[Determination of potentially atherogenic triglyceride-rich lipoprotein particles]

Hypertriglyceridemia is a common disorder of lipid transport occurring either as a primary or secondary manifestation of the underlying metabolic derangement. Although most prospective studies have provided no evidence for the independent contribution of plasma triglycerides to atherosclerosis, results of several clinical and metabolic studies have indicated that some modified triglyceride-rich lipoproteins may be as atherogenic as the typical cholesterol-rich low density lipoproteins. Our studies on the sequential fractionation of apolipoprotein B-containing lipoproteins have identified five major apolipoprotein-defined lipoprotein families including cholesterol-rich lipoprotein B and triglyceride-rich lipoproteins B:C, B:C:E, B:E and A-II:B:C:D:E. The evaluation of the results of Cholesterol Lowering Atherosclerosis Study has shown that some triglyceride-rich lipoproteins play an important role in the progression of atherosclerosis. The combined niacin-colestipol treatment resulted in a 40-50% decrease in the levels of cholesterol-rich lipoprotein B but had no effect on triglyceride-rich lipoproteins. Patients who had increased levels of latter lipoproteins, as demonstrated by decreased levels of apolipoprotein C-III in heparin-Mn++ supernates, showed progression of atherosclerotic lesions. On the other hand, in the Helsinki Heart Study, despite minimal reduction in the levels of LDL-cholesterol, patients with phenotypes IIB and IV had higher reduction rates in coronary end points than patients with phenotype IIA.(ABSTRACT TRUNCATED AT 250 WORDS)