Test Details

Use

Evaluate hyperlipidemia as an index to coronary artery disease

Special Instructions

State patient's age and sex on the request form.

Test Includes

Cholesterol, total; high-density lipoprotein (HDL) cholesterol; low-density lipoprotein (LDL) cholesterol (calculation); triglycerides; very low-density lipoprotein (VLDL) cholesterol (calculation)

Limitations

Patients with obstructive liver disease may develop lipoprotein abnormalities. Serum lipid factors have not been demonstrated to have a strong influence on recurrent stenosis following coronary angioplasty, the pathogenesis of which is presently not well understood. LDL cholesterol cannot be calculated if triglyceride is >800 mg/dL.

Methodology

See individual tests.

Additional Information

Investigation of serum lipids is indicated in those with coronary and other arterial disease, especially when it is premature, and in those with family history of atherosclerosis or of hyperlipidemia. In this sense, the expression “premature” is mostly used to include those younger than 40 years of age. Patients with xanthomas should be worked up with lipid panels but not those with xanthelasmas or xanthofibromas in the sense of dermatofibromas. Those whose fasting serum is lipemic should have a lipid panel, but the serum of a subject with high cholesterol (but normal triglyceride) is not milky in appearance. The patient with high cholesterol (>240 mg/dL) should have a lipid panel. Patients with cholesterol levels between 200−240 mg/dL plus two other coronary heart disease risk factors should also have a lipid panel.1 In addition to application in screening programs for evaluation of risk factors for coronary arterial disease, lipid profiling may lead to detection of some cases of hypothyroidism. Primary hyperlipoproteinemia includes hypercholesterolemia, a direct risk factor for coronary heart disease. Secondary hyperlipoproteinemia includes increases of lipoproteins secondary to hypothyroidism, nephrosis, renal failure, obesity, diabetes mellitus, alcoholism, primary biliary cirrhosis, and other types of cholestasis. Decreased lipids are found with some cases of malabsorption, malnutrition, and advanced liver disease. In abetalipoproteinemia, cholesterol is <70 mg/dL.

Specimen Requirements

Information on collection, storage, and volume

Specimen

Serum (preferred) or plasma

Volume

1 mL

Minimum Volume

0.7 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Hemolysis

Collection

Separate serum or plasma from cells within 45 minutes of collection. Lipid panels are best avoided for three months following acute myocardial infarction, although cholesterol can be measured in the first 24 hours.