Epidemiology of Crohn's disease in Indian migrants and the indigenous population in Leicestershire.

A retrospective, epidemiological community study of Crohn's disease was performed in Leicestershire from 1972 to 1989. The county population of 930,000 includes 93,000 South Asians. Potential cases were identified from hospital departments of pathology, endoscopy and medical records, in addition to general practitioners. There were 582 cases in Europeans and 28 in South Asians. The incidence of Crohn's disease in Europeans and South Asians has increased, particularly in Muslims. The standardized incidence in South Asians during the 1980s was 2.4/10(5)/year in Hindus, 3.4/10(5)/year in Sikhs and 5.4/10(5)/year in Muslims. The standardized incidence in Europeans has risen significantly to 4.7/10(5)/year from 3.4/10(5)/year in the 1970s (chi 2 = 8.1, p less than 0.005). In Leicester this increase can be accounted for entirely by new cases of colonic disease. All ethnic groups had a similar disease distribution. Small bowel disease was inversely associated with age, whilst colonic disease increased with age. However, the difference in age-specific incidence of Crohn's disease for different age bands at various sites was not significant. Overall, Hindus have a much lower incidence of Crohn's disease than Europeans.