Habitual sleep as a contributor to racial differences in cardiometabolic risk

Racial and ethnic sleep health disparities in adolescents and risk for type 2 diabetes: a narrative review

INTRODUCTION

Sleep is an essential factor for health and wellbeing in people across the age spectrum; yet many adolescents do not meet the recommended 8-10 h of nightly sleep. Unfortunately, habitually insufficient sleep, along with the metabolic changes of puberty, puts adolescents at increased risk for a host of adverse health outcomes such as obesity and type 2 diabetes (T2D). Furthermore, individuals from historically minoritized racial and ethnic groups (e.g. Hispanic/Latinx, African American/Black) are more likely to experience shorter sleep duration compared to adolescents of White/European origin, placing them at even greater risk for disparities in T2D risk.

METHODS

We conducted a literature review on the role of race and ethnicity in adolescent sleep health and its relation to cardiometabolic outcomes, specifically T2D. We use the minority stress model and the stress and coping theory as guiding theoretical frameworks to examine individual and societal level factors that may contribute to sleep health disparities and their downstream effects on T2D risk.

RESULTS

This review highlights that the unique race-related stressors adolescents from minoritized groups face may play a role in the sleep and T2D connection on a biological, psychological, and social level. However, although there has been advancement in the current research on adolescent racial and ethnic sleep health disparities in relation to T2D, mechanisms underlying these disparities in sleep health need further investigation. Addressing these gaps is crucial for identifying and mitigating sleep health disparities and T2D among racial and ethnic minority youth.

CONCLUSION

We conclude with a discussion of the implications and future research directions of racial and ethnic disparities in sleep health and T2D prevention research. A comprehensive understanding of adolescent sleep health disparities has potential to better inform preventative and educational programs, interventions, and policies that promote sleep health equity and improve cardiometabolic outcomes like T2D.

The Need for Social and Environmental Determinants of Health Research to Understand and Intervene on Racial/Ethnic Disparities in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), a sleep-disordered breathing (SDB) disorder, affects at least 25 million adults in the United States and is associated with increased risk for hypertension, diabetes, and cardiovascular disease (CVD). Racial/ethnic minorities have a disproportionate burden of OSA along with the health sequelae associated with this condition. Despite supporting evidence of racial/ethnic disparities, few studies have investigated SDB including OSA among minoritized racial/ethnic groups. In this scoping review of the literature, the authors summarize current findings related to racial/ethnic disparities in OSA, identified social and environmental determinants of health, treatment inequities, and promising evidence-based interventions and conclude with future research directions.

Differences in Emotion Expression, Suppression, and Cardiovascular Consequences Between Black and White Americans in the Midlife in the United States (MIDUS) Study

OBJECTIVE

Recent theoretical work suggests that the expression of emotions may differ among Black and White Americans, such that Black Americans engage more frequently in expressive suppression to regulate emotions and avoid conflict. Prior work has linked expressive suppression usage with increases in cardiovascular disease risk, suggesting that racialized differences in expressive suppression usage may be one mechanism by which racism "gets under the skin" and creates health disparities.

METHOD

To examine racialized differences in expressive suppression and blood pressure (a measure of cardiovascular disease risk), we used self-report and facial electromyography (fEMG) data from two cohorts of Black and White Americans from the Midlife in the United States (MIDUS) longitudinal study (MIDUS 2, n = 271, 34.7% Black, collected from 2004 to 2009; MIDUS Refresher 1, n = 114, 31.6% Black, collected from 2012 to 2016; total N = 385, 33.9% Black).

RESULTS

Black Americans reported engaging in expressive suppression more frequently than White Americans ( t (260.95) = 2.18, p = .002) and showed less corrugator fEMG activity during negative images ( t (969) = 2.38, pFDR = .026). Less corrugator activity during negative images was associated with higher systolic blood pressure only for Black Americans ( b = -4.63, t (375) = 2.67, p = .008).

CONCLUSION

Overall, results are consistent with theoretical accounts that Black Americans engage more frequently in expressive suppression, which in turn is related to higher cardiovascular risk. Additional research is needed to further test this claim, particularly in real-world contexts and self-reports of in-the-moment usage of expressive suppression.

