Center for Population Health and Aging (CPHA)

2024. Avshalom Caspi. The links between mental and physical disorders across the life course: A whole nation analysis .

By launching this project with nationwide registry data we will pave the way for a grant application of a three-nation study that will bring together physical health, mental health, and socioeconomic data across the life span (from birth to age 100) in three nations (New Zealand, Denmark, and Norway) for >14 million people. These three nations have unique nationwide data registries. We have already established the feasibility of working with the New Zealand and the Danish data. Our goal is to become sufficiently familiar with a new data resource from Norway, and to generate an initial publication, that will document feasibility for a grant application of a three-nation study. The three nations offer access to complementary nationwide health records, including prescription records, hospital records, and, in Norway, primary-care encounters.

Our aim is to identify the links between mental disorders and physical diseases in the population. To do so, we will leverage a unique data resource that to our knowledge is not available anywhere else in the world: every primary care health encounter over a 17-year period from 2006-2022 in Norway, where all residents are assigned a primary-care physician. By exploring the connections between mental disorders and physical diseases within primary care context, we strive to deepen our understanding of the interplay between mental and physical health, from childhood to old age. Using pilot grant funds, we will prepare and code the nationwide data from primary-care records, and also prepare an initial report which will serve as a ‘preliminary study’ for an extramural grant application.

Priority Research Areas: Determinants of Health, Well-Being and Longevity, Population, Economic and Health Forecasting

2024. Herman Pontzer. Allostatic Load and Cardiometabolic Health in a Rural Population.

This project directly examines foundations of lifelong health by testing hypotheses linking early life adversity and physiological (dys)regulation (allostatic load) to cardiometabolic health in adults. It also involves biodemography by integrating biological indicators of health into a life course perspective to examine how the interactions between life events and physiology contribute to population health disparities and mortality differentials. Accordingly, this project engages life course studies through focusing on the cumulative effects of early life experiences on long-term health consequences. The project’s goals include advancing our understanding of how chronic stress influences health across an individual’s health and lifespan, and how these relationships impact differences in population health.

The Great Smoky Mountain Study (GSMS) provides a unique opportunity to investigate longitudinal effects of early life experience and adversity on cardiometabolic health over the life course. Previous work with GSMS has focused on psychosocial and environmental sources of adversity. With banked dried blood spots for all participants beginning at their enrollment into the study, there are numerous opportunities to expand these analyses to examine biomarkers of physiological stress and dysregulation, including allostasis. This project is a first step in this direction. Results will provide pilot data for grant proposals examining physiological measures of early life stress, their changes over the life course, and their association with adult health outcomes.

Priority Research Areas: Determinants of Health, Well-Being and Longevity, Biology, Genetics and Demography of Aging

2024. M. Giovanna Merli. Data Collection Innovations to Study the Health of African Immigrants in the United States.

The topics and methods featured in this study are consistent with DUPRI’s support for data innovations and with the signature themes of the P30-funded CPHA and P2C-funded DPRC (demography of health, life course studies, foundations of lifelong health and interconnected social systems and population health). This project is the first in a collaboration among the following teams:
(1) the Duke-UNC team composed of Giovanna Merli (Professor of Public Policy at Duke), Ted Mouw (Professor of Sociology at UNC) and colleagues, who have invested significant effort in the empirical testing and evaluation of an innovative link-tracing sampling design, Network Sampling with Memory (NSM), which traces the links (social ties) of respondents to recruit subsequent waves of respondents into the sample according to probability sampling principles. Merli and Mouw have successfully tested this approach among Chinese immigrant populations in the US, Africa and Europe as well as Mexican immigrants in the US. They have shown that NSM is able to generate representative samples of immigrant populations, when compared with the American Community Survey, and that peer referral driving sample recruitment increases response rates; (2) the University of Pennsylvania team composed by Irma Elo, Professor of Sociology and Jere Behrman, Professor of Economics (3) the University of Ghana team led by Ayaga Bawah, Associate Professor and Director of the Regional Institute for Population Studies at the University of Ghana.
The Penn and Ghana teams have significant expertise in the study of immigrant health and mortality, African health, human resources, economic demography, incentive systems and household behaviors, as well as in the design and conduct of longitudinal data collections in Africa and other low and middle income areas. These two teams have already worked together on a small pilot study of a convenience sample of Ghanaian immigrants in Philadelphia.

