Associations between everyday discrimination and sleep quality and duration among African-Americans over time in the Jackson Heart Study

Skin tone - a marker of bias known as colorism - in relation to sleep health among African American women

People with darker-skin tone are more likely than their lighter-skin counterparts to have less access to health-promoting resources (e.g., economic security; quality housing; favorable neighborhood environment). These adverse conditions can affect sleep and result in poor health outcomes such as cardiovascular disease and depression. However, few studies have examined associations between skin tone and sleep disparities. To address this gap, we used cross-sectional (2010-2012) and longitudinal (until 2014-2018) data from the Study of Environment, Lifestyle and Fibroids cohort of 1674 Black women aged 23-35 years and residing in the Detroit, Michigan area. Skin tone was measured using a skin reflectance instrument and categorized as light [29.3-57.6] (25%), medium [57.7-72.4] (50%), and dark [72.5-106.1] (25%) brown. Self-reported sleep dimensions were dichotomized (yes vs. no): short sleep duration, non-restorative sleep, insomnia symptoms, and sleep apnea. Adjusting for age and educational attainment, we used Poisson regression with robust variance to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) and applied generalized estimating equations to log binomial models to determine risk ratios (RRs) and 95% CIs between skin tone and each sleep dimension, separately. Dark vs. light skin tone was associated with marginally higher prevalence and risk of short sleep (PR = 1.04 [95% CI:1.00-1.08]; RR = 1.07 [95% CI: 0.99-1.16]) and a lower prevalence of insomnia symptoms (PR = 0.95 [95% CI: 0.91-0.99]). Insomnia symptoms were more prevalent among women with light skin tone (21.1% vs. 17.7% [medium] and 15.6% [dark]). Our findings elucidate the critical importance and need to address the differential impact of historical ideologies, systems, policies, and practices on Black women, which can manifest health-damaging social phenomena like colorism.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Socioeconomic status and sleep duration among a representative, cross-sectional sample of US adults

BACKGROUND

Sleep is a crucial determinant of physical and mental health outcomes, and insufficient sleep is highly prevalent among United States adults. Although some risk factors of poor sleep have been extensively studied, including substance use, age, health behaviors, and others, the associations between socioeconomic status (SES) and sleep remain inconclusive. There is limited evidence on SES and sleep duration among the US adult population. This study analyzed the relationships between three SES indicators (poverty, education, and food security), and sleep duration.

METHODS

We used responses from the 2017-March 2020 National Health and Nutrition Examination Survey (NHANES). Respondents younger than 25 years old were excluded. Sleep duration was classified using self-reported sleep time and stratified by work vs. non-workdays. SES was operationalized using three indicators: poverty-income ratio, educational attainment, and food security status. We imputed missing data for socioeconomic status and outcome variables using multiple imputation. Weighted Poisson regression models with robust standard errors were used to calculate the crude and adjusted prevalence ratios for insufficient sleep duration (< 7 h of self-reported sleep) on workdays and non-workdays separately by each of the three SES indicators.

RESULTS

We included a total of 8,457 individuals. In the adjusted model, participants with lower income, educational status, and food security had significantly higher prevalence of insufficient sleep duration on both workdays and non-workdays. For example, low-income individuals (poverty-income ratio < 1) had 1.22 (95% CI 1.04-1.44) and 2.08 (95% CI 1.61-2.67) higher prevalence of insufficient sleep as compared to high income individuals on workday and non-workdays, respectively. In general, we found larger differences by level of SES indicator for the non-workday than for the workday outcome. There were no major differences in gender-stratified analysis. We also found that lower SES was associated with higher prevalence of excessive sleep (≥ 9 h).

CONCLUSION

Socioeconomic status indicators are significantly associated with sleep duration in the US adult population. Lower SES correlates with increased prevalence of insufficient sleep duration, which has implications for the overall wellbeing of US adults with lower SES. Targeted interventions and further research are needed to reduce this disparity.

Discrimination and sleep disturbance among older Black Americans: A longitudinal analysis of the Health and Retirement Study

OBJECTIVES

Black and older adults have higher risk for sleep problems than their White and younger counterparts. Yet, our understanding of the determinants of sleep problems specifically among older Black adults is severely limited. The aim of this study was to determine whether everyday and major discrimination are longitudinally associated with sleep disturbance in a nationally representative sample of older Black adults.

