Triglyceride and cholesterol metabolism in primary hypertriglyceridemia.

To determine mechanisms of elevated plasma triglycerides (TG) in patients with primary hypertriglyceridemias, simultaneous studies were carried out on kinetics of very low density lipoprotein-triglycerides (VLDL-TG) and synthesis of cholesterol and bile acids. Sixteen hypertriglyceridemic patients with familial combined hyperlipidemia (FCHL) and 12 patients with poorly classified, primary hypertriglyceridemia were studied, and their results were compared to a series of normal and obese subjects previously studied in our laboratory. The mean value for transport (synthesis) of VLDL-TG in patients with FCHL was about twice normal. Although the upper normal synthesis rates overlapped with transport rates of some patients with FCHL, it appeared that the major cause of hypertriglyceridemia in FCHL was an elevated production of VLDL-TG. However, the height of the plasma TG in FCHL patients also was influenced by individual clearance capacities for VLDL-TG, and fractional clearance rates in several seemed particu...