Application of a new intravenous fat tolerance test in the study of hypertriglyceridaemia in man

Abstract

A new intravenous fat tolerance test was performed in a group of younger and a group of older male normolipidemic subjects, as well as in a group of male patients with hyperlipoproteinaemia. In this tolerance test the disappearance of an injected fat emulsion from blood was characterized by 2 rate constants: K 1 that describes the maximal removal rate and K 2 that measures the fractional removal rate of the injected triglycerides. K 1 did not vary with age or correlate with either K 2 or the plasma triglyceride level. K 2 was lower in the older than in the younger control subjects. The older subjects also had higher plasma triglyceride values. K 2 was furthermore significantly lower in the hyperlipidaemic patients than in the old control subjects; all the former patients had K 2 -values below the mean value for the older control group. When all values for K 2 and plasma triglycerides were plotted against each other, K2 was found to decrease with increasing concentration of triglycerides in a hyperbolic fashion. The clinical use of the intravenous fat tolerance test, the possible physiological basis of K 1 and K 2 , as well as the clinical implications of reduced fat tolerance were briefly discussed.