Impact of Racial Discrimination and Hostility on Adrenergic Receptor Responsiveness in African American Adults

Racial/Ethnic Discrimination and Cardiometabolic Diseases: A Systematic Review

INTRODUCTION

Racial discrimination has been identified as a risk factor for cardiometabolic diseases, the leading cause of morbidity and mortality among racial/ethnic minority groups; however, there is no synthesis of current knowledge on the association between discrimination and cardiometabolic diseases. The objective of this systematic review was to summarize evidence linking racial/ethnic discrimination and cardiometabolic diseases.

METHODS

The review was conducted based on studies identified via electronic searches of 5 databases (PubMed, Google Scholar, WorldWideScience.org, ResearchGate and Microsoft Academic) using terms related to discrimination and cardiometabolic disease.

RESULTS

Of the 123 eligible studies included in the review, 87 were cross-sectional, 25 longitudinal, 8 quasi-experimental, 2 randomized controlled trials and 1 case-control. Cardiometabolic disease outcomes discussed were hypertension (n = 46), cardiovascular disease (n = 40), obesity (n = 12), diabetes (n = 11), metabolic syndrome (n = 9), and chronic kidney disease (n = 5). Although a variety of discrimination measures was employed across the studies, the Everyday Discrimination Scale was used most often (32.5%). African Americans/Blacks were the most frequently studied racial/ethnic group (53.1%), and American Indians the least (0.02%). Significant associations between racial/ethnic discrimination and cardiometabolic disease were found in 73.2% of the studies.

DISCUSSION

Racial/ethnic discrimination is positively associated with increased risk of cardiometabolic disease and higher levels of cardiometabolic biomarkers. Identifying racial/ethnic discrimination as a potential key contributor to the health inequities associated with cardiometabolic diseases is important for addressing the significant burden borne by racial/ethnic minorities.

Psychosocial stress and neuroendocrine biomarker concentrations among women living with or without HIV

OBJECTIVE

Women living with HIV (WLWH) experience psychosocial stress related to social-structural vulnerabilities. To investigate neuroendocrine pathways linking stress and increased cardiovascular disease risk among WLWH, we evaluated associations between psychosocial stress (i.e., perceived stress, posttraumatic stress, and experiences of race- and gender-based harassment) and a composite neuroendocrine biomarker index among WLWH and women without HIV.

METHODS

In 2019-2020, Women's Interagency HIV Study participants in Washington, DC completed a questionnaire and provided blood and 12-hour overnight urine samples for testing of serum dehydroepiandrosterone sulfate (DHEA-S) and urinary free cortisol, epinephrine, and norepinephrine. Psychosocial stress was measured using the Perceived Stress Scale, PTSD Checklist-Civilian Version, and Racialized Sexual Harassment Scale. Latent profile analysis was used to classify participants into low (38%), moderate (44%), and high (18%) stress groups. Composite biomarker index scores between 0-4 were assigned based on participants' number of neuroendocrine biomarkers in high-risk quartiles (≥75th percentile for cortisol, epinephrine, and norepinephrine and ≤25th percentile for DHEA-S). We evaluated associations between latent profile and composite biomarker index values using multivariable linear regression, adjusting for socio-demographic, behavioral, metabolic, and HIV-related factors.

RESULTS

Among 90 women, 62% were WLWH, 53% were non-Hispanic Black, and median age was 55 years. In full multivariable models, there was no statistically significant association between psychosocial stress and composite biomarker index values among all women independent of HIV status. High (vs. low) psychosocial stress was positively associated with higher mean composite biomarker index values among all monoracial Black women (adjusted β = 1.32; 95% CI: 0.20-2.43), Black WLWH (adjusted β = 1.93; 95% CI: 0.02-3.83) and Black HIV-negative women (adjusted β = 2.54; 95% CI: 0.41-4.67).

CONCLUSIONS

Despite a null association in the overall sample, greater psychosocial stress was positively associated with higher neuroendocrine biomarker concentrations among Black women, highlighting a plausible mechanism by which psychosocial stress could contribute to cardiovascular disease risk.

