ProLipid

Target Cholesterol Levels: It All Depends On Your Risk Category

Persons with an elevated heart attack risk should lower their LDL ("bad") cholesterol. The National Cholesterol Education Program defines three "Risk Categories" with different LDL cholesterol targets for each:

Risk factors include:

• Cigarette smoking
• Hypertension (blood pressure over 140/90)
• Low HDL or "good" cholesterol (< 40 mg/dL)
• Family history of premature coronary heart disease (CHD): CHD in male first-degree relative younger than 55 or in a female first-degree relative younger than 65
• Advanced age (Men 45 years and older & women 55 years and older)

To determine your number of risk factors, count the above items that apply to you. You can subtract one from your count if you have a HDL ("good") cholesterol level higher than 60 mg/dL. HDL cholesterol above 60 mg/dL is called a "negative" risk factor because it is positive for the health of the coronary arteries.

You can easily calculate your individual LDL cholesterol target, your risk category and your 10-year risk of a heart attack using our risk calculator.

The Cholesterol Risk Ratio

Since both high LDL cholesterol (or high total cholesterol) and low HDL cholesterol influence coronary artery disease, combining both factors to one number is helpful. LDL cholesterol or total cholesterol are divided by HDL cholesterol, resulting in the cholesterol ratio or cholesterol risk ratio for predicting coronary heart disease.

Although the total cholesterol/HDL cholesterol ratio is not as accurate or pure as the LDL/HDL ratio, the former is more commonly obtained because total cholesterol is easier and cheaper to measure than LDL cholesterol levels.

Risk Ratios (total cholesterol/HDL cholesterol):

• Optimal: lower than 3.5
• Average: approximately 4.5
• Increased: higher than 5.0

Example 1: Anyone with a "borderline high" total cholesterol of 230 mg/dL and an "average to low" HDL value of 45 mg/dL has a risk ratio of 5.1 or an increased risk.

Example 2: Anyone with a high total cholesterol of 270 mg/dL and a high HDL level of 70 mg/dL has a risk ratio of approximately 3.9 or a lower than average risk.

Use of the risk ratio may predict coronary artery disease more accurately than with total cholesterol levels alone.

Influence of Cholesterol Risk Ratio on Heart Disease

Reports from the Framingham Heart Study suggest the following influence of total cholesterol to HDL cholesterol ratios on male heart disease risk:

• Half the average heart disease risk at a ratio of 3.4
• Average heart disease risk at a ratio of 5.9
• Double the average heart disease risk at a ratio of 9.6

Because women usually have higher HDL levels, the total cholesterol to HDL cholesterol ratio is different:

• Half the average heart disease risk at a ratio of 3.3
• Average heart disease risk at a ratio of 4.4
• Double the average heart disease risk at a ratio of 7.0

For an even more precise measurement of coronary heart disease risk, please use our risk calculator and take into account additional factors such as gender, age, smoking, blood pressure levels and diabetes.