What Is Lipoprotein(a), and Should You Test It?

Lipoprotein(a), or Lp(a), is a particle like LDL with an extra protein attached. A high level raises the risk of heart attack, stroke, and narrowing of the aortic valve, and it’s set mostly by your genes: diet and exercise barely change it. Because it’s stable over life, European guidance recommends measuring it at least once in every adult. About one in five people have a level high enough to raise their risk.

This article is general information, not medical advice.

What the Guidance Says

• European Atherosclerosis Society consensus (Kronenberg and colleagues, 2022). Lp(a) should be measured at least once in every adult. Levels above 50 mg/dL (about 105 nmol/L) increase cardiovascular risk, with risk rising continuously; levels under 30 mg/dL (75 nmol/L) are unlikely to add much. About 20% of people of European descent have levels above 50 mg/dL.
• 2019 ESC/EAS dyslipidaemia guidelines (Mach and colleagues). Measuring Lp(a) at least once in a lifetime is recommended, to identify people with very high levels, above 180 mg/dL (430 nmol/L), whose lifetime risk may match that of inherited high cholesterol.
• 2018 AHA/ACC cholesterol guideline (Grundy and colleagues). An Lp(a) of 50 mg/dL or 125 nmol/L or more is a risk-enhancing factor that can favour starting a statin.

Testing is especially worth considering with a family history of early heart disease or of high Lp(a).

Mass and Molar Units Don’t Convert

Labs report Lp(a) either by mass (mg/dL) or by particle number (nmol/L). The protein that makes Lp(a) varies in size between people, so a particle’s mass varies too, and there’s no exact conversion factor between the units. The EAS consensus prefers nmol/L. Keep to the unit your lab uses, and compare results in the same unit.

What You Can Do About It

Medicines that lower Lp(a) specifically have been in large outcome trials; ask your doctor what’s available now. Meanwhile, with a high Lp(a), guidelines advise managing everything else more intensively: lowering LDL cholesterol and ApoB, blood pressure, and other risk factors. Statins don’t lower Lp(a), and may raise it slightly, but they still lower overall risk.

Following It in Kaizora

Kaizora keeps Lipoprotein(a) Mass Concentration (mg/dL) and Lipoprotein(a) Molar Concentration (nmol/L) as separate metrics on Labs, since they can’t be converted into each other. Log your result in the unit your lab reported, with the laboratory and its printed range. One test is usually enough, so it’s a good one to log with a note of its method.

The Short Version

• Lp(a) is a mostly inherited risk factor; test it at least once, by European guidance.
• Above 50 mg/dL (about 105 to 125 nmol/L) raises cardiovascular risk.
• mg/dL and nmol/L don’t convert exactly; compare results in the same unit.

Sources

• Kronenberg F et al., “Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement,” European Heart Journal 43, no. 39 (2022): 3925–3946. doi:10.1093/eurheartj/ehac361
• Mach F et al., “2019 ESC/EAS guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk,” European Heart Journal 41, no. 1 (2020): 111–188. doi:10.1093/eurheartj/ehz455
• Grundy SM et al., “2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol,” Circulation 139, no. 25 (2019). doi:10.1161/CIR.0000000000000625