title: Is Metabolic Syndrome Considered to Be a Risk Factor for Gastroesophageal Reflux Disease (Non-Erosive or Erosive Esophagitis)?: A Systematic Review of the Evidence.
abstract: BACKGROUND
  The incidences of both gastroesophageal reflux disease (GERD) and metabolic syndrome (MetS) have increased in recent years, and it has been suggested that there is a probable association between the two. The aim of this review is to clarify whether or not MetS is a risk factor for the incidence of GERD.
  
  
  METHODS
  We searched the PubMed, ProQuest, Ovid, Science Direct, and Google Scholar databases up to February 2015 regarding the relationship between GERD and MetS as found in observational studies. Any studies that evaluated the association between the components of MetS and GERD, as well as any studies examining the association of MetS with Barrett's esophagus or esophageal carcinoma, were excluded.
  
  
  RESULTS
  Thirteen studies met the eligibility criteria. The results of nine studies suggested that there was a higher prevalence of MetS among patients with GERD (P < 0.05) and, thus, it could be considered as an independent risk factor for the incidence of GERD. However, in the one study was not observed significant association between GERD and MetS (P = 0.71). Two studies in which the prevalence of GERD was compared between individuals with and without MetS showed a higher prevalence of GERD in patients with MetS (P < 0.05). However, this finding was not observed in a similar study conducted among female participants, which reported that the different types of MetS were not important factors with regard to the prevalence of erosive esophagitis (P = Not significant).
  
  
  CONCLUSIONS
  It can be concluded that MetS may increase the risk of GERD. Consequently, there might be potential benefits to treating the metabolic abnormalities in these patients.
authors.affiliation: Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mohammadi
authors.affiliation: Department of Nutrition, School of Nutrition and Food Sciences, Isfahan University of Medical Sciences, Isfahan, IR Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Ramezani Jolfaie
authors.affiliation: Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Rooya
authors.initials: R
authors.lastname: Alipour
authors.affiliation: Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Zarrati
keywords: Abdominal Obesity; Gastroesophageal Reflux; Insulin Resistance; Metabolic Syndrome X; Obesity