Keith E. Whitfield - US grants

DESCRIPTION (adapted from investigator's abstract): This application intends to identify the sources of individual variation (genetic and environmental influences) in health among African-American twin pairs aged 65 years and older. The assertion is made that knowledge about African-Americans allows greater insight into the role of environment and genetics in aging among the greater populace. Using a twin-sibling research design, this research addresses 1) specification of the sources of genetic and environmental influences on health in older African-Americans, 2) proportions of genetic and environmental influences accounting for covariance between health and personality, cognition, mental health, and social factors, and 3) specification of the differences in the similarity of health of twins compared to other siblings. To address these questions, there are four (sic) major objectives: (1) identify a sample of 400 paris of same-sex aged African-American twins and 200 siblings of the aged twins who reside in North and South Carolina and Virginia from a national population-based registry developed by the Black Elderly Twins Study; (2) perform in-person interviews of African-American twins and their siblings to assess the following dimensions of later life: cognition, mental health, physical health, personality, and social variables; and (3) access Medicare records on health care utilization.

Conventional wisdom suggests that decline in cognitive functioning is a prevalent and pervasive aspect of the normal aging process for all older adults. However, research concerning intellectual abilities in late life shows that differential life experiences, personality factors, chronic illness, and poor health produce different patterns and sources of individual variation in cognitive aging. One of the single most influential factors on current and future cognitive functioning is educational attainment. A critical historical event that may have produced considerable variability in cognitive functioning was the racial desegregation of schools. This event was the impetus for variability in both the quantity and quality of educational experiences for African Americans. The variability in this history graded event may represent an important contributor to what now surfaces as variability in the cognitive functioning of adult African Americans. The purpose of the proposed pilot study is to examine the potential effects of desegregation and current contextual factors related to socioeconomic status on the cognitive functioning of adult African Americans. The study will address the following questions: 1) What is the relationship between cognition and socioeconomic status indicators, particularly educational attainment, in African Americans? 2) Do qualitative educational factors influence the relationship between cognitive functioning and educational attainment in African Americans? 3) What is the relationship among cognition, educational attainment and literacy in African Americans? These questions will be addressed with data from interviews with 200 African Americans between the ages of 50 and 65 who live in the Baltimore, MD, area. During the interview, they will be asked questions about the characteristics of the school(s) they attended. In addition, assessments of their cognitive abilities and functional literacy will be completed.

DESCRIPTION (provided by applicant): Longitudinal investigations of cognitive abilities in older adults have shown that even though most abilities decline with advancing age few individuals show decline on all abilities and decline at the same rate. This heterogeneity in change of cognitive functioning is related, in part, to differential life experiences, social factors, chronic illnesses, and poor health. There is substantial evidence that African Americans experience differential and increased exposure to chronic stressors, have higher rates for many chronic illnesses and self-reports of poor health, and have different life experiences as compared to Caucasian elderly. However, research on aging has only begun to explore the relationships between these factors and cognitive functioning in African Americans, while the lion's share of the previous research has focused on Caucasian elderly. It is this paucity of research on the causes and consequences of cognitive aging in African American elders that has lead to the proposed longitudinal investigation. Specifically, this study will address the following objectives: 1) Determine the rate of change in multiple cognitive abilities over a three year period in African American elders, 2) Determine the extent to which changes across cognitive abilities are correlated, 3) Explore the association between socio demographic characteristics and change in cognitive functioning, 4) Examine the extent to which health and changes in health over a thirty month period are associated with declines in cognitive competence, 5) Explore the extent to which social support serves to buffer loss in cognitive competence, 6) Investigate the how cognitive functioning and decline in cognitive performance is associated with losses in everyday functional competency. The proposed project will collect longitudinal data on 600 African Americans between 50-79 years of age. There will be two interviews during the project period with a 30 month interval between sessions. The interview will consist of measures of cognition and memory, health indices, psychological, and social variables. Understanding the trajectories of cognitive abilities and the factors that contribute to change and stability in African Americans has at least two important contributions: 1) Elucidate the dynamics of how cognitive function changes with age in a population at risk, 2) Improve our understanding of the significance individual factors hold as protective factors against or risk factors for decline in cognitive functioning.

Project Summary/Abstract The goal of this application is to identify patterns of perceived stress, active coping style, health status and genes that contribute to longevity observed within African American families. We will examine these factors using vertical and horizontal approaches by studying similarities between siblings and parent-child pairs. To this end, we have the following questions: 1) Do familial effects (genes and shared environments) create similarity in the patterns of perceived tress and coping within and across generations? 2) Does stress account for differences in patterns of longevity between families? 3) Do psychosocial factors like stress, coping, and discrimination account for differences in patterns of health status and longevity between families? 4) What role do genes play in patterns of stress and longevity? 5) Are there gene-environment interactions between genes associated with stress and longevity and environmental factors such as family financial adversity and discrimination? To address these research questions, we have planned five specific aims: 1) Collect data from 750 older African Americans on perceptions of stress, discrimination, coping style, health, personality and genetics from multi-generation families (parent-child and siblings). 2) Examine similarities and differences in stress and coping, and health status among sibling pairs and across generations within families. 3) Compare the health status of siblings concordant for higher stress and poorer coping to those with lower stress and better coping. 4) Examine genes associated with stress and longevity in comparisons of long lived families and short lived families and among sibling pairs. 5) Are there gene-environment interactions between genes associated with stress and longevity and environmental factors such as family financial adversity and discrimination? This project is novel and innovative in that it will employ a multi method approach to understand longevity. It will use a quantitative genetic approach, a molecular genetic approach, and a multi generation approach. To our knowledge, this is the first time all of these methods have been employed on one sample.