Sevelamer carbonate reduces the risk of hypomagnesemia in hemodialysis-requiring end-stage renal disease patients

BACKGROUND Sevelamer has been associated with less progression of vascular calcifications. This effect could be due to a reduction in serum phosphate levels but also to other additive effects. Magnesium has been also shown to prevent vascular calcification but the effect of sevelamer on serum magnesium levels has not been thoroughly evaluated. Our aim was to analyze whether the use of sevelamer reduces the risk of hypomagnesemia in hemodialysis (HD)-requiring end-stage renal disease patients. METHODS All prevalent patients from the dialysis unit of the Hospital Italiano de Buenos Aires as of 1 June 2015 were evaluated. They were on three times per week bicarbonate/citrate-buffered HD. They were not receiving phosphate binders or magnesium-containing drugs. The average of three successive monthly magnesium serum levels was considered as the baseline magnesium concentration. Sevelamer carbonate use was retrieved from the patient's clinical records. RESULTS One hundred and fifty-one patients were included. A large proportion of individuals were on proton pump inhibitors (PPIs) (66%) and more than 50% were using sevelamer carbonate. Serum magnesium levels were significantly higher in those receiving sevelamer compared with those who did not (2.05 ± 0.3 versus 1.8 ± 0.4 mg/dL; P < 0.05). A larger proportion of individuals receiving sevelamer were among those with normal serum magnesium (P = 0.02), while among those with hypomagnesemia, a larger proportion were on PPIs. In the multivariate model including the use of PPIs, sevelamer carbonate resulted in an independent protective factor for hypomagnesemia (odds ratio: 0.44; 95% confidence interval: 0.21-0.87). CONCLUSIONS Hemodialysis patients receiving sevelamer show higher serum magnesium levels and a reduced risk of hypomagnesemia. This effect remains even after adjustment for PPI use. This effect could contribute to the still controversial superiority of sevelamer in preventing vascular calcifications.