Heart disease is the leading cause of death for adults in the United States.
Most people have heard of cholesterol, especially low-density lipoprotein cholesterol (LDL-C), often called “bad cholesterol.” But there’s another marker that may give a clearer picture of your heart health: apolipoprotein B (ApoB). So, what is ApoB and is it a better predictor of heart disease than LDL-C?
Understanding LDL-C and ApoB: What do they measure?
Cholesterol is a waxy substance that your body needs in small amounts to build cell membranes, produce hormones and perform other key functions. Although there are different types of cholesterol, the word is typically used to refer to the kind that can increase the risk of heart disease. Too much cholesterol in your blood can lead to plaque buildup in your arteries, a condition called atherosclerosis. This buildup can increase your risk of heart attack and stroke.
Cholesterol travels through your blood inside particles called lipoproteins. LDL-C measures how much cholesterol is being carried by LDL particles. But here’s the catch: LDL-C doesn’t tell you how many particles are doing the carrying.
This means two people could have the same LDL-C level, but one might have fewer, larger particles, while the other might have many small ones. The person with more particles may actually be at higher risk, even though their LDL-C number looks the same.
That’s where ApoB comes in. The apolipoprotein B protein is found on the surface of several types of risk-raising cholesterol-carrying particles including LDL and others. ApoB gives you a count of how many particles are in your blood that can contribute to plaque buildup.
Think of it like this:
- LDL-C tells you how much cargo is being carried
- ApoB tells you how many trucks are on the road
Even if each truck isn’t overloaded (with cholesterol), having more trucks (particles) on the road means more chances for traffic jams in the artery highways.
Why ApoB may be a stronger predictor of heart disease
Recent research from the American Heart Association shows that ApoB has a stronger link to atherosclerotic cardiovascular disease (ASCVD) than LDL-C. That’s because ApoB measures all the particles that can cause damage, not just the cholesterol inside them.
Normal LDL-C doesn’t guarantee low risk. Some people with normal LDL-C levels may still be at risk for heart disease, and ApoB has the potential to uncover hidden heart disease risk. This is especially true for people with:
- Insulin resistance
- Type 2 diabetes
- Metabolic syndrome
In these cases, the number of cholesterol-carrying particles are more likely to be high, even when the cholesterol itself isn’t. That’s why ApoB can be a more accurate way to assess heart risk.
How you can check your heart disease risk
If you’re curious about your heart health, getting tested is a great first step. Labcorp OnDemand offers the Comprehensive Heart Health Test, which provides an in-depth look at key markers to help you understand your overall cardiovascular risk.
Prefer to focus on specific areas? You can also choose from individual tests like:
- ApoB Test – ApoB identifies the number of atherogenic or risk-enhancing cholesterol-carrying particles in the blood (because not all cholesterol is atherogenic/risk-enhancing, HDL for example)
- Cholesterol and Lipid Panel – to check your LDL-C and other cholesterol levels
- Lipoprotein(a) Test – for more insight into inherited heart risk
These tests can help you and your healthcare provider understand your cardiovascular risk more clearly. Remember: these tests don’t diagnose heart disease, but they can provide helpful insights for prevention and early action.
Understanding your results and identifying risks early can spark helpful conversations about lifestyle changes or treatment options to protect your long-term heart health.
Lab tests like ApoB and LDL-C are tools to help assess risk. They do not diagnose heart disease. Always consult with a healthcare provider to interpret your results and decide on the best next steps.
