The LDL Cholesterol/HDL Cholesterol Ratio is Obsolete

Doctors have been telling their patients for over 30 years that they need to bring their LDL (“bad“) cholesterol levels down and their HDL (“good“) cholesterol levels up. But it turns out that the LDL/HDL ratio isn’t really the best predictor of cardiovascular health.

Cholesterol is a fatty substance that doesn’t dissolve in water. Since the blood is mostly water, the only way the body can transport cholesterol from one tissue to another is by enclosing the cholesterol in a “balloon” made of water-soluble protein.

LDL or low-density lipoprotein is a bigger balloon. HDL or high-density cholesterol is a smaller balloon. Scientists used to think that because a bigger piece of cholesterol was more likely to get stuck in corner or turn of a blood vessel, LDL was more dangerous than HDL. That’s why lowering the LDL/HDL ratio was thought to be a good health objective.

Scientists now know that the size of the cholesterol particle does determine whether it is likely to be involved in making a “clog” in a blood vessel, but not in the way they previously thought. It turns out that bigger, fluffier pieces of LDL cholesterol don’t form plaques, but smaller, denser pieces of LDL cholesterol do. The bigger pieces of LDL cholesterol are attached to a protein known as apo-A, and the smaller pieces of LDL are attached to a protein known as apo-B.

You can have high LDL and low apo-B, and you don’t have an increased risk of heart disease. You can have low LDL and high apo-B, and you do have an increased risk of heart disease. The old tests never predicted heart disease very well.

So why do doctors continue to use tests that don’t really tell whether you are at increased risk for heart disease? In the words of two doctors who help run the National Cholesterol Education Program, “Because it will take time before apolipoprotein terminology is recognized by the general public and recommended by the NCEP Adult Treatment panel toevaluate risk, it may be more efficacious to continue adhering to the already familiar” LDL/HDL ratio.

Doctors who prescribe cholesterol-lowering medicines on the basis of LDL/HDL ratio won’t miss any patients who need the drug, but they will give the drug to some patients who don’t need it. Doctors who prescribe cholesterol-lowering medicines on the basis of the apo-B/apo-A ratio won’t miss any patients who need the drug, but they won’t expose other patients to side effects needlessly.

Should you insist on apo-B/apo-A testing before taking a statin drug. Absolutely! Don’t expose youself to unnecessary side effects. However, once you have started treatment, the more readily available and much less expensive LDL and HDL tests are a good “guestimate” of your progress.