Study shows long-term effects of type 2 diabetes on the brain, thinking
News Jul 10, 2015
In just two years, people with type 2 diabetes experienced negative changes in their ability to regulate blood flow in the brain, which was associated with lower scores on tests of cognition skills and their ability to perform their daily activities, according to a new study published online in Neurology, the medical journal of the American Academy of Neurology.
“Normal blood flow regulation allows the brain to redistribute blood to areas of the brain that have increased activity while performing certain tasks,” said study author Vera Novak, MD, PhD, of Harvard Medical School in Boston. “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.”
The study involved 40 people with an average age of 66. Of those, 19 had type 2 diabetes and 21 did not have diabetes. Those with diabetes had been treated for the disease for an average of 13 years. The participants were tested at the beginning of the study and again two years later. Tests included cognition and memory tests, MRI scans of the brain to look at brain volume and blood flow, and blood tests to measure control of blood sugar and inflammation.
After two years, the people with diabetes had decreases in their ability to regulate blood flow in the brain. They also had lower scores on several tests of memory and thinking skills. People with lower ability to regulate blood flow at the beginning of the study had greater declines in a measure of how well they could complete daily activities such as bathing and cooking.
Higher levels of inflammation were also associated with greater decreases in blood flow regulation, even if people had good control of their diabetes and blood pressure, Novak said.
On a test of learning and memory, the scores of the people with diabetes decreased by 12 percent, from 46 points to 41 points over the two years of the study, while the scores of those without diabetes stayed the same, at 55 points. Blood flow regulation in the brain was decreased by 65 percent in people with diabetes.
“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.
Note: Material may have been edited for length and content. For further information, please contact the cited source.
Novak V et al. Inflammation-associated declines in cerebral vasoreactivity and cognition in type 2 diabetes. Neurology, Published Online July 8 2015. doi: 10.1212/WNL.0000000000001820
Adult depression has long been associated with shrinkage of the hippocampus, a brain region that plays an important role in memory and response to stress. Now, new research has linked participation in team sports to larger hippocampal volumes in children and less depression in boys ages 9 to 11.
Researchers have discovered a brain process common to sleep and ageing in research that could pave the way for new treatments for insomnia. The scientists report how oxidative stress leads to sleep. Oxidative stress is also believed to be a reason why we age and a cause of degenerative diseases.READ MORE
Patients in a new Northwestern Medicine study were able to comprehend words that were written but not said aloud. They could write the names of things they saw but not verbalize them. This provides an insight into the brain degeneration that defines the rare dementia termed primary progressive aphasia.