Racial discrimination and leukocyte glucocorticoid sensitivity: Implications for birth timing

Structural Violence and Stress Experiences of Young Pregnant Black People

INTRODUCTION

Approximately 10-20% of individuals suffer from mental health concerns during the prenatal period due to their vulnerability and emotional responses to stressful events. Mental health disorders are more likely to be disabling and persistent for people of color, and they are less likely to seek treatment due to stigma. Young pregnant Black people report experiencing stress due to isolation, feelings of conflict, lack of material and emotional resources, and support from significant others. Although many studies have reported the types of stressors experienced, personal resources, emotional stress responses on pregnancy, and mental health outcomes, there is limited data on young Black women's perceptions of these factors.

METHODS

This study utilizes the Health Disparities Research Framework to conceptualize drivers of stress related to maternal health outcomes for young Black women. We conducted a thematic analysis to identify stressors for young Black women.

RESULTS

Findings revealed the following overarching themes: Societal stress of being young, Black, and pregnant; Community level systems that perpetuate stress and structural violence; Interpersonal level stressors; Individual level effects of stress on mom and baby; and Coping with stress.

DISCUSSION

Acknowledging and naming structural violence and addressing structures that create and fuel stress for young pregnant Black people are important first steps to interrogating systems that allow for nuanced power dynamics and for recognizing the full humanity of young pregnant Black people.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

Neighborhood racial composition and experiences of racial discrimination: Associations with cytokines during pregnancy among African American women

Background

Preterm birth rates are consistently higher in African American (AA) pregnancies compared to White pregnancies in the United States. Neighborhood racial composition, experiences of racial discrimination, and systemic inflammation are factors that have been associated with preterm birth and other adverse pregnancy outcomes that may account for these disparities. Here, we investigated whether perceived neighborhood racial composition and experiences of discrimination were predictive of cytokine levels during pregnancy among AA individuals.

Methods

545 AA individuals completed surveys and had blood samples collected at prenatal clinics in the Midwest at three timepoints (8-18,19-29, and 30-36 weeks gestation) throughout pregnancy. Pro-inflammatory [interferon (IFN)-γ, interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, macrophage migration inhibitory factor (MIF)] and anti-inflammatory cytokines (IL-10) were quantified. Multivariate and multilevel models were used to examine associations of perceived neighborhood racial composition and experiences of racial discrimination with cytokine levels, controlling for relevant covariates.

Results

Perceived neighborhood racial composition was significantly associated with MIF at 30-36 weeks gestation in multivariate regression (p < 0.001). Living in neighborhoods with more compared to fewer White people was predictive of higher levels of MIF (b = 0.599, SE = 0.12, p < 0.001). Experiences of discrimination were also associated with higher levels of MIF (β = 0.141, SE = 0.07, p = 0.036). Neither predictor was associated with other cytokines. Follow-up analyses revealed that neighborhood racial composition was also predictive of higher MIF levels at 8-18 weeks gestation (p = 0.02) and at 19-29 weeks gestation (p = 0.04).

Conclusions

Living in neighborhoods with more White individuals and having more lifetime experiences of racial discrimination were positively related to levels of the pro-inflammatory cytokine, MIF, among pregnant AA individuals. MIF's known positive relationships with chronic stress and preterm birth suggest that these elevations in MIF may have negative health consequences. Future studies should explore whether MIF serves as a pathway between neighborhood racial composition or experiences of racial discrimination and preterm birth risk among AA individuals.

Depression, anxiety, and stress in pregnant Black people: A case for screening and evidence-based intervention

BACKGROUND

Guidelines call for pregnant people to be screened for depression and anxiety. Screening may be particularly important for pregnant Black individuals who are reported to be more likely than non-Hispanic White pregnant people to experience prenatal stress, anxiety, and depressive symptoms. The purpose of this study was to determine if depression, anxiety, and stress co-occur in pregnant Black people and to identify which demographic factors are related to these mental health concerns.

METHODS

A subset analysis of an ongoing randomized controlled trial examined the risk of coexisting mental health conditions in pregnant Black people who screened eligible to participate (that is, they had high levels of depression, anxiety, and/or stress) in two urban clinics using a descriptive correlational design.

