Risk Factors for Bone Microarchitecture Impairments in Older Men With Type 2 Diabetes—The MrOS Study

Context: Impaired bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), may contribute to bone fragility in type 2 diabetes (T2DM) but data on men are lacking. Objective: To investigate the association between T2DM and HR-pQCT parameters in older men. Methods: HR-pQCT scans were acquired on 1794 participants in the Osteoporotic Fractures in Men study. T2DM was ascertained by self-report or medication use. Linear regression models, adjusted for age, race, body mass index, limb length, clinic site, and oral corticosteroid use, were used to compare HR-pQCT parameters by diabetes status. Results: Among 1777 men, 290 had T2DM (mean age, 84.4 years). T2DM men had smaller total cross-sectional area at the distal tibia (P = .028) and diaphyseal tibia (P = .025), and smaller cortical area at the distal (P = .009) and diaphyseal tibia (P = .023). Trabecular indices and cortical porosity were similar between T2DM and non-T2DM. Among men with T2DM, in a model including HbA1c, diabetes duration, and insulin use, diabetes duration ≥ 10 years, compared with <10 years, was significantly associated with higher cortical porosity but with higher trabecular thickness at the distal radius. Insulin use was significantly associated with lower cortical area and thickness at the distal radius and diaphyseal tibia and lower failure load at all 3 scan sites. Lower cortical area, cortical thickness, total bone mineral density, cortical bone mineral density, and failure load of the distal sites were associated with increased risk of incident nonvertebral fracture in T2DM. Conclusion: Older men with T2DM have smaller bone size compared to those without T2DM, which may contribute to diabetic skeletal fragility. Longer diabetes duration was associated with higher cortical porosity and insulin use with cortical bone deficits and lower failure load.