Recent Social Disparities and Health (C2S) Research


Social Disparities, Stress, and Health

adam-emma-talk.jpg
IPR psychobiologist Emma Adam has found that discrimination is
associated with chronic stress, with adolescent experiences
having particularly strong effects on adult stress biology.

Discrimination Affects Stress, Health
Does being exposed to discrimination affect health? IPR health psychobiologist Emma Adam and her colleagues are examining 20 years of data, gathered from adolescence through young adulthood, in a project with funding from the National Institutes of Health (NIH). The data include exposure to race-related stressors, as well as measures of family functioning, racial and ethnic identity, and coping. Adam is examining this data with a wide range of stress-sensitive biological measures in young adulthood, including gene expression relevant to the regulation of biological stress. Results indicate that participants with higher perceived discrimination have lower overall cortisol levels and flatter cortisol diurnal rhythms, which are associated with chronic stress. Experiences of discrimination during adolescence have particularly strong effects on adult stress biology. Adam also finds that histories of discrimination help to explain racial and ethnic differences in cortisol rhythms. However, the presence of a strong ethnic and racial identity in adolescence, and particularly in early adulthood, is associated with better-regulated stress biology and higher levels of academic attainment.

Socioeconomic Status and Asthma
IPR health psychologists Edith Chen and Greg Miller are leading work on the intergenerational health effects of economic hardship. With IPR faculty adjunct Madeleine Shalowitz of NorthShore University HealthSystem, the researchers examine whether parents’ childhood socioeconomic status (SES) is associated with asthma in their children. The NIH-funded study of 150 children aged 9–17 finds that those with parents who grew up in households with lower SES were more likely to have poorer asthma control, compared with those whose parents grew up under better socioeconomic conditions. The researchers focus on one potential explanation: family relationship stress. They note that parents who grew up in low-SES households were more likely to experience frequent family conflict and harsh parenting as children, and they were also more likely to have less supportive and trusting relationships with their own children. Greater family stress is, in turn, associated with poorer control of childhood asthma. Chen, Miller, and their colleagues suggest that efforts to ameliorate asthma disparities need to go beyond improving families’ current socioeconomic circumstances to addressing children’s family environments and their potential effects across generations. The results are published in the Journal of Allergy and Clinical Immunology. Chen is the John D. and Catherine T. MacArthur Professor of Psychology, and Miller is the Louis W. Menk Professor of Psychology.

Health Effects of the Great Recession
Some of the highest rates of illness and death from cardiovascular disease in the United States are found among lower-income African American communities in the rural Southeast. Research suggests this disparity originates early in life, and it might reflect the influence of socioeconomic forces acting on behavioral and biological processes that accelerate the progression of cardiovascular disease. Miller and Chen and their University of Georgia colleagues test this hypothesis in the Journal of the American Heart Association. The researchers followed 328 African American youth from rural Georgia before and after the Great Recession. They measured the youths’ glucose levels, blood pressure, and waist circumference, all of which increase the risk for heart disease, stroke, and diabetes. The researchers discover that the prevalence of these risk factors, or metabolic syndrome, varied depending on how the Great Recession affected families’ economic status. Metabolic syndrome prevalence was lowest for youth whose families continued to have low incomes throughout the recession, but it rose to more than 21 percent for youth in families who slipped from lower-income to poverty status during it. The highest rate of 27.5 percent was among youth whose families began the recession in poverty and sank even deeper into it afterwards. The results suggest that broader economic forces shape cardiometabolic risk in young African Americans, potentially exacerbating disparities already present. The NIH supported the research.

The Health Costs of Family Stress
Family stress can lead to worse health outcomes, including for adolescents who experience many demands in their family life. Chen investigates under what circumstances family demands might have a physiological cost. In Health Psychology, she looks at two potential moderators between frequency of family demands and adolescents’ inflammatory profiles: the closeness of the teens’ relationships with their families and how often teens provided help to their families, such as doing chores or caring for siblings. For the study, 234 youth aged 13–16 filled out a daily diary and were interviewed about their family relationships. Chen finds that more frequent demands from family predicted higher levels of inflammation. Family closeness moderated this relationship, as frequent demands proved to be more physiologically detrimental when adolescents were close to their families. How frequently the teens provided help also moderated the relationship, with more frequent demands predicting worse inflammatory profiles when adolescents helped out more with the family. The results build on previous work to show how family pressures can affect health.