METHODS

Non-Latinx Black respondents aged 51+ were selected from waves 8 (2006) through 15 (2020) of the Health and Retirement Study (baseline N = 1397). Sleep disturbance was measured with the 4-item Jenkins Sleep Questionnaire. The 6-item Everyday Discrimination Scale was used to measure everyday discrimination, and the Major Experiences of Discrimination Scale was used to measure major discrimination. Analyses controlled for sociodemographics, health behaviors, and health conditions. Lagged mixed-effects linear regression models were performed to test the longitudinal associations between baseline discrimination and sleep disturbance over 12years.

RESULTS

Higher baseline everyday discrimination was longitudinally associated with more severe sleep disturbance. Compared to respondents who reported no major discrimination at baseline, those who reported two or more major discrimination experiences had more severe sleep disturbance over time.

CONCLUSIONS

This study provides critical information on the possible longitudinal drivers of sleep disparities at the population level. This information has implications for better understanding the mechanisms of health disparities and for attaining health equity.

Associations of Everyday Discrimination With Insomnia and Short Sleep Duration Among Older Women

BACKGROUND

Discrimination may contribute to sleep health disparities among women, yet limited research has investigated the association between discrimination and insomnia with short sleep.

METHODS AND RESULTS

Among a racially and ethnically diverse sample of women (N=25 920; mean age, 72.2±6.1 years), we investigated the relationship of discrimination with insomnia symptoms and sleep duration. Poisson models with robust variance were fit to examine discrimination with insomnia, sleep duration (short <7 hours or long >9 hours versus recommended 7-9 hours), and insomnia short sleep phenotype adjusted for covariates. Insomnia symptoms, short and long sleep, and high discrimination were reported by 53%, 11%, 15%, and 40% of women, respectively. Women reporting high versus low discrimination were more likely to report insomnia, short sleep, and insomnia short sleep phenotype (insomnia: adjusted prevalence ratio, 1.15 [95% CI, 1.13-1.18]; short sleep: adjusted prevalence ratio, 1.24 [95% CI, 1.16-1.34]; insomnia short sleep phenotype: adjusted prevalence ratio, 1.45 [95% CI, 1.31-1.61]). In exploratory analyses, the association between discrimination and insomnia symptoms was present among Asian and White women, whereas the association between discrimination and sleep duration was among Hispanic (long sleep) and White (short sleep) women. Further, the association between discrimination and insomnia symptoms was more pronounced among those with less than a bachelor's degree, whereas women with a bachelor's degree or higher were less vulnerable to the association between discrimination and long sleep.

CONCLUSIONS

Discrimination was associated with insomnia and short sleep, a more severe phenotype for adverse cardiovascular health. Discrimination may be a target for reducing sleep problems among older women.

Day-to-day associations of intersectional minority stressors with sleep health in sexual and gender minority people of color

OBJECTIVE

To determine the day-to-day associations between minority stressors (i.e., anticipated and experienced discrimination) and sleep health outcomes (i.e., total sleep time (TST), sleep disturbances, and sleep-related impairment) among sexual and gender minority (SGM) people of color.

METHOD

An online sample of SGM people of color living in the United States participated in a 30-day daily diary study. Daily anticipated and experienced discrimination as well as subjective sleep outcomes were assessed via electronic diaries using validated measures. Wrist-worn actigraphy was used to objectively assess TST. Multilevel linear models (MLMs) were used to estimate the independent associations of daily intersectional minority stressors with subsequent sleep outcomes, adjusted for demographic factors and lifetime discrimination.

RESULTS

The sample included 43 SGM people of color with a mean age of 27.0 years (± 7.7) of which 84% were Latinx, 47% were multiracial, and 37% were bisexual. Results of MLMs indicated that greater report of daily experienced discrimination was positively associated with same-night sleep disturbances, B (SE) = 0.45 (0.10), p < .001. Daily anticipated discrimination was positively associated with sleep-related impairment on the following day, B (SE) = 0.77 (0.17), p < .001. However, daily anticipated and experienced discrimination were not associated with same-night TST.

CONCLUSIONS

Findings highlight the importance of considering the differential effects of daily intersectional minority stressors on the sleep health of SGM people of color. Further research is needed to identify factors driving the link between daily minority stressors and sleep outcomes to inform sleep health interventions tailored to this population. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Rumination mediates associations between microaggressions and sleep quality in Black Americans: the toll of racial microstressors

Disparities in health outcomes between Black and White Americans are well-documented, including sleep quality, and disparities in sleep may lead to disparities in health over the life course. A meta-model indicates that cognitive processes may underly the connection between race and poor sleep quality, and ultimately, health disparities. That is, there are race-specific stressors that disproportionately affect Black Americans, which are associated with poor health through biological, cognitive, and behavioral mechanisms (e.g., sleep). Among these race-specific stressors is discrimination, which has been linked to poor sleep quality, and there is a body of literature connecting perseverative cognition (e.g., rumination and worry or vigilance) to poor sleep. Microaggressions, a more subtle but pervasive form of discrimination, are another race-specific stressor. Although less research has considered the connection of microaggressions to perseverative cognition, there are some studies linking microaggressions to health outcomes and sleep. Therefore, using a cross-sectional survey, we tested the following hypotheses: racism-related vigilance and rumination would mediate the relationship between discrimination and poor sleep as well as between microaggressions and poor sleep among Black Americans (N = 223; mean age = 35.77 years, 53.8% men, 86% employed, 66.8% with college degree or higher education). Results of seven parallel mediation models showed that neither rumination nor racism-related vigilance mediated a relationship between discrimination and poor sleep quality. However, rumination partially mediated relationships between the six microaggression sub-scales and poor sleep quality: there were significant indirect effects for Foreigner/Not Belonging (β = .13, SE = 0.03, 95% CI 0.08, 0.20), Criminality (β = .11, SE = 0.03, 95% CI 0.05, 0.17), Sexualization (β = .10, SE = 0.03, 95% CI 0.05, 0.17), Low-Achieving/Undesirable (β = .10, SE = 0.03, 95% CI 0.05, 0.15), Invisibility (β = .15, SE = 0.04, 95% CI 0.08, 0.23), and Environmental Invalidations (β = .15, SE = 0.04, 95% CI 0.08, 0.23). Overall, these findings indicate support for the meta-model, demonstrating a specific pathway from racial microstressors to poor sleep quality. Furthermore, these results suggest the importance of developing clinical and community approaches to address the impact of microaggressions on Black Americans' sleep quality.

Do Sleep Problems Exacerbate the Mental Health Consequences of Discrimination Among Adults?

OBJECTIVE

An emerging literature suggests that sleep may play an important role in moderating the association between discrimination and mental health problems among adolescents. However, few if any studies have considered this topic among adults. Addressing this knowledge gap, the current study examined multiple sleep parameters as moderating variables in the association between discrimination and mental health problems among adults.

METHODS

Participants were 874 adults residing in small towns and semirural contexts within the Southeastern region of the United States ( Mage = 41 years, SD = 7; 57% female; 31% Black, 69% White; 52% income-to-needs < 2). Sleep duration and night-to-night variability in duration were assessed using wrist actigraphy. Established self-report measures were used to assess global sleep problems, experiences of discrimination, and mental health problems (anxiety, depression, and externalizing symptoms).

RESULTS

Experiences of discrimination were associated with more depression, anxiety, and externalizing problems. Two out of three sleep parameters were found to moderate the effects of discrimination on mental health. The association between discrimination and externalizing problems (but not anxiety or depression) was attenuated among those with less night-to-night variability in sleep duration. The associations between discrimination and anxiety and externalizing problems (but not depression) were attenuated among those with fewer global sleep problems. Less variability in sleep duration and fewer global sleep problems were also directly associated with lower levels of depression, anxiety, and externalizing problems.

CONCLUSIONS

Greater consistency in sleep duration from night-to-night, and fewer overall sleep problems appear to mitigate risk of mental health problems among adults, particularly in contexts where discrimination is prevalent.

Officer-Involved Killings of Unarmed Black People and Racial Disparities in Sleep Health

Importance

Racial disparities in sleep health may mediate the broader health outcomes of structural racism.

Objective

To assess changes in sleep duration in the Black population after officer-involved killings of unarmed Black people, a cardinal manifestation of structural racism.

Design, Setting, and Participants

Two distinct difference-in-differences analyses examined the changes in sleep duration for the US non-Hispanic Black (hereafter, Black) population before vs after exposure to officer-involved killings of unarmed Black people, using data from adult respondents in the US Behavioral Risk Factor Surveillance Survey (BRFSS; 2013, 2014, 2016, and 2018) and the American Time Use Survey (ATUS; 2013-2019) with data on officer-involved killings from the Mapping Police Violence database. Data analyses were conducted between September 24, 2021, and September 12, 2023.

Exposures

Occurrence of any police killing of an unarmed Black person in the state, county, or commuting zone of the survey respondent's residence in each of the four 90-day periods prior to interview, or occurence of a highly public, nationally prominent police killing of an unarmed Black person anywhere in the US during the 90 days prior to interview.

Main Outcomes and Measures

Self-reported total sleep duration (hours), short sleep (<7 hours), and very short sleep (<6 hours).

Results

Data from 181 865 Black and 1 799 757 White respondents in the BRFSS and 9858 Black and 46 532 White respondents in the ATUS were analyzed. In the larger BRFSS, the majority of Black respondents were between the ages of 35 and 64 (99 014 [weighted 51.4%]), women (115 731 [weighted 54.1%]), and college educated (100 434 [weighted 52.3%]). Black respondents in the BRFSS reported short sleep duration at a rate of 45.9%, while White respondents reported it at a rate of 32.6%; for very short sleep, the corresponding values were 18.4% vs 10.4%, respectively. Statistically significant increases in the probability of short sleep and very short sleep were found among Black respondents when officers killed an unarmed Black person in their state of residence during the first two 90-day periods prior to interview. Magnitudes were larger in models using exposure to a nationally prominent police killing occurring anywhere in the US. Estimates were equivalent to 7% to 16% of the sample disparity between Black and White individuals in short sleep and 13% to 30% of the disparity in very short sleep.

Conclusions and Relevance

Sleep health among Black adults worsened after exposure to officer-involved killings of unarmed Black individuals. These empirical findings underscore the role of structural racism in shaping racial disparities in sleep health outcomes.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Socioeconomic status, mental health, and nutrition are the principal traits for low back pain phenotyping: Data from the osteoarthritis initiative

Background

Low back pain (LBP) is a heterogeneous disease with biological, physical, and psychosocial etiologies. Models for predicting LBP severity and chronicity have not made a clinical impact, perhaps due to difficulty deciphering multidimensional phenotypes. In this study, our objective was to develop a computational framework to comprehensively screen metrics related to LBP severity and chronicity and identify the most influential.

Methods

We identified individuals from the observational, longitudinal Osteoarthritis Initiative cohort (N = 4796) who reported LBP at enrollment (N = 215). OAI descriptor variables (N = 1190) were used to cluster individuals via unsupervised learning and uncover latent LBP phenotypes. We also developed a dimensionality reduction algorithm to visualize clusters/phenotypes using Uniform Manifold Approximation and Projection (UMAP). Next, to predict chronicity, we identified those with acute LBP (N = 40) and persistent LBP over 8 years of follow-up (N = 66) and built logistic regression and supervised machine learning models.

Results

We identified three LBP phenotypes: a "high socioeconomic status, low pain severity group", a "low socioeconomic status, high pain severity group", and an intermediate group. Mental health and nutrition were also key clustering variables, while traditional biomedical factors (e.g., age, sex, BMI) were not. Those who developed chronic LBP were differentiated by higher pain interference and lower alcohol consumption (a correlate to poor physical fitness and lower soceioeconomic status). All models for predicting chronicity had satisfactory performance (accuracy 76%-78%).

Conclusions

We developed a computational pipeline capable of screening hundreds of variables and visualizing LBP cohorts. We found that socioeconomic status, mental health, nutrition, and pain interference were more influential in LBP than traditional biomedical descriptors like age, sex, and BMI.

