What are normal values for Lipoprotein(a) (Lp(a)) levels?

Normal Values for Lipoprotein(a)

There is no single "normal" value for Lp(a), but rather risk-based thresholds: levels <30 mg/dL (or <75 nmol/L) are considered low-risk and represent approximately the 75th percentile in Caucasian populations, while levels ≥30 mg/dL indicate where cardiovascular risk begins to increase above baseline. 1, 2

Understanding Lp(a) Distribution in the Population

The distribution of Lp(a) is highly skewed, making traditional "normal ranges" less clinically useful than risk-based thresholds:

• Median Lp(a) levels in the general population are approximately 10-15 mg/dL, with 56% of individuals having values in the 0-10 mg/dL range 1, 3
• The 75th percentile is approximately 22-30 mg/dL in both men and women 1, 3
• The 90th percentile is approximately 38 mg/dL 3
• Values vary substantially by ethnicity, with higher levels typically seen in individuals of African descent 1

Risk-Based Thresholds (What Actually Matters Clinically)

Rather than focusing on "normal," you should interpret Lp(a) based on cardiovascular risk stratification:

Low-Risk Threshold

• <30 mg/dL (<75 nmol/L): This represents the point below which cardiovascular risk does not demonstrably increase above baseline 1, 2
• This threshold corresponds to approximately the 75th percentile in Caucasian populations 1

Intermediate-Risk Threshold

• 30-50 mg/dL (75-125 nmol/L): Borderline elevation where risk begins to increase 1, 4
• The European guidelines use >50 mg/dL (approximately 100-125 nmol/L) as the threshold for significant cardiovascular risk 1, 2

High-Risk Threshold

• ≥50 mg/dL (≥125 nmol/L): Elevated levels affecting approximately 20% of the global population and conferring substantially increased cardiovascular risk 1, 5
• This threshold warrants reclassification of patients from intermediate to higher cardiovascular risk categories 1

Very High-Risk Threshold

• ≥100 mg/dL: Particularly high risk, with some studies showing 5-8 fold increased odds of coronary heart disease at these levels 1, 6

Critical Caveats About Lp(a) Measurement

Lack of Standardization Between Laboratories

• There is large between-method variation in Lp(a) assays due to lack of a common reference material, making comparisons between laboratories difficult 7
• Each laboratory may use its own reference values, so you should interpret results in the context of the specific assay used 7
• Despite accuracy concerns, precision is sufficient for comparing values measured in the same laboratory 7

Mass vs. Molar Concentrations

• A conversion factor of 3.17 can be used (1 mg/dL = 3.17 nmol/L) when converting between mass and molar concentrations 7
• Molar concentrations are recommended but the methodology doesn't fully meet requirements for accurate molar expression 7

Stability of Lp(a) Over Time

General Stability

• Lp(a) levels are 70-90% genetically determined and remain relatively constant throughout a person's life 1, 5
• Serial monitoring is generally not necessary as levels are stable 1, 2

Exceptions Requiring Repeat Measurement

• Borderline levels (30-50 mg/dL): 51-58% of individuals with borderline Lp(a) change categories over time, with many progressing to high levels 1, 8
• Specific populations at higher risk for change: Black race, female sex, diabetes, hypertension, elevated albuminuria, or elevated LDL-C ≥100 mg/dL are associated with greater probability of Lp(a) change ≥10-20 mg/dL over time 8, 9
• Chronic kidney disease: Lp(a) levels may fluctuate in CKD patients 1, 2
• Patients on statin therapy: Statins may paradoxically increase Lp(a) levels 1, 9

Who Needs Repeat Testing

• Individuals with borderline Lp(a) (30-50 mg/dL) should be considered for repeat monitoring, particularly if they are female, Black, or have diabetes, hypertension, or albuminuria 8, 9
• Patients with normal (<30 mg/dL) or high (≥50 mg/dL) Lp(a) at baseline tend to remain in their respective categories (96.4% and 89.9% stability, respectively) 9