title: Esophageal acid exposure in healthy adults in Taiwan: experience with pH step-up method by dual-channel pH-metry.
abstract: Esophageal acid exposure is common in normal subjects. The aim of this study was to investigate proximal and distal esophageal acid exposure in asymptomatic volunteers using dual-channel esophageal pH-metry with probe positioning by pH step-up. A total of 21 healthy subjects (9 male; mean age, 51 years) underwent 24-hour ambulatory esophageal pH recording with the pH step-up method using a two-channel pH probe, a portable digital data recorder, and computerized data analysis. All reflux episodes, episodes longer than 5 minutes, longest reflux episode, duration of acidity (pH <4), and percentage of time with acidity were analyzed. The 95th percentile for reflux parameters assessed in the distal/proximal esophagus were: total reflux episodes, 100/34; episodes greater than 5 minutes, 2.9/0; longest reflux episode, 16.6/2.95 minutes; duration of acidity, 87.95/15.5 minutes; and percentage of time with acidity, 7.0%/1.3%. Proximal and distal acid exposure were well correlated. Results showed that neither gender nor age influenced reflux parameters and that asymptomatic volunteers might experience some gastroesophageal reflux.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Buddhist Tzu Chi University School of Medicine and Medical Center, Hualien, Taiwan.
authors.forename: Chih-Hsun
authors.initials: CH
authors.lastname: Yi
authors.forename: Chien-Lin
authors.initials: CL
authors.lastname: Chen
authors.forename: Hans Hsien-Hong
authors.initials: HH
authors.lastname: Lin
authors.forename: Ming-Cheh
authors.initials: MC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D004947:Esophagus / Q000378:metabolism*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged