This test measures the concentration of very low-density lipoprotein (VLDL) cholesterol, which is a type of lipoprotein that carries triglycerides and cholesterol in the blood and is a precursor to low-density lipoprotein (LDL) cholesterol, using a calculation based on the total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride levels, or a direct immunoseparation assay, to help assess cardiovascular risk and guide decisions about lipid-lowering therapy, as elevated VLDL cholesterol levels are associated with increased risk of atherosclerosis and coronary heart disease.