People who develop diabetes in middle age may be more likely to have smaller brains later in life, warns a new study. Researchers found that people who develop diabetes and high blood pressure between the age of 40 and 64 are more at risk of losing brain volume and suffer problems with memory and thinking skills.
The US study suggests, along with previous research, that people with diabetes may have a greater chance of developing dementia.
Study author Doctor Rosebud Roberts, of the Mayo Clinic, said ‘Potentially, if we can prevent or control diabetes and high blood pressure in middle age, we can prevent or delay the brain damage that occurs decades later and leads to memory and thinking problems and dementia.’
For the study, published online by the journal Neurology (must credit), the thinking and memory skills of more than 1,400 people with an average age of 80 were assessed.
The participants had either no thinking or memory problems or mild memory and thinking problems, known as mild cognitive impairment.
They were given brain scans to look for markers of brain damage that can be a precursor to dementia.
The participants’ medical records were also reviewed to determine whether they had been diagnosed with diabetes or high blood pressure in middle age or later.
For diabetes, 72 people developed it in middle age, 142 in old age and 1,192 did not have diabetes.
For high blood pressure, 449 people developed it in middle age, 448 in old age and 369 did not have it.
Compared to people who did not have diabetes, people who developed diabetes in middle age had total brain volume that was 2.9 per cent smaller on average.
In the hippocampus area of the brain, the volume was four per cent smaller.
They were also twice as likely to have thinking and memory problems.
Compared to people who did not have high blood pressure, people who developed high blood pressure in middle age were twice as likely to have areas of brain damage.
Dr Roberts said ‘People who developed diabetes even in old age were also more likely to have areas of brain damage.
‘Conversely, there were not many effects from high blood pressure that developed in old age.
‘Overall, our findings suggest that the effects of these diseases on the brain take decades to develop and show up as brain damage and lead to symptoms that affect their memory and other thinking skills.
‘In particular, diabetes has adverse effects regardless of the age at which diabetes develops.’
Dr Simon Ridley, head of research at Alzheimer’s Research UK charity, said ‘Previous research has linked type 2 diabetes and high blood pressure to an increased risk of dementia, but the reasons underlying these links are not yet fully understood.
‘It’s not possible to know from this study whether type 2 diabetes or high blood pressure cause dementia, and more research is needed to gain a full understanding of their impact on the brain.
‘This research did not involve people with dementia, but the mild memory problems explored here can be a precursor to dementia, and understanding why some people go on to develop the condition while others do not could help prevention efforts.
‘There are many reasons to keep healthy in middle age, and other research has previously suggested that our health in midlife can affect our risk of cognitive decline and dementia in later life.
‘Continued investment in research is important to better understand the different factors that can affect our risk of dementia and the ways it might be prevented.
‘In the meantime, other evidence shows we can lower our risk by eating a healthy, balanced diet, not smoking, taking regular exercise, keeping weight in check and controlling blood pressure.’