Friedewald Formula:
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The Friedewald formula calculates LDL cholesterol (LDL-C) from total cholesterol, HDL cholesterol, and triglycerides. It provides an estimate of LDL levels without requiring direct measurement, which is useful for cardiovascular risk assessment.
The calculator uses the Friedewald formula:
Where:
Explanation: The formula estimates LDL cholesterol by subtracting HDL and VLDL (estimated as TG/5) from total cholesterol.
Details: LDL cholesterol is a major risk factor for cardiovascular disease. Accurate estimation helps in risk stratification and guiding lipid-lowering therapy decisions.
Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (greater than 0). Note: This formula is not accurate when triglycerides exceed 400 mg/dL.
Q1: Why use the Friedewald formula?
A: It provides a simple, cost-effective way to estimate LDL cholesterol without requiring specialized direct measurement techniques.
Q2: What are the limitations of this formula?
A: It becomes inaccurate when triglycerides exceed 400 mg/dL, in non-fasting samples, or in certain metabolic conditions.
Q3: What are optimal LDL levels?
A: Generally, LDL below 100 mg/dL is optimal, 100-129 mg/dL is near optimal, 130-159 mg/dL is borderline high, and above 160 mg/dL is high.
Q4: When should direct LDL measurement be used instead?
A: Direct measurement is recommended when triglycerides are >400 mg/dL, in patients with diabetes, or when precise LDL quantification is needed.
Q5: How often should LDL be measured?
A: Frequency depends on individual risk factors, but generally every 4-6 years for adults without risk factors, and more frequently for those with elevated risk.