Low plasma apolipoprotein E-rich high-density lipoprotein levels in patients with metabolic syndrome

Background: High-density lipoprotein (HDL) containing apolipoprotein E (apoE-rich HDL) represents a small portion of plasma HDL. We recently established a method for measuring plasma apoE-rich HDL. This study aimed to investigate the relationship between metabolic syndrome (MetS) and apoE-rich HDL levels. Methods: The apoE-rich HDL-cholesterol (HDL-C) levels and metabolic characteristics of 113 patients were analyzed. Results: The MetS group (n = 58) had significantly lower apoE-rich HDL-C and a lower apoE-rich HDL-C/HDL-C ratio (apoE-HDL (%)) compared to the non-MetS group. The prevalence of MetS was increased when apoE-HDL (%) decreased. In simple regression analyses, apoE-HDL (%) was significantly inversely correlated with visceral fat area (r_s = −0.370, P < 0.001) and plasma triglycerides (r_s = −0.447, P < 0.001) and positively correlated with low-density lipoprotein (LDL) mean particle size (r_s = 0.599, P < 0.001) and HDL mean particle size (r_s = 0.512, P < 0.001). Stepwise multiple regression analysis revealed that LDL mean particle size, a component of the atherogenic lipoprotein profile, was an independent predictor of apoE-HDL (%) (adjusted R² = 0.409). Conclusions: Plasma apoE-rich HDL levels might be a valuable indicator of MetS. These findings may help further understand HDL subfraction analysis in cardiometabolic diseases.