TRADITIONAL LIPOPROTEIN PROFILE - CLINICAL UTILITY, PERFORMANCE REQUIREMENTS, AND STANDARDIZATION

The lipid and lipoprotein parameters which are predominantly measured and effectively comprise the traditional lipoprotein profile include t otal cholesterol, high density lipoprotein (HDL) cholesterol, low dens ity lipoprotein (LDL) cholesterol, and triglyceride. Total cholesterol is accepted as the initial entry point in a case finding approach suc h as that recommended by the National Cholesterol Education Program (N CEP). HDL cholesterol, known to be a strong inverse predicator of risk , is an additional measurement to total cholesterol to improve risk as sessments. The evidence:for triglyceride association remains mixed: al though strong associations are found in some studies, the evidence as an independent risk factor is still incomplete. Triglyceride is theref ore measured primarily for LDL estimation. Final classification and po tential intervention is ultimately based on the measurement of LDL cho lesterol. Reliability in the measurement of total cholesterol, HDL, LD L, and triglyceride is especially important if the uniform decision po ints established by the NCEP are to be properly implemented. Attention must be placed on controlling preanalytical sources of variation, whi ch can account for as much as 60% of the total measurement variability . The major analytical source of error comes from matrix effects, whic h results in problems of proper analytical calibration. Instrument sys tem calibration should be verified by a comparison with an accuracy ba se using fresh patient specimens. CDC has established a network of ref erence method laboratories to provide access to these lipid and lipopr otein accuracy bases.