Increased risk of acute pancreatitis and biliary disease observed in patients with type 2 diabetes: a retrospective cohort study.

The objective of this study was to assess the risk of acute pancreatitis in patients with type 2 diabetes compared with that in patients without diabetes. We also examined the risk of biliary disease (defined as occurrence of cholelithiasis, acute cholecystitis, or cholecystectomy), which is a major cause of pancreatitis. We conducted a retrospective cohort study using a large, geographically diverse U.S. health care claims database. Eligible patients (>or=18 years) were enrolled for at least 12 continuous months (1999-2005), with no incident events of pancreatitis or biliary disease during that 1 year baseline period. ICD-9 codes and prescription data were used to identify patients with type 2 diabetes; ICD-9 codes were also used to identify cases of pancreatitis and biliary disease. Overall, 337,067 patients with type 2 diabetes were matched on age and sex with 337,067 patients without diabetes. Incidence rates of disease and 95% CI were calculated per 100,000 person-years of exposure. The type 2 diabetic cohort had a 2.83-fold (95% CI 2.61-3.06) greater risk of pancreatitis and 1.91-fold (1.84-1.99) greater risk of biliary disease compared with the nondiabetic cohort. Relative to patients of corresponding age without diabetes, younger type 2 diabetic patients had the highest risk of pancreatitis (<45 years: incidence rate ratio [IRR] 5.26 [95% CI 4.31-6.42]; >or=45 years: 2.44 [2.23-2.66]). These data suggest that patients with type 2 diabetes may have an increased risk of acute pancreatitis and biliary disease.