Effect of fish oil treatment on plasma lipoproteins in type III hyperlipoproteinaemia

Nine patients with type III hyperlipoproteinaemia and homozygosity for the apolipoprotein E2 isoform were treated with 15 g daily of MaxEPA, a fish oil preparation rich in eicosapentaenoic acid (2.7 g daily) and docosahexaenoic acid (1.8 g daily) for 16 weeks. Plasma lipoprotein and apolipoprotein concentrations were compared with those obtained during treatment with an olive oil preparation. MaxEPA treatment decreased plasma median total cholesterol, triglyceride and apolipoprotein B concentrations by 16, 53 and 19%, respectively. Plasma median very low density lipoprotein (VLDL)-cholesterol, triglyceride and apolipoprotein B concentrations were reduced by 45, 62 and 75% respectively, while the abnormal VLDL-cholesterol/triglyceride ratio remained unchanged. Individual reductions of VLDL concentrations varied considerably, for VLDL-cholesterol between 10 and 75%. In the majority of cases the abnormal late pre beta-bands on agarose electrophoresis, typical for type III hyperlipoproteinaemia normalized to pre beta-mobility on MaxEPA treatment. LDL-cholesterol and apolipoprotein B tended to increase after 8 weeks on MaxEPA but decreased again after 16 weeks. Median plasma high density lipoprotein cholesterol and apolipoprotein A-I did not change during MaxEPA treatment. It is concluded that MaxEPA have decreasing effects on plasma VLDL lipid and apolipoprotein concentrations in apolipoprotein E2 homozygous type III hyperlipoproteinaemia but that this effect is variable and unpredictable.