TABLE II.

Comparison of cortical bone thickness (mm) and density (mg/cm³) measures between male and female cohort members from the Iowa Bone Development Study.

	Males (N = 46)	Females (N = 51)	Effect sizea
ROI	Mean ± SD	Mean ± SD	Unadjusted	Adjusted	p valueb
Thickness (mm)
T8−10	1.53 ± 0.23	1.33 ± 0.18	0.97	0.73	0.02
T10−12	1.81 ± 0.24	1.58 ± 0.20	1.05	0.80	<0.01
T12−14	2.06 ± 0.26	1.80 ± 0.19	1.14	0.83	<0.01
T14−16	2.28 ± 0.27	2.02 ± 0.20	1.12	0.74	0.01
Alateral	1.77 ± 0.25	1.57 ± 0.29	0.72	0.56	0.06
Aanterior	2.15 ± 0.30	1.82 ± 0.24	1.24	0.92	<0.01
Amedial	1.94 ± 0.33	1.67 ± 0.25	0.94	0.65	0.03
Aposterior	1.81 ± 0.32	1.65 ± 0.25	0.54	0.36	0.23
Bone mineral density (mg/cm3)
T8−10	1850.23 ± 26.11	1879.67 ± 29.86	−1.05	−1.26	<0.0001
T10−12	1882.49 ± 17.74	1909.13 ± 19.53	−1.42	−1.35	<0.0001
T12−14	1898.28 ± 14.04	1922.44 ± 16.14	−1.59	−1.30	<0.0001
T14−16	1907.18 ± 12.89	1929.64 ± 13.96	−1.67	−1.32	<0.0001
Alateral	1883.47 ± 22.41	1912.14 ± 23.21	−1.26	−1.29	<0.0001
Aanterior	1890.26 ± 18.67	1909.94 ± 19.80	−1.02	−0.88	<0.01
Amedial	1887.58 ± 18.00	1913.21 ± 20.63	−1.32	−1.25	<0.0001
Aposterior	1876.86 ± 18.05	1905.59 ± 20.44	−1.48	−1.35	<0.0001

^aEffect size was calculated as the difference (males − females) between least-squares means for male and female IBDS cohort members standardized by $\sqrt{\text{MSE}}$, where MSE is the mean square error from the linear regression models with (adjusted) and without (unadjusted) adjustment for height and weight.

^bp-value from multivariable linear regression models with adjustment for height and weight differences.