The purpose of this collaboration is to extend the NSM methodology to recruit binational samples of Ghanaian migrants to the U.S. to better understand the impact of migration on the health and wellbeing of African migrants and their families at both origin and destination. The Duke-UNC’s team successfully evaluated NSM with support from grants from NICHD and France National Research Council. We are now planning an NIH R01 grant application to apply and extend this tested methodology to recruit a binational sample of Ghanaian migrants that captures the contexts at origin and destination and to use the peer-referral approach embedded in NSM techniques to follow members of the recruited sample over time. A DUPRI pilot award would help us collect preliminary data and test the feasibility of collecting the network data required by the implementation of NSM among Ghanaian migrants. The new R01 grant application will thus follow from previous NIH investments in this methodology, which would increase the probability of success.

Priority Research Areas: Migration and health

2023. Jen'nan Read. Implications of White Diversity for U.S. Black-White Health Disparities.

The overarching goal of this project is to examine how demographic changes in the ethnic origins of whites impact knowledge on U.S. racial disparities in health over time. Specifically, the project will decompose non-Hispanic whites by nativity and region of birth using nationally-representative data from the National Health Interview Survey and the American Community Survey and then replicate studies on black-white health disparities. The replication will first use the standard aggregate white category in comparisons to blacks and then substitute alternative definitions of whites that isolate those of western European descent from those of eastern European, Middle Eastern and North African descent.

Findings from this study will have implications across DUPRI’s priority areas and contribute to ongoing debates on potential revisions to federal standards on race and ethnicity. The common practice across population health sciences is to treat Whites in the aggregate in studies of U.S. racial inequality, particularly research that focuses on gaps in resources and health outcomes between groups. Studies that focus on within-group diversity among Whites, including my own, are illustrative for identifying vulnerable subpopulations that are masked by the aggregate category. However, they do not address whether changes in the composition of whites over time impact knowledge on intergroup racial inequalities between blacks and whites. Answers to this question would inform research on racial inequality and guide policies that seek to alleviate them.

Priority Research Areas: Health Trends and Disparities

2023. Hanzhang Xu. Characterizing Caregiving Networks among Persons with ADRD in a Global Context.

The proposed study is consistent with two priority areas at CPHA as indicated above. First, our study will identify the caregiving networks shared by persons with Alzheimer’s disease and related dementia (ADRD). Some of the caregiving networks likely will include family members across different generations. For example, in China, the cultural expectation of caregiving within the home/family (e.g. filial piety) may contribute to the multigenerational living environment. Therefore, the proposed project is consistent with the intergenerational studies priority area. Furthermore, while the current study will focus on the heterogeneity of caregiving networks and factors associated with it, our ultimate goal is to assess whether certain caregiving networks are associated better well-being, personhood, and quality of life among persons with ADRD. As family and friends are vital to the health and well-being of persons with ADRD, this project’s focus on linked lives is also consistent with the life course studies priority area.

The PI has been working closely with the Worldwide Elements To Harmonize Research In long-term care liVing Environments (WE-THRIVE) consortium since 2018. In brief, this consortium aims to establish common data elements (CDE) that are relevant to person-centered long-term dementia care. Recently this consortium was invited by the NIA to submit a P01 application that focuses on advancing the identification and use of dementia CDEs that can serve as the springboard for numerous additional studies of the structure, functioning, quality, and equity of dementia care. This proposed project will provide much needed preliminary evidence for one of the P01 projects (R01 equivalence) that focuses on profiling dementia caregiving networks using existing data. This line of work is closely aligned with several NIA’s special interests: ADRD, family caregiving, HRS and HRS International Family of Studies.

Priority Research Areas: Consequences of U.S. and Global Aging, Determinants of Health, Well-Being and Longevity

2023. Matthew Dupre. Racial Differences in Age-Related Hearing Loss in Middle-Aged and Older Adults.

Decades of research has documented racial differences in the health and well-being of older adults in the United States. However, much less is known about the life course patterning and predictors of racial differences in hearing loss among U.S. older adults. Evidence from population-based studies indicates that Black Americans have a 40-70% lower prevalence of hearing loss and better pure-tone thresholds compared to White Americans. The reasons for these racial differences in hearing sensitivity are not well understood and appear paradoxical in the context of the large literature on racial disparities in health. Drawing on the life course perspective and biodemography, Black adults may have greater age-related hearing loss than previously observed, but these racial differences may be obscured by failing to account for the life course patterning of hearing loss and the accumulation of risks that Black adults face. Research shows that Black adults experience greater lifetime exposure to risk factors for hearing loss than White adults. For example, Black individuals are much more likely to work in jobs that place them at increased risk for noise-induced hearing loss and live in areas exposed to greater levels of environmental noise pollution or infectious diseases associated with hearing loss (e.g., cytomegalovirus). However, previous research has not examined how the accumulation of a wide range of social, behavioral, and/or physiological factors may contribute to age-related patterns of hearing loss among White and Black older adults. Moreover, most studies that have examined hearing loss are primarily limited to White populations or do not disaggregate Black populations from other minority racial/ethnic groups (i.e., focusing on “non-White” groups).

