LDL Calculation
LDL calculation from total cholesterol, HDL and triglycerides.
Jennifer Glen
Provided by
EVAL FoundationInstructions
- Triglycerides should only be calculated when fasting.
- The Friedewald formula is known to be inaccurate at extremely high triglyceride (>400 mg/dL) and total cholesterol levels. A direct LDL level should be measured if there is any question about accuracy.
Min 0 – Max 1000
Usage
The Friedewald formula allows clinicians to estimate LDL based on total serum cholesterol, HDL and triglyceride levels. However, this formula is known to be inaccurate at extremely high triglyceride (> 400 mg/dL) and total cholesterol levels (Cordova, 2004). Additionally, triglycerides should only be calculated when fasting.
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Summary
The Friedewald Formula provides an estimation of LDL cholesterol which can serve as a proxy for direct measure of serum cholesterol. A direct level of serum LDL should be measured if there is any question about accuracy.
LDL cholesterol = total cholesterol - HDL - (triglycerides / 5)
Classification of calculated LDL level according to the ATP III guidelines.
LDL Level (mg/dL) | Classification |
<100 | Optimal |
100-129 | Near optimal/above optimal |
130-159 | Borderline high |
160-189 | High |
≥ 190 | Very high |
Classification of triglyceride level according to the ATP III guidelines.
Triglyceride Level (mg/dL) | Classification |
< 150 | Normal |
150-199 | Borderline high |
200-499 | High |
≥ 500 | Very high |
Classification of HDL level according to the ATP III guidelines.
HDL Level (mg/dL) | Classification |
< 40 | Low |
≥ 60 | High* |
*HDL ≥60 mg/dL counts as a "negative" risk factor; its presence removed one risk factor from the total count.
Classification of total cholesterol level according to the ATP III guidelines.
Total Cholesterol Level (mg/dL) | Classification |
< 200 | Desirable |
200-239 | Borderline high |
≥ 240 | High |
Management Considerations
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
Identify presence of clinical atherosclerotic disease and major risk factors.
Determine risk category.
Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
Consider adding drug therapy if LDL exceeds levels based on risk category.
Identify metabolic syndrome and treat, if present, after 3 months of TLC.
Treat elevated triglycerides.
LDL targets (mg/dL)*
"Very" high risk. | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
High risk. | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
Moderate risk. | <130 | > 1 risk factor^ |
Lower risk. | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
Diabetes
Cigarette smoking
HTN (BP ≥ 140/90 or on antihypertensive medication)
Low HDL cholesterol (<40 mg/dL)
Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
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All questions & possible results
GuidanceTitle not visible
Total cholesterol
A number between 0 and 1000, in mg/dL or mm/L.
HDL cholesterol
A number between 0 and 500, in mg/dL or mmol/L.
Triglycerides
A number between 0 and 5000, in mg/dL or mmol/L.
Possible results
LDL Level: Optimal (<100)
Classification of calculated LDL level according to the ATP III guidelines.
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
- Identify presence of clinical atherosclerotic disease and major risk factors.
- Determine risk category.
- Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
- Consider adding drug therapy if LDL exceeds levels based on risk category.
- Identify metabolic syndrome and treat, if present, after 3 months of TLC.
- Treat elevated triglycerides.
LDL targets (mg/dL)*
| "Very" high risk | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
| High risk | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
| Moderate risk | <130 | > 1 risk factor^ |
| Lower risk | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
- Diabetes
- Cigarette smoking
- HTN (BP ≥ 140/90 or on antihypertensive medication)
- Low HDL cholesterol (<40 mg/dL)
- Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
Total Cholesterol Level: High (≥240)
Classification of total cholesterol level according to the ATP III guidelines.
Triglyceride Level: Very high (≥500)
Classification of triglyceride level according to the ATP III guidelines.
Triglyceride Level: Normal (<150)
Classification of triglyceride level according to the ATP III guidelines.
Total Cholesterol Level: Borderline high (200-239)
Classification of total cholesterol level according to the ATP III guidelines.
LDL Level: Borderline high (130-159)
Classification of calculated LDL level according to the ATP III guidelines.
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
- Identify presence of clinical atherosclerotic disease and major risk factors.
- Determine risk category.
- Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
- Consider adding drug therapy if LDL exceeds levels based ib risk category.
