title: Increased intragastric pressure gradients are involved in the  occurrence of acid reflux in gastroesophageal reflux disease.
abstract: OBJECTIVE
  Increased pressure gradients across the esophagogastric junction (DeltaEGJp) play a role in gastroesophageal flow during TLESR. The aim of this study was to further explore DeltaEGJp in patients with gastroesophageal reflux disease (GERD) and controls.
  
  
  METHODS
  Twenty GERD patients were studied along with 20 control subjects. High resolution manometry and pH recording were performed 1 h before and 2 h after a liquid meal (500 ml/300 kcal). DeltaEGJp was calculated at the start of a TLESR and at 180, 60, and 10 s before TLESR.
  
  
  RESULTS
  DeltaEGJp at the start of a TLESR and at 180, 60, and 10 s before TLESR was markedly increased in GERD patients compared with that in control subjects (9.9 mmHg and 7.5 mmHg, respectively; p<0.05). Whilst intragastric pressure gradients in GERD patients were increased compared with those in controls (4.6 mmHg and 2.5 mmHg, respectively; p<0.01), intraesophageal pressure gradients were similar in both groups. Furthermore, in controls, first- and second-hour postprandial intragastric pressures were decreased compared with in fasting periods (1.9 +/- 0.4 mmHg and 2.1 +/- 0.4 mmHg versus 3.5 +/- 0.4 mmHg; p<0.05), while this was not observed in GERD patients.
  
  
  CONCLUSIONS
  In GERD patients, DeltaEGJp is greater than that in controls both before and during TLESR. This phenomenon is caused by increased intragastric pressure and might contribute to increased rates of acid reflux during TLESR in GERD patients.
authors.affiliation: Department of Gastroenterology, University Medical Center Utrecht, Utrecht, The Netherlands. rutgerfrankhuisen@gmail.com
authors.forename: Rutger
authors.initials: R
authors.lastname: Frankhuisen
authors.forename: Margot A
authors.initials: MA
authors.lastname: Van Herwaarden
authors.forename: Robert Ch
authors.initials: RCh
authors.lastname: Scheffer
authors.forename: Geoffrey S
authors.initials: GS
authors.lastname: Hebbard
authors.forename: Hein G
authors.initials: HG
authors.lastname: Gooszen
authors.forename: Melvin
authors.initials: M
authors.lastname: Samsom
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology*; D050782:Esophageal pH Monitoring; D004943:Esophagogastric Junction / Q000503:physiopathology*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D009126:Muscle Relaxation / Q000502:physiology*; D011312:Pressure; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity