New study explains the link between long-term diabetes and vascular damage

The longer a person has type 2 diabetes, the greater the risk of cardiovascular disease. A new study from Karolinska Institutet, published in the journal Diabetes, shows that changes in red blood cells may be an important explanation, and identifies a specific molecule as a possible biomarker.

People with type 2 diabetes are at increased risk of heart attack and stroke, and the risk increases the longer they have lived with the disease. Previous research has shown that red blood cells can affect blood vessel function in diabetes. Now, a new study shows that the duration of the disease plays a decisive role in when and how these changes occur—and that long-term type 2 diabetes can make red blood cells directly harmful to blood vessels.

The researchers studied both animals and patients with type 2 diabetes. Red blood cells from mice and patients with long-term diabetes had a harmful effect on blood vessel function. No such effect was seen in newly diagnosed individuals, but after seven years of follow-up, their blood cells had developed the same harmful properties. When the researchers restored the levels of microRNA-210 in the red blood cells, vascular function improved.

“What really stands out in our study is that it is not only the presence of type 2 diabetes that matters, but how long you have had the disease. It is only after several years that red blood cells develop a harmful effect on blood vessels,” says Zhichao Zhou, associate professor at the Department of Medicine, Solna, Karolinska Institutet, and lead author of the study.

The study points to microRNA-210 in red blood cells as a possible biomarker for early detection of the risk of cardiovascular complications. Researchers are now working to investigate whether this can be used in larger population studies.

“If we can identify which patients are at greatest risk before vascular damage has already occurred, we can also become better at preventing complications,” says Eftychia Kontidou, doctoral student from the same group and the first author of the study.

The study is funded by, among others, the EFSD/Novo Nordisk Foundation Future Leaders Award, the Swedish Heart-Lung Foundation, and the Swedish Research Council. The researchers report no conflicts of interest.

Publikation: ”Long Duration of Type 2 Diabetes Drives Erythrocyte-Induced Vascular Endothelial Dysfunction: A Link to microRNA-210-3p”, Eftychia Kontidou, Aida Collado, Rawan Humoud, Kesavan Manickam, John Tengbom, Tong Jiao, Michael Alvarsson, Jiangning Yang, Linda Mellbin, Ali Mahdi, John Pernow, Zhichao Zhou, Diabetes, online January 9, 2026, doi: 10.2337/db25-0463