title: Wireless oesophageal pH monitoring: establishing values in a multiracial cohort of asymptomatic Asian subjects.
abstract: BACKGROUND
  Wireless oesophageal (Bravo) readings in healthy European and American subjects show varied results. Values in Asians remain unstudied.
  
  
  OBJECTIVE
  We performed Bravo studies in healthy Asians to determine if values differed from previously published and identified reflux parameters to differentiate healthy volunteers from patients.
  
  
  METHODS
  Fifty healthy volunteers were recruited between August 2009 and August 2011 to undergo 48 h wireless pH monitoring. Bravo capsule was introduced transorally and placed 6 cm above the squamocolumnar junction. Acid reflux parameters were compared against 41 patients previously evaluated for non-erosive reflux disease.
  
  
  RESULTS
  Five volunteers were excluded. Capsule dislodgement occurred in four and three volunteers on study days 1 and 2 respectively. Forty and 37 volunteers (73% male, mean age 33.0 ± 7.6 years) had interpretable readings at 24 and 48 h, respectively. Percentage of time oesophageal pH<4 in 37 volunteers who completed 48 h recordings was 1.6% (7.5%), 1.5% (6.3%) and 1.9% (5.8%) on days 1, 2 and overall study duration, respectively.
  
  
  CONCLUSIONS
  Bravo readings in Asians differed from previously published. Percentage of time oesophageal pH<4 on day 2 and DeMeester score on day 2 (95th percentile 22.9) best discriminated healthy volunteers from patients.
authors.affiliation: Department of Gastroenterology, Changi General Hospital, Singapore. ang_daphne@yahoo.com
authors.forename: Daphne
authors.initials: D
authors.lastname: Ang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Tiing Leong
authors.initials: TL
authors.lastname: Ang
authors.forename: Ngai Moh
authors.initials: NM
authors.lastname: Law
authors.forename: Choo Hean
authors.initials: CH
authors.lastname: Poh
authors.forename: Eng Kiong
authors.initials: EK
authors.lastname: Teo
authors.forename: Kwong Ming
authors.initials: KM
authors.lastname: Fock
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D053705:Capsule Endoscopes; D015331:Cohort Studies; D050782:Esophageal pH Monitoring; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D059015:Wireless Technology; D055815:Young Adult