title: Reproducibility of meal-induced transient lower oesophageal sphincter relaxations in patients with gastro-oesophageal reflux disease.
abstract: OBJECTIVE
  To calculate the number of subjects required in trials investigating drugs reducing the number of transient lower oesophageal sphincter relaxations (TLOSRs), the inter- and intra-individual variability of TLOSRs were determined, using meal ingestion as a trigger of TLOSRs and reflux.
  
  
  METHODS
  A total of 23 gastro-oesophageal reflux disease (GORD) patients with no to grade B oesophagitis and a hiatal hernia < or =3 cm underwent oesophageal manometry and pHmetry 1 h before and 3 h after ingestion of a solid meal on two separate days approximately 4 weeks apart. Reflux episodes and the underlying mechanisms and the number of TLOSRs were evaluated.
  
  
  RESULTS
  The number of TLOSRs, reflux episodes and % time with pH < 4 after meal ingestion did not differ significantly between the two sessions. The intra-individual variation of TLOSRs in the 3 h postprandial period (24.4) was smaller compared with the inter-individual variation (47.5). Transient lower oesophageal sphincter relaxations were the predominant cause of reflux accounting for 61 +/- 7 and 70 +/- 5% of the reflux episodes in visits 1 and 2, respectively.
  
  
  CONCLUSIONS
  These data for the first time provide information on the variability of TLOSRs and reflux evoked by meal ingestion, which is of crucial importance for the design and power calculations of future clinical studies evaluating the efficacy of new drugs targeting TLOSRs.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands. g.e.boeckxstaens@amc.uva.nl
authors.forename: G E
authors.initials: GE
authors.lastname: Boeckxstaens
authors.forename: D P
authors.initials: DP
authors.lastname: Hirsch
authors.forename: C B
authors.initials: CB
authors.lastname: Verkleij
authors.forename: A
authors.initials: A
authors.lastname: Lei
authors.forename: R
authors.initials: R
authors.lastname: Holman
authors.forename: A
authors.initials: A
authors.lastname: Lehmann
authors.forename: H
authors.initials: H
authors.lastname: Rydholm
mesh_terms: D000293:Adolescent; D000328:Adult; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology*; D005260:Female; D005502:Food; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged; D015203:Reproducibility of Results