Oxidized LDL (oxLDL)

LDL particles carry cholesterol to the tissues. When such a particle ends up in the blood vessel wall, it can be damaged by oxygen radicals; this is called oxidation. Oxidized LDL (oxLDL) triggers an inflammatory reaction in the vessel wall and so plays a role in the development of hardening of the arteries (atherosclerosis). The test uses an antibody assay to measure how much of this damaged LDL circulates in the blood; that is only a small part of the total LDL.

• Presence of damaged LDL, a marker of the inflammatory process in hardening of the arteries
• Association with overweight, type 2 diabetes and metabolic syndrome, without the test being able to diagnose those conditions

An abnormal value does not in itself lead to further tests. If needed, the GP assesses the ordinary lipid profile and the overall risk profile with SCORE2 and acts on that with lifestyle advice or, at high risk, cholesterol-lowering treatment.

According to the multidisciplinary guideline on cardiovascular risk management, biomarkers in blood or urine, such as this one, add little to the estimate of the risk of cardiovascular disease, also in people with known cardiovascular disease; the Dutch GP guideline (NHG) estimates the risk with SCORE2 based on age, sex, smoking, blood pressure and non-HDL cholesterol. In the scientific literature, different antibody assays are used for oxLDL, none of which has been approved for routine clinical use. A result is therefore mainly a research figure, not a measure on which treatment decisions are based.

• There is no standardized measurement method; different laboratories and test kits give different results that cannot be compared.
• There are no Dutch reference values; the limits on a result come from the manufacturer of the test.
• The value is closely linked to ordinary LDL cholesterol; apart from that, its meaning is unclear.
• Inflammation, an infection, smoking or an acute illness can affect the value, without it being clear by how much.

There are no Dutch figures on oxidized LDL, because the test is not done as standard. It is known how common raised cholesterol is: in 2024, more than 1.6 million people in the Netherlands were known to their GP with a lipid metabolism disorder, about 9 in 100 inhabitants.

The result says little about your own risk, also with risk factors or known cardiovascular disease. If you want your risk of cardiovascular disease estimated, the ordinary lipid profile (total cholesterol, HDL, LDL, non-HDL and triglycerides), blood pressure, smoking status and blood sugar are more useful. In practice, the result of this test does not change the GP's advice.

• Because there is no standardized method and there are no Dutch cut-off values, a 'raised' result can cause unnecessary worry and unnecessary further tests.
• The test can give the impression that it measures an extra or better heart risk than ordinary cholesterol testing, while there is no evidence for that.

• FMS Richtlijnendatabase: CVRM, module Andere voorspellers van het risico op hart- en vaatziekten
• Trpkovic A e.a. Oxidized low-density lipoprotein as a biomarker of cardiovascular diseases. Crit Rev Clin Lab Sci 2015 (PubMed-samenvatting)
• NVKC, allesovertesten.nl: LDL
• NHG-Standaard Cardiovasculair risicomanagement (M84)
• VZinfo (RIVM): Cholesterol, op basis van Nivel Zorgregistraties Eerste Lijn 2024