What does the Apolipoprotein A-1 test measure?

Why is Apolipoprotein A-1 measured?

ApoA-1 is a direct measure of the protein that mediates HDL's cardioprotective functions — reverse cholesterol transport, anti-inflammatory and anti-oxidative effects, and endothelial support. Low ApoA-1 is an independent predictor of coronary artery disease and cardiovascular events, often providing risk discrimination beyond HDL cholesterol concentration alone because HDL-C reflects only the cholesterol cargo whereas ApoA-1 quantifies particle number. It is particularly useful when HDL-C and triglycerides are discordant or when assessing residual risk in patients on lipid-modifying therapy.

Reference ranges

Standard reference

Approximately >120 mg/dL in men and >140 mg/dL in women; laboratory- and population-specific.

Functional medicine optimal

Cardiovascular risk reduction is associated with ApoA-1 concentrations >150 mg/dL in men and >160 mg/dL in women; some lipid specialists target higher thresholds in high-risk patients.

Units

mg/dL, g/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.