Gastroesophageal Reflux Disease in Time Covering Eradication for All Patients Infected with <b><i>Helicobacter pylori</i></b> in Japan

<b><i>Background:</i></b> The prevalence of gastroesophageal reflux disease (GERD) has increased in Japan since the end of the 20th century due to changes in environmental factors, such as a decreased infection rate of <i>Helicobacter pylori</i> and increased ability of acid secretion in the Japanese population. In 2013, the Japanese health insurance system started to cover eradication treatment for all patients infected with <i>H. pylori</i> to prevent gastric cancer, suggesting we may soon be able to completely eradicate this infection in Japan. Re-clarification of the clinical characteristics of GERD in Japan is therefore required in time covering the eradication for all patients infected with <i>H. pylori</i>. <b><i>Summary:</i></b> In Japan, more than half of GERD patients exhibit non-erosive reflux disease, and a majority of erosive esophagitis (RE) cases have mild severity of GERD (Los Angeles classification of grades A and B). The prevalence of RE in <i>H. pylori</i>-positive patients is relatively low (4.1%) compared to the general Japanese population (7.6-10.6%). In multivariate analysis to evaluate a risk of RE development, a risk in <i>H. pylori</i>-positive patients is elevated in those with mild gastric mucosal atrophy (C-I and C-II according to the Kimura-Takemoto classification, OR 12.14, 95% CI 1.28-115.26, p = 0.03) or with hiatal hernia (OR 5.24, 95% CI 1.80-15.22, p < 0.01). Here, we provide a comprehensive review of GERD in Japan, including associations between GERD and <i>H. pylori</i> infection, low-dose-aspirin-induced GERD, and pharmacological treatment for GERD. <b><i>Key Messages:</i></b> The recent decrease in the rate of <i>H. pylori</i> infection and increase in the proportion of elderly persons might have increased the prevalence of GERD in Japan.