Lab Reference Library / Lp-PLA2 Inflammation & Cardiovascular

Lp-PLA2

Q: What is Lp-PLA2?

Lp-PLA2 (Lipoprotein-Associated Phospholipase A2), also called the PLAC test, is an enzyme produced by macrophages inside arterial plaques. Unlike hs-CRP, which reflects general systemic inflammation, Lp-PLA2 specifically reflects active inflammation within atherosclerotic plaques, making it a more targeted cardiovascular risk marker. Elevated Lp-PLA2 is independently associated with increased risk of heart attack and stroke.

Q: What is the optimal Lp-PLA2 level?

In functional medicine, an Lp-PLA2 mass below 100 ng/mL is considered optimal. The standard reference range defines elevated risk above 200 ng/mL. Values between 100 and 200 ng/mL are borderline and warrant attention in patients with other cardiovascular risk factors including elevated ApoB, hs-CRP, or homocysteine.

Q: What is the difference between Lp-PLA2 and hs-CRP?

hs-CRP reflects global systemic inflammation and can be elevated by any inflammatory process including infection, autoimmune disease, or physical injury. Lp-PLA2 is specifically produced by macrophages within arterial plaques and reflects vascular-specific inflammation, making it a more targeted cardiovascular risk marker. In patients with elevated hs-CRP, Lp-PLA2 helps determine whether the inflammation is primarily vascular or systemic in origin.

Q: What causes high Lp-PLA2?

Elevated Lp-PLA2 is primarily driven by atherosclerotic plaque activity, oxidized LDL (which activates macrophages in arterial walls), insulin resistance and metabolic syndrome, smoking (a major independent driver of vascular inflammation), elevated LDL particle count (ApoB), and chronic systemic inflammation that promotes plaque formation and destabilization.

Q: How do you lower Lp-PLA2?

The most effective interventions target vascular inflammation directly: smoking cessation (one of the most impactful single interventions), statins (which reduce Lp-PLA2 activity beyond their LDL-lowering effect), reducing oxidized LDL through antioxidant-rich nutrition, omega-3 fatty acids (EPA and DHA reduce vascular inflammation), addressing insulin resistance, and optimizing ApoB alongside hs-CRP. Darapladib, a specific Lp-PLA2 inhibitor, was studied in clinical trials but did not demonstrate clinical event reduction.

Lipoprotein-Associated Phospholipase A2 · PLAC Test

Reference range, optimal functional medicine levels, and why Lp-PLA2 is the most specific vascular inflammatory marker available, measuring active inflammation inside arterial plaques rather than systemic inflammation, and independently predicts cardiovascular events beyond LDL and hs-CRP.

Most SearchedCardiovascular Risk

Standard Range< 200 ng/mL

FM Optimal< 100 ng/mL

Fasting RequiredNo

Unitsng/mL

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Category: Inflammation & Cardiovascular | Also known as: Lipoprotein-Associated Phospholipase A2, PLAC Test | Sample: Serum (fasting not required)

1. What This Test Measures

Lp-PLA2 (Lipoprotein-Associated Phospholipase A2) is an enzyme produced predominantly by macrophages that have infiltrated atherosclerotic plaques within arterial walls. It hydrolyzes oxidized phospholipids in LDL particles, generating lysophosphatidylcholine and oxidized free fatty acids, both of which are potently pro-inflammatory and directly contribute to plaque vulnerability and progression.

The critical distinction between Lp-PLA2 and other cardiovascular inflammatory markers like hs-CRP is specificity:

hs-CRP is a general acute-phase protein produced by the liver in response to any inflammatory stimulus, whether vascular, infectious, autoimmune, or traumatic. An elevated hs-CRP could reflect a sprained ankle or active plaque as readily as cardiovascular disease.
Lp-PLA2 is produced specifically within arterial plaques and circulates primarily bound to LDL particles. Elevated Lp-PLA2 reflects active inflammation within the arterial wall itself, making it the most vascular-specific inflammatory marker available in clinical practice.

The enzyme is also known as the PLAC test (Phospholipase A2 Associated). It has been FDA-cleared for cardiovascular risk assessment and is the only biomarker specifically measuring inflammation within atherosclerotic plaques rather than general systemic inflammation.

