Accelerated Bone Loss in Older Men: Effects on Bone Microarchitecture and Strength

Area of Science:

• Orthopedics
• Gerontology
• Radiology

Background:

• Accelerated bone loss (ABL) detected by dual-energy X-ray absorptiometry (DXA) may indicate underlying microarchitectural deterioration and reduced bone strength.
• Understanding these changes is crucial for assessing fracture risk in aging populations.

Purpose of the Study:

• To investigate the association between accelerated bone loss and detailed bone microarchitecture and estimated bone strength using high-resolution peripheral quantitative computed tomography (HR-pQCT).

Main Methods:

• A cross-sectional study of 1628 men from the Osteoporotic Fractures in Men (MrOS) study.
• Retrospective characterization of areal bone mineral density (aBMD) change over 7 years into 'accelerated' (≥10% loss), 'expected' (<10% loss), and 'maintained' (≥0% gain) categories.
• HR-pQCT scans assessed bone microarchitecture and estimated bone strength in the distal radius and tibia.

Main Results:

• Men with ABL were older, had lower BMI and aBMD, and experienced greater weight loss.
• ABL was associated with lower total volumetric BMD, trabecular volumetric BMD, and cortical volumetric BMD.
• Significantly poorer trabecular bone structure (lower BV/TV, fewer trabeculae, greater separation) and thinner cortices were observed in men with ABL.
• Estimated bone strength was lower in the ABL group, with no significant difference in cortical porosity except at the tibial diaphysis.

Conclusions:

• Men experiencing accelerated bone loss exhibit compromised bone microarchitecture and reduced bone strength compared to those with expected or maintained bone density.
• These skeletal impairments associated with ABL may contribute to an elevated risk of fractures.