Genetic Heart Risk Marker

Lipoprotein(a) / Lp(a) Explained

Your inherited heart-risk marker — what it is, the two unit systems that cause confusion, what you can and cannot do about it, and why you only need to measure it once.

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This page explains Lipoprotein(a) in an Australian context. It is educational only — not a diagnosis or treatment recommendation. Talk to your GP or cardiologist about what an elevated Lp(a) means for your personal cardiovascular risk management plan.

The Quick Answer

Lp(a) (spoken as "L-P-little-a") is a lipoprotein that looks very similar to LDL cholesterol, except it has an extra protein tail — apolipoprotein(a) — strapped on the outside. This tail makes Lp(a) both atherogenic (it drives plaque buildup in arteries) and thrombogenic (it promotes blood clotting), which is why elevated Lp(a) independently raises the risk of heart attack, stroke, and aortic valve disease.

The critical thing to understand is that Lp(a) is almost entirely genetically determined. Diet, exercise, and most medications barely move it. This is both sobering and clarifying: if your Lp(a) is high, that is information about your inherited risk architecture, not a lifestyle failure. It means you need to be more aggressive about the risk factors you can control.

Approximately 1 in 5 Australians carry Lp(a) above the threshold associated with significantly elevated cardiovascular risk. Because it is genetic, a single measurement in adulthood is usually all you need.

Optimal: below 75 nmol/L

Borderline: 75-125 nmol/L

Elevated: 125-200 nmol/L

Very high: above 200 nmol/L

The Two Units of Lp(a) — A Common Source of Confusion

Lp(a) can be reported in mass (g/L or mg/dL) or molar (nmol/L) units. The numbers look completely different, and you cannot simply compare them. Always note which unit your lab used, and use that unit consistently for follow-up tests.

nmol/L (molar)

Preferred

Normal: Below 75-100 nmol/L

Elevated: 100-200 nmol/L

High risk: Above 200 nmol/L

Internationally preferred. Measures particle number directly. Not affected by the size variation of apolipoprotein(a) isoforms, which is why it gives a more accurate cardiovascular risk estimate than mass-based units.

g/L (mass)

Normal: Below 0.3-0.5 g/L

Elevated: 0.5-1.0 g/L

High risk: Above 1.0 g/L

Still reported by many Australian labs. Conversion to nmol/L is not straightforward because apolipoprotein(a) comes in different sizes (isoforms) - a larger isoform gives a higher mass reading for the same number of particles. Always record which unit was used.

mg/dL (mass, US)

Normal: Below 30-50 mg/dL

Elevated: 50-100 mg/dL

High risk: Above 100 mg/dL

Used in the United States and some older Australian reports. To convert mg/dL to g/L, divide by 100. Do not compare mg/dL results with nmol/L results directly - they measure different things.

Important: There is no reliable conversion formula between nmol/L and g/L because the apolipoprotein(a) protein comes in different sizes (isoforms) between individuals. A large-isoform carrier may have a high g/L reading but a low nmol/L count — and lower cardiovascular risk than the g/L number suggests. The nmol/L measurement is preferred precisely because it bypasses this isoform confound.

Cardiovascular Conditions Linked to High Lp(a)

Heart attack (myocardial infarction)

Lp(a) is both atherogenic (drives plaque) and thrombogenic (promotes clotting)

A 3-4x higher lifetime risk in those with Lp(a) above 200 nmol/L versus below 75 nmol/L

Ischaemic stroke

Lp(a) promotes clot formation in cerebral arteries

Risk roughly doubles at very high Lp(a) levels

Aortic valve stenosis

Lp(a) promotes calcification of the aortic valve leaflets

This association is specific to Lp(a) and is not shared by LDL-C alone - a key reason to measure Lp(a) independently

Peripheral arterial disease

Plaque in leg arteries; shares same atherogenic mechanism

Elevated Lp(a) is an independent risk factor even after adjusting for LDL-C and other standard risk factors

Recurrent events after statin therapy

Statins barely affect Lp(a) - residual risk persists even when LDL-C is well controlled

If you have had a cardiac event on a statin, measuring Lp(a) explains some of the residual risk

The aortic stenosis link is unique to Lp(a): Most cardiovascular risk factors (LDL-C, blood pressure, smoking) are not strongly associated with aortic valve calcification. Lp(a) is one of the few blood markers specifically linked to progressive aortic valve disease. If you have been told you have a mildly thickened or calcified aortic valve, asking your GP to check Lp(a) is very reasonable.

