Further Methodological Studies on the Intravenous Fat Tolerance with Intralipid® Emulsion

Abstract

Factors affecting the reproducibility of the intravenous fat tolerance test (IVFTT) with the Intralipid® emulsion have been studied in man. Temperature variations of the emulsion at the time of injection did not affect the fractional removal rate k₂. Plasma samples could be treated at room temperature without affecting the k₂ value. Linear k₂ slopes were obtained also in pronounced hypertriglyceridaemia, which suggests that the test can be applied in subjects with wide ranges of serum triglyceride (TG) concentrations. In subjects with a wide range of serum lipids but at steady state with regard to lipid metabolism, the IVFTT was found to be highly reproducible when repeated with intervals of up to 6 months. Furthermore, the turnover of serum TG, determined as the product of the fractional removal rate and the serum TG concentration, was constant. Most Intralipid batches gave identical k₂ results. In some comparisons, batches were found which gave k₂ curves significantly different from the standard batches. It is recommended that the IVFTT is carried out only with Intralipid emulsions that have been standardized in this respect.

Key Words:

• Fat tolerance
• intravenous
• hypertriglyceridaemia
• Intralipid®
• triglyceride
• serum