Lipoprotein(a): the inherited heart risk most people never test
Lipoprotein(a), or Lp(a), is an LDL-like cholesterol particle carrying an extra protein called apolipoprotein(a). Your level is roughly 90 percent set by your genes, stays nearly constant for life, and independently raises your risk of heart attack, stroke and aortic valve stenosis. Around 1 in 5 people carry a raised level, yet almost nobody is tested. You only need the test once, statins do not lower it, and the first targeted drugs are still in outcome trials.
Key facts
- Lp(a) is an LDL particle with apolipoprotein(a) bolted on. Blood levels are roughly 70 to 90 percent genetically determined and largely fixed from childhood.12
- Genetic (Mendelian randomisation) studies show high Lp(a) is a causal driver of coronary disease, ischaemic stroke and calcific aortic stenosis, not just a bystander.34
- About 20 percent of people, roughly 1 in 5, have a level high enough to add meaningful risk.5
- Because the level barely changes, it is usually measured once in a lifetime, ideally reported in nmol/L.6
- Statins do not lower Lp(a) and may nudge it up slightly; it still matters, so the job is to drive every other risk factor down hard.7
On this page
What Lp(a) actually is
Picture an ordinary LDL particle, the kind a standard cholesterol test counts. Lp(a) is that particle with one extra component attached: a large, looping protein called apolipoprotein(a), or apo(a), linked to the LDL particle's apolipoprotein B. So every Lp(a) particle carries the atherogenic cargo of LDL plus this distinctive apo(a) tail.1
That tail is what makes Lp(a) more dangerous than its cholesterol content alone would suggest. Apo(a) structurally resembles plasminogen, a protein that dissolves blood clots, which is thought to let Lp(a) interfere with clot breakdown. The particle also ferries oxidised phospholipids, which are pro-inflammatory and appear to drive both artery furring and the calcification of heart valves. In short, Lp(a) combines the cholesterol-depositing behaviour of LDL with extra clot-promoting and inflammatory effects.14
This is why Lp(a) sits awkwardly on a normal lipid panel. It contributes to your measured LDL cholesterol but is not separated out, so two people with identical LDL-C can carry very different Lp(a). If you want the fuller picture of how particle count, not just cholesterol content, drives risk, our companion guide to ApoB and the lipid panel covers the surrounding map.
Why your level is fixed for life
Lp(a) is unusual among cardiovascular risk markers because it is almost entirely inherited. Blood concentration is controlled chiefly by a single gene, LPA, which codes for apo(a). Twin and family studies put heritability at roughly 70 to more than 90 percent, far higher than for LDL cholesterol, blood pressure or triglycerides.2
The genetics hinge on a quirk of the LPA gene: it contains a variable number of repeated segments called kringle IV type 2 repeats. More repeats broadly mean larger, slower-made apo(a) and lower Lp(a); fewer repeats mean smaller apo(a) and higher levels. Because you inherit one copy of LPA from each parent, your level is essentially decided at conception and reaches its adult set point in early childhood.2
The practical consequences follow directly. Your Lp(a) does not meaningfully respond to diet, weight loss, exercise or stopping smoking, all of which help your other lipids. It does not drift much with age (a modest rise can occur, and levels can climb after the menopause or with kidney disease). And because it is genetic, a high level in you flags possible high levels in your parents, siblings and children.
Evidence strength: that Lp(a) is largely genetically fixed is established from twin studies, family studies and genome-wide data, and is not controversial. The headline figure of roughly 80 to 90 percent heritability is consistent across European and African ancestry populations, though absolute levels differ substantially between ethnic groups, being higher on average in people of South Asian and African descent.2
The evidence that high Lp(a) causes harm
For a marker to be worth acting on, it helps to know it actually causes disease rather than merely accompanying it. Lp(a) clears a high bar here, because two independent lines of evidence point the same way.
First, large observational pooling. The Emerging Risk Factors Collaboration combined 36 prospective studies and over 126,000 people, finding that higher Lp(a) tracked higher rates of coronary heart disease and ischaemic stroke, broadly independent of conventional risk factors.8 Observational data alone, though, can be confounded.
Second, and more persuasively, Mendelian randomisation. Because LPA gene variants are dealt out randomly at conception and fixed for life, comparing people who inherited Lp(a)-raising variants with those who did not works like a natural randomised trial, sidestepping most confounding and reverse causation. These genetic studies consistently show that variants raising Lp(a) also raise the risk of heart attack, and crucially of calcific aortic valve stenosis, the narrowing of the heart's main outflow valve.34 Lp(a) is in fact the strongest known genetic risk factor for aortic stenosis, a condition with no drug treatment, only valve replacement.
