Nonfasting Lipid Testing: The New Standard for Cardiovascular Risk Assessment

Key Points

• Large studies show minimal variation in total cholesterol and HDL cholesterol with more noticeable changes in LDL cholesterol and triglycerides after eating.
• Non-HDL cholesterol from nonfasting samples is a better predictor of cardiovascular risk than LDL cholesterol.
• Canadian guidelines recommend nonfasting lipid profiles for cholesterol and triglycerides.
• Nonfasting testing enhances convenience, safety, and timeliness of screenings.

Introduction

• Hypercholesterolemia is a modifiable risk factor for coronary heart disease.
• Traditionally, fasting was required for lipid profiles due to concerns of variability from eating.
• Recent evidence supports nonfasting lipid testing as equally or more effective.

Evidence from Studies

• Studies from Copenhagen and Calgary show minor variations in lipid levels postprandially.
  • Triglycerides increase by about 20% and LDL cholesterol decreases by up to 10%.
  • Total cholesterol, HDL cholesterol, and apolipoprotein B100 remain stable.
• Nonfasting lipid levels better predict coronary heart disease and stroke risk.
  • Captures atherogenic effects of remnant lipoproteins.
  • Non-HDL cholesterol is a better risk predictor than LDL cholesterol.

Implementation in Guidelines

• Adopted in Denmark since 2009.
• In Canada, Alberta reported nonfasting profiles in 2014, with nationwide guideline recommendations since 2015.
• Physicians can still request fasting, but nonfasting is becoming the standard.

Practical Benefits

• Patients can have tests done at any time, improving convenience and reducing risks for diabetic or frail individuals.
• Nonfasting does not affect Framingham risk score calculations.
• Could negate the need for fasting in routine bloodwork due to glycated hemoglobin testing for diabetes.

Clinical Considerations

• Non-HDL cholesterol is preferred over LDL in nonfasting states.
• Guidelines target non-HDL cholesterol levels of <2.6 mmol/L for moderate/high-risk patients.
• Repeat testing is recommended if nonfasting triglycerides exceed 4.5 mmol/L.

Conclusion

• Transition to nonfasting lipid testing is supported by evidence showing minimal variation in lipid levels post-eating.
• Benefits include better cardiovascular risk assessment and practical advantages for patients.

References

• References to several studies and guidelines that support the adoption and benefits of nonfasting lipid testing.