Bone Microarchitecture in Men and Women with Diabetes: The Importance of Cortical Porosity

High-resolution peripheral quantitative computed tomography (HR-pQCT) captures novel aspects of bone geometry, volumetric bone mineral density and offers the ability to measure bone microarchitecture, but data relating measures obtained from this technique to diabetic status are inconsistent in women and lacking in men. Here, we report an analysis from the Hertfordshire Cohort Study, where we were able to study associations between bone microarchitecture from HR-pQCT of distal radius and distal tibia in 332 participants (177 men and 155 women) aged 72.1-81.4 years with or without diabetes mellitus (DM); n = 29 (18 men and 11 women) and n = 303, respectively. Statistical analyses were performed separately for women and men. The mean (SD) age of participants was 76.4 (2.6) and 76.1 (2.5) years in women and men, respectively. Participants with DM differed significantly in terms of weight in both women (70.4 +/- 12.3 vs. 80.3 +/- 18.3 kg; p = 0.015) and men (81.7 +/- 11.4 vs. 92.8 +/- 16.3 kg; p < 0.001) but no differences were found in height, smoking status, alcohol intake, social class and physical activity among women or men. Analyses in women revealed that cortical pore volume (Ct.Po.V) was higher in participants with DM and close to statistical significance for cortical porosity (Ct.Po) (beta = 0.76 [0.12, 1.41] z-score, p = 0.020 and beta = 0.62 [-0.02, 1.27] z-score, p = 0.059, respectively) at the distal radius. Adjustment for weight did not materially affect the relationship described for Ct.Po.V (beta = 0.74 [0.09, 1.39], p = 0.027) and Ct.Po (beta = 0.65 [-0.01, 1.30], p = 0.053) at the distal radius. After adjustment for weight, analyses in men revealed that Ct.Po and Ct.Po.V were higher in participants with DM (beta = 0.57 [0.09, 1.06] z-score, p = 0.021 and beta = 0.48 [0.01, 0.95] z-score, p = 0.044, respectively) at the distal tibia. Analyses of distal radial and tibial trabecular bone parameters according to diabetic status revealed no significant differences among men or women after adjustment for weight. We found higher cortical porosity and cortical pore volume at the distal tibia in men with DM and higher cortical pore volume at the distal radius in women with a non-significant tendency for higher cortical porosity. The results of our study suggest that deficits in cortical bone exist both in older men and women with DM.