[Epidemiology in inflammatory bowel disease in five areas of Asturias. Spain]

The epidemiologic analysis inflammatory bowel disease (IBD) is a powerful research tool to assess the contribution of environmental factors to its etiology. IBD has been reported to have varying frequencies in different parts of the world, and there seem to be significant differences in the disease pattern and clinical course. The aim of the present study was to assess the disease pattern of IBD in Asturias (Spain).

A descriptive epidemiological population based study, retrospective (1954-1993) and prospective (1994-97), was performed to study 1018 patients found, bigger than 14 years, to have IBD, in five areas of Asturias (Spain) (461.965 inhabitants).

During the period of time studied, we diagnosed 1018 IBD [565 ulcerative colitis (55.5%), 415 (40.8%) Crohn's disease and 38(3.7%) indeterminate colitis], with 482 females (47.2%), 536 males (52.8%), and male/female: 1.11. Age at diagnosis were 39.49 +/- 1.08 (95% CI : 38.41 +/- 40.57); (UC: 43.95 +/- 1.47; CD: 33.53 +/- 1.51; IC: 38.26 +/- 5.14. p = 0.000. Age at onset previously at diagnosis for UC: 42.84 +/- 1.34; CD: 30.68 +/- 1.40; IC: 36.74 +/- 4.86 (p = 0.000). Diagnosis criteria: UC: syntomatic 97.34% (p = ns), endoscopy 96.63% (p = 0.000 pathology 90.26% (p = 0.000). CD: radiology 83.61% (p =0.000). Study level in CD: 57.57 (p = 0.0005). Family history: 8.4%. The most frequent involvement at diagnosis of UC was proctitis only, in 13.6%, 269% rectum and sigmoid 26% let colitis, 20% pancolitis, and in CD colon only, in 16.7%, 30.3% terminal ileum, 41.3% ileo-colon of the patients. This also helps to explain the differences in severity, need for surgery, and survival noted between community based studies.

We highlight the uniformity of distribution of the inflammatory bowel disease in relation to types and sex. The high frequency of familial Crohn's disease suggests a genetic predisposition. Highlighting a bigger morbilidad for the Crohn's Disease reflected in the surgical requirements, but however with smaller mortality that in ulcerative colitis.