The Relationship between Sleep and Physical Activity by Age, Race, and Gender

Cardiometabolic diseases remain the leading cause of death in the United States. Lifestyle factors contribute the majority of risk for these diseases. Although diet and exercise have been the primary focus of research on modifiable behaviors to target for interventions to prevent cardiometabolic disease, recent evidence suggests that sleep also plays an important role. Indeed, the updated American Heart Association campaign includes sleep as one of its "Essential Eight". This review details the reciprocally reinforcing positive relationship between sleep and daytime physical activity behaviors and explores how this relationship differs based on age, gender and race. For example, interventions to improve moderate intensity physical activity may be particularly beneficial to women, older adults, and Black Americans, who are at increased risk for sleep disturbances. Communicating to Americans the importance of managing their time to meet current physical activity and sleep recommendations is a challenge given that there are so many competing behaviors consuming large amounts of time (e.g., social media, gaming), but is critical given the importance of these behaviors for cardiometabolic health.

CARDIA sleep ancillary study: study design and methods

Sleep and circadian disturbances are common and are experienced more often by Black compared to White individuals. We conducted an observational study of sleep that was ancillary to an ongoing cohort study, Coronary Artery Disease in Young Adults (CARDIA). The goal of the ancillary study will be to examine potential determinants of sleep/circadian disparities between Black and White adults in future analyses. Herein we describe the study design and methodology. Our ancillary study coincided with the Year 35 examination of the CARDIA study and was conducted in two phases (due to the SARS-COV-2 pandemic). Phase 1 involved only questionnaires to assess chronotype, restless legs syndrome, and the household sleep environment. Phase 2 involved three additional questionnaires to assess sleep quality, daytime sleepiness and insomnia symptoms, as well as two sleep devices. Participants wore a wrist activity monitor to assess sleep-wake patterns and light levels for 7 days and a home sleep apnea test for 1 night. A subset also had devices objectively record light, temperature, and sound levels in their bedrooms for 7 days. Sample sizes ranged based on assessment from 2200 to 2400, completing Phase 1 questionnaires, 899 with valid wrist actigraphy data, and 619 with a valid sleep apnea test. The data will be part of the full CARDIA dataset, which is available to researchers.

Local gun violence, mental health, and sleep: A neighborhood analysis in one hundred US Cities

RATIONALE

Community gun violence significantly shapes public health and collective well-being. Understanding how gun violence is associated with community health outcomes like mental health and sleep is crucial for developing interventions to mitigate disparities exacerbated by violence exposure.

OBJECTIVE

This study examines the associations between community gun violence , insufficient sleep, and poor mental health across neighborhoods in the United States.

METHODS

We utilized a novel database covering nearly 16,000 neighborhoods in 100 US cities from 2014 through 2019. Correlated trait fixed-effects models were employed to conduct all analyses while considering various neighborhood covariates such as concentrated disadvantage, demographic composition, population density, and proximity to trauma centers.

RESULTS

Our analysis revealed that greater gun violence is associated with both insufficient sleep and poor mental health in subsequent years. There is a reciprocal relationship between poor mental health and insufficient sleep, with each partially mediating the other's association with community gun violence. Notably, gun violence exhibits the strongest direct association with poor sleep rather than with poor mental health. We found a consistent reciprocal relationship between sleep and mental health at the community level.

CONCLUSIONS

The findings highlight a complex interplay between community violence, sleep, and mental health, underlining the importance of reducing community violence through numerous long-term interventions to address health disparities across the US.

Neighborhood Light at Night and Noise Levels, and Long-Term Sleep Trajectories in the Southern Community Cohort Study

While light at night (LAN) and noise levels have been linked to suboptimal sleep outcomes, little is known about the link between these factors and long-term suboptimal sleep trajectories. The current study examined the association of neighborhood LAN and nighttime noise with long-term sleep trajectories in a cohort of Black individuals and White individuals predominantly from low-income communities. We used data from the Southern Community Cohort Study (N = 28,759 Black individuals and 16,276 White individuals). Sleep duration was self-reported at baseline and after an average of five years of follow-up, based on which we constructed nine sleep trajectories: normal-normal (optimal, reference), short-short, long-long, short-long, long-short, normal-short, normal-long, short-normal, and long-normal. LAN and nighttime noise were derived from satellite imagery and model-based estimates, respectively. Multinomial logistic regression was used to determine the relationship between LAN and noise exposures and sleep trajectories. Higher exposures to LAN and nighttime noise were associated with multiple suboptimal long-term sleep trajectories. In the total sample, higher LAN was associated with higher odds of long-long (OR Q5 vs. Q1 = 1.23 (CI = 1.02, 1.48)) and long-short (OR = 1.35 (CI = 1.06, 1.72)) trajectories, while higher nighttime noise was associated with short-short (1.19 (1.07, 1.31)), long-short (1.31 (1.05, 1.64)), and normal-song (1.16 (1.01, 1.34)) trajectories. Black and White individual-specific results showed qualitatively similar patterns between Black individuals and White individuals, although we also observed suggestive evidence for Black-White individual differences. In conclusion, elevated LAN and nighttime noise levels were associated with various suboptimal long-term sleep trajectories. However, it is noteworthy that the light and noise measures in our study may not accurately reflect individual-level exposures, and residual confounding from other factors is a concern. Future studies should use more accurate exposure measurements, collect information on and control for a wider range of factors, and examine whether reductions in neighborhood light and noise levels may contribute to improved long-term sleep health.

