Lipoprotein A: A Hereditary Risk Factor for Atherosclerosis

Serum lipoprotein(a) is a laboratory test that helps clarify the hereditary risk of atherosclerosis, myocardial infarction, ischemic stroke, peripheral arterial disease, and aortic valve stenosis. Today, it is no longer an "additional, rare test for select patients," but an essential component of modern cardiovascular risk stratification. [1]

Lipoprotein(a) is a particle similar to low-density lipoproteins, but with an additional protein, apolipoprotein(a). This characteristic makes it simultaneously atherogenic, pro-inflammatory, and prothrombotic, promoting both atherosclerotic plaque growth and disrupting fibrinolysis. [2]

A high lipoprotein(a) level does not necessarily cause symptoms. A person can feel well, have a "fair" standard lipid profile, and still carry a significantly elevated lifelong vascular risk. This is why this test is particularly valuable not for diagnosing a complaint "here and now," but for a more accurate assessment of future risk. [3]

Current professional guidelines increasingly recommend measuring lipoprotein(a) at least once in a lifetime for every adult. However, in routine practice, this test is not yet universally included in standard screening, leading to its importance often being underestimated. In other words, the role of this test has grown faster at the expert recommendation level than in routine clinical practice. [4]

For practical medicine, it's important not only to identify elevated lipoprotein(a) levels but also to properly explain the meaning of the result to the patient. This indicator doesn't mean a vascular accident is inevitable, but it does indicate that other risk factors—blood pressure, smoking, diabetes, obesity, chronic kidney disease, and high low-density lipoprotein cholesterol—should be taken especially seriously. [5]

Table 1. What does a lipoprotein test show?

Question	Short answer
What does the analysis measure?	Blood lipoprotein(a) concentration
What is this particle?	Low-density lipoprotein-like particle with apolipoprotein(a)
What does a high result show?	Increased hereditary risk of atherosclerotic vascular events and aortic valve stenosis
Can this test replace a regular lipid profile?	No, it complements, not replaces, the standard lipid profile.
Is this a genetically determined indicator?	Yes, more than 90%
Does testing help with normal "regular" cholesterol?	Yes, it can reveal underestimated risk

Table base: [6]

What is lipoprotein(a) and why is it important?

Lipoprotein(a) has long been underestimated because standard lipidology focused primarily on low-density lipoprotein cholesterol. It is now known to be an independent causal factor in cardiovascular risk that acts independently of many other indicators and can enhance their adverse effects. [7]

Molecularly, lipoprotein(a) consists of a lipoprotein-like particle with apolipoprotein B and apolipoprotein(a) attached to it. The structure of apolipoprotein(a) is variable: the number of repeating protein domains varies from person to person. This is why two patients with the same "mass" estimate in mg per deciliter may not have exactly the same number of particles and not completely comparable risk. [8]

The clinical significance of lipoprotein(a) extends beyond cholesterol transport. This particle is involved in the formation of atherosclerotic plaques, can bind to fibrin, and disrupt normal clot dissolution mechanisms. Therefore, high lipoprotein(a) levels are associated not only with coronary heart disease, but also with ischemic stroke, peripheral arterial disease, and aortic valve disease. [9]

It's especially important for patients to understand that diet and physical activity have little effect on lipoprotein(a) levels themselves. This doesn't mean lifestyle is useless. On the contrary, precisely because the indicator itself is difficult to modify, monitoring body weight, blood pressure, blood sugar, quitting smoking, and lowering LDL cholesterol become even more important. [10]

Another key detail is that the risk associated with high lipoprotein(a) is not the same for everyone. Its impact must be assessed in the context of the overall clinical picture. A person without other risk factors may have a lower absolute risk than a patient with normal lipoprotein(a) but diabetes, smoking, hypertension, and pre-existing atherosclerosis. However, all other things being equal, high lipoprotein(a) still worsens the prognosis. [11]

Table 2. How lipoprotein(a) differs from a normal lipid profile

Parameter	Normal lipid profile	Lipoprotein(a)
The main task	Evaluation of current lipid metabolism and treatment monitoring	Clarification of hereditary cardiovascular risk
Changes with diet and medications	Often yes	Usually not much
Genetic predisposition	Partial	Very high
Needed for primary prevention	Yes	Yes, as a clarifying risk test
Useful in familial early vascular pathology	Yes	Especially useful
May be elevated with "normal cholesterol"	Not always	Yes

Table base: [12]

Who is prescribed the test and when?

