Pathophysiology of gastroesophageal reflux diseases in Chinese - Role of transient lower esophageal sphincter relaxation and esophageal motor dysfunction

Abstract

BACKGROUND: Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for AND AIMS: 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.