Why Apolipoprotein B testing is important for heart health

Why Apolipoprotein B testing is important for heart health as shown by diagram of LDL molecule

Traditionally, low-density lipoprotein cholesterol (LDL-C), the so-called “bad cholesterol,” has been used as a primary indicator of cardiovascular disease (CVD) risk. However, recent advancements have revealed a more accurate measure: apolipoprotein B (ApoB).

What is apolipoprotein B and why is it important to measure?

ApoB is a protein component of LDL particles. In simple terms, it’s the shell that carries cholesterol within your bloodstream. A higher ApoB level indicates a greater number of LDL particles circulating in your blood, which significantly increases your risk of CVD.

Research shows that heart disease risk is driven by the number and type of cholesterol particles in the blood — and not so much by the amount of cholesterol itself. Unlike LDL, which only reflects the cholesterol content within LDL particles, ApoB directly measures the number of LDL particles themselves. ApoB testing offers a clearer picture of your heart disease risk by directly measuring the quantity of LDL particles.

Who should get ApoB tested?

In many people, ApoB and LDL cholesterol track fairly closely. However, occasionally some people have a normal amount of LDL cholesterol but a high concentration of ApoB particles, putting them at greater risk. Research has shown that LDL-C levels alone can underestimate CVD risk in individuals with elevated triglycerides and metabolic disorders (including abdominal obesity, diabetes, and high blood pressure). These people may have an increased number of small, cholesterol-poor LDL particles – so their LDL cholesterol level can be low but the ApoB count of the particles is actually high.

While ApoB testing can be beneficial for everyone, it’s particularly recommended for individuals:

  • With a family history of CVD
  • With high total cholesterol or triglycerides
  • With existing risk factors for CVD, such as diabetes or obesity

A benefit of ApoB testing is that fasting is not required. Unlike LDL cholesterol testing, which often requires fasting, ApoB levels can be determined through a simple blood test, regardless of when you last ate.

If your physician doesn’t offer ApoB testing

The evidence supporting the use of ApoB testing has been mounting in the last few years, as summarized in a 2023 review. In 2019, the European Society of Cardiology and the European Atherosclerosis Society concluded that ApoB is a more accurate marker of cardiovascular risk than LDL‐C or non‐high‐density lipoprotein cholesterol. And four clinical trials published since 2021 supported this conclusion.

In the United States, though, you probably should not be surprised if you have never had this simple blood test. If you think ApoB testing might be beneficial in your case, talk to your physician about your healthcare concerns. Feel free to share the resources and information from this post. A heart specialist may also be able to assist,Young female doctor consulting with a older male patient and many larger testing labs offer the test direct to consumers. However, it’s important to discuss the results with a doctor to ensure proper interpretation and follow-up care.


Apolipoprotein B testing provides a valuable tool for assessing your risk of cardiovascular disease. By measuring the number of LDL particles in your blood, it offers a more accurate assessment compared to traditional LDL-C testing. If you’re concerned about your heart health, discuss ApoB testing with your doctor. Early detection and intervention are crucial for preventing CVD.

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