Hypomagnesemia Is Associated with Increased Mortality among Peritoneal Dialysis Patients

<div><p>Objective</p><p>Hypomagnesemia has been associated with an increase in mortality among the general population as well as patients with chronic kidney disease or those on hemodialysis. However, this association has not been thoroughly studied in patients undergoing peritoneal dialysis. The aim of this study was to evaluate the association between serum magnesium concentrations and all-cause and cardiovascular mortalities in peritoneal dialysis patients.</p><p>Methods</p><p>This single-center retrospective study included 253 incident peritoneal dialysis patients enrolled between July 1, 2005 and December 31, 2014 and followed to June 30, 2015. Patient’s demographic characteristics as well as clinical and laboratory measurements were collected.</p><p>Results</p><p>Of 253 patients evaluated, 36 patients (14.2%) suffered from hypomagnesemia. During a median follow-up of 29 months (range: 4–120 months), 60 patients (23.7%) died, and 35 (58.3%) of these deaths were attributed to cardiovascular causes. Low serum magnesium was positively associated with peritoneal dialysis duration (r = 0.303, p < 0.001) as well as serum concentrations of albumin (r = 0.220, p < 0.001), triglycerides (r = 0.160, p = 0.011), potassium (r = 0.156, p = 0.013), calcium(r = 0.299, p < 0.001)and phosphate (r = 0.191, p = 0.002). Patients in the hypomagnesemia group had a lower survival rate than those in the normal magnesium groups (p < 0.001). In a multivariate Cox proportional hazards regression analysis, serum magnesium was an independent negative predictor of all-cause mortality (hazard ratio [HR] = 0.075, p = 0.011) and cardiovascular mortality (HR = 0.003, p < 0.001), especially in female patients. However, in univariate and multivariate Cox analysis, △Mg(difference between 1-year magnesium and baseline magnesium) was not an independent predictor of all-cause mortality and cardiovascular mortality.</p><p>Conclusion</p><p>Hypomagnesemia was common among peritoneal dialysis patients and was independently associated with all-cause mortality and cardiovascular mortality.</p></div

Survival curves for patients with different serum magnesium levels.

<p>Cumulative survival curves for (A) all-cause mortality and (B) cardiovascular mortality according to the category of baseline serum magnesium.</p

Patients who died from either all-cause or cardiovascular-only cause had significantly lower magnesium levels.

<p>Patients who died from either all-cause or cardiovascular-only cause had significantly lower magnesium levels.</p

Patient selection scheme.

<p>Patient selection scheme.</p

Baseline demographic and clinical characteristics of PD patients stratified by baseline serum magnesium level (t/U/x²: different variables were compared using different methods: t-value for normally distributed variables, U-value for non-normally distributed variable, x² for categorical variables).

<p>Baseline demographic and clinical characteristics of PD patients stratified by baseline serum magnesium level (t/U/x²: different variables were compared using different methods: t-value for normally distributed variables, U-value for non-normally distributed variable, x² for categorical variables).</p

Correlation analysis for variables and baseline serum magnesium concentrations.

<p>Correlation analysis for variables and baseline serum magnesium concentrations.</p

Additional file 1: of Neutrophil-lymphocyte ratio is associated with arterial stiffness in patients with peritoneal dialysis

Raw data of the study. (XLS 46 kb

Univariate and multivariate adjusted hazard ratios for all-cause and cardiovascular mortality in patients.

<p>Univariate and multivariate adjusted hazard ratios for all-cause and cardiovascular mortality in patients.</p