Total Cholesterol (TC), HDL and LDL Tests
What is the purpose of this test? | This test is a complement to normal check-ups. It is used to assess the risk of cardiovascular disease. It is also used to diagnose abnormal cholesterol levels. |
How to prepare: |
For this blood test, you must:
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Treatment initiation*: |
The decision to begin treatment is based on the evaluation of the risk of cardiovascular disease for the patient after 10 years.
When to start ? Moderate risk (10 to 19 %):
High risk (≥ 20 %):
Other condition :
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Target values*: |
Target values (lifestyle changes in all - drug, if necessary). LDL is the primary target : Moderate to high risk (≥ 10 %) :
Other condition :
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Associated tests: | Triglycerides are measured at the same time. Other complementary tests include apolipoprotein B and apolipoprotein A1 levels, hs-CRP and glycemia. As part of a complete check-up, a complete blood count is often ordered. |
General Information
Cholesterol comes from two primary sources. It is produced by the liver and is also found in the foods we eat. It is an important substance that is essential for the proper functioning of our body. There is a relationship however, between blood cholesterol levels and the risk of cardiovascular disease. In other words, the higher your blood cholesterol level, the greater your risk for cardiovascular disease.
Cholesterol is transported by lipoproteins. There are two main types of lipoproteins : LDL and HDL. LDL transports cholesterol from the liver to tissues throughout the body. This type of cholesterol tends to settle in the arteries and to block them. It is often referred to as "bad" cholesterol since elevated LDL levels are a risk factor for cardiovascular disease. HDL on the other hand, picks up the cholesterol that has been deposited in the blood vessels and transports it back to the liver. HDL is known as "good" cholesterol.
A patient's total cholesterol/HDL ratio (TC/HDL ratio) can be used to assess the risk of cardiovascular disease. A high ratio is an additional risk factor for cardiovascular disease.
What does an abnormal test result mean?
If the result is too high
Total cholesterol and LDL: high levels increase the risk of cardiovascular disease (e.g. angina pectoris, infarction).
LDL levels may be elevated for various reasons, including :
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HDL: high levels are a good thing. Physical activity, quitting smoking, weight loss and moderate alcohol intake all increase HDL.
If the result is low
LDL and total cholesterol: it is desirable to have a low result, since it reduces the risk of suffering from a cardiovascular disease. Some factors can, however, lead to low cholesterol levels:
- Chronic anemia
- Cancer
- Hyperthyroidism
- Severe liver disease
- Malnutrition
Factors that can interfere with test accuracy
Failure to comply with test preparation, changes to one's usual diet or recent weight loss (less than 2 weeks prior to the test), heart attack (≤ 12 weeks), trauma (surgery, viral or bacterial infection), pregnancy or recent delivery (less than 8 weeks prior to the test) can give results that do not reflect the lipid status of the person.
What you need to know before the test
Before going for a blood test, examination or procedure, it is always a good idea for you to have a complete list of all prescription and over the counter medications and/or natural products you may be taking. If you are unsure or have any questions, your pharmacist will be able to provide you with additional information.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.