Evaluating Effects in the Relationship Between Traumatic Brain Injury and Alzheimer s Disease: Epidemiological Determinants, Their Health-Related Causes, and the Resulting Disparities
Abstract
Preliminary studies performed using data drawn from the Health and Retirement Study (HRS) showed that traumatic brain injury (TBI) is strongly associated with the risk of receiving a diagnosis of Alzheimer’s disease (AD) and AD-related dementias (ADRD) both for Veterans and non-Veterans, with Veterans facing relatively higher risk. However, the causes behind these relationships as well as the mechanisms by which they operate and influence veteran’s quality of life have not been identified. Two specific aims are planned to overcome this knowledge gap: Aim 1: Epidemiology of traumatic brain injury, Alzheimer’s disease, related dementia, and related comorbidities; Aim 2: Effects of modifiable risk factors, quality of life, and genetics. In Aim 1, we will define and identify distinct TBI-related subtypes that reflect differences in the types of injury received, subtypes ADRD, and their associations using individual Medicare and Veterans Affairs (VA) records. All estimates will be compared between the Veteran and non-Veteran subpopulations in the HRS. We will evaluate the extent to which time independent risk factors (e.g., race/ethnicity, gender, education, and genetics) modify previously identified effects. We will use an extended version of partitioning approach recently developed by our group in order to evaluate Veteran-civilian disparities in AD/ADRD risk as well as their prevalence and mortality. The 5%-Medicare data will be used in addition to the HRS-Medicare data to enhance statistical power of the estimates. In Aim 2, we will identify risk-related behavioral patterns (smoking, alcohol consumption, physical activity, adherence to treatment guidelines of significant comorbid diseases) and quality of life factors (income, wealth, depression, number of physical limitations, life-outlook) in Veterans and non-Veterans; compare their age-specific and age-adjusted prevalence; and evaluate the roles of these factors on the relationship between TBI and AD. Also, we identify trajectories of cognitive dysfunction by validated cognitive measures that could serve mediators of the effects of TBI on AD/ADRD and earlier predictor of AD/ADRD for civilian and Veteran subpopulations. The results will allow us to formulate strategies to aid in minimizing the risks of AD onset in post-TBI Veterans in terms of the new knowledge gained in Aims 1 and 2. The results will be validated using the Alzheimer s Disease Neuroimaging Initiative (ADNI)-DoD data. The application meets the formulated intent of the Convergence Science Research Award mechanism because it (i) focuses on Veteran-civilian disparities in TBI-associated AD/ADRD risk and uses innovative and accurate approaches for their evaluation (e.g., partitioning analysis); (ii) identifies and quantitatively estimates common risk factors (symptoms or deficits) of TBI and AD/ADRD; (iii) reveals how these risk factors work in increasing the risk of AD/ADRD, through identification of differences in these effects in civilian and Veteran subpopulations; and (iv) proposes strategies allowing to minimize the risks of AD onset in post-TBI Veterans. The application is aligned with the Overarching Challenge “Epidemiology” because it will provide comprehensive epidemiological analyses of the interrelationships between TBI and subsequent AD/ADRD for the Veteran and civilian communities. The application is also aligned with Overarching Challenge “Paucity of Research Resources” because our methods will allow for joint analysis of Medicare trajectories in 5%-Medicare and HRS-Medicare where only the latter contains the Veteran/civilian indicator. The application is partly aligned with Overarching Challenge “Quality of Life” because it will assess the effects of risk factors, thus allowing for formulation of strategies to aid in minimizing the risks of AD onset in post-TBI Veterans comparing to civilian subpopulations. The application is aligned with the following focus areas: (i) Epidemio
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010253
Entities
People
- Igor Akushevich
Organizations
- Duke University
- United States Army