How do you lower an elevated ApoB?

ApoB is a protein found on virtually all 'bad' fat particles in the blood, including LDL. The higher the ApoB concentration, the more of those particles are circulating. A high ratio of ApoB relative to the 'protective' protein ApoA1 is associated, in a global observational study across 32 countries, with an almost twice as high risk of ischaemic stroke (odds ratio 1.84). That is an association, not proof that lowering ApoB also prevents strokes, but it illustrates why doctors take this number seriously.

The strongest pharmaceutical evidence belongs to the so-called PCSK9 inhibitors. Alirocumab and inclisiran both work by inhibiting a liver enzyme that normally breaks down LDL receptors, allowing the liver to remove more LDL and ApoB-containing particles from the blood. Inclisiran is an injection given just twice a year and significantly lowers ApoB (consistent with an LDL reduction of approximately 44%) in people for whom statins alone are insufficient. Alirocumab, in cardiac patients following acute coronary syndrome, not only reduced ApoB particles but also their pro-inflammatory properties, and decreased the risk of serious cardiovascular events. Both drugs are approved treatments for eligible patients and are well tolerated.

In terms of diet, the evidence for oats is the most thoroughly developed. A meta-analysis of 58 randomised trials involving nearly 4,000 participants shows that approximately 3.5 grams of beta-glucan per day, equivalent to a large bowl of oatmeal, lowers ApoB by an average of 0.03 g/l. That is statistically reliable but absolutely modest. For people with a mildly elevated ApoB this is a meaningful dietary step, but for those with a substantially elevated value, diet alone is insufficient.

Muvalaplin is an experimental oral drug developed primarily to lower lipoprotein(a), but in a 12-week phase 2 study it also lowered ApoB in a dose-dependent manner: by approximately 9% at the lowest dose and 16% at the highest dose. The drug was well tolerated, but whether it prevents cardiovascular events has not yet been studied. It is therefore at an early stage of research and is not an available treatment option.