Study: Type 2 Diabetes Reduces Brain Function Within Just Two Years

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A new study published in the journal Neurology shows that Type 2 diabetes triggers a significant reduction in cognitive ability within just a two-year period. The main culprits appear to be increased tissue inflammation and decreased blood flow to the brain.
Researchers conducted several tests on 65 participants (average age 66) at the beginning of a two-year study, roughly half of whom had already been diagnosed with Type 2 diabetes. All of the participants took tests to assess cognitive function and memory performance, and underwent MRI scans and blood tests to measure blood flow and pressure, rate of tissue inflammation, and brain volume.
The tests were repeated after two years, with the following results:
Thinking and memory test scores for participants with Type 2 diabetes dropped 12% over the two-year period. Test scores for participants without diabetes remained steady.
Participants with Type 2 diabetes experienced a 65% decrease in blow flow regulation.
The diabetic participants also experienced a 50% decline in “vasoreactivity” – the ability of blood vessels to contract in response to stimuli, a key indicator of blood vessel health.
“People with type 2 diabetes have impaired blood flow regulation,” according to study co-author Vera Novak, MD, PhD, of Beth Israel Deaconess Medical Center in Boston. “Our results suggest that diabetes and high blood sugar impose a chronic negative effect on cognitive and decision-making skills.”
Negative effects of diabetes on blood flow and blood vessel function are well-evidenced in prior research, but this study added the dimension of linking these effects to changes in brain function over a brief window of time.
“These correlations provided the link between altered cerebral vasoregulation and cognitive deterioration in participants with type 2 diabetes that can be tracked prospectively even over a relatively short time period of 2 years,” according to the research team.
Although this was a small study that should be validated with larger groups of participants, the results further substantiate a link between diabetes and cognitive impairment. Previous studies have found a similar link, including a potential link between diabetes and Alzheimer’s disease.

“Early detection and monitoring of blood flow regulation may be an important predictor of accelerated changes in cognitive and decision-making skills,” Novak said in a statement.

The study was published in the journal Neurology.