Greg Miller and Edith Chen
IPR health psychologists Greg Miller and Edith
Chen, shown here in their lab, are investigating
how socioeconomic status affects health,
including the risk for cardiovascular disease and
metabolic syndrome.

Metabolic Health Disparities
A quarter of the world’s population has metabolic syndrome, which includes high blood pressure, high blood sugar, and high cholesterol. Researchers have shown that being lower on the socioeconomic ladder is associated with a higher risk for metabolic syndrome. In Psychosomatic Medicine, Miller and Chen examine how economic disadvantage early in life—even if an individual later moves up the socioeconomic ladder—is related to a higher risk of metabolic syndrome in mid-adulthood. They determine that early-life SES affects risk. On average, individuals with low childhood SES were nearly twice as likely to meet the criteria for metabolic syndrome at midlife than those with high childhood SES. However, the researchers do not find a significant effect for SES at the time when metabolic syndrome is measured. Miller and Chen suggest that early childhood might be an opportune time to target interventions aiming to reduce the risk of metabolic syndrome across a person’s lifespan.

How Sleep Timing Affects Diabetes
Research has shown that not getting enough sleep can increase metabolic disease risk. Does sleep timing also affect risk, given the potential impact on circadian rhythms of metabolic function? Neurologist and IPR associate Kristen Knutson investigates whether such a link exists in a study of more than 13,000 Hispanic adults. Knutson and her colleagues discover that going to sleep later is associated with higher estimated insulin resistance, which can contribute to developing diabetes. They also find that other associations between sleep timing and metabolic measures might depend on age. Among participants younger than 36, going to sleep later was associated with a lower body mass index, lower fasting glucose, and lower hemoglobin A1c—all of which are linked to a lower risk of diabetes—but the opposite was true for older participants. Knutson and her colleagues explain in Sleep that behavioral interventions addressing sleep timing might add to existing approaches for preventing and managing diabetes, which disproportionately affects Hispanics in the United States.

Breast Cancer Screening Beliefs
Cancer is the leading cause of death among Chinese Americans, and breast cancer is the most frequently diagnosed cancer among Chinese American women. Despite this, Chinese Americans have low rates of mammography screening. To investigate Chinese American women’s attitudes toward screening and healthcare barriers, health disparities scholar and IPR associate Melissa Simon conducted six focus groups among Chinese-speaking adult women aged 45 and older. The women expressed a range of opinions about the importance of breast cancer screening. Among those who did not believe it was important, reasons included not feeling sick and perceived harm from mammographies. The women also highlighted barriers to screening, including language differences, transportation issues, and not wanting to burden their adult children. Simon and her colleagues suggest in The Journals of Gerontology that patient navigators might help improve screening rates by providing interpreter services and making appointment reminder calls. Community health workers might also help meet the health needs of older Chinese American women, as participants’ limited knowledge of breast cancer causes and symptoms shows there is a need for more accessible cancer education. Simon is the George H. Gardner, MD, Professor of Clinical Gynecology.

Wealth and Health Among Hispanics
Is there a relationship between wealth and health among Hispanics? IPR associate Frank Penedo, a professor of medical social sciences, and his colleagues examine whether there is a link between SES and risk factors for cardiovascular disease in the Hispanic and Latino population. They use data from 4,971 Hispanics and Latinos aged 18–74. The researchers find no overall association between wealth and hypertension, high cholesterol, or obesity. Breaking down the data further, they find more mixed results. Women in the middle of the wealth distribution were less likely to have high cholesterol or be obese. Wealthier Central Americans were less likely to be obese while wealthier Puerto Ricans were more likely to be obese. The researchers note that future studies should incorporate more robust measures of wealth to help clarify their results and determine the relationship between wealth and health. Penedo is the Rosewell Park Professor.

