Grant: Doctoral Award - Frederick Banting and Charles Best Canada Graduate Scholarships

As Canada's population ages, dementia will become a significant health care burden. In 2008 approximately half a million Canadians suffered from dementia. By 2038, over a million Canadians will have dementia and their care will cost over $150 billion. Alzheimer's disease (AD) and vascular cognitive impairment (VCI) are the two most common forms of dementia. AD is characterized by the accumulation of amyloid-beta (A-beta) plaques and neurofibrillary tangles. VCI is caused by hemorrhagic brain lesions or diffuse ischemia in the brain and is characterized by subcortical lesions such as white matter lesions (WMLs). Traditionally, these pathogenic mechanisms were considered to be distinct and unrelated. However, we now know that AD and VCI can and do co-exist (i.e., mixed dementia). Currently, little is known about how WMLs and A-beta plaques interact to affect cognitive function. Furthermore, it is unknown whether the presence of both WMLs and A-beta plaques attenuates the effect of interventions such as exercise. Yet, the answers to these questions are important towards ensuring optimal care for those exhibiting mixed dementia-related changes. Our objective is to 1) To compare cognitive function between those with WMLs and those with A-beta+WMLs and 2) To determine whether A-beta+WMLs attenuates the effect of targeted aerobic exercise training on cognitive function. Gaining a deeper understanding of the interplay between WMLs, A-beta, and targeted exercise training will facilitate the development of effective prevention strategies for cognitive decline. Strategies to slow down the rate of cognitive decline could preserve independent functioning and quality of life in this population. This, in turn, could lead to reduced health care utilization costs and avoidance of early institutional care.