CHRONOLOGICAL EXTENSION OF ATROPHIC GASTRITIS AND INTESTINAL METAPLASIA IN NORMAL JAPANESE

Objectives: To investigate the prevalence of atrophic gastritis and intestinal metaplasia in relation to age and biopsy site in normal Japanese and to express these data as a function of age. Design: Five biopsies were obtained stepwise at equal intervals along each of the lesser and greater curvatures. Results: The area occupied by atrophic gastritis was not static at any stage, but expanded proximally with advancing age. It started at the antrum, extending more rapidly on the lesser than on the greater curvature. The chronological extension of intestinal metaplasia was essentially the same as that of atrophic gastritis, although the rate was far slower. Intestinal metaplasia followed the onset of atrophic gastritis with a time lag of several years. The incidence of atrophic gastritis (Y(ag)) on the lesser curvature was expressed as an exponential function of age in years (T) as Y(ag) = 100 - 153.2 exp (-0.042T) and that of intestinal metaplasia (Y(im)) as Y(im) = 100 - 191.4 exp (-0.027T). Conclusions: These estimates show that, theoretically, atrophic gastritis starts to appear on the lesser curvature in the Japanese male at the age of 10.2 years, and intestinal metaplasia at the age of 24.0 years, with a 50% incidence at 26.7 and 49.7 years, respectively. Chronological extension of both atrophic gastritis and intestinal metaplasia is considered to be an aging process, and there may be a causal relationship to Helicobacter pylori.