The researchers conducted a study of more than 900 diabetes sufferers over the age of 60 and discovered that brain function slowed in participants with higher levels of the stress hormone cortisol.
Participants’ mental abilities were measured with a range of tests, including memory and information processing.
The project, which was funded by the Medical Research Council, will now progress to examine other factors which may impact on memory problems.
Responding to the findings, a spokeswoman for the Insulin Dependent Diabetes Trust said the results are inconclusive.
She added: “Diabetes type 1 and type 2 is too complicated an issue and can be affected by many different factors – including the different types of insulin … which substantially affect patients’ stress levels.”