Gendered Racial Microaggressions and Black Women's Sleep Health

Gendered racial microaggressions reflect historical and contemporary gendered racism that Black women encounter. Although gendered racial microaggressions are related to psychological outcomes, it is unclear if such experiences are related to sleep health. Moreover, the health effects of gendered racial microaggressions dimensions are rarely investigated. Using a cohort of Black women (N = 400), this study employs an intracategorical intersectional approach to (1) investigate the association between gendered racial microaggressions and sleep health, (2) assess whether gendered racial microaggressions dimensions are related to sleep health, and (3) examine whether the gendered racial microaggressions-sleep health association persists after accounting for depressive symptoms and worry. Gendered racial microaggressions were associated with poor sleep quality overall and four specific domains: subjective sleep quality, latency, disturbance, and daytime sleepiness. Two gendered racial microaggressions dimensions were especially detrimental for sleep: assumptions of beauty/sexual objectification and feeling silenced and marginalized. After accounting for mental health, the effect of gendered racial microaggressions on sleep was reduced by 47 percent. Future research implications are discussed.

Discrimination and Sleep: Differential Effects by Type and Coping Strategy

BACKGROUND

Discrimination has been posited as a contributor of sleep disparities for Latinxs. The strategy used to cope with discrimination may reduce or exacerbate its effects on sleep. This study examined whether different types of discrimination (everyday and major lifetime discrimination) were associated with sleep indices (quality, disturbances, efficiency) and whether coping strategy used moderated associations.

METHOD

Data of Latinx adults (N = 602; 51% women, 65% Dominican, Mage = 46.72 years) come from the Latino Health and Well-being Project, a community-based, cross-sectional study of Latinxs in Lawrence, MA. Multiple linear regressions were estimated separately for each sleep outcome.

RESULTS

Everyday discrimination was significantly associated with poorer sleep quality and greater disturbances; major lifetime discrimination was significantly associated with worse sleep across the three sleep indices. Coping strategy moderated associations between discrimination and sleep. Compared with Latinxs who used passive coping, those who used passive-active coping strategies had poorer sleep quality the more they experienced everyday discrimination. Latinxs who used any active coping strategy, compared with passive coping, had greater sleep disturbances the more frequently they experienced major lifetime discrimination.

CONCLUSIONS

Findings show that everyday discrimination and major lifetime discrimination are associated with different dimensions of sleep and suggest that coping with discrimination may require the use of different strategies depending on the type of discrimination experienced.

Racial Disparities in Sleep: Potential Mediation by Discrimination and Psychological Distress

Previous research has demonstrated that experiences of discrimination contribute to racial disparities in sleep, and that psychological distress mediates these relationships. However, previous research has not included race as part of the mediation pathway and has had limited dimensions of sleep health and psychological mediators. In the current study, we examine serial mediation pathways by which race and sleep health are mediated through discrimination and subsequently through psychological distress (i.e., depressive symptoms, chronic stress, and loneliness). Data were from the 2010 wave of the Health Retirement Study (HRS). The analytic sample (n = 7,749) included Black and White participants who were included in the enhanced face-to-face interview in 2010 and who completed the psychosocial questionnaire. Race was reported as either Black or White. Sleep health was assessed with a 4-item questionnaire. Depressive symptoms were assessed with the shortened CES-D, chronic stress via the ongoing chronic stressor scale, and loneliness via the UCLA loneliness scale. Covariates were included in all serial mediation models. Relative to White participants, Black participants reported increased experiences of discrimination, which was associated with increased psychological distress, and poorer sleep health. Findings demonstrate the significant adverse impact that discrimination has on both psychological well-being and sleep health.

Longitudinal association between perceived discrimination and sleep problems among young adults in the United States: Tests of moderation by race/ethnicity and educational attainment

RATIONALE

Although perceived discrimination is known to affect sleep, the findings of previous research are limited because they are mostly based on either cross-sectional data or non-generalizable samples, such as clinical samples. There is also little evidence on whether perceived discrimination differently affects sleep problems across different groups.

OBJECTIVE

This study examines whether perceived discrimination is related to sleep problems when considering unmeasured confounding factors and how that relationship varies by race/ethnicity and socioeconomic status from a longitudinal perspective.

METHODS

This study uses Waves 1, 4, and 5 of the National Longitudinal Study of Adolescent to Adult Health (Add Health) and conducts hybrid panel modeling to estimate both within- and between-individual effects of perceived discrimination on sleep problems.

