HR-pQCT bone variables at the dominant and non-dominant distal tibia and radius, before and after spaceflight
| Dominant limb | Non-dominant limb | |||
| Pre-flight | Post-flight | Pre-flight | Post-flight | |
| Tibia | ||||
| F.Load (n) | 10 643.5 (9302.5, 12 483.5) | 10 163.4 (8943.5, 12 013.0)** | 10 485.0 (9743.3, 12 261.0) | 10 209.0 (9077.3, 11 473.0)** |
| Tt.vBMD (mg/cm3) | 320.1 (296.5, 357.1) | 317.2 (286.0, 350.5)** | 324.0 (314.5, 364.1) | 317.7 (303.4, 353.0)** |
| Tb.vBMD (mg/cm3) | 189.9 (164.7, 213.7) | 188.5 (163.3, 207.5)** | 183.3 (178.4, 208.4) | 181.7 (175.2, 202.6)** |
| Tb.BV/TV (%) | 27.70 (24.65, 30.52) | 27.59 (24.34, 29.90)** | 26.76 (25.93, 29.94) | 26.55 (25.45, 29.26)** |
| Tb.Th (mm) | 0.269 (0.258, 0.291) | 0.266 (0.254, 0.288)** | 0.261 (0.258, 0.278) | 0.259 (0.253, 0.278)* |
| Tb.N (1/mm) | 1.39 (1.22, 1.47) | 1.37 (1.22, 1.50) | 1.38 (1.21, 1.54) | 1.39 (1.39, 1.39)* |
| Tb.Sp (mm) | 0.68 (0.63, 0.76) | 0.68 (0.62, 0.78) | 0.66 (0.61, 0.76) | 0.66 (0.61, 0.73) |
| Ct.vBMD (mg/cm3) | 946.1 (886.1, 954.3) | 912.6 (862.1, 941.1)** | 924.3 (869.6, 950.6) | 913.1 (855.2, 933.3)**\ |
| Ct.Th (mm) | 1.55 (1.44, 1.69) | 1.54 (1.40, 1.67) | 1.60 (1.48, 1.67) | 1.61 (1.54, 1.64) |
| Ct.Po (%) | 2.32 (1.78, 2.93) | 2.61 (1.88, 2.98) | 2.67 (1.86, 3.66) | 2.87 (2.20, 3.45) |
| Radius | ||||
| F.Load (n) | 4067.3 (3692.4, 4796.0) | 4174.2 (3601.9, 4794.4) | 4082.5 (3622.2, 4746.9) | 4208.1 (3595.6, 4692.2) |
| Tt.vBMD (mg/cm3) | 327.0 (305.6, 362.3) | 327.1 (303.4, 363.7) | 334.1 (312.3, 360.5) | 331.3 (315.6, 361.6) |
| Tb.vBMD (mg/cm3) | 183.2 (161.3, 191.1) | 184.4 (161.9, 189.3) | 177.7 (156.9, 192.5) | 181.7 (175.2, 202.6) |
| Tb.BV/TV (%) | 26.28 (23.14, 27.48) | 26.24 (23.05, 27.54) | 26.19 (22.34, 27.59) | 26.55 (25.45, 29.26) |
| Tb.Th (mm) | 0.237 (0.232, 0.249) | 0.238 (0.231, 0.249) | 0.242 (0.228, 0.250) | 0.241 (0.224, 0.248)* |
| Tb.N (1/mm) | 1.51 (1.41, 1.59) | 1.52 (1.40, 1.61) | 1.49 (1.39, 1.56) | 1.46 (1.34, 1.59) |
| Tb.Sp (mm) | 0.60 (0.57, 0.67) | 0.60 (0.57, 0.66) | 0.66 (0.61, 0.76) | 0.62 (0.58, 0.68) |
| Ct.vBMD (mg/cm3) | 915.0 (887.6, 958.1) | 910.7 (891.5, 955.4) | 911.2 (893.9, 950.5) | 919.0 (893.7, 955.9) |
| Ct.Th (mm) | 1.12 (0.97, 1.18) | 1.13 (0.96, 1.17) | 1.13 (1.00, 1.18) | 1.14 (0.99, 1.18) |
| Ct.Po (%) | 0.62 (0.48, 0.82) | 0.61 (0.47, 0.87) | 0.71 (0.39, 0.89) | 0.76 (0.59, 0.86) |
Data are median (IQR). n=16 for dominant tibia, and both radii; n=17 for non-dominant tibia.
*p Value <0.05; **p<0.01 for difference post-flight versus pre-flight based on Wilcoxon signed rank test. Pairwise percent change data presented in text.
Ct.Po, cortical porosity; Ct.Th, cortical thickness; Ct.vBMD, cortical vBMD; F.Load, failure load; HR-pQCT, high-resolution peripheral quantitative CT; Tb.BV/TV, trabecular bone volume fraction; Tb.N, trabecular number; Tb.Sp, trabecular separation; Tb.Th, trabecular thickness; Tb.vBMD, trabecular vBMD; Tt.vBMD, total volumetric bone mineral density.