leisel ann meusel

Dr. Liesel Ann Meusel ~ 2014

Exploring the link between diabetes and Alzheimers.

Diabetes is the result of our body's inability to properly absorb sugar and now some researchers think the same thing can happen in the brain, and that it may contribute to dementia.

That has Alzheimer’s researchers, such as neuroscientist Liesel-Ann Meusel, probing deeper to see how much stock to put in this theory. And if there is something to it, she wants to find a way to intervene early, perhaps even before memory problems surface

As a post-doctoral researcher at The Rotman Research Institute, Meusel will spend the next two years scanning volunteers’ brains and assessing them for signs of impaired function. She is particularly interested in results from those with type 2 diabetes.

That’s because various studies over the past decade have suggested significant links between Alzheimer’s disease and this form of diabetes.

In type 2 diabetes, our bodies’ cells don’t respond to the insulin we produce to help them take up sugar. The same thing happens in the brain cells of people with Alzheimer’s disease.  In addition, as people with type 2 diabetes age, they often develop the same brain plaques and tangles associated with Alzheimer’s disease. And finally, people with type 2 diabetes have a higher risk of developing Alzheimer’s.

“While type 2 diabetes doesn’t cause Alzheimer’s, we know there are similar mechanisms at work and we are trying to understand those links,” says Meusel, whose study is funded by the Alzheimer Society of Ontario and the Firefly Foundation.

Comparing brains at rest she will use functional MRI scans to compare the brain activity of 100 participants aged 65 to 85. Participants will be divided into four groups – those with no health issues, those with high blood pressure, those with type 2 diabetes and high blood pressure, and those with pre-type 2 diabetes and high blood pressure.

Many people with diabetes and pre-diabetes also have high blood pressure, so dividing the groups this way allows her to rule out the effect of high blood pressure.

Meusel will compare each group’s brain activity while at rest. If those with diabetes and pre-diabetes have less active brains than those without these illnesses, it will suggest diabetes and pre-diabetes do in fact impair brain function.

It will also underline the importance of catching and treating diabetes early.

“If we better understand the link for individuals who have diabetes, we can better manage it and figure out ways to delay or offset dementia,” says Meusel.

spark award: $100,000

Alzheimer disease and type 2 diabetes mellitus share a common pathology (namely, insulin resis-tance), and Alzheimer’s disease is thought to be a type of diabetes that affects the brain, specifically. While type 2 diabetes does not cause Alzheimer’s directly, it contributes to the progression of neurodegeneration; effects that are mediated by increasing brain insulin resistance. There is an abundance of research on the cognitive, structural, and functional brain changes in Alzheimer disease, but the early consequences of insulin resistance on functional brain networks are understudied. To address this, my project will use functional magnetic resonance imaging to study brain networks in individuals with type 2 diabetes, a condition that results in mild brain insulin resistance. This research will provide information about the early effects of insulin dysregulation on brain function and progression of Alzheimer pathology. This work may uncover potential targets for early intervention that could delay dementia onset.