Adult-onset type 1 diabetes increases risk of CV disease and death, reveals research

A new study in the European Heart Journal shows that people who develop type 1 diabetes in adulthood have an increased risk of cardiovascular disease and death, and that those diagnosed later in life do not have a better prognosis than those diagnosed earlier. The study, conducted by researchers at Karolinska Institutet in Sweden, points to smoking, poor glucose control and obesity as the main risk factors.

Type 1 diabetes used to be called childhood diabetes but can start at any time during life. However, research on adult-onset type 1 diabetes is limited. The researchers behind the current study wanted to investigate the risk of cardiovascular disease and death in this group, particularly for those diagnosed after the age of 40.

The registry-based study identified 10 184 people diagnosed with type 1 diabetes in adulthood between 2001 and 2020 and compared them to 509 172 matched people in the control group.

The study shows that these people with adult-onset type 1 diabetes had a higher risk of cardiovascular disease and death from all causes, including cancer and infections, compared to the control group.

“The main reasons for the poor prognosis are smoking, overweight/obesity and poor glucose control. We found that they were less likely to use assistive devices, such as insulin pumps,” says first author Yuxia Wei, postdoctoral fellow at the Institute of Environmental Medicine, Karolinska Institutet.

The results emphasise the seriousness of type 1 diabetes, even when it starts later in life, the researchers say.

“But we show that the prognosis can be significantly improved by preventing smoking and obesity and improving glucose control, not least in people diagnosed at older ages,” explains senior author Sofia Carlsson, senior lecturer and associate professor at the same department.

The researchers plan to continue investigating adult-onset type 1 diabetes, including risk factors for developing the disease and the prognosis of other outcomes, such as microvascular complications. Optimal treatment in adult-onset type 1 diabetes, including the effect of pump use and other advanced technologies, also needs to be explored.

“We hope to shed light on these issues in the coming years,” concludes Sofia Carlsson.

Reference:

Yuxia Wei, Tomas Andersson, Tiinamaija Tuomi, Thomas Nyström, Sofia Carlsson, Adult-onset type 1 diabetes: predictors of major cardiovascular events and mortality, European Heart Journal, 2025;, ehaf304, https://doi.org/10.1093/eurheartj/ehaf304.