Mexican American Mental Health
Mexican American youth are more likely to experience mental health problems such as depression and anxiety than their white peers. Do the experiences of Mexican American adolescents receiving treatment also differ? IPR anthropologist Rebecca Seligman is investigating this using both ethnographic and quantitative methods, examining how culture and ethnicity matter to Mexican American patients, how healthcare providers treat Mexican Americans in mainstream mental healthcare settings, and the experiences and responses to treatment of youth who receive care. In the study that received funding from the William T. Grant Foundation, Seligman seeks to assess which factors most strongly influence quality of care outcomes, including patient satisfaction, adherence to treatment, and retention. The findings have the potential to improve clinical practices and promote better social, emotional, and behavioral outcomes for already disadvantaged Mexican American youth struggling with psychological distress.

HIV/AIDS and Transformation
In her forthcoming book, Remaking a Life: How Women Living with HIV/AIDS Confront Inequality (University of California Press), IPR sociologist and African American studies researcher Celeste Watkins-Hayes examines how women remake—not just rebuild—their lives after trauma. Watkins-Hayes draws on interviews with more than 100 Chicago women living with HIV/AIDS, as well as her discussions with nationally recognized advocates, to position the AIDS epidemic as a lens to understand how people radically improve their social well-being. She outlines a theory of transformative projects, in which individuals fundamentally shift how they conceptualize, strategize around, and tactically address struggles related to inequality. Watkins-Hayes also traces the unique safety net that has enabled HIV-positive women to launch successful transformative projects. She argues that the HIV/AIDS service and healthcare infrastructure offer important lessons for how advocates and institutions might think about assisting other socially and economically marginalized populations, not just those living with HIV.

Social Support Mediates Viral Load
Having friends and family to turn to has been shown to protect health. Behavioral scientist and IPR associate Linda Teplin examines whether this extends to HIV/AIDS among men who have sex with men. In AIDS Care, Teplin and her colleagues use longitudinal data from men using antiretroviral therapy enrolled in the Multicenter AIDS Cohort Study between 2002 and 2009. They assess characteristics of social support and the effects of social support on HIV viral load. The researchers discover that men who had higher levels of social support had greater viral load suppression and lower viral load means. However, African American and Hispanic men who have sex with men reported lower social support than their white counterparts. Teplin, the Owen L. Coon Professor of Psychiatry and Behavioral Sciences, explains that interventions to boost social support could particularly benefit men of color who are HIV-positive.

Intergenerational Perspectives on Health Disparities

Economic Hardship and Birth Outcomes
Previous research suggests that the health consequences of economic hardship can be passed across generations, with some of these disparities thought to be passed to children during pregnancy. In Brain, Behavior, and Immunity, Miller tests this hypothesis by investigating whether women exposed to economic hardship during childhood show higher rates of adverse birth outcomes. With Adam, IPR anthropologist Thomas McDade, and IPR associate and obstetrician Ann Borders, Miller finds that mothers who experience economic hardship in childhood were more likely to deliver their babies preterm. Their babies also weighed less at birth, were more likely to be small for their gestational age, stayed in the hospital longer, and were more likely to be admitted to a special care nursery. The researchers also identify multiple behavioral and biological mechanisms associated with childhood hardship and pregnancy outcomes. For example, childhood disadvantage predisposes women to express higher levels of interleukin-6 during pregnancy, which accelerates gestation and can also lead to premature labor. McDade is the Carlos Montezuma Professor of Anthropology.

Reducing Prenatal Stress
Lauren Wakschlag, an IPR clinical and developmental psychologist, is seeking to improve trajectories for child neurodevelopment by reducing maternal stress during pregnancy. The “Promoting Healthy Brain Project,” which also includes clinical and developmental psychologist and IPR associate Amélie Petitclerc, involves a randomized controlled trial with 200 mothers and their babies, following them from the second trimester through the first year of their children’s lives. Wireless wearable health sensors will measure the mothers’ heart rate, and smartphone surveys will measure when mothers are experiencing stress in a typical day. Mothers will receive a one-on-one stress reduction intervention, the “Mothers and Babies” course, in addition to their usual prenatal care. When the heart rate and survey data indicate that mothers need additional support, the project will send extra stress reduction messages and interventions via their smartphones. Researchers will also observe infant neurodevelopmental trajectories at birth, at 6 months, and at 12 months. Their overarching goal is to improve child neurodevelopment by reducing maternal stress in real time.

