Distinct patterns of lipoproteins with apoB defined by presence of apoE orapoC-III in hypercholesterolemia and hypertriglyceridemia

Apolipoprotein (apo) E and apoC-III concentrations in VLDL and LDL are asso ciated with coronary heart disease. We studied die relationship between apo E and apoC-III and the abnormal concentrations and distribution of apoB lip oproteins in 10 hypercholesterolemic and 13 hypertriglyceridemic patients c ompared with 12 normolipidemic subjects (mean age, 45 years). Sixteen disti nct types of apoB lipoprotein particles were separated by first using anti- apoE and anti-apoC-III immunoaffinity chromatography in sequence and then u ltracentrifugation [light VLDL, dense VLDL, IDL, and LDL, with apoE with or without apoC-III (E+C-III+, E+C-III-) or without apoE with or without apoC -III (E-C-III+, E-C-III-)]. The concentrations of VLDL particles with apoC- III (E+C-III+, E-C-III+) were increased in the hypertriglyceridemic group c ompared with the hypercholesterolemic and normolipidemic groups. These part icles were the most triglyceride rich of the particle types, and their trig lyceride content was twice as high in hypertriglyceridemics compared with t he other two groups. Hypertriglyceridemics had a similar concentration of t otal E-C-III- particles compared with normolipidemics, but the E-C-III- par ticles were distributed more to VLDL and IDL than to LDL. Hypercholesterole mics, in contrast, were distinguished from the normolipidemic group by 2-fo ld higher concentrations of apoB lipoproteins without apoE or apoC-III (E-C -III-), mainly LDL, which had high cholesterol content. Nonetheless, both n ormolipidemics and hypercholesterolemics had apoC-III-containing VLDL, whic h comprised 68% and 43% of their total VLDL particles. E+C-III- particles w ere a minor type, comprising < 10% of particles in all lipoproteins and pat ient groups.ie Therefore, VLDL particles with apoC-III may play a central r ole in identifying the high risk of coronary heart disease in hypertriglyce ridemia, but their substantial prevalence in normolipidemics may be of clin ical significance as well.