Is obesity a risk factor in acute pancreatitis? A meta-analysis

Background/aims: Obesity has been associated with a worse prognosis in acute pancreatitis. According to some authors, obesity favours the development of local complications, while according to other reports obese patients presented more frequently systemic complications. Few studies find a relationship between obesity and mortality in acute pancreatitis. We conducted a meta-analysis of several reports that evaluate the relationship between obesity and the outcome of acute pancreatitis in order to assess its prognostic role in this disease.

Methods: A MEDLINE search was conducted from 1965 to December 2002 with search terms including obesity, body mass index (BMI) and pancreatitis. A total of 12 reports were identified. Of these, only four studies included patients with mild and severe acute pancreatitis and measured obesity by BMI. The end points of the meta-analysis were the severity of acute pancreatitis, local complications, systemic complications and mortality. Obesity was defined when BMI was > or =30 kg/m2. 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: A total of 607 patients were evaluated. There was no heterogeneity for the variables severity, systemic complications, local complications and mortality among the included studies. Severe AP was significantly more frequent in obese patients (OR 2.6, 95% CI 1.5-4.6). Furthermore, those patients developed significantly more systemic (OR 2.0, 95% CI 1.1-4.6) and local complications (OR 4.3, 95% CI 2.4-7.9). Mortality in obese patients was only slightly higher (OR 1.3, 95% CI 0.5-3.6).

Conclusion: Obesity is a prognostic factor favouring the development of systemic and local complications in this disease. Therefore, it should be used routinely as part of the initial assessment of the severity of a case of acute pancreatitis.