The most current approach is to recommend that every adult have at least one lipoprotein(a) measurement to assess cardiovascular risk. This is no longer just a test "as indicated in very seriously ill patients," but a way to detect inherited vulnerabilities early that would otherwise go undetected. [13]

This test is especially important for people with a family history of premature heart attacks, strokes, or other vascular events. If a father, brother, mother, or sister developed the disease earlier than expected, lipoprotein(a) is one of the first markers to be tested. This approach helps determine whether a family history conceals a hereditary link to high lipoprotein(a). [14]

The test is also particularly useful in patients with existing atherosclerotic disease if normal lipids do not explain the severity of the situation. A typical example is myocardial infarction or recurrent vascular events with not very high low-density lipoprotein cholesterol. In such a situation, high lipoprotein(a) may explain part of the "residual risk." [15]

Another important group is patients with or suspected of having familial hypercholesterolemia. High lipoprotein(a) is often more common in these individuals than in the general population and may further increase the risk. Furthermore, with very high lipoprotein(a), measured low-density lipoprotein cholesterol may appear higher than expected, sometimes complicating the interpretation of the clinical picture. [16]

In children, the test is not universal screening, but it is warranted in high-risk groups. Selective testing is recommended for children with familial hypercholesterolemia, early vascular events in first-degree relatives, relatives with elevated lipoprotein(a), and children with ischemic stroke of unknown cause. The detection of a high level in a child should prompt a cascade family screening. [17]

Table 3. Main indications for lipoprotein analysis

Situation	Is analysis necessary?
Every adult at least once in their life	Yes, it is desirable.
Family history of early heart attack or stroke	Yes
Already confirmed atherosclerotic vascular disease	Yes
Suspected familial hypercholesterolemia	Yes
Recurrent vascular events with not very high normal cholesterol	Yes
A child from a high-risk group	Yes, selectively
A completely healthy child without risk factors	There is usually no routine need

Table base: [18]

How to take the test and how often to repeat it

In practice, the test is performed on venous blood. Special preparation is usually not required, but laboratory guidelines vary. Some labs allow for a relaxed sample, while others require a 9- to 12-hour fast, especially if lipoprotein(a) is ordered simultaneously with an extended lipid profile and triglycerides. Therefore, it is important to follow the specific laboratory's instructions. [19]

Current data indicate that lipid tests, including lipoprotein(a), can be performed in a non-fasting state in many situations. However, if the patient has severe hypertriglyceridemia, if other parameters requiring fasting are being assessed concurrently, or if the laboratory has its own internal preparation guidelines, it is preferable to follow the local protocol. [20]

Before testing, it is important to inform your doctor and the laboratory about any medications and supplements you are taking. For lipoprotein(a), this is not as critical as for some hormonal or vitamin tests, but certain substances and clinical conditions may affect the interpretation of the results. Patients should not stop taking medications just for the sake of a single test without consulting their doctor. [21]

A unique feature of lipoprotein(a) is that its levels remain relatively stable throughout life for most people. This is why a single test is often sufficient. Exceptions are possible if the initial result falls in the intermediate zone, if the test was performed before menopause and then several years passed, or if conditions that can alter the level, such as proteinuria, chronic kidney disease, or hypothyroidism, develop later. [22]

A genetic test to assess lipoprotein(a) is generally not necessary. For clinical practice, direct measurement of blood concentration is sufficient. This is much simpler, less expensive, and more practical than attempting to predict risk through genetic variants, especially since the laboratory test itself already reflects the final biological effect of hereditary traits. [23]

Table 4. Preparation for analysis and re-examination

Question	Practical answer
Is fasting necessary?	Depends on the laboratory, often 9 to 12 hours is desirable, especially when lipid profiling is done at the same time
Can I take the test without fasting?	In many cases, yes, unless there are special conditions.
Should I stop taking the medication?	No, not on my own.
Is a genetic test necessary?	Usually no
How often should the analysis be repeated?	Usually once in a lifetime is enough
When might a repeat be necessary?	Intermediate outcome, menopause, chronic kidney disease, hypothyroidism, changes in clinical status

