Researchers have discovered that for people with Type 2 diabetes, cognitive decline is likely the result of brain atrophy, similar to what is seen in the early stages of Alzheimer’s disease.
Investigators from Australia’s Monash University compared brain scans and cognitive function among people with and without Type 2 diabetes mellitus.
They found that brain atrophy, rather than cerebrovascular lesions, was likely the primary reason for cognitive impairment associated with this form of diabetes.
Type 2 diabetes is reaching epidemic status in several states and countries, often a result of wide-spread obesity. Globally, the World Health Organization reports that more that more than 347 million people worldwide live with diabetes and around 90 per cent of these cases are Type 2.
Researchers say the findings have important implications for countries experiencing population shifts associated with large numbers of baby boomers entering their senior years.
“Type 2 diabetes and dementia are both highly common disorders affecting the aging population and this research shows that there may be a mechanistic link between them. Indeed, generalized brain atrophy may be the key driver of cognitive decline in Type 2 diabetes and such atrophy is also commonly seen in people with dementia,” said Dr. Velandai Srikanth.
Researchers are concerned the future populations will be burdened by elderly people with dementia and cognitive decline.
The research built on previous studies that had shown there may be a greater risk of future dementia in people with Type 2 diabetes. However, it was unclear whether this form of diabetes was an actual causal factor for the development of cognitive impairment.
The researchers compared cognitive function and magnetic resonance imaging (MRI) scans of the brain in more than 700 people with and without Type 2 diabetes.
Those with diabetes performed less well in certain cognitive tests and had greater shrinkage in specific regions of the brain, which appeared to drive the differences in cognitive function.
Although the researchers found that participants with diabetes also had more strokes on MRI, this did not explain the cognitive differences between groups.
The findings, published in the journal Diabetes Care, will lead further research in trying to identify why people with Type 2 diabetes develop brain atrophy, and how such atrophy may be prevented or slowed.