2. Why This Test Matters

Independent cardiovascular risk predictor: multiple large prospective studies including the ARIC study and the West of Scotland Coronary Prevention Study (WOSCOPS) demonstrated that elevated Lp-PLA2 independently predicts coronary heart disease, fatal myocardial infarction, and ischemic stroke, even after adjustment for traditional risk factors including LDL, blood pressure, smoking, and diabetes.
Vulnerable plaque identification: Lp-PLA2 is especially valuable for identifying "vulnerable" plaques at high risk of rupture. These thin-capped, inflammation-rich plaques are the direct cause of most acute coronary events. Lp-PLA2 provides a window into plaque biology that LDL and even ApoB cannot.
Stroke risk assessment: Lp-PLA2 is particularly strongly associated with ischemic stroke driven by carotid atherosclerosis. The Atherosclerosis Risk in Communities (ARIC) study found that Lp-PLA2 mass was a stronger predictor of ischemic stroke than hs-CRP.
Risk stratification beyond LDL: a patient with "normal" LDL of 105 mg/dL but Lp-PLA2 of 280 ng/mL has a very different actual cardiovascular risk profile than the LDL alone would suggest. Lp-PLA2 captures the inflammatory vulnerability of existing plaques, which LDL particle count alone cannot.
Combination power with ApoB and hs-CRP: the combination of elevated ApoB (high atherogenic particle count), elevated hs-CRP (systemic inflammation), and elevated Lp-PLA2 (active vascular plaque inflammation) represents one of the highest-risk cardiovascular profiles identifiable on a standard advanced panel.

3. Standard Lab Reference Range

Lp-PLA2 Mass	Conventional Risk Classification
Below 200 ng/mL	Standard reference: lower risk zone
200 to 235 ng/mL	Borderline elevated: moderate risk
Above 235 ng/mL	Elevated: higher cardiovascular risk

Note: Reference ranges and cutoffs vary by assay (mass vs. activity). The functional medicine perspective establishes a lower optimal target than the conventional threshold, consistent with the principle that optimal is not merely the absence of high risk but the presence of optimal arterial health.

4. Optimal Functional Medicine Range

Lp-PLA2 Level	Functional Interpretation
Below 100 ng/mL	Optimal: minimal vascular inflammatory activity
100 to 150 ng/mL	Low borderline: monitor with other CV risk markers
150 to 200 ng/mL	Borderline: investigate with complete cardiovascular panel
200 to 235 ng/mL	Elevated: active vascular inflammation; comprehensive intervention indicated
Above 235 ng/mL	Significantly elevated: high vascular risk; aggressive cardiovascular risk reduction required

5. Symptoms Associated With Elevated Lp-PLA2

Like most cardiovascular risk markers, elevated Lp-PLA2 is typically completely asymptomatic until a clinical event occurs. Atherosclerotic plaque inflammation accumulates silently over decades. Warning signs and associated findings that should prompt Lp-PLA2 testing include:

High Lp-PLA2 Associated Findings

Usually asymptomatic until a cardiovascular event occurs
Often found alongside elevated ApoB and hs-CRP
Associated with elevated LDL, particularly small dense LDL pattern B
Insulin resistance and metabolic syndrome markers
Heavy smoking history
Strong family history of premature coronary artery disease or stroke
Carotid intima-media thickness (CIMT) abnormality
Coronary calcium scoring (CAC) showing calcified plaques

Lp-PLA2 vs. hs-CRP: Clinical Distinction

Elevated Lp-PLA2 with normal hs-CRP: vascular-specific inflammation without systemic burden; highest specificity for plaque activity
Elevated hs-CRP with normal Lp-PLA2: systemic inflammation (infection, autoimmune, etc.) without primary vascular source
Both elevated: active vascular inflammation with systemic inflammatory amplification; highest cardiovascular event risk profile
Both normal: lowest vascular inflammatory risk; complete reassurance on inflammatory cardiovascular pathways

