Grant: CIHR Fellowship

Vascular cognitive impairment (VCI) refers to the loss of cognitive and brain function due to blocked or narrowed arteries in the brain. Very often, these blockages are in the small arteries of the brain and are only diagnosed with brain scans. Another feature of VCI is myelin loss; myelin is critical for the proper transmission of signals within the brain. Thus, myelin loss is associated with impaired cognitive function and mobility. Importantly, VCI is the second most common cause of dementia in the world. Fortunately, VCI may be the most treatable form of cognitive impairment as many of its key risk factors, such as high blood pressure, diabetes and high cholesterol, can be reduced with lifestyle changes. While we know that exercise is effective in reducing these risk factors, little research has been done specifically in persons with VCI to determine whether exercise can slow down the disease progression. Specifically, despite evidence that shows strength training (i.e., lifting weights) can reduce the damage due to blocked small arteries, current VCI research focus solely on aerobic training (e.g., running, walking). Moreover, no study has examined whether exercise of any type can reduce myelin loss over time in persons with VCI. Based on our prior work, we propose that strength training is an effective treatment strategy for slowing down disease progression in persons with VCI. Using a special brain scan, we will evaluate the effects of twice-weekly strength training on myelin over a 12-month period in persons with VCI compared to an active control group. We will also examine how strength training may minimize myelin loss in VCI by examining levels of neurotrophic growth factors in the blood. Our proposal is very practical as exercise may be an effective, inexpensive, and accessible intervention strategy with minimal side effects. Our proposal is also timely as the prevalence and burden of VCI will only increase due to the world's aging population.