Social Stratification, Stress, and Health
McDade is investigating the links among social stratification, stress, and health. He is continuing research on the impact of financial debt on both mental and physical health. In 2013, McDade was part of a study that was the first to examine the effect of debt on physical health. The results, published in Social Science and Medicine, found that a higher debt-to-asset ratio was associated with higher perceived stress and depression, higher diastolic blood pressure, and worse self-reported general health. A new project, with funding from the National Institute of Child Health and Human Development, will examine how housing and neighborhood quality affect child health. Both studies build on McDade’s recent analyses of data from the National Longitudinal Study of Adolescent Health to investigate how socially patterned environments in infancy contribute to social disparities in adult health outcomes.

Income and Cognitive Development
IPR researchers have cast doubt on a widely-held belief that connects family income with cognitive development. A well-known theory holds that genes play a larger role in brain development for children from advantaged environments than in those from poorer backgrounds. However,
Figlio, Karbownik, Stanford sociologist Jeremy Freese, and University of Florida pediatrician Jeffrey Roth use matched birth and school records from Florida, finding that family income does not necessarily mitigate the effects of genetics on cognitive outcomes. They note that children from higher socioeconomic backgrounds have better cognitive outcomes on average than those from families with a lower SES, but genetics appear to matter just as much for both groups. The results, published in the Proceedings of the National Academy of Sciences, indicate that a full understanding of how genes interact with the environment to influence cognition is more complex and elusive than previously supposed.

Early Environments on Health Trajectories

Early Life Infection and Adult Health
Those who suffer many infectious diseases while growing up have shorter lifespans, suggesting the possible lingering influences of early life exposures. Exactly how early life infection influences later illness and death is unknown, however. In the American Journal of Human Biology, Kuzawa examines whether the shortening of telomeres could be a partial answer. Telomeres—the repeating DNA sequences at the ends of chromosomes—are an important molecular marker of aging. Using data from the Cebu Longitudinal Nutrition and Health Survey in the Philippines, Kuzawa and his collaborators link adults’ blood telomere length to early life data on infections. They find that a higher burden of diarrheal illness in infancy predicts shorter adult telomere length
in adults. This association was strongest for infections experienced from 6–12 months, which is when infants are typically weaned off breast milk and start to crawl and walk. This period is the first time pathogens tend to be introduced en masse without the immune-protecting effects of breast milk. Kuzawa’s results suggest that telomeres are a pathway by which early life environments and health might influence adult disease.

Brain Energy Needs in Childhood
Kuzawa and his colleagues previously discovered that the brain’s energy use peaks at 4–5 years of age, requiring twice the glucose that the adult brain needs. This peak in brain energy needs is not due to brain growth, but to a rise in the rate of energy use by neurons, which is temporarily increased during childhood as part of the normal process of learning and brain development. Kuzawa is currently assessing the feasibility of using a new, noninvasive imaging technique for measuring brain energy use in children as they age. The brain’s need for energy at 4–5 years old is so strong that it appears to divert energy
from body growth: There is an inverse relationship between body growth and brain energy use during infancy and childhood. Furthermore, the age when brain energy use is greatest is also the age when body growth rate is at its slowest. This suggests that young children’s healthy cognitive development might be particularly sensitive to the adverse effects of nutritional stress. Kuzawa notes that new approaches to interventions in young children could optimize healthy brain development.

Fathers and Testosterone
In previous research, Kuzawa has shown that men are biologically attuned for childcare: Becoming a father leads to a drop in testosterone that is believed to help men focus on raising their children. However, less is known about whether this decline in testosterone influences outcomes like relationship stability or child development. With support from the NSF, Kuzawa is addressing these questions using data and samples on 908 men along with their spouses and children. Kuzawa will compare hormone levels with detailed reports of men’s familial, professional, and social behaviors, as well as with outcomes related to child well-being and family relationships. In one aspect of this project, Kuzawa’s team examined a part of the gene that provides instructions for making the androgen receptor protein, which might influence an individuals’ “androgenicity.” Men with a low androgenic profile are at increased risk of depression, which could change family dynamics such as marriage stability and parenting. In Hormones and Behavior, Kuzawa and his colleagues find that men with intermediate androgenicity levels were most likely to be in stable relationships over the study’s more than four years. As fathers, they were also more involved with childcare.

