title: Gastro-oesophageal reflux associated with nocturnal gastric acid breakthrough on proton pump inhibitors.
abstract: BACKGROUND
  Nocturnal gastric acid breakthrough, defined as intragastric pH < 4 for more than 1 h in the overnight period, is observed in up to 70% of normal subjects on proton pump inhibitors taken twice daily. The frequency of this breakthrough in patients with gastro-oesophageal reflux and accompanying oesophageal reflux during this period has not been studied.
  
  
  OBJECTIVE
  To examine the frequency of nocturnal break-through and accompanying oesophageal acid exposure in patients with gastro-oesophageal reflux treated with proton pump inhibitors twice daily.
  
  
  METHODS
  Prolonged ambulatory pH records from 76 patients on twice daily proton pump inhibitors between January 1991 and July 1997 were analysed for the presence of nocturnal gastric acid breakthrough and accompanying oesophageal pH < 4. Studies from 31 normal subjects on twice daily proton pump inhibitors constituted the control group.
  
  
  RESULTS
  Nocturnal gastric acid breakthrough was seen in 70% of 61 patients with gastro-oesophageal reflux, 80% of 15 patients with Barrett's oesophagus and 67% of normal controls (P=N.S.). Oesophageal acid exposure was seen in 33% of gastro-oesophageal reflux patients, 50% of Barrett's oesophagus patients and 8% of normal controls (P < 0.03). No difference was found between patients taking omeprazole or lansoprazole.
  
  
  CONCLUSIONS
  Nocturnal acid breakthrough is frequently seen on proton pump inhibitors twice daily and is often accompanied by oesophageal reflux. This has important implications for medical therapy in patients with severe gastro-oesophageal reflux and Barrett's oesophagus.
authors.affiliation: Department of Medicine, Allegheny University Hospitals, Graduate, Philadelphia, Pennsylvania, USA.
authors.forename: P O
authors.initials: PO
authors.lastname: Katz
authors.forename: C
authors.initials: C
authors.lastname: Anderson
authors.forename: R
authors.initials: R
authors.lastname: Khoury
authors.forename: D O
authors.initials: DO
authors.lastname: Castell
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D064747:Lansoprazole; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D054328:Proton Pump Inhibitors; D017494:Proton Pumps / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D054328:Proton Pump Inhibitors; D017494:Proton Pumps; D064747:Lansoprazole; D009853:Omeprazole