Table 3.
Comparison of pQCT Cortical Bone Measurements of the Gambian and Cambridge Young Women at 50% Tibia Site
| Gambian (n = 38) |
Cambridge (n = 38) |
% Diffa | % Diff adjb | Significant predictors | |||
|---|---|---|---|---|---|---|---|
| Median | Interquartile range | Median | Interquartile range | ||||
| Tot CSA (mm2) | 409.3 | 381.0–444.0 | 407.0 | 383.5–457.0 | −1.8 | 8.7∗ | Wt∗∗, ht∗∗ |
| Cort BMC (mg/mm) | 298.6 | 266.5–326.2 | 316.4 | 297.5–352.4 | −7.6∗∗ | 0.9 | Wt∗∗, ht∗ |
| Cort CSA (mm2) | 247.1 | 224.3–272.8 | 274.3 | 261.8–304.0 | −12.6∗∗∗ | −4.1 | Wt∗∗ |
| Cort BMD (mg/cm3) | 1205 | 1189–1218 | 1146 | 1135–1159 | 4.9∗∗∗ | 5.0∗∗∗ | |
| PeriC (mm) | 71.7 | 69.2–74.7 | 71.5 | 69.4–75.8 | −0.9 | 4.4∗ | Ht∗∗, wt∗∗ |
| EndoC (mm) | 45.2 | 40.1–48.2 | 41.2 | 38.7–43.5 | 8.0∗∗ | 14.7∗∗∗ | Ht∗ |
| Mean Cort thk (mm) | 4.32 | 3.84–4.55 | 4.92 | 4.73–5.28 | −15.0∗∗∗ | −12.4∗∗ | Wt∗ |
| SSI (mm3) | 1660 | 1477–1857 | 1543 | 1438–1934 | 2.1 | 16.7∗∗ | Ht∗∗, wt∗∗ |
Significant predictors of group differences are shown (− indicates inverse relationship).
Significance of results indicated: ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001.
Abbr: Tot CSA, total cross-sectional area; Cort BMC, cortical bone mineral content; Cort CSA, cortical cross-sectional area; Cort BMD, cortical bone mineral density; PeriC, periosteal circumference; EndoC, endosteal circumference; Cort thk, cortical thickness; SSI, strength strain index; wt, weight; ht, height.
% Diff: percentage difference between groups calculated using linear regression. Positive differences indicate that Gambian values are greater.
% Diff adj: percentage difference between groups calculated after adjusting for weight, height, and age.