Different patterns of oesophageal acid exposure distinguish complicated reflux disease from either erosive reflux oesophagitis or non-erosive reflux disease

Background: The reason why less than one-half of patients with gastro-oesophageal reflux disease develop complicated reflux disease (ulcerative oesophagitis, oesophageal strictures and Barrett's oesophagus) and erosive reflux oesophagitis is not fully understood. Supine nocturnal oesophageal acid reflux is considered to be critically involved in this phenomenon, but reliable data are lacking. Aim: To clarify whether high levels of supine nocturnal oesophageal acid exposure are associated with complicated reflux disease. Methods: Ambulatory 24-h oesophageal pH monitoring was performed in 220 patients with gastro-oesophageal reflux disease (56 with complicated reflux disease, 76 with erosive reflux oesophagitis and 88 with non-erosive reflux disease). The total, supine nocturnal and upright diurnal percentage acid reflux times were calculated. Results: The total percentage acid reflux time was significantly greater in complicated reflux disease than in either erosive reflux oesophagitis (P = 0.024) or non-erosive reflux disease (P = 0.000). These differences were entirely due to a greater supine nocturnal percentage acid reflux time (P = 0.038 and P = 0.000, respectively), whereas no difference was observed in the upright diurnal percentage acid reflux time. Conclusions: Complicated reflux disease is characterized by high levels of supine nocturnal percentage acid reflux time. Prospective studies would be appropriate to clarify whether the normalization of this parameter is relevant to the effective management of this subset of patients with gastro-oesophageal reflux disease.