Treatment of secondary hyperparathyroidism with paricalcitol in patients with end-stage renal disease undergoing hemodialysis in Turkey: an observational study.

OBJECTIVE: To evaluate monthly percentage changes of intact parathyroid hormone (iPTH) and other major bone marker levels in patients with secondary hyperparathyroidism (SHPT) undergoing hemodialysis (HD) and receiving paricalcitol. METHODS: A total of 493 (F/M 244/249) adult patients with SHPT who were undergoing HD in 22 HD units and receiving paricalcitol treatment, with iPTH > 300 mg/mL, adjusted serum levels of calcium (Ca) < 10.2 mg/dL, and serum levels of inorganic phosphorus (iP) < 6 mg/dL were included in this multi-center, national, prospective, observational study. Data regarding efficacy, safety, and adverse events of paricalcitol treatment were collected during a 12-month follow-up period through monthly visits along with serum iPTH, Ca, iP, alkaline phosphatase (ALP) and other required biochemistry tests as necessary. Mortality data until 6 months after the end of the study were also investigated. RESULTS: The mean age was 58.3 ± 15.8 years and the mean duration of HD was 6.2 ± 5.5 years, respectively. As of 12th month, mean iPTH values decreased from 646 ± 424 pg/mL to 473 ± 387 pg/mL (p < 0.001); no statistically significant changes were observed in Ca levels (p > 0.05). Serum ALP levels also significantly decreased (p = 0.001) and serum phosphorus levels significantly increased (p < 0.001) during the study observation period. Reasons for early terminations were being lost to follow-up (n = 119, 24.1%), hyperphosphatemia (iP > 6 mg/dL, n = 108, 21.9%), low iPTH levels (iPTH < 150 mg/dL, n = 97, 19.7%), and withdrawal of consent (n = 41, 8.3%). In total 32 patients (6.5%) were prematurely terminated the study with hypercalcemia (Ca > 10.2 mg/dL). 46.9% of those hypercalcemic patients had other anomalies with iP and iPTH levels along with hypercalcemia. CONCLUSION: Paricalcitol treatment, resulted in successful iPTH control. In approximately 6.5% of the patients paricalcitol treatment was discontinued since Ca levels reached > 10.2 mg/dL in those patients. No unfavorable effects on serum phosphorus and Ca-phosphorus (Ca × P) product were observed.