Should fasting status influence Lipoprotein(a) (Lp(a)) levels?

Fasting Status Does Not Significantly Influence Lipoprotein(a) Levels

Fasting status does not significantly influence Lipoprotein(a) (Lp(a)) levels, and nonfasting samples can be reliably used for Lp(a) measurement and cardiovascular risk assessment. 1

Evidence on Lp(a) and Fasting Status

Lipoprotein(a) is a modified form of LDL that possesses atherogenic potential and is considered a risk-enhancing factor for cardiovascular disease 2. Unlike other lipid parameters, Lp(a) levels remain remarkably stable regardless of food intake:

• Research demonstrates that Lp(a) levels do not change significantly in response to normal food intake, with median fasting levels of 17.3 mg/dL compared to median levels at 3-4 hours since last meal of 19.4 mg/dL (p = 0.38) 1
• The predictive value of Lp(a) for cardiovascular events is not affected by fasting status 1
• Highest versus lowest tertile of Lp(a) showed similar risk associations for ischemic heart disease whether measured <3 hours (OR 1.4) or ≥3 hours (OR 1.4) after a meal (p = 0.82) 1

Lp(a) Measurement in Clinical Practice

The American College of Cardiology/American Heart Association guidelines indicate that Lp(a) is an important risk-enhancing factor for cardiovascular disease 2:

• Relative indications for Lp(a) measurement include family history of premature ASCVD or personal history of ASCVD not explained by major risk factors 2
• An Lp(a) ≥50 mg/dL or ≥125 nmol/L may be considered a risk-enhancing factor 2
• Unlike other lipid parameters that may require fasting in certain circumstances, Lp(a) measurement can be performed in the nonfasting state 3, 1

Practical Implications for Clinical Practice

When measuring Lp(a) as part of cardiovascular risk assessment:

• No special fasting preparation is required for Lp(a) measurement 1
• Patients can have Lp(a) measured at any time of day, regardless of food intake 3, 1
• This improves patient convenience and compliance with testing 4
• For patients with diabetes, avoiding unnecessary fasting reduces the risk of hypoglycemia 3, 4

Inflammation and Lp(a)

While fasting status doesn't significantly affect Lp(a), inflammation may have a minimal impact:

• Lp(a) levels increase slightly with increasing levels of C-reactive protein (CRP): median Lp(a) levels at CRP <1 mg/L were 18.0 mg/dL, while median levels at CRP >10 mg/L were 21.1 mg/dL (p < 0.001) 1
• However, this minimal increase does not affect the ability of Lp(a) to predict cardiovascular risk 1

Comparison with Other Lipid Parameters

Unlike Lp(a), other lipid parameters may show modest changes with food intake:

• Total cholesterol: maximum change -0.2 mmol/L (8 mg/dL)
• LDL cholesterol: maximum change -0.2 mmol/L (8 mg/dL)
• HDL cholesterol: maximum change -0.1 mmol/L (4 mg/dL)
• Triglycerides: maximum change +0.3 mmol/L (26 mg/dL) 3, 5

Conclusion

For Lp(a) measurement, fasting status does not significantly influence results or alter cardiovascular risk prediction. Clinicians can confidently measure Lp(a) in nonfasting samples, which improves patient convenience without compromising the clinical utility of the test.