The Most Important Thing You Don’t Know About Cholesterol

Heart disease is the leading killer in the United States, and the rest of the world is catching up quickly. This killer can be stopped if caught early enough. Heart disease, and specifically coronary artery disease, is certainly influenced by our environment- whether we smoke, what we eat, how much we exercise. But there is also a significant amount of risk that we cannot control- the risk we are born with.

LDL bad, HDL good?

It is common knowledge that cholesterol is relevant to heart disease. Many people understand that there is “good” cholesterol (HDL) and “bad” cholesterol (LDL). LDL cholesterol turns “red” on your lab report at about 130 mg/dL, but many cardiologists would agree that risk probably starts below that level. All the same, LDL cholesterol (and to a lesser degree HDL-cholesterol) are modifiable with lifestyle changes and medications.

But theres more too it than that. LDL is by far the more important marker of the two. A high HDL in the face of high LDL offers little comfort. Furthermore, LDL does not necessarily reflect all the plaque causing molecules in your blood. That information is perhaps most accurately conveyed but apolipoprotein B (apoB), which does not show up on the standard lipid profile.

Lp(a): The silent killer no one is talking about

There is a group of patients who have normal LDL-C levels but still come in with heart attacks. In fact, some patients do all the “right things” with diet, exercise, statins to control their LDL etc, and still have another heart attack. Many of these patients have an elevated Lipoprotein (a) (also known as Lp(a)).

Lipoprotein (a) has only begun to enter the consciousness of clinicians, despite having been heavily studied for years. Biochemically, Lipoprotein (a) refers to a specific molecular signature that is attached to a cholesterol carrier circulating in our blood. What makes this lipoprotein so dangerous is its supercharged ability to damage blood vessel walls and lead to plaque build up. High levels of lipoprotein (a) are associated with more plaque and heart disease even in people with normal LDL-C levels. Even more alarming is that it is elevated above the normal level (30mg/dL) in one out of five people. Risk appears to accrue in a linear fashion, however, and therefore someone with a level of 31 mg/dL is a relatively lower increased risk than someone with Lp(a) of 100 mg/dL

The amount of Lp(a) you have appears to be determined in large part by your genetics which is why many families with a strong history of heart attacks often have elevated levels of Lp(a). The level is essentially the same in any individual from adolescence through adulthood and therefore checking it once rather than every year is sufficient.

What can you do?

The first step is fairly simple- get your lipoprotein (a) level checked with a simple blood draw. For less than about 150$ once in your life, its unlikely that you will find a more cost effective test that helps prevent disease (with the possible exception of a coronary artery calcium score, more on that later). For now, treatment likely involves simply getting your LDL lower by any means necessary. In the near future there will very likely be medicines that target Lp(a) directly.

Eat good food, exercise regularly and speak with your doctor for personalized advice.