Urinary and plasma magnesium and risk of ischemic heart disease

Background: Previous studies on dietary magnesium and risk of ischemic heart disease (IHD) have yielded inconsistent results, in part because of a lack of direct measures of actual magnesium uptake. Urinary excretion of magnesium, an indicator of dietary magnesium uptake, might provide more consistent results. Objective: The objective was to investigate whether urinary magnesium excretion and plasma magnesium are associated with HID risk. Design: We examined 7664 adult participants free of known cardiovascular disease in the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study a prospective population-based cohort study. Urinary magnesium excretion was measured in 2 baseline 24-h urine collections. Results: Mean +/- SD urinary magnesium excretion was 4.24 +/- 1.65 mmol/24 h for men and 3.54 +/- 1.40 mmol/24 h for women. During a median follow-up of 10.5 y (IQR: 9.9-10.8 y), 462 fatal and nonfatal IHD events occurred. After multivariable adjustment, urinary magnesium excretion had a nonlinear relation with IHD risk (P-curvature = 0.01). The lowest sex-specific quintile (men: Conclusions: Low urinary magnesium excretion was independently associated with a higher risk of IHD incidence. An increased dietary intake of magnesium, particularly in those with the lowest urinary magnesium, could reduce the risk of IHD