Objective: There is limited data on cigarette smoking and the risk of acute pancreatitis (AP). We evaluated the influence of cigarette smoking on AP risk and clinical presentation in a large cohort of Veteran's Administration (VA) patients.
Methods: Retrospective study of VA patients from 1998 to 2007. Exclusion criteria included (1) history of chronic pancreatitis (n = 3222) or gallstones (n = 14,574) and (2) age younger than 15 years (n = 270). A 2-year washout period was used to exclude patients with pre-existing recurrent AP.
Results: The study included 484,624 patients. From 2001 to 2007, a total of 6799 (1.4%) patients had AP. Alcohol (risk ratio, 4.20) and smoking (risk ratio, 1.78) were independent significant risk factors of AP on multiple regression analysis. Smoking increased the risk of AP in both nonalcoholics (0.57% vs 1.1%) and alcoholics (2.6% vs 4.1%). Smoking was associated with younger mean age at first episode of AP and higher likelihood of recurrent AP (≥4 episodes) in both nonalcoholics and alcoholics. The interval between recurrent episodes was not altered by alcohol or smoking.
Conclusions: In a large cohort of VA patients, smoking is an independent risk factor for AP and augmented the effect of alcohol on the risk, age of onset, and recurrence of AP.