title: Obesity increases the severity of acute pancreatitis: performance of APACHE-O score and correlation with the inflammatory response.
abstract: BACKGROUND
  Obese patients appear to be at risk for complications of acute pancreatitis (AP). APACHE-O score has been suggested to improve APACHE-II accuracy in predicting severe outcome in AP.
  
  
  OBJECTIVE
  To determine if APACHE-O adds any predictive value to APACHE-II score and to test the hypothesis that obese patients are at increased risk of severe AP (SAP) because of a more intense inflammatory response to pancreatic injury.
  
  
  METHODS
  102 AP patients were prospectively studied. Using a body mass index (BMI) >30, 28% of the subjects were obese. Nineteen patients developed organ dysfunction and were classified as SAP. Receiver-operating curves for prediction of SAP were calculated using admission APACHE-II and APACHE-O scores. Binary logistic regression was performed to assess if obesity is a risk for SAP and to determine the clinical factors associated with severe disease. Serum levels of IL-6, MCP-1 and CRP as well as Ranson's scores were compared between obese and non-obese patients.
  
  
  RESULTS
  Admission APACHE-O (area under the curve AUC 0.895) and APACHE-II (AUC 0.893) showed similar accuracy in predicting severe outcome. BMI was identified as a significant risk for SAP (OR 2.8, p = 0.048) and mortality (OR 11.2, p = 0.022). CRP levels were significantly higher in obese AP patients (p = 0.0001) as well as Ranson's score (p = 0.021). IL-6 and MCP-1 levels were higher in obese patients but did not reach statistical significance.
  
  
  CONCLUSIONS
  Obesity is an independent risk for SAP. Admission APACHE-O score is not more accurate than APACHE-II. Our study results suggest that obesity increases the severity of AP by amplifying the immune response to injury.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Georgios I
authors.initials: GI
authors.lastname: Papachristou
authors.forename: Dionysios J
authors.initials: DJ
authors.lastname: Papachristou
authors.forename: Haritha
authors.initials: H
authors.lastname: Avula
authors.forename: Adam
authors.initials: A
authors.lastname: Slivka
authors.forename: David C
authors.initials: DC
authors.lastname: Whitcomb
mesh_terms: D018806:APACHE; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D018932:Chemokine CCL2 / Q000097:blood; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D010195:Pancreatitis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology*; D011379:Prognosis; D012306:Risk; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D015850:Interleukin-6; D002097:C-Reactive Protein