In as little as two years, Type 2 diabetes damages the way blood flows to the brain. The negative changes are associated with lower scores on tests measuring cognitive skills and the ability to perform activities of daily living, a new study from Harvard University found.
The small study, published July 8 in Neurology, found people with Type 2 diabetes experienced negative changes in their ability to regulate blood flow to the brain.
“Normal blood flow regulation allows the brain to redistribute blood to areas of the brain that have increased activity while performing certain tasks,” study author Vera Novak, MD, PhD, of Harvard Medical School in Boston, said in a press release from the American Academy of Neurology, which publishes the journal. “People with Type 2 diabetes have impaired blood flow regulation. Our results suggest that diabetes and high blood sugar impose a chronic negative effect on cognitive and decision-making skills.”
Memory and diabetes
For the study, researchers followed 40 adults with an average age of 66; 19 had Type 2 diabetes while the remaining 21 did not. On average, those with diabetes had been receiving treatment for the disease for 13 years.
At the beginning of the study, participants underwent cognition and memory tests, MRI scans of the brain to measure brain volume and blood flow, and blood tests to measure control of blood sugar and inflammation. They were tested again two years later.
At the two-year mark, people with diabetes showed declines in their ability to regulate blood flow to the brain. Blood flow regulation in the brain decreased 65 percent among people with diabetes, researchers found.
In addition, their scores on the cognition and memory skills tests declined. On a test measuring memory and learning, scores for people with diabetes decreased by 12 percent, while the scores of those without diabetes remained the same.
People whose ability to control blood flow to the brain were the lowest when the study began showed greater declines in how well they were able to perform everyday tasks such as bathing and cooking, Novak said.
Blood sugar control has little impact
Higher levels of inflammation were also associated with greater decreases in blood flow regulation, even among subjects who had good blood sugar control.
“Early detection and monitoring of blood flow regulation may be an important predictor of accelerated changes in cognitive and decision-making skills,” Novak said. She said additional studies involving more people and extending for a longer time period are needed to better understand the relationship and timing with blood flow regulation and changes in thinking and memory skills.
The study was supported by the National Institute on Aging, American Diabetes Association, Harvard Clinical and Translational Science Center and National Center for Research Resources.
