Effect of vitamin D sterols on bone histology in pre-dialysis patients: A prospective controlled study

Autores da FMUP

• Ricardo Morais Pereira Neto

  Autor

• Janete Maria Quelhas Dos Santos

  Autor

• João Miguel Machado Dória Frazão

  Autor

Participantes de fora da FMUP

• Pereira, L
• Magalhaes, J

Unidades de investigação

• Laboratório Associado RISE- Rede de Investigação em Saúde

  

  Investigador

  Fernando Carlos De Landér Schmitt

• Medicina

• Recursos Comuns

  

  Investigador

  Guilhermina Maria Da Silva Rêgo

• RISE-Health

  

  Investigador

  Fernando Carlos De Landér Schmitt

Abstract

Background: Abnormalities related to mineral and bone metabolism are a common finding in chronic kidney disease (CKD). Vitamin D compounds are often prescribed to CKD patients with the purpose to control secondary hyperparathyroidism and reduce the risk of high-turnover bone disease. However, data on the effect of vitamin D sterols on bone histology in non-dialysis CKD is limited. Materials and methods: A prospective controlled study was conducted on a cohort of 56 patients with CKD stages 3 and 4. 19 patients on calcitriol and 12 patients on cholecalciferol were compared to a group of 25 age-and sex-matched controls. Participants underwent a tetracycline double-labelled transiliac bone biopsy before starting therapy and again 12 months later. Changes from baseline in circulating biomarkers and bone histomorphometric parameters were analyzed. Results: Low turnover bone disease was the most common pattern of renal osteodystrophy on the initial biopsy. There was no difference in biochemical or histomorphometric values between the three study groups at baseline. Serum intact parathormone (iPTH) and bone formation rate decreased significantly in calcitriol-treated patients, with prevalence of low-turnover bone disease doubling from baseline. In contrast, no significant changes were noted in cholecalciferol-treated and control subjects. Conclusion: Calcitriol was effective in preventing secondary hyperparathyroidism and high-turnover bone disease. However, it was associated with an increased risk of developing or aggravating low-turnover bone disease. In the absence of a bone biopsy, calcitriol use in pre-dialysis CKD should be reserved for patients with a progressive rise in iPTH levels, in whom high-turnover bone disease is suspected.

Keywords

• bone biopsy; pre-dialysis patients; bone histomorphometry; cholecalciferol; calcitriol&nbsp