When the doctor orders a “lipid panel”, it typically includes values for total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides. These numbers have long been used as benchmarks for treatment recommendations. In the case of cholesterol-lowering medications, the LDL-cholesterol level is one of the factors that helps determine their usage.
High LDL-cholesterol has been linked to atherosclerosis and heart attacks, but the connection is not dependable. In fact, research shows that up to about 50% of all heart attacks happen to people whose LDL cholesterol levels are within the normal to slightly elevated range. What we are now learning is that there is such a thing as a harmless variety of LDL-cholesterol, called Type A, which is larger and less dense than the Type B variety. It is apparently only the small, dense LDL particles (Type B) that become embedded in the arterial walls and oxidize to form plaques that block bloodflow.
Type A particles are normally associated with low triglyceride levels and high HDL-cholesterol. They represent a low risk of heart attack. Hence, it is possible to have elevated total cholesterol and have little danger of having a heart attack.
The same is true of HDL-cholesterol – bigger is better. The larger particles are those that do a better job of “cholesterol scrubbing” arterial walls. In other words, they are better able to grab the LDL particles and “unstick” them for removal from blood vessels.
Particle size predicts heart disease risk much more accurately than the simple cholesterol values in a standard lipid panel. Still, when all risk factors are analyzed together, a standard lipid panel will often lead to the same conclusions for many (probably most) people. The tests that measure particle size are an added expense, and are probably not very useful for many people, but they can help make a decision about treatment in those cases that are more “borderline”.
When I look at my triglyceride and HDL numbers, I think it is unlikely that I have a Type B scenario with LDL particle size. I am probably one of those people whose LDL-cholesterol is borderline high, but the size of particles means it is not a problem. At least I hope that’s what it means! I think I will eventually have this test done, given my genetic background. Particle size is mostly hereditary, however a healthy lifestyle can improve a person’s situation. It always comes back to that!