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: K₁ that describes the maximal removal rate and K₂ that measures the fractional removal rate of the injected triglycerides.

K₁ did not vary with age or correlate with either K₂ or the plasma triglyceride level. K₂ was lower in the older than in the younger control subjects. The older subjects also had higher plasma triglyceride values. K₂ was furthermore significantly lower in the hyperlipidaemic patients than in the old control subjects; all the former patients had K₂-values below the mean value for the older control group.

When all values for K₂ 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 K₁ and K₂, as well as the clinical implications of reduced fat tolerance were briefly discussed.