Table base: [24]

How to interpret the result

The most important concept when interpreting lipoprotein(a) is that risk is continuous. This means there is no absolute magical threshold below which risk is zero and above which it suddenly becomes high. However, practical guidelines are needed, and current guidelines suggest the use of low, intermediate, and high-risk zones. [25]

According to the National Lipid Association's 2024 update, values below 75 nmol/L are considered low risk, values between 75 and 125 nmol/L are considered intermediate, and values of 125 nmol/L and above are considered high risk. If a lab reports results in mg/dL, the guidelines are closer to the low zone (below 30), intermediate (30 to 50), and high (50 and above), but these numbers cannot be converted to a single, rigid factor for each individual. [26]

Many experts consider nmol per liter to be the preferred unit because it better reflects particle number. This is especially important due to the variability in apolipoprotein(a) size. If a laboratory uses mg per deciliter, the result is still clinically useful, but comparing such values between laboratories, and especially manually converting them to nmol per liter, requires extreme caution. [27]

Another fundamental point: lipoprotein(a) should not be interpreted in isolation from the overall clinical context. The same indicator has different practical significance in a young, non-smoking individual without diabetes or hypertension than in a patient with a history of myocardial infarction, chronic kidney disease, and high LDL cholesterol. In the former case, it's more about early warning, while in the latter, it's about explaining residual risk and the need for more intensive prevention. [28]

There are also biological situations where repeat measurements can be useful. The intermediate zone is particularly insidious: some people later shift into a higher risk category. This is more often observed after menopause, with proteinuria, chronic kidney disease, and hypothyroidism. Therefore, the "gray zone" cannot simply be ignored as "almost normal." [29]

Finally, it is important to remember that Lp(a)-carried cholesterol is included in the standard measurement of low-density lipoprotein cholesterol. Attempts to "manually subtract" the estimated proportion of Lp(a) from it based on a fixed formula are not recommended today, as this may lead to underestimation of the actual risk and insufficient treatment. [30]

Table 5. Practical interpretation of the result

Result	Practical assessment
Below 75 nmol per liter	Usually low risk associated specifically with lipoprotein(a)
75 to 125 nmol per liter	Intermediate zone, overall risk assessment required
125 nmol per liter and above	High risk, especially with other factors
Below 30 mg per deciliter	Approximately corresponds to the low risk zone
30 to 50 mg per deciliter	Intermediate zone
50 mg per deciliter and above	High risk zone
Any high level in the presence of existing atherosclerosis	Particularly clinically significant

Table base: [31]

What does elevated lipoprotein(a) mean and what to do next?

An elevated lipoprotein(a) level does not necessarily mean it must be "urgently reduced at any cost" with a specific drug. In routine practice today, the primary purpose of the result is to clarify risk and select a more active preventive strategy. In other words, a high level is a signal that gentle observation may no longer be sufficient. [32]

The first practical step after receiving a high result is to evaluate the patient's entire cardiovascular profile. It is important to determine whether the patient has hypertension, diabetes, obesity, smoking, chronic kidney disease, previous vascular events, high low-density lipoprotein cholesterol, familial hypercholesterolemia, or an adverse family history. The more associated factors, the higher the absolute risk. [33]

The second step is to take a serious approach to reducing low-density lipoprotein cholesterol. Current guidelines emphasize that until effective and widely available specific lipoprotein(a) medications become routine, aggressive control of low-density lipoprotein cholesterol and other modifiable factors remains the primary method of risk reduction. For very high-risk patients, expert reviews suggest a target of approximately 55 mg per deciliter for low-density lipoprotein cholesterol. [34]

The third step is a family-based approach. If lipoprotein(a) is high in one person, it often makes sense to test first-degree relatives: parents, siblings, and children. This is especially important for early heart attacks, strokes, and familial hypercholesterolemia. This cascade approach allows us to identify those who appear healthy but already have an inherently increased risk. [35]

The fourth step is not to overestimate the effectiveness of non-drug measures alone. Diet, physical activity, weight management, and smoking cessation are crucial for the overall prognosis, but they usually do not significantly reduce lipoprotein(a) levels. This should be explained frankly to the patient: the goal of lifestyle is not so much to "lower the test number" as to reduce the overall risk of vascular accident. [36]

