Apolipoproteins play a critical role in regulating cellular uptake of lipoproteins by specific receptors, regulating the activities of lipoprotein lipase and lecithin-cholesterol acyl transferase, and in the indirect regulation of the intracellular enzymes, acyl-cholesterol acyl transferase and HMG Co-A reductase. This study provided insight into the role of environmental and genetic effects on phenotypic variation of the individual components of the molecules of lipid metabolism as well as on the relationships between components.