Lecithin: Cholesterol acyl transfer rate and high density lipoprotein level in coronary artery disease

Abstract

The lecithin:cholesterol acyl transfer (LCAT) reaction occurs in connection with the high density lipoproteins (HDL) and might have importance for the development of atheromatosis. The LCAT rate and the lipoprotein concentrations in plasma were therefore determined in 82 patients, 40–60 years old, with incapacitating angina pectoris and significant lesions at coronary angiography. Thirty-eight cases were normolipidemic and 22 had type IV hyperlipidemia while the others had different types of hypercholesterolemia (n = 7) or were pharmacologically treated for previously diagnosed hyperlipidemia (n = 11) or diabetes mellitus. The normolipidemic group and the type IV group with coronary artery disease were separately compared to one normolipidemic (n = 44) and one type IV hyperlipidemic (n = 29) control group of healthy subjects of about the same age. The fractional LCAT rate (% · h −1) was lower in patients compared to controls both regarding the normolipidemic and type IV subjects. The molar LCAT rate (μmol · 1 −1 · h −1) did not differ between normolipidemic cases and controls while it was lower in type IV patients with coronary artery disease than in the type IV controls. The HDL total cholesterol (TC) concentration and the HDL-TC/TC ratio were lower in normolipidemic cases than in normolipidemic controls while both cases and controls with type IV hyperlipidemia showed equally low levels of these parameters. In conclusion, both a reduced fractional LCAT rate and a decreased HDL-TC/TC ratio might be indicators of disturbances of the cholesterol ester metabolism and might contribute to the development of coronary atheromatosis.