Association between carotid intima-media thickness and low-density lipoprotein size and susceptibility of low-density lipoprotein to oxidation in asymptomatic members of familial combined hyperlipidemia families.
OBJECTIVE
In addition to low-density lipoprotein (LDL) cholesterol, small, dense LDL particles and oxidative modification of LDL have been linked to the pathogenesis of atherosclerosis. The present study was aimed at investigating the association between carotid artery intima-media thickness (IMT) and LDL particle size and susceptibility of LDL to oxidation in vitro in asymptomatic members of familial combined hyperlipidemia (FCHL) families.


METHODS
LDL particle size, susceptibility of LDL to oxidation in vitro, and carotid IMT were measured in 148 asymptomatic FCHL family members.


RESULTS
LDL particle size and lag time for LDL oxidation were reduced in hyperlipidemic compared with normolipidemic family members. LDL particle size, serum total cholesterol, and alpha-tocopherol in LDL were independently associated with lag time for LDL oxidation in multivariate analysis. LDL particle size was associated with carotid mean IMT independently of clinical, lipid, and antioxidant variables in multivariate analysis. Although the susceptibility of LDL to oxidation in vitro was correlated with mean IMT, it did not have a significant independent contribution to variation in mean IMT in the multivariate model.


CONCLUSIONS
We conclude that LDL particle size but not susceptibility of LDL to oxidation in vitro is independently associated with carotid IMT in asymptomatic FCHL family members. These results imply that small, dense LDL as an inherent feature of FCHL is an important diagnostic indicator for coronary artery disease risk in FCHL.
Liu
Ming-Lin
ML
Department of Medicine, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland.
Ylitalo
Kati
K
Nuotio
Ilpo
I
Salonen
Riitta
R
Salonen
Jukka T
JT
Taskinen
Marja-Riitta
MR
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000032:analysis; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000097:blood* / Q000000981:diagnostic imaging*; D005260:Female; D005387:Finland; D006801:Humans; D006950:Hyperlipidemia, Familial Combined / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010084:Oxidation-Reduction; D010316:Particle Size; D011237:Predictive Value of Tests; D012306:Risk; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging; D014463:Ultrasonography
D000975:Antioxidants; D008077:Lipoproteins, LDL