Who should get an ApoB test?
The 2026 US guideline says ApoB helps most once you’re on a cholesterol medicine and at your LDL goal, above all with triglycerides over 200, diabetes, or an LDL under 70. For people not on treatment, it says testing “may be reasonable” to sharpen their risk and help decide whether to start. We’d go further and test it once in any adult who’s checking their heart risk.
What we’d do
Get ApoB once, with your next cholesterol panel. It’s one more line on the same blood draw, and you don’t have to fast. Make it a regular test if your triglycerides are high, you have diabetes or extra weight, you’re on a statin, or a parent or sibling had heart disease young. If your first ApoB agrees with your LDL and you’re at goal, your regular panel can carry most of the load after that.
What the guideline says
| Who | What the guideline says | How strongly |
|---|---|---|
| On a cholesterol medicine, especially with heart disease, kidney and metabolic disease, type 2 diabetes or high triglycerides | Measuring ApoB is “reasonable” once LDL and non-HDL goals are met, to decide whether to do more | Class 2a, its second-strongest |
| Not on a cholesterol medicine | Measuring ApoB “may be reasonable” to sharpen risk, help decide on starting treatment and find inherited lipid disorders | Class 2b |
| Triglycerides of 150 or more | Non-HDL or ApoB is preferred over LDL for decisions | Class 2a |
Its summary of top messages says ApoB testing “can be useful” once LDL and non-HDL goals are met, particularly with triglycerides over 200 mg/dL, diabetes, or an LDL that treatment has brought under 70.
Why those people
Their particles tend to carry less cholesterol each. With diabetes, kidney and metabolic disease and high triglycerides, the guideline says LDL can look at goal while ApoB stays high. Statins add to it, since across 11 trials they cut LDL 42% on average and ApoB only 33%. When LDL is low, the old LDL formula is also at its least reliable.
It’s like a fuel gauge that works fine on a full tank and gets shaky near empty. The further your numbers are from typical, the more a direct count helps.
The case for everyone
The guideline stops at “may be reasonable” for people not on treatment. We’d test anyway, for three reasons. ApoB predicts heart disease better than LDL when the two disagree, and you can’t know if yours disagree until you’ve measured it. Young adults with a high ApoB and a low LDL had 1.55 times the odds of calcium in their heart arteries 25 years later, in the CARDIA study of 2,794 people. And a Northwestern computer model of 250,000 US adults eligible for statins, published in JAMA in 2026, found that guiding treatment by ApoB under 78.7 beat guiding it by LDL or non-HDL. That was a simulation, and no trial has tested it yet.
The National Lipid Association adds families. When an inherited lipid disorder turns up in someone, ApoB testing helps screen their relatives.
What’s stopping people
Mostly it’s habit and insurance. The NLA says “the cost of performing the test is low”, but it often isn’t available at local or hospital labs, and insurers sometimes deny it or ask for prior approval. Is ApoB part of a standard cholesterol test? covers how to ask for it, and Where can I get an ApoB test? the options.
5 sources
- Blumenthal RS, Morris PB, Gaudino M and others, 2026 ACC/AHA guideline on the management of dyslipidemia, JACC, 2026doi.org
- The same guideline, full text, Circulation, 2026api.iscpcardio.org
- Soffer DE, Marston NA, Maki KC and others, Role of apolipoprotein B in the clinical management of cardiovascular risk in adults: an Expert Clinical Consensus from the National Lipid Association, Journal of Clinical Lipidology, 2024pmc.ncbi.nlm.nih.gov
- Northwestern University, Little-used cholesterol test could prevent more heart attacks, strokes, news release on a JAMA modeling study, April 2026news.northwestern.edu
- Wilkins JT and others, Discordance between apolipoprotein B and LDL-cholesterol in young adults predicts coronary artery calcification: the CARDIA study, Journal of the American College of Cardiology, 2016pubmed.ncbi.nlm.nih.gov
