# ApoB

Source: https://synapse-lifestyle.com/en/reference-guide/biomarkers/apob

Unit: mg/dL

## What is ApoB?

Apolipoprotein B (ApoB) counts the number of cholesterol particles that can lodge in your blood vessels. One ApoB belongs to one particle, so it's a direct count of the 'traffic' in your blood vessels. The number of particles often predicts heart and vascular health more sharply than cholesterol alone. Lower means fewer particles that can build up: one of the strongest levers for your heart over the long term.

## Clinical frame

**ApoB counts the atherogenic particles.** Every LDL, VLDL, IDL and Lp(a) particle carries exactly one ApoB molecule, so the ApoB concentration directly reflects the number of particles that can enter the vessel wall, whereas LDL and non-HDL cholesterol only measure the cholesterol mass inside those particles [1].

That particle number drives plaque formation. Genetic and epidemiological studies show that ApoB **predicts cardiovascular risk more strongly** than LDL or non-HDL cholesterol and that the relationship is causal: when all lipids are modelled together, only ApoB remains standing [1] [2].

Its greatest added value lies in **discordance**: many small, cholesterol-poor LDL particles give a normal LDL or non-HDL cholesterol but an elevated ApoB, typically in insulin resistance, diabetes and elevated triglycerides. On a statin too, an elevated ApoB points to residual risk that LDL cholesterol misses [3].

## What moves this value?

Partly hereditary, partly lifestyle. Lots of saturated fat, low fibre, belly fat and sometimes an underactive thyroid can push it up.

More soluble fibre (oats, legumes), less saturated fat, regular movement and weight loss usually move this the most. Discuss with your doctor whether extra support makes sense.

## What this connects

- [hsCRP](https://synapse-lifestyle.com/en/reference-guide/biomarkers/hs-crp)
- [LDL cholesterol](https://synapse-lifestyle.com/en/reference-guide/biomarkers/ldl-cholesterol)
- [Lp(a)](https://synapse-lifestyle.com/en/reference-guide/biomarkers/lipoprotein-a)
- [Triglycerides](https://synapse-lifestyle.com/en/reference-guide/biomarkers/triglycerides)

Developed and reviewed with the Synapse [medical advisory board](https://synapse-lifestyle.com/en/advisory-board).

## References

1. De Oliveira-Gomes, D. et al. Apolipoprotein B: Bridging the Gap Between Evidence and Clinical Practice. Circulation 150, 62–79 (2024). https://doi.org/10.1161/CIRCULATIONAHA.124.068885
2. Richardson, T. G. et al. Evaluating the relationship between circulating lipoprotein lipids and apolipoproteins with risk of coronary heart disease: A multivariable Mendelian randomisation analysis. PLoS Med 17, e1003062 (2020). https://doi.org/10.1371/journal.pmed.1003062
3. Johannesen, C. D. L., Mortensen, M. B., Langsted, A. & Nordestgaard, B. G. Apolipoprotein B and Non-HDL Cholesterol Better Reflect Residual Risk Than LDL Cholesterol in Statin-Treated Patients. J Am Coll Cardiol 77, 1439–1450 (2021). https://doi.org/10.1016/j.jacc.2021.01.027

- [Read more in the reference guide](https://synapse-lifestyle.com/en/reference-guide/heart#Consequence-CSCholesterol-FApoB)
- [All biomarkers in the guide](https://synapse-lifestyle.com/en/reference-guide#biomarkers)

The colour zones are personal: they depend on age, sex, risk and history, and appear in the patient's own report.

Insights to discuss with the patient, not a diagnostic instrument.