Gastro-esophageal reflux disease: the recent trend in Japan

Gastro-esophageal reflux disease (GERD) has increased in Japan, as in other countries. This is probably due to increased acid secretion among Japanese due to Westernized foods and lifestyle as well as decreased prevalence of Helicobacter pylori infection. Proton pump inhibitor (PPI) is mainly used for treatment of this condition. PPI has recently been approved for treatment of nonerosive reflux disease (NERD) in Japan. NERD is known to have different characteristics to GERD, and effectiveness of PPI in NERD patients is lower than that in reflux esophagitis patients. Regarding therapeutic benefit of treatment, a recent study showed that PPI improved quality of life (QOL) of GERD patients also in Japan. For diagnosis of reflux esophagitis in Japan, we use a unique classification, a modified Los Angeles (LA) classification, which includes minimal change (grade M esophagitis) as one distinct criteria. However, recent studies from Japan showed poor interobserver agreement in diagnosis of grade M, although excess acid reflux in minimal change was shown in another study. Our definition of Barrett's esophagus is also different from that in the West. Nationwide consensus on diagnosis of reflux esophagitis and Barrett's esophagus should be achieved in Japan, preferably consistent with world standard.