Risk of acute pancreatitis in patients with chronic inflammatory bowel disease - A Danish 16-year nationwide follow-up study

Background: There are few epidemiologic data about the risk of acute pancre atitis in chronic inflammatory bowel diseases; we therefore wanted to estim ate the risk of a first episode of acute pancreatitis in patients with Croh n's disease and ulcerative colitis in the total Danish population. Methods: The study included all patients discharged from Danish hospitals with a di agnosis of Crohn's disease or ulcerative colitis registered in the Danish N ational Registry of Patients in the period from 1977 to 1992. The first epi sode of acute pancreatitis was identified in the cohort. The observed numbe r of patients with acute pancreatitis was compared with expected numbers on the basis of age, sex, and calendar-specific incidence rates in the genera l population. Results: Overall, 15,526 patients were discharged and followe d up for 112,824 person-years. The standardized incidence ratio (SIR) for a cute pancreatitis was increased both in patients with Crohn's disease (SIR = 4.3; 95% confidence interval (CI), 2.9-6.1) and in those with ulcerative colitis (SIR = 2.1; 95% CI, 1.6-2.8). Conclusion: Patients with chronic inf lammatory bowel disease seem to be at increased risk of acute pancreatitis. Further validation and refinement of this registration-based study are nee ded.