Research Team
Shannon Halloway, Principal Investigator, Rush University College of Nursing
Michael Schoeny, Co-Investigator, Rush University College of Nursing
Lisa Barnes, Co-Investigator, Rush University Medical College
Laura Baker, Co- Investigator, Wake Forest School of Medicine
Project Period
1/1/2020 - 12/31/2020
Funding Source
Institute of Translational Medicine (CTSA) Pilot Grant
Abstract
Problem: Alzheimer’s dementia (AD) is a progressive, degenerative brain disorder affecting 5.8 million adults 65 years or older in the United States, rapidly increasing to over 10 million by 2025 due to the growing older adult population. AD is related to decreased quality of life, strained family relations, and growing healthcare costs. Although some degree of cognitive decline, including worsened memory, is regarded as normal with aging, accelerated cognitive decline can manifest prior to AD diagnosis and treatment. So far, there are no proven pharmacological treatments for cognitive decline. However, evidence is accumulating that certain lifestyle behaviors may mitigate cognitive decline in healthy older adults.
Our long-term goal is to prevent the onset of cognitive decline through effective lifestyle multimodal interventions. Rush University Medical Center is 1 of 3 sites of the U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (U.S. POINTER), a promising 2-year lifestyle multimodal prevention intervention trial targeting cognitive decline. U.S. POINTER will study 2,000 community-dwelling older adults across the nation who are at-risk for AD due to a cardiometabolic risk factor and first-degree family history of memory impairment. U.S. POINTER promotes moderate-vigorous physical activity, which is known to improve brain health, in a package comprised of multiple lifestyle intervention components, and has several unique strengths. First, U.S. POINTER promotes physical activity by emphasizing a lifestyle approach to incorporate a variety of activities throughout daily life. Second, the multidisciplinary U.S. POINTER team represents all major U.S. regions, engaging an impressive array of community stakeholders. Third, multiple valid and reliable measures are utilized to capture a variety of movement behaviors (e.g., physical activity, sedentary behavior): an accelerometer reliably captures intensity, duration, frequency, and bouts, while self-report questionnaires capture type and domain of activity.
Prior trials testing multimodal interventions targeting cognitive decline found significant effects of moderate-vigorous physical activity. However, some effects were small and short-acting, possibly due to key limitations. For example, these trials largely used highly structured exercise instead of a lifestyle approach, which is preferred by older adults, and encourages long-term adherence. Further, most trials relied on self-report questionnaires alone, failing to accurately capture all characteristics of movement behaviors. Differences in such characteristics, such as intensity, duration, and type have been related to various health benefits, but have yet to be tested in cognition studies.
Another major limitation of the prior trials is the lack of attention to sedentary behavior (time spent sitting or lying). We and others have shown that participants in physical activity interventions who increase moderate-vigorous physical activity may also have unintended increases in sedentary behavior. This is a significant problem due to the known deleterious effects of sedentary behavior on cognitive function, AD brain pathologies, and general health. We will address this limitation by examining the potential impact of sedentary behavior that may counter the cognitive benefits of physical activity in U.S. POINTER participants.
Solution: We propose leveraging the breadth of data that will be collected in the multi-site U.S. POINTER trial. U.S. POINTER’s comprehensive dataset includes extensive neurocognitive testing and multiple measures of movement behaviors, all of which will be collected annually in a large representative sample. We ultimately plan to investigate the potential impact of sedentary behavior on cognitive function as participants increase moderate-vigorous physical activity. The first step in this program of research is to examine the movement behaviors of U.S. POINTER participants at baseline.
The purpose of the proposed pilot study is to conduct secondary analyses of the U.S. POINTER trial data to explore the degree to which sedentary behavior offsets the benefits of moderate-vigorous physical activity on cognitive function. We will also develop profiles based on the movement behavior data as measured by both accelerometer and questionnaires, and evaluate differences in cognitive function across these profiles.