Comparison of oesophageal function tests between Chinese non-erosive reflux disease and reflux hypersensitivity patients

BACKGROUND By means of 24 h multi-channel intraluminal impedance and pH recording (MII/pH), patients with heartburn and normal upper gastrointestinal endoscopy findings can be classified into those with non-erosive reflux disease (NERD) and those with reflux hypersensitivity (RH). Therefore, in this study, we investigated the difference in oesophageal function tests in Chinese patients with NERD and RH. METHODS NERD patients were selected from the digestive department, Beijing Anzhen Hospital and Beijing Chao-Yang Hospital, Capital Medical University, after upper gastrointestinal endoscope, high-resolution manometry and impedance (HRiM), and MII/pH examinations between 2014 and 2016. RESULTS In total, 111 NERD patients with abnormal acid exposure, and 92 RH patients were enrolled. Values for NERD and RH were as follows: lower oesophageal sphincter pressure, 15.3 ± 8.9 and 19.3 ± 23.3 mmHg (P = 0.122); integrated relaxation pressure, 7.5 ± 4.8 and 7.9 ± 5.2 mmHg (P = 0.485); distal contractile integral, 751.9 ± 856.2 and 661.9 ± 961.7 mmHg∙s∙cm (P = 0.482); ineffective oesophageal motility rate, 49.5% and 41.3% (P = 0.241); fragmented peristalsis rate, 5.4% and 9.8% (P = 0.235); hiatal hernia rate, 9.0% and 8.6% (P = 0.938); total bolus transit time, 6.3 ± 1.3 and 6.5 ± 1.3 s (P = 0.119); complete bolus transit rate, 76.1 ± 33.0% and 73.1 ± 32.0% (P = 0.224); total acid exposure time, 6.1 ± 3.7% and 0.8 ± 0.8% (P < 0.001); total bolus exposure time, 2.5 ± 2.1% and 1.5 ± 1.1% (P < 0.001); proximal acid reflux events, 13.2 ± 10.5 and 9.7 ± 8.9 (P = 0.011); distal acid reflux events, 25.3 ± 15.8 and 13.4 ± 11.2 (P < 0.001); post-reflux swallow-induced peristaltic wave index, 25.1 ± 9.5% and 32.6 ± 15.2% (P < 0.001); and mean nocturnal baseline impedance, 1,450.2 ± 750.8 and 2,503.6 ± 964.1 ohms (P < 0.001), respectively. CONCLUSIONS NERD and RH patients showed similar values on HRiM. NERD patients had greater acid exposure time, bolus exposure time, proximal and distal acid reflux events, and increased impairment of chemical clearance and mucosal integrity than RH patients. NERD and RH should be classified correctly by MII/pH to provide adequate relief from related symptoms.