title: Integrated acidity and the pathophysiology of gastroesophageal reflux disease.
abstract: OBJECTIVE
  The aim of this study was to demonstrate that integrated esophageal and gastric acidity values, calculated from 24-h pH recordings, can provide more precise quantitative temporal data than the conventional pH parameters historically associated with gastroesophageal reflux disease (GERD) investigations.
  
  
  METHODS
  Esophagogastroduodenoscopy results and pH tracings from 20 GERD subjects with > or =10% esophageal acid contact time were studied. Integrated gastric and esophageal acidity were calculated from time-weighted average hydrogen ion concentrations at each second of the 24-h recording period.
  
  
  RESULTS
  Integrated esophageal acidity correlated with grade of esophagitis. Two quite distinct GERD subtypes were identified, with either a monophasic or biphasic pattern of integrated esophageal acidity. "Biphasic" subjects differed from "monophasic" subjects in terms of magnitude and pattern of integrated esophageal acidity. Although both groups had significant integrated nocturnal gastric acidity, only the biphasic GERD subjects had concomitant increases in nocturnal integrated esophageal acidity. Esophagitis grade was correlated with magnitude rather than pattern of integrated esophageal acidity, and it was possible to calculate a reflux coefficient that seems to provide an estimate of the quantitative motor disturbance present in GERD.
  
  
  CONCLUSIONS
  Integrated esophageal and gastric acidity provide quantitative measures of GERD pathophysiology and, compared to conventional pH parameters, should enhance evaluation of therapeutic interventions.
authors.affiliation: Science for Organizations, Inc., Chatham, New Jersey, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Gardner
authors.forename: S
authors.initials: S
authors.lastname: Rodriguez-Stanley
authors.forename: M
authors.initials: M
authors.lastname: Robinson
mesh_terms: D000143:Acids / Q000378:metabolism*; D000328:Adult; D002940:Circadian Rhythm; D004947:Esophagus / Q000378:metabolism; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D005764:Gastroesophageal Reflux / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged
chemical_list: D000143:Acids