title: Pathophysiology of gastroesophageal reflux diseases in Chinese--role of transient lower esophageal sphincter relaxation and esophageal motor dysfunction.
abstract: OBJECTIVE
  Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux in the Western population. The major reflux mechanism in Chinese patients with GERD has not been studied before.
  
  
  METHODS
  Fifty-four patients with GERD and 28 controls underwent stationary baseline manometry and the 24-h ambulatory esophageal pH monitoring. TLESRs were measured before and after an 850 kcal meal in the supine position. Primary peristalsis, secondary peristalsis, and esophageal acid clearance were measured by esophageal manometry.
  
  
  RESULTS
  Total time esophageal pH </= 4 (7.3 vs 1.5, p= 0.001) was significantly higher in patients with GERD when compared to controls. Majority of acid reflux episodes was due to TLESR in both patients with GERD and controls. The frequency of TLESRs after meal was similar between patients with GERD and controls (1.0 vs 1.3/h, p= 0.34). There was no difference in the distribution of reflux mechanism between patients with GERD and controls. However, patients with GERD had a significantly lower successful primary peristalsis (59%vs 70%, p= 0.043) when compared to controls.
  
  
  CONCLUSIONS
  The frequency of TLESRs was similar between patients with GERD and controls during stationary manometry. Primary peristalsis was impaired in Chinese patients with GERD. Esophageal motor dysfunction may contribute to the pathophysiology of GERD in the Chinese population.
authors.affiliation: Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong.
authors.forename: Wai Man
authors.initials: WM
authors.lastname: Wong
authors.forename: Kam Chuen
authors.initials: KC
authors.lastname: Lai
authors.forename: Wai Mo
authors.initials: WM
authors.lastname: Hui
authors.forename: Wayne H C
authors.initials: WH
authors.lastname: Hu
authors.forename: Jia Qing
authors.initials: JQ
authors.lastname: Huang
authors.forename: Nina Y H
authors.initials: NY
authors.lastname: Wong
authors.forename: Harry H X
authors.initials: HH
authors.lastname: Xia
authors.forename: On On
authors.initials: OO
authors.lastname: Chan
authors.forename: Shiu Kum
authors.initials: SK
authors.lastname: Lam
authors.forename: Benjamin Chun Yu
authors.initials: BC
authors.lastname: Wong
mesh_terms: D044466:Asian People; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology*; D004942:Esophagitis, Peptic / Q000208:ethnology / Q000503:physiopathology; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000208:ethnology* / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009126:Muscle Relaxation; D010528:Peristalsis