How does diabetes destroy the brain

How type 2 diabetes damages the brain

Boston - Long-standing type 2 diabetes disrupts the regulation of cerebral blood flow, which was shown in a prospective observational study in Neurology (2015, doi: 10.1212 / WNL.0000000000001820y) already had an impact on the cognitive performance of patients after two years.

The healthy brain can adjust the blood flow as needed. Brain regions that are particularly stressed receive more oxygen and glucose, the main energy carrier for nerve cells, for the duration of the increased brain activity. In patients with type 2 diabetes, this regulation of cerebral blood flow is restricted, claims Vera Novak of Harvard Medical School in Boston, which has carried out studies with magnetic resonance imaging (MRI) in 40 seniors. She used the so-called arterial spin marking, with which the blood flow in the brain can be measured in the MRI.

The 40 participants were examined twice every two years. Cognitive tests were also carried out. Nineteen participants had type 2 diabetes. They had been diagnosed with the disease an average of 13 years ago. Even during the first examination, the brain's ability to adapt blood flow to needs was limited. In the second examination, the regulation had deteriorated further. At the same time, there was a deterioration in the tests for memory formation and thinking skills. The patients' ability to cope with everyday life, such as bathing or cooking independently, had also declined.

In a test on the ability to learn and memory, the results of the diabetics worsened from 46 points to 41 points within just two years, while the healthy comparators were able to maintain their results with 55 points. The regulation of blood flow in the brain deteriorated by 65 percent in diabetics over the same period.

In addition to the increased blood sugar, according to Novak, inflammation parameters also had an influence on the cerebral hemorrhage. An increased C-reactive protein on the first examination indicated a greater decrease in blood flow regulation. In previous studies, Novak had been able to show that long-term diabetes leads to atrophy of the brain. According to Novak, the frontal and temporal regions, which are responsible for decision-making, language, word memory and complex tasks, are most at risk. The current study attributes these weaknesses to disorders of the cerebral blood flow. © rme / aerzteblatt.de