Midlife onset of diabetes linked to brain damage

People who develop diabetes and high blood pressure in middle age may be more at risk of suffering brain cell loss and subsequent problems with cognitive function, a new study has found.
For the study, a team of US-based researchers assessed the thinking and memory skills of 1,437 individuals with an average age of 80 who either had mild cognitive impairment or no memory and/or thinking problems.
Each participant also underwent brain scans to test for markers of brain damage that can be a precursor to dementia, and their medical records reviewed to determine their history of diabetes and high blood pressure (hypertension), and whether they had been diagnosed with either condition in middle age (ages 40-64) or later.
The research team found that of those who went on to develop diabetes, 72 people were diagnosed with the disease in middle age and 142 in old age. For those with hypertensio, 449 people developed it in middle age and 448 in old age.
The results of the brain scans showed that compared to non-diabetic participants, people who developed diabetes in middle age had a 2.9% smaller total brain volume on average, rising to 4% in the hippocampus area of the brain which is primarily associated with memory. They were also twice as likely to have thinking and memory problems.
For people with hypertensio, those who developed it in middle age had double the risk of brain damage than participants without high blood pressure.
The team also found that while developing diabetes in old age was linked to greater risk of having areas of brain damage developing high blood pressure in old age did not appear to have any adverse effects on the brain.
Study author Rosebud Roberts, a member of the American Academy of Neurology, said: “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.
“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,” he added.
The study findings are published in the online issue of Neurology, the official journal of the American Academy of Neurology.