What is Lipoprotein(a)?
Lp(a) is the shorthand for Lipoprotein(a). When it’s spoken, you’ll hear it referred to as “L-P- little-A.”
It’s a very complex lipoprotein that appears to increase the risk for both heart disease and stroke. Lp(a) looks like LDL cholesterol with some key differences. LDL has a single apolipoprotein B attached on its surface. Lp(a), however, has an apolipoprotein B attached on its surface, and that apolipoprotein B has an apolipoprotein (a) attached to it. Lp(a) also contains oxidized phospholipids (OxPL).
Each of these components come together and results in a lipoprotein than can cause artery blockages, artery clogging, and inflammation.
Lipoprotein(a) and Artery Blocking
LDL is a component of Lp(a), so Lp(a) has a lot in common with LDL. This means that Lp(a) can enter the artery wall and cause plaque buildup. Too much plaque buildup leads to atherosclerosis, and atherosclerosis increases the risk of heart attack and stroke.
Lipoprotein(a) and Artery Clogging
The apolipoprotein(a) part of Lipoprotein(a) looks like something called plasminogen. Plasminogen is an important protein we all have in our blood that protects us from uncontrolled clotting. While apolipoprotein(a) looks like plasminogen, it doesn’t act like plasminogen. It may actually compete with plasminogen. When apolipoprotein(a) binds to a clot, it can’t break it up. This is why it’s believed that elevated Lp(a) favors clotting.
When plaque has formed and there’s a clot in an artery, it can spell trouble. If plaque ruptures and a blood clot forms on top of the ruptured plaque, it can completely block the flow of blood. In the case of a heart artery, this is how a heart attack happens.
Lipoprotein(a) and Inflammation
We all have OxPLs in our cell membranes, and they promote inflammation. This is a problem for many reasons including increasing the risk of plaque rupture.
When it comes to Lp(a), the OxPL portion plays a role in the start of atherosclerosis and aortic valve stenosis.
OxPL also appears to be “pro-osteogenic” in the aortic valve. This literally means “producing bone.” Essentially, the OxPLs deposits calcium in the valve. While you want calcium in your bones, you don’t want it in your aortic valve. A calcified valve is stiff, doesn’t open completely, and reduces blood flow.
What causes high Lipoprotein(a)?
High Lipoprotein(a) is genetically inherited and is not related to your diet or exercise. If you have an elevated Lp(a), it’s likely that at least one of your parents has a high Lp(a). This is important to know as you’ll also want to have your children tested. Each time you have a child you have a 50% chance of passing on the gene for high Lp(a). Learn more about high Lipoprotein(a) here.