Cholesterol and Triglyceride Tests

Definition
Purpose
Description
Precautions
Side effects
Interactions

Definition

Cholesterol and triglyceride tests are components of a lipid profile that provide important data about an individual’s risk for developing cardiovascular (heart) disease.

Purpose

The purpose of cholesterol and triglyceride tests is to evaluate an individual’s risk of cardiovascular (heart) disease.

Description

The body uses cholesterol when building cells and producing hormones. An excess of cholesterol in the blood can build up along the inside of the artery walls, forming plaque. Large amounts of plaque increase the chances of having a heart attack or stroke.

Triglycerides are a type of fat the body uses for storing energy. Only small amounts are found in the blood. Having a high triglyceride level along with a high LDL cholesterol may increase a person’s risk of having heart disease more than having only a high LDL cholesterol level.

Cholesterol and triglyceride testing is done for several reasons.

• As a component of a routine physical examination to screen for a lipid disorder.
• To evaluate an individual’s risk for heart disease.
• To evaluate an individual’s response to drugs used to treat lipid disorders.
• To check for a rare genetic disease that causes very high cholesterol levels in persons that have unusual symptoms such as yellow fatty deposits in the skin(xanthomas).

Cholesterol and triglyceride tests are components of a lipid profile. A lipid profile includes four blood tests: total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides.

Dietary fats, including cholesterol, are absorbed from the small intestines. They are converted into triglycerides, which are then packaged into lipoproteins. All of these products are transported into the liver by chylomicrons. After a fast (not eating) lasting at least 12 hours, chylomicrons are absent from the

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

• Cholesterol and triglyceride tests are typically ordered by a family doctor, internist or geriatrician.
• A blood sample is usually obtained by a nurse, phlebotomist or medical technologist.
• The blood sample is tested or processed by a medical technologist.
• Results are usually reviewed, returned to the person being tested and interpreted by the physician initially ordering the lipid profile.

bloodstream. This is the reason why persons that are having an LDL test must fast overnight.

A desirable cholesterol level is less than 200 mg/dL.

• Desirable: Less than 200 mg/dL
• Borderline high: 200-239 mg/dL
• High: 240 mg/dL or more

A healthy triglyceride level is 150 mg/dL or less.

• Normal: Less than 150 mg/dL
• Borderline high: 150-199 mg/dL
• High: 200-499 mg/dL
• Very high: 500 mg/dL and higher

Pharmaceutical interventions are based, in part, on cholesterol and triglyceride test values.

Cholesterol and triglyceride levels vary according to a person’s age and gender.

Ranges for cholesterol and triglyceride values vary slightly among different laboratories.

Cholesterol and triglyceride tests can be ordered at any time. Routine lipid profiles that are used to monitor the effectiveness of drugs intended to reduce serum cholesterol are usually performed every three months.

Some medical experts recommend routine cholesterol and triglyceride testing to screen for problems that affect the way cholesterol is produced, used, carried in the blood, or disposed of by the body.

Precautions

A fast (not eating) for a minimum of 12 hours before drawing blood contributes to a more accurate

QUESTIONS TO ASK YOUR DOCTOR

• Why are cholesterol and triglyceride tests needed?
• What do the results indicate for my health?
• What treatment options do I have?

measurement of cholesterol and triglycerides in the blood. No other precautions are needed.

At the time of drawing blood, the only precaution needed is to clean the venipuncture site with alcohol.

Side effects

The most common side effects of cholesterol or triglyceride tests are minor bleeding (hematoma) or bruising at the site of venipuncture.

Interactions

There are no interactions for a cholesterol or triglyceride test.

Resources

BOOKS

Fischbach, F. T. and M. B. Dunning. A Manual of Laboratory and Diagnostic Tests. 8th ed. Philadelphia: Lippincott Williams & Wilkins, 2008.

McGhee, M. A Guide to Laboratory Investigations. 5th ed. Oxford, UK: Radcliffe Publishing Ltd, 2008.

Price, C. P. Evidence-Based Laboratory Medicine: Principles, Practice, and Outcomes. 2nd ed. Washington, DC: AACC Press, 2007.

Scott, M.G., A. M. Gronowski, and C. S. Eby. Tietz’s Applied Laboratory Medicine. 2nd ed. New York: Wiley-Liss, 2007.

Springhouse, A. M.. Diagnostic Tests Made Incredibly Easy!. 2nd ed. Philadelphia: Lippincott Williams & Wilkins, 2008.

PERIODICALS

Amati, L., M. Chilorio, E. Jirillo, and V. Covelli. “Early pathogenesis of atherosclerosis: the childhood obesity.” Current Pharmaceutical Design 13, no. 36 (2007): 3696–3700.

Leigh-Hunt, N., and M. Rudolf. A review of local practice regarding investigations in children attending obesity clinics and a comparison of the results with other studies.” Child Care Health and Delivery 34, no. 1(2008): 55–58.

Shephard, M. D., B. C. Mazzachi, and A. K. Shephard. “Comparative performance of two point-of-care analysers for lipid testing.”Clinical Laboratory 53, no. 9-12 (2007): 561–566.

KEY TERMS

Hematoma— A collection of blood that has entered a closed space.

Phlebotomist— Health care professional trained to obtain samples of blood.

Wright, J. T., S. Harris-Haywood, S. Pressel, et al. “Clinical outcomes by race in hypertensive patients with and without the metabolic syndrome: Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial.” Archives of Internal Medicine 168, no. 2 (2008): 207–217.

ORGANIZATIONS

American Association for Clinical Chemistry. http://www.aacc.org/AACC/.

American Society for Clinical Laboratory Science. http://www.ascls.org/.

American Society of Clinical Pathologists. http://www.ascp.org/.

College of American Pathologists. http://www.cap.org/apps/cap.portal.

OTHER

American Clinical Laboratory Association. “Information about clinical chemistry.” 2008 [cited February 24, 2008]. http://www.clinical-labs.org/.

Clinical Laboratory Management Association. “Information about clinical chemistry.” 2008 [cited February 22, 2008]. http://www.clma.org/.

Lab Tests On Line. “Information about lab tests.” 2008 [cited February 24, 2008]. http://www.labtestsonline.org/.

National Accreditation Agency for Clinical Laboratory Sciences. “Information about laboratory tests.” 2008 [cited February 25, 2008]. http://www.naacls.org/.

L. Fleming Fallon, Jr, MD, DrPH

Cholesterol tests seeLipid tests

Circulation support seeMechanical circulation support