abstract
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The risk of fracture is higher in adults with type 2 diabetes compared to controls without type 2 diabetes, despite normal or higher than normal bone mineral density (BMD). In addition to BMD, bone strength depends on other factors such as structural and material bone qualities, which are not accounted for in BMD measurements. The objective was to determine whether structural and material bone qualities are different in adults with type 2 diabetes compared to controls without type 2 diabetes. First, a cross-sectional study was undertaken using MRI to investigate distal radius trabecular bone microarchitecture, a structural bone quality. In women with type 2 diabetes, trabecular bone holes were larger compared to controls, which is important because greater trabecular bone hole size is related to reduced bone strength. Next, a two year prospective study was conducted with the participants involved in the cross-sectional study to determine whether changes in trabecular bone microarchitecture are different in women with type 2 diabetes compared to controls. There was a greater increase in the number of trabecular bone holes in women with type 2 diabetes compared to controls, which provides early evidence of trabecularization of cortical bone in women with type 2 diabetes. In the third study, quantitative backscattered electron imaging (qBEI) was used to derive bone mineralization density distribution (BMDD) outcomes for bone samples from adults with and without type 2 diabetes to compare material bone quality. There was evidence of elevated bone calcium concentration and reduced mineralization heterogeneity in bone samples from adults with type 2 diabetes compared to controls, which may contribute to bone brittleness. In summary, differences in structural and material bone qualities identified in this body of work provide explanations for elevated fracture risk in adults with type 2 diabetes.