Ethnic Differences in Resting Total Peripheral Resistance: A Systematic Review and Meta-Analysis

OBJECTIVE

Decades of research suggest that there may be important ethnic differences in the hemodynamic mechanisms that co-determine arterial blood pressure, the primary diagnostic index of hypertension. In general, studies have observed that, compared with European Americans (EAs), African Americans (AAs) exhibit higher total peripheral resistance (TPR), an important summative index of peripheral vascular constriction. In contrast, EAs have been reliably shown to exhibit greater cardiac output (CO), which is directly linked to left ventricle and overall cardiac blood flow. We have previously proposed that elevated basal TPR, in particular, represents one component of the cardiovascular conundrum, characterized, paradoxically, by elevated resting heart rate variability among AAs relative to EAs. The present meta-analysis and systematic review of the literature sought to extend this previous work by establishing the magnitude of the empirically implied ethnic differences in resting TPR and CO.

METHODS

A search of the literature yielded 140 abstracts on differences in TPR between AAs and EAs; 40 were included. Sample sizes, means, and standard deviations for baseline TPR with samples that included EAs and AAs were collected, and Hedges g was computed.

RESULTS

Findings indicated that AAs had higher baseline TPR than did EAs (Hedges g = 0.307, SE = 0.043, confidence interval= 0.224 to 0.391, p < .001). In addition, EAs had higher resting CO than did AAs (Hedges g = -0.214, SE = 0.056, confidence interval = -0.324 to -0.104, p < .001).

CONCLUSIONS

We discuss the present findings in the context of the role of elevated TPR in the deleterious effects of high blood pressure specifically for AAs.

Twitter-Characterized Sentiment Towards Racial/Ethnic Minorities and Cardiovascular Disease (CVD) Outcomes

Sentiments towards racial/ethnic minorities may impact cardiovascular disease (CVD) through direct and indirect pathways. In this study, we assessed the association between Twitter-derived sentiments towards racial/ethnic minorities at state-level and individual-level CVD-related outcomes from the 2017 Behavioral Risk Factor Surveillance System (BRFSS). Outcomes included hypertension, diabetes, obesity, stroke, myocardial infarction (MI), coronary heart disease (CHD), and any CVD from BRFSS 2017 (N = 433,434 to 433,680 across outcomes). A total of 30 million race-related tweets were collected using Twitter Streaming Application Programming Interface (API) from 2015 to 2018. Prevalence of negative and positive sentiment towards racial/ethnic minorities were constructed at the state level and merged with CVD outcomes. Poisson regression was used, and all the models adjusted for individual-level demographics as well as state-level demographics. Individuals living in states with the highest level of negative sentiment towards racial/ethnic minorities had 11% higher prevalence of hypertension (PR 1.11, 95% CI 1.08, 1.14), 15% higher prevalence of diabetes (PR 1.15, 95% CI 1.08, 1.22), 14% higher prevalence of obesity (PR 1.14, 95% CI 1.10, 1.18), 30% higher prevalence of stroke (PR 1.30, 95% CI 1.16, 1.46), 14% higher prevalence of MI (PR 1.14, 95% CI 1.03, 1.25), 9% higher prevalence of CHD (PR 1.09, 95% CI 1.00, 1.19), and 16% higher prevalence of any CVD outcomes (PR 1.16, 95% CI 1.09, 1.24). Conversely, Twitter-derived positive sentiment towards racial/ethnic minorities was associated with a lower prevalence of CVD outcomes. Programs and policies that promote racially inclusive environments may improve population health.

Vascular α1-Adrenergic Receptor Responsiveness in Masked Hypertension

BACKGROUND

Masked hypertension (nonhypertensive in the clinic setting but hypertensive outside the clinic during wakefulness) is characterized by increased blood pressure in response to physical and emotional stressors that activate the sympathetic nervous system (SNS). However, no studies have assessed vascular reactivity to a pharmacological SNS challenge in individuals with masked hypertension.

METHODS

We analyzed data from 161 adults aged 25 to 45 years (mean ± standard deviation age 33 ± 6 years; 48% were African American and 43% were female). Participants completed ambulatory blood pressure monitoring, and a standardized α 1-adrenergic agonist phenylephrine test that determines the dose of phenylephrine required to increase a participant's mean arterial pressure by 25 mm Hg (PD25).

RESULTS

Twenty-one participants were considered to have masked hypertension (clinic systolic blood pressure (SBP) <140 and diastolic blood pressure (DBP) <90 mm Hg but awake SBP ≥135 or DBP ≥85 mm Hg), 28 had sustained hypertension (clinic SBP ≥140 or DBP ≥90 mm Hg and awake SBP ≥135 or DBP ≥85 mm Hg), and 106 had sustained normotension (clinic SBP <140 and DBP <90 mm Hg and awake SBP <135 and DBP <85 mm Hg). After multivariable adjustment, the mean (±SE) PD25 was less in participants with masked hypertension compared with their counterparts with sustained normotension (222.1 ± 33.2 vs. 328.7 ± 15.0; P = 0.012), but similar to that observed in subjects with sustained hypertension (254.8 ± 31.0; P =0.12).

CONCLUSIONS

Among young and middle-aged adults, masked hypertension is associated with increased vascular reactivity to a SNS challenge, which may contribute to elevated awake BPs as well as to increased cardiovascular disease risk.

Pervasive Discrimination and Allostatic Load in African American and White Adults

OBJECTIVE

This study aimed to examine associations among race, the accumulation of multiple forms of discriminatory experiences (i.e., "pervasive discrimination"), and allostatic load (AL) in African Americans and whites in midlife.

METHODS

Using data collected in 2004 to 2006 from 226 African American and 978 white adults (57% female; mean [SD] age = 54.7 [0.11] years) in the Midlife in the United States II Biomarker Project, a pervasive discrimination score was created by combining three discrimination scales, and an AL score was created based on 24 biomarkers representing seven physiological systems. Linear regression models were conducted to examine the association between pervasive discrimination and AL, adjusting for demographics and medical, behavioral, and personality covariates. A race by pervasive discrimination interaction was also examined to determine whether associations varied by race.

RESULTS

African Americans had higher pervasive discrimination and AL scores than did whites. In models adjusted for demographics, socioeconomic status, medications, health behaviors, neuroticism, and negative affect, a pervasive discrimination score of 2 versus 0 was associated with a greater AL score (b = 0.30, SE = 0.07, p < .001). Although associations seemed to be stronger among African Americans as compared with whites, associations did not statistically differ by race.

CONCLUSIONS

More pervasive discrimination was related to greater multisystemic physiological dysregulation in a cohort of African American and white adults. Measuring discrimination by combining multiple forms of discriminatory experiences may be important for studying the health effects of discrimination.

Interactive Relations Across Dimensions of Interpersonal-Level Discrimination and Depressive Symptoms to Carotid Intimal-Medial Thickening in African Americans

OBJECTIVE

This study aimed to examine within-race interactions of multiple dimensions of self-reported discrimination with depressive symptoms in relation to carotid intimal-medial thickness (IMT), a subclinical marker of atherosclerosis prospectively implicated in stroke incidence, in middle-aged to older African American and white adults.

METHODS

Participants were a socioeconomically diverse group of 1941 African Americans (56.5%) and whites from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (30-64 years old, 47% men, 45.2% with household income <125% federal poverty threshold) who underwent carotid IMT measurement. Discrimination was assessed across four dimensions (everyday, frequency across various social statuses, racial, and lifetime burden). The Center for Epidemiologic Studies Depression scale was used to assess depressive symptoms.

