Table 4.
Compositional behavior model for bone mass variables for the proportion of time per day spent in ST, SB, LPA, and MVPA.
| Bone Variables. | Model p-Value | γST | p-Value | γSB | p-Value | γLPA | p-Value | γMVPA | p-Value |
|---|---|---|---|---|---|---|---|---|---|
| Tt.BMC 4% | 0.099 | −0.417 | 0.111 | 0.399 | 0.134 | −0.257 | 0.332 | 0.272 | 0.069 |
| Tt.BMD 4% | 0.689 | −8.698 | 0.727 | 9.813 | 0.553 | −16.114 | 0.387 | 14.998 | 0.300 |
| Tt.Area 4% | 0.099 | −0.414 | 0.110 | 0.399 | 0.134 | 0.257 | 0.332 | 0.272 | 0.069 |
| Tb.BMD 4% | 0.689 | −8.698 | 0.727 | 9.813 | 0.703 | −16.114 | 0.553 | 14.998 | 0.300 |
| Tt.BMC 38% | 0.105 | −0.288 | 0.133 | 0.383 | 0.052 | −0.313 | 0.132 | 0.218 | 0.041 |
| Tt.BMD 38% | 0.883 | 0.012 | 0.965 | −0.146 | 0.585 | 0.195 | 0.488 | −0.061 | 0.675 |
| Tt.Area 38% | 0.264 | 21.487 | 0.297 | −12.774 | 0.530 | 6.254 | 0.770 | −14.967 | 0.180 |
| Crt.BMD 38% | 0.773 | 9.937 | 0.785 | 8.932 | 0.793 | −36.899 | 0.328 | 18.029 | 0.332 |
| Ct.Th | 0.012 | −0.533 | 0.163 | 0.446 | 0.245 | −0.502 | 0.190 | 0.590 | 0.005 |
| SSIp | 0.477 | −150.65 | 0.120 | 121.51 | 0.202 | 24.466 | 0.801 | 4.677 | 0.926 |
| Fracture Load X | 0.700 | −371.13 | 0.420 | 176.36 | 0.702 | 70.65 | 0.886 | 124.12 | 0.627 |
All models are adjusted for sex, age, object length, muscle area, alcohol intake, smoking, serum vitamin D, and calcium by backward elimination (with predictor retained if p < 0.2). Statistically significant associations (p < 0.05) are highlighted in bold. ST: Sleep time, SB: Sedentary behavior; LPA: Light physical activity; MVPA: Moderate-to-vigorous physical activity; Tt.BMC: Total bone mineral content; Tt.BMD: Total bone mineral density; Tb.BMD: Trabecular bone mineral density; Tt.Ar: Total bone mineral area; Ct.BMD: Cortical bone mineral density; Ct.Th: Cortical bone thickness; SSIp: Polar stress strain index.