Intravenous fat tolerance. Correlation with very low density lipoprotein apoprotein B kinetics in man.
The intravenous fat tolerance test (IVFTT) has been introduced as a measure of the fractional catabolic rate of the endogenous triglyceride of plasma. To assess the validity of this test we have compared this test in 21 normal and hyperlipidaemic subjects with direct measurement of the fractional catabolic rate of autologous radio-iodinated VLDL. There was a strong positive correlation between the rate constant K2 of the IVFTT and the fractional catabolic rate of VLDL-apolipoprotein B (r=+0.87). The two rates were considerably different in magnitude. The IVFTT appears to be a valid index of the fractional catabolic rate of VLDL. Its limitations and uses are discussed.