What does a lipid panel test for? The cholesterol story
Our body is made up of billions of smaller structures of four major kinds, including, cells, tissues, organs, and systems. These body’s structures are based on four major classes of biological macromolecules: nucleic acids, proteins, carbohydrates also known as glycans, and lipids, as well as their combinations. Glycoproteins (proteins + carbohydrates), glycolipids (lipids + carbohydrates), lipoproteins (lipids + proteins) are combinations that enable interactions among these macromolecules. Each is an important body structure component and performs a wide array of structure and function activities. Lipids are found in your blood and are stored in tissues. They are an important part of cells, and they help keep your body working normally. So, What does lipid panel test for? This blog covers the details about lipids panel test.
Lipids come in three forms -- fats, steroids, and phospholipids. The main functions of these lipids are energy storage—fats; chemical compounds for the synthesis of other molecules and signaling—steroids; and insulation—phospholipids have one side that like water (the phosphorous) and another side that is hydrophobic (do not like water, the lipid) that are arranged head-to-head and tail-to-tail to generate membranes that act as the cell fence. Cholesterol is the most common steroid and is the precursor (a chemical compound in a multi-step synthesis that acts as the previous step in the process) to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts. Lipid disorders, such as high cholesterol, may lead to life-threatening illnesses like coronary artery disease (CAD), heart attack, or stroke. Checking your lipids level is important to detect lipids disorders and prevent these risky diseases.
What Is a Lipoprotein?
Your liver makes cholesterol, and it is also in some foods, such as meat and dairy products. Triglycerides are a type of fat. They are the most common type of fat in your body that is based on extra calories (the calories you eat but your body does not need). As fatty molecules, cholesterol and triglycerides do not circulate well in your bloodstream, which is mainly water-based. In order for cholesterol and triglycerides to travel in your blood, they are often carried by proteins that make the cholesterol and triglycerides more soluble in the blood. This lipid + protein complex is called a lipoprotein.
Lipids Panel Test
There are five different types of lipoproteins in our blood, and they are commonly classified according to their density. Since lipids have a lower density than water (oil floats on the surface of the water), the density of lipoproteins depends on the ratio of lipid to protein. The main types of lipoproteins that are analyzed in a lipid panel include very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). The two others are the Intermediate density lipoproteins (IDL) which are less dense than LDL but denser than VLDL, and Chylomicrons - the least dense type of lipoprotein, which is based on triglycerides and a small amount of protein.
The main lipids in a lipid panel test are HDL cholesterol (the "good" cholesterol), LDL cholesterol (the "bad" cholesterol), Triglycerides, and Total cholesterol. Some lipid panel also includes the VLDL. Check on Fantestico analytes included, which lab provider includes the VLDL on their lipid panel. VLDL is made in the liver and is responsible for delivering triglycerides to cells in the body, which is needed for cellular processes. Once the triglycerides are delivered to cells, VLDL has less fat and more protein, with the same amount of cholesterol, so eventually, it becomes an LDL cholesterol.
What makes HDL cholesterol “GOOD”?
The HDL cholesterol consists of the lowest amount of cholesterol and more protein in comparison to all other lipoproteins. It is made by the liver and in the intestines. It carries cholesterol from the cells back to the liver. Less cholesterol in the cells is better for your health, so this function makes the HDL cholesterol good.
Why LDL cholesterol is “BAD”?
The LDL cholesterol consists of more cholesterol than triglycerides and protein and it is responsible for carrying cholesterol to cells that need it. When you have a high level of LDL cholesterol, it means too much cholesterol is sent to your cells, leading to Atherosclerosis, which is the build-up of fats, cholesterol, and other substances in and on your artery walls. This build-up is called plaque. The plaque can cause your arteries to narrow, blocking blood flow. The plaque can also burst, leading to a blood clot. Healthy arteries are flexible and elastic, but over time, the walls in your arteries can harden. When your arteries become thick and stiff, which can reduce the blood flow to your organs. This is called Arteriosclerosis. Atherosclerosis is a specific type of arteriosclerosis and is caused by the build-up of these plaques.
Cholesterol Ratio
The cholesterol ratio is calculated by dividing your total cholesterol number by your HDL cholesterol. For example, if your total cholesterol number is 200 and your good cholesterol is 50, your cholesterol ratio is 4:1. The normal cholesterol ratio is 5 or below, while the optimal ratio is between 3.5 and 1. A cholesterol ratio within the normal range means that your cholesterol levels are less likely to contribute to cardiac risk.
LDL/HDL Ratio
A lipid panel with ratios may also include the calculated LDL/HDL ratio. The LDL/HDL ratio appears to be as useful as the total/HDL cholesterol ratio. Their similarity can be explained by the fact that approximately two-thirds of cholesterol in the plasma (the non-cell part of your blood) is found in LDL and, therefore, the total and LDL cholesterol are closely related.
Lipid panel with Non-HDL Cholesterol
In general, the higher your total and LDL cholesterol levels, the higher your risk for coronary heart disease. But some heart attacks happen in people who don't have a high LDL level. Measuring your non-HDL cholesterol levels can give a better assessment of the risk for heart disease than only your LDL levels, especially if you have high triglycerides. Your non-HDL cholesterol level is found by subtracting your HDL cholesterol from your total cholesterol. High non-HDL cholesterol means that you are at risk for cardiac events. Many doctors believe that monitoring your non-HDL cholesterol level may be more useful than calculating your cholesterol ratio or the LDL/HDL ratio. Either option is considered a better risk predictor than just measuring your total cholesterol level or even your low-density lipoprotein (LDL, "bad") cholesterol level.
