Effects of cholecalciferol supplementation in Autosomal Dominant Polycystic Kidney Disease (ADPKD) patients

Introduction: Hypertension and inflammation have been associated with Autosomal Dominant Polycystic Kidney Disease (ADPKD) progression. We have previously observed an inverse correlation between serum levels of 25-hydroxyvitamin D [25(OH)D] and vitamin D receptor (VDR) expression with total kidney volume, a surrogate marker of disease progression. The present study aimed to determine the effects of a short-term cholecalciferol supplementation upon arterial pressure, hormonal, biochemical parameters and inflammatory markers in ADPKD patients with hypovitaminosis D. Methods: Vitamin D-insufficient ADPKD patients (15 M/27F, 41.5 +/- 11.8 years) with an estimated Glomerular Filtration Rate (eGFR) of 75.4 +/- 34.6 mL/min/1.73 m(2) were randomly assigned to receive a single monthly dose of vitamin D-3 or placebo for 3 months. Blood pressure (BP) was measured through 24-h ambulatory BP monitoring (ABPM), serum 25(OH)D levels, monocyte expression of its regulatory enzymes (CYP24A1 and CYP27B1) and VDR, as well as inflammatory markers (IL-6, IL-10, CRP and NFkB serum levels) were determined at baseline and at the end of the study. Results: At the end of the study, [25(OH)D] levels have been restored in cholecalciferol group (37 +/- 10 versus 19 +/- 4 ng/mL, p < 0.001) but not in placebo (22 +/- 5 versus 22 +/- 6 ng/mL, p = 0.83). However, VDR, CYP24A1/ CYP27B1 monocyte expression, inflammatory markers and ABPM parameters were not statistically different from baseline. Conclusion: Present findings suggested that a short-term cholecalciferol supplementation in the current doses was not able to modify inflammatory nor blood pressure parameters in ADPKD patients with 25(OH)D insufficiency.