RESULTS

Of the 452 pregnant Black people who were screened for eligibility, 194 (42.9%) had elevated scores on depression, anxiety, and/or stress measures and were enrolled in the larger study. The average scores of the 194 enrolled participants were anxiety, mean (M) = 9.16 (standard deviation [SD] = 4.30); depression, M = 12.80 (SD = 4.27); and stress, M = 21.79 (SD = 4.76). More than one-third (n = 70, 36.1%) experienced two symptoms and 64 (33.0%) reported all three symptoms.

CONCLUSION

Pregnant Black individuals experience high levels of comorbid mental health distress including depression, anxiety, and stress. The findings indicate that treatment for mental health concerns needs to be broad-based and effective for all three conditions. Prenatal interventions should aim to address mental health distress through screening and treatment of depression, anxiety, and stress, especially for pregnant Black individuals. This study furthers understanding of the prevalence of prenatal mental health conditions in pregnant Black people.

Associations Between Latent Classes of Trauma Exposure and Minority Stressors and Substance Use Among Cisgender Sexual Minority Women

Psychosocial stressors (e.g., minority stressors, trauma exposure) profoundly impact sexual minority women's (SMW's) risk of alcohol and other drug (AOD) use. However, research has not examined whether there are distinct typologies (i.e., patterns) of psychosocial stressors and whether these vary based on sociodemographic characteristics or are differentially associated with AOD outcomes (e.g., alcohol dependence) among SMW. This study aimed to identify latent classes of SMW reporting distinct typologies of psychosocial stressors and examine predictors and outcomes of latent classes of psychosocial stressors among SMW. Participants included a community sample of 602 SMW (Mage = 39.9, SD = 14.0; 74.0% lesbian; 37.4% White, 36.6% Black, 22.3% Latinx; 26.6% annual income ≤$14,999). Latent class analysis was used to identify typologies of psychosocial stressors. Regression analyses were employed to examine sociodemographic predictors and AOD outcomes of class membership. Three classes of psychosocial stressors emerged. Participants in Class 1 were likely to report relatively low adversity. SMW in Class 2, who reported childhood physical abuse (CPA), severe childhood sexual abuse, and adult physical assault, were vulnerable to discrimination and stigma consciousness. A distinct subgroup of SMW (Class 3) was at heightened risk of CPA, adult sexual assault (ASA), and stigma consciousness. Older SMW, Black SMW, and SMW with lower social support were more likely to be in classes characterized by higher adversity. Older SMW were at disproportionate risk of CPA and ASA. Different combinations of psychosocial stressors were uniquely associated with AOD outcomes. Findings underscore the importance of considering within-group heterogeneity in SMW's differential risk of psychosocial stressors and AOD outcomes. Routine screening of psychosocial stressors across several dimensions, brief interventions targeting AOD outcomes, and policies mitigating structural drivers of SMW's increased risk of trauma and minority stressors may be especially important for older SMW, Black SMW, and SMW who lack social support.

By what molecular mechanisms do social determinants impact cardiometabolic risk?

While it is well known from numerous epidemiologic investigations that social determinants (socioeconomic, environmental, and psychosocial factors exposed to over the life-course) can dramatically impact cardiovascular health, the molecular mechanisms by which social determinants lead to poor cardiometabolic outcomes are not well understood. This review comprehensively summarizes a variety of current topics surrounding the biological effects of adverse social determinants (i.e., the biology of adversity), linking translational and laboratory studies with epidemiologic findings. With a strong focus on the biological effects of chronic stress, we highlight an array of studies on molecular and immunological signaling in the context of social determinants of health (SDoH). The main topics covered include biomarkers of sympathetic nervous system and hypothalamic-pituitary-adrenal axis activation, and the role of inflammation in the biology of adversity focusing on glucocorticoid resistance and key inflammatory cytokines linked to psychosocial and environmental stressors (PSES). We then further discuss the effect of SDoH on immune cell distribution and characterization by subset, receptor expression, and function. Lastly, we describe epigenetic regulation of the chronic stress response and effects of SDoH on telomere length and aging. Ultimately, we highlight critical knowledge gaps for future research as we strive to develop more targeted interventions that account for SDoH to improve cardiometabolic health for at-risk, vulnerable populations.

