What is Apolipoprotein B?
Key Takeaways
Lipoproteins are created by the body in order to transport fatty substances, such as cholesterol, through the bloodstream.
Certain lipoproteins are associated with a higher risk for heart disease, while others are associated with a lower risk.
Both low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL) increase the risk of heart disease, because they keep fats like cholesterol in the bloodstream, where they can deposit into the walls of the arteries.
Apolipoprotein B, or ApoB, is a component of multiple different high-risk lipoproteins, including LDL and VLDL.
Measuring ApoB allows you to determine the number of LDL and VLDL particles in your bloodstream, providing a more accurate measurement of your heart disease risk than total LDL cholesterol.
For people whose ApoB levels are too high, lowering it may decrease your heart disease risk. Lifestyle changes are usually used first, with medications and/or supplements also being used in some cases.
In order to live a long and healthy life, it’s essential to reduce your risk of heart disease. Heart disease is the most common cause of death in Singapore, and it’s also a common cause of disability. Reducing your risk can help to improve both your lifespan and your healthspan – the number of years that you spend in good health.
The levels of certain substances in the blood, known as lipoproteins, have shown a strong association with a person’s risk for heart disease. Measuring the levels of various lipoproteins can determine your heart disease risk. It may also be helpful to measure specific apolipoproteins, which are components of lipoproteins.
A blood test for a particular apolipoprotein, known as Apolipoprotein B or simply ApoB, has been found in research to be one of the strongest predictors of a person’s heart disease risk. This article will explain what ApoB is and why it’s so strongly linked to heart disease. We’ll also explain how to get your levels tested and what to do if they’re abnormal.
Introduction to Lipoproteins
In order to function well, your body needs certain types of fats. One example is cholesterol, which is a crucial substance that’s used for constructing cell membranes as well as for making certain hormones. Every cell in your body needs some cholesterol in order to function.
Because cholesterol is a fatty substance, it doesn’t dissolve well in water. To carry it in your bloodstream, your body makes packages known as lipoproteins. The cholesterol is carried in the core of the lipoprotein, with a shell of proteins and phospholipids around it.
While cholesterol is essential, having too much of it in the bloodstream can cause health issues. Excess cholesterol tends to deposit into the walls of arteries throughout your body. This makes the arteries narrower and stiffer, which reduces blood flow through them and also increases the chances of blockage by a blood clot. This is how high cholesterol levels are associated with a higher risk for heart disease.
Certain lipoproteins, known as low-density lipoproteins or LDL, act to carry cholesterol out to the body’s tissues. When levels of LDL are high, excess cholesterol remains in the bloodstream and can form deposits in arteries. LDL is sometimes known as “bad cholesterol,” and increases the risk of heart disease.
Triglycerides are another type of fat that’s carried in the blood. These fats are used for energy by cells. They’re carried in very low-density lipoproteins, or VLDL. Much like cholesterol, excess triglycerides can also build up in your bloodstream and deposit into the walls of arteries. Because of this, high VLDL levels also increase your risk for heart disease.
By contrast, high-density lipoproteins, or HDL, act to gather up excess cholesterol and return it to the liver, where it can be processed and eliminated. This helps to prevent excess cholesterol from building up. HDL is sometimes known as “good cholesterol,” and it actually decreases the risk of heart disease.
How is Apolipoprotein B related to LDL?
Apolipoproteins are found on the surface of lipoproteins. They form part of the “packaging” that makes up the lipoprotein shell, which carries fats like cholesterol and triglycerides inside.
One specific type of apolipoprotein is known as Apolipoprotein B, or ApoB. ApoB is found in both VLDL and LDL particles (including in Lipoprotein(a), which is the most damaging type of LDL).
However, there’s no ApoB in HDL particles. Instead, HDL contains a different apolipoprotein, known as Apolipoprotein A1 or ApoA1.
Each particle of LDL or VLDL contains one molecule of ApoB. This means that measuring ApoB levels offers a way to count the number of LDL and VLDL particles in your blood. It’s an accurate measure of how many of these damaging types of lipoprotein particles your blood contains.
