1. What is the Friedewald Formula?

The Friedewald formula is a widely used method for estimating LDL cholesterol levels without direct measurement. It calculates LDL based on total cholesterol, HDL, and triglyceride levels.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

• Total Cholesterol — Total cholesterol level in mmol/L
• HDL — High-density lipoprotein level in mmol/L
• Triglycerides — Triglyceride level in mmol/L

Explanation: The formula estimates LDL cholesterol by subtracting HDL and VLDL (estimated as triglycerides divided by 2.2) from total cholesterol.

3. Importance of LDL Calculation

Details: LDL cholesterol is a major risk factor for cardiovascular disease. Accurate estimation helps in assessing cardiovascular risk and guiding treatment decisions.

4. Using the Calculator

Tips: Enter total cholesterol, HDL, and triglycerides in mmol/L. All values must be positive and valid. Note: This formula is not accurate when triglyceride levels exceed 4.5 mmol/L.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald formula not accurate?
A: The formula becomes less accurate when triglyceride levels exceed 4.5 mmol/L, in non-fasting samples, or in certain medical conditions.

Q2: What are normal LDL values?
A: Optimal LDL is below 2.6 mmol/L. Borderline high is 2.6-3.3 mmol/L, high is 3.4-4.1 mmol/L, and very high is above 4.1 mmol/L.

Q3: Are there alternatives to the Friedewald formula?
A: Yes, direct LDL measurement or other calculation methods like the Martin/Hopkins method may be used when triglycerides are elevated.

Q4: 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 affected by recent food intake.

Q5: What are the limitations of calculated LDL?
A: Calculated LDL may be inaccurate in patients with very high triglycerides, diabetes, renal disease, or other metabolic disorders.