How to Calculate Non-HDL Cholesterol
Non-HDL cholesterol is calculated by subtracting HDL cholesterol from total cholesterol: Non-HDL-C = Total Cholesterol - HDL Cholesterol. 1
The Simple Calculation
- The formula is straightforward: Non-HDL-C = TC - HDL-C 1
- This calculation can be performed using values from any standard lipid panel, whether fasting or non-fasting 1
- No additional laboratory testing or cost is required beyond the routine lipid panel 2
Why Non-HDL Cholesterol Matters
- Non-HDL cholesterol represents all atherogenic (cholesterol-carrying) particles, including LDL, VLDL, IDL, and remnant lipoproteins 1
- It is superior to LDL cholesterol alone for predicting cardiovascular events and coronary heart disease risk 1, 3
- Non-HDL-C is highly correlated with apolipoprotein B levels, which directly measure the number of atherogenic particles 1
Clinical Advantages Over LDL Cholesterol
- Non-HDL-C does not require fasting blood samples, making it more convenient for patients and clinicians 1, 3
- It remains accurate even when triglycerides are elevated (>4.5 mmol/L or 400 mg/dL), whereas calculated LDL cholesterol becomes invalid at these levels 1, 4
- The calculation avoids the limitations of the Friedewald formula, which can be inaccurate when LDL levels are very low or triglycerides are high 1, 4
When to Use Non-HDL Cholesterol
- Use non-HDL-C as a secondary treatment target when triglycerides are ≥200 mg/dL (2.3 mmol/L) 1
- Non-HDL-C thresholds should be set 30 mg/dL higher than corresponding LDL-C goals (for example, if LDL-C goal is 100 mg/dL, non-HDL-C goal is 130 mg/dL) 1
- For universal screening in children and adolescents aged 9-11 years and 17-21 years, non-HDL-C can be calculated from a non-fasting lipid panel 1
Important Clinical Caveats
- While non-HDL-C is valuable for risk assessment, LDL cholesterol remains the primary treatment target based on the overwhelming evidence from randomized controlled trials 1
- In patients with very high triglycerides (>500 mg/dL), non-HDL-C may include cholesterol from larger, less atherogenic chylomicrons and large VLDL particles, potentially overestimating cardiovascular risk 5
- Always interpret non-HDL-C in the context of the complete lipid profile, not in isolation 1