Diabetes medication may help reduce severity of Alzheimer's disease

According to a new research, people with Alzheimer's disease who were treated with diabetes drugs showed considerably fewer markers of the disease including abnormal microvasculature and deregulated gene expressions in their brains, compared to patients who were treated using other kinds of drugs.

The study was performed by the researchers of Mount Sinai School of Medicine, results of which were published in the journal of 'PLOS One'.

This is the first study to examine what happens in the pathways of brain tissues and endothelial cells, the cells lining blood vessels in the brains of Alzheimer's patients treated with diabetes medication. The results of the study will help future Alzheimer's disease studies and potential new therapies targeting specific cells since they suggest that targeting the brain's capillary system could have beneficial effects in Alzheimer's patients.

Many elderly people with diabetes have brain changes that are hallmarks of Alzheimer's. Despite this linkage, two previous Mount Sinai studies on brain tissue found that the brains of people with both Alzheimer's disease and diabetes had fewer Alzheimer's lesions than the brains from people with Alzheimer's disease without diabetes.

The results suggested that anti-diabetes medications had a protective effect on the brains of Alzheimer's disease patients.

To determine what happens at the molecular level, the research team developed a method to separate brain capillaries from the brain tissue of 34 people with Alzheimer's and type 2 diabetes who had been treated with anti-diabetes drugs and compare them to tissue from 30 brains of people with Alzheimer's without diabetes and 19 brains of people without Alzheimer's or diabetes.

Researchers then examined the vessels and brain tissues separately to measure Alzheimer's disease-associated changes in molecular RNA markers for brain capillary cells and insulin signaling.

The levels of about half of these markers were reduced in the vessels and brain tissue in the group with Alzheimer's and diabetes. The great majority of the RNA changes seen in Alzheimer's disease were absent in those Alzheimer's patients who had been treated with anti-diabetes drugs.

"The results of this study are important because they give us new insights for the treatment of Alzheimer's disease," said the study's senior author, Vahram Haroutunian.

"Most modern Alzheimer's treatments target amyloid plaques and haven't succeeded in effectively treating the disease. Insulin and diabetes medications such as metformin are FDA approved and safely administered to millions of people and appear to have a beneficial effect on people with Alzheimer's. This opens opportunities to conduct research trials on people using similar drugs or on drugs that have similar effects on the brains' biological pathways and cell types identified in this study," said Dr. Haroutunian.