title: The effect of age on the key parameters in the Chicago classification: a study using high-resolution esophageal manometry in asymptomatic normal individuals.
abstract: BACKGROUND
  High-resolution manometry using the Chicago classification, which utilizes parameters including integrated relaxation pressure (IRP), distal contractile integral (DCI), and contractile front velocity (CFV), shows better diagnostic ability than previous conventional criteria. However, the current normal cut-off values for the Chicago classification are based on individuals aged 19-48 years and do not include older people. Here, we aimed to assess the normal values for the Chicago classification in individuals aged 20-67 years and compare the parameters across age groups.
  
  
  METHODS
  Fifty-four asymptomatic healthy individuals (27 male and 27 female; age range. 20-67 years) were prospectively enrolled. To evaluate the effect of age and sex on manometric profiles, we attempted to enroll equal numbers of male and female subjects for each decade. Manometry was performed in both the supine and sitting positions.
  
  
  RESULTS
  The distal latency (DL) was significantly shorter with increasing age in both measurement positions. Furthermore, IRP was significantly higher with increasing age in both positions. Spearman's ranked correlation coefficient analysis indicated that DCI and IRP in both positions were positively correlated with age.
  
  
  CONCLUSIONS
  Age affects the key parameters currently used in the Chicago classification, including IRP, DCI, and DL. Larger prospective studies with older subjects are needed to determine the age-related normal values for the Chicago classification system.
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: K W
authors.initials: KW
authors.lastname: Jung
authors.forename: H-Y
authors.initials: HY
authors.lastname: Jung
authors.forename: S-J
authors.initials: SJ
authors.lastname: Myung
authors.forename: S-O
authors.initials: SO
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: I J
authors.initials: IJ
authors.lastname: Yoon
authors.forename: S Y
authors.initials: SY
authors.lastname: Seo
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: D H
authors.initials: DH
authors.lastname: Kim
authors.forename: K D
authors.initials: KD
authors.lastname: Choi
authors.forename: H J
authors.initials: HJ
authors.lastname: Song
authors.forename: G H
authors.initials: GH
authors.lastname: Lee
authors.forename: J A
authors.initials: JA
authors.lastname: Murray
authors.forename: Y
authors.initials: Y
authors.lastname: Romero
authors.forename: J-H
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015154:Esophageal Motility Disorders / Q000145:classification / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods* / Q000592:standards*; D008875:Middle Aged; D011187:Posture; D012737:Sex Factors; D055815:Young Adult
keywords: dysphagia; esophageal manometry; high-resolution esophageal manometry