Transendothelial exchange of low-density lipoprotein is unaffected by the presence of severe atherosclerosis.
OBJECTIVE
We tested the hypothesis that transendothelial exchange of low-density lipoprotein (LDL) is influenced by the presence of severe atherosclerosis; we previously found this exchange elevated in diabetes patients.


METHODS
By an in vivo isotope method, we compared transendothelial LDL exchange in 24 patients with angiographically verified coronary atherosclerosis, 11 patients with angiographically verified peripheral atherosclerosis, 60 patients with diabetes, and in 42 controls. Autologous 131-iodinated LDL ((131)I-LDL) and 125-iodinated albumin ((125)I-albumin) were injected intravenously (i.v.), and the 1-h fractional escape rates (FER(LDL) and FER(alb)) were taken as indices of transendothelial exchange.


RESULTS
Patients with coronary or peripheral atherosclerosis had FER(LDL) similar to that of controls [4.3 (3.5-5.1) and 3.2 (2.3-4.1) versus 4.2 (3.7-4.7)%/h; P>0.05], even after adjustment for LDL distribution volume (DV(LDL)). In contrast, diabetes patients had significantly higher FER(LDL) than controls [5.2 (4.6-5.7) versus 4.2 (3.7-4.7)%/h; P<0.05]. This difference was even more pronounced after correction for the distribution volume of LDL. Compared with controls, FER(alb) was not elevated in patients with coronary atherosclerosis, possibly elevated in patients with peripheral atherosclerosis, but was elevated in diabetes patients. There was a tight positive correlation between FER(LDL) and FER(alb) in all groups of patients and controls.


CONCLUSIONS
Transendothelial exchange of low-density lipoprotein is not elevated in patients having severe atherosclerosis. This suggests that the observed vascular leakiness in diabetes precedes and possibly contributes to accelerated atherosclerosis in diabetes.
Department of Nephrology and Endocrinology P, The National University Hospital, Copenhagen, Denmark.
Karen
K
Kornerup
Børge Grønne
BG
Nordestgaard
Trine Krogsgaard
TK
Jensen
Bo
B
Feldt-Rasmussen
Jonas Peter
JP
Eiberg
Kurt Svarre
KS
Jensen
Jan Skov
JS
Jensen
D001161:Arteriosclerosis / Q000378:metabolism*; D002199:Capillary Permeability; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000378:metabolism; D003920:Diabetes Mellitus / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D008077:Lipoproteins, LDL