Diabetes could lead to reduced brain power

Published on Thursday 4 March 2010 21:39

DIABETIC patients with sight problems could suffer from poorer memory and weakened brain power, Scottish research suggests.

Diabetic retinopathy is the leading cause of blindness in the UK's working-age population.

Now a study by Edinburgh University has found that the condition could have an effect on memory and brain power in those with type 2 diabetes.

The researchers looked at 1,066 people with type 2 diabetes aged between 60 and 75.

Participants in the study completed seven tests focusing on memory, logic and concentration to establish their level of brain function.

Those with retinopathy had worse scores on most of the individual tests, as well as on general cognitive ability, compared with those without the condition.

Jie Ding, from Edinburgh University, who helped lead the research, said: "These findings suggest that the severity of diabetic retinopathy is independently associated with cognitive dysfunction in people with type 2 diabetes aged 60 to 75."

She said retinopathy may cause microvascular disease – damage to the smallest blood vessels – in the brain, leading to a drop in mental ability. It could also be that poorer cognitive ability makes diabetes management more difficult, and in turn promotes the development of cerebral micro-vascular disease.

But another unknown factor could be causing the link, the researcher said.

Dr Iain Frame, director of research at Diabetes UK, said retinopathy was an indicator of cerebral microvascular disease, which is when the small blood vessels in the brain are narrowed or blocked, leading to a reduction in blood supply to the brain tissues.

Dr Frame added: "There is already evidence to suggest that cerebral microvascular disease and type 2 diabetes may exacerbate the effects of ageing on cognitive function.

"This study adds to this body of research, as it suggests that diabetic retinopathy is linked to an estimated life-time cognitive decline in older people with type 2 diabetes.

"Cognitive decline is the decline of brain functions such as memory and planning.

"If anyone with diabetes is concerned about their health they should consult their GP or diabetes healthcare professional."

The study, presented at Diabetes UK's Annual Professional Conference in Liverpool, found that participants with moderate to severe retinopathy performed worse in the non-verbal memory, mental flexibility and processing speed tests compared to those with mild or no retinopathy.

It also suggested that the male participants with moderate to severe retinopathy might be more prone to cognitive decline in old age.