Serum Magnesium and Mortality in Maintenance Hemodialysis Patients

The study aimed to investigate the potential contributing effect of serum magnesium on mortality in maintenance hemodialysis (MHD) patients.

The patients receiving regular MHD in March 2013 were involved. Baseline data including clinical data, anthropometrics and biochemical measurement were collected. After being followed for 36 months, the time of death and reason were recorded.

One hundred and thirty-five MHD patients were enrolled in the study and analyzed, with mean serum magnesium of 1.11 ± 0.15 mmol/l. The level of serum magnesium in 64 patients was normal (47.4%), and it was elevated in 71 of the 135 patients (52.6%). And none of MHD patients had hypomagnesemia. The levels of serum albumin (Alb), urea nitrogen, creatinine (Cr), uric acid and phosphorus were significantly higher, but high-sensitivity C-reactive protein (Hs-CRP) and lipoprotein A were significantly lower in hypermagnesemia group compared to the normal serum magnesium group (p < 0.05). Serum Alb, serum Cr, serum phosphorus and Hs-CRP were related factors of hypermagnesemia by multivariate logistic regression analysis (p < 0.05). During the 36 months of follow-up, 27 patients died (20.0%), of whom 55.6% died of cardiovascular (CV) events. Kaplan-Meier curves showed that cumulative incidence of CV mortality were significantly higher in the normal serum magnesium group than in the hypermagnesemia group (p = 0.027); however, there was no significant difference in all-cause mortality (p > 0.05).

Serum magnesium was elevated, which was related with nutrition and inflammation markers including serum Alb, serum Cr, serum phosphorus and Hs-CRP. Lower serum magnesium is a risk factor of CV mortality in MHD patients. Intervention studies are needed to clarify whether magnesium supplementation is beneficial for improving patient prognosis, when MHD patients had inflammatory and malnutrition.