What is an Apolipoprotein B test?

An Apolipoprotein B (Apo B) blood test provides deeper insights into your risk of cardiovascular disease. It isn’t routinely offered in the UK and is usually requested by specialist healthcare professionals when a more accurate assessment of heart health is needed.

This guide explains what an Apolipoprotein B test measures, when it is typically used, what your results may indicate, and how it differs from an Apolipoprotein A test.

What is an Apolipoprotein?

Apolipoproteins are proteins that attach to fats (lipids) to form lipoproteins. Their main role is to transport lipids around the body. They also support enzyme activity, maintain the structure of lipoproteins, and help regulate lipid metabolism.

What is an Apolipoprotein B test?

An Apolipoprotein B test measures the amount of Apo B in your blood. There are two forms:

• Apo B-100 – made in the liver

• Apo B-48 – produced in the small intestine

A standard Apo B test measures Apo B-100, which binds to LDL and VLDL particles - the lipoproteins often referred to as “bad cholesterol”. Because each Apo B molecule carries one LDL particle, Apo B offers a direct count of the number of potentially harmful lipoproteins in the blood.

Research suggests Apo B can predict heart and blood vessel disease risk more accurately than a standard cholesterol panel. It may also help identify the cause of high cholesterol and monitor the response to lipid-lowering treatments.

When is an Apolipoprotein B test used?

Apo B testing is typically requested when:

• You have a family history of heart disease

• Previous tests show elevated cholesterol or triglycerides

• A clinician needs more accurate information about cardiovascular risk

• Your healthcare provider is monitoring response to cholesterol-lowering treatment

Because Apo B is a specialist, non-routine test in the UK, it’s usually recommended by cardiologists and lipid specialists.

Apolipoprotein B vs Apolipoprotein A

Both tests provide insights into cardiovascular health, but they measure different proteins:

Apolipoprotein B (Apo B)

• Found on LDL and VLDL particles (bad cholesterol)

• Higher results indicate a higher risk of heart disease

Apolipoprotein A (Apo A0

• Found on HDL particles (good cholesterol)

• Higher results indicate higher HDL levels and a lower risk of heart disease

Checking both together can provide a clearer picture of your overall lipid profile.

What are normal Apolipoprotein B levels?

A typical Apo B reference range is 40-120 mg/dL.

Results above these ranges may indicate an increased risk of cardiovascular disease.

What can increase your Apo B levels?

Apo B levels may rise if you:

• Have high cholesterol

• Are pregnant

• Have nephrotic syndrome or certain kidney conditions

What can reduce your Apo B levels?

Apo B levels may be lower if you have:

• Liver disease

• Sepsis

Levels can also fall if you are taking oestrogen medication.

What happens if my Apo B result is abnormal?

If your Apo B level is higher than expected, your healthcare provider may recommend lifestyle changes similar to those advised for high LDL cholesterol, such as:

• Increasing daily physical activity

• Eating more fruit and vegetables

• Reducing saturated fat intake

• Maintaining a healthy weight

• Stopping smoking

• Considering cholesterol-lowering medication such as statins, if advised

FAQs

Do I need to fast before an Apolipoprotein B test?

Fasting isn't always required for an Apo B test, but some clinicians prefer a fasting sample to give a clearer picture of your overall lipid profile. Your appointment instructions will confirm whether fasting is needed.

Is an Apolipoprotein B test better than a standard cholesterol test?

Apo B can provide more precise information because it directly counts the number of potentially harmful lipoprotein particles. Many specialists consider it a useful addition when assessing cardiovascular risk alongside standard cholesterol checks.

Can I improve my Apo B levels naturally?

Lifestyle changes such as regular exercise, increasing fruit and vegetable intake, reducing saturated fat, and stopping smoking can help support healthy Apo B levels. Your healthcare professional may also discuss medication if needed.

How quickly will I receive my results?

After your appointment, you’ll receive your personalised digital Results Report in around eight days. Your report will also explain what your Apo B levels mean and whether further checks are recommended.

Take a proactive approach to cardiovascular health with Bluecrest Wellness

If you’d like deeper insights into your heart health, our private health checks are a convenient way to access a more complete picture.

Our full body health MOTs include a wide range of blood tests, including cholesterol and diabetes checks, liver and kidney assessments, and markers linked to cardiovascular health. With over 350 venues across the UK, it’s easy to access fast, accurate private blood testing at a time that suits you.

You’ll receive your personalised results digitally in around eight days, plus access to our 24/7 GP Helpline for a full year.

BOOK NOW

Need help? Call free on 0800 652 2183 to speak to one of our team.