title: [Epidemiology and risk factors of inflammatory bowel diseases].
abstract: Inflammatory bowel diseases (IBD) are a public health problem in industrialized countries, where 1 in 1000 people are affected Most patients are young adults. The incidence of IBD has increased considerably in western countries since the second world war but is beginning to level off. On the other hand, the incidence is still rising in low-incidence areas such as Eastern Europe, Asia and developing countries. Differences in incidence rates across age, time, and geographic areas suggest that environmental factors are involved in IBD, but only cigarette smoking and appendectomy have consistently been identified as risk factors. An important role of genetic factors in IBD was first suggested by epidemiological studies showing familial aggregation of IBD and by twin studies. In 2001, the first CD susceptibility gene, NOD2/CARD15 on chromosome 16, was characterized. Other susceptibility genes have since been located. Their identification should help to understand the complex interaction between the environment and the intestinal immune system.
authors.affiliation: Registre des Maladies Inflammatoires Chroniques de l'Intestin (EPIMAD), service d'épidemiologie et de santé publique, Hôpital Calmette et service d'hépato-gastroentérologie, Hôpital Huriez, CH et U Lille, France.
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Colombel
authors.forename: Gwenola
authors.initials: G
authors.lastname: Vernier-Massouille
authors.forename: Antoine
authors.initials: A
authors.lastname: Cortot
authors.forename: Corinne
authors.initials: C
authors.lastname: Gower-Rousseau
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Salomez
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy / Q000009:adverse effects; D001208:Asia / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003093:Colitis, Ulcerative / Q000453:epidemiology; D003424:Crohn Disease / Q000453:epidemiology / Q000235:genetics; D003906:Developing Countries; D004200:Diseases in Twins / Q000235:genetics; D005060:Europe / Q000453:epidemiology; D005061:Europe, Eastern / Q000453:epidemiology; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011350:Proctocolitis / Q000235:genetics; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D014481:United States / Q000453:epidemiology