[Bone mineral density in patients with renal hyperparathyroidism undergoing surgery: relationship with bone parameters].

Background And Objectives: Hyperparathyroidism (HPT) in chronic kidney disease (CKD) may alter the composition and bone architecture, and cause fractures. The DEXA bone mineral density (BMD), used to predict fracture risk, measures the amount of calcium in bone. However, we do not know the relationship between BMD and bone composition.

Patient And Method: Our study, conducted in two groups of renal patients with HPT who underwent parathyroidectomy (PTX): patients on hemodialysis (HD group) and patients with renal transplant (RT group). The aims were to quantify and value the differences among groups and by gender on bone mineral density, quantify and define differences between these two groups and a control group regarding the elemental composition of bone marrow biopsy obtained and static parameters of bone histomorphometry, and define a possible relationship between bone mineral density and bone elements versus histomorphometric parameters.

Results: The BMD mean in femur was higher in TR group than in HD group. Linear correlation analysis performed between parameters versus BMD and bone histomorphometry elements, considering both TR and HD, only correlation between femur BMD (gr/cm2) and calcium (r=0.435, p=0.034, n=24) was observed.

Conclusion: Hyperparathyroidism patients undergoing renal transplant had better femoral BMD than those on hemodialysis; the trabecular volume was lower in kidney transplantation, while the volume of fibrosis was higher in hemodialysis patients; the elements in bone transplant and hemodialysis were in similar proportion, while the calcium content tended to be higher in renal transplant.