Association of Hyperapobetalipoproteinemia with Endogenous Hypertriglyceridemia and Atherosclerosis

Abstract

Researchers disagree on whether plasma triglyceride levels are an independent risk factor for atherosclerotic coronary artery disease. It was hypothesized that patients with endogenous hypertriglyceridemia would differ: some would have normal values of plasma low density lipoprotein (LDL) B protein; others, despite their normal level of LDL cholesterol, would have increased levels of LDL B protein. It was believed the latter patients, those with hyperapobetalipoproteinemia, would be the ones at risk for atherosclerosis. Two populations were studied. Group 1, consisting of 162 patients with type IV lipoprotein patterns, was divided into 2 groups. One subgroup (A), which included 38 patients with elevated plasma LDL B protein levels, had a significantly higher prevalence of atherosclerotic disease than the other subgroup (B), which consisted of 36 patients with normal levels of plasma LDL B protein (10 patients vs. 2, P < 0.02). Group 2 consisted of 100 patients who had myocardial infarction; 81% of the 47 hypertriglyceridemic and 70% of the 53 normotriglyceridemic patients had elevated plasma LDL B protein levels (.gtoreq. 129 mg/dl), a proportion significantly higher than that in group 1 (P < 0.001). An elevated plasma level of LDL B protein not only identifies subgroups of patients with type IV lipoprotein patterns but also may be an important marker for atherosclerotic disease.