Effect of Lower Calcium Dialysate on Laboratory Abnormalities in Chronic Kidney Disease–Associated Mineral and Bone Disorder

Abstract

Increased vascular calcification, possibly due to the biochemical problem of calcium (Ca) and phosphate excess, has been associated with cardiovascular disease in patients with end stage renal disease. The use of a lower dialysate Ca concentration (<2.50 mEq/L) has been postulated as one of the methods to prevent long-term Ca accumulation. Concern, however, has been raised over the possibility that using a low Ca dialysate may lead to an increase in the intact parathyroid hormone concentration and therefore the need for higher doses of vitamin D analogs. This may thus mitigate the much desired long-term benefits. With an aim to decrease the total Ca load in our patients, the standard dialysate Ca concentration in our outpatient dialysis center was decreased from 2.5 to 2.25 mEq/L in September 2009. We found that the use of a lower Ca dialysate in our maintenance hemodialysis patients led to a significant reduction in the mean serum Ca concentration without a significant increase in serum parathyroid hormone levels or an increase in vitamin D analogs/Ca-based phosphate binder dose requirements. Further prospective studies are needed to assess the impact of this intervention on long-term cardiovascular morbidity and mortality.