RESULTS

First, the results of the hybrid modeling show that increased perceived discrimination in daily life is related to poorer sleep quality when accounting for unobserved heterogeneity as well as time-constant and time-varying covariates. Moreover, the moderation analyses and the subgroup analyses demonstrate that the association was not found among Hispanics and among those with a bachelor's degree or more. That is, Hispanic origin and college attainment weaken the associations between perceived discrimination and sleep problems, and the differences by race/ethnicity and socioeconomic status are statistically significant.

CONCLUSIONS

This study suggests a robust link between discrimination and sleep problems and further elaborates on whether this association varies among different groups. Efforts to reduce interpersonal and institutional discrimination (e.g., discrimination at the workplace or in the community) can help to improve sleep problems and thereby promote overall health. We also suggest that future research consider the moderating roles of susceptible and resilient factors in the relationships between discrimination and sleep.

Discrimination and insomnia: Examining depressive symptoms and nicotine withdrawal through a serial mediation model in a sample of smokers

Insomnia is a common sleep disorder associated with poor health outcomes. Individuals from racially underrepresented groups as well as women tend to report more severe insomnia symptoms, and frequent experiences of discrimination have been found to drive such disparities. Smokers commonly experience sleep problems since nicotine can alter the sleep-wake cycle. Discrimination is associated with increased nicotine dependence, and such discrimination may also intensify tobacco withdrawal, specifically mood and cognitive-related aspects of withdrawal. The potential impact of discrimination on withdrawal symptoms and related mood symptoms like depression may lead to increases in insomnia symptoms. However, no studies to date have evaluated the indirect association of discrimination with insomnia severity through nicotine withdrawal and depressive symptoms. Therefore, this cross-sectional survey of n = 110 non-Hispanic Black and White current smokers (48.2 % Black, 69.1 % women) investigated these associations through a serial mediation model. Controlling for race, gender, nicotine dependence levels, and income, multivariate analyses supported a significant indirect effect of discrimination on insomnia severity through depressive symptoms. Analyses supported the hypothesized serial mediation model whereby discrimination is positively associated with depressive symptoms, which in turn are linked to more severe nicotine withdrawal, leading to greater insomnia severity. Smokers encountering frequent experiences of discrimination might be at increased risk of suffering insomnia as a result of their increased depressive and withdrawal symptoms. Future work is necessary to understand the role of depressive symptoms in these associations as well as possible implications for smoking relapse and success of smoking cessation programs.

Preliminary Evidence for the Sequentially Mediated Effect of Racism-Related Stress on Pain Sensitivity Through Sleep Disturbance and Corticolimbic Opioid Receptor Function

Sleep disturbance predicts worse pain outcomes. Because sleep disturbance inequitably impacts Black adults - with racism as the upstream cause - understanding how racism-related stress impacts pain through sleep might help minimize racialized pain inequities. This preliminary study examined sequential mediation of the effect of racism-related stress on experimental pain through sleep disturbance and corticolimbic μOR function in pain-free non-Hispanic Black (NHB) and White (NHW) adults. Participants completed questionnaires, actigraphy, positron emission tomography, and sensory testing. We reproduced findings showing greater sleep disturbance and pain sensitivity among NHB participants; greater sleep disturbance (r = .35) and lower pain tolerance (r=-.37) were significantly associated with greater racism-related stress. In a sequential mediation model, the total effect of racism-related stress on pain tolerance (β=-.38, P = .005) weakened after adding sleep disturbance and ventromedial prefrontal cortex (vmPFC) μOR binding potential (BPND) as mediators (β = -.18, P = .16). The indirect effect was statistically significant [point estimate = -.003, (-.007, -.0003). Findings showed a potential sequentially mediated effect of racism-related stress on pain sensitivity through sleep disturbance and vmPFC μOR BPND. As policy efforts are enacted to eliminate the upstream cause of systemic racism, these results cautiously suggest that sleep interventions within racism-based trauma informed therapy might help prevent downstream effects on pain. PERSPECTIVE: This preliminary study identified the effect of racism-related stress on pain through sleep disturbance and mu-opioid receptor binding potential in the ventromedial prefrontal cortex. Findings cautiously support the application of sleep interventions within racism-based trauma-informed therapy to prevent pain inequities as policy changes function to eliminate all levels of racism.

