Association between CKD-MBD and hip-bone microstructures in dialysis patients

TL;DR

This study finds that high parathyroid hormone levels are linked to worsening hip bone structure in dialysis patients, suggesting better PTH management could help preserve bone health.

Contribution

The study identifies elevated parathyroid hormone (PTH) as a key factor in hip-bone deterioration in dialysis patients, challenging the assumption that low PTH is harmful.

Findings

Elevated PTH levels were significantly associated with decreased bone mineral density and structural deterioration in dialysis patients.

Lower PTH groups showed positive correlations with improved bone density metrics.

Serum calcium and phosphate levels were not significantly linked to changes in bone microstructure or strength.

Abstract

The longitudinal changes in hip-bone microstructures and estimated bone strength in dialysis patients, and the impact of chronic kidney disease–mineral and bone disorder (CKD-MBD) biomarkers on these changes, remain insufficiently explored.

This retrospective study examined changes in cortical and trabecular bone compartments and estimated bone-strength indices, obtained by using 3D-SHAPER software, in the hip regions of 276 dialysis patients over up to 2.5 years. We used multivariate mixed models to investigate the associations between time-dependent CKD-MBD biomarkers and bone health metrics.

There was a significant decrease in areal bone mineral density (aBMD), integral volumetric BMD (vBMD), trabecular vBMD, cortical thickness and cortical surface BMD (sBMD). Similar deteriorations were found in estimated bone-strength indices [cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (SM) and buckling ratio]. Neither serum calcium nor phosphate levels were significantly associated with changes in three-dimensional parameters or estimated bone-strength indices. In contrast, serum alkaline phosphatase levels showed a significant inverse correlation with aBMD and CSA. The intact-parathyroid hormone (i-PTH) was significantly inversely correlated with aBMD, integral vBMD, trabecular vBMD, cortical thickness, cortical vBMD, CSA, CSMI and SM. When applying the KDIGO criteria as a sensitivity analysis, the higher PTH group had significant negative associations with aBMD, integral vBMD, cortical vBMD, cortical thickness and cortical sBMD. Notably, the lower PTH group showed a positive significant correlation with integral vBMD and trabecular vBMD.

Elevated PTH, not low PTH, was associated with deterioration of hip-bone microstructures. Better management of PTH levels may play a crucial role in the hip-bone microstructure in dialysis patients.

Graphical Abstract

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