title: Mucosal impedance discriminates GERD from non-GERD conditions.
abstract: OBJECTIVE
  Current diagnostic tests for gastroesophageal reflux disease (GERD) are suboptimal and do not accurately and reliably measure chronicity of reflux. A minimally invasive device has been developed to assess esophageal mucosal impedance (MI) as a marker of chronic reflux. We performed a prospective longitudinal study to investigate MI patterns in patients with GERD and common nonreflux conditions, to assess MI patterns before and after treatment with proton pump inhibitors and to compare the performance of MI and wireless pH tests.
  
  
  METHODS
  We evaluated MI in 61 patients with erosive esophagitis, 81 with nonerosive but pH-abnormal GERD, 93 without GERD, 18 with achalasia, and 15 with eosinophilic esophagitis. MI was measured at the site of esophagitis and at 2, 5, and 10 cm above the squamocolumnar junction in all participants. MI was measured before and after acid suppressive therapy, and findings were compared with those from wireless pH monitoring.
  
  
  RESULTS
  MI values were signiﬁcantly lower in patients with GERD (erosive esophagitis or nonerosive but pH-abnormal GERD) or eosinophilic esophagitis than in patients without GERD or patients with achalasia (P < .001). The pattern of MI in patients with GERD differed from that in patients without GERD or patients with eosinophilic esophagitis; patients with GERD had low MI closer to the squamocolumnar junction, and values increased axially along the esophagus. These patterns normalized with acid suppressive therapy. MI patterns identified patients with esophagitis with higher levels of specificity (95%) and positive predictive values (96%) than wireless pH monitoring (64% and 40%, respectively).
  
  
  CONCLUSIONS
  Based on a prospective study using a prototype device, measurements of MI detect GERD with higher levels of specificity and positive predictive values than wireless pH monitoring. Clinical Trials.gov, Number: NCT01556919.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: Fehmi
authors.initials: F
authors.lastname: Ates
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: Elif Saritas
authors.initials: ES
authors.lastname: Yuksel
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: Tina
authors.initials: T
authors.lastname: Higginbotham
authors.affiliation: Department of Biostatistics, Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: James C
authors.initials: JC
authors.lastname: Slaughter
authors.affiliation: Sandhill Scientific Inc, Denver, Colorado.
authors.forename: Jerry
authors.initials: J
authors.lastname: Mabary
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Kavitt
authors.affiliation: Vanderbilt Voice Center, Vanderbilt Institute for Medicine & Public Health, Nashville, Tennessee.
authors.forename: C Gaelyn
authors.initials: CG
authors.lastname: Garrett
authors.affiliation: Vanderbilt Voice Center, Vanderbilt Institute for Medicine & Public Health, Nashville, Tennessee; Center for Surgical Quality and Outcomes Research, Vanderbilt Institute for Medicine & Public Health, Nashville, Tennessee.
authors.forename: David
authors.initials: D
authors.lastname: Francis
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt Medical Center, Nashville, Tennessee. Electronic address: michael.vaezi@vanderbilt.edu.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Vaezi
mesh_terms: D000328:Adult; D017097:Electric Impedance; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism; D011446:Prospective Studies
keywords: Comparative Analysis; PPI; Reflux Damage