Reduction of Dialysate Calcium Level Reduces Progression of Coronary Artery Calcification and Improves Low Bone Turnover in Patients on Hemodialysis

Abstract

Exposure to high Ca concentrations may influence the development of low-turnover bone disease and coronary artery calcification (CAC) in patients on hemodialysis (HD). In this randomized, controlled study, we investigated the effects of lowering dialysate Ca level on progression of CAC and histologic bone abnormalities in patients on HD. Patients on HD with intact parathyroid hormone levels #300 pg/ml receiving dialysate containing 1.75 or 1.50 mmol/L Ca (n=425) were randomized to the 1.25-mmol/L Ca (1.25 Ca; n=212) or the 1.75-mmol/L Ca (1.75 Ca; n=213) dialysate arm. Primary outcome was a change in CAC score measured by multislice computerized tomography; main secondary outcome was a change in bone histomorphometric parameters determined by analysis of bone biopsy specimens. CAC scores increased from 4526869 (mean6SD) in the 1.25 Ca group and 5006909 in the 1.75 Ca group (P=0.68) at baseline to 61661086 and 80361412, respectively, at 24 months (P=0.25). Progression rate was significantly lower in the 1.25 Ca group than in the 1.75 Ca group (P=0.03). The prevalence of histologically diagnosed low bone turnover decreased from 85.0% to 41.8% in the 1.25 Ca group (P=0.001) and did not change in the 1.75 Ca group. At 24 months, bone formation rate, trabecular thickness, and bone volume were higher in the 1.25 Ca group than in the 1.75 Ca group. Thus, lowering dialysate Ca levels slowed the progression of CAC and improved bone turnover in patients on HD with baseline intact parathyroid hormone levels #300 pg/ml.

Effects of Lowering Dialysate Calcium Concentration on Bone Metabolic Markers in Hemodialysis Patients With Suppressed Serum Parathyroid Hormone: A Preliminary Study

“…Therefore, these results suggest that the lowering of dialysate Ca concentration improved bone remodeling in HD patients with probable lowturnover bone disease. In accordance with these results, Ok et al (8) recently reported that lowering dialysate Ca concentration improved low-turnover bone disease by bone biopsy.…”

Impact of vascular calcification on cardiovascular mortality in hemodialysis patients: clinical significance, mechanisms and possible strategies for treatment

“…In a recent randomized controlled study, effect of lowering the dialysate calcium level on the progression of CAC and the histologic bone abnormalities in 425 hemodialysis patients was examined [119]. As a result, progression rate of CAC was significantly lower in the low calcium dialysate (1.25 mmol/l) group than in the high calcium dialysate (1.75 mmol/l) group.…”

The Importance of Adherence in the Treatment of Secondary Hyperparathyroidism

“…No changes in H-DCa were found. At the end of follow-up, L-DCa group showed higher bone formation rate, trabecular thickness, and bone volume than H-DCa [20].…”