Background and Aims: Primary sclerosing cholangitis (PSC) is a liver disease without medical therapy that significantly increases the risk of malignancies, acute cholangitis and cirrhosis. Approximately 2-7% of patients with inflammatory bowel disease (IBD) develop PSC. No drug has been shown to prevent de novo PSC in patients with IBD. Statin use, however, has been associated with increased liver transplant-free survival. Yet, the impact of statins on development of new PSC among those with IBD is unknown. Methods: We conducted a retrospective cohort study of patients diagnosed with IBD with and without statin exposure using a large, representative national database. Patients were followed from the date of diagnosis of IBD. Patient demographics, co-morbidities, medications, and type of IBD were extracted. Unmatched and propensity score-matched Cox regression analyses were performed. Results: Our analysis included 33,813 patients with IBD of whom 8,813 were exposed to statins. PSC developed in 181 patients over a median follow-up of 3.7 years. Only nine patients (0.1%) who were exposed to statins developed PSC compared to 173 (0.69%) in the non-exposed population. In propensity score-matched analysis, statin therapy was associated with an 86% lower risk of developing PSC (HR 0.14; 95% CI 0.06-0.33, p<0.001). The findings were consistent when accounting for unmeasured confounders (E-value) in sensitivity analyses, including stratification by age group, duration of statin use, and type of statin. Conclusion: In a propensity score-matched analysis, statin use was associated with an 86% risk reduction in new PSC diagnosis among patients with known IBD, suggesting a potential benefit as a prophylactic agent. These findings warrant prospective validation.

The authors have declared no competing interest.

Support for this work came from the Paul G. Allen Frontiers Group and The Leona M. and Harry B. Helmsley Charitable Trust (Grant 2007-04026)

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was deemed exempt from review by the Institutional Review Board of Stanford University because of its use of retrospective, de-identified data.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors