1. What is the Friedewald Formula?

The Friedewald formula is a widely used equation to estimate LDL cholesterol levels without direct measurement. It calculates LDL-C based on total cholesterol, HDL cholesterol, and triglyceride levels.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

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

Explanation: The formula estimates LDL cholesterol by subtracting HDL and VLDL (estimated as TG/5) from total cholesterol.

3. Importance of LDL Calculation

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

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 less accurate when triglycerides exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald formula not accurate?
A: The formula becomes less reliable when triglyceride levels are above 400 mg/dL, in non-fasting samples, or in patients with certain metabolic disorders.

Q2: What are optimal LDL levels?
A: Generally, LDL below 100 mg/dL is optimal, below 70 mg/dL for high-risk patients, but targets should be individualized based on overall cardiovascular risk.

Q3: How should blood samples be collected?
A: For accurate results, a 9-12 hour fasting sample is recommended, as triglyceride levels are affected by recent food intake.

Q4: Are there alternative methods for LDL measurement?
A: Yes, direct LDL measurement is available and may be more accurate in certain situations, particularly when triglycerides are elevated.

Q5: Can this calculator be used for children?
A: The Friedewald formula is primarily validated for adults. Pediatric LDL assessment may require different approaches and interpretation.