Dysregulated very-low density lipoprotein (VLDL)-triacylglycerol (TG) metabolism in obesity may account for hypertriacylglycerolaemia and increased cardiovascular disease.
Omega-3 fatty acid ethyl esters (ω-3 FAEEs) decrease plasma TG and VLDL concentrations, but the mechanisms are not fully understood.

In this study, we carried out a 6-week randomized, placebo-controlled study to examine the effect of high dose ω-3 FAEE supplementation (3.2g/day) on the metabolism of VLDL-TG in obese men using intravenous administration of d5-glycerol. We also explored the relationships of VLDL-TG kinetics with the metabolism of VLDL-apolipoprotein (apo) B-100 and high density lipoprotein (HDL)-apoA-I. VLDL-TG isotopic enrichment was measured using gas chromatography-mass spectrometry. Kinetic parameters were derived using a multicompartmental model.

Compared with placebo, ω-3 FAEE supplementation significantly lowered plasma concentrations of total (-14%, P<0.05) and VLDL-TG (-32%, P <0.05), as well as hepatic secretion of VLDL-TG (-32%, P<0.03). The fractional catabolic rate (FCR) of VLDL-TG was not altered by ω-3 FAEEs. There was a significant association between the change in secretion rates of VLDL-TG and VLDL-apoB-100 (r=0.706, P<0.05).

However, the change in VLDL-TG secretion rate was not associated with change in HDL-apoA-I FCR (r=0.139, P<0.05).

Our results suggest that the TG-lowering effect of ω-3 FAEEs is associated with decreased VLDL-TG secretion rate and hence lower plasma VLDL-TG concentration in obesity. The changes in VLDL-TG and apoB-100 kinetics are closely coupled.