ApoB vs. LDL: the number your standard lipid panel leaves out

A standard lipid panel reports LDL cholesterol: the amount of cholesterol inside LDL particles. But plaque forms when particles slip into the artery wall, and the number of particles can differ a lot between two people with the same LDL value. People with insulin resistance, high triglycerides or type 2 diabetes often carry many small particles. Their LDL looks acceptable; their risk is not.

Every particle that can cause plaque — LDL, VLDL, IDL and lipoprotein(a) — carries exactly one apolipoprotein B molecule. Measuring ApoB therefore counts the harmful particles directly. Large genetic and observational studies show that ApoB tracks cardiovascular risk at least as well as LDL, and better when the two disagree.

European guidelines recommend ApoB as a preferred measure, especially for people with diabetes, obesity or high triglycerides. U.S. guidelines list an elevated ApoB as a risk-enhancing factor that can tip the decision toward treatment. In practice, many preventive cardiologists in the U.S. now order it routinely.

Targets depend on your overall risk, so treat these only as orientation:

• Below about 90 mg/dL: commonly cited for people at average risk
• Below about 80 mg/dL: often used at higher risk
• Below about 65 mg/dL: frequently used in very high risk or established heart disease
• 130 mg/dL and above: considered a risk-enhancing factor in U.S. guidance

Your physician sets the target that fits you.

Lp(a) is largely inherited and barely changes with diet or exercise. Roughly one in five people has elevated levels, which raises the risk of heart attack and aortic valve disease. Many experts recommend measuring it at least once in a lifetime. If it is high, the response is to treat every other risk factor more strictly, and to tell your relatives.

ApoB and Lp(a) are simple blood tests from the same draw as a lipid panel. Ask your physician to add them. Cash prices at U.S. labs are often modest, though they vary. Longevity clinics usually include both in their baseline panel.