1. What is the Friedewald Formula?

The Friedewald formula is a widely used method for estimating LDL cholesterol levels from measurements of total cholesterol, HDL cholesterol, and triglycerides. It provides a calculated LDL value without requiring direct measurement.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

• \( LDL-C \) — Low-density lipoprotein cholesterol (mg/dL)
• \( TC \) — Total cholesterol (mg/dL)
• \( HDL-C \) — High-density lipoprotein cholesterol (mg/dL)
• \( TG \) — Triglycerides (mg/dL)

Explanation: The formula 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 in assessing cardiovascular risk and guiding 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 formula is not accurate when triglyceride levels exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When should the Friedewald formula not be used?
A: The formula should not be used when triglyceride levels are above 400 mg/dL, as it becomes less accurate. Direct LDL measurement is recommended in such cases.

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: The calculated method is less expensive and widely used, but direct measurement may be more accurate, especially when triglycerides are elevated.

Q4: Are there limitations to this formula?
A: Besides high triglyceride limitations, the formula may be less accurate in certain populations such as those with diabetes or very low LDL levels.

Q5: Should fasting be required for this calculation?
A: Yes, for accurate results, blood should be drawn after a 9-12 hour fast, as triglyceride levels can be significantly affected by recent food intake.