Early inflammatory response in acute pancreatitis is little affected by body mass index

Obesity is a known risk factor for severe acute pancreatitis (AP), but the mechanism by which it affects the severity of AP is not fully understood. The main objective of this study was to investigate the relationship between obesity and inflammatory markers in AP.

Thirty patients with AP who developed organ failure (Group I) and 87 patients with AP who survived without organ failure (Group II) were studied. Patients' height and weight were measured at admission for calculation of body mass index (BMI). Blood samples were taken at admission for measurement of plasma interleukin (IL)-1beta, IL-6, IL-10, IL-1 receptor antagonist, procalcitonin, C-reactive protein (CRP) and monocyte human leucocyte antigen (HLA)-DR expression.

Group I patients had higher BMI values (median 26.2 kg/m2) than Group II patients (25.2 kg/m2), p =0.033. Both CRP values and monocyte HLA-DR expression showed a significant correlation with BMI (Spearman's rank correlation r=0.32, p =0.003 and r= -0.33, p = 0.002, respectively). The correlation between BMI and monocyte HLA-DR expression was significant in Group II patients (r = -0.34, p =0.002) but not in Group I patients (r = -0.02, p >0.05). There was no correlation between BMI and IL-1beta, IL-6, IL-10, IL-1 receptor antagonist or procalcitonin.

BMI did not affect either proinflammatory or anti-inflammatory cytokine levels in early AP. However, in patients with mild AP, BMI correlated positively with CRP levels and inversely with monocyte HLA-DR expression, which might reflect an amplified inflammatory response in these patients. Taken together, acute inflammatory response in AP, which ultimately determines the severity of AP, was little affected by BMI.