Circadian Rhythm Disruption as a Contributor to Racial Disparities in Prostate Cancer

In the United States, African American (AA) men have a 2.4 times higher mortality rate due to prostate cancer than White men. The multifactorial causes of the racial disparities in prostate cancer involve various social determinants of health, socioeconomic status, and access to healthcare. However, emerging evidence also suggests that circadian rhythm disruption (CRD) contributes to prostate cancer, and AA men may be more susceptible to developing CRDs. Circadian rhythms play a significant role in metabolism, hormone secretion, and sleep/wake cycles. Disruption in these circadian rhythms can be caused by airplane travel/jetlag, night shift work, exposure to light, and neighborhood noise levels, which can contribute to sleep disorders and chronic conditions such as obesity, diabetes, cardiovascular disease, and depression. The drivers of the racial disparities in CRD include night shift work, racial discrimination, elevated stress, and residing in poor neighborhoods characterized by high noise pollution. Given the increased vulnerability of AA men to CRDs, and the role that CRDs play in prostate cancer, elucidating the clock-related prostate cancer pathways and their behavior and environmental covariates may be critical to better understanding and reducing the racial disparities in prostate cancer.

Associations of circadian rest/activity rhythms with cognition in middle-aged and older adults: Demographic and genetic interactions

Objectives

Wrist actigraphs (accelerometers) can record motor activity over multiple days and nights. The resulting data can be used to quantify 24-h activity profiles, known as circadian rest-activity rhythms (CRARs). Actigraphic CRARs have been tied to cognitive performance and decline in older adults; however, little is known about links between CRARs and performance or change in specific cognitive domains, or how individual differences may influence these associations. We investigated associations of actigraphic CRARs with cognitive performance and change in middle-aged and older adults, and explored whether age, sex/gender, race, and apolipoprotein E (APOE) e4 carrier status moderated these associations.

Materials and methods

Participants (N = 422; 47% male) were cognitively healthy adults (i.e., without mild cognitive impairment or dementia) at baseline aged ≥ 50 years from the Baltimore Longitudinal Study of Aging who completed 5.6 ± 0.89 nights of wrist actigraphy and tests of memory, executive function, attention, language, and visuospatial ability at the same visit the actigraph was issued; 292 participants had repeat cognitive testing 3.12 (1.58) years later. Predictors included indices of rhythm strength [i.e., amplitude; relative amplitude (RA); interdaily stability (IS); mesor], delayed timing of the rhythm peak [i.e., later acrophase; midpoint of an individual's least active 5 h (L5 time); midpoint of an individual's most active 10 h (M10 time)], and fragmentation [i.e., intradaily variability (IV)].

Results

In main effects, later L5 time was cross sectionally associated with poorer memory, and greater IS predicted slower longitudinal memory decline. Associations of CRARs with cognition differed as a function of age, sex/gender, race, and APOE e4 carrier status.

Conclusion

Among middle-aged and older adults, delayed circadian phase is associated with poorer memory performance, and greater day-to-day rhythm stability is associated with slower declines in memory. Significant interactions suggest that CRARs are generally more strongly associated with cognitive performance and rate of cognitive decline among women, Black adults, older individuals, and APOE e4 carriers. Replication in independent samples is needed.

Chronoradiobiology of Breast Cancer: The Time Is Now to Link Circadian Rhythm and Radiation Biology

Circadian disruption has been linked to cancer development, progression, and radiation response. Clinical evidence to date shows that circadian genetic variation and time of treatment affect radiation response and toxicity for women with breast cancer. At the molecular level, there is interplay between circadian clock regulators such as PER1, which mediates ATM and p53-mediated cell cycle gating and apoptosis. These molecular alterations may govern aggressive cancer phenotypes, outcomes, and radiation response. Exploiting the various circadian clock mechanisms may enhance the therapeutic index of radiation by decreasing toxicity, increasing disease control, and improving outcomes. We will review the body’s natural circadian rhythms and clock gene-regulation while exploring preclinical and clinical evidence that implicates chronobiological disruptions in the etiology of breast cancer. We will discuss radiobiological principles and the circadian regulation of DNA damage responses. Lastly, we will present potential rational therapeutic approaches that target circadian pathways to improve outcomes in breast cancer. Understanding the implications of optimal timing in cancer treatment and exploring ways to entrain circadian biology with light, diet, and chronobiological agents like melatonin may provide an avenue for enhancing the therapeutic index of radiotherapy.