ApoCIII enrichment in HDL impairs HDL-mediated cholesterol efflux capacity

Apolipoprotein CIII (apoCIII) has been reported to be tightly associated with triglyceride metabolism and the susceptibility to coronary artery disease (CAD). Besides, apoCIII has also been found to affect the anti-apoptotic effects of HDL. However, the effect of apoCIII on HDL-mediated cholesterol efflux, the crucial function of HDL, has not been reported. A hospital-based case-control study was conducted to compare the apoCIII distribution in lipoproteins between CAD patients and nonCAD controls and to explore the relationship between HDL-associated apoCIII (apoCIIIHDL) and HDL-mediated cholesterol efflux. One hundred forty CAD patients and nighty nine nonCAD controls were included. Plasma apoCIII, apoCIIIHDL and cholesterol efflux capacity was measured. The apoCIIIHDL ratio (apoCIIIHDL over plasma apoCIII) was significantly higher in CAD patients than that in control group (0.52 ± 0.24 vs. 0.43 ± 0.22, P = 0.004). Both apoCIIIHDL and apoCIIIHDL ratio were inversely correlated with cholesterol efflux capacity (r = −0.241, P = 0.0002; r = −0.318, P HDL ratio was an independent contributor to HDL-mediated cholesterol efflux capacity (standardized β = −0.325, P