What the 2026 guideline says about ApoB
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On March 13, 2026, the American College of Cardiology, the American Heart Association and nine other groups published a new US cholesterol guideline, the first since 2018. It lowered the ApoB line that counts as a risk enhancer from 130 to 120 mg/dL, called 140 or more severe high cholesterol, and said measuring ApoB is reasonable for people on treatment once their LDL goal is met. In April a computer model from Northwestern University found that treating to an ApoB goal could prevent more heart attacks and strokes than treating to an LDL goal.
What we’d do
If you’ve never had an ApoB test, ask for one with your next cholesterol panel. If you take a statin and your LDL is at its goal, ask whether your ApoB is at goal too, since that’s the case where the new guideline’s advice is strongest (class 2a). Hold your result against your goal, and against 120 and 140 at any risk. Bring any question about your medicine to the person who prescribes it.
Why the headlines confused people
In April the stories ran with lines like Northwestern’s own, “Little-used cholesterol test could prevent more heart attacks, strokes”. It’s easy to read that as saying the test your doctor uses is wrong, and that isn’t what the study or the guideline says. The guideline still sets its goals on LDL and non-HDL cholesterol, and for most people LDL and ApoB agree. What changed is when ApoB gets measured and which ApoB numbers count, so the test now has a clear job in the cases where the two disagree.
What the guideline says about ApoB
The guideline’s text puts ApoB in these places. The class tells you how strong the advice is. Class 1 means it’s recommended, 2a that it’s reasonable, and 2b that it may be reasonable.
| Where | What it says |
|---|---|
| On treatment, at goal | In adults on cholesterol-lowering medicine, especially with heart disease, type 2 diabetes, kidney and metabolic disease or high triglycerides, measuring ApoB is reasonable to decide on more treatment once the LDL or non-HDL goal is met (class 2a, listed as new) |
| Before treatment | Measuring ApoB may be reasonable to sharpen a risk estimate, help decide whether to start treatment, and spot inherited cholesterol problems (class 2b) |
| Risk enhancers | An ApoB of 120 mg/dL or more is on the list, beside an LDL that stays at 160 to 189 and a non-HDL of 190 to 219 |
| Severe high cholesterol | An ApoB of 140 or more, like an LDL of 190 or more, marks “a population at high lifetime ASCVD risk” |
| High triglycerides | At 150 mg/dL or more, non-HDL or ApoB is preferred over LDL to guide decisions (class 2a) |
| Heart disease with severe high cholesterol | Once the LDL and non-HDL goals are met, it may be reasonable to check ApoB with a goal of under 55 |
| A calcium score of 1 to 99 | A goal of LDL under 100 is written with ApoB under 100 beside it |
| Young adults | ApoB rises about 0.5 mg/dL a year in young adulthood, and that normal rise “should not be perceived as optimal” |
| The test | “ApoB measurement is standardized and unaffected by fasting status” |
| Particle tests | Most results from advanced particle tests don’t change care beyond a standard panel with ApoB or Lp(a) |
What moved since 2018
The 2018 US guideline listed an ApoB of 130 or more as a risk enhancer, said it matched an LDL of about 160, and pointed to measuring it mainly when triglycerides were 200 or more. The 2026 guideline brought that line down to 120. It put an ApoB of 140 beside an LDL of 190 as the line for severe high cholesterol, where the 2018 guideline used LDL alone. And it added a section on when to measure ApoB, which it lists among its new recommendations. It also brought back number goals for LDL and non-HDL, and asked every adult to get an Lp(a) test at least once, both of which cholesterol.guide covers in What changed in the 2026 guideline.
The guideline gives its reason in plain terms. ApoB “directly measures atherogenic particle number, with 1 molecule per LDL, very-low-density lipoprotein (VLDL), and Lp(a) particle”, and when ApoB and LDL disagree, it “predicts ASCVD risk more accurately”. One of the studies behind that is Marston’s, where only ApoB stayed tied to heart attacks once triglycerides and non-HDL were in the same model, in 429,959 people. Why heart attacks follow the count has the rest.
Like a scale and a headcount
Think of a delivery company that has always weighed its trucks’ cargo to plan the roads. The new rule says to keep weighing, and to count the trucks as well when the weight looks off: when triglycerides are high, with diabetes, or once a medicine has already brought the weight down. LDL weighs the cholesterol and ApoB counts the particles carrying it.
Where the ApoB goals come from
The guideline draws its goals in a figure, and its text gives ApoB numbers only at 55, 100, 120 and 140. The ApoB ladder most people use comes from the National Lipid Association, one of the 11 groups that wrote the guideline. Its 2024 table matches ApoB to the same LDL goals: under 90 for LDL under 100, under 70 for LDL under 70, and under 60 for LDL under 55.
- Under 60 very high risk
- Under 70 high risk
- Under 90 borderline or intermediate risk
- 120 raises risk
- 140 severe
mg/dL over g/L. Rungs from the National Lipid Association (2024), matched to the 2026 US guideline's LDL goals. Ticks from the 2026 guideline.
What should my ApoB be? has the ladder with your risk, and Is my ApoB high? puts your number on it.
The Northwestern study, April 2026
On April 8, 2026, Northwestern University announced a study in JAMA led by Ciaran Kohli-Lynch, an assistant professor of preventive medicine. His team built a computer model of 250,000 US adults who were eligible for a statin and had no heart disease. They compared three ways of treating them: to an LDL under 100, a non-HDL under 118, or an ApoB under 78.7 mg/dL. Treating to the ApoB goal “outperformed the other two strategies”, the release said, preventing more heart attacks and strokes at “a cost that represents good value for U.S. healthcare payers”.
It’s a model, so it shows what should happen if the studies it’s built on are right. Nobody has yet run the trial that would settle it, with one group treated to an ApoB goal and another to an LDL goal and heart attacks counted. The model’s 78.7 isn’t a guideline number either. The release also gave the plain reason the test is rare: it “typically requires an additional blood test besides the standard cholesterol panel”.
What didn’t change
LDL and non-HDL are still the numbers the guideline sets goals for, and the goals still follow your risk, which your doctor works out with a calculator called PREVENT. Healthy habits come first for everyone, and supplements sold to lower cholesterol are not recommended. Nothing in the guideline tells anyone to stop a medicine, and if you take one, your prescriber decides any change. ApoB on a statin has the questions to bring, and Who should get an ApoB test? has the groups the guideline names.
6 sources
- Blumenthal RS, Morris PB, Gaudino M and others, 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of dyslipidemia, JACC and Circulation, 13 March 2026doi.org
- The same guideline, full text, Circulation, 2026api.iscpcardio.org
- Grundy SM, Stone NJ and others, 2018 AHA/ACC guideline on the management of blood cholesterol, Circulation, 2019pmc.ncbi.nlm.nih.gov
- 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, 8 April 2026news.northwestern.edu
- Marston NA and others, Association of apolipoprotein B-containing lipoproteins and risk of myocardial infarction in individuals with and without atherosclerosis, JAMA Cardiology, 2022pmc.ncbi.nlm.nih.gov
