Table 3.

HRpQCT and FEA data for the distal tibia (weight bearing bone) in Blacks, Asian Americans and Whites

Tibia	Black (n=10)	Asian (n=15)	White (n=35)	P	P*	P**
Size Parameters
Cortical Thickness (mm)	1.33 ± 0.07	1.29 ± 0.05	1.23 ± 0.04	0.4	0.3	0.6
Cortical Perimeter (mm)	99.8 ± 3.0	93.9 ± 2.4	101.1 ± 1.3	0.02b	0.5	0.4
Cortical Area (mm2)	131.9 ± 6.5	120.0 ± 4.6	123.5 ± 3.5	0.3	0.3	0.8
% Cortical Area	20.5 ± 1.4	21.1 ± 1.3	18.6 ± 0.7	0.2	0.3	0.6
Microarchitecture Parameters
Cortical Pore Volume (mm3) †	12.78 ± 2.59	11.80 ± 2.43	18.36 ± 1.94	0.02b	0.2	0.3
Cortical Porosity (%) †	1.3 ± 0.2	1.2 ± 0.2	1.8 ± 0.2	0.02b	0.1	0.2
Cortical Pore Diameter (mm) †	0.143 ± 0.004	0.151 ± 0.005	0.152 ± 0.003	0.08	0.2	0.3
Trabecular Thickness (mm) †	0.087± 0.003	0.088 ± 0.004	0.084 ± 0.002	0.6	0.7	0.8
Trabecular Number (mm−1) †	2.09 ± 0.10	1.79 ± 0.08	2.00 ± 0.03	0.005b	0.03c	0.06
Trabecular Separation (mm)†	0.40 ± 0.02	0.49 ± 0.04	0.42 ± 0.01	0.007b	0.09	0.06
Density Parameters
Cortical Density (g/mm3) †	896.1 ± 12.5	892.8 ± 11.5	874.9 ± 6.1	0.1	0.2	0.5
Trabecular Density (g/mm3) †	217.2 ± 5.3	185.3 ± 9.9	200.1 ± 5.3	0.05	0.03c	0.3
Total Density (g/mm3)	358.8 ± 12.8	337.2 ± 14.7	326.7 ± 8.8	0.2	0.06	0.4
Estimated Strength Parameters
Stiffness (kN/m)	243.1± 11.8	209.2 ± 9.9	228.1 ± 5.9	0.07	0.2	0.6
Failure load (kN)	12.2 ± 0.6	10.5 ± 0.5	11.4 ± 0.3	0.05	0.2	0.6
Apparent modulus	2958 ± 402	2860 ± 136	2657 ± 78	0.1	0.08	0.3

^aWhite vs. Black p<0.05,

^bWhite vs. Asian p<0.05,

^cBlack vs. Asian p<0.05;

^*Controlled for height;

^**Controlled for height, lean mass, menarchal age and 25(OH)D;

^†Kruskal Wallis test