Clinical benefit of the change of dialysate calcium concentration from 3.0 to 2.75 mEq/L

Because active vitamin D preparations and calcimimetics have been widely used to treat secondary hyperparathyroidism, maintenance of acceptable serum calcium and phosphate levels is important. A 2.75 mEq/L dialysate calcium product, which may bring the calcium balance closer to 0, has recently been launched, and we had an opportunity to examine its possible benefits. We performed a 6-month retrospective review after switching from 3.0 mEq/L to 2.75 mEq/L calcium dialysate in 85 outpatients undergoing chronic hemodialysis. We evaluated blood biochemical parameters, including predialysis and postdialysis serum calcium and phosphate levels, predialysis intact parathyroid hormone (iPTH) levels; dialysis dose (Kt/V); and doses of concomitant active vitamin D preparations, calcimimetics, phosphate binder, and erythropoiesis-stimulating agents. Postdialysis calcium levels were significantly lower and predialysis corrected calcium levels significantly decreased. The change in calcium levels before and after dialysis was smaller after switching of the dialysate than before. iPTH levels significantly increased 1 month after switching of the dialysate. No remarkable changes were observed in phosphate levels or Kt/V. The dose of alfacalcidol, one of the concomitant drugs, somewhat increased, and no remarkable changes in dosage were observed for other concomitant drugs. These results were favorable in terms of calcium balance. However, there may be limitations in interpreting the results, but the resultant calcium levels suggest that switching to 2.75 mEq/L calcium dialysate may improve the control of calcium levels. In addition, it is hoped that the treatment choice of secondary hyperparathyroidism is extended.