Concentration and chemical composition of plasma lipoprotein subfractions in patients with peripheral vascular disease. Evidence for normal apolipoprotein B but low cholesteryl ester content in small VLDL.

Subfractionation of the 3 major plasma lipoprotein classes was performed in 20 male patients with symptomatic peripheral vascular disease (PVD) and 18 male healthy controls of similar age and serum lipid levels as the patients in order to investigate if, at comparable levels of total serum lipids, any difference in the distribution or the chemical composition of the lipoprotein subfractions existed between patients and controls. Concentrations of free and esterified cholesterol, triglycerides, phospholipids, apolipoprotein B (apo B) and soluble apolipoproteins did not differ significantly in any lipoprotein subfraction of PVD patients compared to controls. Calculated molecular weights and numbers of lipoprotein particles/ml plasma were also similar in the 2 groups except that there were more heavy LDL particles in the patient group. Plotting concentrations of apo B against cholesteryl ester in the VLDL-D subfraction (Sf 20-100) yielded a linear regression in both groups. The PVD regression line was significantly steeper than that of controls. Calculation of the molecular mass of the various constituents of the VLDL-D fraction in the subjects with the highest content of esterified cholesterol in VLDL-D, where this difference was most pronounced, suggests that this difference was due entirely to a decreased number of cholesteryl ester molecules per lipoprotein particle in PVD. The findings suggest that a disordered metabolism of plasma cholesteryl esters may be present in certain PVD patients.