title: Effect of fasting subjects' posture on 13C-urea breath test for detection of Helicobacter pylori infection.
abstract: BACKGROUND
  Although many factors that may affect the 13C-urea value have been verified, no literature is available regarding the effect of the posture of the patient on the shape of the delta 13C excretion curve. In an effort to contribute to the development of a simple and standard procedure for the 13C-urea breath test, we investigated whether either the posture of the patient during the procedure or the mouthwash after dosing affects the shape of the delta 13C excretion curve.
  
  
  METHODS
  Seventy-two Helicobacter pylori-infected subjects were divided into four groups according to the position during procedure and the mouthwash after dosing: group A, in the supine position with mouthwash; group B, in the sitting position with mouthwash; group C, changed position by rolling with mouthwash; and group D, changed position (as did group C) without mouthwash. Absolute values of delta 13C at each sampling point were compared in the four groups.
  
  
  RESULTS
  delta 13C values in group A gradually increased until the 15-minute point; those in group B were almost stable from 5 to 30 minutes, and those in group C peaked at the 5-minute point, then decreased until 30 minutes, the values becoming similar at the 20-minute point. Significant differences were seen between groups A, B, C, and D at the 5- and 10-minute points.
  
  
  CONCLUSIONS
  These results suggest that posture and mouthwash affect delta 13C value at the 5- and 10-minute points. Sampling at 20 (maybe 15 or 30) minutes for fasting patients in a sitting position is considered to be appropriate for detection of H. pylori infection in a standard two-sampling-point 13C-urea breath test.
authors.affiliation: Department of Gastroenterology, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miwa
authors.forename: T
authors.initials: T
authors.lastname: Murai
authors.forename: R
authors.initials: R
authors.lastname: Ohkura
authors.forename: M
authors.initials: M
authors.lastname: Kawabe
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Ogihara
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
authors.forename: N
authors.initials: N
authors.lastname: Sato
mesh_terms: D001944:Breath Tests; D002247:Carbon Isotopes; D005215:Fasting; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000503:physiopathology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D014508:Urea
chemical_list: D002247:Carbon Isotopes; D014508:Urea