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

Nutrients. 2017 Aug 23;9(9):926. doi: 10.3390/nu9090926.


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.

Keywords: cardiovascular mortality; chronic haemodialysis; dialysate magnesium; ionized magnesium; matched patients.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Aged
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / mortality
  • Cause of Death
  • Chi-Square Distribution
  • Female
  • Hemodialysis Solutions / administration & dosage*
  • Hemodialysis Solutions / adverse effects
  • Humans
  • Kaplan-Meier Estimate
  • Longitudinal Studies
  • Magnesium / administration & dosage*
  • Magnesium / adverse effects
  • Male
  • Middle Aged
  • Pilot Projects
  • Proportional Hazards Models
  • Renal Dialysis / adverse effects
  • Renal Dialysis / methods*
  • Renal Dialysis / mortality
  • Renal Insufficiency, Chronic / complications
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / mortality
  • Renal Insufficiency, Chronic / therapy*
  • Risk Factors
  • Time Factors
  • Treatment Outcome


  • Hemodialysis Solutions
  • Magnesium