Normal values of 24-h ambulatory intraluminal impedance combined with pH-metry in subjects eating a Mediterranean diet.

BACKGROUND AND AIMS: Multichannel intraluminal impedance combined with pH-metry is a novel technique for studying gastro-oesophageal reflux. As refluxes are particularly frequent after meals, we carried out this study in order to assess the impact of a Mediterranean diet on normal values of impedancemetry. METHODS: Twenty-five Italian healthy subjects (13 men, median age 29 years, range 22-67 years) without reflux symptoms were recruited for this study. They underwent oesophageal 24-h impedance + pH-metry. A Mediterranean diet was given to all subjects on the day of examination and its total energy intake was 9668.5 kJ (2300 kcal). RESULTS: A total of 1518 refluxes were recorded during 24 h with more upright than recumbent episodes (median 15 versus 0; p<0.01). The median total acid exposure time was 0.5% (range 0-4.2%). Acid and weakly acidic refluxes were equally reported (49% versus 51%). Weakly acidic episodes were more frequent than acid ones during 1-h postprandial periods (68% versus 32%; p<0.0001). Liquid-only and mixed refluxes reached the proximal oesophagus (15 cm above lower oesophageal sphincter) in 42.6% of cases. Median acid clearing time was longer than median bolus clearing time (28 s versus 12 s; p<0.01). CONCLUSIONS: This study provides normal values of pH-impedancemetry in Italian people eating a Mediterranean diet and are suitable for comparative pathophysiological investigations on reflux patients who have dietary habits similar to those of our country.

An evaluation of the antireflux properties of sodium alginate by means of combined multichannel intraluminal impedance and pH-metry.

BACKGROUND: Alginate-based preparations act as mechanical antireflux barrier, which can reduce both acid and non-acid reflux events and limit the proximal migration of oesophageal refluxate. AIM: To evaluate all the above features with a novel technique, multichannel electrical impedance and pH-metry. METHODS: Ten reflux patients underwent stationary impedancemetry and pH-metry after eating a refluxogenic meal. They were studied 1 h in basal conditions and 1 h after taking 10 mL of Gaviscon Advance. In both sessions, measurements were obtained in right lateral and supine decubitus. RESULTS: Alginate preparation was able to decrease significantly (P < 0.05) the number of acid reflux events and the percentage time pH < 4.0 compared with baseline. There was no effect of the drug on non-acid refluxes. Gaviscon Advance was also significantly effective (P < 0.05) in reducing the height of proximal migration of reflux events compared with baseline in both decubitus positions. CONCLUSIONS: Our findings explain how Gaviscon Advance controls acid reflux episodes, limits the proximal migration of refluxed material and thereby decreases symptoms in clinical practice.

Helicobacter pylori infection is not involved in the pathogenesis of either erosive or non-erosive gastro-oesophageal reflux disease.

BACKGROUND: The majority of reflux patients have non-erosive reflux disease. AIM: To evaluate the influence of Helicobacter pylori on oesophageal acid exposure in patients with both non-erosive and erosive reflux disease and in a group of controls. The pattern and distribution of chronic gastritis were also assessed. METHODS: One hundred and twelve consecutive patients with symptoms of gastro-oesophageal reflux disease agreed to undergo both upper gastrointestinal endoscopy and 24-h oesophageal pH-metry. Patients were grouped as H. pylori-positive or H. pylori-negative on the basis of both CLO-test and histology, and as cases with or without oesophagitis on the basis of endoscopy. The controls consisted of 19 subjects without reflux symptoms and with normal endoscopy and oesophageal pH-metry. RESULTS: H. pylori was positive in 35 patients (31%) and in six controls (31%); oesophagitis was found in 44 patients (39%) and non-erosive reflux disease in 68 (61%). The prevalence of chronic gastritis in the antrum and corpus was higher in H. pylori-positive than in H. pylori-negative patients (P < 0.001), but was more frequently mild (P < 0.001) than moderate or severe. The percentage total time the oesophageal pH < 4.0 was higher in patients than in controls (P < 0.008-0.001), but there was no difference between H. pylori-positive and H. pylori-negative patients (12.3% vs. 12%, P = 0.43) or H. pylori-positive and H. pylori-negative controls (1.07% vs. 1.47%, P = 0.19). CONCLUSIONS: H. pylori infection had the same prevalence in reflux patients and in controls. It did not affect oesophageal acid exposure, as there was no difference between H. pylori-positive and H. pylori-negative individuals. The high prevalence of mild body gastritis in H. pylori-positive patients suggests that H. pylori eradication is unlikely to lead to gastric functional recovery, which might precipitate or worsen symptoms and lesions in patients with gastro-oesophageal reflux disease.

Pathophysiological characteristics of long- and short-segment Barrett's oesophagus.

BACKGROUND: Depending on the length of the segment of columnar epithelium in the distal oesophagus, Barrett's oesophagus can be divided into long-segment and short-segment Barrett's oesophagus. This article describes the pathophysiological characteristics of both forms of Barrett's oesophagus. METHODS: Review of the literature. RESULTS: Although there is some disagreement, ours and most other studies suggest that long-segment columnar-lined oesophagus is causally linked to chronic gastro-oesophageal reflux and that this from of Barrett's oesophagus is characterized by lower oesophageal sphincter tone, reduced oesophageal contractility and increased acid reflux. Short-segment Barrett's oesophagus is also associated with acid reflux, but the degree of oesophageal acid exposure and the level of other pathophysiological alterations seem to be lower. CONCLUSION: Pathophysiological abnormalities appear to be more prominent in long-segment Barrett's oesophagus than in short-segment Barrett's oesophagus.