Cardiovascular and All-Cause Mortality Is Affected by Serum Magnesium and Diet Pattern in a Cohort of Dialysis Patients

Background: Hypomagnesaemia is associated with an increased overall mortality in patients with chronic kidney disease on dialysis (CKD-5D). Mediterranean-style diet (MD), having a high magnesium content, can serve as a form of dietary magnesium supplementation. We examined whether there is a potential link between increased Mediterranean Diet score (MDS) and elevated serum magnesium (sMg) to assess its impact on reducing mortality risk in CKD-5D patients. Methods: In this multi-center prospective observational study, 117 CKD-5D patients (66 on hemodialysis and 51 on peritoneal dialysis) with a mean age of 62 +/- 15 years were studied for a median follow-up period of 68 months. After baseline assessment, including measurement of sMg and MDS, all patients were followed up for cardiovascular (CV) and all-cause mortality. Results: Forty deaths occurred, 58% of which were cardiovascular. Patients who were above the median value of sMg (2.2 mg/dL) had a 66% reduction in CV (crude HR, 0.34; 95% CI, 0.11-0.70), and 49% reduction in all-cause (crude HR, 0.51; 95% CI, 0.27-0.96) mortality, even after adjustment for age, malnutrition inflammation score, left ventricular mass index, peripheral vascular disease and diabetes. Similar results were obtained when sMg was analyzed as a continuous variable. sMg was associated directly with MDS (r = 0.230; p = 0.012). Conclusions: Higher sMg levels are strongly and independently associated with reduced CV and all-cause mortality in CKD-5D patients. A strong correlation exists between MDS and sMg. Elevated sMg levels, achieved through MD adherence, can significantly reduce CV mortality, implicating MD as a mediator of the association between sMg and CV mortality.