Salusky I B, Kuizon B D, Belin T R, Ramirez J A, Gales B, Segre G V, Goodman W G
Department of Pediatrics, UCLA School of Medicine, Los Angeles, California, USA.
Kidney Int. 1998 Sep;54(3):907-14. doi: 10.1046/j.1523-1755.1998.00045.x.
Intermittent oral or intravenous doses of calcitriol given two or three times per week are commonly used to treat secondary hyperparathyroidism (secondary HPT). This study was undertaken to compare the biochemical and skeletal responses to thrice weekly intraperitoneal (i.p.) versus oral doses of calcitriol in children with secondary HPT undergoing peritoneal dialysis (CCPD).
Forty-six patients aged 12.5+/-4.8 years on CCPD for 22+/-25 months were randomly assigned to treatment with oral (p.o.) or i.p. calcitriol for 12 months; 17 subjects given p.o. calcitriol and 16 subjects given i.p. calcitriol completed the study. Bone biopsies were performed at the beginning and at the end of the study, while determinations of serum and total ionized calcium, phosphorus, alkaline phosphatase, parathyroid hormone (PTH) and calcitriol levels were done monthly.
Serum total and ionized calcium levels were higher in subjects treated with i.p. calcitriol, P < 0.0001, whereas serum phosphorus levels were higher in those given p.o. calcitriol, P < 0.0001. For the i.p. group, serum PTH levels decreased from pre-treatment values of 648+/-125 pg/ml to a nadir of 169+/-57 pg/ml after nine months. In contrast, serum PTH levels did not change from baseline values of 670+/-97 pg/ml in subjects given p.o. calcitriol, P < 0.0001 by multiple regression analysis. Serum alkaline phosphatase levels were also lower in patients treated with i.p. calcitriol, P < 0.0001, but there was no difference between groups in the average dose of calcitriol given thrice weekly. The skeletal lesions of secondary HPT improved in both groups, 33% of patients developed adynamic bone lesion.
Differences in the bioavailability of calcitriol and/or in phosphorus metabolism may account for the divergent biochemical response to p.o. and i.p. calcitriol.
每周两到三次间歇性口服或静脉注射骨化三醇常用于治疗继发性甲状旁腺功能亢进（继发性甲旁亢）。本研究旨在比较接受持续性非卧床腹膜透析（CCPD）的继发性甲旁亢患儿，每周三次腹膜内（i.p.）与口服骨化三醇的生化及骨骼反应。
46例年龄为12.5±4.8岁、接受CCPD治疗22±25个月的患者被随机分配接受口服（p.o.）或腹膜内骨化三醇治疗12个月；17例接受口服骨化三醇治疗的受试者和16例接受腹膜内骨化三醇治疗的受试者完成了研究。在研究开始和结束时进行骨活检，同时每月测定血清和总离子钙、磷、碱性磷酸酶、甲状旁腺激素（PTH）和骨化三醇水平。
接受腹膜内骨化三醇治疗的受试者血清总钙和离子钙水平较高，P<0.0001，而接受口服骨化三醇治疗的受试者血清磷水平较高，P<0.0001。对于腹膜内给药组，血清PTH水平从治疗前的648±125 pg/ml在9个月后降至最低点169±57 pg/ml。相比之下，接受口服骨化三醇治疗的受试者血清PTH水平与基线值670±97 pg/ml相比没有变化，多因素回归分析显示P<0.0001。接受腹膜内骨化三醇治疗的患者血清碱性磷酸酶水平也较低，P<0.0001，但两组每周三次给予的骨化三醇平均剂量没有差异。两组继发性甲旁亢的骨骼病变均有改善，33%的患者出现骨无动力性病变。
骨化三醇生物利用度和/或磷代谢的差异可能是口服和腹膜内骨化三醇生化反应不同的原因。