Why do you need to measure your Apolipoprotein B levels?
Many years of research have shown that testing ApoB gives a more accurate assessment of a person’s heart disease risk than measuring LDL cholesterol.
When you get an LDL test (such as on a standard lipid panel, which is generally included as part of your yearly doctor’s visit), this test measures the total cholesterol content contained within LDL in your blood. Although this is related to the number of LDL particles, it’s actually not the same as measuring the number of particles. The same total LDL cholesterol could indicate that you have fewer LDL particles, but each one is large and contains a lot of cholesterol – or that you have more particles, but each one is small and contains less cholesterol.
The number of LDL particles has been found to be more important than total LDL cholesterol in determining your heart disease risk. In fact, smaller LDL particles actually seem to be more dangerous than larger ones. They’re more easily able to penetrate into the walls of arteries and form deposits. Measuring total LDL cholesterol doesn’t give you a sense of whether your LDL particles are smaller or larger, so it can’t offer a full picture of your risk for heart disease.
People with insulin resistance or diabetes often have LDL particles that are smaller and denser than usual. As a result, testing their LDL cholesterol will tend to underestimate their true risk of heart disease. Testing ApoB offers a way to determine the total number of LDL particles, giving a more accurate sense of a person’s heart health.
Testing for Apolipoprotein B
Although ApoB is a better test for heart disease risk than LDL is, it’s still not always included as part of a standard set of labs, which usually includes only LDL and HDL levels. If you’d like to get the ApoB test, you’ll need to talk with a qualified physician who can order the test.
In order to get an ApoB test, you’ll need to have a blood draw in a medical laboratory. Fasting isn’t always required for this test, but if you’re also having other tests (such as a lipid panel), then you’ll need to fast before the test. This means that you don’t eat or drink anything other than water for about 8 to 12 hours before the test. The easiest way to do this is to visit the medical lab first thing in the morning for the test. Dress in short sleeves, so the veins in your arms will be easily accessible for the test.
After your blood is drawn, it usually takes a day or two for the test to be performed and the results to become available to both you and your doctor.
Factors Influencing ApoB Levels
There are many different factors that influence your levels of Apolipoprotein B. Some of the factors include:
Genetics. Some people’s bodies naturally produce more lipoprotein particles containing ApoB than others do. If you have a strong family history of heart disease (meaning that multiple relatives have had heart disease or a heart attack, particularly at relatively early ages), then you might have a genetic predisposition towards high ApoB levels.
Age. ApoB levels tend to increase as people get older. There’s a particularly sharp rise in women around the age of 50, which corresponds to the time of menopause.
Lifestyle choices. People who eat more saturated fats, trans fats, processed foods, and refined carbohydrates (such as white sugar) tend to have higher levels of both LDL cholesterol and ApoB. In addition, people who don’t get enough exercise have higher ApoB levels.
Chronic diseases. People with certain chronic diseases tend to have higher ApoB levels. One common example is type 2 diabetes, which is associated with increased ApoB levels. Chronic kidney disease can also increase the levels.
Medications. There are certain medications that are targeted to reduce LDL and ApoB. However, other medications can also have an impact. For example, estrogen therapy in postmenopausal women has been shown to decrease ApoB levels by 19%, and LDL levels by 26%.
How to Manage Elevated Apolipoprotein B Levels
If your ApoB levels are high, then taking steps to lower them may help to decrease your risk of heart disease. The first step is usually lifestyle interventions, which can make a significant difference in ApoB levels for many people. Some people benefit from supplements or prescription medications intended to lower ApoB levels.
Lifestyle interventions for lowering ApoB
Certain aspects of your lifestyle can have a significant impact on your ApoB levels. This includes eating a healthy diet. While nutrition is complex, just a few simple changes can often make a significant difference in a person’s ApoB levels and their risk for heart disease:
Reduce saturated fat. This type of fat is typically found in animal products like dairy products, butter, and red meat, as well as coconut and palm oils. A large number of research studies show that eating more saturated fat increases LDL cholesterol and ApoB levels. Try to replace saturated fat with healthier options. For example, use a plant-based oil (like olive oil or sesame oil) instead of butter, and choose chicken or tofu instead of beef.
