title: Metabolic syndrome and visceral obesity as risk factors for reflux oesophagitis: a cross-sectional case-control study of 7078 Koreans undergoing health check-ups.
abstract: BACKGROUND
  Obesity has been associated with reflux oesophagitis. However, the relationship between metabolic syndrome characterised by visceral obesity and reflux oesophagitis is unclear.
  
  
  OBJECTIVE
  To investigate whether metabolic syndrome or visceral obesity is a risk factor for reflux oesophagitis.
  
  
  METHODS
  A cross-sectional study of 7078 subjects undergoing upper endoscopy during health check-ups was conducted (3539 patients with reflux oesophagitis vs age- and sex-matched controls). We further analysed according to categories of visceral adipose tissue and subcutaneous adipose tissue area with 750 cases and age-, sex- and waist circumference-matched controls who underwent abdominal CT scan.
  
  
  RESULTS
  The prevalence of metabolic syndrome was higher in cases than controls (26.9% vs 18.5%, p<0.001). Multivariate analysis demonstrated that metabolic syndrome is associated with reflux oesophagitis (odds ratio (OR) = 1.42; 95% confidence interval (CI), 1.26 to 1.60). Among the individual components of metabolic syndrome, waist circumference (OR = 1.47; 95% CI, 1.30 to 1.65) and triglyceride (OR = 1.20; 95% CI, 1.05 to 1.36) independently increased the risk for reflux oesophagitis. On sub-analysis, cases showed higher mean visceral adipose tissue area (cm(2)) (136.1 (SD 57.8) vs 124.0 (SD 54.7), p<0.001) and subcutaneous adipose tissue area (cm(2)) (145.9 (SD 56.8) vs 133.5 (SD 50.7), p<0.001). However, only visceral adipose tissue area was an independent risk factor for reflux oesophagitis after adjusting for multiple confounders including smoking, alcohol, body mass index (BMI) and subcutaneous adipose tissue area (OR = 1.60; 95% CI, 1.03 to 2.48, lowest quartile vs highest quartile).
  
  
  CONCLUSIONS
  Metabolic syndrome was associated with reflux oesophagitis. Abdominal obesity, especially visceral obesity, was an important risk factor for reflux oesophagitis.
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, South Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Chung
authors.forename: D
authors.initials: D
authors.lastname: Kim
authors.forename: M J
authors.initials: MJ
authors.lastname: Park
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: H C
authors.initials: HC
authors.lastname: Jung
authors.forename: I S
authors.initials: IS
authors.lastname: Song
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging; D044466:Asian People; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004942:Esophagitis, Peptic / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011859:Radiography; D012307:Risk Factors