<qa>  What is a technique for analyzing lipoprotein?This study was designed to explore the effects of omega-3-acid ethyl esters on the lipid and lipoprotein profile in the blood in hyperlipidemic patients receiving a hydroxymethylglutaryl-coenzyme A HMG-CoA reductase inhibitor in comparison with the control group of patients not treated with omega-3-acid ethyl esters in an unblinded manner by use of high performance liquid chromatography HPLC using highly-sensitive gel filtration columns, which is a technique for analyzing lipoprotein. 