Effect of type 1 and type 2 diabetes on human femoral trabecular bone composition, microarchitecture, and mechanical...

Both type 1 diabetes (T1D) and type 2 diabetes (T2D) increase hip fracture risk beyond what bone mineral density (BMD) explains, potentially due to changes in bone material from advanced glycation end-products (AGEs) and altered matrix composition. However, there are limited data regarding the impact of diabetes on human trabecular bone composition and mechanical behavior. We assessed trabecular bone material behavior using cadaveric femoral specimens from older adults with long-duration T1D (≥50 years; n = 24), T2D (n = 21), and non-diabetic controls (n = 21). Femoral head trabecular bone was evaluated via micro-computed tomography, mechanical testing (uniaxial compression), total fluorescent AGEs quantification, and Raman spectroscopy (matrix composition). BMD and microarchitecture measures did not differ between groups (p > 0.535). Compared to controls, T1D trabecular bone had higher AGE content (+42 %, p = 0.016), lower mineral-to-matrix ratio (-12 %, p = 0.048), trend toward lower crystallinity (-4 %, p = 0.054), and greater proline hydroxylation (+5 %, p = 0.007), but showed no differences in mechanical behavior (p ≥ 0.415). T2D trabecular bone also had elevated AGE (+60 %, p < 0.001) and altered matrix composition. Unlike T1D, T2D bone demonstrated improved ductility and post-yield energy dissipation versus control, with greater ultimate strain (+36 %, p = 0.008), post-yield strain (+62 %, p = 0.075), and toughness to ultimate force (+38 %, p = 0.044). This study reveals distinct effects of T1D and T2D on trabecular bone matrix composition, although these effects did not coincide with reduced mechanical properties under uniaxial compression loading.