Studies on mechanisms for enhanced clearance of low-density lipoproteins in patients with primary hypertriglyceridaemia.
Patients with primary hypertriglyceridaemia usually have increased clearance rates for plasma low-density lipoproteins (LDL). To evaluate the mechanisms for this effect, simultaneous turnover rates for autologous and normal homologous LDL were determined in 12 patients with primary hypertriglyceridaemia. On average, the autologous LDL was cleared more rapidly than the normal homologous LDL. Fractional catabolic rates (FCRs) for autologous LDL averaged 0.61 +/- 0.06 (SEM) pools d-1, whereas FCRs for homologous LDL averaged 0.49 +/- 0.04 pools d-1. In eight of the 12 patients the FCRs for 'hypertriglyceridaemic' LDL were found to be significantly higher than for normal LDL; in four others both forms of LDL were cleared at essentially the same rate. In all cases, however, both for the normal and 'hypertriglyceridaemic' LDL, clearance rates were higher than normal. Thus, besides the variability in LDL affinity for removal pathways, hypertriglyceridaemic patients appear to have an increased availability of LDL receptors for removal of circulating LDL.
Vega
G L
GL
Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas.
Grundy
S M
SM
D000368:Aged; D001055:Apolipoproteins B / Q000097:blood; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood*; D007700:Kinetics; D008055:Lipids / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011973:Receptors, LDL / Q000378:metabolism
D001055:Apolipoproteins B; D008055:Lipids; D008077:Lipoproteins, LDL; D011973:Receptors, LDL