1. What is the NIH/Sampson LDL Equation?

The NIH/Sampson equation is a novel method for estimating LDL cholesterol that provides more accurate results than the traditional Friedewald formula, especially at triglyceride levels up to 800 mg/dL and LDL levels below 70 mg/dL.

2. How Does the Calculator Work?

The calculator uses the NIH/Sampson equation:

Where:

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

Explanation: This equation was developed using a large dataset from the NIH and provides more accurate LDL estimation across a wider range of lipid values compared to traditional methods.

3. Importance of LDL Calculation

Details: Accurate LDL cholesterol measurement is crucial for cardiovascular risk assessment and guiding lipid-lowering therapy decisions. The NIH/Sampson equation reduces misclassification of patients compared to the Friedewald formula.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid positive numbers. This equation is validated for use with triglyceride levels up to 800 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: Why use NIH/Sampson instead of Friedewald formula?
A: The NIH/Sampson equation provides more accurate LDL estimation, especially at low LDL levels and higher triglyceride levels where the Friedewald formula tends to underestimate LDL.

Q2: What are the limitations of this equation?
A: While validated up to TG=800 mg/dL, direct LDL measurement may still be preferred at very high triglyceride levels. The equation may also be less accurate in certain ethnic populations.

Q3: When should this equation not be used?
A: Not recommended for patients with dysbetalipoproteinemia (type III hyperlipoproteinemia) or those with unusual lipoprotein patterns.

Q4: How does this compare to direct LDL measurements?
A: The NIH/Sampson equation shows excellent correlation with direct LDL measurements and often performs better than the Friedewald formula.

Q5: Is fasting required for accurate results?
A: For most accurate results, a 12-hour fasting sample is recommended, though the equation can be used with non-fasting samples with some limitations.