Original Contribution
The American Journal of Gastroenterology (2004) 99, 2088–2093; doi:10.1111/j.1572-0241.2004.30417.x
Pathophysiology of Gastroesophageal Reflux Diseases in Chinese—Role of Transient Lower Esophageal Sphincter Relaxation and Esophageal Motor Dysfunction
Wai Man Wong MD, FACG1, Kam Chuen Lai FRCP (UK)1, Wai Mo Hui MD1, Wayne H C Hu FRCP (UK)1, Jia Qing Huang MD1, Nina Y H Wong MD1, Harry H X Xia PhD1, On On Chan MD1, Shiu Kum Lam MD, FACG1 and Benjamin Chun Yu Wong MD, FACG1
1Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong
Correspondence: K C Lai, MD, Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong
Received 14 March 2004; Revised 0000; Accepted 20 May 2004.
Abstract
BACKGROUND AND AIMS
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.
CONCLUSION
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.