Lipid panel with reflex to direct LDL
The Lipid Panel with reflex to LDL Cholesterol Direct includes all components in the regular lipid panel but will automatically use your blood sample (reflexes) to measure your LDL Cholesterol Direct if Triglycerides are higher than 400 but lower than 1250. Direct measurement of the LDL cholesterol is more accurate than the typical calculated LDL.
At What age should I get screened for lipids?
The center for disease control and prevention (CDC) recommends that people age 20 or older who are at low risk should test their lipids every 5 years and more often for those with cardiovascular disease risk factors1. This is because 20% of adults have an unhealthy cholesterol reading and nearly 93 million U.S. adults age 20 or older have high cholesterol. But since high cholesterol doesn’t have symptoms, many people don’t know their levels are high1.
Can I order a lipids panel test online?
Yes. Many lab providers are offering direct to consumers lipid panel tests that can be purchased online without a doctor. Some require an in-person visit to your local lab for a blood draw and many are sending blood collection kits to your home. Many of these at-home lipid panel test kits are accurate. In most cases, you’d need to fast for 10 to12 hours before your lipid panel blood test. Always follow the instructions that your lab provider gives you.
What are normal levels of cholesterol?
Normal levels of total cholesterol, non-HDL, LDL, and HDL depend on your age and sex. The following table shows the current guidleines2:
| Age and Sex | Total cholesterol | Non-HDL cholesterol | LDL cholesterol | HDL cholesterol |
|---|---|---|---|---|
| People 19 years and younger |
Less than 170 mg/dL |
Less than 120 mg/dL |
Less than 110 mg/dL |
More than 45 mg/dL |
| Female 20 years and older |
125 mg/dL to 200 mg/dL |
Less than 130 mg/dL |
Less than 100 mg/dL |
50 mg/dL or higher |
| Male 20 years and older |
125 mg/dL to 200 mg/dL |
Less than 130 mg/dL |
Less than 100 mg/dL |
40 mg/dL or higher |
What is considered as higher than normal?
High cholesterol risk levels vary by age group and sex and are different for those who have heart disease. Some people with a family history of heart disease are using these numbers as their risk levels.
The following table shows the current guidleines2:
| Age and Sex | Total cholesterol | Non-HDL cholesterol | LDL cholesterol |
|---|---|---|---|
| People 19 years and younger,
including children and teens
|
Borderline: 170-199 mg/dL High: Greater than or equal to 200 mg/dL |
Borderline: 120-144 mg/dL High: Greater than or equal to 145 mg/dL |
Borderline: 110-129 mg/dL High: Greater than or equal to 130 mg/dL |
| Female 20 years and older |
Borderline: 200-239 mg/dL High: Greater than or equal to 239 mg/dL |
High: Greater than 130 mg/dL |
Near optimal or above optimal: 100-129 mg/dL Borderline: 130-159 mg/dL High: 160-189 mg/dL Very high: Greater than 189 mg/dL |
| Male 20 years and older |
Borderline: 200-239 mg/dL/dL Borderline: 200-239 mg/dL/dL |
High: Greater than 130 mg/dL |
Near optimal or above optimal: 100-129 mg/dL Borderline high: 130-159 mg/dL High: 160-189 mg/dL Very high: Greater than 189 mg/dL |
What should I do if I have abnormal lipid panel levels?
If your lipid panel blood work levels are high/low than the guidelines, it doesn’t necessarily mean that you have a medical condition or need treatment. It means that you need to consult with your healthcare provider who will take into consideration additional factors like your overall health, medical history, any medication you are taking, and other risk factors like smoking, overweight, high blood pressure, having diabetes or being prediabetic, family history of cardiovascular diseases in a first-degree relative at a relatively young age (under 65 for females and under 55 for males). Do not ignore it. Sometimes, a diet change and excursion can reverse your lipids panel test results. If you have questions about your numbers, don’t be afraid to discuss them with your healthcare provider. Your lipids are a long-term game and may require constant management.
Conclusion
A lipid panel is a blood test that measures the level of certain lipids in your blood. It is a simple way to monitor your risk of cardiovascular problems like heart disease, heart attack, and stroke. As every person’s health is different and many factors can contribute to the overall risk level, consult with your healthcare provider. Continued lipids monitoring, lifestyle change and sometimes starting cholesterol-lowering medication can put you back on track.
Do you remember when the last time you checked your lipids was?
1. https://www.cdc.gov/cholesterol/checked.htm
2. Scott M. Grundy, Neil J. Stone, Alison L. Bailey, Craig Beam, Kim K. Birtcher, Roger S. Blumenthal, Lynne T. Braun, Sarah de Ferranti, Joseph Faiella-Tommasino, Daniel E. Forman, Ronald Goldberg, Paul A. Heidenreich, Mark A. Hlatky, Daniel W. Jones, Donald Lloyd-Jones, Nuria Lopez-Pajares, Chiadi E. Ndumele, Carl E. Orringer, Carmen A. Peralta, Joseph J. Saseen, Sidney C. Smith Jr, Laurence Sperling, Salim S. Virani and Joseph Yeboah, AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, Circulation. 2019;139:e1082–e1143 https://doi.org/10.1161/CIR.0000000000000625