Magnesium levels have been shown to be associated with elevated blood pressure (BP), endothelial dysfunction, insulin resistance, vascular calcification, inflammation, and atherosclerosis. It was also demonstrated that patients with hypertension have increased inflammation, insulin resistance, and endothelial dysfunction. However, the relationship between magnesium, ambulatory BPs, and central hemodynamic parameters were not evaluated extensively. Serum magnesium levels, ambulatory blood pressures, augmentation index (Aix), pulse wave velocity, total peripheral resistances, and cardiac output were measured for all patients. In total, 184 essential hypertension patients were enrolled. In univariate analysis, magnesium levels were correlated with hemoglobin (r = +0.155; P = .037), albumin (r = +0.180; P = .018), pulse pressure (daytime; r = -0.170; P = .021), pulse pressure (24-hour; r = -0.156; P = .035), Aix (daytime; r = -0.223; P = .002), Aix (nighttime; r = -0.169; P = .022), and Aix (24-hour; r = -0.247; P = .001). In regression analysis, magnesium levels were independently and conversely associated with daytime Aix (P < .0001), nighttime Aix (P = .019), and 24-hour Aix (P < .0001). We suggest that magnesium levels were associated with Aix but not with total peripheral resistances, pulse wave velocity, cardiac output, and central BPs. The unique mechanisms related with magnesium and Aix but not shared by other central parameters needs to be determined. J Am Soc Hypertens 2014;8(1):28-35. (C) 2014 American Society of Hypertension. All rights reserved.