Apoprotein measurements and their clinical application.

The apoproteins structurally are closely associated with specific lipoproteins, for example, apoprotein B with VLDL and LDL and apoprotein A-I with HDL. The levels of these apoproteins provide information about the plasma concentrations and metabolism of the lipoproteins with which they are associated. The levels of apoprotein B and apoprotein A-I and the Lp(a) lipoprotein can serve as important predictors of coronary heart disease risk and can provide information not available from blood lipid and lipoprotein lipid levels. For clinicians and public health interests, the decision to use apoprotein measurements and to estimate cardiovascular risk depends on the clinical setting, the availability of standardized apoprotein methods that can be related to age- and sex-specific population-based reference values, and the cost of the measurements. In addition, these apoproteins can be used in specific cases to answer diagnostic questions and provide information about therapeutic response.