HDL Function Panel

This panel measures the key proteins that make up and regulate HDL and assesses how effectively HDL is doing its job. While traditional lipid panels only measure the amount of HDL cholesterol in your blood, this test digs deeper to answer a more meaningful question: Is your HDL actually protecting your arteries?

The panel includes Apolipoprotein A1 (APOA1), the main structural and functional protein in HDL particles. It acts like a shuttle, helping to remove cholesterol from artery walls and deliver it to the liver for disposal—a process called reverse cholesterol transport. High levels of APOA1 are generally associated with better HDL function and lower cardiovascular risk, while low levels can indicate impaired cholesterol clearance, even if your HDL cholesterol level is normal.

The panel also includes the Apolipoprotein C family—APOC1, APOC2, APOC3, and APOC4. These smaller proteins help regulate how your body processes fats (triglycerides) and HDL. For example:

• APOC1 can inhibit enzymes involved in fat breakdown and influence HDL’s anti-inflammatory functions.
• APOC2 is essential for activating lipoprotein lipase, an enzyme that breaks down triglycerides.
• APOC3 often slows down fat clearance and has been linked to higher cardiovascular risk, especially when elevated.
• APOC4, although less well studied, is believed to play a role in lipid transport and metabolism.

Together, these apolipoproteins reflect how your body is managing fat and cholesterol on a molecular level—offering a more refined picture of metabolic and cardiovascular health than standard cholesterol numbers can.

Finally, the HDLfx pCAD Score measures how well your HDL actually removes cholesterol from cells in the artery wall. This is a functional assay—not just a count. A low HDLfx score may indicate preclinical coronary artery disease (pCAD), meaning early plaque buildup is occurring even if traditional lab results appear normal. This is especially useful for uncovering hidden risk in people who have “good” HDL numbers but still develop heart disease.