Red Flags — When to Discuss Lp(a) with a Specialist

Lp(a) above 200 nmol/L (or 1 g/L)

This level is associated with very significantly elevated cardiovascular risk - roughly equivalent to adding one risk tier to your overall risk score. Warrants referral to a lipid specialist or preventive cardiologist.

High Lp(a) plus premature family history

A first-degree relative with heart attack or stroke before age 55 (men) or 65 (women) combined with elevated Lp(a) strongly points to familial risk. This combination justifies early and aggressive risk reduction.

Cardiac event on a statin with normal LDL-C

If you have had a heart attack or significant angina despite well-controlled LDL-C, elevated Lp(a) is one of the most common explanations for residual risk. Testing is essential in this scenario.

Aortic stenosis without conventional risk factors

Progressive narrowing of the aortic valve in someone who does not smoke and has normal cholesterol should prompt Lp(a) measurement - it is one of the main drivers of calcific aortic stenosis independent of LDL.

Very high Lp(a) plus elevated ApoB

The combination is multiplicative for risk. High Lp(a) contributes directly to the ApoB count (each Lp(a) particle carries one ApoB). When both are elevated, the total atherogenic particle burden is very high.

What to Do If Your Lp(a) Is High

Because Lp(a) cannot be easily lowered, the strategy focuses on reducing your total cardiovascular risk through every modifiable lever available.

Get tested - once is usually enough

Request an Lp(a) measurement (private, ~$30-$50) from your GP alongside your standard lipid panel. Use the same blood draw. Because Lp(a) is genetically fixed, a single adult measurement is usually sufficient for lifetime risk planning.

Record which unit was used

Note whether your result is in nmol/L or g/L or mg/dL. The cut-offs differ significantly. The nmol/L result is the most meaningful for cardiovascular risk assessment. Ask your GP to specify the unit on the request form if possible.

Assess your overall cardiovascular risk

Elevated Lp(a) is one piece of a larger risk picture. Your GP will use the Australian cardiovascular risk calculator (incorporating age, sex, blood pressure, smoking, diabetes, and LDL-C) to place your Lp(a) in context. High Lp(a) shifts the overall risk upward.

Aggressively lower every modifiable risk factor

Since Lp(a) itself is mostly non-modifiable, the therapeutic focus shifts to what you CAN change: LDL-C (or ApoB), blood pressure, blood glucose, smoking, weight, and physical activity. Getting LDL-C below 1.8 mmol/L (or ApoB below 0.65 g/L) on a statin plus ezetimibe is the standard target for high-Lp(a) individuals at elevated cardiovascular risk.

Organise cascade family screening

Because Lp(a) is inherited, first-degree relatives (parents, siblings, children) have approximately a 50% chance of carrying the same elevated level. Inform them and recommend they discuss testing with their own GP. This is the single most impactful action you can take for your family.

Ask about emerging therapies if very high

If your Lp(a) is above 200-300 nmol/L and you have cardiovascular disease or very high risk, ask your GP or cardiologist about clinical trials for Lp(a)-specific agents. Pelacarsen (an RNA-based therapy) and olpasiran are in phase 3 trials with 80-90% Lp(a) reduction. These are not yet approved in Australia as of 2025, but trial access may be available at major cardiac centres.

Upload results and track your full cardiovascular panel

Upload your pathology PDFs to SmarterBlood to see Lp(a) alongside ApoB, LDL-C, HDL, and triglycerides in one place. Tracking how your other modifiable markers respond to treatment over time is how you reduce your total cardiovascular burden, even when Lp(a) itself does not budge.

Family Screening — Who Else Should Be Tested?

The LPA gene variants that drive elevated Lp(a) follow an autosomal co-dominant inheritance pattern. In practical terms, each of your first-degree relatives — parents, brothers and sisters, and your own children once they reach adulthood — has a roughly 50% chance of carrying the same elevated Lp(a) level as you.

Cascade screening (systematically testing family members when one person is found to have elevated Lp(a)) is recommended by the European Society of Cardiology and is increasingly adopted in Australian preventive cardiology guidelines. It is one of the most cost-effective cardiovascular prevention strategies available, because it identifies high-risk individuals decades before a cardiac event.

