Fish oil supplementation reduces β-very low density lipoprotein in type III dysbetalipoproteinemia

Abstract

β-Very low density lipoproteins (β-VLDLs) are atherogenic, cholesterol-rich chylomicron and VLDL remnants that accumulate in the plasma of type III dysbetalipoproteinemic subjects. To evaluate the effect of fish oil supplementation on plasma β-VLDL concentrations, we compared the lipid and lipoprotein responses in nine type III and nine type IV hyperlipidemic subjects. Each individual received 6 g/day ω-3 fatty acids for 12 weeks. Before treatment, the mean total cholesterol, total triglyceride, VLDL triglyceride, low density lipoprotein (LDL) cholesterol, and high density lipoprotein (HDL) cholesterol levels were not different between groups. Conversely, VLDL cholesterol, intermediate density lipoprotein (IDL) cholesterol, and IDL triglycerides were higher in type III than in type IV subjects. Fish oil supplementation was associated with significantly lower levels of cholesterol (-50%), triglycerides (-50%), and apolipoprotein B (-50%) in the d<1.006 g/ml ultracentrifugation plasma fraction in both groups, compatible with a reduction in VLDL in type III and type IV subjects, and in β-VLDL in type III subjects. This finding was confirmed by analysis of the plasma zonal ultracentrifugation profile and the agarose gel electrophoretic pattern of lipoproteins, which showed a reduction in but not a disappearance of remnant particles, suggesting that not all β-VLDL had been cleared after treatment. The levels of IDL cholesterol and IDL triglycerides (1.006 <1.006 g/ml plasma fraction in type III and type IV hyperlipidemias. In addition, fish oils reduce chylomicron and VLDL remnant concentrations in type III dysbetalipoproteinemia.