Comparative Study of Infected Gastritis in Okinawa and Tokyo Based on the Kyoto Classification of Gastritis.

The incidence of gastric cancer in Okinawa Prefecture is the lowest in Japan, which is attributed to differences in strains of Helicobacter pylori in Okinawa and other prefectures in Japan. Our aim was to compare the endoscopic findings of H. pylori-infected gastric mucosa in Okinawa and Tokyo. Patients who underwent upper gastrointestinal endoscopy (UGI) at Northern Okinawa Medical Center (Okinawa group) and Juntendo University Hospital (Tokyo group) from April 2019 to March 2020 were included. Patients diagnosed with H. pylori-infected gastric mucosa were retrospectively compared between the Okinawa and Tokyo groups according to the Kyoto Classification of Gastritis. The numbers of subjects (Okinawa/Tokyo) were 435/352, male/female ratio was 247:188/181:171, and age was 53.3 ± 14.7/64.6 ± 14.3 (mean ± standard deviation) years. Regarding the Kyoto Classification of Gastritis, the prevalence (Okinawa/Tokyo) of the closed type of atrophic gastritis was 73%/37% (p < 0.001), diffuse redness 80%/84% (p = 0.145), mucosal swelling 46%/46% (p = 0.991), enlarged fold 26%/32% (p = 0.048), spotty redness 77%/68% (p = 0.002), sticky mucus 17%/36% (p < 0.001), and intestinal metaplasia 32%/42% (p < 0.001). Age analysis also revealed that closed-type atrophy and spotty redness were more frequent in the Okinawa group than in the Tokyo group. There may be regional differences in endoscopic findings of H. pylori-infected gastric mucosa between Okinawa and Tokyo.