- Identify metabolic syndrome and treat, if present, after 3 months of TLC.
- Treat elevated triglycerides.
LDL targets (mg/dL)*
| "Very" high risk | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
| High risk | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
| Moderate risk | <130 | > 1 risk factor^ |
| Lower risk | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
- Diabetes
- Cigarette smoking
- HTN (BP ≥ 140/90 or on antihypertensive medication)
- Low HDL cholesterol (<40 mg/dL)
- Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
Triglyceride Level: High (200-499)
Classification of triglyceride level according to the ATP III guidelines.
LDL Level: Near optimal/above optimal (100-129)
Classification of calculated LDL level according to the ATP III guidelines.
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
- Identify presence of clinical atherosclerotic disease and major risk factors.
- Determine risk category.
- Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
- Consider adding drug therapy if LDL exceeds levels based ib risk category.
- Identify metabolic syndrome and treat, if present, after 3 months of TLC.
- Treat elevated triglycerides.
LDL targets (mg/dL)*
| "Very" high risk | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
| High risk | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
| Moderate risk | <130 | > 1 risk factor^ |
| Lower risk | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
- Diabetes
- Cigarette smoking
- HTN (BP ≥ 140/90 or on antihypertensive medication)
- Low HDL cholesterol (<40 mg/dL)
- Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
LDL Level: High (160-189)
Classification of calculated LDL level according to the ATP III guidelines.
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
- Identify presence of clinical atherosclerotic disease and major risk factors.
- Determine risk category.
- Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
- Consider adding drug therapy if LDL exceeds levels based ib risk category.
- Identify metabolic syndrome and treat, if present, after 3 months of TLC.
- Treat elevated triglycerides.
LDL targets (mg/dL)*
| "Very" high risk | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
| High risk | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
| Moderate risk | <130 | > 1 risk factor^ |
| Lower risk | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
- Diabetes
- Cigarette smoking
- HTN (BP ≥ 140/90 or on antihypertensive medication)
- Low HDL cholesterol (<40 mg/dL)
- Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
HDL Level: Low (<40)
Classification of HDL level according to the ATP III guidelines.
LDL Level: Very high (≥ 190)
Classification of calculated LDL level according to the ATP III guidelines.
The ATP III cholesterol guidelines suggests additional steps after determining lipoprotein levels.
Identify presence of clinical atherosclerotic disease and major risk factors.
Determine risk category.
Initiate therapeutic lifestyle changes (TLC) if LDL is above goal.
Consider adding drug therapy if LDL exceeds levels based ib risk category.
Identify metabolic syndrome and treat, if present, after 3 months of TLC.
Treat elevated triglycerides.
LDL targets (mg/dL)*
"Very" high risk | < 70 | Data may suggest there is little incremental benefit to this extreme, and high associated cost. |
High risk | < 100 | Known CAD or other atherosclerotic disease, diabetes, etc. |
Moderate risk | <130 | > 1 risk factor^ |
Lower risk | <160 | 0-1 risk factors |
*From NCEP 2004 Guidelines
^Risk Factors include:
Diabetes
Cigarette smoking
HTN (BP ≥ 140/90 or on antihypertensive medication)
Low HDL cholesterol (<40 mg/dL)
Family history of premature CAD (CAD in male first-degree relative, or father < 55 years, or female first-degree relative or mother <65 years)
Triglyceride Level: Borderline high (150-199)
Classification of triglyceride level according to the ATP III guidelines.
HDL Level: High (≥60)
Classification of HDL level according to the ATP III guidelines.
- HDL ≥60 mg/dL counts as a "negative" risk factor; its presence removed one risk factor from the total count.
Total Cholesterol Level: Desirable (<200)
Classification of total cholesterol level according to the ATP III guidelines.
Literature
- NCEP 2004 Update to LDL Guidelines — National Heart, Lung, and Blood Institute
- ATP III Guidelines AT-A-Glance Quick Desk Reference — National Cholesterol Education Program
- Comparison of LDL-cholesterol direct measurement with the estimate using the Friedewald formula in a sample of 10,664 patients. Arq Bras Cardiol. 2004 Dec;83(6):482-7; 476-81. — Cordova CM, Schneider CR, Juttel ID, Cordova MM.
