Is ApoB Testing Worth It?
ApoB is the superior marker for cardiovascular risk. It counts particles, not cargo—and particles are what matter. With 10-20% of people having "normal" LDL but elevated particle numbers, this test reveals risk that standard cholesterol testing misses.
9 of 9
studies show ApoB outperforms LDL cholesterol for predicting cardiovascular events
Source: [1]
The Short Answer
Yes—ApoB is superior. ApoB is the superior marker for cardiovascular risk assessment. The European Atherosclerosis Society now recommends it as the preferred lipid target over LDL cholesterol. ApoB directly counts all atherogenic particles in your blood, whilst LDL-C only estimates cholesterol content. In 10-20% of people, these markers disagree—and when they do, ApoB is the better predictor. The challenge: it's not covered by Medicare, many Australian GPs aren't familiar with it, and clinical pathways are still developing. But if you want accurate risk assessment—especially with metabolic syndrome, elevated triglycerides, or family history—ApoB is the test that matters.[1][2]
What Is ApoB?
Apolipoprotein B (ApoB) is a protein on the surface of every atherogenic (plaque-causing) particle in your blood. This includes LDL, VLDL, IDL, and Lp(a)—all the lipoproteins that contribute to cardiovascular disease.[2]
The critical insight: there is exactly one ApoB molecule per particle. Measuring ApoB gives you a direct count of all particles capable of building arterial plaque.
LDL cholesterol measures cargo—how much cholesterol particles are carrying. ApoB counts vehicles—how many particles are on the road. And it's the number of vehicles, not the cargo, that determines risk.[1]
Why Particles Matter More Than Cargo
The Highway Analogy
Your bloodstream is a highway. Cholesterol travels in vehicles called lipoproteins.
- LDL-C measures cargo (total cholesterol on the road)
- ApoB counts vehicles (how many trucks are making deliveries)
Two people with identical LDL-C can have vastly different particle counts:
- Person A: 1,000 large particles, each heavily loaded with cholesterol
- Person B: 2,000 small particles, each carrying less cholesterol
Same total cargo. Twice the traffic. Person B has double the cardiovascular risk.[2]
More particles = more opportunities for those particles to penetrate artery walls and form plaque. This is why particle number is the superior predictor.
ApoB Is Superior: The Evidence
The evidence is no longer debatable. ApoB outperforms LDL cholesterol in every major study:
LDL Cholesterol (LDL-C)
- Measures cholesterol content only
- Usually estimated via calculation
- Inaccurate when triglycerides >1.7 mmol/L
- Misses VLDL, IDL, and Lp(a) contribution
- Standard of care but inferior predictor[1]
- Medicare-covered in Australia
ApoB
- Counts all atherogenic particles directly
- Superior predictor in 9 of 9 studies[1]
- Directly measured (not calculated)
- Accurate at any triglyceride level
- Captures LDL + VLDL + IDL + Lp(a)
- Not Medicare-covered (~$30-50)
International Guidelines Now Prefer ApoB
European Atherosclerosis Society (2025): "ApoB is recommended as the primary target for lipid-lowering therapy." The ESC/EAS guidelines now prioritise ApoB, particularly in patients with elevated triglycerides, diabetes, or metabolic syndrome.[1]
National Lipid Association (2024): "ApoB has been shown to be superior to LDL-C in risk assessment both before and during treatment with lipid-lowering therapy."[5]
Australian Guidelines: The Heart Foundation and RACGP are developing updated lipid guidelines. Current Australian practice still focuses on LDL-C, though this will likely change as international evidence accumulates.[6]
When LDL and ApoB Disagree
10-20% Have Discordant Results
In approximately 10-20% of people, LDL-C and ApoB tell different stories:[3]
- "Normal" LDL but elevated ApoB: Many small, cholesterol-depleted particles. Higher risk than LDL suggests.
- Elevated LDL but normal ApoB: Fewer, larger particles carrying more cholesterol each. Lower risk than LDL suggests.
A 2025 UK Biobank study of 41,099 participants found that even at just 2% discordance, cardiovascular risk was already elevated. At 30% discordance, hazard ratios reached 2.5x for coronary artery disease.[4]
When discordant, ApoB is always the better predictor. This is why European guidelines now recommend ApoB as the preferred marker.[1]
The Triglyceride Problem
LDL Is Usually Calculated—And Often Wrong
LDL cholesterol is rarely measured directly. It's usually calculated using the Friedewald equation from your total cholesterol, HDL, and triglycerides.
The problem? This calculation assumes a fixed ratio that breaks down when triglycerides are elevated:[7]
- Triglycerides 1.7-2.3 mmol/L: LDL underestimated by ~9 mg/dL
- Triglycerides 2.3-4.5 mmol/L: LDL underestimated by ~18 mg/dL
- Triglycerides >4.5 mmol/L: Calculation unreliable
"The Friedewald equation tends to underestimate LDL-C most when accuracy is most crucial," notes Johns Hopkins researcher Dr Seth Martin. Patients with high triglycerides may receive falsely reassuring "normal" LDL results whilst their actual risk is elevated.[7]
ApoB is directly measured—no calculation, no assumptions, no triglyceride interference.
Understanding Your Results
ApoB is reported in mg/dL or g/L. Here's how to interpret results based on international guidelines:[1][5]
Target for those with existing cardiovascular disease, diabetes, or very high calculated risk. Associated with lowest event rates.
Target for moderate-risk individuals. Many preventive cardiologists aim for this range proactively.
Generally acceptable for those without cardiovascular risk factors. Still below population average.
