You’ve probably had a standard lipid panel at a routine physical, since it’s generally recommended every four to six years for healthy adults, and more often for those with heart disease or diabetes. The blood test checks your levels of total cholesterol, low-density lipoprotein or LDL (the “bad” cholesterol that can form plaque on artery walls), high-density lipoprotein or HDL (the “good” cholesterol that helps funnel extra fats to the liver for removal) and triglycerides (a common type of fat that, coupled with high LDL, can threaten heart health).
What it doesn’t check, however, is your level of lipoprotein(a), or Lp(a), a “specific type of cholesterol particle that circulates in the bloodstream and acts as a major independent risk factor for cardiovascular disease,” said Ryan Smith, a cardiologist at Orlando Health Heart and Vascular Institute. About 1 in 5 people have a high blood level of Lp(a), and, as with high levels of other types of cholesterol, it doesn’t cause any symptoms — until it triggers the kind of blockage in a blood vessel that brings on a heart attack or stroke.
In March, a group of medical organizations — including the American Heart Association (AHA) — released new guidelines for cholesterol management and recommended for the first time that every adult be tested for Lp(a) once in their lifetime. Your primary care physician can order this specific blood test as an addition to a standard lipid profile or other routine bloodwork, and it’s now largely covered by major insurance plans.
An Lp(a) test hadn’t previously been included in cholesterol guidance because it wasn’t clear what you should or could do about a high level, said Jeffrey Berger, director of the Center for the Prevention of Cardiovascular Disease at NYU Langone Heart. We still don’t know if lowering Lp(a) can decrease cardiovascular risk (though Berger said research and drug trials increasingly hint at this benefit). And because Lp(a) level is largely driven by genetics, it doesn’t shift in response to lifestyle changes the way other cholesterol levels do.
But as an “accumulation of data has demonstrated again and again” how a high Lp(a) can ramp up the likelihood of a cardiac event, Berger said, it’s become clear that people should know if they have this genetic risk factor — so they can more aggressively tackle the modifiable ones.
Why lipoprotein(a) poses a unique cardiovascular risk
An Lp(a) level above 125 nanomoles per liter (sometimes measured as 50 milligrams per deciliter, or mg/dL), has been shown to raise your risk of heart disease and stroke — and at 250 nanomoles per liter (100 mg/dL), risk may double.
Like an excess of “bad” LDL cholesterol, extra Lp(a) can pile up in the arteries, causing atherosclerosis, where plaque narrows the vessels and hinders blood flow to key organs. Because Lp(a) has an additional protein tail, called apolipoprotein A, it’s even stickier and more likely to form fatty plaques than LDL, Smith said. The resulting reduction in blood flow can cause a stroke or a heart attack.
At the same time, Lp(a) can interfere with a part of the clot-breakdown process, which could make you more prone to blood clots. And it carries certain pro-inflammatory molecules, which can, over time, harm the aortic valve and contribute to hardening of the arteries, Smith said.
Who is most likely to have a high Lp(a) level
Because Lp(a) level is almost entirely genetic, certain groups may be more at risk, particularly people of African or South Asian descent, followed by White people, Hispanic people and people of East Asian descent. The AHA also especially urges testing in anyone with a known family history of high Lp(a) as well as those with a personal or family history of early cardiovascular disease (considered underage 55 in men and under 65 for women) and people with familial hypercholesterolemia (FH), an inherited condition causing high LDL levels.
In most people, a single Lp(a) test is enough to gauge risk, as it doesn’t typically change, Smith said. A few exceptions: People with thyroid disorders, a kidney condition called nephrotic syndrome, or certain other acute inflammatory conditions, as well as those pregnant and those in menopause, might see elevated Lp(a) levels, Smith said. But when these scenarios resolve or are treated, Lp(a) generally returns to its genetic baseline, he said.
How to protect your heart if you have a high Lp(a) level
Since there are no interventions that meaningfully lower Lp(a), it’s recommended that those with high Lp(a) carefully manage other risk factors for heart disease, like blood sugar and blood pressure, and focus on keeping LDL cholesterol levels low, Berger said, to reduce overall risk. Research suggests it’s possible to offset the extra risk of a high Lp(a) by decreasing LDL by an additional 20 mg/dL, or more, below the general 100 mg/dL target for healthy adults.
That might start with brushing up on cholesterol-lowering lifestyle behaviors: The AHA suggests doing at least 150 minutes of moderate-intensity physical activity weekly, eating a plant-laden diet, quitting smoking, hitting or maintaining a healthy weight and getting seven to nine hours of sleep nightly. People with high Lp(a) are also often prescribed statins, Smith said, to more intensely target LDL levels and reduce cardiovascular risk in the process.
Some doctors may alternatively prescribe a non-statin cholesterol medication called ezetimibe, which blocks the absorption of cholesterol in the small intestine and could slightly reduce Lp(a), Smith said. Others might recommend a PCSK-9 inhibitor, which is a type of drug that helps the liver remove LDL cholesterol from the blood and may also have a modest impact on Lp(a), he added. (A newly FDA-approved oral PCSK-9 inhibitor has similar efficacy as the two injectable PCSK-9 inhibitors currently on the market.)
Soon, there may be drugs available that explicitly lower Lp(a). A new class of medications in late-stage clinical trials targets the RNA (a molecule in cells that plays an essential role in facilitating chemical reactions and making proteins) responsible for producing the lipoprotein, Smith said. Preliminary data suggests these medications can lower Lp(a) levels, but it’s still to be determined if they ultimately reduce risk for poor cardiac outcomes.
In the meantime, Smith said, you can think of Lp(a) as one risk factor that should be considered in a broader conversation with your doctor about your overall cardiovascular risk. The sooner you broach the topic, the better the chance that you can be proactive and avoid a heart attack or stroke down the line, he said: “Prevention is really supreme in our field.”
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