Circadian pattern of intragastric acidity in patients with non-erosive reflux disease (NERD)

Background: Most patients with gastro-oesophageal reflux disease have non-erosive reflux disease. Proton pump inhibitors are less effective than expected in these patients, but no previous study has measured their 24-h gastric pH values. Aims: To evaluate whether there are differences in 24-h intragastric acidity between reflux patients with and without oesophagitis and controls. The influence of Helicobacter pylori on the gastric pH of reflux patients was also assessed. Methods: Sixty-three consecutive patients with gastro-oesophageal reflux disease symptoms who agreed to undergo endoscopy and 24-h pH-metry were recruited. Twenty-five (39%) had erosive oesophagitis and 38 (61%) did not. H. pylori was diagnosed by CLO test, histology and ¹³C-urea breath test. Gastric pH was also measured in 30 controls without digestive symptoms. Results: H. pylori was found in seven of the 25 (28%) patients with oesophagitis and 14 of the 38 (37%) patients with non-erosive reflux disease. Oesophageal pH-metry was abnormal in 21 of the 25 (84%) patients with oesophagitis and in 32 of the 38 (84%) patients with non-erosive reflux disease. The median gastric pH did not differ between patients with and without oesophagitis or between them and controls during the 24 h (P = 0.8) and other time intervals (P = 0.2-0.4). The gastric pH did not differ between infected and non-infected patients with oesophagitis (P = 0.2-0.4) or non-erosive reflux disease (P = 0.3-0.8). Conclusions: The circadian pattern of intragastric acidity does not differ between patients with non-erosive reflux disease and oesophagitis. Moreover, the study confirms that H. pylori infection does not affect the gastric pH in either group of reflux patients.