The 2022 European Atherosclerosis Society (EAS) consensus statement, led by Kronenberg and colleagues, drew these threads together and concluded that the relationship is causal and continuous: there is no clear safe threshold, with risk rising as levels climb.6 The same work suggests the absolute Lp(a) reduction needed for a clinically worthwhile fall in events is large, on the order of 50 to 100 mg/dL, which has shaped how the new drugs are being tested.6
Reading your number: thresholds and units
Two reporting units are in use, and they do not convert cleanly. Modern guidance favours nmol/L (a count of particles) over mg/dL (a measure of mass), because mass-based assays can be thrown off by the variable size of apo(a). There is no reliable fixed conversion factor between the two, so a result should ideally come with its unit clearly stated and an assay calibrated to the international (WHO/IFCC) reference standard.6
Thresholds differ slightly between bodies, partly reflecting that grey zone of uncertainty near the cut-points. The table below sets out commonly used bands. Treat them as a guide to the strength of concern, not as hard on/off switches.
| Level (nmol/L) | Approx. (mg/dL) | Interpretation |
|---|---|---|
| Below 75 | Below ~30 | EAS: Lp(a)-attributable risk largely ruled out. |
| 75 to 125 | ~30 to 50 | Grey zone; weigh alongside other risk factors. |
| Above 90 (HEART UK) | ~38+ | HEART UK: minor-to-moderate added risk; manage other factors. |
| Above 125 (EAS) | Above ~50 | EAS: Lp(a)-attributable risk ruled in. |
| 200 to 400 (HEART UK) | ~80 to 160 | High risk; intensive risk-factor control. |
| Above 400 (HEART UK) | Above ~160 | Very high risk; consider specialist lipid review. |
HEART UK also flags that a first-degree relative with a level above 200 nmol/L is a reason to test yourself, given the inherited pattern.9 If your result lands in or near the grey zone, it is the rest of your risk picture, blood pressure, ApoB, smoking, diabetes, family history, that decides how aggressively to act.
Why statins do not lower it (and it still matters)
This is the counter-intuitive part. Statins, the mainstay of cholesterol treatment, are excellent at lowering LDL cholesterol but do not lower Lp(a). If anything they raise it modestly. A 2020 patient-level meta-analysis of six statin trials by Tsimikas and colleagues, pooling more than 5,000 people, found statins produced a small but statistically significant increase in Lp(a) of roughly 8 to 24 percent depending on the statin.7
It is important not to misread this. The rise is small, and it is not a reason to avoid statins, whose net benefit on LDL and cardiovascular events is overwhelming and well proven. But it does mean a statin will not fix a high Lp(a), and your Lp(a)-related risk persists on top of whatever your statin achieves for LDL. That residual risk is precisely why knowing your Lp(a) changes the plan even when no drug targets it directly.
A raised Lp(a) is not a reason to stop or refuse a statin. Statins lower LDL and ApoB, which is exactly what you want when Lp(a) is high. The point is the opposite: high Lp(a) usually argues for treating LDL and other risk factors more intensively, not less. Any change to prescribed medication should be discussed with your GP or lipid clinic, not made on the basis of a single private test result.
What you can actually do today
There is no licensed therapy that selectively lowers Lp(a) and is proven to cut events, so current management is about controlling everything else hard. A high Lp(a) effectively raises your global risk, which lowers the threshold at which intervention on modifiable factors makes sense. In practice that means:
- Lower LDL cholesterol and ApoB aggressively. This is the single most actionable lever. Statins, and where needed ezetimibe or PCSK9 inhibitors, reduce the LDL and ApoB particle burden that compounds Lp(a) risk. PCSK9 inhibitors also lower Lp(a) by around 20 to 30 percent as a side effect, though they are not licensed for that purpose.6
- Treat blood pressure, blood sugar and smoking. Standard cardiovascular hygiene matters more, not less, when an unmodifiable factor is stacked on top.
- Inform your family. Because Lp(a) is inherited, a high result is a prompt to mention testing to first-degree relatives.
- Do not chase it with supplements or diet. No lifestyle measure reliably lowers Lp(a). Niacin lowers it modestly but failed to improve outcomes and is not recommended for this.6
To organise statins, ezetimibe and any add-ons coherently rather than piecemeal, our stack builder can help you map what you are taking and why, and our wider insights cover the surrounding metabolic picture.
The targeted drugs in trials (be honest: not proven yet)
For decades Lp(a) was untreatable. That is now changing, but the honest position in 2026 is that the new agents are not yet proven to reduce heart attacks or strokes in completed outcome trials. Two are furthest along, both designed to switch off apo(a) production in the liver:
- Pelacarsen is an antisense oligonucleotide given by monthly injection. Phase 2 data showed it lowers Lp(a) by around 80 percent. Its outcome trial, Lp(a)HORIZON, has enrolled over 8,000 people with established cardiovascular disease and high Lp(a); topline results are expected in 2026.10
- Olpasiran is a small interfering RNA (siRNA) given by injection every 12 weeks or so. Its phase 2 OCEAN(a)-DOSE trial showed sustained reductions of more than 90 percent. Its outcome trial is running, with results anticipated around 2027.11
The critical caveat is the gap between surrogate and outcome. These drugs dramatically lower the Lp(a) number, but whether that translates into fewer cardiovascular events, and at acceptable safety, is exactly what the ongoing trials are designed to answer. Mendelian randomisation gives good reason for optimism, yet history is littered with markers that moved without benefit. Until the outcome data report and a drug is licensed, Lp(a)-lowering therapy is not available in routine practice. For now, knowing your number guides how hard to treat the rest, and may make you eligible for a trial.
