Increased risk of inflammatory bowel disease in women with endometriosis: a nationwide Danish cohort study

• Published in: Gut Vol. 61; no. 9; pp. 1279 - 1283
• Main Authors: Jess, Tine, Frisch, Morten, Jørgensen, Kristian Tore, Pedersen, Bo Vestergaard, Nielsen, Nete Munk
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.09.2012; BMJ Publishing Group; BMJ Publishing Group LTD
• Subjects: Adult; Aetiology; Age; Aged; Autoimmune diseases; Biological and medical sciences; Birth control; Codes; Cohort Studies; Colitis, Ulcerative - diagnosis; Colitis, Ulcerative - epidemiology; Crohn Disease - diagnosis; Crohn Disease - epidemiology; Crohn's disease; Crohns disease; Denmark - epidemiology; Emigration; Endometriosis; Endometriosis - epidemiology; epidemiology; Female; Female genital diseases; Follow-Up Studies; Gastroenterology. Liver. Pancreas. Abdomen; Gynecology. Andrology. Obstetrics; Hospitals; Humans; IBD; Immunology; Inflammatory bowel disease; Lupus; Medical sciences; Middle Aged; Multiple sclerosis; Non tumoral diseases; Other diseases. Semiology; Psoriasis; Risk Factors; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Studies; ulcerative colitis; Womens health; Young Adult; Denmark; Human; Endometriosis; Inflammatory disease; Female genital diseases; Inflammatory bowel disease; Crohn disease; Cohort study; Risk factor; Gastroenterology; Uterine diseases; Digestive diseases; Intestinal disease; Woman; Ulcerative colitis
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gutjnl-2011-301095

BackgroundAn association between endometriosis and certain autoimmune diseases has been suggested. However, the impact of endometriosis on risk of inflammatory bowel disease (IBD) remains unknown.ObjectiveTo assess the risk of Crohn's disease (CD) and ulcerative colitis (UC) in an unselected nationwide Danish cohort of women with endometriosis.DesignBy use of national registers, 37 661 women hospitalised with endometriosis during 1977–2007 were identified. The relative risk of developing IBD after an endometriosis diagnosis was calculated as observed versus expected numbers and presented as standardised incidence ratios (SIRs) with 95% CIs.ResultsWomen with endometriosis had a increased risk of IBD overall (SIR=1.5; 95% CI 1.4 to 1.7) and of UC (SIR=1.5; 95% CI 1.3 to 1.7) and CD (SIR=1.6; 95% CI 1.3 to 2.0) separately, even 20 years after a diagnosis of endometriosis (UC: SIR=1.5; 95% CI 1.1 to 2.1; CD: SIR=1.8; 95% CI 1.1 to 3.2). Restricting analyses to women with surgically verified endometriosis suggested even stronger associations (UC: SIR=1.8; 95% CI 1.4 to 2.3; CD: SIR=1.7; 95% CI 1.2 to 2.5).ConclusionThe risk of IBD in women with endometriosis was increased even in the long term, hence suggesting a genuine association between the diseases, which may either reflect common immunological features or an impact of endometriosis treatment with oral contraceptives on risk of IBD.