Lipoprotein(a) test: who needs one and how to read it
Lipoprotein(a), or Lp(a), is a cholesterol-carrying particle in the blood. A high level may mean a higher risk of heart and blood vessel disease, even if your other cholesterol numbers are healthy. It is not usually part of a routine cholesterol panel, and the genes you get from your parents decide how much you have. (NHLBI, 2024) Your doctor decides what your result means for you.
Who should get tested
| Source | What it says |
|---|---|
| National Lipid Association, 2024 | Measure at least once in every adult. (NLA, 2024) |
| European Atherosclerosis Society, 2022 | Measure at least once in adults, and read it alongside your overall heart risk. (EAS, 2022) |
| American Heart Association, 2022 | Evidence for screening is strongest in people with a family or personal history of heart or artery disease. (AHA, 2022) |
| ACC/AHA cholesterol guideline, 2018 | A family history of early heart disease is a reason to consider measuring it. (ACC/AHA, 2018) |
| NIH (NHLBI and MedlinePlus) | A provider may order it for a family history of stroke or early heart disease, or if you do not know your family history. (NHLBI, 2024) MedlinePlus lists an Lp(a) test "once as an adult." (MedlinePlus, 2026) |
| USPSTF | Its 2022 statin recommendation for adults 40 to 75, which sets how heart risk is estimated, does not include Lp(a). (USPSTF, 2022) |
Where they differ: the National Lipid Association and the European Atherosclerosis Society favor testing every adult once, while the AHA statement and the 2018 ACC/AHA guideline point mainly to people with a family or personal history. (NLA, 2024) (EAS, 2022) (AHA, 2022) (ACC/AHA, 2018) The National Lipid Association estimates that about 1 in 5 people have a raised level, yet few are tested. (NLA, 2024)
Reading the result: mg/dL or nmol/L
Labs report Lp(a) in one of two units: milligrams per deciliter (mg/dL), a weight, or nanomoles per liter (nmol/L), a particle count. The AHA says there is no unbiased conversion factor between the two, and the European Atherosclerosis Society does not recommend using a standard factor because tests vary a lot. (AHA, 2022) (EAS, 2022) So compare your number only with the cut-off in the same unit. The pairs below are separate cut-offs set by each group, not conversions.
| Result | National Lipid Association, 2024 | European Atherosclerosis Society, 2022 | ACC/AHA, 2018 |
|---|---|---|---|
| Under 30 mg/dL or under 75 nmol/L | Low risk | Rules out added risk | No separate band |
| 30 to 50 mg/dL or 75 to 125 nmol/L | Intermediate risk | Grey zone | No separate band |
| 50 mg/dL or more, or 125 nmol/L or more | High risk | Rules in added risk | Risk-enhancing factor, more so at higher levels |
Sources for the table: (NLA, 2024) (EAS, 2022) (ACC/AHA, 2018) The European statement writes the rule-in mark as over 50 mg/dL or over 125 nmol/L in one place and 50 or more in another. (EAS, 2022)
A high Lp(a) is one risk factor, not a diagnosis. The European Atherosclerosis Society describes a causal link, rising steadily with the level, between Lp(a) and heart and blood vessel disease, including narrowing of the aortic valve, and says to read the result alongside your overall heart risk. (EAS, 2022) Your doctor puts it together with your other numbers; see cholesterol test results for the rest of the panel.
Why one test is usually enough
- More than 90% of your Lp(a) level is set by your genes. Adult levels are usually reached by about age 5, though they may rise until adulthood. (EAS, 2022)
- The NIH heart institute says your level is unlikely to change much from childhood to old age. (NHLBI, 2024)
- Where they differ: the AHA notes that a person's level can vary by up to 20% between tests, so for some people an average of 2 tests taken at different times may help. (AHA, 2022) The European statement notes that levels tend to rise in women at menopause, about double in pregnancy, and can be higher with kidney disease. (EAS, 2022) Ask your doctor whether a repeat makes sense for you.
Levels differ by ancestry
Black people of African descent and South Asian people have higher typical Lp(a) levels than White or East Asian people. (AHA, 2022) In the UK Biobank, median levels were 16 nmol/L in Chinese, 19 in White, 31 in South Asian and 75 in Black participants. (EAS, 2022) The European statement also reports that the link between Lp(a) and heart disease holds across different ethnic groups. (EAS, 2022)
Testing your family
Because the level is inherited, a high result in one person can point to others. The National Lipid Association supports testing first-degree relatives (parents, brothers, sisters and children) of people with a high level. (NLA, 2024) The European statement says it seems reasonable to measure Lp(a) if a parent or sibling has a markedly high level, and the AHA says to consider family testing in the right people. (EAS, 2022) (AHA, 2022)
Questions people ask
Who should get a lipoprotein(a) test?
It depends on the group. The National Lipid Association (2024) and the European Atherosclerosis Society (2022) say every adult should have it measured at least once. The AHA (2022) says the case is strongest for people with a family or personal history of heart disease, and the NIH heart institute lists a family history of stroke or early heart disease, or not knowing your family history. (NLA, 2024) (EAS, 2022) (AHA, 2022) (NHLBI, 2024)
Do I need to repeat a lipoprotein(a) test?
Usually not. More than 90% of the level is set by your genes, and the NIH heart institute says it is unlikely to change much from childhood to old age. The AHA notes it can vary up to 20% within a person, so for some people an average of 2 tests may help. Levels tend to rise in women at menopause. (EAS, 2022) (NHLBI, 2024) (AHA, 2022)
Can I convert Lp(a) from mg/dL to nmol/L?
Not exactly. The AHA says there is no unbiased conversion factor, and the European Atherosclerosis Society advises against using a standard factor because tests vary. Compare your result with the cut-off given in the same unit as your report. (AHA, 2022) (EAS, 2022)
What is a high lipoprotein(a) level?
Groups use 50 mg/dL or 125 nmol/L as the high mark. The ACC/AHA guideline counts that as a factor that raises heart risk, and the National Lipid Association calls it high risk. Under 30 mg/dL or 75 nmol/L is low, and in between is a grey zone. (ACC/AHA, 2018) (NLA, 2024) (EAS, 2022)
Should my family get tested if my Lp(a) is high?
The National Lipid Association and the European Atherosclerosis Society support testing close relatives such as parents, brothers, sisters and children (cascade testing), and the AHA says to consider it. Talk to your doctor. (NLA, 2024) (EAS, 2022) (AHA, 2022)