Cholesterol: What Do The Numbers Mean For Cardiovascular Health?

LEXINGTON, Ky. (Oct. 26, 2011) - The following column appeared in the Lexington Herald-Leader on Sunday, October 23.

Cholesterol: What do the numbers mean for cardiovascular health?

Cholesterol, though essential to the human body, can be detrimental in excess. Knowing your cholesterol numbers and taking action to maintain them at a healthy level is one practical thing everyone can do to maintain good cardiovascular health.

Cholesterol is a fat present in the blood. Measurements of the amount and type of cholesterol present in the body, determined by a simple blood test, can tell a person a lot about their risk for cardiovascular disease.

There are two types of cholesterol: low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Although LDL is known as the "bad" cholesterol, it is necessary for the human body to have some LDL for normal function of cells.

Too much LDL, however, can signal an elevated risk for cardiovascular illness. HDL removes excess cholesterol from cells, such as those on the inner surfaces of arteries, and takes it back to the liver where it is metabolized. HDL also has anti-inflammatory and anti-clotting effects.

So, what are the optimal numbers for cholesterol? Ideally, a healthy adult should have an LDL less than 70 milligrams per deciliter (mg/dl), and a total cholesterol number of 120-130 mg/dl.  This total cholesterol includes the LDL, HDL and very low-density lipoproteins (VLDL). These numbers represent the ideal cholesterol measurement for a healthy person who has fasted before a blood test.

Because HDL can have heart-protective effects at high levels, some physicians also consider the ratio of total cholesterol to HDL. Ideally, this ratio should be under 3.5. A higher HDL count can lower this ratio. In my practice, I focus more on lowering unhealthy LDL numbers.

Because cardiovascular disease and high cholesterol can be hereditary, if there is a strong family history of heart disease then cholesterol should be checked in children by age 5. (Interestingly, future cholesterol levels can often be predicted via cord blood cholesterol in newborns: If it is over 50 mg/dl, it may herald future problems with cholesterol.)

Regardless of family history, everyone should have a baseline cholesterol test by the time they are 21. From that point on, cholesterol should be checked every couple of years until age 40 and yearly thereafter.

Although heredity may contribute to high cholesterol, most people can lower their cholesterol through lifestyle changes and with medication if necessary. Eating a diet low in saturated fats and cholesterol, obtaining and maintaining a healthy weight through caloric monitoring, and healthy exercise can all contribute to lowering LDL levels.

If, after lifestyle modifications are implemented, a person is unable to reduce their LDL below 100 mg/dl (or 70 mg/dl for diabetics or people at elevated risk of cardiovascular disease), it is often time to consider medication. Medication is not a solution by itself. It must be implemented along with a healthy diet and exercise routine.

Understanding cholesterol is an important key in maintaining good cardiovascular health. Talk with your doctor, and understand the contributing factors maintaining your heart's health.

Dr. Thomas Whayne is a professor of medicine at the University of Kentucky College of Medicine and a cardiologist for UK HealthCare.