Risk factors for primary sclerosing cholangitis

• Published in: Liver international Vol. 36; no. 1; pp. 84 - 91
• Main Authors: Boonstra, Kirsten, de Vries, Elisabeth M. G., van Geloven, Nan, van Erpecum, Karel J., Spanier, Marcel, Poen, Alexander C., van Nieuwkerk, Carin M., Witteman, Ben J., Tuynman, Hans A., Naber, Anton H., Kingma, Paul J., Beuers, Ulrich, Ponsioen, Cyriel Y.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.01.2016
• Subjects: Adult; appendectomy; Appendectomy - statistics & numerical data; Case-Control Studies; Cholangitis, Sclerosing - epidemiology; Demography; Female; Humans; Inflammatory Bowel Diseases - epidemiology; Male; Middle Aged; Netherlands - epidemiology; primary sclerosing cholangitis; Protective Factors; Risk Factors; smoking; Smoking - epidemiology; risk factors; appendectomy; primary sclerosing cholangitis; smoking
• ISSN: 1478-3223; 1478-3231
• DOI: 10.1111/liv.12894

Background & Aims Primary sclerosing cholangitis (PSC) is a progressive cholestatic liver disease of unknown cause, but strongly associated with inflammatory bowel disease (IBD). Potential risk factors triggering PSC have never been studied on a population level. The aim of this study was to evaluate smoking, appendectomy, family history and geographical distribution in a population‐based cohort of PSC patients, as compared to IBD control patients and healthy controls (HC). Methods For this case–control study 343 PSC patients, 370 IBD controls and 232 HC's living in a geographically defined area in the Netherlands filled‐out a questionnaire concerning smoking, appendectomy and family history of IBD and autoimmune liver diseases. Results Smoking was associated with a lower risk of developing PSC in PSC‐ulcerative colitis (UC) patients (adjusted OR 0.21; 95% CI 0.12–0.34; P < 0.001). Comparable results were found for PSC‐Crohn's disease (CD) patients (16% former smokers) compared to CD patients (55% former smokers) (adjusted OR 0.17; 95% CI 0.08–0.39; P < 0.001). Frequency of appendectomy did not differ between PSC and HC, but PSC‐UC patients had undergone appendectomy more often than UC patients (13% vs. 6%) (adjusted OR 2.51; 95%CI 1.04–6.07; P = 0.041). We found no association between family history of IBD or autoimmune liver disease and risk of PSC. Degree of urbanization was not associated with PSC incidence. Conclusion In this large population‐based case–control study we confirm that smoking is associated with a lower risk of developing PSC, independent of its protective effect for developing UC. Appendectomy is not associated with the risk of developing PSC.