What is a healthy ApoB level?

There is no fixed universal threshold, but a large Danish study of more than 104,000 people shows that the risk of ischaemic stroke already rises measurably above 82 mg/dL. As many as 16.3% of all ischaemic strokes in that group were associated with ApoB above that level. By comparison, elevated LDL cholesterol explained only 6.8%. That makes 82 mg/dL a useful threshold to keep in mind.

A Polish hospital study of nearly 10,600 patients used 100 mg/dL as the cut-off for 'elevated'. The median value in that group was 78 mg/dL. Patients with the highest cardiovascular risk had on average lower values, most likely due to lipid-lowering medication. This shows that 'normal' in hospital data is already shaped by treatment.

ApoB measures something different from LDL cholesterol. LDL tells you how much cholesterol is carried inside harmful fat particles. ApoB counts the actual number of those particles. In nearly a quarter of the Polish patients, ApoB gave a different picture than LDL. If you have many small, cholesterol-poor LDL particles, your LDL may look 'normal' while your ApoB is too high.

ApoB is also a better gauge of the effect of treatment. A meta-analysis of 27 studies showed that the reduction in ApoB was most strongly associated with shrinkage of narrowings in the coronary arteries, more so than the reduction in LDL or non-HDL cholesterol. Targeting ApoB therefore appears more effective if you want to reverse arterial hardening.

At a young age the consequences are not always visible yet. A small study of 13 children and young adults with a hereditary condition that structurally raises ApoB found no demonstrable arterial hardening or vascular stiffness. Because of the small number of participants, this provides no certainty about long-term risk.