Finally, high lipoprotein(a) in a patient with a history of heart attack, ischemic stroke, peripheral arterial disease, or severe aortic stenosis requires particularly careful monitoring. Here, the result ceases to be simply a prognostic marker and becomes part of the explanation for why risk remains high even with seemingly normal lipids. [37]

Table 6. What to do if you have elevated lipoprotein

Step	Practical significance
Confirm units of measurement and laboratory	To avoid misinterpretation
Assess overall cardiovascular risk	More important than one number of analysis
Reduce low-density lipoprotein cholesterol as actively as possible according to risk	The main current way to reduce risk
Look for familial hypercholesterolemia and an early family history	Helps to clarify hereditary risk
Examine first-line relatives	Allows you to find hidden cases
Control blood pressure, blood sugar, body weight, and smoking	Reduces overall vascular risk
In severe clinical situations, refer to a lipidologist or cardiologist	More in-depth tactics are needed

Table base: [38]

Treatment, modern possibilities and limitations

Statins remain first-line therapy in patients with high cardiovascular risk, even if lipoprotein(a) is elevated. They do not lower lipoprotein(a) itself and may even slightly increase it, but this should not be a reason to refuse treatment, because overall vascular risk is significantly and convincingly reduced with statins. [39]

Ezetimibe and bempedoic acid generally do not have a significant clinically significant effect on lipoprotein(a). However, they are useful as part of a strategy to lower LDL cholesterol, especially if statins alone fail to achieve the target level or if statins are poorly tolerated. Thus, their value in the setting of high LDL(a) is indirect, not direct. [40]

Proprotein convertase subtilisin-kexin type 9 inhibitors reduce lipoprotein(a) by approximately 20 to 30% and simultaneously significantly reduce low-density lipoprotein cholesterol. Therefore, in high-risk patients who require additional reduction in low-density lipoprotein cholesterol, these drugs may be particularly attractive because they also partially reduce the lipoprotein(a)-related component of risk. [41]

Nicotinic acid can reduce lipoprotein(a) by approximately 23 to 25%, but current guidelines do not consider it a preferred treatment for this specific problem, as its addition to statins in more recent studies did not provide the expected clinical benefit in terms of cardiovascular outcomes. Therefore, relying solely on a reduction in laboratory values without a proven improvement in prognosis is incorrect. [42]

Lipoprotein apheresis remains an option for a very limited group of severely ill patients. According to the National Lipid Association, in the United States, it is approved for patients with familial hypercholesterolemia, documented coronary or peripheral artery disease, lipoprotein(a) levels of 60 mg per deciliter or higher, and low-density lipoprotein cholesterol of 100 mg per deciliter or higher on maximal tolerated therapy. The method is effective, but expensive, labor-intensive, and not universally available. [43]

Specifically targeted drugs against lipoprotein(a) are being actively developed. Pelacasen and olpasiran are being studied in large cardiovascular outcome trials, and leposideran demonstrated a very significant and long-lasting reduction in concentrations in a 2025 study. However, the key question remains: not only must a reduction in the test result be proven, but also must it be demonstrated that this reduction actually reduces the incidence of heart attacks, strokes, and cardiovascular death. [44]

Table 7. How different approaches affect lipoprotein

Approach	Effect on lipoprotein(a)	Practical commentary
Statins	Usually they don't decrease it, sometimes they increase it slightly	Still necessary to reduce risk
Ezetimibe	Minimal or none	Helpful in lowering low-density lipoprotein cholesterol
Bempedoic acid	There is usually no significant influence	Used for general lipid indications
Proprotein convertase subtilisin-kexin type 9 inhibitors	Approximately minus 20 to 30%	Useful in high-risk patients
Nicotinic acid	Approximately minus 23 to 25%	Not considered a preferred option for this particular purpose.
Lipoprotein apheresis	Significant reduction, but the method is for limited indications	Used in selected severely ill patients
Pelakasen, olpaciran, ledisiran	A strong decline in research	For now, the results of outcome studies are of key importance

Table base: [45]

Special situations in children and in the family

In children, elevated lipoprotein(a) has a different practical significance than in adults. In childhood, it is less associated with established atherosclerosis and serves more as an early indicator of an inherent high risk that may manifest later. Moreover, in children, elevated lipoprotein(a) is also associated with ischemic stroke, especially if other prothrombotic factors are present. [46]

