Lipoprotein(a): The Inherited Cardiovascular Risk Factor Most Doctors Do Not Test

What Lp(a) Is and Why It Is Unique

Lipoprotein(a) is an LDL-like particle with an additional protein called apolipoprotein(a) — apo(a) — attached via a disulfide bond. This extra protein makes Lp(a) more atherogenic than standard LDL: it promotes inflammation in the arterial wall, interferes with clot breakdown (thrombolysis), and deposits in atherosclerotic plaques. Unlike virtually every other major cardiovascular risk factor, Lp(a) is almost entirely genetically determined — around 70–90% of individual variation is explained by the LPA gene on chromosome 6.

Reference Ranges and Risk Thresholds

Lp(a) Level	Risk Category
Below 30 mg/dL (below 75 nmol/L)	Normal — no additional risk
30–50 mg/dL (75–125 nmol/L)	Borderline — increased risk begins
Above 50 mg/dL (above 125 nmol/L)	High — significantly elevated cardiovascular risk
Above 180 mg/dL (above 430 nmol/L)	Very high — risk equivalent to familial hypercholesterolaemia

Units vary between labs — some report in mg/dL, others in nmol/L. Ensure you know which unit applies. Approximately 20% of the population has Lp(a) above 50 mg/dL; around 1 in 5 of those have levels above 180 mg/dL.

Why Lp(a) Is Clinically Important

Elevated Lp(a) is an independent risk factor for heart attack, ischaemic stroke, aortic valve stenosis, and peripheral artery disease — independent of LDL cholesterol, smoking, blood pressure, and other traditional risk factors. In large studies, Lp(a) above 50 mg/dL roughly doubles cardiovascular risk compared to low levels. In people with already elevated LDL, high Lp(a) multiplies risk rather than simply adding to it.

The Lifestyle Problem: Most Interventions Don't Work

Standard lipid-lowering interventions have minimal effect on Lp(a). Statins actually modestly increase Lp(a) in some people. PCSK9 inhibitors lower Lp(a) by approximately 20–30%, which is helpful but rarely brings very high levels into the normal range. Niacin reduces Lp(a) but is no longer recommended due to side effects outweighing benefits in clinical trials.

RNA-targeting therapies (specifically pelacarsen and olpasiran) in clinical trials show dramatic Lp(a) reductions of over 80% — these may become available as treatments in the near future.

What to Do If Your Lp(a) Is High

Since Lp(a) cannot be changed by lifestyle, the clinical response is to manage all other cardiovascular risk factors more aggressively. This means stricter LDL targets (many cardiologists target ApoB below 70 mg/dL in high-Lp(a) patients), blood pressure control, non-smoking, maintaining metabolic health, and potentially earlier use of lipid-lowering medication. Lp(a) is tested once — it does not change significantly over a lifetime. All first-degree relatives of someone with elevated Lp(a) should be tested.