You said what most people have learned about LDL and HDL cholesterol is too simplistic to accurately assess their heart health. Would you explain?
JK: Let’s start with LDL cholesterol, the so-called "bad cholesterol." The standard blood test most Americans receive just gives you the raw LDL number, as well as your raw HDL number and overall cholesterol number. But that raw LDL number isn’t enough to ascertain your risk for heart disease. Two people can have the same LDL number, but one may have a much higher risk for a heart attack and the other may not have much risk at all.
The difference in risk largely depends on two other factors that the standard blood test doesn’t measure: the number of LDL particles and their size.
A good analogy is a stretch of highway with 100 passengers. If those passengers are driving 10 to a minivan, then the road isn’t congested—there are only 10 large vehicles on it. But if all 100 passengers are riding in individual cars, you have congestion.
The same thing happens with LDL cholesterol. If you have many LDL particles with only a small amount of cholesterol in each one, that’s of concern, because your arterial highway is very congested. But if you have fewer and more packed particles, your arterial highway might not be congested at all.
This situation typically arises where people have a low LDL number, but it could also occur where someone has a higher LDL number. Let’s say your LDL is 160, and your overall cholesterol number is 240. Without further data, that isn’t looking very good. But if you have a relatively modest number of LDL particles, maybe 1200, the results aren’t so unfavorable. A second person with the same overall cholesterol and same LDL number who has 2500 or 3000 particles has a much higher risk of a heart event.
What LDL particle numbers and sizes are considered desirable, and which are of concern?
JK: So far, only a few large data sets have looked at these more advanced cholesterol panels, but here’s what we know: An LDL particle number close to 1000 is at the lower risk part of the spectrum, and numbers of 2000 — 3000, which routinely arise, point to a much higher risk.
When it comes to particle size, the bigger the better. Small particles are typically sized 19 nm or under. Hard and dense, they’re like small "golf balls" that knock into your arteries to cause plaque. Bigger particles are generally over 21 or 21.5 nm. They tend to be more spongy and much less likely to harden your arteries. And they’re changeable. Lifestyle changes particle size better than anything, though of course medications can do this too.
So, get an advanced cholesterol panel, at least once. These days insurance companies are covering it pretty routinely. Even when they don’t, the cost is way under $100.