LDL Cholesterol Direct, Serum

The lipid profile is used to assess the risk of developing a heart disease and to monitor its treatment. Lipids are fats and fat-like substances which are important constituents of cells and are rich sources of energy. It is necessary to monitor and maintain healthy levels of these lipids to stay healthy. The results of the lipid profile are evaluated along with other known risk factors associated with heart disease to plan and monitor treatment. Treatment options like lifestyle changes such as diet and exercise or lipid-lowering medications such as statins may be considered depending on the values of the lipid profile. A lipid profile typically includes total cholesterol, high density lipoproteins (HDL), low density lipoprotein (LDL), chylomicrons, triglycerides, very low density lipoproteins (VLDL), Cholesterol/HDL ratio. The low-density lipoprotein (LDL) test is used as part of a lipid profile to assess the risk of heart diseases and to monitor its treatment. LDL is not measured directly but is calculated from the results of total cholesterol, HDL and triglycerides. This calculation is accurate in most of the cases but becomes inaccurate when triglycerides are high (i.e., > 400 mg/dL). In such cases, LDL is to be measured directly. LDL is considered the most important form among all the other forms of cholesterol to determine the risk of heart disease. It is often called undesirable or bad cholesterol as it deposits excess cholesterol in the blood vessels and contributes to atherosclerosis. Treatment options like lifestyle changes such as diet and exercise or lipid-lowering medications such as statins may be considered depending on the values of the lipid profile. Additionally the number of LDL particles (LDL-P) and/or their size may be useful to determine risk of heart disease in certain people.

1. What is a low-density lipoprotein (LDL) test?

The low-density lipoprotein (LDL) test is used as part of a lipid profile to assess the risk of heart diseases and to monitor its treatment. LDL is not measured directly but is calculated from the results of total cholesterol, HDL and triglycerides. This calculation is accurate in most of the cases but becomes inaccurate when triglycerides are high (i.e., > 400 mg/dL). In such cases, LDL is to measured directly.

2. What is LDL-P test?

LDL-P test measures the number of LDL particles, rather than measuring the amount of LDL-cholesterol. The number of LDL particles, and their size, is an additional factor to consider when determining the risk for cardiovascular diseases.

3. What is the plan of treatment if lipid levels are unhealthy?

Lifestyle modifications are necessary to maintain healthy lipid levels. A diet low in saturated fat and trans unsaturated fats, avoiding smoking, controlling hypertension and diabetes, and moderate exercise. Drug therapy may be initiated on the basis of the results of the lipid profile.

4. How is LDL calculated?

Often laboratories use a formula called Freidewald's formula to calculate LDL. It the results of the parameters of Lipid Profile that are measured directly. The results are accurate only if triglycerides are < 400 mg/dL.

LDL cholesterol = Total cholesterol – ( HDL + triglycerides/5)