title: Frequency analyses of gastric pH in control and gastro-oesophageal reflux disease subjects treated with a proton-pump inhibitor.
abstract: BACKGROUND
  We are unaware of any solid theoretical or pathophysiological basis for selecting pH 4 or any other pH value to assess gastric acidity.
  
  
  OBJECTIVE
  To examine the frequency of different gastric pH values in control and GERD subjects.
  
  
  METHODS
  Gastric pH was measured for 24 h in 26 control subjects, 26 gastro-oesophageal reflux disease subjects at baseline and the same 26 gastro-oesophageal reflux disease subjects during treatment with a proton-pump inhibitor. Histograms were constructed using the 21 600 values generated from each recording and bins of 0.25 pH units.
  
  
  RESULTS
  The distribution of gastric pH values in gastro-oesophageal reflux disease subjects was significantly different from that in controls and in some instances the distributions detected significant differences that were not detected by integrated acidity. Proton-pump inhibitor treatment significantly altered the distribution of gastric pH values and the nature of this alteration during the postprandial period was different from that during the nocturnal period. Using time pH< or =4 can significantly underestimate the magnitude of inhibition of gastric acidity caused by a proton-pump inhibitor.
  
  
  CONCLUSIONS
  The distribution of gastric pH values provides a rationale for selecting a particular pH value to assess gastric acidity. In some instances, the distribution of gastric pH values detects significant differences between gastro-oesophageal reflux disease and normal subjects that are not detected by integrated acidity.
authors.affiliation: Science for Organizations, Inc., Chatham, NJ 07928, USA. gardnerj@scifororg.com
authors.forename: J D
authors.initials: JD
authors.lastname: Gardner
authors.forename: S
authors.initials: S
authors.lastname: Sloan
authors.forename: M
authors.initials: M
authors.lastname: Robinson
authors.forename: P B
authors.initials: PB
authors.lastname: Miner
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D001562:Benzimidazoles / Q000627:therapeutic use; D002940:Circadian Rhythm; D005744:Gastric Acid / Q000502:physiology*; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019518:Postprandial Period; D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D011897:Random Allocation; D012016:Reference Values; D013270:Stomach / Q000737:chemistry*
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D009853:Omeprazole