1. What is the Friedewald Equation?

The Friedewald equation estimates LDL cholesterol (LDL-C) from total cholesterol (TC), HDL cholesterol (HDL-C), and triglycerides (TG). It provides a practical method for LDL-C estimation without requiring direct measurement.

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: Accurate LDL-C estimation is crucial for assessing cardiovascular risk, guiding lipid-lowering therapy, and monitoring treatment effectiveness.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (greater than 0). For accurate results, measurements should be taken from a fasting blood sample.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald equation not accurate?
A: The equation is less accurate when triglyceride levels are above 400 mg/dL, in non-fasting samples, or in certain medical conditions.

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

Q3: Should this be used for clinical decision making?
A: While useful for screening, direct LDL-C measurement is preferred for precise clinical decision making, especially in high-risk patients.

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

Q5: How often should LDL-C be measured?
A: Frequency depends on individual risk factors, but generally every 4-6 weeks when starting treatment and every 3-12 months for monitoring.