What are the normal values for a lipid panel?

Normal Values for Lipid Panel

Normal lipid values for adults include total cholesterol <190 mg/dL, LDL cholesterol <120 mg/dL, HDL cholesterol ≥45 mg/dL, non-HDL cholesterol <150 mg/dL, and triglycerides <115 mg/dL. 1

Standard Lipid Panel Components

A standard lipid panel consists of the following measurements:

1. Total Cholesterol (TC)

   • Acceptable: <190 mg/dL
   • Borderline-High: 190-224 mg/dL
   • High: ≥225 mg/dL

2. Low-Density Lipoprotein Cholesterol (LDL-C)

   • Acceptable: <120 mg/dL
   • Borderline-High: 120-159 mg/dL
   • High: ≥160 mg/dL

3. High-Density Lipoprotein Cholesterol (HDL-C)

   • Low: <40 mg/dL
   • Borderline-Low: 40-44 mg/dL
   • Acceptable: ≥45 mg/dL

4. Triglycerides

   • Acceptable: <115 mg/dL
   • Borderline-High: 115-149 mg/dL
   • High: ≥150 mg/dL

5. Non-HDL Cholesterol (calculated as TC minus HDL-C)

   • Acceptable: <150 mg/dL
   • Borderline-High: 150-189 mg/dL
   • High: ≥190 mg/dL

Important Considerations for Lipid Testing

Fasting vs. Non-fasting Samples

• Either fasting or non-fasting plasma lipid profiles can be used to estimate cardiovascular risk and document baseline LDL-C levels 1
• Non-fasting samples are generally adequate for initial assessment
• If triglycerides are ≥400 mg/dL on a non-fasting sample, a fasting lipid panel should be performed 1

LDL-C Calculation Methods

• Standard calculation: Friedewald formula = TC - HDL-C - (Triglycerides/5)
• This formula becomes less accurate when:
  • LDL-C is <70 mg/dL
  • Triglycerides are >150 mg/dL
  • Triglycerides are <100 mg/dL (may overestimate LDL-C by approximately 12 mg/dL) 2
• Direct LDL-C measurement is reasonable when LDL-C is <70 mg/dL for improved accuracy 1

Special Considerations

• Lipid measurements should be delayed until ≥3 weeks after an infection 1
• Family history of premature cardiovascular disease or genetic hyperlipidemia warrants a fasting lipid profile for initial evaluation 1
• Non-HDL cholesterol is increasingly recognized as an important marker of cardiovascular risk, especially in patients with elevated triglycerides 3

Clinical Significance

Understanding normal lipid values is crucial for:

1. Risk Assessment: Abnormal lipid values contribute to atherosclerotic cardiovascular disease risk
2. Treatment Decisions: Lipid values guide decisions about lifestyle modifications and medication therapy
3. Monitoring Response: Baseline and follow-up lipid panels help assess response to interventions

While these values represent general guidelines for adults, it's worth noting that some research suggests that physiologically normal LDL-C may actually be in the range of 50-70 mg/dL based on studies of hunter-gatherers, human neonates, and wild mammals who do not develop atherosclerosis 4. However, current clinical guidelines maintain the target values listed above.