Comparison of the Effects of Paricalcitol and Calcitriol on Vascular Calcification in Patients Undergoing Chronic Hemodialysis

Introduction: Secondary hyperparathyroidism is considered an unconventional risk factor of vascular calcification in hemodialysis patients (HPs). An important factor of vascular calcification is vitamin D receptor activator used in the treatment of secondary hyperparathyroidism. This study aimed to investigate the change in pulse wave velocity (PWV) and fibroblast growth factor-23 (FGF-23), Klotho, and 25-hydroxyvitamin D [25(OH)D] levels as a result of 1-year treatment with paricalcitol or calcitriol among patients undergoing chronic dialysis. Methods: Eighty HPs were included in the study, and PWV measurements were obtained at the beginning and after 1 year of treatment. Serum Klotho and 25(OH)D levels were evaluated at the end of 1-year treatment with paricalcitol or calcitriol. Results: At the end of 1 year, FGF-23 levels in the paricalcitol group were significantly lower than those in the calcitriol group. Klotho and 25(OH)D levels were significantly higher in the paricalcitol group. The PWV at the beginning of the study was statistically similar between the two groups; in contrast, PWV at 1 year was significantly lower in the paricalcitol group than in the calcitriol group (p=0.002). When the PWV change was considered as the dependent variable, the most powerful determinant in multiple regression analysis was the FGF-23 level. Conclusion: In HPs, paricalcitol has a protective effect against vascular calcification compared with calcitriol treatment, owing to its positive effects on both parathyroid hormone and calcium-phosphorus balance. Therefore, paricalcitol should be the first choice in the treatment of secondary hyperparathyroidism.