Diabetes Doubles Risk of Dementia
New research suggests that the tangles of proteins found in the brains of Alzheimer’s disease patients are also common among people with type 2 diabetes. And that may help explain why diabetes patients are significantly more likely to develop the mind-robbing disease.
"Evidence shows that people with type 2 diabetes have double the risk of developing dementia," said study author Velandai Srikanth, MD, PhD, from Monash University in Melbourne, Australia. "This interesting development further defines how the diseases may be connected.”
The study examined the relationships among type 2 diabetes, brain cell loss, loss of connections among brain cells, buildup of beta amyloid (a sticky protein that forms plaques in the brain), and tau protein, which accumulates as tangles within the cerebrospinal fluid of Alzheimer’s disease sufferers.
Diabetes patients had consistent evidence of more tau protein in their spinal fluid than non-diabetic patients. Investigators speculate that this may reflect the formation of tangles in the brain itself. These tangles are a hallmark of Alzheimer’s-type dementia.
Diabetes patients also tended to have thinner cortexes than non-diabetic patients. This loss of brain tissue may also reflect the buildup of these tangles. "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," said Srikanth.
Evidence suggests that most cases of type 2 diabetes, which is at epidemic levels now in the developed world, may be preventable, or even reversible, with appropriate lifestyle changes, such as maintaining a healthy body weight, adopting a Mediterranean-style diet, and getting regular exercise.
C. Moran, R. Beare, T. G. Phan, D. G. Bruce, M. L. Callisaya, V. Srikanth. Type 2 diabetes mellitus and biomarkers of neurodegeneration. Neurology, 2015; DOI: 10.1212/WNL.0000000000001982
Troughton J, Chatterjee S, et al. Development of a lifestyle intervention using the MRC framework for diabetes prevention in people with impaired glucose regulation. J Public Health (Oxf). 2015 Aug 25. pii: fdv110. [Epub ahead of print]