Cholesterol has long been a numbers game. Today, though, the numbers considered most important — that best indicate your risk for heart disease — may not be the four typically revealed by a cholesterol-checking blood test, called a lipoprotein profile. Instead, two other numbers have become key.
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The National Heart, Lung, and Blood Institute explains that your cholesterol blood test results will indicate your level for high-density lipoprotein (HDL) cholesterol, considered the good cholesterol; low-density lipoprotein (LDL) cholesterol, the bad type; triglycerides, a type of fat in your blood; and total cholesterol, a combination of all three.
Now, though, medical experts believe that two other numbers give a better indication of your future heart health: your non-HDL cholesterol and what's known as your cholesterol ratio.
New Take on Cholesterol Numbers
Your LDL, HDL and triglyceride levels are used to develop the cholesterol ratio and the non-HDL level, and both of those may be more important for risk determination than total cholesterol, according to the Mayo Clinic.
To get your cholesterol ratio, you simply divide the number representing your total cholesterol by your HDL cholesterol number. "A number less than 2.5 may suggest increased cardiovascular disease risk," explains Luke Laffin, MD, a cardiologist in the preventive cardiology and rehabilitation section at the Cleveland Clinic's Heart and Vascular Institute.
Non-HDL cholesterol may be even more important than the cholesterol ratio, the Mayo Clinic says. This number is also a simple calculation: Subtract your good HDL cholesterol from your total cholesterol. "Because this number only reflects bad cholesterol and triglycerides, it is a better predictor of risk," says Dr. Laffin. "A good number would be less than 130."
Your total cholesterol number, once the number that people tended to focus on, is no longer considered the key number, Dr. Laffin says. In fact, he says, today it would not be the basis for determining whether you need a cholesterol-lowering medication.
Determining Your Risk
The risk that's linked to your cholesterol numbers is known as your cardiovascular risk — the chance that you'll have a heart attack or stroke. Too much cholesterol in your blood can cause a substance, known as plaque, to build up on the inner walls of your blood vessels, restricting and possibly blocking blood flow to your heart and other organs.
However, rather than use any single cholesterol number to determine your specific cardiovascular risk, Dr. Laffin says, your doctor now would plug numbers from your blood test into a 10-year risk calculator, developed jointly in 2013 by the American Heart Association (AHA) and the American College of Cardiology (ACC) and published in the journal Circulation in November 2013.
Also entered into the risk estimator, according to the ACC, would be such data as your age, sex and race, your blood pressure and any blood pressure medications you take, whether you have diabetes and whether you have taken statins or low-dose aspirin. The lastest update of the ACC/AHA guidelines appears in the September 2019 issue of Circulation.
Read more: 7-Day Low-Cholesterol Diet Menu
Once You Know Your Risk
Once the risk calculator has determined your risk — how likely it is that you will have a heart attack or stroke in the next 10 years — your doctor can decide whether treatment is needed and, if so, together you can develop a treatment plan, Dr. Laffin says.
If you do need treatment, the medication prescribed will usually be a statin drug. According to the American Heart Association (AHA), statins are a first-line treatment that directly reduce the risk for heart attack or stroke from bad cholesterol.
What About Specific Numbers?
Even with the new emphasis on the risk calculator, the numbers you've become familiar with over the years should not be ignored. For instance, the AHA says you should start a conversation with your doctor if your LDL is over 190.
"Your LDL, the bad cholesterol number, is the most important number for deciding if you need treatment," says Dr. Laffin. "If that number is over 190, you probably will need treatment. If it is less than that, treatment will depend on a combination of your risk factors for heart attack or stroke combined with your LDL.".
As for triglycerides, they're not cholesterol but they, too, can increase your risk for heart disease. As the Mayo Clinic explains, your body converts calories you don't use into these fats. A triglyceride number over 200 is considered high, and over 500 is very high. If your triglyceride number does not come down with lifestyle changes, you may need medication.
"This number has become more important recently because we have a new medication to treat high triglyceride," says Dr. Laffin. "Before this, medications were less effective. The new medication is a purified type of fish oil."
Bottom Line on Cholesterol Risks
According to the AHA, no cholesterol numbers mean much without including all factors that affect your risk for a future heart attack or stroke. Medical experts now know that it's not as simple as a total cholesterol score.
So, get tested, talk to your doctor and come up with an individualized plan to lower your cardiovascular risk.
Is This an Emergency?
- National Heart, Lung, and Blood Institute: “High Blood Cholesterol - What You Need to Know”
- American Heart Association: “What Your Cholesterol Levels Mean”
- Luke Laffin, MD, cardiologist, Preventive Cardiology & Rehabilitation, Heart & Vascular Institute, Cleveland Clinic Main Campus
- Mayo Clinic: “Cholesterol Ratio or Non-HDL Cholesterol: Which Is Most Important?”
- American Heart Association: “Cholesterol Medications”
- Mayo Clinic: “Triglycerides: Why Do They Matter?”
- Circulation: "2013 ACC/AHA Guideline on the Assessment of Cardiovascular Risk"
- American College of Cardiology: “ASCVD Risk Estimator Plus”
- Circulation: "2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines"