Increasing Magnesium in Dialysis Fluid Delays Crystal Formation Time in Patients On Hemodialysis

What is it about?

It has long been known that there are many different promoters and inhibitors of calcification in blood. Recently, a new blood test, the serum calcification propensity, has become available, which measures how quickly calcium and phosphate precipitate in serum. When the net effect of calcification promoters outweighs the effect of calcification inhibitors precipitation occurs more rapidly. Rapid serum calcification propensity is associated with higher risk of cardiovascular events and death in patients with kidney disease. Magnesium, a known inhibitor of mineral precipitation, delays the serum calcification propensity in vitro. We therefore hypothesized that increasing dialysate magnesium would increase serum magnesium and thereby delay serum calcification propensity. We conducted a single-center, randomized, double-blinded, controlled clinical trial, in which we examined the effect of increasing dialysate magnesium from 1 mEq/L to 2 mEq/L on serum calcification propensity in patients treated with maintenance hemodialysis. The primary endpoint was the between-group difference in serum calcification propensity after 4 weeks of treatment. The results of the trial show that in the standard dialysate magnesium group, serum magnesium and calcification propensity were unchanged throughout the intervention, while in the high dialysate magnesium group there was a significant increase in serum magnesium and delay in calcification propensity. In addition, we observed significant decreases in both serum phosphate and intact parathyroid hormone in the high dialysate magnesium group, but no change in ionized calcium. During the trial, there occurred no adverse events attributed to the intervention.

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Why is it important?

This is the first clinical trial to demonstrate that increasing dialysate magnesium improves serum calcification propensity in patients treated with hemodialysis. These are very exciting results for the nephrology community because they identify a potentially important effect of dialysate magnesium and demonstrate the concept that calcification propensity can be therapeutically modified. Clinical trials are needed to investigate whether increasing dialysate magnesium or otherwise delaying serum calcification propensity improves the prognosis of patients with end-stage kidney disease.