Background: Minimal changes, such as erythema without sharp demarcation or whitish turbidity of the lower esophageal mucosa, have recently been used for endoscopic classification of nonerosive reflux disease (NERD) in Japan. This study examined the usefulness of such changes in characterizing the pathophysiology of NERD.
Methods: Physicians specializing in esophageal endoscopy performed endoscopy on 115 patients with NERD. Based on the presence or absence of minimal changes, patients were categorized as displaying NERD with minimal changes (grade M, n = 49) or with no minimal changes or mucosal breaks (grade N, n = 66). Clinical features, quality of life (QOL) scores, and ambulatory 24-h esophageal pH values were compared between groups. Ambulatory 24-h esophageal pH values were monitored in 31 patients (14 grade M and 17 grade N patients) who gave consent out of 115 patients.
Results: In ambulatory 24-h esophageal pH monitoring, 57.1% (8/14) of grade M patients had pH < 4 more than 4% of the time (abnormal acid reflux) compared with 11.8% (2/17) in the grade N group, a significant difference (P = 0.018). QOL scores did not differ significantly between grades and were significantly lower in both groups compared with the general Japanese population. No significant differences were observed in patient background between the grade M and grade N groups.
Conclusions: Frequency of abnormal acid reflux with NERD is higher in patients with minimal changes than in patients without such changes. Minimal changes are most likely attributable to gastric acid reflux.