Subclass of LDL cholesterol may predict heart disease

In the journals

High levels of low-density lipoprotein (LDL), or "bad" cholesterol, have long been associated with a greater risk of heart disease. Yet, research has shown that about 75% of heart attack sufferers do not have dangerously high LDL levels.

A study published Nov. 18, 2019, in the International Journal of Nanomedicine looked closer at this issue. Researchers found that high amounts of a subclass of LDL may be a stronger predictor of potential heart problems than overall LDL levels.

LDL consists of three subclasses — A, B, and I. The study found that having LDL made up of 60% A and 20% each of I and B was associated with the least damage to blood vessels, while having a high proportion of B compared with the other two subclasses was associated with the most damage.

The usual calculation of LDL cholesterol levels, which doesn't break down the total by subclass, can underestimate the danger of certain LDL measurements, according to the researchers. For instance, someone with a normal LDL level still could have a high proportion of subclass B and therefore have a higher risk for heart disease than expected. More research will be needed to determine whether measuring LDL subclasses improves assessment of heart risk beyond what doctors do now.

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