Lipoprotein(a) Risk Interpreter
Lipoprotein(a) Risk Interpreter
Read an Lp(a) result in the unit it was reported in — mg/dL or nmol/L — against the thresholds published in that unit. The two units measure different things and do not convert with a fixed factor, and the guidelines themselves pair 50 mg/dL with both 105 and 125 nmol/L. This page shows where they agree and where they do not.
Is this Lp(a) high?
Lp(a) + unit → risk bandLp(a) reported as 160 nmol/L.
Thresholds in the unit they were published in
mg/dL: below 30 rule-out · 30 to 50 grey zone · above 50 rule-in (EAS 2022, ESC/EAS 2025) · 50 or above high (ACC/AHA 2026) · above 150 very high (EAS/EFLM 2016) · above 180 extreme (ESC/EAS 2019)
- nmol/L
- particle number: one apolipoprotein(a) per particle, whatever its size. The unit consensus statements recommend
- mg/dL
- the mass of the whole particle, which depends on how many kringle IV type 2 repeats the patient’s apolipoprotein(a) carries
- 2 to 2.5
- the approximate nmol/L per mg/dL the EAS 2022 FAQ gives — explicitly as an approximation. The guidelines use 2.1, 2.4 and 2.5 in different places
Worked example
Lp(a) reported as 160 nmol/L.
The report is in nmol/L, so the nmol/L thresholds are used — no conversion
160 is not above 430 and not 250 or above
160 is above 125 nmol/L → above the EAS 2022 rule-in threshold, the ACC/AHA 2026 high threshold and the ESC/EAS 2025 threshold of 105
Had the same patient been measured in mg/dL, the result would have been somewhere around 64 to 80 mg/dL depending on isoform — raised either way, but not a number to write down as if it were measured
The same 50 mg/dL, three nmol/L pairings
| Document | Mass threshold | Paired particle threshold | Implied factor |
|---|---|---|---|
| EAS consensus 2022 | above 50 mg/dL | above 125 nmol/L | 2.5 |
| ESC/EAS focused update 2025 | above 50 mg/dL | above 105 nmol/L | 2.1 |
| ACC/AHA 2026 | 50 mg/dL or above | 125 nmol/L or above | 2.5 |
| ESC/EAS 2019 (extreme level) | above 180 mg/dL | above 430 nmol/L | 2.4 |
| EAS/EFLM 2016 (flag) | 50 mg/dL or above, about the 80th percentile | No nmol/L figure given | — |
What the documents agree on
| Question | Answer | Source |
|---|---|---|
| Who should be tested? | Every adult, at least once in a lifetime | EAS 2022; ESC/EAS 2019 and 2025; ACC/AHA 2026 |
| Should it be repeated? | Usually not — it is genetically determined and stable | EAS 2022; ACC/AHA 2026 |
| Which unit? | nmol/L, with an isoform-insensitive assay | EAS 2022 |
| Is there a threshold effect? | No — risk rises continuously | EAS 2022 |
Two units that measure different things
Lipoprotein(a) is an LDL-like particle with an extra protein, apolipoprotein(a), attached. Apolipoprotein(a) contains a variable number of repeated kringle IV type 2 domains, inherited and different from person to person, so the particles themselves differ in size and mass. A result in nmol/L counts particles. A result in mg/dL weighs them. Two people with the same number of particles can have very different mass concentrations, which means there is no fixed factor between the units: the right factor for any individual depends on their own isoform.
A single factor is used anyway, and the guidelines illustrate the problem better than any example could. The 2022 European Atherosclerosis Society consensus pairs 50 mg/dL with 125 nmol/L. The 2025 ESC/EAS focused update pairs the same 50 mg/dL with 105 nmol/L. The 2019 ESC/EAS guideline pairs 180 mg/dL with 430 nmol/L. Those are factors of 2.5, 2.1 and 2.4 for one analyte. The EAS’s own frequently-asked-questions paper says a factor of 2 to 2.5 gives only an approximate value. So this page does not convert: it reads an nmol/L result against thresholds stated in nmol/L, and a mg/dL result against thresholds stated in mg/dL.
In mg/dL the current documents agree: below 30 is low, 30 to 50 is a grey zone, and above 50 is raised. In nmol/L they agree below 75 and above 125, and disagree between 105 and 125, where the 2025 ESC/EAS threshold says significant and the EAS 2022 consensus says grey zone. That band has its own result on this page rather than being quietly assigned to one side. At the top of the range the 2026 ACC/AHA guideline associates 250 nmol/L with at least a two-fold risk, and the 2019 ESC/EAS guideline associates levels above 430 nmol/L with a lifetime risk comparable to heterozygous familial hypercholesterolaemia.
What to do with a raised value is less contested. Measure Lp(a) at least once in every adult. Treat a raised level as a risk enhancer: it tips borderline decisions towards treatment and argues for a lower LDL-C within the patient’s category, which the LDL target by risk category interpreter sets. Manage every modifiable risk factor. Offer testing to first-degree relatives. For converting an old result, the lipoprotein(a) unit converter shows how far the answer moves across the factors in use.
Frequently asked questions
What Lp(a) level is considered high?
Above 50 mg/dL in every current European and American document. In nmol/L, above 125 is raised on the EAS 2022 consensus and the 2026 ACC/AHA guideline, while the 2025 ESC/EAS focused update uses above 105 nmol/L. Below 30 mg/dL or 75 nmol/L is considered low.
Can I convert Lp(a) from mg/dL to nmol/L?
Only approximately, because particle mass varies with the apolipoprotein(a) isoform. The EAS says multiplying mg/dL by 2 to 2.5 gives an approximate nmol/L value, and the guidelines themselves use factors of 2.1, 2.4 and 2.5. Read a result against thresholds in the unit it was measured in.
How often should Lp(a) be measured?
At least once in every adult’s lifetime, according to the EAS 2022 consensus, the ESC/EAS guideline and the 2026 ACC/AHA guideline. It is largely genetically determined and stable, so repeat testing is usually unnecessary unless the first sample was taken during illness, pregnancy or kidney disease.
Do statins lower Lp(a)?
No, and they may raise it slightly. That is not a reason to avoid them: a raised Lp(a) makes lowering LDL cholesterol more important, not less.
Related calculators
References
- 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.
- Kronenberg F, Mora S, Stroes ESG, et al. Frequent questions and responses on the 2022 lipoprotein(a) consensus statement of the European Atherosclerosis Society. Atherosclerosis. 2023;374:107–120.
- Mach F, et al. 2025 Focused Update of the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J. 2025;46(42):4359–4378. doi:10.1093/eurheartj/ehaf190.
- Guasti L, Gaudio GV, Lupi A. What is new in the 2025 Focused Update of the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. ESC CardioPractice, European Society of Cardiology, 2 December 2025.
- Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Eur Heart J. 2020;41(1):111–188.
- Blumenthal RS, Morris PB, Gaudino M, et al. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia. J Am Coll Cardiol. Published online 13 March 2026. doi:10.1016/j.jacc.2025.11.016. Also in Circulation, doi:10.1161/CIR.0000000000001423.
- Nordestgaard BG, Langsted A, Mora S, et al. Fasting is not routinely required for determination of a lipid profile: clinical and laboratory implications including flagging at desirable concentration cut-points — a joint consensus statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine. Eur Heart J. 2016;37(25):1944–1958.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.