What Lp(a) is
Lipoprotein(a) — written Lp(a) and pronounced "L-P-little-a" — is a lipoprotein particle similar in structure to LDL but with an additional protein called apolipoprotein(a) (apo(a)) covalently attached via a disulfide bond to the ApoB molecule. This unique structure makes Lp(a) both atherogenic (drives arterial plaque formation like LDL) and thrombogenic (promotes blood clotting, because apo(a) structurally resembles plasminogen and may impair clot breakdown).
Lp(a) is the most important genetically driven cardiovascular risk factor after familial hypercholesterolaemia. Unlike LDL-C, which responds substantially to diet and medication, Lp(a) is almost entirely genetically determined.
The genetic nature of Lp(a)
Approximately 90% of a person's Lp(a) level is determined by variants in the LPA gene, which encodes the apo(a) protein. The number of "kringle IV type 2" repeats in apo(a) determines particle size and inversely correlates with plasma Lp(a) levels — smaller particles = higher levels = higher risk.
This genetic determination means: your Lp(a) level at age 25 is essentially your Lp(a) level at age 70. Diet, exercise, weight loss, and most supplements have minimal impact. This is why you only need to test Lp(a) once in your lifetime — unless you are specifically undergoing treatment aimed at lowering it.
Why it matters — the evidence for causality
Lp(a) is not just correlated with cardiovascular disease — it is causally linked, confirmed through Mendelian randomisation studies (natural genetic experiments that establish causality rather than correlation). The INTERHEART study, Copenhagen Heart Study, and multiple large meta-analyses confirm that elevated Lp(a) is an independent risk factor for:
- Coronary artery disease and myocardial infarction
- Ischaemic stroke
- Aortic valve stenosis — Lp(a) deposits in valve leaflets accelerating calcification
- Peripheral artery disease
The risk is dose-dependent and additive to other cardiovascular risk factors.
India-specific context
South Asian populations have higher average Lp(a) levels compared to European populations. This compounds the already elevated cardiovascular risk profile of Indians — who have higher rates of coronary artery disease at younger ages and lower LDL levels than Western counterparts. If you are South Asian, Lp(a) testing should be a standard part of your cardiovascular risk assessment.
Testing and interpretation
Two units are used: mg/dL and nmol/L. These are not directly interchangeable — different conversion factors exist across labs (not a simple multiplication). Request nmol/L where available, as it is the more standardised unit.
| Lp(a) Level | Risk Category | Interpretation | Action |
|---|---|---|---|
| <30 mg/dL (<75 nmol/L) | Low risk | Lp(a) not a significant risk driver | No specific action; standard CVD prevention |
| 30–50 mg/dL (75–125 nmol/L) | Borderline elevated | Moderately increased risk; warrants attention | Optimise all other CVD risk factors; discuss with physician |
| 50–100 mg/dL (125–250 nmol/L) | High risk | Significant independent cardiovascular risk | Aggressive optimisation of ApoB, BP, glucose, CRP; consider PCSK9 inhibitor |
| >100 mg/dL (>250 nmol/L) | Very high risk | Very high cardiovascular and thrombotic risk | Cardiologist referral; PCSK9 inhibitor; watch for trial eligibility for Lp(a)-specific therapies |
What lowers Lp(a) — the honest picture
Most interventions that effectively lower LDL-C have minimal or no impact on Lp(a). Here is the evidence:
- Statins — do NOT lower Lp(a); may raise it slightly (5–10%)
- Diet and lifestyle — minimal effect; not a meaningful lever
- PCSK9 inhibitors (evolocumab, alirocumab) — lower Lp(a) by 25–30% as a secondary effect; primarily prescribed for LDL-C reduction
- Niacin (vitamin B3) at 1–2g/day — lowers Lp(a) 20–30%; fallen out of favour due to side effects and lack of cardiovascular outcome benefit in trials despite Lp(a) reduction
- RNA-targeting therapies (pelacarsen, olpasiran, zerlasiran) — phase 3 trials showing 80–90% Lp(a) reduction; not yet approved; transformative when available
- Lipoprotein apheresis — physically removes Lp(a) and LDL; very effective but only available in specialised centres
If your Lp(a) is elevated, the focus shifts to aggressively optimising everything else you can control — ApoB, blood pressure, blood glucose, inflammation (hsCRP), and smoking cessation. Lp(a) is a risk modifier, not a death sentence. Each modifiable risk factor you optimise directly reduces the absolute risk from elevated Lp(a).
How often to test
Once in your lifetime is sufficient for most people — Lp(a) levels are genetically stable. Exceptions: if you are enrolled in a clinical trial or receiving PCSK9 inhibitor treatment specifically targeting Lp(a) reduction, retest annually to confirm response.
Frequently asked questions
What is Lp(a) and how does it affect heart risk?
Lp(a) is an LDL-like particle with extra thrombogenic protein attached. It is both atherogenic and clot-promoting. Elevated Lp(a) is a genetically determined, independent causal cardiovascular risk factor confirmed by Mendelian randomisation. About 20% of people have elevated levels — higher in South Asians.
Can I lower Lp(a) naturally?
Honestly, very little can lower it. Diet and exercise have minimal effect. Statins don't lower it. PCSK9 inhibitors reduce it 25–30%. Niacin reduces it 20–30% but has side effects. New RNA therapies show 80–90% reduction in trials but aren't yet approved. Focus on optimising all other modifiable risk factors.
How much does the Lp(a) test cost in India?
₹600–1,200 at major labs (SRL, Metropolis, Dr Lal PathLabs). Request results in nmol/L where possible — more standardised than mg/dL which uses inconsistent conversion factors between labs.
Should I take aspirin if my Lp(a) is high?
Aspirin doesn't lower Lp(a) but may reduce thrombotic risk. The benefit/risk balance of aspirin for primary prevention with elevated Lp(a) is person-specific — requires physician evaluation. Don't self-prescribe.