"Evidence shows that people with type 2 diabetes have double the risk of developing dementia," study author Velandai Srikanth, MD, PhD, said in a press release. "This interesting development further defines how the diseases may be connected."
Research studied 816 people who had an average age of 74. Close to 400 study participants had mild cognitive impairment, nearly 200 had been diagnosed with Alzheimer's, and roughly 230 had no memory or thinking problems. 124 participants had diabetes. "The study looked at the relationship between type 2 diabetes, the loss of brain cells and their connections, the levels of beta amyloid (a sticky buildup of plaques) and tau or tangles of protein in the spinal fluid of the participants," the press release stated.
People with diabetes had greater levels of tau protein in their spinal and brain fluid, which may reflect a greater build-up of tangles in the brain -- tangles that could contribute to the development of dementia. It also found that diabetes was associated with a reduced thickness in the cortex, which is the layer of the brain with the most nerve cells. The build-up of tangles can contribute to the loss of this brain tissue.
"Due to the fact that nerve cells in the brain do not replace themselves, it is extremely important to find ways to reduce the death of current brain cells. Studies such as ours seek to understand how diseases like diabetes may directly or indirectly affect brain cell death," Srikanth said.