Constant infusion rates of lipid emulsions to stabilize plasma triglyceride concentrations: Medium-chain triglyceride/long-chain triglyceride emulsions (MCT/LCT) versus LCT

Abstract

As medium-chain triglyceride emulsions (MCT) are more rapidly hydrolyzed than long-chain triglyceride emulsions (LCT), MCT/LCT tends to be infused faster than LCT. The purpose of the present study was to determine the most appropriate infusion rate for MCT/LCT to stabilize plasma concentrations of triglyceride (TG), being equivalent to the optimal infusion rate of the emulsion. A TG clamp was set up by raising the mean ± SD concentrations of TG in plasma, being 1.08 ± 0.18Δ mmoll⁻¹ for LCT, and 1.65 ± 0.31 Δ mmoll⁻¹ for MCT/LCT after a 50-min priming infusion of each emulsion. Thereafter, the infusion rate of lipid was controlled every 10 min to maintain a steady concentration of TG for a period of 150 min. A constant infusion of glucose at 0.32 g/kg body weight (BW) per h was administered for the test period. The weight-based rate of the infusion to maintain a steady state of plasma TG concentrations did not differ between MCT/LCT and LCT, being 0.125 ± 0.013vs 0.117 ± 0.021 g/kg BW per h, while the molar-based infusion rate was 0.203 ± 0.021 mmol/kg BW per h for MCT/LCT and 0.132 ± 0.023 mmol/kg BW per h for LCT (P < 0.05). These results suggest that although 54% more molar MCT/LCT-TG can be hydrolyzed during a constant infusion, MCT/LCT should not be infused at a rate faster than 0.1 g/kg BW per h under a steady state.