Differences In Bone Properties Of Elite Trained Female Soldiers And Matched Female Basic Combat Trainees

Differences in Bone Properties of Elite Trained Female Soldiers and matched Female Basic Combat Trainees BACKGROUND: Female basic combat trainees with least versus most favorable distal tibial microarchitecture and density are at greater risk for bone stress injury. However, elite combat training courses are now open to women and whether bone properties in this growing population differ from basic combat trainees and can also be used as proxies for injury risk are undetermined. PURPOSE: To determine whole-body bone mineral content (BMC), density (BMD), and distal tibial microarchitecture of the few women completing elite combat training (FEW) with female basic combat trainees (BCT). METHODS: BMC, BMD, and distal tibial microarchitecture were measured in 11 FEW (mean ± SD; 29.0 ± 4.8 yr and 69.3 ± 8.8 kg) and 33 age- and body-mass matched female BCT (28.2 ± 2.9 yr and 69.5 ± 8.6 kg) using dual energy x-ray absorptiometry and high resolution peripheral quantitative computed tomography, respectively. RESULTS: FEW had greater BMC (p < .05) and similar whole-body BMD than BCT (Table). Distal tibial microarchitectural measures were mostly similar between FEW and BCT (all>.05), with the exception of Ct.Area and Ct.Th, which were greater for FEW than BCT (both>.05, Table). CONCLUSION: Whole-body BMC and distal tibial cortical area and thickness were greater in FEW than BCT; however, most bone properties were similar. Whether the observed differences in bone properties confer protection against injury cannot be determined by our analyses and should be re-evaluated in future studies. - FEW (n = 11) BCT (n = 33) P value DXA BMD (g/cm2) 1.24 ± 0.08 1.20 ± 0.13 0.35 BMC (kg) 2.75 ± 0.30 2.42 ± 0.32 <0.01 HR-pQCT Tt.Area (mm2) 1003 ± 115 975 ± 129 0.54 Tt.vBMD (mg/cm3) 269 ± 43 240 ± 45 0.08 Tb.vBMD (mg/cm3) 211 ± 34 186 ± 35 0.05 Tb.Th (mm) 0.250 ± 0.024 0.233 ± 0.026 0.09 Tb.N (mm-1) 1.65 ± 0.18 1.68 ± 0.19 0.67 Tb.Sp (mm) 0.557 ± 0.068 0.562 ± 0.081 0.85 Ct.Area (mm2) 99.0 ± 17.9 84.1 ± 17.6 0.03 Ct.Th (mm) 0.930 ± 0.215 0.782 ± 0.182 0.04 Table. Results are means ± SD. Tt.Area = total area; Tt.vBMD = total volumetric bone mineral density; Tb.vBMD = trabecular volumetric bone mineral density; Tb.Th = trabecular thickness; Tb.N = trabecular number; Tb.Sp = trabecular spacing; Ct.Area = cortical area; Ct.Th = cortical thickness. Supported by USAMRDC; views expressed are not official U.S. Army, DoD or Government policy.