Social Determinants of Cardiovascular Disease

Social determinants of health (SDoH), which encompass the economic, social, environmental, and psychosocial factors that influence health, play a significant role in the development of cardiovascular disease (CVD) risk factors as well as CVD morbidity and mortality. The COVID-19 pandemic and the current social justice movement sparked by the death of George Floyd have laid bare long-existing health inequities in our society driven by SDoH. Despite a recent focus on these structural drivers of health disparities, the impact of SDoH on cardiovascular health and CVD outcomes remains understudied and incompletely understood. To further investigate the mechanisms connecting SDoH and CVD, and ultimately design targeted and effective interventions, it is important to foster interdisciplinary efforts that incorporate translational, epidemiological, and clinical research in examining SDoH-CVD relationships. This review aims to facilitate research coordination and intervention development by providing an evidence-based framework for SDoH rooted in the lived experiences of marginalized populations. Our framework highlights critical structural/socioeconomic, environmental, and psychosocial factors most strongly associated with CVD and explores several of the underlying biologic mechanisms connecting SDoH to CVD pathogenesis, including excess stress hormones, inflammation, immune cell function, and cellular aging. We present landmark studies and recent findings about SDoH in our framework, with careful consideration of the constructs and measures utilized. Finally, we provide a roadmap for future SDoH research focused on individual, clinical, and policy approaches directed towards developing multilevel community-engaged interventions to promote cardiovascular health.

A Comparison of Recruitment Methods for a Prospective Cohort Study of Perinatal Psychoneuroimmunology among Black American Women

Improved understanding of perinatal psychoneuroimmunology is needed, particularly to combat the high rates of maternal and infant mortality witnessed among Black Americans. We compared the success of recruitment by advertisement, in person, or by phone during the course of a prospective cohort study of perinatal psychoneuroimmunology among Black American women. Over 24 months, 363 women were assessed and 96 were enrolled. Women recruited by phone were less likely to complete full screening than women recruited by advertisement (OR = 0.32, p < 0.01) or in person (OR = 0.19, p < 0.01). Women recruited by advertisement were less likely to complete full screening than women recruited in person (OR = 0.60, p = 0.05). Odds of unsuccessful contact were 13.2 and 11.5 times greater among women recruited by phone versus by advertisement or in person, respectively (p values ≤ 0.01). Women recruited by advertisement and in person showed similar odds of unsuccessful contact (OR = 0.87, p = 0.76). Odds of screening decline were similar following recruitment in person or by phone when contact was successful (OR = 0.85, p = 0.76). Focusing on eligible women (n = 142), those recruited in person were significantly less likely to enroll than those recruited by advertisement (OR = 0.28, p < 0.01; Fig. 4). Considering all women (n = 363), odds of enrollment did not significantly differ among the recruitment groups (p values ≥ 0.09). Most (93.8%) enrolled women consented to biological specimen banking. Findings from this brief report provide a starting point for perinatal scientists to critically consider not only how to maximize research efforts but also how research team actions may perpetuate or assuage the research mistrust introduced by long-standing social inequities.

Racial differences across pregnancy in maternal pro-inflammatory immune responsivity and its regulation by glucocorticoids

BACKGROUND

The distribution of adverse pregnancy, birth and subsequent child developmental and health outcomes in the U.S. is characterized by pronounced racial (particularly Black-white) disparities. In this context, chronic stress exposure represents a variable of considerable importance, and the immune/inflammatory system represents a leading candidate biological pathway of interest. Previous pregnancy studies examining racial disparities in immune processes have largely utilized circulating cytokine levels, and have yielded null or mixed results. Circulating cytokines primarily represent basal secretion and do not necessarily represent functional features of immune responsivity and regulation. Thus, in order to conduct a more in-depth characterization of racial differences in functional immune properties during pregnancy, we utilized an ex vivo stimulation assay, a dynamic measure of immune function at the cellular level, to investigate Black-white racial differences in in mid- and late-gestation in i) pro-inflammatory (IL-6) responsivity of leukocytes to antigen [lipopolysaccharide (LPS)] challenge, and ii) regulation (dampening) of this pro-inflammatory response by glucocorticoids.

METHOD

177 women (N = 42 Black (24%), n = 135 white (76%)) with a singleton, intrauterine pregnancy provided 20 mL venous blood in mid- (16.6 ± 2.4 wks) and late (33.3 ± 1.1 wks) pregnancy. Maternal pro-inflammatory responsivity of leukocytes was quantified by assessing the release of the pro-inflammatory cytokine IL-6 in response to LPS stimulation, and regulation of the pro-inflammatory response was quantified by assessing the suppression of the stimulated IL-6 response after co-incubation with progressively increasing levels of dexamethasone [10-7, 10-6, 10-5 M] (i.e., glucocorticoid receptor resistance (GRR)). A priori model covariates included maternal age, parity, SES (socioeconomic status), and pre-pregnancy BMI.

