LDL concentration is correlated with the removal from the plasma of a chylomicron-like emulsion in subjects with coronary artery disease

Abstract

In animal model studies, the uptake of chylomicron remnants after entering in the space of Disse occurs mainly by low-density lipoprotein (LDL) receptor and LDL receptor-related protein (LRP). In subjects, the relative importance of each one of these receptors for the clearance of chylomicron remnants is not fully understood. In our study, LDL cholesterol and apolipoprotein (apo) B were correlated to the plasma kinetics of a chylomicron-like emulsion in 77 subjects (11 women, mean age 58±12 years) with coronary artery disease (CAD). Their total cholesterol was 227±25 mg/dl, triglyceride 159±25 mg/dl, LDL cholesterol 148±27 mg/dl, HDL cholesterol 40±9 mg/dl, apo A1 1.80±0.53 g/l and apo B 1.65±0.48 g/l. The emulsion was double-labeled with 3H-triolein and 14C-cholesteryl oleate and injected intravenously after 12-h fasting. The decay curves of the radioisotopes were determined from blood samples collected at predetermined intervals during 60 min. A negative correlation between FCR of the emulsion cholesterol esters and LDL cholesterol and apo B plasma concentrations was found ( r=−0.4, P=0.005 and r=−0.3, P=0.01, respectively) whereas FCR of the emulsion triglycerides did not correlate with any of the plasma lipids or apolipoprotein parameters. Concluding, in patients with CAD, LDL catabolic pathway significantly influences the removal from plasma of chylomicron remnants.