Patients with both depression and pre-diabetes are at higher risk of developing dementia in later life, compared to those with neither condition, according to UK researchers.
A landmark study has suggested that patients at high risk of developing type 2 diabetes, and who also have depression, are nearly three times more likely to develop dementia in later life.
“There is growing evidence linking diabetes and high blood glucose levels to dementia”
The authors noted that previous studies had suggested that diabetes and depression could be linked to a higher risk of dementia. But they said their study was the first time that it had been investigated whether this risk was increased if a person had both pre-diabetes and depression.
The researchers followed 3,458 adults over the age of 50 from the English Longitudinal Study of Ageing for up to 10 years. They split the participants into six groups based on the presence of diabetes, pre-diabetes and/or depression.
The findings, presented today at the annual Diabetes UK Professional Conference in London, confirmed that depression and diabetes were risk factors for dementia, said the researchers.
However, they said the findings also suggested that those with both depression and pre-diabetes were nearly three times more likely to develop the serious progressive neurological disorder.
Lead study Dr Kimberley Smith said: “There is a lot of evidence that the co-occurrence of depression and diabetes is linked with the development of serious complications of diabetes such as dementia.
“Our work extends this by also showing that prediabetes and depression might also be linked with a greater risk of developing dementia,” said Dr Smith from the University of Surrey.
“These findings are further evidence of the importance of poor mental health”
She said that, while based on a “relatively small number” of people, the new findings were further evidence of the “importance of poor mental health in people with prediabetes and diabetes”.
“These preliminary findings will be explored in our future work so we can determine why this association might exist,” she noted.
Dr Elizabeth Robertson, director of research at Diabetes UK, added: “There is growing evidence linking diabetes and high blood glucose levels to dementia.
“These new findings suggest an earlier correlation with people at high risk of developing type 2 diabetes who also have depression,” she said.
She highlighted that more research was now needed to understand “why this potential connection could exist” and what could be done to reduce the risk of dementia in “as many people as possible”.