Serum Magnesium and Sudden Death in European Hemodialysis Patients

Abstract

Despite suggestions that higher serum magnesium (Mg) levels are associated with improved outcome, the association with mortality in European hemodialysis (HD) patients has only scarcely been investigated. Furthermore, data on the association between serum Mg and sudden death in this patient group is limited. Therefore, we evaluated Mg in a post-hoc analysis using pooled data from the CONvective TRAnsport STudy (CONTRAST, NCT00205556), a randomized controlled trial (RCT) evaluating the survival risk in dialysis patients on hemodiafiltration (HDF) compared to HD with a mean follow-up of 3.1 years. Serum Mg was measured at baseline and 6, 12, 24 and 36 months thereafter. Cox proportional hazards models, adjusted for confounders using inverse probability weighting, were used to estimate hazard ratios (HRs) of baseline serum Mg on all-cause mortality, cardiovascular mortality, non-cardiovascular mortality and sudden death. A generalized linear mixed model was used to investigate Mg levels over time. Out of 714 randomized patients, a representative subset of 365 (51%) were analyzed in the present study. For every increase in baseline serum Mg of 0.1 mmol/L, the HR for all-cause mortality was 0.85 (95% CI 0.77–94), the HR for cardiovascular mortality 0.73 (95% CI 0.62–0.85) and for sudden death 0.76 (95% CI 0.62–0.93). These findings did not alter after extensive correction for potential confounders, including treatment modality. Importantly, no interaction was found between serum phosphate and serum Mg. Baseline serum Mg was not related to non-cardiovascular mortality. Mg decreased slightly but statistically significant over time (Δ -0.011 mmol/L/year, 95% CI -0.017 to -0.009, p = 0.03). In short, serum Mg has a strong, independent association with all-cause mortality, cardiovascular mortality and sudden death in European HD patients. Serum Mg levels decrease slightly over time.

Cardiovascular disease, mortality, and magnesium in chronic kidney disease: growing interest in magnesium-related interventions

“…This study included 515 patients, and the mortality risk decreased by 52% with a 1-mg/dL increase in serum Mg levels. Recently, similar findings have been increasingly reported in large-scale studies [33,34,[69][70][71]. Sakaguchi et al examined this relationship using the Japanese National Registry data [69].…”

“…Kurita et al also employed a restricted cubic spline analysis in 2165 Japanese patients and found a similar curve for the relationship between serum Mg levels and all-cause mortality [70]. In Europe, de Roji van Zuijdewijn et al demonstrated that lower serum Mg levels were associated with a high risk of all-cause and cardiovascular death as well as sudden death [71]. In these three studies [69][70][71], the relationship between hypomagnesemia and the mortality risk remained significant after the full adjustments.…”

“…In Europe, de Roji van Zuijdewijn et al demonstrated that lower serum Mg levels were associated with a high risk of all-cause and cardiovascular death as well as sudden death [71]. In these three studies [69][70][71], the relationship between hypomagnesemia and the mortality risk remained significant after the full adjustments. However, the findings from the USA [33,34] were different.…”

“…The relationship between serum Mg levels and mortality in CKD patients is shown in Table 2 [12,[33][34][35][69][70][71][72]. Van Laecke et al found that adjusted HR for all-cause mortality decreased by 7% with a 0.1-mg/dL (0.04 mmol/ L) increase in serum Mg levels in non-dialysis CKD patients [12].…”

Impact of Abnormal Serum Electrolyte Levels and Acid-Base Disorders on Clinical Outcomes among Maintenance Hemodialysis Patients

“…Another study found a strong and inverse association between serum magnesium and all-cause mortality, cardiovascular mortality and sudden death in European HD patients [39]. In a prospective study of Japanese HD patients who …”