What Is ApoB, and Is It Better Than LDL Cholesterol?

Apolipoprotein B (ApoB) is a protein carried once by every particle that can lodge in artery walls and cause atherosclerosis: LDL, VLDL, and their remnants, and lipoprotein(a). So measuring ApoB counts those particles directly. LDL cholesterol measures how much cholesterol they carry instead. Usually the two tell the same story, but when they disagree, ApoB tends to be the better guide to risk.

This article is general information, not medical advice.

Particles Versus Cholesterol

Atherosclerosis starts when particles carrying cholesterol enter the artery wall and get stuck, and the number of particles drives how often that happens. Each atherogenic particle has one ApoB molecule. But particles carry different amounts of cholesterol: someone with many small, cholesterol-poor particles, common with high triglycerides, diabetes, or obesity, can have a “normal” LDL cholesterol and a high ApoB. In their 2019 review, Sniderman and colleagues argued that ApoB, as the particle count, is the more accurate marker of risk.

What Guidelines Say

• US (2018 AHA/ACC cholesterol guideline, Grundy and colleagues). ApoB isn’t required, but an ApoB of 130 mg/dL or more counts as a risk-enhancing factor, and measuring it is reasonable when triglycerides are 200 mg/dL or more.
• Europe (2019 ESC/EAS dyslipidaemia guidelines, Mach and colleagues). ApoB analysis is recommended for risk assessment, particularly in people with high triglycerides, diabetes, obesity, or very low LDL cholesterol, and can be used instead of LDL cholesterol. It sets ApoB targets alongside LDL targets.

Non-HDL Cholesterol

Non-HDL cholesterol is total cholesterol minus HDL cholesterol: all the cholesterol in atherogenic particles. It needs no extra test or equation, works without fasting, and tracks ApoB more closely than LDL cholesterol does. Both guidelines use it as a secondary target. If ApoB isn’t available, it’s the next best thing.

How to Read Yours

Read it with your lab’s range and your doctor, alongside your other risk factors. A high ApoB with a normal LDL cholesterol is the case worth asking about. ApoB is measured directly, so it doesn’t depend on triglycerides or an equation; see Why Does Your LDL Cholesterol Depend on the Equation?

Following It in Kaizora

Apolipoprotein B and Non-HDL Cholesterol are lab results on Labs, logged with their time, laboratory, and printed range. A draw’s results share their time and lab, so ApoB sits beside the LDL cholesterol from the same blood. The Kaizora Longevity Score uses non-HDL cholesterol, scored by the American Heart Association’s Life’s Essential 8, in its metabolic labs component.

The Short Version

• ApoB counts the particles that cause atherosclerosis; LDL cholesterol measures their cholesterol.
• When they disagree, ApoB is usually the better guide to risk.
• An ApoB of 130 mg/dL or more is a risk enhancer in the US guideline; Europe recommends it particularly with high triglycerides, diabetes, or obesity.
• Non-HDL cholesterol is a simple, close alternative.

Sources

• Sniderman AD et al., “Apolipoprotein B particles and cardiovascular disease: a narrative review,” JAMA Cardiology 4, no. 12 (2019): 1287. doi:10.1001/jamacardio.2019.3780
• Grundy SM et al., “2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol,” Circulation 139, no. 25 (2019). doi:10.1161/CIR.0000000000000625
• Mach F et al., “2019 ESC/EAS guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk,” European Heart Journal 41, no. 1 (2020): 111–188. doi:10.1093/eurheartj/ehz455