RESULTS

In cross-sectional hierarchical regression analyses, two interactions were observed in African Americans: more frequent discrimination across various social statuses (b < 0.001, p = .006) and a higher lifetime discrimination burden (b < 0.001, p = .02) were each related to thicker carotid IMT in those with greater depressive symptoms. No significant findings were observed within whites.

CONCLUSIONS

Among African Americans, those reporting high levels of discrimination and depressive symptoms have increased carotid atherosclerosis and may be at greater risk for clinical end points compared with those reporting one or neither of these risk factors. Findings suggest that assessment of interactive relationships among social and psychological factors may elucidate novel pathways for cardiovascular disease, including stroke, among African Americans.

Sex Differences in the Impact of Racial Discrimination on Mental Health Among Black Americans

PURPOSE OF REVIEW

Greater racial discrimination is associated with poorer mental health among Black Americans; yet, there remains an incomplete understanding of sex differences in exposure to racial discrimination, and further, of how sex differences in coping with racial discrimination may heighten or diminish risk for poorer mental health.

RECENT FINDINGS

Black men may experience greater exposure to both structural and communal forms of racial discrimination, whereas Black women may face both a wider range of potential sources, as well as encounter greater variability in the subjective experience of racial discrimination. For both Black women and men, racial discrimination may be similarly associated with maladaptive coping strategies (i.e., emotional eating, rumination) that also are linked to poorer mental health; however, emerging findings suggest that mindfulness may partially buffer these deleterious effects. Overall, the recent literature reveals mixed findings with respect to sex differences in the experience and negative mental health impact of racial discrimination. Despite this heterogeneity, evidence documents sex differences in the settings, type, and qualitative experience of racial discrimination among Black Americans. Additionally, growing evidence indicating that racial discrimination is associated with physiological markers of stress reactivity and psychopathology risk further bolsters its characterization as a unique form of chronic stress among Black Americans and other minority groups in the USA.

The Autonomic Nervous System and Hypertension: Ethnic Differences and Psychosocial Factors

PURPOSE OF THE REVIEW

In the present paper, we overview emerging research examining the autonomic nervous system (ANS), especially the parasympathetic nervous system as indexed by heart rate variability (HRV), and the impact of psychosocial factors on hypertension-related disease in African Americans.

RECENT FINDINGS

A growing corpus of studies has shown that (1) usual patterns of compensatory sympathetic-parasympathetic regulation differ between African Americans and European Americans; (2) despite their enhanced cardiovascular disease risk profile, African Americans tend to exhibit higher HRV relative to European Americans; and (3) racial discrimination and other forms of psychosocial stress are associated with diminished HRV among African Americans. Significant disparities in hypertension-related disease exist such that African Americans have greater risk. The underlying factors associated with this increased risk are, to date, not fully understood. The present review provides evidence for a unique pattern of ANS regulation in African Americans and shows that psychosocial factors such as racial discrimination may contribute to this paradoxical situation.

Active coping moderates associations among race-related stress, rumination, and depressive symptoms in emerging adult African American women

Cross-sectional and longitudinal research has shown that race-related stress is associated with increased depressive symptoms among racial/ethnic minorities. Rumination has long been considered a maladaptive self-regulatory response to race-related stress, and growing evidence suggests that it may be an important link in the relation between race-related stress and depression. More adaptive forms of self-regulation, such as active coping, may counteract the negative impact of rumination. We examined the influence of rumination on the relation between race-related stress and depressive symptoms in a sample (N = 69) of young adult (mean age = 20 ± 1.5 years) African American women. We also considered the possible moderating effects of John Henryism, a form of persistent and determined goal striving, and vagally mediated heart rate variability, a purported biomarker of coping. Anticipatory race-related stress was indirectly associated with depressive symptoms through rumination: estimate = 0.07, 95% confidence interval [0.01, 0.16]. Both John Henryism and vagally mediated heart rate variability moderated the relationship between race-related stress and rumination; however, only John Henryism reliably influenced the indirect association between race-related stress and depression through rumination. We discuss these findings in the context of growing research examining the interplay between cultural and biological factors in the risk for poorer mental health.