Obesity Is a Definitive Risk Factor of Severity and Mortality in Acute Pancreatitis: An Updated Meta-Analysis

Background/Aims: Obesity is considered a risk factor in patients with acute pancreatitis. However, the relationship between obesity and mortality in this disease has not been confirmed definitively even in a previous meta-analysis. Since the publication of our previous meta-analysis, one study has been reported about the prognostic value of obesity in acute pancreatitis. We have performed a new meta-analysis to confirm the relationship between obesity and the outcome of acute pancreatitis. Data Sources: A MEDLINE search using ‘pancreatitis’, ‘obesity’ and ‘body mass index’ as search terms. Review Methods: Clinical studies which investigated the prognostic value of obesity in acute pancreatitis with the following criteria: (a) inclusion of mild and severe acute pancreatitis; (b) use of body mass index (BMI) as the measure of obesity; (c) definition of obesity as BMI ≧30 kg/m2; (d) definition of severity of acute pancreatitis according to the criteria established in the Atlanta Symposium. Five studies including patients with mild and severe acute pancreatitis and obesity measured by BMI were analyzed. The end points of the meta-analysis were the severity of acute pancreatitis, local complications, systemic complications and mortality. Pooled odds ratio (OR) and confidence intervals (CI) were calculated according to the Mantel-Haenszel method, and heterogeneity was assessed by the multiplicative inverse variance method. Results: Seven hundred and thirty-nine patients were included. There was no heterogeneity for the variables severity, systemic complications, local complications and mortality among the included studies. Severe acute pancreatitis was significantly more frequent in obese patients (OR 2.9, 95% CI 1.8–4.6). Furthermore, those patients developed significantly more systemic (OR 2.3, 95% CI 1.4–3.8) and especially local complications (OR 3.8, 95% CI 2.4–6.6). In this new analysis, mortality was also higher in obese patients (OR 2.1, 95% CI 1.0–4.8). Conclusion: Obesity is not only a risk factor for the development of local and systemic complications in acute pancreatitis: it also increases the mortality of this disease.