title: High prevalence of proximal and distal gastroesophageal reflux disease in advanced COPD.
abstract: BACKGROUND
  Gastroesophageal reflux disease (GERD) is common in a variety of chronic respiratory diseases, but little is known about GERD in the setting of COPD. The aims of this study were to determine the prevalence, presentation, and predictors of GERD based on proximal and distal esophageal pH monitoring in patients with severe COPD.
  
  
  METHODS
  Forty-one COPD patients with a mean FEV1 of 24% of predicted underwent dual-probe 24-h esophageal pH monitoring, and 1 patient underwent esophagogastroduodenoscopy.
  
  
  RESULTS
  The prevalence of GERD was 57%. Elevated distal and proximal reflux were present in 41% and 46% of patients undergoing esophageal pH studies, respectively. Fifteen percent of these patients had abnormal proximal reflux despite having normal distal probe results. Most patients with GERD were not receiving acid blockers at the time of their referral, and only one third reported heartburn and/or acid regurgitation during the pH study. Only higher body mass index was predictive of reflux on regression analysis (odds ratio, 1.2; 95% confidence interval, 1.0 to 1.5; p = 0.05).
  
  
  CONCLUSIONS
  GERD is common in advanced COPD. Patients are often asymptomatic and have a relatively high prevalence of isolated abnormal proximal reflux. Dual-probe monitoring is therefore well suited for detecting GERD in patients with advanced COPD.
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care, University of Minnesota School of Medicine, MMC 276, 420 Delaware St SE, Minneapolis, MN 55455, USA. kempa001@umn.edu
authors.forename: Robert R
authors.initials: RR
authors.lastname: Kempainen
authors.forename: Kay
authors.initials: K
authors.lastname: Savik
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Whelan
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Dunitz
authors.forename: Cynthia S
authors.initials: CS
authors.lastname: Herrington
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Billings
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012044:Regression Analysis; D012307:Risk Factors