The pattern of nocturnal and diurnal esophageal acid exposure in the pathogenesis of erosive mucosal damage

OBJECTIVES: The primary objective of the present investigation was to determine from variables obtained from 24-h esophageal pH monitoring significant discriminators between patients with and without erosive esophageal mucosal damage. METHODS: Data obtained from this study were from 24-h esophageal pH monitoring and the results of upper gastrointestinal endoscopy. Statistical methods included the use of multivariate discriminant analysis. RESULTS: The results revealed that the single best measure which discriminated patients with erosive and nonerosive esophagitis was the number of recumbent reflux episodes lasting greater than 5 min. CONCLUSIONS: We conclude from these data that 1) specific evaluation of recumbent reflux and acid exposure can add substantially to the interpretation of 24-h esophageal pH studies, particularly with regard to identifying patients at risk for the development of erosive esophagitis or other potential complications; 2) esophageal mucosal erosions are associated with an increase in percent acid contact time in both the upright and supine positions, but the pattern of reflux, particularly during the nocturnal interval in terms of the number of episodes greater than 5 min, adds significant predictive value in discriminating patients with erosive mucosal damage.