Background: The incidence and mortality from gastric cancer is high in Japanese but extremely low in

Thailand. It is different among Asian countries. The aim of this study is to investigate the difference of peptic

ulcer disease, glandular atrophy, intestinal metaplasia and topography of chronic active gastritis between the Nepalese and Japanese population.

Materials and methods: Nepalese patients were paired with Japanese patients by age, gender and

endoscopic diagnosis in order to compare the prevalence of H. pylori infection (N=309) and the difference of

H. pylori related peptic ulcer disease (N=48). Glandular atrophy and intestinal metaplasia scores were also

compared between the Nepalese and Japanese population in H. pylori positive cases (N=152) and negative

cases (N=145) using paired cases by age, gender and endoscopic diagnosis. Paired H. pylori-positive

Nepalese and Japanese population were also used to compare the ratio of corpus gastritis to antrum gastritis (C/A ratio) (N=152).

Results: Among peptic ulcer diseases, gastric ulcer was frequent in Japanese and duodenal ulcer was

frequent in Nepalese. The prevalence of H. pylori infection in the Nepalese and Japanese population were

similar. Glandular atrophy and intestinal metaplasia scores in the H. pylori positive Japanese were

significantly higher than those of Nepalese in all positions according to triple site biopsy. Furthermore, there

were significant differences in glandular atrophy and intestinal metaplasia scores between in the H.

pylori-negative Nepalese and Japanese population except intestinal metaplasia score in the greater curvature of the upper corpus. Japanese C/A ratio was significantly higher than that of Nepalese. Corpus predominant gastritis (C/A ratio>1.00) was characteristic in the elderly Japanese. Nepalese was antrum predominant (C/A ratio<1.00) in every age group.

Conclusions. Gastric ulcer was a common disease in Japanese, in contrast duodenal ulcer was common in

Nepalese. H. pylori infected Japanese patients showed severe atrophic and metaplastic gastritis in comparison with Nepalese. These results may be associated with the high incidence of gastric cancer in Japanese. Corpus predominant gastritis was found in the elderly Japanese and antrum predominant gastritis was found in every age Nepalese