To date, there is limited and conflicting evidence to inform the development of clinical and public health interventions to address hearing loss among racial minorities. This pilot project will lay the groundwork to begin addressing this gap by leveraging multiple data sources to understand how a wide array of factors may be contributing to age-related patterns of hearing loss among White and Black middle-aged and older adults. Results from this pilot project will be used to develop an NIH Diversity Supplement (PA-21-071) to examine the implications of age-related hearing loss for differences in hospitalizations in older adults and an NIH/R21 proposal to develop the preliminary evidence needed to support a tailored intervention to improve hearing healthcare among racial minorities.

Priority Research Areas: Cognitive Aging and the Demography of Dementia, Determinants of Health, Well-Being and Longevity

2022. Charles Nunn. Quantifying the gradient of market integration in relation to health across the life course in northeast Madagascar.

The pilot research engages with (1) “Foundations of Lifelong Health” by investigating the impact of interactions among biological, behavioral and environmental factors on human health throughout the life course, and (2) “Interconnected Social Systems and Population Health” by considering how
social connections influence aging and health. The pilot research will form a foundation for building a rich understanding of ongoing market integration in the Sava region of northeast Madagascar where people are transitioning from a lifestyle based on subsistence farming to a lifestyle based on
market activities, including buying and selling goods. This research will further understanding of the effects of economic change on health across the lifecourse.

The proposed pilot work will help secure external funding in three main ways: (1) by developing methods to quantify market integration that are appropriate for the cultural, economic, and social context of the area (northeast Madagascar); (2) by expanding our existing research to capture a wider spectrum of variation in market integration across villages; and (3) by conducting initial tests that investigate whether market integration covaries with age, health outcomes, and contact patterns in the region. Previous work studying health in three villages has revealed that agriculturalists are
increasingly farming a key cash crop (vanilla). This work has demonstrated variation in market integration within these villages; we also expect to document variation across villages, which range from subsistence farmers far from transportation networks to hubs of market activity along major
roadways. In the context of larger grant applications (R21s or R01s), we will propose to investigate how market integration influences infectious disease exposure, cardiovascular disease, sleep and health disparities, social networks and health, and stress across the life course. We anticipate that
initial funding applications in the next 24 months will focus on the first two of these topics and incorporate interactions between age and market integration.

Priority Research Areas: Population, Economic and Health Forecasting, Determinants of Health, Well-Being and Longevity

2021. Elizabeth Gifford . Characterizing Accelerated Aging in Veterans of the Gulf War using Epigenetic Biomarkers.

Gulf War illness (GWI) is a chronic multisymptom illness (CMI) like fibromyalgia, irritable bowel syndrome, and chronic fatigue syndrome. GWI affects an estimated 25-32% of veterans who were deployed in support of the first Gulf War (1990-91) who continue to experience a host of persistent and reoccurring symptoms (e.g., fatigue, pain, rashes, and gastrointestinal issues) that cannot be explained by other diagnosed medical conditions. An unanswered question for Gulf War veterans is whether or not individuals who experience GWI are also at- risk for experiencing accelerated aging as evidenced by older “epigenetic clocks” and younger age of onset for various chronic conditions. The overarching aim of this pilot is to leverage rich data collected on Gulf War era veterans including self-reported survey data, GWAS (genome wide association study) data, and electronic medical records to create generalizable knowledge regarding aging and disease progression. Specifically, utilizing the Gulf War Era Cohort and Biorepository data repository, this pilot will develop four estimates of epigenetic physiologic age for participants of the Gulf War Era Cohort and Biorepository in support of testing the following hypotheses: (1) Epigenetic age estimates will be higher in Veterans with GWI compared to those without GWI; (2) Epigenetic age estimates will be higher in Veterans with chronic health conditions compared to those without chronic health conditions; (3) Epigenetic age estimates will be higher in Veterans with psychosocial stress, as measured by post-traumatic stress disorder (PTSD).

