Bone Microarchitecture and Strength in Long-Standing Type 1 Diabetes

Area of Science:

• Endocrinology
• Metabolic Bone Disease
• Diabetology

Background:

• Type 1 diabetes (T1DM) is associated with increased fracture risk, especially at nonvertebral sites.
• The impact of glycemic control and microvascular complications on bone health in long-standing T1DM is not well understood.

Purpose of the Study:

• To evaluate bone mineral density (aBMD, vBMD), microarchitecture, turnover, and estimated bone strength in patients with long-standing T1DM (≥25 years duration).
• To investigate the role of diabetic neuropathy in skeletal health alterations.

Main Methods:

• Recruited 59 patients with T1DM and 77 controls.
• Utilized dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HRpQCT).
• Assessed biochemical markers of bone turnover and employed finite element modeling for bone strength estimation.

Main Results:

• T1DM patients exhibited lower hip, distal radius, lumbar spine, and femoral neck aBMD.
• Bone resorption marker (CTX) was lower in T1DM patients.
• Reduced cortical thickness and vBMD at the ultradistal tibia, leading to decreased bone strength and stiffness, were observed in T1DM.
• These cortical alterations and reduced bone strength were dependent on the presence of diabetic peripheral neuropathy.

Conclusions:

• Long-standing, well-controlled T1DM is associated with reduced areal bone density and bone resorption.
• A significant cortical bone deficit at the ultradistal tibia, compromising bone strength and stiffness, is present in T1DM.
• Diabetic neuropathy is a key determinant of tibial cortical bone structure and strength, potentially explaining the elevated nonvertebral fracture risk in T1DM patients.