2023 Alzheimer's Association Research Fellowship to Promote Diversity (AARF-D)
Affective Mechanisms of the Decline in Physical Activity in Preclinical AD
How may mood and Alzheimer’s-related brain changes interact to influence physical activity levels?
Marta Stojanovic, Ph.D.
Washington University in St.Louis
St. Louis, MO - United States
Background
Researchers believe that Alzheimer’s and other dementia, like many chronic diseases, develop as a result of multiple factors rather than a single cause. New research suggests some risk factors for Alzheimer’s are modifiable. Individuals may be able to delay or slow disease progression by modifying factors such as physical activity. Studies have linked sustained exercise and physical activity with improved cognition, increases in brain volume, and reduced Alzheimer’s-related brain changes. Despite the potential benefits of exercising for older adults, individuals at risk of developing Alzheimer’s show lower levels of physical activity and more sedentary behavior.
Dr. Marta Stojanovic and colleagues believe that affective factors (factors relating to moods or feelings) may play a role in physical activity levels in individuals at risk for Alzheimer’s.
Research Plan
The researchers will study the relationships between Alzheimer’s-related brain changes, affective factors, and physical activity. They will recruit cognitively unimpaired middle-aged and older adults through the long-term Adult Children Study at Washington University Knight Alzheimer Disease Research Center. Dr. Stojanovic and colleagues will first investigate whether Alzheimer’s-related brain changes and mood contribute to physical activity levels. The researchers will use brain scans (positron emission tomography, PET) to measure levels of the protein tau, which forms clumps called tangles in a hallmark brain change associated with Alzheimer’s. They will estimate physical activity using actigraphy (a non-invasive method of recording human sleep-wake cycles) and collect measures of mood. Next, Dr. Stojanovic and team will collect measures of mood before and after moderate exercise to see whether Alzheimer’s-related brain changes and affective response to exercise contribute to physical activity levels. Finally, the team will use another type of brain scan (functional magnetic resonance imaging, fMRI) to study the role that brain networks involved in mood influence physical activity.
Impact
The results may shed light on why older adults at risk for Alzheimer’s show decreased physical activity levels and support the use of exercise as a potential avenue for reducing risk of cognitive decline and Alzheimer’s in older individuals.