Effect of off-label vitamin D analog use for albuminuria in early nondiabetic nephropathy: a double-blind, randomized, placebo-controlled trial.

Abstract

Background: Albuminuria is one of the factors promoting the progression of chronic kidney disease (CKD). The study aimed to assess the efficacy and safety of calcitriol for the reduction of microalbuminuria in patients with nondiabetic nephropathy.

Methods: In this randomized, double-blind, placebo-controlled, and multicenter study, adult patients with nondiabetic CKD stage 3 or greater and albuminuria were included. Participants were administered calcitriol or placebo for 6 months and followed for up to 12 months. The primary outcome was the change in urine protein-to-creatinine ratio (UPCR), and secondary outcomes included the changes in renal function and vitamin D level. The safety was assessed by recording adverse events during the treatment and follow-up.

Results: A total of 159 subjects were enrolled. The UPCR at 24 and 48 weeks was significantly decreased compared to the baseline in the calcitriol group (ΔUPCR, -0.24 g/g [95% CI, -0.43 to -0.05] and -0.22 g/g [95% CI, -0.43 to -0.01], respectively), but the mean changes of UPCR during 24 weeks and 48 weeks were no significant difference between the two groups. No significant differences were in the change in renal function and vitamin D level. Seventy-eight adverse events were reported during the treatment phase, and there were no significant differences in the type or frequency of adverse events between the two groups.

Conclusion: Although calcitriol treatment showed a significant reduction of proteinuria from baseline, the effect was insufficient in nondiabetic CKD compared to placebo. Therefore, the use of calcitriol for the reduction of albuminuria is worth considering.