Thomas McDade and Chris Kuzawa
IPR biological anthropologists Thomas McDade
(left) and Christopher Kuzawa (right), with IPR
health psychologist Greg Miller, have discovered
that environmental conditions early in develop-
ment can cause inflammation in adulthood.

Testosterone Transfer Among Twins
In collaboration with
Kuzawa and IPR research associate Krzysztof Karbownik, IPR education economist David Figlio is investigating how female twins are affected in utero when exposed to testosterone from their male twin. The researchers tracked all births in Norway over 10 years, following more than 12,000 twins for more than 30 years. They find that females with a male twin have substantially lower graduation and college attendance rates. They are also less likely to marry, have lower fertility, and have reduced lifetime earnings compared with women with a female twin. These effects persist among women whose twin died soon after birth, illustrating that the effects are likely due to prenatal testosterone transfer rather than to being socialized with a male twin.
The research is the first to address the long-term impacts of testosterone transfer among twins by following a full national population with objectively measured outcomes from the fetal stage into adulthood. Figlio is the Orrington Lunt Professor.

Mind-Body Processes and Health Outcomes
Seligman is also continuing theoretical work on mind and embodiment that seeks to develop a robust model of how people’s thoughts, ideas, and cognitive practices influence their health and well-being. She is drawing on research from cognitive neuroscience, as well as anthropology, to inform her work. The project has implications for the development of interventions to improve mental and physical health, highlighting the importance of considering mind-body processes in affecting health outcomes. In December, Seligman participated in a conference on the power of the mind at Stanford University. Invited researchers explored how to apply knowledge about mind-body processes to address inequality.

Immigration and Mental Health
The United States is in the midst of a debate about whether or not to deport its estimated 11 million unauthorized immigrants, but the fact that these immigrants are parents to more than 4 million U.S.-born children is often overlooked. A research team including IPR associate
Bernard Black, the Nicholas J. Chabraja Professor of Law, examines the impact of parents’ immigration status on the mental health of their children in Science. Black and his colleagues use Medicaid claims data from Oregon and the effectively random assignment of eligibility for the Deferred Action for Childhood Arrivals (DACA) program, which provides partial legalization, among mothers with birth dates either shortly before or shortly after the June 30, 1981 birth date cutoff in the DACA executive order. They find that children of DACA-eligible mothers had fewer adjustment and anxiety disorder diagnoses. The researchers conclude that parents’ unauthorized status is a substantial risk factor for mental health issues.

Brain Activity and Mental Health
Depression and anxiety are often diagnosed together. Evidence suggests that individuals with depression display reduced activity in the brain’s left prefrontal cortex. Do patients with both depression and anxiety also have lower resting-state prefrontal EEG activity? Psychologist and IPR associate Robin Nusslock tests women with a history of childhood-onset depressive disorder who either had a current anxiety diagnosis or no current diagnosis, as well as controls with no mental health problems. In Psychophysiology, he shows that depressed women without an anxiety diagnosis had significantly lower levels of left prefrontal activity compared with healthy controls and women who had both depression and anxiety. The findings indicate that decreased left frontal activity might be specific to a variant of depression that does not co-occur with anxiety disorders, and that comorbid anxiety suppresses or masks the relationship between depression and prefrontal asymmetry.

Pinpointing the Risk for Psychosis
Psychologist and IPR associate Vijay Mittal is working to identify signs of psychosis prior to its onset. In Schizophrenia Research, Mittal uses motion energy analysis to test differences between youth at high risk for psychosis and their healthy peers. The video analysis software provides frame-by-frame measures for both head and body movement in terms of total movement, amplitude, speed, and variability. He discovers significant differences in body movement between the groups, with youth at high risk for psychosis showing greater total body movement as well as faster body movements. The high-risk youth also had less variation in body movement compared with participants not at risk. Mittal concludes that motion energy analysis could be a helpful tool in assessing psychosis risk.  

