Calcitriol Supplementation After Kidney Transplantation: Results of a Double-Blinded, Randomized, Placebo-Controlled Trial.
Khairallah, P., et al.Journal of Bone & Mineral Research 2025 [record in progress].
Aims
The aim of this study was to assess the role of calcitriol supplementation in renal transplant patients receiving early corticosteroid withdrawal immunosuppression.
Interventions
Participants were randomised to receive either calcitriol or placebo.
Participants
67 kidney transplant recipients receiving corticosteroid-sparing immunosuppressive regimen.
Outcomes
The primary outcome was pre- to post-calcitriol treatment percentage change in cortical density at the radius and tibia. Secondary outcomes were pre- to post-treatment percentage changes in areal bone mineral density (BMD); trabecular volumetric BMD, whole bone stiffness and failure load, cortical and trabecular microarchitecture, and vascular calcification load of the upper and lower extremities; and parathyroid hormone (PTH) levels and bone biomarkers.
Follow-up
12 months post-transplantation
CET Conclusions
Low bone mineral density (BMD) and fracture is common in kidney transplant recipients (KTR). Although modern steroid-reducing immunosuppression regimens have reduced the rate of fracture in these patients, there are reports of low BMD despite these strategies. KDIGO guidelines recommend treating vitamin D deficiency to prevent these complications. This randomised trial investigated the efficacy of calcitriol supplementation in the first year following kidney transplant in improving bone health. Primary outcomes included measures of bone strength (DXA and HR-pQCT scans) and serum calcium. There were only 27 patients in each of the treatment and control groups. There was no significant difference in measures of bone strength between the groups, but an increased rate of hypercalcaemia was found in the treatment group. The study has numerous limitations. In contrast to the KDIGO guidelines, none of the included patients had vitamin D deficiency at baseline, negating any potential treatment effect. As in the general population, fractures in KTRs occur at a higher rate in women but nearly all participants in this study were male. Also, by the authors’ own power calculation, much higher patient numbers would be required to detect a difference in BMD. Finally, the relevant clinical parameter – fracture rate – could not be assessed in the short follow up period.
Data analysis
Modified intention-to-treat analysis
Trial registration
ClinicalTrials.gov - NCT02224144