How to Read a Lipid Profile
As we age, one of the most common screening tests, to assist in evaluating heart health, is a cholesterol test, also called a “lipid panel.” Most people understand the basics when it comes to interpreting the results of cholesterol tests, such as good and bad cholesterol values. But, some of the medical terms can be confusing.
Learn more about how to read a lipid profile.
Let’s start with the basics. What is cholesterol? Cholesterol is a waxy substance the liver makes by changing the fats (lipids) and sugars (carbohydrates) that we ingest in our diet, into various types of cholesterol, including HDL, LDL and various other types of cholesterol. This cholesterol circulates in our bloodstream. Even if you don’t eat foods with a lot of fat content, your body can still make cholesterol by converting carbohydrates (from starches and sugars) into fats.
The liver produces and regulates cholesterol in the body, preparing it for transport to hormones and cells. The liver also removes excess cholesterol. Cholesterol is insoluble, meaning it cannot be dissolved in the blood to be transported because it is fat based (much like if you tried to mix Crisco with water). So, the body enfolds the cholesterol in something called a “lipoprotein.” Low-density lipoprotein, or LDL, is slightly less dense and it is used to transport the cholesterol from the liver to the cells throughout the body. HDL or high-density lipoproteins are more complex than other lipoprotein species, containing more protein than LDL. This helps to facilitate cholesterol secretion from cells, so the body can transfer cholesterol to other lipoproteins and to the liver to be excreted.
The LDL is commonly known as “bad” cholesterol. This is the type that clogs up the blood vessels and can lead to a high risk of a heart attack or stroke. Another type of cholesterol on the lipid panel is the HDL cholesterol. HDL is commonly referred to as “good” cholesterol because it helps lower the LDL (bad cholesterol). But, there are several other lab value results on a cholesterol test.
Is Your Cholesterol Good or Bad?
So, now that you understand just what HDL and LDL really are, why, exactly, are these lipids considered good or bad?
LDL is associated with atherosclerosis, which is a condition in which lipids (combined with inflammatory cells) accumulate within the walls of the blood vessels — this is called plaques. Plaques cause the blood vessel to narrow, which may result in clots that interfere with the blood flow. This process inhibits the body’s normal oxygen delivery system (via the blood stream) and can lead to hypoxia (lack of oxygen) and death or injury to the tissue (which is what commonly occurs in a stroke or heart attack). In a stroke, the brain tissue is deprived of blood flow from a clot or blockage of the carotid arteries (those carrying blood from the heart, up through the sides of the neck and eventually to the brain). In a heart attack, coronary (heart) arteries that supply oxygen to the tissue in the heart, are blocked by atherosclerotic plaques.
HDL works to remove extra cholesterol from the walls of the arteries, removing atherosclerotic plaque, then the HDL takes the extra cholesterol back to the liver, to be broken down. In addition, HDL removes excess cholesterol from the cells of the body in a process known as reverse cholesterol transport.
Interpreting Lipid Panel Results
A lipid profile is a lab test (taken from a blood sample) that measures just how much cholesterol and triglycerides (and which types) are in the blood. This test gives the healthcare provider information on what’s going on in your blood when it comes cardiovascular health.
The measurements that are evaluated in a lipid panel (and how to interpret each result) include:
- High-density lipoprotein (HDL): Good cholesterol, the higher the number, the lower the risk of cardiovascular disease.
- Low-density lipoprotein (LDL): Bad cholesterol and a major contributor to atherosclerosis. The optimal level should be less than 100 mg/dL, If the LDL is over 190 mg/dL, the healthcare provider will usually prescribe a medication called “statins” to lower LDL.
- Total cholesterol: This result reveals an estimate of good HDL plus bad LDL; an overall higher cholesterol level may result from high levels of HDL (which is good) or high levels of LDL (not so good). Determining the breakdown of exactly which types of cholesterol comprise the total cholesterol level is important. Less than 200 mg/dL is good for a total cholesterol level. If this number is higher, it can be good or bad, depending on the breakdown of HDL and LDL. Note- Having a total cholesterol level over 240 mg/dL may double the risk of heart disease.
- Triglycerides: A type of fat carried in the blood from the food we eat. Triglycerides should be less than 150mg/dL (200 mg/dL or over is high, 500 mg/dL or over is very high)
Some cholesterol tests also include:
- Total cholesterol to HDL ratio: The amount of total cholesterol divided by HDL. This measurement helps useful doctors predict the risk of developing atherosclerosis.
- Very low-density lipoprotein (VLDL): An additional type of bad cholesterol that can build up inside the arteries, this type of cholesterol contains the highest level of triglycerides. From 5 mg/dL to 40 mg/dL is optimal, the higher the VLDL level, the higher the risk of heart attack or stroke.
The American Heart Association recommends getting a cholesterol level checked every four to six years once a person turns 20. Those who are high risk should be checked more often, according to the recommendation of their healthcare provider.
Keep in mind that normal levels in a lipid profile are just a basic guideline and that what is normal for one person, may not be normal for the next individual. The healthcare provider will help to interpret the cholesterol findings and give advice on the risk factors specific to each patient. The overall goal depends on several factors, including family history of heart disease, any additional risk factors for cardiovascular disease (such as diabetes, obesity or high blood pressure) and more.
Always consult with the healthcare provider to accurately interpret your lipid profile test results.