What is Lp(a) and why hasn't my doctor tested it?

Lp(a) (lipoprotein(a)) is an LDL-like particle with an additional apo(a) protein attached, is genetically determined (not diet-responsive), and is elevated in approximately 20% of the population, at levels above 50 mg/dL, it independently doubles to triples early cardiovascular event risk through both atherogenic and thrombogenic mechanisms, making it the most common undiagnosed cardiovascular risk factor in otherwise healthy men with normal LDL, and it should be measured once in every adult's lifetime (Tsimikas et al., JACC, 2020).

Your doctor has not tested it because Lp(a) is not included in the standard lipid panel (which only measures total cholesterol, LDL-C, HDL-C, and triglycerides) and has historically lacked approved pharmacological treatments (which reduced clinical motivation for testing). With RNA-targeted therapies (pelacarsen, olpasiran) in late-stage clinical trials, and niacin showing Lp(a) reduction as one of its few surviving applications, the treatment landscape is changing. The reason to test it now: if you have a family history of premature heart disease and your LDL is normal, Lp(a) may be the explanation. Knowing it changes risk stratification, monitoring intensity, and shared decision-making about statin therapy.

Honesty Scale: Solid (1) for Lp(a) elevation as an independent cardiovascular risk factor. Solid (1) for the one-lifetime testing recommendation.

What to do: Ask your physician for a one-time Lp(a) test at your next appointment. If they are unfamiliar with it, reference the 2020 ACC/AHA Cardiovascular Risk Assessment Guideline (which includes Lp(a) as a risk-enhancing factor). If Lp(a) is above 50 mg/dL (or above 125 nmol/L), this is a clinically meaningful finding that warrants more aggressive cardiovascular risk management.

For the full picture, read The ApoB/Lp(a)/Lipids Deep Dive