Relationship between plasma lipid concentrations and HDL subclasses.
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.


METHODS
Apo-AI contents(mg/l) of plasma HDL subclasses were determined by 2-dimensional gel electrophoresis coupled with immunodetection for apo-AI. Four hundred forty-two Chinese adults subjects aged 33 to 78 years were assigned to different groups according to the third Report of NCEP (ATP III) guidelines. The subjects were first divided into 2 groups, normal and high TG, then further classified by plasma TC, HDL-C and LDL-C concentrations. The subjects were also divided into TC desirable and TC high groups.


RESULTS
Apo-A contents of prebeta(1)-HDL were higher while HDL(2b) were lower in high TG subjects vs. the corresponding normal TG subjects according to plasma TC and LDL-C concentrations. With the increase of plasma TC concentrations, apo-AI contents of prebeta(1)-HDL were significantly higher in high TC subgroup vs. TC desirable subgroup in normal TG subjects. With the decrease of HDL-C concentrations, apo-AI contents of HDL(2b) tended to decrease in normal TG subjects. And, with the increases of LDL-C concentration, in normal TG subjects, apo-AI contents of prebeta(1)-HDL and HDL(3b) were significantly higher and those of HDL(2b) were significantly lower in very high LDL-C subgroup vs. LDL-C optimal subgroup. On the other hand, apo-AI contents of prebeta(1)-HDL and HDL(3a) were significantly higher, while HDL(2a) and HDL(2b) were significantly lower in high TG and very high TG subgroup vs. normal TG subgroup within either TC desirable or TC high subjects. In a multivariate linear regression model, TG and TC concentrations were all associated independently and positively with high prebeta(1)-HDL; however, HDL-C were inversely associated with high prebeta(1)-HDL. And TG and TC concentrations were all associated independently and negatively with low HDL(2b), but HDL-C and apo-AI were positively associated with low HDL(2b).


CONCLUSIONS
With the increase of plasma TG, TC, LDL-C or the decrease of plasma HDL-C concentrations, there was a general shift toward smaller-sized HDL, which, in turn, indicates that reverse cholesterol transport might be weakened and HDL maturation might be abnormal. Plasma TG concentration is a more important factor than TC concentration on the changes of HDL subclass distribution. Moreover, when TG is normal and HDL-C decreased, large-size HDL particles tended to decrease.
Yang
Yuye
Y
Apolipoprotein Research Unit, Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041 Sichuan, People's Republic of China.
Yan
Bingyu
B
Fu
Mingde
M
Xu
Yanhua
Y
Tian
Ying
Y
D000328:Adult; D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood; D002784:Cholesterol / Q000097:blood; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood* / Q000145:classification; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D016632:Apolipoprotein A-I; D008055:Lipids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol