In short
- LDL cholesterol measures how much cholesterol sits inside your particles, ApoB counts how many risk-carrying particles there are.
- With high triglycerides, excess weight or type 2 diabetes, LDL and ApoB can diverge.
- Lp(a) is largely inherited and barely changes with lifestyle, so one measurement in your lifetime is usually enough.
- Without particular risk factors, a cholesterol profile usually tells you enough.
Why LDL alone is not the whole story
LDL cholesterol has been the value that receives the most attention in cardiovascular risk for decades, and not without reason. Yet that test measures something very specific: how much cholesterol sits inside your LDL particles. That is a measure of the cargo, not of the number of vehicles carrying it.
And it is the number of particles that determines how often a particle gets the chance to lodge in the vessel wall. That lodging is the start of the process that leads to atherosclerosis over decades.
In many people the two run neatly in parallel: plenty of cholesterol means plenty of particles. But not in everyone. People with high triglycerides, excess weight, insulin resistance or type 2 diabetes more often have smaller LDL particles that carry less cholesterol each. More of them are then needed to transport the same amount of cholesterol.
Your LDL can look reassuring in that case while the particle count is actually high. Doctors call this discordance, and it is exactly the situation in which an additional test makes a difference.
What ApoB counts: particles instead of cargo
Every particle that can carry cholesterol into the vessel wall holds exactly one molecule of apolipoprotein B. That applies to LDL, but also to VLDL, IDL and to Lp(a).
So when you measure ApoB, you are in effect adding up all those particles. You get a single number showing how many risk-carrying particles circulate in your blood, regardless of how much cholesterol sits inside each individual particle.
There is a practical advantage as well. In many laboratories LDL cholesterol is not measured directly but calculated with a formula in which triglycerides play a part. That calculation becomes less reliable the higher the triglycerides are, or when you are not fasting.
ApoB is measured directly and is far less sensitive to this. That makes ApoB especially valuable in people whose metabolic profile puts pressure on the LDL calculation.
Lp(a): a value you inherit from your parents
Lipoprotein(a), usually shortened to Lp(a), is an LDL-like particle with an extra protein attached to it. How high your Lp(a) is lies almost entirely in your genes. The level is more or less set at a young age and then stays remarkably stable for most of your life. Diet, exercise, weight loss and most cholesterol-lowering medicines change little about it.
That has a convenient consequence: as a rule, one measurement in your lifetime is enough. If your Lp(a) turns out to be raised, it counts as an independent risk factor for cardiovascular disease, separate from your LDL.
There is currently no standard treatment that lowers Lp(a) itself, although research into this is well under way. What the result does change is how firmly you and your doctor address the factors you can influence. It is also good reason to let parents, brothers, sisters or children know that it may run in the family.
| Test | What does it measure? | Changeable through lifestyle? |
|---|---|---|
| LDL cholesterol | The amount of cholesterol inside your LDL particles | Yes, it responds to diet, weight and exercise |
| ApoB | The number of particles that can carry cholesterol into the vessel wall | Yes, it responds to the same measures as LDL |
| Lp(a) | An LDL-like particle with an extra protein, largely inherited | Barely, the level is set almost entirely in your genes |
ApoB and Lp(a) in a single blood draw
The Heart & Vessels Extra package measures ApoB and Lp(a) in a single blood draw, as a deeper look beyond your cholesterol profile. Including doctor interpretation and a personal PDF report. Price excludes €29 blood draw fee, which is waived from €225.
Who are these tests relevant for?
Most of the benefit lies with people who have a family history. These situations stand out:
- A father, mother, brother or sister who had a heart attack or stroke at a relatively young age
- Known familial hypercholesterolaemia in the family
- A cholesterol value that stays high while you eat well and move enough
- Having already been through a heart or vascular problem yourself
- An unfavourable metabolic profile with high triglycerides, excess weight or diabetes
In those cases ApoB gives a sharper picture than LDL alone.
If you have no particular risk factors and a settled cholesterol profile, ApoB and Lp(a) usually add little. In that case simply start with the basics. A cholesterol profile with total cholesterol, LDL, HDL and triglycerides then gives you the answer you are looking for, and it is also the measurement you can repeat later to see any effect.
Measuring more is not automatically better, certainly not when an extra result changes nothing about what you are going to do.
Lifestyle versus heredity
Heredity determines your starting point, lifestyle determines how fast the process runs from there. ApoB responds to the same measures as LDL:
- Replacing saturated fat with unsaturated fat
- More fibre from vegetables, fruit, pulses and wholegrain products
- Losing weight if you carry too much
- Exercising regularly
- Stopping smoking
Triglycerides, and with them the particle count, also respond strongly to alcohol and sugary drinks. Lp(a) stays almost entirely unmoved by all this, and that is no reason to throw in the towel. With a raised Lp(a), every bit of ground you gain on your ApoB, blood pressure and blood sugar counts for more.
If you want to know whether your adjustments are working, plan a repeat of your cholesterol profile and ApoB after a few months. Your Lp(a) does not need testing again.
When a blood test is not the answer
If you have complaints right now that could point to an acute problem, such as pressing chest pain, sudden breathlessness or loss of speech or strength, do not wait for a blood result. Call your GP or the emergency number. A blood test maps risk, it does not assess an acute situation.
It is also worth knowing that ApoB and Lp(a) say something about the chance of damage, but nothing about the state of your vessels right now. Other examinations are needed for that, requested by your GP or cardiologist. And your risk consists of more than blood values alone: blood pressure, smoking, weight, exercise and family history weigh at least as heavily.
Frequently asked questions
What is the difference between LDL cholesterol and ApoB?
LDL cholesterol reflects how much cholesterol sits inside your LDL particles. ApoB counts how many particles there are that can carry cholesterol into the vessel wall. In most people both point the same way. When they diverge, for example with high triglycerides, ApoB usually gives the sharper picture.
Do I need to fast for ApoB and Lp(a)?
For both tests fasting is usually not necessary. If your triglyceride value is measured in the same draw, a fasting sample may still be requested. So always follow the instruction you receive when booking your appointment.
How often should I have Lp(a) measured?
As a rule one measurement in your lifetime is enough, because the value is almost entirely determined by heredity and barely changes. Only if your doctor sees reason for it in your situation, for example because of new information from your family, can a second measurement be useful.
Can I lower my Lp(a) with diet or exercise?
Barely. Lp(a) takes little notice of your diet, your weight or your training schedule. That does not mean lifestyle is irrelevant. With a raised Lp(a) it is all the more important to keep your other risk factors as favourable as possible.
Do I need a referral for ApoB and Lp(a)?
No. At Bloodworks you have ApoB and Lp(a) tested without a referral, at one of the more than 750 affiliated collection points in the Netherlands. Your result is reviewed by a doctor and you receive a personal PDF report, typically within 2 working days.