Why Would My Doctor Order a Lipoprotein(a) Blood Test?

Q: What is Lipoprotein(a), and why is it important?

A: It’s well known that low-density lipoprotein (LDL), or “bad cholesterol,” is a major cause of heart disease. But there’s a lesser-known kind of cholesterol that can play a role in someone’s heart risk, too.

Studies show that having a high level of a protein called Lipoprotein(a), or Lp(a), in your blood is also a risk factor for heart disease and, to a lesser degree, stroke.

It’s estimated that about one in five people in the U.S. has an Lp(a) level that puts them at risk. But the tricky thing is, Lp(a) level isn’t regularly tested in most people. And, even people with a healthy level of LDL cholesterol could have a high Lp(a) level. So many people are walking around with abnormally high Lp(a) but don’t know it.

We suspect that Lp(a) could be a factor in the rise in heart attacks in younger, seemingly healthy adults who do not have high LDL cholesterol.

The other tricky thing is that your Lp(a) level is in large part genetically wired, so things like diet and exercise won’t really change it. There are currently no FDA-approved drugs to lower it, either — though some potential gene-silencing treatments are being developed and tested.

For now, Lp(a) may be used as part of an overall assessment of a person’s risk for heart disease. But strategies for lowering that risk focus on addressing other risk factors, such as high LDL cholesterol, BMI and blood pressure.

— Cardiologist Leslie Cho, MD