The lipid profile is a blood test done to assess the status of fat metabolism in the body and is important in heart disease. This includes measuring lipids (fats) and its derivatives known as lipoproteins. Lipoproteins are compounds containing fat and proteins and include free cholesterol, cholesterol esters, triglycerides, phospholipids and apoproteins.
Which biochemical markers are used?
The blood is analysed by the laboratory to determine the levels of:
HDL (high density lipoprotein) cholesterol
LDL (low density lipoprotein) cholesterol
Serum VLDL (very low density lipoprotein) cholesterol
Total cholesterol comprises all the cholesterol found in various lipoproteins such as high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL). A total cholesterol test is a rough measure of all the cholesterol and triglycerides in the blood.
Triglycerides are neutral fats found in the tissue and blood. Triglycerides containing lipoproteins may also contribute to the disorders related to coronary heart disease. Persons with high triglycerides often have other conditions, such as diabetes and obesity, that also increase the chances of developing heart disease.
The main function of HDL is to help soak up excess cholesterol from the walls of blood vessels and carry it to the liver, where it breaks down and is removed from the body in the bile. It is thus called “good” cholesterol as persons with high levels of HDL may have a lower incidence of heart disease.
LDL contains the greatest percentage of cholesterol and is responsible for cholesterol deposits on the walls of the artery resulting in coronary artery disease. LDL is thus known as the “bad” cholesterol. VLDL stands for very low density lipoprotein. VLDL contains the highest amount of triglyceride. VLDL is considered a type of bad cholesterol, because it helps cholesterol build up on the walls of arteries. Normal VLDL cholesterol level is between 5 and 40 mg/dL.
The cholesterol/HDL ratio is derived by dividing the total cholesterol by the HDL. This ratio helps in assessing the risk of heart disease in individuals.
What are the desirable lipid profile values?
Lipid profile values can be evaluated from the table below:
What preparations are required?
The patient needs to be fasting for 12–14 hours before drawing the sample. He should also be on his normal diet pattern. Intake of alcohol on the previous night should be avoided.
What are the factors that affect lipid profile?
Factors that affect an individual’s lipid profile include:
Alcohol and tobacco use
Chronic disorders such as hypothyroidism, obstructive liver disease, diabetes, and kidney disease