Reduced Mortality in Maintenance Haemodialysis Patients on High versus Low Dialysate Magnesium: A Pilot Study

Abstract

Background: Although low magnesium levels have been associated with an increased mortality in dialysis patients, they are kept low by routinely-used dialysates containing 0.50 mmol/L magnesium. Thus, we investigated the impact of a higher dialysate magnesium concentration on mortality. Methods: 25 patients on high dialysate magnesium (HDM) of 0.75 mmol/L were 1:2 matched to 50 patients on low dialysate magnesium (LDM) of 0.50 mmol/L and followed up for 3 years with regards to all-cause and cardiovascular mortality. Patients were matched according to age, gender, a modified version of the Charlson Comorbidity Index (CCI), and smoking status. Results: During the follow-up period, five patients died in the HDM and 18 patients in the LDM group. Patients in the HDM group had significantly higher ionized serum magnesium levels than matched controls (0.64 ± 0.12 mmol/L vs. 0.57 ± 0.10 mmol/L, p = 0.034). Log rank test showed no difference between treatment groups for all-cause mortality. After adjustment for age and CCI, Cox proportional hazards regression showed that HDM independently predicted a 65% risk reduction for all-cause mortality (hazard ratio 0.35, 95% confidence interval [CI]: 0.13, 0.97). Estimated 3-year probability of death from a cardiovascular event was 14.5% (95% CI: 7.9, 25.8) in the LDM group vs. 0% in the HDM group. Log rank test found a significant group difference for cardiovascular mortality (χ2 = 4.15, p = 0.042). Conclusions: Our data suggests that there might be a beneficial effect of an increased dialysate magnesium on cardiovascular mortality in chronic dialysis patients.

Magnesium supplementation: A consideration in dialysis patients

“…This effect was reversed by a dialysate containing calcium, 1.25 mmol L −1 , and Mg, 0.75 mmol L −122 , suggesting that Mg may be more important than calcium in maintaining the hemodynamic stability. Moreover, a small case‐control study suggests that a higher dialysate magnesium might offer a beneficial effect on all‐cause and cardiovascular mortality in chronic HD patients . In this recent study, a high dialysate magnesium of 0.75 mmol L −1 was associated with a significant mortality risk reduction as compared to standard dialysate magnesium of 0.5 mmol L −1 even after adjusting for well‐known mortality risks.…”

Increasing the Magnesium Concentration in Various Dialysate Solutions Differentially Modulates Oxidative Stress in a Human Monocyte Cell Line

“…Several authors propose the use of a CDF formulation with higher Mg levels than usual (0.5 mM) to solve the aforementioned problem and provide a new strategy to reduce oxidative stress induced by HD therapy [15,26,29]. In a recent retrospective case-control study, HD patients on dialysate with low-or high-Mg (0.5 and 0.75 mM, respectively) were analyzed for survival [32]. During a 3-year follow-up, 20% of the patients died in the high-Mg group vs. 36% in the low-Mg group [32].…”

“…In a recent retrospective case-control study, HD patients on dialysate with low-or high-Mg (0.5 and 0.75 mM, respectively) were analyzed for survival [32]. During a 3-year follow-up, 20% of the patients died in the high-Mg group vs. 36% in the low-Mg group [32]. These data suggest that the increased Mg concentration in the dialysate could have a beneficial effect on CVD-associated mortality in HD patients [23,28,46].…”

Hypomagnesemia is not an independent risk factor for mortality in Japanese maintenance hemodialysis patients

“…In experimental studies, magnesium inhibited vascular calcification and osteogenic differentiation in vitro [ 5 ], prevented calciprotein particle maturation, which can induce calcification in vitro [ 6 ], and bound to phosphate in the intestines, which reduced vascular calcification in rats [ 7 ]. In clinical studies, the follow-up periods used in previous large studies have been short [ 8 , 9 ]; notably, few interventional studies have been performed [ 2 , 10 ]. Clinical studies have produced inconsistent results regarding the association between Mg levels and mortality, partly because hypomagnesemia is linked to an increased frequency of co-morbidities.…”