Eat less fried food. The process of frying creates a type of fat known as trans fats. This is considered the worst type of fat in terms of your heart health, because it causes the largest increase in LDL cholesterol and ApoB levels. The more trans fats you eat, the higher your ApoB levels are likely to be. Choose foods that are baked or steamed rather than fried.
Replace processed foods with healthier snack options. Many packaged foods are also high in trans fats. These foods are also often high in starch, sugar, and calories. Instead of reaching for chips or cookies, choose healthier snack foods, like nuts or fruits.
Reduce sugar consumption. Research has found a link between consuming more processed sugar and higher LDL cholesterol and ApoB levels. In general, the less processed sugar you consume, the better. Replace sugary sodas with flavored water or herbal teas. Choose kopi o kosong instead of a sugary option.
Increase soluble fiber. Fiber is a type of carbohydrate that your body can’t digest. A particular type of fiber, known as soluble fiber, helps to bind cholesterol and keep it in your digestive tract, so your body doesn’t absorb it. Studies have shown that eating more soluble fiber can lower LDL cholesterol and ApoB levels. Soluble fiber is found in foods like apples, pears, and oats.
In addition to your diet, it’s important to consider your level of physical activity. Singapore’s Health Promotion Board recommends 150 to 300 minutes of moderate physical activity each week. This is an average of about 20 to 40 minutes each day, at the intensity of brisk walking (or greater). Make sure to build in time for exercise every day.
While getting enough physical activity is crucial, it’s not just your workouts that matter. Smaller movements that you make throughout the day – including walking around a store, doing housework, and even fidgeting – actually make a significant contribution to your overall energy expenditure. These movements are known as non-exercise activity thermogenesis, or NEAT.
You can increase your NEAT by finding small ways to get a little extra physical activity in your day. Examples include taking the stairs instead of the elevator, taking short walking breaks at work, and choosing to fidget more whenever you’re sitting. Each of these individual choices may seem small, but they add up to a significant increase in your physical activity level. Taking steps to increase your NEAT can therefore make a significant difference in your body weight and heart health, and can help to decrease your ApoB levels.
Medications and supplements for lowering ApoB
When lifestyle interventions are not enough to bring ApoB levels down to a healthy range, then additional treatments may be considered.
In some cases, prescription cholesterol-lowering medications are recommended. The most common type are known as statins, although there are also many other types available. These medications lower LDL, and because ApoB is a component of LDL, they will lower ApoB as well. In some cases, more than one medication is needed to bring ApoB levels into a healthy range.
Prescription medications can have side effects. You should talk with your doctor to decide whether the potential benefit of lowering your heart disease risk is worth the potential risk of experiencing side effects. If you do experience side effects, switching medications may help. In some cases, more than one medication is used together to get the desired results.
There are also supplements that can help to lower LDL cholesterol and ApoB levels. These generally have a smaller effect than prescription medications do, but some of them have been shown in research to be effective. One example is plant sterols, which have been found in studies to lower LDL cholesterol by up to 12%.
Managing your heart disease risk
If you’re interested in longevity, then it’s essential to pay attention to your heart disease risk. In Singapore, heart disease is one of the biggest threats to your lifespan and healthspan. Knowing your heart disease risk allows you to take steps to help protect yourself against this extremely common condition.
To get testing for ApoB, as well as other tests that can help you to gain a comprehensive understanding of your heart disease risk (such as the Lp(a) test), you’ll need to consult with a qualified physician. These tests must be ordered by a doctor, who will also help you to interpret the results and make a plan for how to address them.
Our NOVI Assessment Max clients receive a comprehensive panel of tests, including tests for heart disease risk as well as many other common health conditions. In addition to having their medical care managed by an expert physician, our clients also work with health coaches to help them develop and implement a healthy lifestyle plan that will work for them.