A Prospective Study of the Effect of Calcitriol Treatment according to Administration Route in CAPD Patients

Lee, In Hee; Kang, Shin Wook; Noh, Hyun Jin; Shin, Sug Kyun; Kim, Eun Kyung; Choi, Kyu Hun; Ha, Sung Kyu; Yoo, Hyung Sik; Lee, Ho Yung; Han, Dae Suk

Abstract

To determine the optimal administration route of calcitriol in CAPD patients with secondary hyperparathyroidism, we conducted a prospective study on 33 patients who performed CAPD for more than 6 months an d whose intact parathyroid hormone(iPTH) level was higher than 250pg/mL. The patients were randomized into 3 groups:IP(n=11); 1.0 microgram of calcitriol once daily via intraperitoneal route by overnight retention with dialysate, SC(n=11); 1.0 microgram of calcitriol three times a week via subcutaneous route, and PO (n=11); 1.0 microgram of calcitriol three times a week by ingestion. 11 out of 33 patients(6 in IP, 4 in SC, and 1 in PO) dropped out during the 6-months study period, and 5 among the 6 patients in IP were due to recurrent peritonitis. Biochemical data including calcium, phosphorus, iPTH, alkaline phosphatase, bone-specific alkaline phosphatase, osteocalcin and 1,25(OH)2D3 were measured regularly, and the data of 22 patients who had completed the 6-months study were analyzed. There was a statistically significant decrease in iPTH level(pg/mL) in the three groups after 6-months calcitriol therapy(IP; 812.0+/-276.7 vs. 354.7+/-129.4, PO; 571.8+/-330.7 vs. 159.6+/-192.3, SC; 786.1+/-535.0 vs. 551.8+/-729.9, respectively, P<0.05), but there were no differences in the percentage of decrease in iPTH from baseline values among the three groups. Alkaline phosphatase, bone- specific alkaline phosphatase and osteocalcin also decreased significantly in all three groups(IP; 50.1+/-14.6, 33.5+/-11.6, 52.3+/-10.9% of baseline value; SC; 80.9+/-14.8, 67.4+/-20.80, 54.4+/-11.1% of baseline value; PO; 48.8+/-24.4, 36.6+/-23.5, 54.2+/-11.6% of baseline value, respectively, P<0.05), but they were not different with each other. Among 22 patients who completed the 6-months study, hypercalcemia(Ca>=10.5 mg/dL) occurred in 7 patients(31.8%). IP(2/5, 40%) and SC groups(5/7, 71.4%) had significantly higher incidence of hypercalcemia than PO group(0/10, 0%) (P<0.05). IP group(2/5, 40%) also experienced significantly higher incidence of hyperphosphatemia than SC(1/7, 14.3%) and PO groups(1/10, 10%). Peritonitis occurred significantly more in IP than in SC and PO groups(P<0.05). In conclusion, calcitriol treatment resulted in a significant decrement in iPTH levels in CAPD patients and no significant differences were noted in the iPTH-suppressive effect of calcitriol according to the administration route. Because of higher incidence of peritonitis and hypercalcemia in IP and SQ groups, oral ingestion may be the most optimal route for calcitriol treatment in CAPD patients with secondary hyperparathyroidism.