Clinical significance of gastroesophageal reflux disease with minimal change: a multicenter prospective observational study.

Non-erosive reflux disease (NERD) is classified into grade N (no minimal change) and grade M (minimal change) based on the Los Angeles classification. However, few reports have described the clinical characteristics of grade M. This study was performed to clarify the clinical characteristics of grade M. Among 290 consecutive patients with gastroesophageal reflux disease (GERD), 45 patients with grade M, 62 patients with grade N, and 94 patients with grade A were compared with respect to clinical differences. The degree of symptom improvement after 4 weeks of proton pump inhibitor administration was also prospectively compared among the three groups. Grades N and M showed no or little difference in the patients' backgrounds (including sex and body mass index), GERD/functional dyspepsia symptom scores, life dissatisfaction (diet, sleep, work, and mood), Short Form-8 (mental component summary) scores, and symptom improvement. In contrast, significant differences were present between grades M and A as well as between grades N and A. The overall results of our study suggest that the distinction between grade M and grade N is of little clinical significance from the viewpoint of clinical characteristics.