title: Overweight is a risk factor for both erosive and non-erosive reflux disease.
abstract: BACKGROUND
  Studies have reported that the association between overweight and erosive oesophagitis is very strong, whilst seeming less consistent with non-erosive reflux disease.
  
  
  OBJECTIVE
  We have hypothesized that this difference may be due to the heterogeneity of endoscopy-negative population.
  
  
  METHODS
  We studied 81 patients with erosive oesophagitis, 48 controls and 295 endoscopy-negative patients classified by impedance-pH-testing as: (1) pH-POS (abnormal acid exposure); (2) hypersensitive oesophagus (normal acid exposure/SAP+); (3) functional heartburn (normal acid exposure/SAP-). Body mass index was also calculated.
  
  
  RESULTS
  Mean body mass index was significantly higher (p<0.05) in erosive oesophagitis than in endoscopy-negative patients as a whole and controls [27 (18-40) vs. 25 (16-48) vs. 23 (16-34)]. However, the separation of endoscopy-negative patients showed that mean body mass index was higher (p<0.05) in those with increased acid exposure time [26 (18-45)] than in hypersensitive oesophagus [24 (16-48)]. The former subgroup was similar to erosive oesophagitis, whilst the latter one to both functional heartburn [23 (16-34)] and controls (p=ns). Increased body mass index represented a risk factor for erosive oesophagitis (odds ratio 1.4; 95% confidence interval, 1.2-1.6) and non-erosive reflux disease pH-POS subgroup (odds ratio 1.35; 95% confidence interval, 1.2-1.5).
  
  
  CONCLUSIONS
  Our study shows that overweight represents an important risk factor for erosive oesophagitis and pH-POS non-erosive reflux disease and not for hypersensitive oesophagus and functional heartburn. This provides an explanation for the previously reported lesser role of this variable in non-erosive reflux disease population.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Genoa, Genoa, Italy. edoardo.savarino@unige.it
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
authors.forename: Patrizia
authors.initials: P
authors.lastname: Zentilin
authors.forename: Elisa
authors.initials: E
authors.lastname: Marabotto
authors.forename: Daria
authors.initials: D
authors.lastname: Bonfanti
authors.forename: Simona
authors.initials: S
authors.lastname: Inferrera
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Assandri
authors.forename: Giorgio
authors.initials: G
authors.lastname: Sammito
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gemignani
authors.forename: Manuele
authors.initials: M
authors.lastname: Furnari
authors.forename: Pietro
authors.initials: P
authors.lastname: Dulbecco
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savarino
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology; D050782:Esophageal pH Monitoring; D004942:Esophagitis, Peptic / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000209:etiology* / Q000503:physiopathology; D005769:Gastrointestinal Motility; D006356:Heartburn / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016015:Logistic Models; D008297:Male; D008365:Manometry; D008875:Middle Aged; D050177:Overweight / Q000150:complications*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D055815:Young Adult