What to tell your relatives: "I had a blood test that showed my Lp(a) (lipoprotein-a) is elevated. This is a genetic heart-risk marker. There is a 50% chance yours is also elevated. I would encourage you to ask your GP for a Lp(a) measurement the next time you have a blood test. It costs about $40 and only needs to be done once."

Getting Tested in Australia

Lp(a) is available at all major Australian pathology providers. It is a private-pay test (not Medicare-bulk-billed) costing approximately $30-$50. The test uses the same fasting blood draw as a standard lipid panel, though Lp(a) itself does not require fasting. Australian guidelines recommend that every adult have Lp(a) measured at least once.

If you want your ApoB measured at the same time (strongly recommended for a complete picture of your atherogenic particle burden), ask your GP to add both to the same pathology request. Upload your results to SmarterBlood and the AI will explain every marker in plain English, flag any discordance between Lp(a), ApoB, and LDL-C, and track how your cardiovascular panel changes over time.

Lipoprotein(a) / Lp(a) - Frequently Asked Questions

What is Lp(a) and why does it matter?

Lipoprotein(a), written Lp(a) and pronounced "L-P-little-a", is a lipoprotein particle similar to LDL but with an extra protein tail called apolipoprotein(a) attached. It is produced by the liver and its level is almost entirely determined by genetics - about 90% of the variation between people is inherited. Elevated Lp(a) independently raises the risk of heart attack, stroke, and aortic valve stenosis, even when LDL cholesterol is well controlled. It affects roughly 1 in 5 people worldwide.

What are the normal Lp(a) levels in Australia?

Australian labs may report Lp(a) in two different units. In mass units (g/L or mg/dL): elevated is above 0.5 g/L (50 mg/dL). In molar units (nmol/L): elevated is above 100-125 nmol/L, with some cardiologists using 75 nmol/L as a more conservative cut-off. The molar nmol/L measurement is now preferred internationally because it more accurately reflects particle number. Always check which units your lab used before comparing results.

Does Lp(a) change with diet or exercise?

Unlike LDL cholesterol, Lp(a) is largely unresponsive to diet and lifestyle changes. Most studies show that exercise, dietary fat changes, statins, and weight loss have minimal effect on Lp(a) levels. Niacin (nicotinic acid) can lower Lp(a) by 20-30% but is rarely used in Australia due to side effects. PCSK9 inhibitors (evolocumab, alirocumab) reduce Lp(a) by about 20-30%. Emerging targeted therapies (pelacarsen, olpasiran) in clinical trials can reduce Lp(a) by 80-90% but are not yet approved in Australia.

Do I need to test Lp(a) more than once?

Generally, Lp(a) needs to be measured only once in adulthood. Because it is genetically determined, it stays essentially constant throughout your life (barring major hormonal changes like menopause or significant kidney or liver disease). The European Society of Cardiology and the Australian national guidelines recommend measuring Lp(a) at least once in every adult. If your result is elevated, your first-degree relatives should also be tested (cascade screening).

What should I do if my Lp(a) is high?

If your Lp(a) is elevated, the main strategy is to aggressively lower everything else modifiable: get LDL-C (or ApoB) to target with statins and ezetimibe if needed, control blood pressure, quit smoking, manage blood sugar if diabetic, and maintain a healthy weight. These steps reduce the overall cardiovascular burden even though they do not lower Lp(a) directly. Tell first-degree relatives they should also be tested. Ask your GP about referral to a cardiologist or lipid clinic if your Lp(a) is very high (above 200 nmol/L or 1 g/L) or if you have family members with premature heart disease.

Is the Lp(a) test covered by Medicare in Australia?

Lp(a) testing is not on the standard Medicare lipid panel (MBS item 66500). It is typically a private-pay test costing approximately $30-$50 at major Australian pathology labs. Some specialist lipid clinic appointments or cardiovascular risk assessments include it as part of a comprehensive panel. A GP can add it to a pathology request and it uses the same blood sample as a standard lipid panel.

Which ethnic groups have the highest Lp(a) levels?

Lp(a) levels vary significantly by ethnicity. People of African descent have the highest average Lp(a) levels (often 2-3 times higher than European populations). South Asian (Indian subcontinent) populations also tend to have higher Lp(a). European and East Asian populations have lower average levels. This means ethnicity-specific risk thresholds are sometimes applied. If you are of African or South Asian descent, even a result in the "normal" range for European populations may represent elevated risk relative to your ancestry.