Getting tested in the UK
Lp(a) is not part of the standard NHS lipid panel and is not yet measured routinely. It is most readily justified on the NHS where there is premature cardiovascular disease, a strong family history, familial hypercholesterolaemia, or a first-degree relative with a very high level, usually via referral to a lipid clinic. HEART UK, the UK cholesterol charity, advocates wider testing and is a useful patient resource.9
Privately, Lp(a) is widely available without referral, often for around 30 to 70 pounds as a single test, and is increasingly bundled into advanced lipid panels. If you test privately, ask for a result in nmol/L from a standardised assay, and take it back to your GP rather than acting alone. The key efficiency: because the level is fixed, you genuinely only need this test once.
- Given my family history of early heart disease or stroke, would a one-off Lp(a) test be reasonable, ideally reported in nmol/L?
- If my Lp(a) is raised, should we be treating my LDL cholesterol and ApoB more intensively than my QRISK3 score alone suggests?
- Does my result meet the threshold for a lipid-clinic referral (for example very high Lp(a), or a relative above 200 nmol/L)?
- Should my first-degree relatives be offered testing?
- Are there local trials of Lp(a)-lowering therapy I could be considered for?
References
- Reyes-Soffer G, Ginsberg HN, Berglund L, et al. Lipoprotein(a): A Genetically Determined, Causal, and Prevalent Risk Factor for Atherosclerotic Cardiovascular Disease. A Scientific Statement From the American Heart Association. Arterioscler Thromb Vasc Biol. 2022;42(1):e48-e60. ahajournals.org.
- Schmidt K, Noureen A, Kronenberg F, Utermann G. Structure, function, and genetics of lipoprotein(a). J Lipid Res. 2016;57(8):1339-1359. Genetics and pathophysiology review, JAHA 2024.
- Clarke R, Peden JF, Hopewell JC, et al. Genetic Variants Associated with Lp(a) Lipoprotein Level and Coronary Disease. N Engl J Med. 2009;361(26):2518-2528. nejm.org.
- Kamstrup PR, Tybjaerg-Hansen A, Nordestgaard BG. Elevated Lipoprotein(a) and Risk of Aortic Valve Stenosis in the General Population. J Am Coll Cardiol. 2014;63(5):470-477. jacc.org.
- Tsimikas S. A Test in Context: Lipoprotein(a): Diagnosis, Prognosis, Controversies, and Emerging Therapies. J Am Coll Cardiol. 2017;69(6):692-711. jacc.org.
- Kronenberg F, Mora S, Stroes ESG, et al. Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement. Eur Heart J. 2022;43(39):3925-3946. academic.oup.com.
- Tsimikas S, Gordts PLSM, Nora C, Yeang C, Witztum JL. Statin therapy increases lipoprotein(a) levels. Eur Heart J. 2020;41(24):2275-2284. academic.oup.com.
- Erqou S, Kaptoge S, Perry PL, et al (Emerging Risk Factors Collaboration). Lipoprotein(a) Concentration and the Risk of Coronary Heart Disease, Stroke, and Nonvascular Mortality. JAMA. 2009;302(4):412-423. jamanetwork.com.
- Cegla J, Neely RDG, France M, et al. HEART UK consensus statement on Lipoprotein(a): A call to action. Atherosclerosis. 2019;291:62-70. atherosclerosis-journal.com.
- Tsimikas S, Karwatowska-Prokopczuk E, Gouni-Berthold I, et al. Lipoprotein(a) Reduction in Persons with Cardiovascular Disease (pelacarsen phase 2). N Engl J Med. 2020;382(3):244-255. nejm.org.
- O'Donoghue ML, Rosenson RS, Gencer B, et al. Small Interfering RNA to Reduce Lipoprotein(a) in Cardiovascular Disease (olpasiran, OCEAN(a)-DOSE). N Engl J Med. 2022;387(20):1855-1864. nejm.org.
This article is educational and does not constitute medical advice, diagnosis, or a treatment recommendation. Medication uses described as “off-label” are not licensed for that purpose in the UK and should only be considered under qualified clinical supervision. Always speak to your GP, pharmacist, or a registered specialist before starting, stopping, or changing any treatment. If you have severe or alarm symptoms - unintentional weight loss, blood in your stool, difficulty swallowing, persistent vomiting, a fever, or severe pain - seek urgent medical care.