Priority Research Areas: Biology, Genetics and Demography of Aging, Health Trends and Disparities

2021. Tyson Brown . Structural Racism and Trajectories of Disease and Disability in Later Life.

Health inequities along racial lines are broad and deep. Black Americans have a greater prevalence and severity of an array of illnesses, including chronic diseases and disability. While the vast majority of research on racial inequalities in health has focused on the role of individual-level factors such as socioeconomic resources (e.g., education, insurance, income, and wealth), a nascent line of research has begun to examine how health inequities are shaped by contextual factors stemming from structural racism (SR)—i.e., systemic racial exclusion from power, resources, opportunities, and well-being due to societal policies, practices, ideologies and institutions. Prior research has not examined whether racialized socioeconomic inequality is a mediating mechanism linking macro-level structural racism and individual-level health trajectories among older adults. This information is critical for understanding and addressing pathways through which SR affects health in later life. To address these critical gaps, this pilot will create and disseminate a dataset on SR, spanning economic, social, political, and judicial domains as well as over time between 2000 and 2020. This data resource will be a valuable tool for the research community to efficiently build the knowledge base on how SR shapes population health and aging processes. Second, the pilot will provide novel information about the longitudinal relationships between SR and trajectories of health. Finally, the pilot will test the following: a) whether higher levels of SR exposure are predictive of worse health trajectories (levels and rates of accumulation of chronic diseases and disability), b) the extent to which cumulative (and changes in) exposure to SR impacts trajectories of health, and c) whether there are lagged effects of SR exposure on chronic disease and disability trajectories.

Priority Research Areas: Health Trends and Disparities, Determinants of Health, Well-Being and Longevity

2021. Gregory Samanez-Larkin. Adult age differences in learning and decision making related to differences in sensitivity to different types of reward.

Neuroscientific research on decision making and aging has focused almost exclusively on monetary incentives. Despite evidence for intact processing of and motivation by monetary gains in old age, preserved function does not extend to learning-based decision making where these incentives must be applied. Here older adults learn more slowly from monetary gains and losses compared to younger adults. These age deficits in learning have been linked to the structure and function of frontostriatal brain circuits, and some studies suggest that enhancement of this neural network via pharmacological increases in dopamine levels selectively improves reward learning in older adults. Although age differences in incentive motivation have been suggested to be due to motivation to maximize well-being (i.e., based on socioemotional selectivity theory), almost no studies have examined age differences in social incentive processing. An interesting possibility is that social incentives may provide a non-pharmaceutical and non-invasive enhancement of frontostriatal networks thus improving learning in old age. The goal of the proposed pilot studies is to examine adult age differences in behavioral and neural sensitivity to social and monetary incentives and examine the behavioral and neural effects of these incentives on learning-based decision making. For the proposed studies we have developed cognitive tasks that will investigate subjective emotional responses during anticipation and receipt of social and monetary incentives (Aim 1), neural sensitivity to the anticipation and receipt of social and monetary incentives (Aim 2), and learning from probabilistic social and monetary outcomes during decision making (Aim 3). One behavioral pilot study (Study 1) and one behavioral and neuroimaging pilot study (Study 2) will be conducted.

Priority Research Areas: Cognitive Aging and the Demography of Dementia, Disability, Health Care and Long-Term Care

2021. Terrie Moffitt . Psychological and mental health determinants of COVID-19 vaccine hesitancy and vaccine resistance.

This pilot aims to deliver a comprehensive psychological description of groups who differed in their vaccine intentions in the months just before vaccines became available to them utilizing a cohort on all 1037 births (1972-1973) in one city from the Dunedin Study in New Zealand. Public health professionals aspire to tailor pro-vaccination messaging to the values, motives, lifestyles, and background of people who are hesitant or resistant toward vaccination. This tailoring has called for a “marketing approach” to messaging. However, there is a wide social gap between highly-educated public health professionals and most unvaccinated citizens, who tend to be secondary-school educated, or less. This gap impedes effective messaging. For example, prior US surveys report that unvaccinated individuals tend to be Republicans, or southerners, or not college graduates, but these are crude proxies for people’s actual beliefs, attitudes, preferences, cognitive abilities, and motivations. This pilot harnesses psychologically rich prospective data from a 5-decade longitudinal cohort study to provide insights about the personal psychologies associated with vaccine-hesitance and vaccine-resistance, and whether those personal psychologies emerged early in life and are longstanding. Dunedin cohort members have reported whether they definitely or probably intended to be vaccinated ; definitely or probably did not intend to be vaccinated, or did not know enough to decide. The pilot will compare these 3 groups on prospective antecedents of vaccine intentions, including: (1) adverse childhood experiences; (2) adolescent personality and locus of control over health; (3) cognitive abilities and health knowledge and comprehension of health concepts; and (4) detailed mental disorder histories.

