Citation: Gilca-Blanariu, G.-E.; Trifan, A.; Ciocoiu, M.; Popa, I.V.; Burlacu, A.; Balan, G.G.; Olteanu, A.V.; Stefanescu, G. Magnesium—A Potential Key Player in Inflammatory Bowel Diseases? Nutrients 2022, 14, 1914. https://doi.org/10.3390/ nu14091914 Academic Editors: Mario Barbagallo, Ligia J. Dominguez and Nicola Veronese Received: 31 March 2022 Accepted: 29 April 2022 Published: 3 May 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). nutrients Article Magnesium—A Potential Key Player in Inflammatory Bowel Diseases? Georgiana-Emmanuela Gilca-Blanariu 1 , Anca Trifan 1,2 , Manuela Ciocoiu 1 , Iolanda Valentina Popa 1, * , Alexandru Burlacu 1,3, * , Gheorghe G. Balan 1,2 , Andrei Vasile Olteanu 1 and Gabriela Stefanescu 1,2 1 Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; georgiana.gilca@gmail.com (G.-E.G.-B.); ancatrifan@yahoo.com (A.T.); mciocoiu2003@yahoo.com (M.C.); balan.gheo@yahoo.com (G.G.B.); olteanuandrei@yahoo.com (A.V.O.); gabriela.stefanescu@gmail.com (G.S.) 2 Department of Gastroenterology and Hepatology, “Sf. Spiridon” County Clinical Emergency Hospital, 700111 Iasi, Romania 3 Department of Interventional Cardiology, Cardiovascular Diseases Institute, 700503 Iasi, Romania * Correspondence: iolanda-valentina.g.popa@umfiasi.ro (I.V.P.); alexandru.burlacu@umfiasi.ro (A.B.) Abstract: The altered magnesium status in inflammatory bowel disease (IBD) patients may have a significant clinical imprint considering its role in cell signaling and genomic stability, as well as its involvement in IBD patients’ fatigue. Our study pioneers the investigation of magnesium hair concentration patterns in an adult population of IBD patients. The hair magnesium concen- tration in IBD patients is compared to healthy controls in order to identify correlations between the magnesium status and relevant parameters related to disease activity, psychological status, and sleep quality. We report a significantly lower hair magnesium concentration within the IBD group compared to healthy controls (95%CI: 0.006–0.062; p = 0.017) and lower levels in CD compared to UC (95%CI: -0.061–-0.002; p = 0.038). We identified a borderline statistical significance between the hair magnesium concentration and UC disease activity (95%CI; -0.679–0.008; p = 0.055) and a significantly lower magnesium concentration in patients who reported increased sleep latency (95%CI -0.65–-0.102; p = 0.011) or decreased sleep duration (95%CI -0.613–-0.041; p = 0.028). Our results advance several hypotheses with substantial clinical impact to be confirmed in future studies. Magnesium levels appear to be modified in IBD patients, which suggests it either plays a primary role in disease pathophysiology or a is result of the disease’s evolution. Magnesium could be used in predictive models for clinical/subclinical disease activity. Moreover, magnesium supplementation may improve IBD evolution and sleep quality for patients with a deficit of this mineral. However, confirmatory evidence-based studies are needed to generate specific dosing, time of supplementation, and optimum monitoring of magnesium status in IBD patients. Keywords: inflammatory bowel disease; magnesium; depression; anxiety; sleep; insomnia; sleep quality; PSQI; HADS 1. Introduction Altered nutritional status among inflammatory bowel disease (IBD) patients appears to be frequent, considering existing data, with an estimated prevalence of malnutrition reaching 65–75% among patients with Crohn’s disease (CD) [1] and 18–62% among ulcera- tive colitis (UC) patients [2,3]. Malnutrition can involve protein-calorie malnutrition and micronutrient deficiency, thereby influencing the disease’s course and leading to poorer outcomes, including prolonged hospital stay [4], complicated perioperative course, and even higher mortality [5]. There is recent evidence that magnesium contributes to regulating cellular timekeep- ing in animal cells [6], and, consequently, has a beneficial effect on maintaining normal circadian rhythm and contributes to improved quality of sleep in humans [7]. Moreover, Nutrients 2022, 14, 1914. https://doi.org/10.3390/nu14091914 https://www.mdpi.com/journal/nutrients