Higher than optimal. Discuss with your health practitioner, particularly if other risk factors are present.
Associated with increased cardiovascular risk. Your health practitioner will discuss management options.
NLA Target Recommendations (2024)
The National Lipid Association's Expert Consensus proposes stratified ApoB targets:[5]
- Intermediate risk: <90 mg/dL
- High risk: <70 mg/dL
- Very high risk: <60 mg/dL
Note: Australian guidelines don't yet specify ApoB targets. Your health practitioner will interpret results in the context of your overall cardiovascular risk profile.
Who Benefits Most?
ApoB testing provides superior risk assessment for everyone—but offers greatest value when LDL-C is most likely to mislead:
| Risk Factor | Why It Matters |
|---|---|
| These conditions cause small, dense LDL particles. ApoB often elevated despite 'normal' LDL-C. Discordance extremely common. Highest yield testing scenario. | |
| Friedewald equation underestimates LDL-C. ApoB provides accurate particle count regardless of triglyceride level. Most likely to benefit from testing. | |
| Diabetic dyslipidaemia typically features small, dense LDL. European guidelines specifically recommend ApoB in diabetes. LDL-C often misleading. | |
| Especially if family members had events with 'normal' cholesterol. May indicate inherited particle phenotype that LDL-C misses. | |
| To assess residual risk and verify treatment targets are truly achieved. ApoB is superior to LDL-C during treatment.[5] | |
Why GPs Don't Order It
Guidelines Lag Research
Australian guidelines still focus on LDL-C targets. Whilst European and American guidelines now recommend ApoB, local RACGP practice guidelines haven't caught up yet.
No Medicare Rebate
ApoB testing isn't covered by Medicare, meaning out-of-pocket costs ($30-50). GPs are understandably hesitant to order tests patients must pay for.
Education Gap
Most GPs trained on LDL-C targets. ApoB wasn't part of their education, and many don't know optimal targets or how to incorporate results into management.
Workflow Inertia
LDL-C pathways are established—clear targets, Medicare coverage, familiar management protocols. Changing to ApoB-based management requires system-wide shifts.
GP vs Functional Medicine Perspectives
Standard GP Approach
- Focus on LDL-C as primary target
- Use 10-year CVD risk calculators (Framingham/SCORE)
- Treat if absolute risk exceeds threshold
- May not be familiar with ApoB targets
- Follow RACGP/Heart Foundation guidelines
Functional/Preventive Medicine
- ApoB as preferred lipid marker
- Focus on lifetime risk, not just 10-year
- Lower treatment thresholds (ApoB <70-80)
- Advanced testing: Lp(a), particle size, hs-CRP
- Follow ESC/EAS and NLA guidelines
Function Health and Similar Services
Services like Function Health in the US include ApoB as standard—alongside Lp(a), hs-CRP, and fasting insulin. Their approach reflects the growing international consensus that standard cholesterol testing misses important cardiovascular risk factors.
As Function Health notes: "Up to 17.5% of people have dangerously high ApoB levels despite normal cholesterol tests." This isn't fringe medicine—it's based on the same European guidelines now being adopted worldwide.[8]
In Australia, similar advanced lipid testing is available through preventive cardiologists and direct-to-consumer services like Clarity Labs.
Is It Worth It?
✗ Probably Skip If...
- You're satisfied with standard testing and trust LDL-C as your risk marker
- Cost is a significant concern (not Medicare-covered, ~$30-50)
- Your GP isn't supportive and you don't want to advocate for yourself
- You prefer to rely solely on established Australian guidelines
✓ Worth Considering If...
- Metabolic syndrome, insulin resistance, or type 2 diabetes—highest yield scenario[1]
- Elevated triglycerides (>1.7 mmol/L) where LDL calculation is unreliable[7]
- Family history of early heart disease, especially with 'normal' cholesterol
- You want the most accurate cardiovascular risk assessment available[2]
- You're on statin therapy and want to verify residual particle-level risk[5]
- You're working with a preventive cardiologist or functional medicine practitioner
The Bottom Line
ApoB is the superior marker for cardiovascular risk. The evidence is unambiguous.
Nine of nine studies show ApoB outperforms LDL cholesterol for predicting cardiovascular events. The European Atherosclerosis Society now recommends it as the preferred lipid target. The National Lipid Association's expert consensus confirms it's superior both before and during treatment.[1][5]
For 10-20% of people, LDL-C and ApoB disagree—and when they do, ApoB is always the better predictor. This is particularly true if you have metabolic syndrome, elevated triglycerides, diabetes, or family history of heart disease. In these situations, LDL-C often provides false reassurance whilst ApoB reveals the true risk.
The challenge is practical, not scientific:
- Medicare doesn't cover it (~$30-50 out-of-pocket)
- Many Australian GPs aren't familiar with ApoB targets or management pathways
- Australian guidelines haven't caught up with international evidence
- You may need to advocate for yourself or work with a preventive cardiologist
If you're serious about cardiovascular optimisation, ApoB is the test that matters. It provides genuinely superior risk information. The science is clear. The barriers are systemic.
For those satisfied with standard care, a lipid panel with calculated non-HDL cholesterol remains a reasonable, Medicare-covered approach. But understand what you're accepting: an inferior marker that misses risk in 10-20% of people.
Discuss with your health practitioner to determine what's right for your situation.
Frequently Asked Questions
Disclaimer:This information is educational only and not medical advice. Results should be interpreted by your health practitioner in the context of your symptoms and health history. Treatment decisions should be made with your doctor or specialist.