1. What is the NIH LDL-C Equation?

The NIH LDL-C equation, developed by Sampson et al., provides a more accurate method for calculating LDL cholesterol compared to the traditional Friedewald formula, especially for patients with low LDL levels or high triglycerides.

2. How Does the Calculator Work?

The calculator uses the NIH LDL-C equation:

Where:

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

Explanation: This equation provides a more accurate estimation of LDL cholesterol across a wider range of triglyceride values compared to traditional methods.

3. Importance of LDL-C Calculation

Details: Accurate LDL cholesterol measurement is crucial for assessing cardiovascular risk, guiding treatment decisions, and monitoring the effectiveness of lipid-lowering therapies.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (greater than 0).

5. Frequently Asked Questions (FAQ)

Q1: Why use the NIH equation instead of Friedewald formula?
A: The NIH equation provides more accurate results, especially when triglycerides are high (>400 mg/dL) or LDL is low (<70 mg/dL).

Q2: What are optimal LDL cholesterol levels?
A: Optimal LDL is <100 mg/dL, near optimal is 100-129 mg/dL, borderline high is 130-159 mg/dL, high is 160-189 mg/dL, and very high is ≥190 mg/dL.

Q3: When should this calculation be used?
A: This calculation is particularly useful when direct LDL measurement is not available or when triglyceride levels are elevated.

Q4: Are there limitations to this equation?
A: While more accurate than Friedewald, it may still have limitations in certain populations such as those with very high triglycerides (>800 mg/dL).

Q5: Should fasting samples be used?
A: Yes, for accurate lipid measurements including triglycerides, a 9-12 hour fasting sample is recommended.