The study included 816 participants, of which 124 had diabetes, 397 had mild cognitive impairment, 191 had Alzheimer’s disease and 228 had no memory and thinking problems. The average age of the study participants was 74.
On average, participants who had diabetes exhibited16 picograms per milliliter greater levels of the tau protein in the spinal and brain fluid, regardless of whether or not they suffered from dementia, which may reflect a greater buildup of tangles in the brain.
According to study author Velandai Srikanth, M.D., Ph.D., “Evidence shows that people with type 2 diabetes have double the risk of developing dementia. This interesting development further defines how the diseases may be connected.”
The study related that the accumulation of tangles may also contribute to the loss of brain tissue. Additionally, diabetes was associated with an average of 0.03 millimeter less cortical tissue in brains of participants who had diabetes than those who did not.
Srikanth explained that because of the fact that nerve cells in the brain fail to 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.”
The study did not determine a cause-and-effect relationship between diabetes and brain tangles.
Researchers from the Mayo Clinic have made the case for a link between type 2 diabetes and Alzheimer’s disease, labeling Alzheimer’s disease “type 3 diabetes.” Their studies show that people with diabetes, especially type 2 diabetes, are at higher risk for eventually developing Alzheimer's disease or other dementias.