Lp(a): The Heart Risk Marker Your Doctor Probably Isn't Testing

TL;DR

Lipoprotein(a), or Lp(a), is a genetically determined heart risk factor that affects roughly 1 in 5 people. It’s independent of LDL cholesterol, rarely tested on standard panels, and can’t be changed with diet or statins. Ask your doctor for a one-time Lp(a) test — knowing your number helps you manage overall risk more effectively.

You’ve probably had your cholesterol tested. Maybe you even know your LDL, HDL, and triglyceride numbers by heart. But there’s a marker that affects an estimated 1.5 billion people worldwide — and your doctor has likely never tested it.

It’s called lipoprotein(a), or Lp(a) for short. And it could change how you think about heart health.

What Is Lp(a)?

Lp(a) is a type of LDL particle with an extra protein attached to it called apolipoprotein(a). This addition makes the particle more inflammatory, more prone to clotting, and harder for your body to clear.

Think of regular LDL as a delivery truck. Lp(a) is the same truck, but with a sticky bumper that catches on artery walls as it passes through.

📚 Key Distinction

Lp(a) is not the same as LDL cholesterol. You can have low LDL and still have high Lp(a). Standard lipid panels don’t measure it — you need to specifically request it.

Why Should You Care?

The evidence is now strong enough that the American College of Cardiology calls Lp(a) an independent and causal risk factor for atherosclerotic cardiovascular disease. That means it contributes to heart disease on its own, regardless of your other risk factors.

A landmark 2024 study in the New England Journal of Medicine tracked nearly 28,000 women over 30 years. Those with the highest Lp(a) levels had a 33% higher risk of major cardiovascular events — even after accounting for LDL cholesterol and inflammation markers.

The National Lipid Association now recommends that every adult get their Lp(a) measured at least once. If your level is above 50 mg/dL (or 125 nmol/L), you’re considered high risk.

📊 Who's at Higher Risk?

About 20% of the global population has elevated Lp(a)
Levels are 70–90% genetically determined — diet and exercise have minimal direct effect
Concentrations vary by ethnicity, with the highest levels typically seen in people of African descent
Lp(a) levels remain remarkably stable over your lifetime
Women may have 17% higher levels after menopause

What Lp(a) Does in Your Body

High Lp(a) causes problems through three mechanisms:

Promotes atherosclerosis — Lp(a) particles deposit in artery walls and fuel plaque formation
Drives inflammation — The oxidised phospholipids on Lp(a) trigger inflammatory responses in blood vessels
Increases clotting risk — Apolipoprotein(a) has a structure similar to plasminogen (a clot-dissolving protein), potentially interfering with your body’s ability to break down clots

This triple threat is why Lp(a) is linked not just to heart attacks, but also to stroke and aortic valve disease.

The Keto Connection

If you’re on a keto or low-carb diet and your LDL went up, you’ve probably already dealt with some anxiety about your lipid numbers. Here’s where Lp(a) adds useful context:

Lp(a) and LDL are independent risk factors. A 2024 participant-level meta-analysis published in Circulation confirmed that Lp(a) predicts cardiovascular events independently of LDL cholesterol. This matters because it means looking at LDL alone gives you an incomplete picture.

⚠️ Statins and Lp(a)

Statins don’t lower Lp(a) — they may actually increase it slightly in some people. If you have elevated Lp(a), this is worth discussing with your doctor, since statin benefit calculations don’t account for Lp(a)-driven risk.

What Can You Actually Do?

Since Lp(a) is mostly genetic, you can’t diet or exercise it away. But knowing your number is still valuable:

1. Get Tested

Ask your doctor for a one-time Lp(a) test. Since levels are genetically stable, you typically only need to do this once. It’s a simple blood test, usually covered by insurance when requested.

2. Optimise Everything Else

If your Lp(a) is elevated, it becomes even more important to manage the risk factors you can control:

Keep blood pressure in range — high BP plus high Lp(a) compounds risk
Manage inflammation — a well-formulated keto or low-carb diet may help here
Don’t smoke — smoking amplifies Lp(a)-related risk
Stay active — regular exercise supports overall cardiovascular health
Consider omega-3s — while they don’t lower Lp(a) directly, they support cardiovascular health through other mechanisms

3. Watch the Emerging Therapies

The treatment landscape is changing fast. Several RNA-based drugs in clinical trials have shown the ability to reduce Lp(a) by 80–94%:

Lepodisiran — a single injection reduced Lp(a) by 94% for up to a year in Phase 2 trials
Olpasiran and Zerlasiran — achieved over 80% reduction with dosing every 3–6 months
Muvalaplin — an oral pill that reduced Lp(a) by 86% in Phase 2

The big question: will lowering Lp(a) actually reduce heart attacks and strokes? The Phase 3 HORIZON trial is expected to report results in 2026 and could be the definitive answer.

🎯 Key Takeaways

Get tested once — ask your doctor for an Lp(a) test, especially if you have a family history of heart disease
Don’t confuse it with LDL — they’re independent risk factors
You can’t change Lp(a) with diet — but you can optimise every other cardiovascular risk factor
New treatments are coming — RNA-based drugs may be available within a few years
Context matters — knowing your Lp(a) helps you and your doctor make smarter decisions about overall risk management

The Bottom Line

Lp(a) is one of those rare cases where the science is clear but clinical practice hasn’t caught up. It’s a proven, independent, causal risk factor for heart disease — yet most people have never heard of it, and most doctors don’t routinely test for it.

Whether you’re on keto, carnivore, or any other diet, your Lp(a) level is something worth knowing. It takes one blood test, one time, and the information could meaningfully change how you approach heart health.

Ask for the test at your next check-up. It might be the most important number you’ve never seen.