For decades, LDL cholesterol has been one of the best-known numbers in cardiovascular medicine. In February 2026, a Swedish twin study added a modern layer to that story.
Researchers analysed 173 blood-based metabolomic biomarkers in 11,217 twins and linked them to later cardiovascular diagnoses. For myocardial infarction, the signals that survived the strictest comparison converged on ApoB-related lipoprotein biology.
Quick answer
Does the Swedish twin study prove ApoB is more important than LDL?
No. It strongly highlights ApoB-related biology in this cohort, but it was an observational metabolomics study, not a randomized head-to-head test of ApoB versus LDL-based care. Its value is the convergence of future heart-attack signals even after within-twin-pair analysis.
Key takeaways
- The study included 11,217 twins aged 47–94 from the Swedish Twin Registry.
- Researchers measured 173 NMR metabolomic biomarkers and used nationwide registers for incident cardiovascular diagnoses.
- Fifty-one biomarkers were associated with later myocardial infarction after multiple-testing correction in both individual and twin-pair analyses.
- LASSO analysis highlighted four biomarkers, all related to ApoB lipoprotein biology.
- The study supports ApoB as an important research signal, but does not prove that one biomarker alone causes or predicts every heart attack.
What ApoB measures — in plain language
Apolipoprotein B is a structural protein carried by atherogenic lipoprotein particles such as LDL, IDL and VLDL remnants. Each of these particles carries one ApoB molecule, so ApoB can act as a proxy for the number of circulating atherogenic particles.
LDL cholesterol, by contrast, describes how much cholesterol is carried inside LDL particles. Particle number and cholesterol content often track together, but not always. That is why the two measurements can provide overlapping rather than identical information.
The 2026 study: from blood sample to future diagnosis
The researchers studied twins aged 47–94, with a mean age of 65, and included only cardiovascular diagnoses that occurred after the blood sample.
They first analysed associations at the individual level and then within twin pairs. Within-pair analyses are valuable because twins share family background and, for monozygotic pairs, essentially all inherited DNA.
Why the myocardial-infarction result stood out
Fifty-one biomarkers remained associated with myocardial infarction after correction for multiple testing in both individual and twin-pair analyses, and all had hazard ratios above one.
When LASSO regression was used to reduce that set, four biomarkers remained. All were related to ApoB-containing lipoprotein biology. The ApoB/ApoA1 balance was among the strongest signals discussed by the investigators.
Strong signal does not mean simple causality
The study did not assign twins to different lipid levels. It observed biomarkers and followed diagnoses through registers. Residual confounding, medication, metabolic health and other factors can still matter.
The conclusion should therefore be “ApoB biology stood out strongly in this twin-based metabolomics analysis”, not “ApoB alone causes all heart attacks” or “LDL no longer matters”.
TwinPare perspective: this is what modern twin research can become
Classical twin studies ask how much traits cluster with genetic similarity. Modern twin research can go further by combining the co-twin design with metabolomics, epigenetics and national health registers.
That combination is especially relevant to TwinPare’s research mission: use similarities to reduce noise, then study the biological differences that may help explain why one person develops disease and another does not.
Source notes
The source has been verified and editorially reviewed for this article. The limitations below show which level of conclusion the sources support.
- [skovgaard-2026-apob] A blood-based metabolomics study of cardiovascular diseases in Swedish twins reveals apolipoprotein B biology as important for myocardial infarction Asmus C Skovgaard et al.. GeroScience, 2026. Evidence type: Prospective register-linked metabolomics study of 11,217 Swedish twins with 173 NMR biomarkers Limitation: Fifty-one biomarkers associated with incident myocardial infarction in both individual- and twin-pair analyses; LASSO highlighted four ApoB-related biomarkers. The observational design does not prove that a single biomarker causes an event or that ApoB replaces all other risk assessment. PubMed DOI
Editorial source review
This section shows how the article's key factual claims are linked to the source.
Phrasings that require caution
- Do not state that this observational study proves ApoB causes myocardial infarction.
- Do not claim ApoB universally replaces LDL-C or clinical risk assessment.
- Blood-lipid interpretation and treatment decisions require medical context.
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