Type 2 Diabetes and Longitudinal Changes in Cortical and Trabecular Bone Density, Microarchitecture, and Strength:...

To gain insight into higher fracture risk in individuals with type 2 diabetes, we determined the association of type 2 diabetes glycemic status and severity with longitudinal changes in peripheral bone density and microarchitecture.

We conducted a longitudinal study of 769 participants from the Framingham Study who underwent high-resolution, peripheral, quantitative computed tomography (HR-pQCT) at the tibia and radius, in 2012-2016 and 2021-2023 (mean 8-year follow-up). Linear regression models estimated mean 8-year percent changes in bone measures, across indicators of diabetes severity, adjusting for age, sex, weight, and height.

The mean age was 67 ± 7 years, and 59% of participants were women. More than half (57%) were normoglycemic (fasting plasma glucose [FPG] <100 mg/dL, not on any treatment), 31% had prediabetes (100 ≤ FPG ≤125 mg/dL), and 12% had type 2 diabetes (FPG >125 mg/dL or on treatment). Adjusted mean percent changes in HR-pQCT bone measures were similar across diabetes severity, including glycemic status, use of diabetes medications, duration of diabetes, and HbA1c. For example, cortical volumetric bone mineral density at the radius changed by -1.50% (95% CI -2.43, -0.56) in type 2 diabetes and -1.96% (-2.53, -1.39), in prediabetes, compared with -2.42% (-2.86, -1.97) in normoglycemia (reference group; all P > 0.05).

The magnitude of peripheral bone loss over 8 years did not differ between individuals with type 2 diabetes and those with normoglycemia, suggesting that bone deterioration alone does not explain the higher fracture risk in older adults with type 2 diabetes. Future studies should address other contributors to skeletal fragility.