According to the Centers for Disease Control, 631,636 people died of heart disease in 2006, or 26 percent of total deaths in the United States. One of the markers for a risk of heart disease is a high cholesterol reading, based on total cholesterol levels and the cholesterol components, LDL and HDL. But equally important is the ratio of cholesterol components to each other; improving that ratio could also mean decreasing your odds for a heart attack or stroke.
Identification
Cholesterol is a waxy substance in your body that is necessary for good health. Your liver and other cells manufacture 75 percent of blood cholesterol, and the other 25 percent comes from your diet. HDL, which stands for high-density lipoprotein, is the "good" form of cholesterol that helps prevent the "bad" LDL -- low-density lipoprotein -- cholesterol from clinging to the walls of your arteries.
Ratios
While it's important to keep your good HDL cholesterol levels high and your bad LDL cholesterol levels low, your cholesterol ratios are also important, with the smaller the number, the better, according to the American Heart Association. If your total cholesterol is 200 and your HDL is 60, that would equal a ratio of 3.3, or 200 divided by 60. If your HDL is 35, then your total cholesterol-to-HDL ratio would be higher, at 5.7. From the long-term Framingham Health Study in Massachusetts, it was determined that for men, a total cholesterol-to-HDL ratio of 5 means an average risk for heart disease; 3.4, about half the average risk; and 9.6, double the average risk. Women have higher HDL levels in general, so a ratio of 4.4 would signify an average risk; 3.3 is half the average; and 7, double the risk. Even if your total cholesterol level is high, having a low total-to-HDL ratio could mean your risk of heart disease is also lower.
Considerations
Certain factors can skew your cholesterol results. If you have high levels of blood triglycerides, you may also have a lower HDL cholesterol level and a higher risk of heart attack and stroke. Progesterone, anabolic steroids and male sex hormones such as testosterone can also lower HDL cholesterol levels, while female sex hormones found in birth control pills may raise HDL cholesterol levels. Other factors that alter cholesterol levels are stress, infection, injuries, and cancer.
Expert Insight
The Quebec Cardiovascular Study at the Quebec Heart Institute in 2001 studied ratios of total cholesterol to HDL, total cholesterol to LDL, and HDL to LDL in 2,100 middle-aged men. The researchers found that the total cholesterol to HDL ratio was most effective in predicting cases of the insulin resistance and metabolic syndromes as well as the risks of ischemic heart disease, with which they're often related. However, a review at the Department of Nutritional Sciences, University of Connecticut, and published in 2008 in the "Journal of the American College of Nutrition," showed that the LDL/HDL ratio is also a valuable and standard tool to evaluate the risk of cardiovascular disease in all populations.
Prevention/Solution
One of the best ways to lower your total cholesterol and LDL cholesterol levels, as well as improving your HDL cholesterol and cholesterol ratios, is to lose weight and exercise at least 30 minutes day. It's particularly helpful if you have a large waist measurement, more than 40 inches if you're a man and 35-plus inches if you're a woman. Other lifestyle measures that can help are to quit smoking, and eat less fat and more soluble fiber of the type found in oats, beans, fruits and vegetables. If lifestyle changes don't bring your cholesterol numbers to acceptable levels, then your doctor may prescribe medications such as statins. The Mayo Clinic recommends that you have a baseline cholesterol test at age 20 with follow-up tests at least once every five years.
