# LDL cholesterol

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

Unit: mg/dL

## What is LDL cholesterol?

LDL is a particle that carries cholesterol through your blood to your tissues. Your body needs cholesterol as a building block, but too much LDL can slowly build up in the walls of your blood vessels. That is why LDL is often called the “bad” cholesterol.

## Clinical frame

**LDL cholesterol is a causal cause of atherosclerosis**, not merely a risk marker. Genetic studies, cohorts and intervention trials show a dose- and duration-dependent relationship: the more LDL enters and is retained by the vessel wall over the years, the greater the plaque burden and the risk of a cardiovascular event [1].

That is why **cumulative exposure** matters more than a single snapshot. Every 1 mmol/L (about 39 mg/dL) reduction lowers the risk by roughly one fifth, regardless of the agent used, and the benefit grows with every year that LDL stays lower [1] [3].

The ESC/EAS guideline uses no universal threshold but **targets per risk category**, stricter as the total cardiovascular risk rises [2]. LDL underestimates the risk when many small, cholesterol-poor particles circulate. ApoB and non-HDL cholesterol capture that discordance and are therefore weighed alongside it [2].

## What moves this value?

A lot of saturated fat (fatty meat, full-fat dairy, pastries), few fibres and hereditary predisposition play the biggest role. A slow-working thyroid can also raise LDL.

What helps most: more soluble fibre (oats, legumes, vegetables and fruit), less saturated fat and regular exercise. If your value does not respond enough to that, it is something to look at together with your doctor.

## What this connects

- [ApoB](https://synapse-lifestyle.com/en/reference-guide/biomarkers/apob)
- [HDL cholesterol](https://synapse-lifestyle.com/en/reference-guide/biomarkers/hdl-cholesterol)
- [Cholesterol](https://synapse-lifestyle.com/en/reference-guide/biomarkers/total-cholesterol)

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

## References

1. Ference, B. A. et al. Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel. Eur Heart J 38, 2459–2472 (2017). https://doi.org/10.1093/eurheartj/ehx144
2. Mach, F. et al. 2025 Focused Update of the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J 46, 4359–4378 (2025). https://doi.org/10.1093/eurheartj/ehaf190
3. Ference, B. A., Braunwald, E. & Catapano, A. L. The LDL cumulative exposure hypothesis: evidence and practical applications. Nat Rev Cardiol 21, 701–716 (2024). https://doi.org/10.1038/s41569-024-01039-5

- [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.