Alterations of HDL subclasses in hyperlipidemia

Background: It is generally accepted that different high-density lipoprotein (HDL) subclasses have distinct but interrelated metabolic functions. HDL is known to directly influence the atherogenic process and changes in HDL subclasses distribution may be related to the incidence and prevalence of atherosclerosis. Method: The relative apolipoprotein (apo)A-I contents (% apoA-I) of plasma HDL subclasses were determined by two-dimensional gel electrophoresis coupled with immunodetection for apoA-I, in 39 hypercholesterolemic (HTC) subjects, 97 hypertriglyceridemic (HTG) subjects and 32 mixed hyperlipidemic (MHL) subjects, and 124 normolipidemic subjects. Results: The relative apoA-I contents of prebeta(1)-HDL, prebeta(2)-HDL, HDL3c, HDL3b and HDL3a significantly increased while HDL2a and HDL2b significantly decreased in hyperlipidemic subjects. In HTC subjects of hyperlipidemia, the concentrations of prebeta(1)-HDL were significantly lower and HDL2b concentrations were significantly higher than in HTG and MHL subjects. In HTG subjects, the concentrations of HDL3a were significantly higher and the concentrations of HDL2b were lower than in HTC and MHL subjects. In total hyperlipidemic subjects, plasma triglyceride (TG) concentrations showed positive correlation with prebeta(1)-HDL, prebeta(2)-HDL, HDL3b and HDL3a and negative correlation with HDL2a and HDL2b. The total cholesterol (TC) concentrations showed positive correlation with the relative apoA-I contents of prebeta(1)-HDL and HDL3b, whereas the HDL-C concentrations showed negative correlation with the relative apoA-I contents of prebeta(1)-HDL and HDL3a and positive correlation with those of HDL2a and HDL2b. The relative apoA-I contents of prebeta(1)-HDL, prebeta(2)-HDL, HDL3b, and HDL3a were positively correlated whereas those of HDL2a and HDL2b were negatively correlated with TG/HDL-C ratio. Conclusion: The particle size of HDL in hyperlipidemic subjects shifted towards smaller sizes, which, in turn, indicates that the maturation of HDL may be abnormal in hyperlipidemic subjects. (C) 2003 Elsevier Science B.V. All rights reserved.