Risk of acute pancreatitis in type 2 diabetes and risk reduction on anti-diabetic drugs: a population-based cohort study in Taiwan.

OBJECTIVES: The objective of this study was to assess the risk of acute pancreatitis among patients with type 2 diabetes mellitus (DM) and identify the roles of co-morbidities and anti-diabetic drugs.

METHODS: From claims data of one million enrollees randomly sampled from a population covered by the Taiwan National Health Insurance, 19,518 adults with type 2 DM diagnosed between 2000 and 2005 were identified. In addition, 78,072 DM-free persons, frequency matched with sex, age, and index year for comparison were identified. Subjects were followed up until the end of 2008 or censored to ascertain incident acute pancreatitis cases and associations with co-morbidities and anti-diabetic drugs.

RESULTS: Patients with type 2 DM had 1.95-fold greater incidence of acute pancreatitis compared with non-diabetics (27.7 vs. 14.2 per 10,000 person-years), with an adjusted hazard ratio (HR) of 1.89 (95% confidence interval (CI)=1.65-2.18) based on multivariable Cox regression analysis. Additive Poisson regression analysis revealed an absolute risk increase of 14.4 per 10,000 person-years (95% CI=13.4-15.5) among type 2 DM patients. Co-morbid alcoholism, hepatitis C infection, and gallstones yielded additional risk of acute pancreatitis among type 2 DM patients (absolute risk increase ranges 86.3, 41.1, and 23.5 per 10,000 person-years, respectively). Patients taking anti-diabetic drugs had a reduced risk of acute pancreatitis, however. The adjusted HR decreased to 0.31 (95% CI=0.18-0.56) among patients who took five different anti-diabetic drugs.

CONCLUSIONS: Patients with type 2 DM are at an elevated risk of acute pancreatitis. Alcoholism, hepatitis C infection, and gallstones increase the risk further. However, anti-diabetic drugs reduce the risk as the number of drugs used increases and as the duration of treatment increases.