Effects of Dialysate Calcium Concentration and Calcitriol on Bone Metabolism in Hemodialysis Patients / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: Whereas higher dialysate calcium (Ca) levels may pose a risk of hypercalcemia, lower levels may induce a negative Ca balance. We evaluated the effect of lowering dialysate Ca levels from 1.75 to 1.5 mmol/L and explored the appropriate use of calcitriol to regulate bone metabolism in hemodialysis patients. METHODS: The dialysate Ca levels of 36 patients were reduced from 1.75 to 1.5 mmol/L. They were divided into three groups according to basal intact parathyroid hormone (iPTH) level (group 1, iPTH 300 pg/mL, n = 8). Data were collected at 3-month intervals for 1 year. RESULTS: Throughout the study period, no significant difference in phosphate binders, serum Ca, phosphorus (P), or Ca x P products was observed among groups. However, iPTH, alkaline phosphatase (AP), and calcitriol dosage patterns differed among groups. In group 1, iPTH and AP increased significantly over 12 months (p = 0.01). In group 2, iPTH and AP showed no significant changes. In group 3, iPTH and AP declined significantly over 12 months (p = 0.02). Calcitriol dosage did not change in groups 1 and 2, but increased significantly in group 3 (p = 0.001). CONCLUSIONS: After converting hemodialysate Ca levels from 1.75 to 1.5 mmol/L, the initially different iPTH concentrations converged to a modestly elevated level. The use of 1.5 mmol/L hemodialysate Ca may thus be appropriate for both high- and low-turnover bone disease if phosphate binders and calcitriol are combined appropriately.