Older people with type 2 diabetes may struggle more with verbal memory than their peers without the disease, a recent study suggests. Researchers followed 705 older adults without dementia for an average of 4.6 years. At the start, participants were between 55 and 90 years old, with an average age around 70, and 348 of them had diabetes.
In people with diabetes, verbal fluency declined slightly over the course of the study, while it improved slightly in participants without diabetes, researchers report in Diabetologia. Diabetes develops when the body can't properly use insulin to convert blood sugar into energy and the condition is associated with obesity and aging. While diabetes has long been linked to cognitive decline and dementia, research to date hasn't offered a clear reason for this connection.
Three times during the study, participants had brain scans to look for any signs of atrophy - tissue shrinkage - and they took cognitive tests involving verbal skills. Although people with diabetes already had more brain atrophy at the start, there was no difference between those with and without diabetes in the rate of brain shrinkage during the study. Atrophy also didn't appear to explain the link between diabetes and cognitive decline.
Still, the results suggest that brain changes associated with diabetes may begin earlier than previously thought, perhaps in middle age, said lead author Michele Callisaya of the University of Tasmania in Hobart, Australia.
For patients, this means it would be a mistake to put off thinking about brain health until they're older or experiencing symptoms of cognitive decline, Callisaya said by email. The diabetics in the study were a bit younger, 68 years old on average, compared with an average of 72 for the participants without diabetes.