[Esophageal motility abnormalities and their impact on esophageal acid exposure in patients with gastroesophageal reflux disease].

OBJECTIVE:To identify the characteristics of esophageal motility abnormalities in patients with gastroesophageal reflux disease (GERD) and its influence on esophageal acid exposure. METHODS:Patients with typical reflux symptoms and diagnosis of reflux esophagitis (RE) or non-erosive reflux disease (NERD), and healthy subject were enrolled in this prospective controlled study. The esophageal manometry and esophageal 26 hours pH monitoring were performed. GERD patients were divided into 3 groups according to their esophageal motility abnormalities: ① low lower esophageal sphincter pressure (LESP) group, ② ineffective esophageal motivation (IEM) group, ③ IEM and low LESP group. Esophageal acid exposure was analyzed among different groups. RESULTS:A total of 27 GERD patients (15 RE, 12 NERD) and 10 healthy subjects were enrolled in this study. The esophageal motility abnormalities in GERD patients mainly presented as the decrease of LESP and distal esophageal body pressure. The proportion of 3 kinds of esophageal motility abnormalities has significant difference between RE and NERD patients (P = 0.017). In IEM and low LESP group, all patients suffered from RE, with the total number of acid exposure, the total acid exposure time and the acid exposure time in fasting higher than those in low LESP group [98.0 (63.3, 282.8) times vs 41.0 (25.0, 82.0) times, P = 0.029; 11.7% (4.1%, 30.0%) vs 2.2% (1.4%, 9.6%), P = 0.045; 2.6% (0.9%, 4.9%) vs 0.0 (0.0, 1.2%), P = 0.015]. CONCLUSIONS:Esophageal motility abnormalities in GERD patients are characterized as low LESP and IEM in distal esophagus. The coexistence of low LESP and IEM exacerbates esophageal acid exposure, which might explain the mechanism of esophageal mucosal injury in RE patients.