Cardio IQ Lipoprotein Fractionation (Ion Mobility) Biomarker Testing
It measures LDL and HDL particle number and size to refine cardiovascular risk beyond standard cholesterol, with easy ordering and Quest lab access via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
This test looks past “total cholesterol” and measures the particles that actually carry cholesterol through your bloodstream. It uses ion mobility to count lipoprotein particles and describe their size distribution, which can help explain why your standard lipid panel looks “fine” but your risk picture still feels unclear.
You will usually see results like LDL particle number (LDL-P), HDL particle number (HDL-P), and the amount of small or large LDL particles. These details can matter because two people with the same LDL-C can have very different numbers of LDL particles.
Your result is most useful when you interpret it alongside other risk markers (like triglycerides, ApoB, Lp(a), blood pressure, and glucose/insulin patterns) and your personal history. This test supports clinician-directed care and shared decision-making; it is not a standalone diagnosis.
Do I need a Cardio IQ Lipoprotein Fractionation (Ion Mobility) test?
You may want this test if you are trying to clarify cardiovascular risk when a standard lipid panel does not match your situation. Common examples include a strong family history of early heart disease, a prior abnormal coronary calcium score, metabolic syndrome features (higher triglycerides, low HDL-C, abdominal weight gain), or persistently “borderline” LDL-C where you and your clinician are deciding how aggressive to be.
This test can also be helpful if you have already made lifestyle changes or started lipid-lowering therapy and you want to know whether the number of atherogenic particles is improving, not just the cholesterol concentration. Particle measures can shift even when LDL-C changes only modestly.
You might not need ion mobility fractionation if your risk is clearly low, your standard lipid panel and ApoB are already optimal, and you have no major risk enhancers. In that case, simpler tests may be enough for routine monitoring.
If you are pregnant, acutely ill, or have had a recent major change in diet, weight, or medications, consider timing the test so it reflects your stable baseline. Your clinician can help you decide what to order and how to act on the results.
This is a laboratory-developed test performed in a CLIA-certified lab; results should be interpreted in clinical context and are not a diagnosis by themselves.
Lab testing
Order Cardio IQ Lipoprotein Fractionation (Ion Mobility) through Vitals Vault when you want an advanced look beyond standard cholesterol.
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Get this test with Vitals Vault
Vitals Vault makes it straightforward to order advanced lipid testing when you want more detail than a basic cholesterol panel. You can choose Cardio IQ Lipoprotein Fractionation (Ion Mobility) as a focused add-on or as part of a broader cardiometabolic workup, depending on what question you are trying to answer.
After your blood draw, you get clear results you can share with your clinician. If you want help making sense of patterns—like high LDL-P with normal LDL-C, or a shift toward smaller LDL particles—you can use PocketMD to ask practical follow-up questions and plan what to check next.
If you are tracking progress, Vitals Vault also supports repeat testing so you can compare trends over time rather than relying on a single snapshot.
- Order online and complete your blood draw through the Quest network
- PocketMD helps you turn results into next-step questions for your clinician
- Designed for trending so you can retest after lifestyle or medication changes
Key benefits of Cardio IQ Lipoprotein Fractionation (Ion Mobility) testing
- Clarifies risk when LDL-C looks acceptable but your overall risk profile is not.
- Measures LDL particle number (LDL-P), which can better reflect atherogenic burden than LDL-C in some people.
- Shows LDL size distribution, including the proportion of small, dense LDL particles.
- Adds context to high triglycerides, low HDL-C, insulin resistance, and metabolic syndrome patterns.
- Helps you and your clinician monitor response to lifestyle changes or lipid-lowering therapy beyond cholesterol totals.
- Supports more personalized decisions about which companion tests to add (ApoB, Lp(a), hs-CRP, A1c, fasting insulin).
- Creates a baseline you can trend over time, with PocketMD available to interpret changes and plan retesting.
What is Cardio IQ Lipoprotein Fractionation (Ion Mobility)?
Cardio IQ Lipoprotein Fractionation (Ion Mobility) is an advanced lipid test that characterizes the particles (lipoproteins) that transport cholesterol and triglycerides in your blood. Instead of focusing only on how much cholesterol is inside those particles (like LDL-C and HDL-C), it counts particles and describes their size distribution.
Ion mobility is a measurement approach that separates particles based on their physical size and charge as they move through an electric field. In practical terms, it can estimate how many LDL particles you have (LDL-P), how many HDL particles you have (HDL-P), and how those particles are distributed across size ranges (for example, small vs large LDL).
This matters because atherosclerosis risk is driven by how many atherogenic particles enter and linger in the artery wall over time. If each particle carries less cholesterol than average, your LDL-C can look “normal” even when particle number is high. Conversely, some people carry more cholesterol per particle and can have higher LDL-C with a less concerning particle count.
Your report is best interpreted together with standard lipids, ApoB (a direct count proxy for atherogenic particles), triglycerides, and your overall risk factors (blood pressure, smoking status, diabetes, family history, and imaging when appropriate).
