Apolipoprotein B

The normal reference range for Apolipoprotein B is Below 0.9 g/L is generally desirable; below 0.65 g/L is the target for people at high cardiovascular risk. There is no meaningful "too low" — lower ApoB means fewer atherogenic particles. ApoB does not require fasting, unlike a standard lipid panel.. Reference ranges may vary between laboratories, so always consult your healthcare provider for interpretation.

Offers a more accurate assessment of cardiovascular risk than standard lipid tests, as it reflects the actual number of potentially harmful particles.

High ApoB means a high number of atherogenic (artery-clogging) particles, which drives cardiovascular risk more directly than LDL cholesterol concentration alone. Common causes include a diet high in saturated and trans fats, familial hypercholesterolaemia (an inherited condition affecting roughly 1 in 250 Australians), type 2 diabetes and insulin resistance, metabolic syndrome, hypothyroidism, kidney disease (nephrotic syndrome) and obesity. ApoB is especially useful in people with high triglycerides or diabetes, where LDL cholesterol can underestimate true particle burden.

Low ApoB is generally favourable and is the goal of lipid-lowering treatment with statins, ezetimibe or PCSK9 inhibitors. Naturally low levels can occur with an overactive thyroid (hyperthyroidism), malnutrition, severe liver disease, malabsorption, or rare genetic conditions (hypobetalipoproteinaemia). Unless caused by underlying illness, low ApoB is not a health concern.

ApoB is measured as part of a cardiovascular risk assessment, often alongside a lipid panel. If you start or change lipid-lowering therapy, recheck after 6-12 weeks, then every 6-12 months once stable. People with diabetes, a family history of early heart disease, or known high Lp(a) benefit from ApoB rather than relying on LDL alone.