title: A systematic review on the association of serum selenium and metabolic syndrome.
abstract: BACKGROUND
  This systematic review paper aims to study the experimental and human studies on the relationship between metabolic syndrome (MetS), its component and selenium (Se) concentration.
  
  
  METHODS
  The literature was searched in PubMed, Scopus, and Google Scholar databases with no time limitation using MetS X and Se key words in medical subject heading. The related papers were selected in three phases. After quality assessment, two reviewers extracted the data, whereas the third reviewer checked their extracted data. All evidence comes from experimental and laboratory studies.
  
  
  RESULTS
  Finally, 18 articles were included. While, some studies documented that as an antioxidant agent, Se might be correlated with endothelial function, large controversy exists about the type of correlation including positive, negative, and no correlation between MetS and Se levels in body. Some of the reviewed studies were focused on antioxidant supplementation effects on MetS, results also varied in this regard.
  
  
  CONCLUSIONS
  This inconsistency could be because of diversity in study design, population, lack of special focus on Se and MetS, and finally the complex nature of MetS.
authors.affiliation: Department of Physiology, Applied Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Hasan
authors.initials: MH
authors.lastname: Tajaddini
authors.affiliation: Department of Pediatrics, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Keikha
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Razzazzadeh
authors.affiliation: Department of Pediatrics, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
keywords: Selenium; metabolic syndrome; prevention; systematic review