title: Air swallowing, belching, and reflux in patients with gastroesophageal reflux disease.
abstract: OBJECTIVE
  Belching and gastroesophageal reflux share a common physiological mechanism. The aim of this study was to investigate whether air swallowing leads to both belching and reflux.
  
  
  METHODS
  Esophageal impedance, pH, and pressure were measured during two 20-min recording periods in 12 controls and 12 patients with gastroesophageal reflux disease (GERD), before and after intragastric inflation of 600 mL of air. This was repeated after a meal. Subsequently, ambulatory 24-h impedance-pH measurement was performed.
  
  
  RESULTS
  During the 24-h study, patients showed a higher incidence of air swallows (287 +/- 45 vs 176 +/- 24, p < 0.05), belches (52.4 +/- 6.6 vs 32.7, p < 0.01), and acid reflux (42.3 +/- 7.6 vs 19.1 +/- 2.8, p < 0.01) than controls. After air infusion the incidence of gas reflux episodes was increased, both in patients (0.58 +/- 0.36 vs 3.50 +/- 0.61, p < 0.01) and in controls (0.75 +/- 0.67 vs 4.08 +/- 0.59, p < 0.01). In contrast, the incidence of acid and weakly acidic reflux episodes was not increased after air infusion, neither in patients (acid: 1.25 +/- 0.37 vs 1.20 +/- 0.33, weakly acidic: 1.08 +/- 0.40 vs 0.80 +/- 0.23) nor in controls (acid: 0.72 +/- 0.34 vs 0.50 +/- 0.23, weakly acidic: 0.80 +/- 0.35 vs 0.33 +/- 0.19). Air infusion increased transient lower esophageal sphincter relaxations (TLESR) frequency in patients and controls, but this was entirely because of an increase in gas reflux-associated TLESRs.
  
  
  CONCLUSIONS
  Patients with GERD swallow air more frequently and belch more frequently than healthy subjects. However, air swallowing is not the cause of their increase in reflux.
authors.affiliation: Department of Gastroenterology, Sint Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Bredenoord
authors.forename: Bas L A M
authors.initials: BL
authors.lastname: Weusten
authors.forename: Robin
authors.initials: R
authors.lastname: Timmer
authors.forename: André J P M
authors.initials: AJ
authors.lastname: Smout
mesh_terms: D000328:Adult; D000334:Aerophagy / Q000503:physiopathology*; D004884:Eructation / Q000503:physiopathology*; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D018709:Statistics, Nonparametric