Smoking as a cofactor for causation of chronic pancreatitis: a meta-analysis.

OBJECTIVES: To assess the evidence for tobacco smoking as a risk factor for the causation of chronic pancreatitis. METHODS: We performed a meta-analysis with random-effects models to estimate pooled relative risks (RRs) of chronic pancreatitis for current, former, and ever smokers, in comparison to never smokers. We also performed dose-response, heterogeneity, publication bias, and sensitivity analyses. RESULTS: Ten case-control studies and 2 cohort studies that evaluated, overall, 1705 patients with chronic pancreatitis satisfied the inclusion criteria. When contrasted to never smokers, the pooled risk estimates for current smokers was 2.8 (95% confidence interval [CI], 1.8-4.2) overall and 2.5 (95% CI, 1.3-4.6) when data were adjusted for alcohol consumption. A dose-response effect of tobacco use on the risk was ascertained: the RR for subjects smoking less than 1 pack per day was 2.4 (95% CI, 0.9-6.6) and increased to 3.3 (95% CI, 1.4-7.9) in those smoking 1 or more packs per day. The risk diminished significantly after smoking cessation, as the RR estimate for former smokers dropped to a value of 1.4 (95% CI, 1.1-1.9). CONCLUSIONS: Tobacco smoking may enhance the risk of developing chronic pancreatitis. Recommendation for smoking cessation, besides alcohol abstinence, should be incorporated in the management of patients with chronic pancreatitis