RESULTS

Maternal pro-inflammatory responsivity (LPS-stimulated IL-6) and GRR increased significantly across mid- and late gestation (adjusted β = 0.157, p = 0.007; β = 0.627, p < 0.001, respectively). Across both time points in pregnancy Black women exhibited significantly higher LPS-stimulated IL-6 release and reduced glucocorticoid regulation of the IL-6 response (i.e., higher GRR) relative to white women, before and after adjusting for covariates (β = 0.381, p = 0.0030; β = 0.391, p = 0.0075, respectively). There was no racial difference in the concentrations of circulating IL-6 (p = 0.9199).

CONCLUSION

Our findings support the hypothesis postulating significant racial (Black-white) differences in key functional properties of the maternal immune system in pregnancy, which were not apparent using circulating cytokine measures. These data elucidate a potentially important physiological mechanism underlying the transduction of environmental conditions into racial disparities in reproductive and subsequent child health outcomes, and the use of these ex vivo measures should be considered in future studies.

Racial Discrimination and Stress Across the Life Course: Associations With Prenatal Inflammation, Perceived Stress, and Depressive Symptoms

BACKGROUND

Among Black Americans, interpersonal racial discrimination is common. Stress, including following discrimination, contributes to pregnancy complications. In this secondary analysis, we provide data on associations among discrimination, stress, and their interaction across the life course and inflammation, perceived stress, and depressive symptoms during pregnancy.

METHODS

During the early third trimester, Black American women (n = 93) completed the Experiences of Discrimination Scale, the Stress and Adversity Inventory, the Perceived Stress Scale, and the Center for Epidemiological Studies Depression Inventory. Plasma interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), and IL-β levels were quantified. Associations were examined by linear regression, controlling for demographic, behavioral, and clinical covariates.

RESULTS

Associations among racial discrimination and plasma IL-8, TNF-α, and IL-β levels depended upon average ratings of life course stress. When stress was low, discrimination in the mid tertile was associated with the highest levels of IL-8, TNF-α, and IL-β. Subscale analyses suggested that findings related to IL-8 were driven by chronic stress whereas findings related to TNF-α and IL-β were driven by acute stress. When examined together, greater discrimination but not greater life course stress was associated with higher prenatal perceived stress. In subscale analyses, the association between discrimination and prenatal perceived stress depended upon average ratings of life course acute stress. When acute stress was low, discrimination in the midtertile was associated with the highest levels of prenatal perceived stress. When acute stress was high, discrimination in the high tertile was associated with the highest levels of prenatal perceived stress. There were also direct associations among greater life course chronic stress, prenatal perceived stress, and prenatal depressive symptoms. Associations were attenuated when discrimination was included as a covariate.

CONCLUSIONS

The current analyses suggest that, among Black Americans, prenatal inflammation, perceived stress, and depressive symptoms may be shaped by racial discrimination and stress across the life course. In many cases, associations among discrimination and prenatal parameters depended upon how stressful exposures to life course stressors had been rated. The data suggest the potential for adaptive plasticity under some stress and highlight the deleterious nature of compounding stress.

The Association between Maternal Experiences of Interpersonal Discrimination and Adverse Birth Outcomes: A Systematic Review of the Evidence

In the present systematic review, we argue that maternal experiences of interpersonal discrimination at least partially account for the disproportionate rates of adverse birth outcomes in minority populations. Since the 1990s, research in this area has slowly, but steadily increased, shedding more light on the insidious nature of interpersonal discrimination and its toxic health effects. With the aim of bringing this topic to the fore in academic as well as clinical settings, this paper provides a state-of-the-art review of the empirical knowledge on the relationship between maternal experiences of discrimination and birth outcomes. Of 5901 articles retained in the literature search, 28 met the predefined inclusion criteria. Accounting for a range of health and behavioral factors, the vast majority of these studies support the notion that maternal experiences of interpersonal discrimination predict a range of adverse birth outcomes, including preterm birth, low birth weight, and various physiological markers of stress (allostatic load) in both mother and child pre- and postpartum. Several moderators and mediators of this relationship were also identified. These related primarily to the type (first-hand and vicarious), timing (childhood, adolescence, and adulthood), frequency, and pervasiveness of discrimination experienced, as well as to maternal mental health and coping. More research into these factors, however, is required to definitively determine their significance. We discuss these findings as they relate to the general health repercussions of interpersonal discrimination, as well as in terms of applied prenatal care and interventions. Ultimately, we argue that assessing maternal experiences of interpersonal discrimination in prenatal care may represent a considerable asset for mitigating existing majority-minority disparities in adverse birth outcomes.

