Oesophageal acid exposure: higher in Barrett's oesophagus than in reflux oesophagitis

Abstract

Oesophageal acid exposure at different pH intervals between 0 and 8 in patients with Barrett's oesophagus (n = 24) was compared with that in patients with reflux oesophagitis (n = 19) by using 24-h pH monitoring. Prior to the monitoring, the position and pressure of the lower oesophageal sphincter was measured by manometry. Columnar epithelium with intestinal metaplasia and goblet cells was verified histologically in all Barrett patients and grade I—III oesophagitis in patients with reflux oesophagitis. Acid exposure (percentage of total time at pH < 4) in the Barrett group was significantly greater than in the oesophagitis group: 21.5 ± 20.0% SD vs 11.1 ± 11.7% SD (P < 0.01). The number of reflux episodes lasting longer than 5 min (representing oesophageal body clearance function) was also significantly greater in the Barrett group (8.3 ± 5.9 SD) than in the oesophagitis group (4.5 ± 4.7 SD) (P < 0.01). In the Barrett group the acid exposure time was greater at all pH intervals 0-1, 1-2, 2-3 and 3-4, (P < 0.01) but in the oesophagitis group the exposure time was greater at pH interval 5-6 (P < 0.01). There was no significant difference in exposure at pH values above 7. The mean lower oesophageal sphincter pressure was equal in both groups (11.0 vs 11.9 mmHg). In conclusion, oesophageal acid exposure was significantly greater in Barrett's oesophagus than in reflux oesophagitis, and this was associated with decreased oesophageal clearance function. In addition, the results indicated the need for special attention and perhaps higher dosages of drugs to suppress acid production in patients with Barrett's oesophagus.