Corticosteroid, Parathyroid Hormone, and Body Composition Associations With Bone Density and Structure Following...

Area of Science:

• Nephrology
• Orthopedics
• Bone Metabolism

Background:

• Kidney transplantation (KTxp) can improve CKD-related skeletal fragility but is associated with increased fracture risk.
• Understanding post-KTxp changes in body composition and mineral metabolism is crucial for bone health.

Purpose of the Study:

• To assess the impact of changes in body composition and mineral metabolism on bone mineral density (BMD) and structure after kidney transplantation.
• To identify factors influencing bone health changes in kidney transplant recipients.

Main Methods:

• A 24-month prospective cohort study involving 60 incident kidney transplant recipients and 361 healthy controls.
• Measurements included bone mineral density (BMD), volumetric BMD (vBMD), cortical dimensions, appendicular lean mass index (ALMI), and fat mass index (FMI) using DXA and pQCT.
• Quasi-least squares regression models analyzed correlates of change.

Main Results:

• Recipients had lower baseline bone density and lean mass compared to controls.
• Within 6 months post-KTxp, lean mass, fat mass, and BMI increased, while some bone measures declined.
• Cortical vBMD increased from 6 months onward, linked to decreasing PTH. Cortical thickness progressively declined.
• Higher BMI and ALMI correlated with improved bone density; corticosteroid dose negatively impacted bone measures.

Conclusions:

• Skeletal deficits in kidney transplant recipients generally stabilize or improve after six months, with notable exceptions like progressive cortical thinning.
• Interventions to preserve cortical bone before and after transplantation are necessary.
• Increases in BMI and ALMI may positively influence bone health in weight-bearing areas post-transplantation.