Chylomicron remnant metabolism in familial hypercholesterolaemia studied with a stable isotope breath test

Chylomicron remnant metabolism was studied using a stable isotope breath te st in 25 patients with familial hypercholesterolaemia (FH) (10 homozygotes, 15 heterozygotes), and in 15 normolipidaemic controls. A lipid emulsion mi micking the composition of chylomicron remnants and labelled with cholester yl (13)-Coleate was injected intravenously; (CO2)-C-13 was measured subsequ ently in breath using isotope-ratio mass spectrometry. The fractional catab olic rate (pools/h) of the emulsion, derived from a compartmental model, di d 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 a nd that the hepatic uptake of these particles is not dependent on functiona l LDL receptors. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved .