CROHNS-DISEASE IN CHINESE PEOPLE IN VANCOUVER, BRITISH-COLUMBIA

The clinical records of 21 Chinese patients with Crohn's disease seen in Vancouver, British Columbia from 1975 to 1989 were reviewed. There was a predominance of males, with a male to female ratio of 1.6:1. The age range at diagnosis was 15 to 59 years (mean 33.3). All but two of the patients were immigrants. The age at diagnosis of the two Canadian-born patients was distinctly younger (15 and 21 years old) than the mean age at diagnosis of the immigrant group. The immigrant Chinese patients had resided in Canada from four months to 16 years (mean 6.9 years) prior to the onset of symptoms. Despite the extreme rarity of Crohn's disease in Hong Kong, 62% of the patients in this series were Hong Kong immigrants. This report indicates that Crohn's disease occurs in patients of Chinese extraction more commonly than currently is appreciated and that adequate time apparently is required for exposure to environmental factors in the pathogenesis of Crohn's disease. The continued study of migrating populations, especially from low risk areas to high risk areas of the world, should further define the role of environmental factors in significantly influencing the risk of developing Crohn's disease.