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The Test Sample
What is being tested?
Triglycerides are a form of fat and a major source of energy for the body. This test measures the amount of triglycerides in the blood.
Most triglycerides are found in fat (adipose) tissue, but some triglycerides circulate in the blood to provide fuel for muscles to work. After a person eats, an increased level of triglycerides is found in the blood as the body converts the energy not needed right away into fat. Triglycerides move via the blood from the gut to adipose tissue for storage. In between meals, triglycerides are released from fat tissue to be used as an energy source for the body. Most triglycerides are carried in the blood by lipoproteins called very low-density lipoproteins (VLDL).
High levels of triglycerides in the blood are associated with an increased risk of developing cardiovascular disease (CVD), although the reason for this is not well understood. Certain factors can contribute to high triglyceride levels and to risk of CVD, including lack of exercise, being overweight, smoking cigarettes, consuming excess alcohol, and having medical conditions such as diabetes and kidney disease.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm. Sometimes, a drop of blood is collected by puncturing the skin on a fingertip. This fingerstick sample is typically used when a lipid profile (total cholesterol, HDL-C, LDL-C and TG) is being measured on a portable testing device, for example, at a health fair.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
Current standards recommend that testing be done when you are fasting. For 9 to 12 hours before the test, only water is permitted. Your healthcare practitioner may decide that you may be tested without fasting. Follow any instructions you are given and tell the person drawing your blood whether or not you have fasted. In addition, alcohol should not be consumed for 24 hours just before the test.