title: Alterations in serum phosphate levels predict the long-term response to intravenous calcitriol therapy in dialysis patients with secondary hyperparathyroidism.
abstract: Calcitriol therapy is a central strategy for the treatment of uremic secondary hyperparathyroidism. Although indiscriminate use of calcitriol may lead to worse outcomes, it is difficult to make a decision to discontinue calcitriol therapy when its parathyroid suppression effect remains unsatisfactory. In this study, intravenous calcitriol was administered to 120 chronic hemodialysis patients. Therapy continued for 48 weeks or until plasma intact parathyroid hormone (iPTH) levels decreased to below 300 pg/ml or until the development of any significant adverse effect. Of the 120 patients, the treatment goal was achieved in 47 patients during the first 4 weeks, in 10 during the next 4 weeks, and in 22 patients thereafter. Logistic regression analysis and stepwise regression analysis revealed that iPTH levels were the only significant predictor of the response to calcitriol therapy at weeks 0 and 4. Besides iPTH, the inorganic phosphate (P) levels were another significant predictor of the ultimate response to calcitriol therapy at week 8. The point of best discrimination for successful treatment was P = 6.0 mg/dl at week 8, or P level at week 8/pretreatment P level = 1.0. In conclusion, the P level at week 8 is a predictor of the response to calcitriol therapy for uremic secondary hyperparathyroidism. Changes in treatment are recommended if patients show unsatisfactory parathyroid suppression with a hyperphosphatemic tendency.
authors.affiliation: Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, 1-751 Asahimachi-dori, Niigata, Niigata 951-8510, Japan.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Hosaka
authors.forename: Junichiro James
authors.initials: JJ
authors.lastname: Kazama
authors.forename: Suguru
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ito
authors.forename: Noriaki
authors.initials: N
authors.lastname: Iino
authors.forename: Hiroki
authors.initials: H
authors.lastname: Maruyama
authors.forename: Akihiko
authors.initials: A
authors.lastname: Saito
authors.forename: Ichiei
authors.initials: I
authors.lastname: Narita
authors.forename: Fumitake
authors.initials: F
authors.lastname: Gejyo
mesh_terms: D002117:Calcitriol / Q000008:administration & dosage* / Q000627:therapeutic use*; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood* / Q000188:drug therapy*; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000097:blood*; D012372:ROC Curve; D012044:Regression Analysis; D006435:Renal Dialysis; D013997:Time Factors
chemical_list: D010710:Phosphates; D002117:Calcitriol; D002118:Calcium