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Ongoing advances in epidemiology and clinical research have led to recent revisions of consensus assessment and treatment guidelines for high blood cholesterol and high blood pressure.1,2 |
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In 2001, the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults published a new set of guidelines for management of cholesterol.1 The new guidelines, known as ATP III (Adult Treatment Panel), are based on procedures for risk assessment from which specific target levels for total cholesterol and low-density lipoprotein (LDL or “bad cholesterol”), as well as treatment recommendations, are derived.
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The primary target for treatment, as in the previous guidelines (ATP II), is the reduction of blood levels of LDL. Elevated LDL has been identified as a major cause of coronary artery disease (CAD), and reduction in LDL has been shown in a number of large clinical trials, to reduce the risk of CAD. Treatment recommendations are based on a stepwise assessment of risk, beginning with fasting a lipid analysis.
The classification of levels of LDL, total cholesterol, high-density cholesterol (HDL or “good cholesterol”), and triglycerides based on fasting lipid analysis, are shown below.
ATP III Classification of Fasting LDL, Total Cholesterol, HDL and Triglyceride Levels
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LDL Cholesterol
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< 100 mg/dL
100-129 mg/dL
130-159 mg/dL
160-189 mg/dL
> 190 mg/dL
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Optimal
Near or above optimal
Borderline high
High
Very high
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Total Cholesterol
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< 200 mg/dL
200-239 mg/dL
> 240 mg/dL
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Desirable
Borderline high
High
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HDL Cholesterol
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Triglycerides
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< 150 mg/dL
150-199 mg/dL
200-499 mg/dL
> 500 mg/dL
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Normal
Borderline high
High
Very high
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Because this issue is so important, the National Heart, Lung, and Blood Institute has initiated the “Know Your Cholesterol” program. For more information, click here.
Once the LDL, HDL, total cholesterol and triglycerides levels are determined, the next step is the assessment of other major risk factors for CAD. Risk factors that are considered “major” in ATP III are:
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Cigarette smoking |
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Hypertension (blood pressure > 140/90 mm Hg, or on antihypertensive medication |
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Low HDL cholesterol (< 40 mg/dL) |
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Family history of premature CAD (CAD in male first-degree relative < 55 years old or in female first-degree relative < 65 years old) |
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Age (men > 45 years, women > 55 years) |
For more information on risk factors, click here.
Individuals with 0-1 of the risk factors listed above are at extremely low risk for CAD or CAD events, and no further assessment of risk is necessary (although individuals with 0-1 risk factors and high LDL should be considered for drug therapy).1 For individuals with 2 or more of the risk factors listed above, a more detailed risk assessment is performed using tables derived from analyses of the Framingham Heart Study, a long-term longitudinal study of cardiovascular risk. The Framingham risk score provides a percentage estimate of the likelihood of developing CAD or experiencing a CAD event within the next 10 years.1
Fom the risk estimates derived from risk factors and, if appropriate, from the Framingham information, ATP III then provides the target LDL level, the LDL level at which therapeutic lifestyle changes should be initiated, and the LDL level at which drug therapy should be instituted.1 These are summarized below.
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From the risk estimates derived from risk factors and, if appropriate, from the Framingham information, ATP III then provides the target LDL level, the LDL level at which therapeutic lifestyle changes should be initiated, and the LDL level at which drug therapy should be instituted.1 These are summarized below.
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LDL Target Levels and Treatment Recommendations for
Different Categories of Risk1
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Risk Catagory
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LDL (mg/dL) Goal
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LDL Level (mg/dL) at which to initiate therapeutic lifestyle changes
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LDL Level (mg/dL) at which to initiate drug therapy
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Existing CAD or CAD risk equivalents* (10-year risk > 20%)
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<100
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> 100
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> 130
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2+ Rsk Factors (10-year risk > 20%)
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<130
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<130
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10-year risk
10-20%:> 130
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10-year risk
<10%:> 160
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0-1 Risk Factor
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<160
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<160
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<190 (drug therapy optional for LDL 160-189)
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*CAD risk equivalent carries a > 20% 10-year risk of CAD development or event. Diabetes is considered a CAD risk equivalent, as is any combination of risk factors that confer > 20% 10-year risk using the Framingham Heart Study data. For more information, click here.
Therapeutic lifestyle changes include:1
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Dietary control (reduction of saturated fat to < 7% of total calories, cholesterol to < 200 mg/day) |
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Intake of plant stanols/sterols (2 g/day) and increase soluble fiber intake (10-25 g/day) |
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Weight reduction |
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Increased physical activity |
Pharmaceutical options for lowering LDL cholesterol include:1
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Statins |
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Bile acid sequestrants |
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Nicotinic acid |
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Fibric acids |
For more information on these and other therapies, click here.
The full ATP III report summarizes the expected outcomes from these interventions, as well as clinical trial evidence, side effects, and contraindications for the various drug therapy options.
ATP III also added a secondary target for therapy: the “metabolic syndrome,” a group of risk factors based on overall metabolism. Metabolic syndrome has been found to strongly increase the risk of CAD at all levels of LDL. A diagnosis of metabolic syndrome is based on the presence of at least three of the following factors:1
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Abdominal obesity (waist circumference > 40 inches in men, > 35 inches in women) |
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High triglyceride level (> 150 mg/dL) |
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Low HDL level (< 40 mg/dL in men, < 50 mg/dL in women) |
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High blood pressure (> 130/ > 85 mm Hg) |
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Elevated fasting glucose (> 110 mg/dL) |
Patients with metabolic syndrome should be treated with a combined program of weight control and increased physical activity.
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| References |
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