Oral Paricalcitol in the Treatment of Patients With CKD and Proteinuria: A Randomized Trial
Received 24 November 2008; accepted 7 April 2009. published online 14 July 2009.
Background
Vitamin D has key roles in regulating systems that could be important in the pathobiological state of proteinuria. Because of this, it could be helpful in treating patients with proteinuric renal diseases. The objective is to determine the effect of oral paricalcitol on protein excretion in patients with proteinuric chronic kidney disease.
Study Design
Double-blind randomized study.
Setting & Participants
61 patients with estimated glomerular filtration rate of 15 to 90 mL/min/1.73 m2 and protein excretion greater than 400 mg/24 h.
Intervention
Randomization to 6 months of treatment with paricalcitol, 1 μg/d, or placebo.
Outcomes & Measurements
The predefined primary end point was to compare change in mean spot urinary protein-creatinine ratio between the baseline measurement and the last study evaluation (6 months in study completers) between the 2 groups. Every 4 weeks, there was measurement of serum intact parathyroid hormone, serum calcium, serum phosphorus, serum creatinine, and urine spot protein and creatinine.
Results
At baseline, mean urinary protein-creatinine ratios were 2.6 and 2.8 g/g in the placebo and paricalcitol groups, respectively. At final evaluation, mean ratios were 2.7 and 2.3, respectively. Changes in protein excretion from baseline to last evaluation were +2.9% for controls and −17.6% for the paricalcitol group (P = 0.04). A 10% decrease in proteinuria occurred in controls (7 of 27; 25.9%) and the paricalcitol group (16 of 28; 57.1%; P = 0.03).
Limitations
The relatively small sample size limits the extent to which results should be generalized.
Conclusions
Paricalcitol resulted in a significant reduction in protein excretion in patients with proteinuric renal disease.
ABSTRACT