BACKGROUND: 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 Helicobacter pylori 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 H. pylori 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 H. pylori. SUMMARY: 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 H. pylori-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 H. pylori-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 H. pylori infection, low-dose-aspirin-induced GERD, and pharmacological treatment for GERD. KEY MESSAGES: The recent decrease in the rate of H. pylori infection and increase in the proportion of elderly persons might have increased the prevalence of GERD in Japan.
BACKGROUND: 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 Helicobacter pylori 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 H. pylori 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 H. pylori. SUMMARY: In Japan, more than half of GERDpatients 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 H. pylori-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 H. pylori-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 H. pyloriinfection, low-dose-aspirin-induced GERD, and pharmacological treatment for GERD. KEY MESSAGES: The recent decrease in the rate of H. pyloriinfection and increase in the proportion of elderly persons might have increased the prevalence of GERD in Japan.