1. What is the Friedewald Formula?

The Friedewald formula is a widely used equation for estimating LDL cholesterol levels from total cholesterol, HDL cholesterol, and triglyceride measurements. It provides a cost-effective alternative to direct LDL measurement in most clinical situations.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

• \( TC \) — Total cholesterol (mmol/L)
• \( HDL-C \) — HDL cholesterol (mmol/L)
• \( TG \) — Triglycerides (mmol/L)

Explanation: The formula estimates LDL cholesterol by subtracting HDL cholesterol and VLDL cholesterol (estimated as TG/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 lipid-lowering therapy decisions.

4. Using the Calculator

Tips: Enter all values in mmol/L. Ensure triglyceride levels are below 4.5 mmol/L for accurate results. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

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

Q2: What are optimal LDL levels?
A: Optimal LDL levels are generally below 2.6 mmol/L, though target levels may vary based on individual cardiovascular risk factors.

Q3: How should blood samples be collected?
A: Fasting samples (9-12 hours) are preferred for accurate triglyceride measurement, which affects LDL calculation.

Q4: Are there alternative methods for LDL measurement?
A: Yes, direct LDL measurement is available and recommended when triglyceride levels are elevated (>4.5 mmol/L).

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