Instant Insights: Lipoprotein Fractionation for Personalized Risk Assessment

Instant insights: Lipoprotein fractionation for personalized risk assessment

[00:00:00] Welcome to Healthier World with Quest Diagnostics. Our goal is to prompt action from insight as we keep you up to date on current clinical and diagnostic topics in cardiovascular, metabolic, endocrine, and wellness medicine.

Maeson: In this special episode of Healthier World, designed to give you instant insights, we dive into advanced lipid testing going beyond a standard lipid panel in order to lead to more informed decision making.

You've probably heard of LDL-C and APA lipoprotein B, but what happens when we dig even deeper? Today, we will explore two powerful tools used to look at lipoprotein fractionation, iron Mobility, and Nuclear magnetic resonance, or NMR. We'll look at how these tests work, the similarities and differences, and how they can uncover hidden risks for cardiovascular disease. So let's dive in.

We're seeing a clear chain reaction.

[00:01:00] Obesity is leading to more cases of diabetes, and that's driving the rates of cardiovascular disease. Thus, it's imperative that we take a closer look at the tools we're using to predict cardiovascular disease risk. Right now, LDL-C is the standard marker, but it doesn't always tell the whole story, especially in people with metabolic disease.

It is time we dug a little deeper to find a way to assess cardiovascular disease risk that better reflects what's really going on. The key thing to keep in mind here is that lipids like cholesterol and triglycerides don't mix freely with blood, and they need to be packaged into particles to be transported around our body. Many individuals who experience obesity and diabetes display LDL Discordance, meaning that they aren't good at packaging that LDL-C into particles while their LDL-C might be normal, their particle count is high which increases their risk for cardiovascular disease.

Lipid fractionation is a tool used to sort lipoproteins by size and density, which can be done [00:02:00] using two methodologies, iron mobility and NMR.

Ion mobility separates particles by how they move through a gas-based chamber based on size and shape and counts the number of lipid particles directly.

NMR is a tool that measures the quantity by deconvoluting the signal.

They are different methodologies with different reported analytes and reference ranges. Each methodology was verified and established in the lab using slightly different populations and based on different risk cut points established in the literature. So while some analytes may be the same, results must be interpreted based on the relative risk range for that particular assay.

Let's dive into some of the specifics on each analyte. Provided by each methodology, each fractionation method gives you the quality and quantity of particles.

The first and most important value to assess in both NMR and ION mobility. Is LDL particle number. which is reflected by an LDLP, in NMR, [00:03:00] and an LDL particle number and ion mobility. This is the quantity piece where LDL particles count the number of LDL lipoproteins that are required to carry around your LDL-C. Keep in mind that risk tracks with particles. Thus, if an LDL particle number is high, the risk for cardiovascular disease is high. LDL particle number will help you better understand who is at risk for cardiovascular disease.

When you have a patient with a normal LDL-C in a high LDL-P, that's what we call lipid discordance, and that's often driven by insulin resistance, metabolic dysfunction, chronic kidney disease, diabetes, lipid lowering medications, and even hormone changes like hypothyroidism.

So this is the quantity piece, and both methods, NMR and ION Mobility will give you that information.

Each method also offers LDL lipid particle quality, which is another key indicator of risk.

When a patient has small [00:04:00] LDL particles. You can use these values to support your analysis of the LDL particle number and usually they correlate if a patient has a lot of LDL particles in circulation, they tend to have smaller and denser particles since each particle tends to have less cholesterol in them and therefore you need more in circulation.

Iron mobility reflects this as an LDL small in an LDL medium, whereas NMR gives you LDL small in the average LDL size. each methodology also gives you information on the quality and quantity of HDL particles.

HDL picks up the excess cholesterol from the periphery and carries it back to the liver for repackaging and disposal. So it's important to know how many HDLs you have in circulation, and that's reflected by HDLP and HDL particle number.

Maeson: Additionally, if one HDL particle is more full than the other, then we can consider that one more efficient. The way we can assess this is by looking at HDL large. How many of [00:05:00] these HDL particles are large and efficiently packaged? And this is a surrogate marker for the efficiency of HDL at cleaning up cholesterol.

And data suggests that HDL large is cardioprotective. We want more HDL in circulation and higher numbers of HDL large in circulation. HDL Particle number details like particle number enlarge HDL is included in both fractionation methods.

Additional insights that can be taken from lipoprotein fractionation. NMR Include information on VLDL. Now v LDLs. Largely carry triglycerides. So if these particles are large and overstuffed with triglycerides, these patients typically end up with dysfunctional cholesterol carrying LDL particles as well.

Thus, we don't want too many large VLDL particles in circulation. The VLDL information on the NMR includes VLDL particle number The number of large VLDL particles in circulation and the average VLDL size additional analytes captured by ION mobility [00:06:00] gives you more information about the LDL particle, including LDL pattern and LDL peak size.

LDL pattern reflects either pattern A, which correlates with large and fluffy particles. Or a pattern B, which correlates with small and dense particles. So to summarize, both ION mobility and NMR are methods to assess lipoprotein fractionation.

NMR includes information on v LDLs, HDLs, and LDLs, including LDL, small and LDLP.

Ion mobility includes HDL information and information on LDLs, including LDL Peak Size Pattern LDL Small and LDL particle number.

The results must be interpreted based on the relative risk range for that particular assay. For example, LDL particle number, which is included in both assays, has varying risk cut points based on the literature. NMR considers individuals with a lower 20th percentile. Of LDL particle number to be in the low-risk category, and the top 80th percentile [00:07:00] to be considered in the

high risk category where ion mobility splits these groups into thirds, considering the lowest one. Third, the low-risk group, and the highest one. Third, the high-risk group. However, NMR and ION Mobility will both give you the most important values when it comes to fractionation, LDL, particle number and small LDL-P.

Going beyond a standard lipid panel can be incorporated into clinical practice with these two powerful lipoprotein fractionation tools, iron mobility and NMR. Both methodologies represent a shift toward more informed decision making, delivering a more accurate and data-driven personalized care approach.

That's a wrap on this episode of Healthier World with Quest Diagnostics. Please follow us on your favorite podcast app and be sure to check out Quest Diagnostics Clinical Education Center for more resources, including educational webinars and research [00:08:00] publications.

Thank you for joining us today as we work to create a healthier world, one life at a time.