Apolipoprotein C-III and the Metabolic Basis for Hypertriglyceridemia and the Dense Low-Density Lipoprotein Phenotype

BACKGROUND: Here, we aim to identify defects of apolipoprotein (apo) B lipoprotein metabolism that characterize hypertriglyceridemia, focusing on apoC-III and apoE. METHODS AND RESULTS: We studied the transport of plasma apoB within 21 distinct subfractions as separated by anti-apoC-III and anti-apoE immunoaffinity chromatography and ultracentrifugation in 9 patients with moderate hypertriglyceridemia and 12 normotriglyceridemic control subjects. Hypertriglyceridemia was characterized by a 3-fold higher liver secretion of very low-density lipoprotein (VLDL) that had apoC-III but not apoE and a 50% lower secretion of VLDL with both apoC-III and apoE (both P<0.05). This shift in VLDL secretion pattern from apoE to apoC-III resulted in significantly reduced clearance of light VLDL (-39%; P