Bone microarchitecture declines in older men with impaired renal function-the prospective STRAMBO study

Area of Science:

• Nephrology and Bone Metabolism
• Geriatric Medicine
• Radiology and Imaging

Background:

• Chronic kidney disease (CKD) is frequently associated with mineral and bone disorders (CKD-MBD).
• Limited data exist on the relationship between estimated glomerular filtration rate (eGFR) and bone microarchitecture.
• Understanding this link is crucial for assessing fracture risk in aging populations with CKD.

Purpose of the Study:

• To investigate the association between eGFR and bone microarchitecture at baseline and over time.
• To assess changes in bone structure and strength in relation to eGFR in older men.
• To explore the potential contribution of eGFR-related bone changes to fracture risk.

Main Methods:

• Longitudinal study of 826 men aged ≥60 years over 8 years.
• eGFR calculated using three established equations (CKDEPI-2012, EKFC, CKDEPI-2021).
• Bone microarchitecture assessed via high-resolution peripheral quantitative computed tomography (HR-pQCT) at distal radius and tibia.
• Bone strength estimated using microfinite element analysis; changes analyzed with linear mixed-effect models.

Main Results:

• At baseline, lower eGFR was associated with higher trabecular measures and failure load at the distal tibia.
• Over 8 years, lower eGFR correlated with accelerated decreases in bone mineral density, cortical area, and bone strength at the distal radius.
• Lower eGFR also predicted faster increases in trabecular area and heterogeneity at the distal radius, and declines in bone density and strength at the distal tibia.

Conclusions:

• Reduced eGFR is significantly associated with accelerated deterioration of cortical bone microarchitecture and reduced bone strength in older men.
• These microarchitectural changes at both the radius and tibia may underlie the elevated fracture risk observed in older adults with CKD.
• Findings highlight the importance of monitoring bone health in aging individuals with declining kidney function.