Proteinuria and Albuminuria During and After Paricalcitol Treatment in Chronic Kidney Disease Patients.

Data on paricalcitol lowering albuminuria and proteinuria already exist; however, it is unclear how paricalcitol withdrawal affects both. Forty-two nondialysis chronic kidney disease (CKD) patients (29 men) aged 62.3 ± 12 years completed the study. CKD patients with proteinuria and intact parathyroid hormone ≥65 pg/mL received paricalcitol (1 μg/day po) for 6 months. After paricalcitol withdrawal we followed them for 6 more months. Paricalcitol treatment significantly reduced urinary albumin/creatinine ratio (UACR), 24-hour albuminuria (24hA), and 24-hour proteinuria (24hP). Six months after drug withdrawal UACR increased significantly, 24hA and 24hP did not change significantly. Serum creatinine and cystatin C significantly increased during treatment, and estimated glomerular filtration rate (eGFR) decreased. After drug withdrawal serum creatinine, cystatin C, and eGFR did not change significantly. In conclusion, 6-month paricalcitol treatment (1 μg/day) in nondialysis CKD patients significantly reduced albuminuria and proteinuria. Six months after paricalcitol withdrawal 24hA and 24hP did not change significantly. Kidney function decreased during paricalcitol treatment; after paricalcitol withdrawal it remained stable. The unaltered values of 24hA, 24hP, and kidney function after paricalcitol withdrawal could be a delayed effect of paricalcitol treatment.