Plasma cholesterol esterification rate in type IV hyperlipoproteinemia. Relation to bile acid kinetics and triglyceride metabolism.

The LCAT rate, VLDL triglyceride turnover, and bile acid kinetics were determined under standardized conditions in 10 patients with primary type IV HLP. Bile acid and plasma VLDL triglyceride kinetics were determined with the aid of [14C]-labeled cholic and chenodeoxycholic acid and [3H]glycerol, respectively. The LCAT rate was simultaneously determined in fasting-state plasma. The mean values of total bile acid formation (21.2 +/- 2.6 mumol kg-1 day-1), apparent VLDL triglyceride production (19.6 +/- 2.0 mumol kg-1 hr-1), and LCAT rate (6.0 +/- 0.6 mumol kg-1 hr-1) exceeded those reported previously for healthy controls. Plasma LCAT rate correlated positively with bile acid synthesis (R = 0.85, p less than 0.01) and with apparent plasma VLDL triglyceride production (R = 0.75, p less than 0.02). The results suggest that parallel disturbances in the regulation of cholesterol, bile acid, and lipoprotein metabolism occur in some patients with type IV HLP.