High blood sugar levels – a common problem for people with diabetes – ‘reprogramme’ stem cells leading to long-term heart problems and changes in the immune system, according to research.
Scientists at the University of Oxford have found people with diabetes are at risk of atherosclerosis, causing plaque to build up in the arteries, which leads to heart attacks, even when the diabetes is brought under control.
High levels of blood glucose alter stem cells in the bone marrow. The stem cells go on to become white blood cells known as macrophages and where blood sugar levels are high, macrophages become inflamed and contribute to the development of atherosclerotic plaques.
Diabetes affects nearly five million million people in the UK and adults with the condition have double the risk of having a heart attack. The research, which was published in the journal Circulation last week, explains why people with diabetes remain at risk of heart attacks even after their diabetes is brought under control.
In order to investigate the difference in white blood cells, the scientists removed these cells from people with and without type 2 diabetes and grew them in an environment where glucose levels were at regular levels. They found that cells from people who had diabetes showed a strong inflammatory response when compared to cells from people without diabetes.
Professor Robin Choudhury, a Professor of Cardiovascular Medicine at the Radcliffe Department of Medicine, University of Oxford, who led the research said: ‘Our study is the first to show that diabetes causes long-term changes to the immune system, and how this might account for the sustained increase in the risk of a heart attack.’
In addition, the researchers extracted stem cells from the bone marrow of mice with and without diabetes and transplanted them into mice with normal blood sugar levels.
The mice that inherited stem cells from diabetic mice showed high levels of heart disease, indicating the transplanted stem cells ‘remembered’ the high blood sugar environment from the diabetic mice. These mice developed almost double the amount of atherosclerotic plaques despite having normal glucose levels.
Professor Choudhury said: ‘We need to change the way we think about, and treat, diabetes. By focussing too narrowly on managing a person’s blood sugar levels we’re only addressing part of the problem.’
He added: ‘Right now, people with diabetes aren’t receiving effective treatment for their increased risk of heart and circulatory disease. These findings identify new opportunities for preventing and treating the complications of diabetes.’