Researchers found they are 42 percent more likely to suffer from cognitive impairment and have a 54 percent higher risk of developing full-blown dementia. Diabetes affects as many as seven million people in the UK. The study saw 500,000 British adults with an average age of 58 given blood and memory tests.
Prediabetes was found to be associated with a higher risk of vascular dementia – a common form of the disease caused by reduced blood flow to the brain.
People with full diabetes were three times more likely to develop vascular dementia than those with normal blood sugar levels. They were also more likely to develop Alzheimer’s.
Prediabetes was also linked to a smaller “hippocampus” – the part of the brain associated with learning and memory.
Dr Victoria Garfield, of University College London, said: “Our research shows a possible link between higher blood sugar levels – a state often described as ‘prediabetes’ – and higher risks of cognitive decline and vascular dementia. Previous research has found a link between poorer cognitive outcomes and diabetes.
“But our study is the first to investigate how having blood sugar levels that are relatively high – but do not constitute diabetes – may affect brain health.”
Professor Nishi Chaturvedi, also of UCL, added: “In this relatively young age group, the risks of dementia are very low.
“Seeing whether these effects persist as people get older, and where absolute rates of disease get higher, will be important.”
She said if the results – published in the journal Diabetes, Obesity and Metabolism – are confirmed it could make the case for early intervention.
Prof Chaturvedi added: “They open up questions about the benefits of screening for diabetes in the general population.”