DOCTOR'S VIEW ARCHIVE
Topic: Heart Attack Prevention
Dr. Gregory Thomas:
The total cholesterol to HDL cholesterol ratio is a number that is helpful in predicting an individual's risk of developing atherosclerosis. The number is obtained by dividing the total cholesterol value by the value of the HDL cholesterol. (High ratios indicate higher risks of heart attacks, low ratios indicate lower risk).
High total cholesterol and low HDL cholesterol increases the ratio, and is undesirable. Conversely, high HDL cholesterol and low total cholesterol lowers the ratio, and is desirable.
An average ratio would be about 4.5. Ideally we want to be better than average if we can. Thus the best ratio would be 2 or 3, or less than 4.
Another ratio is LDL/HDL. The LDL/HDL ratio is actually a purer ratio than total cholesterol/HDL, because LDL is a measure of "bad' cholesterol and HDL is a measure of "good" cholesterol, whereas the total cholesterol is the sum of HDL, LDL, and the VLDL. Adding up the values for the HDL, LDL and VLDL makes up the total cholesterol measurement.
Even though the total cholesterol/HDL ratio is not as accurate or pure as the LDL/HDL ratio, the former is more commonly obtained because the total cholesterol is easier and cheaper to obtain than the LDL cholesterol level.
It is important to remember that even with a favorable ratio; we have learned that it is still important to try to obtain an LDL of less than 80-100, regardless of the HDL value, especially in the presence of multiple other risk factors for coronary artery disease (genetic predisposition, tobacco use, hypertension, and diabetes). In patients with known coronary artery disease (history of bypass surgery, stents, or PTCA), an LDL of less than 80 is extremely desirable.
Revising Medical Author: Daniel Kulick, MD, FACC, FSCAI
Last Editorial Review: 4/30/2007