Abstract 433: Liver Disease Alters HDL Metabolism and Function

Abstract

Background/Aims: High-density lipoproteins (HDLs) are important endogenous inhibitors of inflammatory responses. Dysfunctional HDL might contribute to the serious complications experienced by patients with acute and chronic liver failure, but the effect of cirrhosis on several metrics of HDL function is not understood. Methods: We measured metrics of HDL function in an explorative cross sectional study of 59 patients with compensated cirrhosis, 21 patients with acutely decompensated cirrhosis and 20 healthy controls. HDL particle size was assessed using native gel electrophoresis. HDL cholesterol efflux potential was assessed using [ 3 H]-cholesterol labeled macrophages. Paraoxonase activity was determined by photometry using phenylacetate as substrate. Nuclear factor-κB activation in monocytes and cytokines were assessed by flow cytometry. Endothelial regenerative activity was determined using an electric cell-substrate impedance sensing system. Results: Sera of cirrhotic patients showed low HDL-cholesterol levels and profoundly suppressed activities of several serum enzymes involved in HDL maturation and metabolism. Native gel electrophoresis analyses revealed that cirrhotic HDL shifts toward the larger HDL 2 subclass. We observed that (i) HDL cholesterol efflux capability, (ii) paraoxonase activity, (iii) the ability to inhibit monocyte production of pro-inflammatory cytokines and (iv) endothelial regenerative activities were significantly reduced in stable cirrhotic patients, and markedly suppressed in acutely decompensated patients. Of particular interest, HDL cholesterol efflux capacity appeared to be strongly associated with mortality of cirrhotic patients, independently of HDL cholesterol levels. Conclusion: Cirrhosis affects HDL metabolism and several metrics of HDL function. HDL cholesterol efflux capacity appears to predict 1-year mortality independent of HDL-cholesterol levels.