Lipoproteins in patients with proved coronary artery disease: qualitative and quantitative changes in agarose-gel electrophoretic patterns.

The relationship between the configuration of agarose-gel lipoprotein electrophoresis patterns and the extent of coronary artery disease (CAD) was studied in consecutive patients undergoing diagnostic coronary angiography. Three groups were identified: patients with normal coronary arteries (group 1), patients with minor luminal irregularities (group 2) and patients with significant coronary artery obstructions (group 3). Densitometric scans of the electrophoretograms were studied to determine the relative proportion of lipoproteins in each major fraction and the configuration of the pre-beta complex. The presence of multiple subfractions within the pre-beta lipoprotein complex had a sensitivity of 66% for the presence of CAD and a specificity of 99%. A decreased level of alpha 1 lipoproteins, defined as less than 25% of total lipoproteins, occurred almost entirely in groups 2 and 3, whereas an increased level (greater than or equal to 28%) of pre-beta lipoproteins was less specific for CAD. The proportions of alpha and pre-beta lipoproteins were inversely related (r = 0.677). Although abnormalities of serum cholesterol and/or triglycerides were common in groups 2 and 3, the detailed study of lipoprotein patterns provided a more sensitive index of disordered lipoprotein metabolism. The angiographic severity of CAD was significantly related to age and to levels of serum triglycerides, alpha 1 lipoproteins, and pre-beta lipoproteins. The lipoprotein electrophoretogram, in conjunction with serum lipid levels, is a valuable tool for demonstrating abnormalities of lipoprotein metabolism associated with CAD.