1. What is the Friedewald Equation?

The Friedewald equation is a formula used to estimate LDL cholesterol (LDL-C) levels from total cholesterol (TC), HDL cholesterol (HDL-C), and triglyceride (TG) measurements. It provides a practical alternative to direct LDL measurement when resources are limited.

2. How Does the Calculator Work?

The calculator uses the Friedewald equation:

Where:

• \( TC \) — Total cholesterol (mg/dL)
• \( HDL-C \) — HDL cholesterol (mg/dL)
• \( TG \) — Triglycerides (mg/dL)

Explanation: The equation estimates LDL cholesterol by subtracting HDL cholesterol and one-fifth of triglycerides from total cholesterol.

3. Importance of LDL-C Calculation

Details: LDL cholesterol is a major risk factor for cardiovascular disease. Accurate estimation helps assess cardiovascular risk and guide treatment decisions for cholesterol management.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (greater than 0). Note: This equation is not accurate when triglyceride levels exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald equation not accurate?
A: The equation becomes less accurate when triglyceride levels exceed 400 mg/dL or in non-fasting samples.

Q2: What are optimal LDL cholesterol levels?
A: Optimal LDL levels are generally below 100 mg/dL, though targets may vary based on individual cardiovascular risk factors.

Q3: How does this compare to direct LDL measurement?
A: Direct measurement is more accurate, especially when triglycerides are elevated, but the Friedewald equation provides a good estimate in most cases.

Q4: Are there alternative equations for LDL estimation?
A: Yes, the Martin/Hopkins equation and other methods may provide more accurate estimates in certain populations.

Q5: Should fasting be required for this calculation?
A: Yes, triglyceride levels are affected by recent food intake, so fasting samples (9-12 hours) are recommended for accurate results.