Priority Research Areas: Determinants of Health, Well-Being and Longevity, Health Trends and Disparities

2021. V. Joseph Hotz . Assessing New Data Source for Measuring Income Volatility to Study Its Relationship with Mortality in the U.S.

This pilot will assess the use of data from a commercial consumer database on all households in the U.S. to construct reliable measures of the volatility of household income. If successful, the resulting data will be used to assess the relationships between income volatility and mortality in the U.S. and how that relationship varies by race/ethnicity, age and gender of heads of households in the U.S. Study of the latter relationship has been hampered by the lack of availability of samples of households in the U.S. that contain longitudinal data on income and that are of sufficient size to form reliable estimates for all or most counties in the U.S. for different race/ethnic, age and gender groups. If this assessment of the measures of income volatility produced by this data source are positive, others will be able to conduct the first large-scale assessment of the role that income volatility may have played in explaining the recent declines in life expectancy for working age adults in the U.S. and may explain differences in mortality rates by regions of the U.S., and disparities in mortality across racial and ethnic groups.

Priority Research Areas: Determinants of Health, Well-Being and Longevity, Consequences of U.S. and Global Aging

2020. Susan Alberts . Early adversity in a wild primate model: Physiological mediation and social mitigation.

Adversity in early life has far-reaching effects on health, well-being, and survival in adulthood, especially when multiple adverse events co-occur. This association is seen not only in humans, but also in captive and wild nonhuman primates. Captive primates exposed to nutritional deficits or maternal neglect show decreased survival in adulthood compared to control animals. Wild baboons who experienced multiple forms of early adversity show reduced adult survival compared to unaffected individuals. Studies of humans and captive animals suggest that immune processes may mediate the effects of early adversity on survival. Early social and physical adversity in humans and captive animals is associated with increased risk of cardiovascular disease, diabetes, mental illness, and allostatic load. In several studies of humans, early-life trauma is also associated with chronic inflammation or heightened inflammatory response to an immune threat. Population-based, prospective, longitudinal studies with multiple repeated measures of adult traits are necessary to fully understand the developmental and physiological underpinnings of early adversity. Innovation. This pilot offers a solution to these challenges by using existing prospective, full life-course data, with real-time, direct observations of both early life adversity and adult sociality, as well as repeated noninvasive measures of adult immune function measured in biological samples that have already been collected. Investigators anticipate the development of a novel dataset that will generate a large number of repeated measures of immunity for each subject in our study; this pilot will be one of the first to measure baseline and acute inflammation in serum from wild animals, a method that may be useful for other wild animal and human research. It will also be one of the first to leverage repeated measures within subjects to quantify baseline versus acute inflammation levels

Priority Research Areas: Determinants of Health, Well-Being and Longevity

2020. Herman Ponzer . The Daasanach pastoralist population of northern Kenya: A model for healthy aging—specifically the avoidance of non-communicable disease and frailty.

Small-scale subsistence populations like the pastoralist population of northern Kenya, the Daasanach, have remarkably low prevalence of age-related frailty and cardiometabolic disease, diseases strongly associated with aging and responsible for the vast majority of morbidity and mortality in the U.S. and other industrialized populations. This pilot will investigate which aspects of lifestyle (physical activity, diet, etc.) promote healthy aging among the Daasanach. Two aspects of Daasanach life are of particular relevance to the study of aging. First, like many rural populations across the developing world, the Daasanach are moving from active traditional lifestyles to more sedentary, market-integrated village life. Second, the Daasanach have a largely animal- based diet (blood, milk, and meat). The Daasanach are at the epicenter of the epidemiological transition. Understanding lifestyle changes affecting their life course will help shape strategies to promote healthy aging and other positive health outcomes for them and for other populations in transition and post-transition. This pilot takes advantage of a societal transition in a pastoral environment to capture biosocial processes over the life course that lead to differential aging

Priority Research Areas: Consequences of U.S. and Global Aging