Nutrients 2020, 12, 1264; doi:10.3390/nu12051264 www.mdpi.com/journal/nutrients Article Association between Serum Mg 2+ Concentrations and Cardiovascular Organ Damage in a Cohort of Adult Subjects Elettra Mancuso 1 , Maria Perticone 1 , Rosangela Spiga 1 , Carolina Averta 1 , Mariangela Rubino 1 , Teresa Vanessa Fiorentino 1 , Sofia Miceli 1 , Gaia Chiara Mannino 1, *, Angela Sciacqua 1 , Elena Succurro 1 , Francesco Perticone 1 , Giorgio Sesti 2 and Francesco Andreozzi 1 1 Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, 88100 Catanzaro, Italy ; elettramancuso@gmail.com (E.M.); mariaperticone@hotmail.com (M.P.); rosangela.spiga@gmail.com (R.S.); carolinaaverta90@gmail.com (C.A.); marubino83@gmail.com (M.R.); vanessa.fiorentino@unicz.it (T.V.F.); sofy.miceli@libero.it (S.M); sciacqua@unicz.it (A.S.); succurro@unicz.it (E.S.); perticone@unicz.it (F.P.); andreozzif@unicz.it (F.A.) 2 Department of Clinical and Molecular Medicine, University “Sapienza” of Rome, 00189 Rome, Italy; giorgio.sesti@uniroma1.it * Correspondence: gaiamannino@gmail.com; Tel.: +39-0961-369-4411 Received: 27 March 2020; Accepted: 25 April 2020; Published: 29 April 2020 Abstract: Magnesium (Mg 2+ ) levels are associated with insulin resistance, hypertension, atherosclerosis, and type 2 diabetes (T2DM). We evaluated the clinical utility of physiological Mg 2+ in assessing subclinical cardiovascular organ damage including increased carotid artery intima- media thickness (c-IMT) and left ventricular mass index (LVMI) in a cohort of well-characterized adult non-diabetic individuals. Age- and gender-adjusted correlations between Mg 2+ and metabolic parameters showed that Mg 2+ circulating levels were correlated negatively with body mass index (BMI), fasting glucose, and 2h-oral glucose tolerance test (OGTT) glucose. Similarly, Mg 2+ levels were significantly and negatively related to c-IMT and LVMI. A multivariate regression analysis revealed that age (β = 0.440; p < 0.0001), BMI (β = 0.225; p < 0.0001), and Mg 2+ concentration (β = −0.122; p < 0.01) were independently associated with c-IMT. Age (β = 0.244; p = 0.012), Mg 2+ (β = −0.177; p = 0.019), and diastolic blood pressure (β = 0.184; p = 0.038) were significantly associated with LVMI in women, while age (β = 0.211; p = 0.019), Mg 2+ (β = −0.171; p = 0.038) and the homeostasis model assessment index of insulin resistance (HOMA-IR) (β = −0.211; p = 0.041) were the sole variables associated with LVMI in men. In conclusion, our data support the hypothesis that the assessment of Mg 2+ as part of the initial work-up might help unravel the presence of subclinical organ damage in subjects at increased risk of cardiovascular complications. Keywords: magnesium; subclinical atherosclerosis; atherosclerosis; cardiovascular disease; carotid- intima media thickness; left ventricular mass index 1. Introduction Magnesium (Mg 2+ ), the principal intracellular divalent cation, is vital for a healthy human body and its importance has been highlighted since 1933, when Kruse et al. [1] reported the negative effects of acute Mg 2+ deficiency in rats. Serum concentrations of Mg 2+ is not routinely included as part of the automated chemistry profile and hypomagnesemia has been commonly unrecognized [2]. For this reason, Mg 2+ has been defined as the “forgotten cation” in clinical practice [3]. Indeed it is nowadays recognized that Mg 2+ plays a key role in a wide range of fundamental cellular reactions and biological processes, such as DNA synthesis, RNA expression [4], protein synthesis, and the regulation and