People with type 2 diabetes more prone to Alzheimers brain tangles

Type 2 diabetes makes you more likely to develop ‘brain tangles’ associated with Alzheimers disease, according to new research.
The study, conducted by researchers at Monash University in Melbourne, Australia, found that type 2 diabetes triggers brain abnormalities. These abnormalities, combined with degenerative changes in the brain, can cause dementia. The findings could explain why people with type 2 diabetes are more likely to develop Alzheimer’s disease.
The findings are promising, but only show a correlation between type 2 diabetes and higher levels of brain tangles. More research is needed to confirm a causal link.
Other factors may be the cause. For example, many people with type 2 diabetes – but by no means all – are also obese. It could be obesity that causes the build-up of brain tangles, thereby increasing the risk of dementia.
The researchers analysed the data of 124 older adults with type 2 diabetes, and compared them to 700 without diabetes. The participants varied in terms of their cognitive function: some had Alzheimer’s, some had mild memory and thinking problems, and others had no cognitive problems at all.
The participants took part in MRI scans, and half of them provided samples of cerebrospinal fluid, which was used to measure the levels of two proteins associated with Alzheimer’s: beta-amyloid and tau. In brains affected by Alzheimer’s disease, these proteins make up the many plaques and tangles.
The results suggest that people with diabetes experience thinning in the brain cortex, and have higher tau protein in their spinal fluid. The more tau in the spinal fluid, the more tangles in the brain.
The study was described as important by Kalipada Paha, a Professor of Neurological Sciences at Rush University Medical Centre in Chicago, as “important.”
“It clearly shows that type 2 diabetes is associated with an increase in [tau] and a decrease in cortical thickness,” said Pahan.
“Type 2 diabetes cannot be the only mechanism for tau pathology. Obesity, abnormal fat metabolism and many other health issues may lead to tau pathology via different pathways.
“It is possible that glycation of an important brain protein is involved in tau build-up.”
The researchers hope to develop the findings to definitively explain the link between type 2 diabetes and Alzheimer’s disease, the causes of which remain somewhat mysterious. It could be to do with obesity, or it could be to do with high blood glucose levels. The researchers note that there exists “an interesting body of evidence” that links obesity to heightened tau levels.
Historically, no such link has been discovered between type 1 diabetes and Alzheimer’s disease, which suggests there is something more to the connection than only chronic high blood glucose levels.
The findings were published in Neurology.