Table 2.

Trabecular and cortical bone architecture and muscle mass following 21 days of Mars-analog loading in female mice

	Baseline	Age	Jacket	Mars
n	7–8	19–20	8	8–9
Trabecular bone architecture (distal femur)
Bone volume fraction, %	23.51 ± 3.03	18.97 ± 2.60c	18.06 ± 1.60	14.34 ± 3.18a,b
Trabecular thickness, μm	54.97 ± 0.00	54.24 ± 2.30	53.26 ± 2.82	47.65 ± 1.85a,b
Trabecular number, mm−1	5.24 ± 0.29	4.47 ± 0.30c	4.47 ± 0.18	4.37 ± 0.29
Trabecular spacing, μm	182.84 ± 12.34	217.84 ± 18.20c	216.65 ± 9.61	222.46 ± 15.06
Connectivity density, mm−3	207.12 ± 23.89	137.35 ± 19.16c	145.84 ± 18.73	124.29 ± 26.29b
Structural model index	1.31 ± 0.30	1.62 ± 0.27c	1.79 ± 0.22	2.14 ± 0.40a,b
Cortical bone architecture (distal femur)e
Cortical thickness, μm	166.57 ± 9.66	167.10 ± 8.06	158.60 ± 7.47d	134.00 ± 6.46a,b
Cortical bone architecture (femoral midshaft)
Cross-sectional area, mm2	1.55 ± 0.09	1.56 ± 0.09	1.55 ± 0.09	1.46 ± 0.10a
Cortical bone area, mm2	0.87 ± 0.08	0.90 ± 0.05	0.87 ± 0.05	0.79 ± 0.05a,b
Minimum moment of inertia, mm4	0.10 ± 0.01	0.11 ± 0.01	0.11 ± 0.01	0.09 ± 0.01a,b
Medullary area, mm2	0.68 ± 0.08	0.66 ± 0.08	0.68 ± 0.07	0.68 ± 0.07
Cortical thickness, μm	223.75 ± 16.46	238.30 ± 13.47c	230.75 ± 5.31	212.44 ± 8.92a,b
Gastrocnemius muscle wet massf
Average mass, mg	107.88 ± 7.26	118.73 ± 5.58c	113.50 ± 9.19	90.88 ± 9.38a,b
Average mass/body mass, %	0.55 ± 0.02	0.55 ± 0.06	0.51 ± 0.01	0.48 ± 0.04a

Values are means ± SD; n, no. of mice (^en = 10 for Age; ^fn = 8 for Baseline, n = 13 for Age, n = 2 for Jacket, n = 4 for Mars).

^aMars significantly different than Age,

^bMars significantly different than Jacket,

^cAge significantly different than Baseline, and

^dJacket significantly different from Age: P < 0.05.