Chylomicron remnant metabolism in familial hypercholesterolaemia studied with a stable isotope breath test.
Chylomicron remnant metabolism was studied using a stable isotope breath test in 25 patients with familial hypercholesterolaemia (FH) (10 homozygotes, 15 heterozygotes), and in 15 normolipidaemic controls. A lipid emulsion mimicking the composition of chylomicron remnants and labelled with cholesteryl (13)C-oleate was injected intravenously; (13)CO(2) was measured subsequently in breath using isotope-ratio mass spectrometry. The fractional catabolic rate (pools/h) of the emulsion, derived from a compartmental model, did not differ significantly among the groups: homozygous FH mean 0.20 (S.E.M. 0.05), heterozygous FH 0.12 (0.02), controls 0.16 (0.03). We suggest that the catabolism of chylomicron remnants from plasma is not impaired in FH and that the hepatic uptake of these particles is not dependent on functional LDL receptors.
Watts
G F
GF
University Department of Medicine, Royal Perth Hospital, University of Western Australia and Western Australian Heart Research Institute, Perth, Australia. gfwatts@cyllene.uwa.edu.au
Barrett
P H
PH
Marais
A D
AD
Dane-Stewart
C A
CA
Martins
I J
IJ
Dimmitt
S B
SB
Redgrave
T G
TG
D000328:Adult; D001944:Breath Tests; D053298:Chylomicron Remnants; D002914:Chylomicrons / Q000378:metabolism*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008055:Lipids / Q000097:blood; D013058:Mass Spectrometry; D008875:Middle Aged; D009154:Mutation; D011973:Receptors, LDL / Q000235:genetics; D012016:Reference Values
D053298:Chylomicron Remnants; D002914:Chylomicrons; D008055:Lipids; D011973:Receptors, LDL