Role of human lipocalin proteins in abdominal obesity after acute pancreatitis

- Abdominal obesity is significantly associated with circulating lipocalin-2.
- Alcohol contributes to 20% of the variance in lipocalin-2.
- Abdominal obesity is not associated with circulating retinol-binding protein-4.

Lipocalin proteins are small regulatory peptides implicated in metabolism, inflammation, and immunity. Although lipocalin proteins have been linked to various clinical conditions, their role in the acute inflammatory setting, such as acute pancreatitis (AP), has only been sparsely investigated. Two members of the lipocalin family, lipocalin-2 (LCN-2) and retinol binding protein −4 (RBP-4), play an important role in obesity and insulin resistance. In this study, we analysed circulating levels of LCN-2 and RBP-4 in 92 individuals after AP, of whom 41 individuals had abdominal obesity and 51 did not. Binary logistic regression analyses were performed to determine whether abdominal obesity was associated with the two lipocalin proteins. Lipocalin-2 was significantly associated with abdominal obesity in the unadjusted model (Odds ratio (OR) = 1.014 [95% confidence interval (CI): 1.000, 1.028], P = 0.05) and after adjusting for patient related (age, ethnicity, and diabetes mellitus) and pancreatitis related (aetiology, severity, recurrence, and duration of AP) characteristics (OR = 1.018 [95% CI: 1.001, 1.036], p = 0.04). Further, the association of LCN-2 with waist circumference was significant in individuals with alcohol aetiology of AP (β=1.082 [95% CI: 1.011, 1.158], p = 0.02]. The association between RBP-4 and abdominal obesity was not significant in both unadjusted and adjusted models. These findings indicate that circulating levels of LCN-2 in patients after AP may play a role in chronic low grade inflammation associated with abdominal adiposity and that alcohol consumption may further exacerbate adipose tissue dysfunction.