The effects of an omega-3 ethyl ester concentrate on blood lipid concentrations in patients with hyperlipidaemia

The objective of this study was to investigate the effects and tolerability of an omega-3 ethyl ester concentrate (Omacor(trade mark)) on serum lipid concentrations in patients with hyperlipidaemia. A multicentre, double-blind, randomised, placebo-controlled trial was performed in the hospital and general practice setting. 84 patients with hyperlipidaemia were given a therapeutic lipid-lowering diet for 10 weeks. Of these, 55 patients were randomised to a 12-week treatment period. 47 patients completed the study and two patients withdrew because of adverse events. Randomised patients received omega-3 ethyl ester concentrate or corn oil (placebo), both administered at a dose of 2g twice daily in soft gelatin capsules. Main outcome measures included changes in eicosapentaenoic acid (EPA)/ docosahexaenoic acid (DHA) content of serum phospholipids, total serum triglycerides, total serum cholesterol, and high density lipoprotein (HDL) cholesterol between baseline (week 10) and the end of treatment (week 22). After 12 weeks of treatment, patients receiving the omega-3 ethyl ester concentrate showed a significant increase in the EPA/DHA content of serum phospholipids (p < 0.0001). No significant changes in serum phospholipids were observed in the patients given placebo. A mean [standard deviation (SD)] reduction in serum triglyceride of 28.3 (19.1)% (p = 0.0001) occurred in patients given the omega-3 ethyl ester concentrate. Patients receiving corn oil showed a nonsignificant mean (SD) increase in serum triglyceride of 9.1 (24.8)%. Therefore, a difference between the groups of 37.4% in favour of active treatment was found (p < 0.0001). Total serum cholesterol did not change significantly in either treatment group. Mean (SD) HDL cholesterol concentrations showed an increase of 0.9 (21.6)% in patients receiving omega-3 ethyl ester concentrate and 3.6 (24.3)% in the corn-oil group; however, neither increase was significant. In conclusion, omega-3 ethyl ester concentrate, 4 g/day, produced a significant reduction in mean serum triglyceride concentration in patients with hyperlipidaemia and was well tolerated.