Scientists find diabetes treatment drugs could impact on Alzheimer's disease
Drugs used to treat diabetes may also be effective against Alzheimer's disease, new research suggests.
Scientists have found that the two conditions are strongly linked, raising the possibility of shared drug responses.
Medicines currently used to control glucose levels in diabetes may also alleviate the symptoms and progression of Alzheimer's, the team claims.
The study showed for the first time that dementia-related effects in the brain can lead to changes in the body's handling of glucose, and ultimately to diabetes.
Researchers at the University of Aberdeen investigated why the two conditions are so often found together in elderly patients.
Studying Alzheimer's disease in mice, they found that increased activity of a gene involved in the production of toxic brain proteins was also linked to diabetic complications.
Lead scientist Professor Bettina Platt said: "Many people are unaware of the relationship between diabetes and Alzheimer's disease, but the fact is that around 80% of people with Alzheimer's disease also have some form of diabetes or disturbed glucose metabolism.
"This is hugely relevant as Alzheimer's is in the vast majority of cases not inherited, and lifestyle factors and comorbidities (co-existing conditions) must therefore be to blame.
"Our research teams are particularly interested in the impact of lifestyle related factors in dementia and by collaborating with experts in diabetes and metabolism, we have been able to investigate the nature of the link in great detail.
"Until now, we always assumed that obese people get Type 2 diabetes and then are more likely to get dementia. We now show that actually it also works the other way around."
The findings, published in the journal Diabetologia, indicate a "new therapeutic angle" to treating Alzheimer's, she said.
Prof Platt added: "We now think that some of the compounds that are used for obesity and diabetic deregulation might potentially be beneficial for Alzheimer's patients as well.
"The good news is that there are a number of new drugs available right now which we are testing to see if they would reverse both Alzheimer's and diabetes symptoms.
"We will also be able to study whether new treatments developed for Alzheimer's can improve both, the diabetic and cognitive symptoms."
Dr James Pickett, head of research at the charity Alzheimer's Society, said there was already evidence of an association between Type 2 diabetes and Alzheimer's but the underlying mechanisms were unclear.
Despite the results in mice, more research was needed to see if the findings also applied to people.
Dr Pickett said: "This research does not mean people with diabetes should be unduly worried about their risk of getting dementia.
"Anyone who is worried should visit their GP for advice on how to correctly manage their condition. Other ways to reduce your risk of dementia are to take regular exercise, avoid smoking and eat a healthy, balanced diet."
Dr Rosa Sancho, from the charity Alzheimer's Research UK, said: "Clinical trials are currently under way to determine whether medications for diabetes could benefit people with Alzheimer's and a better understanding of this link is crucial as researchers seek to find new ways of tackling both diseases.
"Diabetes is one risk factor for Alzheimer's but the disease is caused by a complex mix of age, genetics and lifestyle factors."