Stress raises the risk of memory loss and cognitive decline among older people with diabetes, research suggests.
University researchers studied more than 900 men and women aged between 60 and 75 with type-2 diabetes.
Scientists evaluated mental abilities with a range of tests, including memory function and how quickly participants processed information.
They compared this with general intelligence levels, using vocabulary tests, to work out whether brain function in participants had diminished over time.
They found that brain function slowed in participants with higher levels of the stress hormone cortisol.
This study shows that older people with diabetes who have higher levels of stress hormones in their blood are more likely to have experienced cognitive decline. It may be that by regulating cortisol levels, we could help improve cognitive decline in patients with type-2 diabetes.
The study, published by Diabetes Care, took into account factors such as education, cardiovascular disease, smoking and mood.
It is part of the Edinburgh Type-2 Diabetes Study set up four years ago to better understand why people with diabetes may have memory problems.
Researchers are now inviting people who enrolled when the study was set up to take part in follow-up research to repeat the memory tests.
Type-2 diabetes tends to be more common after the age of 40.
It is linked to problems with memory, but the reason behind this is unclear.
The scientists, who have been funded by the Medical Research Council, will now look at other factors which may also impact on memory problems.