The Nation's Health

Lipids: More on the “Rule of 60”

Despite its apparent simplicity, there’s a lot of thought and wisdom in the Rule of 60.

What if you achieve only a single value in the Track Your Plaque “Rule of 60”? What if, for instance, you got LDL down to 60 mg/dl, but ignored the fact that your HDL was 41 mg/dl and triglycerides were up to 145 mg/dl? Can you still do pretty well?

Probably not. In fact, this specific combination of low HDL and high triglycerides tells me several things:

1) LDL is really much higher than suggested by the 60 mg/dl, which is a calculated value, often much higher. Recall that calculated LDL is prone to immense inaccuracy. When measured, the LDL is commonly somewhere between 120 and 160 mg/dl. However, when you raise HDL to 60 and reduce triglycerides to 60, much of the inaccuracy is removed, i.e., calculated LDL becomes more accurate. LDL can be measured as LDL particle number (NMR), apoprotein B, or direct LDL.

2) LDL particles are small. This is yet another reason why the weight-based LDL measures can be inaccurate. Imagine you have two identical glass jars full of marbles. One jar has small marbles, the other has large marbles, but both jars have the same weight in marbles. Which jar has more marbles? The one with small marbles, of course. The same phenomenon occurs with LDL particles: at the same weight, you can have different numbers of LDL particles. It’s the number of particles that better determine risk for heart disease, not the weight.

3) Triglycerides of 145 mg/dl is actually below the target advised by the National Cholesterol Education Panel Adult Treatment Panel-III guidelines, i.e., you’re okay by conventional standard. But look beneath the surface, and you’ll find that triglycerides at 145 mg/dl are associated with flagrant excesses of VLDL lipoprotein particles and a greater likelihood of a postprandial (after-eating) disorder (increased IDL or postprandial triglycerides), both of which add to coronary plaque.

4) This pattern is also commonly associated with higher blood sugar, higher blood pressure, increased inflammation (e.g., C-reactive protein), increased fibrinogen—all the facets of the metabolic syndrome, or pre-diabetes.

In fact, some of the most aggressive plaque growth—increasing heart scan scores—will occur with this specific pattern. So just achieving one facet of the Track Your Plaque Rule of 60 does not suffice. It’s the whole package that really stacks the odds in your favor of stopping or dropping your heart scan score.