Risk factors for primary sclerosing cholangitis

Liver Int. 2016 Jan;36(1):84-91. doi: 10.1111/liv.12894. Epub 2015 Aug 28.

Abstract

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.

Keywords: appendectomy; primary sclerosing cholangitis; risk factors; smoking.

MeSH terms

  • Adult
  • Appendectomy / statistics & numerical data*
  • Case-Control Studies
  • Cholangitis, Sclerosing / epidemiology*
  • Demography
  • Female
  • Humans
  • Inflammatory Bowel Diseases / epidemiology*
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Protective Factors
  • Risk Factors
  • Smoking / epidemiology*