Effect of Magnesium Supplementation on Carotid Intima-Media Thickness and Flow-Mediated Dilatation among Hemodialysis Patients: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVES: The aim of the present study was to determine the efficacy of oral magnesium (Mg) supplementation on endothelial function through evaluation of carotid intima-media thickness (cIMT), brachial artery flow-mediated dilatation (FMD), and C-reactive protein (CRP) among hemodialysis (HD) patients. METHODS: This randomized, controlled, double-blind clinical trial consisted of 54 patients on HD. One group was treated orally with 440 mg of Mg oxide 3 times per week for 6 months (n = 29). The control group (n = 25) was given placebo using the same administration protocol. cIMT, FMD, serum calcium levels, phosphorus, lipid, CRP, and bicarbonate were measured at baseline and at 6 months in both groups. RESULTS: At 6 months, cIMT was significantly decreased in the Mg group (0.84 ± 0.13 mm at baseline and 0.76 ± 0.13 mm at 6 months, p = 0.001). However, in the placebo group, cIMT was significantly increased (0.73 ± 0.13 and 0.79 ± 0.12 mm, respectively, p = 0.003). When hypertension, diabetes mellitus, smoking, hyperlipidemia, and systemic lupus erythematosus were controlled for in the analysis, the effect of Mg remained significant in both groups (p = 0.000). CONCLUSION: Our results indicate that Mg might not improve endothelial function (CRP level and FMD) and that a decreased cIMT as a marker of atherosclerosis may be due to the inhibition of calcification through the regulation parathormone, calcium, and phosphorus.