Helicobacter pylori infection in two areas in Japan with different risks for gastric cancer

Abstract

Background : We evaluated the relationship between Helicobacter pylori and various factors associated with gastric cancer in two areas in Japan with different risks for mortality due to gastric cancer. Methods : A total of 250 sera from Niigata and 209 from Okinawa were used. H. pylori antibody and CagA antibody were measured by antigen-specific ELISAs. Serum gastrin and pepsinogen levels were determined by RIA. Results : Although there was no significant difference in H. pylori prevalence among the persons in Niigata (50%) and Okinawa (42%), CagA prevalence in these populations was significantly different, at 41% and 26%, respectively (OR = 1.98, 95%CI: 1.33–2.95, P < 0.01). Serum gastrin levels in Niigata were significantly lower than those in Okinawa in H. pylori-negative persons (P < 0.01). The serum pepsinogen I/II ratio in Niigata was significantly lower than that in Okinawa in H. pylori positive persons (P < 0.01), whereas there was no significant difference in H. pylori-negative persons. Among those positive for H. pylori, serum pepsinogen I/II ratio in Niigata was significantly lower than that in Okinawa in CagA-negative persons (P < 0.01), whereas no significant difference was observed in CagA-positive persons. Conclusions : These results suggest that the difference in the mortality ratio of gastric cancer between Niigata and Okinawa is mainly associated with the difference between areas in the prevalence of cagA-positive strains rather than that of H. pylori itself.