title: Characteristics of symptomatic GERD in Japanese patients based on 24-h pH monitoring.
abstract: BACKGROUND
  We assessed the characteristics of symptomatic gastroesophageal reflux disease (sGERD), defined as the presence of symptoms, but no endoscopic findings of reflux esophagitis, in Japanese.
  
  
  METHODS
  Sixty-three patients were diagnosed with sGERD, and underwent 24-h esophagogastric pH monitoring (32 men; mean age, 50.5 years). Patients were classified into the following three groups : reflux group (group R), minor reflux group (group MR), and a no-reflux group (group N) by the percentage of time at pH below 4 (group R, 4.0% or more; group MR, 2.0%-3.9%; group N, 0-1.9%). Hiatal hernia was assessed based on the Anatomy-Function-Pathology (AFP) classification, and the shape of the cardia was assessed based on valve factors (V0-V3).
  
  
  RESULTS
  There were 13 patients (21%) in group R, 17 (27%) in group MR, and 33 (52%) in group N. Hiatal hernia was present in 11 patients (85%) in group R, 14 (82%) in group MR, and 22 (67%) in group N. Patients grouped according to presence of V2/V3 (chalasia) accounted for 100% of those in group R, 71% of those in group MR and 70% of those in group N. Hiatal hernia was present in 10 (91%), 10 (83%), and 6 patients (86%) who had 50 or more episodes of esophageal acid reflux per day in group R, group MR, and group N, respectively.
  
  
  CONCLUSIONS
  Reflux (percentage of time below pH 4, 4%) was seen in only about 20% of the patients with sGERD, and this percentage of patients with reflux was lower compared to the data reported from the United States and Europe. The percentage of patients who had a hiatal hernia or chalasia was high in all these groups, and this seemed to be a characteristic cause of sGERD in Japanese.
authors.affiliation: Department of Surgery, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo, 105-8461, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Omura
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kashiwagi
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yano
authors.forename: Kazuto
authors.initials: K
authors.lastname: Tsuboi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Yanaga
mesh_terms: D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000473:pathology / Q000503:physiopathology*; D006551:Hernia, Hiatal / Q000150:complications; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged