Postprandial enrichment of remnant lipoproteins with apoC-I in healthy normolipidemic men with early asymptomatic atherosclerosis.
OBJECTIVE
Recently, we reported that exaggerated postprandial triglyceridemia in normolipidemic patients with coronary artery disease is associated with enrichment of remnant lipoproteins with apolipoprotein C-I (apoC-I). In this study, the number and composition of chylomicron remnants and very low density lipoproteins (VLDLs) were examined in 30 asymptomatic normolipidemic 50-year-old men with and without early carotid atherosclerotic lesions.


RESULTS
Intima-media thickness of the far wall of the common carotid artery was determined by B-mode ultrasound. Triglyceride-rich lipoproteins were subfractionated by density gradient ultracentrifugation and separated into VLDL and chylomicron remnant fractions by immunoaffinity chromatography. The postprandial triglyceridemia and increase in triglyceride-rich lipoprotein particle number (ie, apolipoprotein B concentrations) were not exaggerated in men with early atherosclerosis. In contrast, their large (Svedberg flotation rate 60 to 400) and small (Svedberg flotation rate 20 to 60) chylomicron remnants and VLDL were greatly enriched with apoC-I, and their small chylomicron remnants and VLDL particles were relatively enriched with cholesterol. Moreover, the number of apoC-I molecules on small chylomicron remnants was strongly associated with the degree of atherosclerosis.


CONCLUSIONS
Early asymptomatic atherosclerosis in normolipidemic men without exaggerated postprandial triglyceridemia is associated with the enrichment of postprandial chylomicron and VLDL particles with apoC-I. Therefore, it is conceivable that the apoC-I content of lipoprotein remnants may serve as an early marker of coronary artery disease risk.
Björkegren
Johan
J
Atherosclerosis Research Unit, King Gustaf V Research Institute, Karolinska Hospital, Stockholm, Sweden. johan.bjorkegren@ks.se
Silveira
Angela
A
Boquist
Susanna
S
Tang
Rong
R
Karpe
Fredrik
F
Bond
M Gene
MG
de Faire
Ulf
U
Hamsten
Anders
A
D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D053302:Apolipoprotein C-I; D001055:Apolipoproteins B / Q000097:blood; D001056:Apolipoproteins C / Q000097:blood* / Q000737:chemistry; D001161:Arteriosclerosis / Q000097:blood* / Q000175:diagnosis / Q000000981:diagnostic imaging; D015415:Biomarkers / Q000097:blood; D002340:Carotid Artery Diseases / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology; D002784:Cholesterol / Q000097:blood*; D002914:Chylomicrons / Q000097:blood; D005215:Fasting / Q000097:blood; D006801:Humans; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood* / Q000737:chemistry; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D019518:Postprandial Period; D013548:Sweden; D014280:Triglycerides / Q000097:blood* / Q000737:chemistry; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography
D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D053302:Apolipoprotein C-I; D001055:Apolipoproteins B; D001056:Apolipoproteins C; D015415:Biomarkers; D002914:Chylomicrons; D008055:Lipids; D008074:Lipoproteins; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C030087:lipoprotein triglyceride; C112017:remnant-like particle cholesterol; D002784:Cholesterol