What does the Apolipoprotein B test measure?

Why is Apolipoprotein B measured?

ApoB is recognised as a superior marker of cardiovascular risk compared to LDL cholesterol or non-HDL cholesterol, particularly in states of hypertriglyceridaemia, metabolic syndrome, and discordance between particle number and cholesterol content. Guidelines from the European Atherosclerosis Society, the Canadian Cardiovascular Society, and emerging consensus statements position ApoB as a primary target for lipid-lowering therapy; each increment of approximately 10 mg/dL in ApoB carries residual risk even when LDL cholesterol appears controlled. It is especially valuable when LDL cholesterol underestimates atherogenic burden — small dense LDL, elevated remnants, or high Lp(a) — and it guides treatment intensity and the adequacy of response to lipid-lowering drugs.

Reference ranges

Standard reference

Typically <90 mg/dL (SI <0.9 g/L) desirable; laboratory-specific intervals vary.

Functional medicine optimal

International guidelines suggest desirable ApoB <80 mg/dL for moderate cardiovascular risk, <65 mg/dL for high risk, and <55 mg/dL for very high risk or secondary prevention; these thresholds parallel LDL cholesterol targets but reflect particle burden more directly.

Units

mg/dL, g/L

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