Selective screening in children is warranted in cases of familial hypercholesterolemia, premature cardiovascular events in close relatives, elevated lipoprotein(a) in first-degree relatives, and ischemic stroke of unknown cause. This approach avoids overburdening all children with screening, but allows for the early identification of families at truly high risk. [47]

Interestingly, lipoprotein(a) concentrations largely reach adult levels by around 5 years of age, although some data suggest that increases may continue into early adulthood. This explains why a single measurement in a child at risk can be informative, rather than simply a random "childhood number" that will later change completely. [48]

If high lipoprotein(a) is detected in a child, this should prompt testing of immediate family members. In practice, this result often proves the most convenient entry point to identifying a family's hereditary risk: the child may not yet have symptoms, but the family already has the opportunity to correct risk factors in adults and organize early prevention. [49]

Treatment for children with elevated lipoprotein(a) levels focuses primarily on controlling common risk factors, promoting a healthy lifestyle, preventing smoking, and closely monitoring any associated lipid metabolism disorders. Elevated lipoprotein(a) levels in a child do not automatically necessitate specific therapy, but they do make all other preventive measures significantly more important. [50]

Frequently Asked Questions

Are lipoprotein(a) and low-density lipoproteins the same thing?
No. Lipoprotein(a) is a lipoprotein-like particle similar to low-density lipoproteins but containing an additional apolipoprotein(a). Therefore, it is not the same as regular low-density lipoprotein cholesterol and carries additional information about hereditary risk. [51]

Should everyone have this test?
Current expert documents increasingly recommend at least one measurement for every adult, especially for accurate long-term risk assessment. However, the test has not yet become part of standard screening in routine practice. [52]

If normal cholesterol is normal, is high lipoprotein(a) still dangerous?
Yes. High lipoprotein(a) can increase risk even when the standard lipid profile appears relatively healthy. This is precisely its special value. [53]

Is it possible to lower lipoprotein(a) levels through diet and exercise?
Significant changes in the level itself are usually not possible, as it is largely genetically determined. However, diet, physical activity, smoking cessation, and weight control are still crucial, as they reduce overall cardiovascular risk. [54]

What result is considered high?
In modern practice, a threshold of 125 nmol per liter and above is often used as a high-risk zone. If a laboratory reports a result in mg per deciliter, a value of 50 or above is often used as a benchmark, but these units cannot be unconditionally converted to a constant coefficient. [55]

Why can't we simply convert mg/dL to nmol/L using a single formula?
Because the mass of lipoprotein(a) particles varies due to the variable structure of apolipoprotein(a). Therefore, a rigid conversion could distort the actual risk assessment. [56]

Should the test be repeated every year?
Usually not. Most people have relatively stable levels, so one measurement is often sufficient. Repeat testing is considered in the intermediate zone, after menopause, and for certain new conditions, such as chronic kidney disease or hypothyroidism. [57]

If lipoprotein(a) is high, should family members be tested?
Yes, it's a good idea, especially in first-degree relatives. Elevated lipoprotein(a) is inherited, so family screening can help identify other people at increased risk. [58]

Are there currently medications that specifically lower lipoprotein(a)?
In routine clinical practice, the primary focus is currently on reducing overall risk, primarily through active control of low-density lipoprotein cholesterol. Specific medications targeting lipoprotein(a) are in advanced stages of clinical trials. [59]

Does a child need this test?
Not all children. But in a child from a high-risk family, with familial hypercholesterolemia, a history of early vascular events in relatives, or with ischemic stroke of unknown cause, the test can be very useful. [60]

Conclusion

Serum lipoprotein(a) is not an "exotic additional test," but an important marker of hereditary cardiovascular risk. Its elevation is associated with atherosclerotic cardiovascular disease and aortic valve stenosis, and therefore the result is important for both the patient and their relatives. [61]

The practical purpose of analysis today is not so much to find a quick way to reduce the number itself, but rather to more accurately stratify risk and implement more proactive prevention. This is why high lipoprotein(a) levels should prompt more serious control of low-density lipoprotein cholesterol, blood pressure, diabetes, body weight, and tobacco use. [62]