Atrophic Gastritis and Intestinal Metaplasia in Japan: Results of a Large Multicenter Study

BACKGROUND: This study evaluated the relationship between Helicobacter pylori infection, atrophic gastritis and intestinal metaplasia in Japan. MATERIALS AND METHODS: This was a multicenter study performed in 21 centers in Japan. A total of 2455 individuals were enrolled. H. pylori status was determined by validated ELISAs. Atrophic gastritis was diagnosed by histology, endoscopy with Congo Red dye scattering or the Kimura-Takemoto endoscopic classification. RESULTS: Atrophic gastritis increased from 9.4% in those less than 20 years of age to > 70% in those aged 60 or older and was strongly associated with H. pylori infection. The overall prevalence of atrophic gastritis in H. pylori infection was 82.9% (1272/1534) compared with 9.8% (90/921) among uninfected (OR = 44.8; 95% CI = 34.7-57.8). Intestinal metaplasia was present in 43.1% (542/1258) of H. pylori positive persons compared with 6.2% (51/823) among the uninfected (OR = 11.5; 95% CI = 8.5-15.5). Atrophic gastritis in H. pylori positive Japanese was very high in the younger generation (38.5% in those aged 20 or less and 58.5% in those 21-30). CONCLUSIONS: Atrophic gastritis and intestinal metaplasia were strongly associated with H. pylori and not with aging. The fall in prevalence of H. pylori in Japan has not been associated with a corresponding fall in the prevalence of atrophic gastritis among those with H. pylori infection. The high prevalence of the precursor lesion, atrophic gastritis with intestinal metaplasia, among those with H. pylori infection suggests that the risk of development of early gastric cancer will continue to remain high in Japan.