Broad-beta disease versus endogenous hypertriglyceridemia: levels and lipid composition of chylomicrons and very low density lipoproteins during fat-free feeding and alimentary lipemia.

To assess the roles of endogenous and exogenous lipid in the production of the abnormal lipoprotein patterns characteristic of broad-beta desease (with a type IVIII lipoprotein pattern) and endogenous hypertriglyceridemia (with a type IV pattern), oral fat loads (50 g/M-2) were administered to six subjects with broad-beta disease and to eight with endogenous hypertriglyceridemia following at leat 72 hr of 0% fat, 85% carbohydrate isocaloric formula feeding. Total plasma and Sf greater than 400, 100-400, 60-100, 30-60, and 20-30 lipoprotein cholesterol, triglyceride, and phospholipid levels were measured at 0 hr, 6 hr (at or before the peak of alimentary lipemia), and 24 hr following the fat load. Following fat-free feeding the levels and composition of the endogenous Sf greater than 400 lipoproteins were similar in both disorders; whereas total Sf20-400, and most notably, Sf 30-60 and 20-30 levels were increased and enriched in cholesterol in the subjects with broad-beta disease.