- The longer someone lives with type 2 diabetes, the higher their cardiovascular risk – and red blood cells may be part of why
- In long-standing diabetes, red blood cells can disrupt the lining of blood vessels, while this effect is not seen soon after diagnosis
- A small molecule inside red blood cells, microRNA-210, could one day help flag rising cardiovascular risk earlier
Type 2 diabetes is closely tied to heart attacks and strokes, and the risk does not stay static – it rises year by year.
A study from Karolinska Institutet adds an important detail to that picture: it is not just having type 2 diabetes that matters, it is how long you have had it.
Researchers focused on red blood cells, which do far more than transport oxygen. In diabetes, they have already been implicated in changes to how blood vessels behave.
What this work shows is a timing effect – red blood cells appear to become more harmful only after several years of living with the condition.
To tease this apart, the team examined both animal models and people with type 2 diabetes.
Red blood cells taken from mice and from patients who had lived with type 2 diabetes for a long time interfered with normal blood vessel function.
By contrast, red blood cells from people newly diagnosed did not show the same damaging behaviour.
The study also tracked a group of patients over time. At the start, their red blood cells did not appear to harm blood vessels.
After seven years of follow-up, that changed – their red blood cells had developed the same disruptive properties seen in long-duration diabetes.
That shift suggests a gradual biological change that builds with time rather than appearing immediately.
A key suspect is a small regulatory molecule inside cells called microRNA-210.
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When researchers restored microRNA-210 levels in red blood cells, blood vessel function improved in their experiments.
That points to a potential mechanism for how red blood cells move from being neutral players to active contributors to vessel dysfunction.
The practical implication is clear: if clinicians could track a marker like microRNA-210 in red blood cells, they might one day be able to spot people whose cardiovascular risk is starting to climb before the damage is entrenched.
The researchers are now looking at whether this approach holds up in larger population studies, where it could form the basis of a future biomarker test.
