ApoB

Apolipoprotein B (ApoB) is the main protein in the types of cholesterol particles that are most associated with cardiovascular risk, such as LDL-C. ApoB constitutes approximately 20-25% of the total weight of LDL-C particles and it is a more reliable measure of the level of these cholesterol types in the blood than more widely used measures which are based on molecular weight. Unsurprisingly, the risk association of APOB with cardiovascular risk is very similar to the risk associated with raised LDL-C levels.

ApoB levels have been significantly associated with the risk of atherosclerosis and cardiovascular events such as heart attacks and strokes in several large-scale epidemiological studies. The primary advantage of ApoB over LDL-C is that it does not vary as much between measurements or after eating so it is a more precise indicator of risk. It therefore forms a key part of our assessment of your atherosclerosis risk.

Guidelines on the normal and optimum ranges of ApoB differ significantly between different sources and health authorities. We have defined optimal levels as <0.8 g/L since based on guidelines produced by the European Atherosclerosis Society and the American Heart Association. The same guidelines note that ApoB levels should be reported as at risk at more than 1 g/L so this forms the upper limit of our normal range. It should be noted that some guidelines recommend ApoB targets as low as 0.65 g/L for people who are at very high risk of heart attacks or strokes however this is usually only achievable through the use of medications such as statins.