LDL-C vs LDL-P: why the difference can matter
LDL-C tells you the amount of cholesterol carried within LDL particles, while LDL-P estimates how many LDL particles are circulating. When LDL-C and LDL-P disagree (often called discordance), LDL-P can help explain why risk seems higher or lower than expected from LDL-C alone.
What “small, dense LDL” means in plain language
Smaller LDL particles are often seen with higher triglycerides and insulin resistance. They are not automatically “bad” in isolation, but a pattern of many LDL particles plus a shift toward smaller sizes can signal a more atherogenic environment that benefits from addressing triglycerides, weight, glucose control, and overall particle burden.
What do my Cardio IQ Lipoprotein Fractionation (Ion Mobility) results mean?
Low particle numbers or fewer small LDL particles
Lower LDL particle number generally suggests fewer atherogenic particles circulating, which is often favorable when it aligns with other markers like ApoB, non-HDL-C, and triglycerides. A lower proportion of small LDL particles can also fit with better metabolic health, especially when triglycerides are not elevated. However, “low” should still be interpreted with your overall risk, because factors like Lp(a), inflammation, or existing plaque can change the picture. If your LDL-P is low but you have other major risk enhancers, your clinician may still recommend additional evaluation.
In-range (optimal) particle profile
An in-range LDL-P with a balanced size distribution usually means your cholesterol transport is not showing an obvious particle-driven risk signal. This is most reassuring when triglycerides are controlled, HDL measures are reasonable, and ApoB/non-HDL-C also look good. If you are using lifestyle changes or medication, an optimal pattern can confirm that your approach is improving the underlying particle burden, not just the headline cholesterol number. Your clinician may still tailor targets based on your personal risk level and any prior imaging.
High LDL particle number and/or a shift toward smaller LDL
A higher LDL-P suggests more atherogenic particles circulating, which can increase the chance that particles enter the artery wall over time. A pattern that includes more small LDL particles often travels with higher triglycerides, lower HDL-C, insulin resistance, or weight gain around the midsection. This does not mean you have heart disease, but it is a signal to address drivers such as diet quality, alcohol intake, activity level, sleep, and cardiometabolic health—and to discuss whether medication is appropriate. Many people also benefit from checking ApoB and Lp(a) to understand whether particle burden is coming from common metabolic factors, inherited risk, or both.
Factors that influence lipoprotein particle results
Recent weight change, dietary shifts (especially carbohydrate and alcohol intake), and exercise patterns can change triglycerides and particle size distribution within weeks. Medications such as statins, ezetimibe, PCSK9 inhibitors, fibrates, omega-3 prescriptions, and some hormones can alter LDL-P and size patterns, so timing matters when you are monitoring response. Thyroid status, uncontrolled diabetes, kidney disease, and inflammatory states can also affect lipids and particle measures. For the cleanest trend, try to test when you are stable and use the same lab method over time.
Similar tests to consider
Frequently Asked Questions
Do I need to fast for an ion mobility lipoprotein fractionation test?
Many clinicians prefer a 9–12 hour fast for advanced lipid and particle testing because triglycerides can rise after meals and influence particle patterns. If your order instructions say fasting is required, follow them. If not, ask your clinician whether fasting makes sense for your situation, especially if triglycerides are a key concern.
Is LDL-P the same as ApoB?
They are related but not identical. ApoB is a protein found on most atherogenic particles (including LDL and others), so ApoB is often used as a practical proxy for total atherogenic particle number. LDL-P focuses specifically on LDL particles; depending on your lipoprotein profile, ApoB and LDL-P can track closely or show differences that add context.
What is a “small dense LDL” result and should I worry?
“Small dense LDL” refers to smaller LDL particles that are commonly seen with higher triglycerides and insulin resistance. It is not a diagnosis and it is not the only thing that matters. If small LDL is elevated along with high LDL-P, high triglycerides, or high ApoB, it is a stronger signal to address metabolic drivers and overall particle burden with your clinician.
How often should I retest LDL particle number and size?
If you are making a change—such as starting or adjusting medication, changing diet, or losing weight—many people retest in about 8–12 weeks to see a stable response. For longer-term monitoring when things are stable, retesting every 6–12 months is common. Your clinician may recommend a different interval based on your risk level.
Can my LDL-C be normal but LDL-P be high?
Yes. This is a common reason people order particle testing. If each LDL particle carries less cholesterol than average, LDL-C can look normal even when the number of particles is high, which may better reflect atherogenic exposure over time.
What should I do if my LDL-P is high?
Start by reviewing the full context: triglycerides, HDL-C, non-HDL-C, ApoB (if available), blood pressure, glucose/A1c, family history, and any imaging results. Then focus on drivers you can change—diet quality, alcohol intake, activity, sleep, and weight—and discuss with your clinician whether medication or additional testing (like Lp(a) or hs-CRP) would change your plan. The goal is usually to reduce overall atherogenic particle burden and improve cardiometabolic health, not to chase a single number.