Glucocorticoid receptor sensitivity in early pregnancy in an African American cohort

PROBLEM

Disruption in homeostatic feedback loops between inflammatory mediators and the hypothalamic-pituitary-adrenal (HPA) axis is a key mechanism linking chronic stress to inflammation and adverse health outcomes, including those occurring during pregnancy. In particular, alterations in glucocorticoid sensitivity may occur as a result of chronic stress, including that due to racial discrimination, and may be implicated in the persistent adverse maternal and infant health outcomes experienced by African Americans. While there are a few large-scale studies in human pregnancy that measure both cytokines and HPA axis hormones, to our knowledge, none directly measure glucocorticoid sensitivity at the cellular level, especially in an African American population.

METHOD OF STUDY

We measured the full range of the dexamethasone (DEX) dose-response suppression of TNF-α in first-trimester blood samples from 408 African American women and estimated leukocyte cell type contribution to the production of TNF-α.

RESULTS

The mean (SD) DEX level needed to inhibit TNF-α production by 50% (ie, DEX IC50 ) was 9.8 (5.8) nmol/L. Monocytes appeared to be the main driver of Uninhibited TNF-α production, but monocyte counts explained only 14% of the variation. Monocyte counts were only weakly correlated with the DEX IC50 (r = -.11, P < .05). Moreover, there was no statistically significant correlation between the DEX IC50 and circulating pro-inflammatory (CRP, IL-6, IFN-γ) or anti-inflammatory (IL-10) mediators (P > .05).

CONCLUSION

These findings challenge some prior assumptions and position this comprehensive study of glucocorticoid sensitivity as an important anchor point in the growing recognition of interindividual variation in maternal HPA axis regulation and inflammatory responses.

Metabolites and metabolic pathways associated with glucocorticoid resistance in pregnant African-American women

Glucocorticoid resistance (GR) is associated with exposure to chronic stress and an increased risk of metabolic and inflammatory disorders in both animal and human populations. Studies on ethnic disparities highlight the African-American (AA) population as having a high propensity to both GR and chronic stress exposure. Glucocorticoids and inflammation play a very important role in pregnancy outcome and fetal development. To date, however, the metabolites and metabolic pathways associated with GR during pregnancy have not been identified, obscuring the mechanisms by which adverse health consequences arise, and thus impeding targeted therapeutic intervention. The objective of this study was to perform untargeted high-resolution metabolomics (HRM) profiling on 273 pregnant AA women, to identify metabolites and metabolic pathways associated with GR during the first trimester of pregnancy and to evaluate their cross-sectional association with birth outcomes and psychosocial variables related to chronic stress exposure. For this study, GR was determined by the concentration of dexamethasone required for 50% inhibition (Dex IC50) of the cytokine tumor-necrosis factor alpha (TNF-alpha) release in vitro in response to a standard dose of lipopolysaccharide. The results for Metabolome-Wide Association Studies (MWAS) and pathway enrichment analysis for serum metabolic associations with Dex IC50, showed energy (nicotinamide and TCA cycle), amino acid, and glycosphingolipid metabolism as top altered pathways. Bioinformatic analysis showed that GR, as indicated by elevated Dex IC50 in the pregnant women, was associated with increased inflammatory metabolites, oxidative stress related metabolites, increased demand for functional amino acids to support growth and development, and disruption in energy-related metabolites. If confirmed in future studies, targeting these physiologically significant metabolites and metabolic pathways may lead to future assessment and intervention strategies to prevent inflammatory and metabolic complications observed in pregnant populations.

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GR is associated with chronic stress and is a risk factor for adverse health outcomes, especially among African Americans.

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Metabolites and metabolic pathways associated with GR relate to energy production, amino acid metabolism, and inflammation.

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Findings provide a foundation for future studies investigating risk factors in this health disparity population.