title: Comparisons of the distribution of oesophageal acid exposure throughout the sleep period among the different gastro-oesophageal reflux disease groups.
abstract: BACKGROUND
  Nocturnal gastro-oesophageal reflux diseases (GERD) can lead to oesophageal mucosal injury and extra-oesophageal complications.
  
  
  OBJECTIVE
  To compare distribution of oesophageal acid exposure during sleep time among patients with non-erosive reflux disease and abnormal pH test (NERD-positive), erosive oesophagitis (EO) and Barrett's oesophagus (BO).
  
  
  METHODS
  Patients underwent endoscopy followed by 24-h oesophageal pH testing. Oesophageal acid exposure was assessed every 2 h of the sleep period (0-2, 2-4, 4-6 and 6-8 h). Each period of 2 h was evaluated for acid reflux parameters. All groups were matched by age, time from last meal and duration of sleep time.
  
  
  RESULTS
  Thirty-eight patients were enrolled (NERD-positive, 16; EO, 1.4; and BO, 8). All GERD groups demonstrated higher oesophageal acid exposure in the first vs. second half of the sleep period as determined by percent time pH <4 (BO: 34.7 vs.11.6, EO: 13.5 vs. 6.9, NERD-positive: 8.8 vs. 2.5, all P < 0.01). In general, patients with BO had a significantly higher distribution of oesophageal acid exposure than those with NERD-positive and EO.
  
  
  CONCLUSIONS
  Oesophageal acid exposure generally declines throughout the sleep period regardless of GERD group, but BO patients demonstrated the greatest decline during the sleep period.
authors.affiliation: The Neuro-Enteric Clinical Research Group, Department of Medicine, Section of Gastroenterology, Southern Arizona VA Health Care System and University of Arizona Health Sciences Center, Tucson, AZ, USA.
authors.forename: R
authors.initials: R
authors.lastname: Dickman
authors.forename: S
authors.initials: S
authors.lastname: Parthasarathy
authors.forename: I B
authors.initials: IB
authors.lastname: Malagon
authors.forename: P
authors.initials: P
authors.lastname: Jones
authors.forename: B
authors.initials: B
authors.lastname: Han
authors.forename: J
authors.initials: J
authors.lastname: Powers
authors.forename: R
authors.initials: R
authors.lastname: Fass
mesh_terms: D000328:Adult; D000368:Aged; D016099:Endoscopy, Gastrointestinal; D050782:Esophageal pH Monitoring / Q000295:instrumentation; D004942:Esophagitis, Peptic / Q000378:metabolism*; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000453:epidemiology / Q000378:metabolism*; D006356:Heartburn / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012890:Sleep; D013997:Time Factors