Should I Test My ApoB?
Last updated on February 1, 2025
Overview
ApoB (Apolipoprotein B) is a key structural protein found in several atherogenic lipoproteins including VLDL, IDL, LDL, and chylomicrons. Each lipoprotein particle contains exactly one ApoB molecule, making ApoB levels a direct measure of atherogenic particle count. These particles are considered atherogenic because they can penetrate and get trapped in arterial walls through ApoB’s interaction with proteoglycans, leading to plaque formation. ApoB levels can be measured through a standard blood test, though it must be specifically requested. Management options include lifestyle changes (exercise, diet modification, weight management) and medications, with PCSK9 inhibitors and statins providing the most significant reductions. Various supplements also claim to lower ApoB.
What is ApoB, and why is ApoB important?
ApoB (Apolipoprotein B) is a protein that forms the main structural component of atherogenic lipoproteins, including LDL (low-density lipoprotein) cholesterol, making it a key indicator of cardiovascular risk. Each atherogenic particle contains exactly one ApoB molecule, so measuring ApoB levels provides a more accurate count of potentially harmful lipoproteins than traditional cholesterol tests. High levels of ApoB are associated with an increased risk of atherosclerosis and cardiovascular disease, as these particles can penetrate arterial walls and contribute to plaque formation.
What makes ApoB atherogenic?
Atherogenic means “promoting the formation of fatty deposits in arteries” (atherosclerosis). ApoB is considered atherogenic because:
• Each ApoB-containing lipoprotein particle is capable of penetrating the arterial wall and becoming trapped there
• Once trapped, these particles deposit their cholesterol and other lipids inside the arterial wall
• These deposits trigger an inflammatory response where immune cells (especially macrophages) try to clear the lipids
• The macrophages can become overloaded with lipids, turning into “foam cells”
• This process leads to the formation of atherosclerotic plaques
What makes ApoB particularly important is that you need the ApoB protein for this process to occur—it’s not just about the cholesterol content. The ApoB protein interacts with proteoglycans (proteins with long sugar chains attached to them) in the arterial wall, which is what allows the particles to get trapped there in the first place. These proteoglycans act like molecular velcro, binding to specific regions of the ApoB protein and retaining the lipoprotein particles in the vessel wall. The ability of ApoB to directly mediate particle retention in arterial walls explains why ApoB particle number is often considered a better predictor of cardiovascular risk than just cholesterol levels.
Which lipoproteins contain ApoB?
The lipoproteins that contain ApoB are:
• VLDL (Very Low-Density Lipoprotein): Contains ApoB-100
• IDL (Intermediate-Density Lipoprotein): Contains ApoB-100
• LDL (Low-Density Lipoprotein): Contains ApoB-100
• Chylomicrons: Contains ApoB-48, a shorter form of ApoB
How do I test ApoB?
Labs measure ApoB in blood collected through a standard blood draw. Any doctor can order the test, but you often need to specifically request it since many standard lipid panels don’t include ApoB. Major labs like Quest and LabCorp perform ApoB testing, and most insurance plans cover it, especially if you have risk factors for heart disease. Labcorp On Demand, for example, offers the ApoB test as part of its “Complete Heart Health Test” for $169.
What behavioral changes decrease ApoB?
Regular aerobic exercise, replacing saturated fats with mono- and polyunsaturated fats, increasing soluble fiber intake through foods like oats and legumes, reducing refined carbohydrates and sugars, limiting alcohol, and maintaining a healthy weight all help reduce ApoB levels. These changes work by decreasing liver production of ApoB-containing lipoproteins and enhancing their clearance from the bloodstream.
What medications lower ApoB?
PCSK9 inhibitors provide the strongest ApoB reduction (50-60%) by preventing LDL receptor degradation. Statins offer the next most potent reduction (30-50%) by increasing LDL receptor activity. Ezetimibe reduces ApoB by about 15% by blocking cholesterol absorption. Bempedoic acid lowers ApoB by reducing liver cholesterol synthesis. GLP-1 receptor agonists provide modest ApoB reduction. Two newer medications—inclisiran (a siRNA targeting PCSK9) and evinacumab (an ANGPTL3 inhibitor)—can also significantly reduce ApoB levels.
What alternative products claim to lower ApoB?
Various supplements and natural products specifically claim to lower ApoB, including red yeast rice, plant sterols and stanols, berberine, artichoke extract, bergamot, and beta-glucans from oats. Marketers also promote niacin, curcumin, and garlic extracts as ApoB-lowering supplements.
Conclusion
ApoB measurement marks a significant advancement in cardiovascular risk assessment by directly quantifying the number of atherogenic lipoprotein particles, rather than simply assessing their cholesterol content. Because each atherogenic particle—whether LDL, VLDL, IDL, or Lp(a)—carries a single ApoB molecule, measuring ApoB provides an accurate count of these particles. This precision helps explain why individuals with similar LDL cholesterol levels may have markedly different cardiovascular risks due to differences in the number of ApoB-containing particles. Moreover, this insight has informed the development of targeted therapies, such as PCSK9 inhibitors, which effectively lower the levels of ApoB-containing particles and thereby reduce cardiovascular risk.