Table 1.

The independent and combined effects of sex and age on femur in mice housed at 22°C.

Variable	Baseline		Study completion		Sex	Age	Sex × age
	8 weeks old		16–18 weeks old
	Female (8 week)	Male (8 week)	Female (18 week)	Male (16 week)	P value	P value	P value
Total femur
Length (mm)	14.5 ± 0.1	14.8 ± 0.1	14.9 ± 0.1	15.1 ± 0.1	0.003	0.001	NS
Bone volume (mm3)	15.7 ± 0.3	19.1 ± 0.3a	16.6 ± 0.5	18.5 ± 0.3a	–	–	0.049
Femur diaphysis
Cortical thickness (µm)	167 ± 2	176 ± 2a	192 ± 3b	189 ± 1b	–	–	0.028
Distal femur metaphysis
Cancellous bone volume fraction (%)	9.8 ± 0.6	15.8 ± 0.7	3.5 ± 0.4	9.7 ± 0.6	0.0001	0.0001	NS
Trabecular number (1/mm)	5.4 ± 0.1	6.3 ± 0.1a	3.6 ± 0.1b	4.9 ± 0.1a,b	–	–	0.045
Trabecular thickness (µm)	38 ± 1	42 ± 1	38 ± 1	43 ± 1	0.02	NS	NS

^aDifferent from females within same age, P < 0.05. ^bDifferent from baseline within same sex, P < 0.05.