Table 1.
Effects of energy restriction (ER) and energy restriction + PTH on tibial length, cancellous bone in the proximal tibial metaphysis, and cortical bone in the tibial diaphysis of 6-month-old male rats.
| Endpoint | Baseline | Control | ER | ER + PTH | ANOVA P< |
|---|---|---|---|---|---|
| Tibia length (cm) | 4.4 ± 0.0 | 4.3 ± 0.1 | 4.4 ± 0.0 | 4.4 ± 0.1 | NS |
| Proximal tibia (cancellous bone) | |||||
| Bone area/tissue area (%) | 25.0 ± 1.0 | 23.8 ± 2.7 | 21.5 ± 2.0 | 29.7 ± 1.3a*,c | 0.048 |
| Trabecular number (mm−1) | 3.3 ± 0.1 | 3.1 ± 0.2 | 2.9 ± 0.2 | 3.5 ± 0.2 | 0.050 |
| Trabecular thickness (μm) | 77 ± 3 | 75 ± 4 | 74 ± 4 | 85 ± 3 | NS |
| Trabecular separation (μm) | 234 ± 11 | 258 ± 30 | 287 ± 25 | 204 ± 13 | 0.093 |
| Tibial diaphysis (cortical bone) | |||||
| Cross-sectional area (mm2) | 3.54 ± 0.15 | 3.46 ± 0.12 | 3.48 ± 0.10 | 3.35 ± 0.11 | NS |
| Cortical area (mm2) | 2.56 ± 0.14 | 2.36 ± 0.12 | 2.51 ± 0.08 | 2.37 ± 0.13 | NS |
| Marrow area (mm2) | 0.91 ± 0.13 | 1.10 ± 0.07 | 0.97 ± 0.07 | 0.99 ± 0.06 | NS |
Values are mean ± SE
a
Different from Baseline, P<0.05;
a*
P<0.1
c
Different from ER, P<0.05