Identifying the Genetic Roots of Autism
Autism affects an estimated 1 in 68 children in the United States. Communication studies researcher and IPR associate Molly Losh is investigating the genetic roots of autism to try to identify autism spectrum disorder (ASD) earlier and understand how it is transmitted in families. In the Journal of Autism and Developmental Disorders, Losh examines the school test scores of parents of children with ASD. She finds that parents of children with ASD are more likely to show a split between their language and math skills, with one being significantly better than the other. The severity of this discrepancy even predicted the severity of autism in their children. Losh is also extending this work with economists Figlio and Joseph Ferrie, an IPR associate, to detect a similar split in children. Their results show that those who were good at recognizing letters but struggled with recognizing sounds were 2.5 times more likely to be diagnosed with autism than children who did not show this difference. Losh holds the JoAnn and Peter Dolle Chair in Learning Disabilities.

Sera Young
IPR anthropologist Sera Young leads a
brainstorming session at a workshop
she organized for researchers working to
create a cross-culturally validated scale
of water insecurity at the household level.

Measuring Water Insecurity
With an international team of researchers, IPR anthropologist Sera Young is working to develop the first cross-culturally validated scale of water insecurity for households. The scale, which will resemble those already used for food insecurity, will help scientists understand the prevalence and severity of water insecurity in a community and to better study its health impacts. It will also enable measurement of interventions’ effectiveness over time and provide better targeting of resources to the most vulnerable populations. The scale’s questions cover various aspects of water use, including how frequently anyone in a household has had to drink unsafe water or gone to sleep thirsty in the last month. With funding from several Northwestern institutes and programs, including IPR, Young hosted an international workshop to discuss how to improve ongoing data collection. At the workshop, researchers from 17 universities and six countries also worked to reduce the number of questions on the scale. The researchers are validating the scale in 29 study sites, including India, Samoa, Guatemala, and Ghana, and have completed data collection for more than 3,800 participants. They have received funding from Innovative Methods and Metrics for Agriculture and Nutrition, a research initiative supported by the U.K. Department for International Development.

Food and Water Insecurity in Kenya
In a NIH-funded study in Kenya, Young explored the consequences of food and water insecurity for mothers and their infants. Young and her colleagues enrolled 371 pregnant and lactating women in the Pith Moromo study, some of whom were infected with HIV. The researchers find that food insecurity had a negative effect on child development. Children born to mothers with moderate or severe food insecurity developed more slowly and had lower development scores than children born to mothers with less food insecurity. In related work in Kenya, Young is using her household-level water insecurity scale to assess a range of outcomes linked to water insecurity, including viral load, maternal depression, stress, food insecurity, and cognitive development. Preliminary results show that water insecurity leads to stress and maternal depression, which in turn can lead to poor infant bonding. The research also highlights how water insecurity is tied to food insecurity, with one study participant noting that she can afford to buy either water or food—but not both.

Educating Farmers to Address Stunting
Approximately 40 percent of children under age 5 are stunted in Tanzania. Previous research identified issues faced by small farmers that might contribute to this rate of stunting, including poor farmer education. The Singida Nutrition and Agroecology Project is trying to address this through a peer farmer education intervention, which will address agroecology, climate change, nutrition, and gender equality. Young is investigating whether the program increases farmers’ knowledge of nutrition, particularly of infant and child feeding practices, and promotes women’s empowerment. She also plans to draw on her water insecurity research to explore how water affects agriculture production and the ways in which it mediates gender dynamics within the household.

Preserving and Restoring Fertility
Oncofertility specialist and IPR associate
Teresa Woodruff is making great gains to help preserve women’s fertility—and even restore the fertility of women affected by cancer. Woodruff and her team at the Women’s Health Research Institute recently developed a miniature female reproductive tract, described in Nature Communications. The new 3D technology—called EVATAR—is made with human tissue. It will enable scientists to test new drugs for safety and effectiveness on the female reproductive system instead of using human subjects. It will also help researchers understand diseases of the female reproductive tract, including endometriosis, cancer, and infertility. In another scientific first, Woodruff has developed a functional biosynthetic ovary. After removing a female mouse’s ovary and replacing it with a bioprosthetic ovary, constructed of 3D printed scaffolds that house immature eggs, the mouse was able to not only ovulate but also give birth to healthy pups. The mothers were even able to nurse their young. Woodruff and her colleagues’ objective for developing the bioprosthetic ovaries is to help restore fertility and hormone production in women who have undergone adult cancer treatments or those who survived childhood cancer and now have increased risks of infertility and hormone-based developmental issues. Woodruff is the Thomas J. Watkins Professor of Obstetrics and Gynecology.