One study found that patients taking metformin had a 20 percent lower risk of developing dementia.
A medication for diabetes called metformin may help more than just control blood sugar levels: new research indicates that it may also reduce the risk of developing dementia.
Compared to other people taking another medication for diabetes called sulfonylureas, people who took metformin had a 20 percent reduction in the risk of developing dementia in the five-year study period
“Metformin may have a protective effect on the brain,” said study author Dr. Rachel Whitmer, an epidemiologist in the research division of Kaiser Permanente in Oakland, Calif.
However, Whitmer cautioned that: “The study was observational, retrospective based on a defined population, we found an association but the cause and effect were not determined.
Whitmer plans to present his research findings Monday at the International Conference of the Alzheimer’s Association in Boston. Research presented at medical meetings is considered preliminary until it is published in peer-reviewed journals.
According to the background of the study, people with type 2 diabetes have twice the risk of developing dementia, compared to someone who does not. Although diabetes is a major risk factor for developing dementia, the researchers found that there are very few studies investigating the effects of diabetes medications on the risk of dementia.
To determine if a treatment can offer some protection against dementia, Dr. Whitmer and her colleagues reviewed the data of nearly 15,000 people with type 2 diabetes who had just started a single drug therapy for this disease.
All the people who were part of this study were 55 or older and all had been diagnosed with type 2 diabetes. Whitmer said none of these people had a recent diagnosis; some of these people had been diagnosed with type 2 diabetes for 10 years, but none of them had taken medication for the disease when the study began.
“These people started treatment with one of the four medications of the therapies: metformin, sulfonylureas, thiazolidinediones (TZDs) or insulin,” said Whitmer.
These medications lower blood sugar levels, but act a bit in different ways.
Metformin makes muscle tissue more receptive to insulin, a hormone needed for sugar (glucose) to reach body cells and tissues for energy. It also decreases the production of glucose in the liver. Sulfonylureas, stimulates the production of insulin. TZD, makes muscles and fatty tissue more receptive to insulin and decreases the amount of glucose that is generated in the liver. Insulin injections are used to help fill the need for more insulin since people with type 2 diabetes can not use the insulin produced by the body efficiently.
During the study, almost 10 percent of the patients were diagnosed with dementia. (The study could not differentiate between Alzheimer’s disease and other forms of dementia, Whitmer said)
According to the study, comparing people who took sulfonylureas with those who took metformin, those who took metformin showed a 20 percent decrease in the risk of developing dementia. There were no differences in the risk of dementia for those who had the drug TZD or insulin compared to people who were under the drug sulfonylureas.
The researchers controlled the data by a number of factors, including age, duration of diabetes, blood sugar control, race and education, Whitmer said.
So, what is in metformin that could help protect the brain? Whitmer said that a theory originated from animal research is that metformin can play a role in the development of new cells in the brain (neurogenesis). It has also been associated with inflammation reduction, she added.
One expert was very interested in the discoveries.
“Insulin promotes the survival of certain nerve cells.” A drug such as metformin, which is an insulin sensitizer in the body, can also be a sensitizer in the brain, “said Dr. Richard Lipton, director of the division. of cognitive aging and dementia of the Montefiore Medical Center in New York City. “We know that people with Alzheimer’s disease lose brain volume, which may be due to poor nerve cell replacement.” The notion that metformin could promote neurogenesis and cell replacement in the brain is a very attractive hypothesis.”
“The idea of how we treat diabetes and the effects it can have on the cause of dementia is exciting,” Lipton said.
Whitmer hopes to do more research to determine whether long-term use of metformin might have a greater effect, if increasing the dose could make a difference and if there could be a difference in risk reduction based on the type of dementia.
For now, she said, it is important to remember this: “The brain is not an isolated thing.When one thinks about the health of the brain one must think about the health of the whole body, and throughout life.” Dementia appears late in life, but these changes begin a decade or long before they manifest, what is healthy for the heart is also healthy for the brain.
Nancy Miller (MD) has over 20 years experience as a educator and health practitioner. She has a B.S. from Lake Head University In Thunder Bay, and a Ph.D. in biology from the University of Guelph . Dr. Miller has worked as a special medical consultant for a major insurance provider before becoming a freelance health author and public speaker. There are several ways to contact Dr. Miller here.