Journal of neurogastroenterology and motility 22(4) 630-642 doi 10.5056/jnm16019
Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett’s esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett’s esophagus to that in healthy controls.
A total of 26 patients with histology-confirmed Barrett’s esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement.
Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pH-measurement and acid clearance test were not correlated (all P > 0.3).
More frequent swallowing and thus faster acid clearance in Barrett’s esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes.