title: Low mean impedance in 24-hour tracings and esophagitis in children: a strong connection.
abstract: Esophageal multiple intraluminal impedance baseline is an additional impedance parameter that was recently related to esophageal integrity. The aim of this study was to assess the relationship between mean esophageal impedance value and endoscopic findings in a large group of children. Children with symptoms of gastroesophageal reflux submitted to both endoscopy and impedance were included. Esophagitis was graded according to the Los Angeles classification. Mean impedance value was automatically calculated over 24-hour tracings. Data were adjusted for age through z-score transformation using percentiles normalized by the LMS (Lambda for the skew, Mu for the median, and Sigma for the generalized coefficient of variation) method. Nonparametric Mann-Whitney and Kruskal-Wallis tests, multiple, and stepwise regression were used. P-value <0.05 was considered as statistically significant. A total of 298 impedance tracings were analyzed. Endoscopic and histological esophagitis were detected in 30 and 29% patients, respectively. Median baseline z-score was significantly decreased both in proximal (P = 0.02) and distal (P = 0.01) esophagus in patients with endoscopic (but not histological) esophagitis. Patients with more severe esophagitis showed the lowest z-score. Bolus exposure index and the number of reflux episodes were the variables that were significantly associated with the baseline z-score. Impedance z-score is significantly decreased in infants and children with endoscopic esophagitis. Severity of esophagitis, bolus exposure index, and number of reflux episodes are factors influencing mean esophageal impedance.
authors.affiliation: Pediatric Department, University of Insubria, Varese, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Salvatore
authors.affiliation: Pediatric Department, University of Insubria, Varese, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Salvatoni
authors.affiliation: Pediatric Department, University of Naples Federico II, Naples, Italy.|UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Ummarino
authors.affiliation: UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Ghanma
authors.affiliation: Department of Pediatric Gastroenterology and Nutrition, Emma Children's Hospital AMC, Amsterdam, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Van der Pol
authors.affiliation: Department of Pediatric Gastroenterology and Nutrition, Emma Children's Hospital AMC, Amsterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Rongen
authors.affiliation: Pediatric Department, Spedali Civili, Brescia, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fuoti
authors.affiliation: Pediatric Department, Ospedale Sacco, Milano, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Meneghin
authors.affiliation: Department of Pediatric Gastroenterology and Nutrition, Emma Children's Hospital AMC, Amsterdam, The Netherlands.
authors.forename: M Alexander
authors.initials: MA
authors.lastname: Benninga
authors.affiliation: UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Vandenplas
mesh_terms: D002675:Child, Preschool; D017097:Electric Impedance; D050782:Esophageal pH Monitoring / Q000379:methods*; D004942:Esophagitis, Peptic / Q000175:diagnosis / Q000503:physiopathology; D004945:Esophagoscopy / Q000379:methods; D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D008297:Male; D015203:Reproducibility of Results; D013223:Statistics as Topic
keywords: children; endoscopy; esophageal impedance; z-score