1. What Is LDL Calculated Blood Test?

The LDL calculated blood test estimates low-density lipoprotein (LDL) cholesterol levels using the Friedewald equation. It's commonly used when direct LDL measurement isn't available, providing an assessment of "bad" cholesterol levels which is important for cardiovascular risk evaluation.

2. How Does the Calculator Work?

The calculator uses the Friedewald equation:

Where:

• \( LDL \) — Low-density lipoprotein cholesterol (mg/dL)
• \( TC \) — Total cholesterol (mg/dL)
• \( HDL \) — High-density lipoprotein cholesterol (mg/dL)
• \( TG \) — Triglycerides (mg/dL)

Explanation: The equation estimates LDL 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 atherosclerosis and cardiovascular disease. Monitoring LDL levels helps assess cardiovascular risk and guide lipid-lowering therapy.

4. Using the Calculator

Tips: Enter all values in mg/dL. The equation is valid when triglycerides are below 400 mg/dL. For higher TG levels, direct LDL measurement is recommended.

5. Frequently Asked Questions (FAQ)

Q1: Why calculate LDL instead of measuring it directly?
A: Calculation is less expensive and sufficient for most clinical situations when triglycerides are normal.

Q2: What are normal LDL values?
A: Optimal 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 is the Friedewald equation not accurate?
A: When triglycerides are >400 mg/dL, in non-fasting samples, or with certain conditions like type III hyperlipidemia.

Q4: Are there newer equations than Friedewald?
A: Yes, the Martin/Hopkins equation may be more accurate, especially at low LDL and high TG levels.

Q5: Should I fast before lipid testing?
A: Traditionally yes, but recent guidelines suggest non-fasting samples may be acceptable for many patients.