6. What Causes Elevated Lp-PLA2

Atherosclerotic plaque burden: the primary driver; Lp-PLA2 is produced directly by macrophages within plaques; more extensive or more active plaques produce more enzyme
Oxidized LDL: oxidized LDL activates macrophages in arterial walls and is the primary substrate for Lp-PLA2 activity; addressing oxidized LDL is central to lowering Lp-PLA2
Smoking: one of the most powerful independent drivers of vascular Lp-PLA2 elevation; smoking cessation produces measurable Lp-PLA2 reduction
Insulin resistance and metabolic syndrome: promotes atherogenic LDL particle profile and vascular inflammation simultaneously
High ApoB and small dense LDL: small dense LDL particles penetrate arterial walls more easily and are more readily oxidized, directly activating Lp-PLA2-producing macrophages
Elevated hs-CRP: systemic inflammation amplifies vascular inflammatory signaling and macrophage activation within plaques
Sedentary lifestyle: physical inactivity promotes vascular inflammation through multiple pathways
Processed food and seed oil-heavy diet: drives oxidative stress and small dense LDL formation

7. How to Improve This Marker

Nutrition

Mediterranean diet: the most evidence-based dietary pattern for reducing vascular inflammation and Lp-PLA2
Increase antioxidant-rich foods: berries, dark leafy greens, extra-virgin olive oil; reduce oxidized LDL substrate
Replace seed oils (corn, soybean, sunflower) with olive oil and avocado oil
Reduce refined carbohydrates and added sugars; drives small dense LDL and insulin resistance
Increase soluble fiber (oats, legumes, psyllium): lowers LDL particle count and atherogenic burden
Eliminate trans fats completely; directly raise LDL and vascular inflammation

Lifestyle

Smoking cessation: the single highest-impact intervention for Lp-PLA2 reduction in current smokers; measurable reduction within weeks
Regular aerobic exercise (150+ minutes per week): reduces vascular inflammation, improves endothelial function, and lowers oxidized LDL
Weight loss: reducing visceral adiposity decreases the atherogenic LDL profile driving Lp-PLA2 elevation
Address insulin resistance: improving insulin sensitivity reduces small dense LDL formation and vascular inflammatory signaling
Reduce chronic psychological stress: cortisol promotes vascular inflammation through multiple mechanisms

Targeted Support

Statins: reduce Lp-PLA2 activity beyond their LDL-lowering effect, likely through plaque stabilization and anti-inflammatory mechanisms; most potent pharmacological Lp-PLA2 reducers
EPA and DHA fish oil (2 to 4g daily): reduces vascular inflammation and lowers Lp-PLA2 through multiple anti-inflammatory pathways; particularly high-EPA formulations
Niacin: reduces both LDL particle count and Lp-PLA2 activity; use under physician supervision
Vitamin E (tocotrienol form): reduces LDL oxidation, the primary Lp-PLA2 substrate
Berberine: improves insulin sensitivity and reduces atherogenic dyslipidemia; indirectly lowers Lp-PLA2 drivers
PCSK9 inhibitors: dramatically lower ApoB and atherogenic particle burden; associated with significant Lp-PLA2 reduction

8. Related Lab Tests

hs-CRPSystemic Inflammation Companion

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ApoBAtherogenic Particle Count

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HomocysteineVascular Endothelial Damage Marker

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Oxidized LDLPrimary Lp-PLA2 Substrate

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Omega-3 IndexAnti-inflammatory Reduction of Lp-PLA2

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Fasting InsulinIR Drives Atherogenic LDL Profile

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9. When Testing Is Recommended

Any individual with intermediate cardiovascular risk where additional risk stratification beyond LDL is needed
Patients with "normal" LDL cholesterol but other cardiovascular risk factors; Lp-PLA2 identifies plaque activity LDL cannot reveal
Strong family history of premature coronary artery disease or stroke
Known atherosclerosis (coronary calcium score above 0, CIMT abnormality) to assess plaque inflammatory activity
Elevated ApoB or hs-CRP; Lp-PLA2 completes the vascular inflammatory picture
Smokers or former smokers; smoking is the primary non-lipid driver of Lp-PLA2 elevation
Metabolic syndrome and insulin resistance with cardiovascular concern
Monitoring treatment response to statins, fish oil, or lifestyle interventions targeting vascular inflammation
Any comprehensive functional medicine cardiovascular panel

