Table 3.

Association Between Age and Sex and the pQCT Bone Parameters Over Time

	pQCT bone parameters
	Medullary bone area 38% (mm2)	p	Cortical bone area 38 (mm2)	p	Cross-sectional moment of inertia 38% (g/cm)	p
Model 1
Intercept	298.99		294.54		1322.01
Age*	1.02 ± 0.07	<0.0001	−0.60 ± 0.11	<0.0001	−1.81 ± 0.68	0.008
Time†	0.60 ± 1.03	0.56	−7.55 ± 2.27	0.001	−25.46 ± 13.24	0.05
Age × time	0.038 ± 0.02	0.02	0.11 ± 0.03	0.0007	0.33 ± 0.19	0.08
Sex‡	36.35 ± 6.52	<0.0001	48.69 ± 13.08	0.0002	804.17 ± 141.25	<0.0001
Age × sex	−0.53 ± 0.10	<0.0001	0.81 ± 0.19	<0.0001	1.22 ± 2.33	0.59
Sex × time	2.73 ± 1.39	0.04	8.14 ± 3.62	0.02	−7.72 ± 32.97	0.82
Age × time × sex	−0.05 ± 0.02	0.02	−0.14 ± 0.05	0.006	−0.08 ± 0.52	0.87
Model 2
Intercept	11.1
Age	1.02 ± 0.07	<0.0001
Time	−0.38 ± 2.48	0.88
Age × time	−0.001 ± 0.05	0.98
Age × time × time	0.01 ± 0.008	0.39
Time × time	0.13 ± 0.42	0.76
Sex	40.03 ± 6.73	<0.0001
Sex × age	0.58 ± 0.10	<0.0001
Sex × time	−7.65 ± 3.51	0.03
Sex × age × time	0.08 ± 0.06	0.19
Sex × time × time	1.71 ± 0.62	0.006
Sex × age × time × time	−0.02 ± 0.01	0.04

* Age = age at enrollment.

^† Time = years since follow-up (range, 0–6 yr).

^‡ Sex = men: 1, women: 0.