Plasma cholesterol esterification in hypertriglyceridaemia.

Plasma cholesterol esterification was assessed in hypertriglyceridaemic patients and normal subjects by two in vitro methods, one using autologous substrate and one using exogenous substrate. There was a significant negative correlation between cholesterol esterification rate and the plasma triglyceride concentration when this was assessed with autologous substrate or with substrate from a hypertriglyceridaemic donor. The percentage of esterified cholesterol in plasma and the esterification rate were always reduced when the plasma triglyceride concentration exceeded 7 mmol/1 and the rate of esterification rose significantly with appropriate triglyceride-lowering therapy in such patients. Evidence is presented that the impaired cholesterol esterification observed in severe hypertriglyceridaemia is secondary to a reduced concentration of substrate high density lipoprotein cholesterol, as well as to an excess of large triglyceride-rich lipoproteins.