10. Clinical Perspective

Clinical Perspective

Lp-PLA2 is the marker that tells you what is actually happening inside the plaque, not just how much plaque there is or how inflamed the system is generally. I include it in every advanced cardiovascular panel because the combination of ApoB, hs-CRP, and Lp-PLA2 gives me a three-dimensional picture of cardiovascular risk that no single marker can provide alone. I've had patients with LDL of 95, hs-CRP of 0.6, and Lp-PLA2 of 260 who by every standard risk assessment appear low risk, but the Lp-PLA2 is telling me their plaques are biologically active and inflammatory. That's the patient who needs to be taking fish oil seriously, doing meaningful aerobic exercise, and thinking about statin therapy regardless of what the standard lipid panel shows. Lp-PLA2 is one of the most underutilized risk stratification tools we have.

Brian Lamkin, DO | Founder, The Lamkin Clinic | Edmond, Oklahoma

11. Frequently Asked Questions

What is Lp-PLA2?

Lp-PLA2 (Lipoprotein-Associated Phospholipase A2), also called the PLAC test, is an enzyme produced by macrophages inside arterial plaques. Unlike hs-CRP, which reflects general systemic inflammation, Lp-PLA2 specifically reflects active inflammation within atherosclerotic plaques, making it the most vascular-specific inflammatory marker available. Elevated Lp-PLA2 is independently associated with increased risk of heart attack and ischemic stroke.

What is the optimal Lp-PLA2 level?

In functional medicine, an Lp-PLA2 mass below 100 ng/mL is considered optimal. The standard reference defines elevated risk above 200 to 235 ng/mL. Values between 100 and 200 ng/mL are borderline and warrant attention in patients with other cardiovascular risk factors including elevated ApoB, hs-CRP, or homocysteine.

What is the difference between Lp-PLA2 and hs-CRP?

hs-CRP reflects global systemic inflammation and can be elevated by any inflammatory process including infection, autoimmune disease, or injury. Lp-PLA2 is specifically produced by macrophages within arterial plaques and reflects vascular-specific inflammation. In patients with elevated hs-CRP, Lp-PLA2 helps determine whether the inflammation is primarily vascular (cardiovascular concern) or systemic in origin (broader investigation needed).

What causes high Lp-PLA2?

Elevated Lp-PLA2 is primarily driven by atherosclerotic plaque activity, oxidized LDL (which activates macrophages in arterial walls), smoking (a major independent driver), insulin resistance and metabolic syndrome, elevated ApoB and small dense LDL particle predominance, and chronic systemic inflammation that promotes plaque formation and destabilization.

How do you lower Lp-PLA2?

The most effective interventions target vascular inflammation directly: smoking cessation (the highest-impact single intervention for smokers), statins (which reduce Lp-PLA2 activity beyond their LDL-lowering effect), omega-3 fatty acids (2 to 4g daily of combined EPA and DHA), addressing insulin resistance and metabolic syndrome, Mediterranean diet, and regular aerobic exercise. PCSK9 inhibitors significantly reduce Lp-PLA2 in high-risk patients by dramatically lowering atherogenic particle burden.

Should I test Lp-PLA2 if my LDL is normal?

Yes. Normal LDL cholesterol does not exclude active plaque inflammation. Lp-PLA2 adds independent risk information beyond LDL, ApoB, and hs-CRP by revealing the inflammatory biology of existing plaques. Patients with normal LDL but elevated Lp-PLA2 have significantly elevated cardiovascular event risk that would be entirely missed by standard lipid panel assessment.

Content authored and clinically reviewed by Brian Lamkin, DO, founder of The Lamkin Clinic in Edmond, Oklahoma. Brian Lamkin, DO has 25+ years of experience in functional and regenerative medicine. This page reflects current functional medicine practice standards and is updated as new clinical evidence becomes available.

Your LDL is normal. Your plaques may not be.

Standard lipid panels miss vascular inflammation. Schedule a consultation for a complete cardiovascular risk panel including Lp-PLA2, ApoB, and hs-CRP.

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Medical Disclaimer: This content is provided for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Lab interpretation should always be performed in clinical context by a qualified healthcare provider. Reference ranges and optimal targets may vary based on individual patient history, clinical presentation, and laboratory methodology. Schedule a consultation to discuss your specific results with Dr. Lamkin.