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.

Racial/ethnic and sex differences in the association between light at night and actigraphy-measured sleep duration in adults: NHANES 2011-2014

OBJECTIVE

Historically minoritized individuals experience greater exposure to light at night, yet it is unclear whether the association between light at night and sleep duration vary by race/ethnicity or sex. We examined the association between light at night and sleep duration by race/ethnicity and sex.

METHODS

Participants (N = 6089, mean age=49.5, 52% women, 13% Asian, 27% Black, 14% Mexican, 46% White) in the 2011-2014 National Health and Nutrition Examination Survey underwent 9-day of actigraphy. Light at night was defined as light exposure within the 5-hour activity nadir (L5). Sleep duration within a 24-hour period was analyzed as short (<7 hours) or long (>9 hours) compared to recommended (≥7 and <9 hours). Poisson models were fit to estimate the association between light at night and sleep duration after adjustment for covariates.

RESULTS

Light at night was most common among Black participants, who also had the shortest sleep duration. Overall, light at night was associated with 80% higher prevalence of short sleep duration [1.80 (1.49, 2.18)]. Compared to no-light at night, low and high light at night were associated with higher prevalence of short sleep duration, [1.61 (1.31, 1.98) and 2.01 (1.66, 2.44), respectively]. Associations varied by race/ethnicity and sex. Light at night was associated with shorter sleep duration in Black, Mexican and White females and Mexican and White males only. Black males exposed to light at night vs. no-light at night had lower prevalence of long sleep duration. There were no associations between light at night and sleep duration among Asian participants.

CONCLUSION

Light at night was associated with shorter sleep duration, particularly among females. Targeting light exposure may help to improve sleep duration.

The effects of sleep disruption on metabolism, hunger, and satiety, and the influence of psychosocial stress and exercise: A narrative review

Sleep deficiency is a ubiquitous phenomenon among Americans. In fact, in the United States, ∼78% of teens and 35% of adults currently get less sleep than recommended for their age-group, and the quality of sleep appears to be getting worse for many. The consequences of sleep disruption manifest in a myriad of ways, including insulin resistance and disrupted nutrient metabolism, dysregulation of hunger and satiety, and potentially increased body weight and adiposity. Consequently, inadequate sleep is related to an increased risk of various cardiometabolic diseases, including obesity, diabetes, and heart disease. Exercise has the potential to be an effective therapeutic to counteract the deleterious effects of sleep disruption listed above, whereas chronic psychosocial stress may causally promote sleep disruption and cardiometabolic risk. Here, we provide a narrative review of the current evidence on the consequences of short sleep duration and poor sleep quality on substrate metabolism, circulating appetite hormones, hunger and satiety, and weight gain. Secondly, we provide a brief overview of chronic psychosocial stress and its impact on sleep and metabolic health. Finally, we summarise the current evidence regarding the ability of exercise to counteract the adverse metabolic health effects of sleep disruption. Throughout the review, we highlight areas where additional interrogation and future exploration are necessary.

Association of extreme heat events with sleep and cardiovascular health: A scoping review

BACKGROUND

Extreme heat events (EHEs), driven by anthropogenic climate change, exacerbate the risk of cardiovascular disease (CVD), although the underlying mechanisms are unclear. Disturbances in sleep health, caused by excessive heat, may be one way EHEs increase the risk of incident or recurrent CVD. Our objective was to systematically review the empirical peer-reviewed literature on the relationship between EHEs, sleep health, and cardiovascular measures and outcomes, and narratively describe methodologies, evidence, and gaps in this area.

METHODS

A comprehensive literature search was performed in the following databases from inception - June 2023: Ovid MEDLINE, Ovid EMBASE, CINAHL, Web of Science and The Cochrane Library. Studies retrieved were then screened for eligibility against predefined inclusion/exclusion criteria.

RESULTS

Of the 2035 records screened, three studies met the inclusion criteria. Cardiovascular (CV) measures described included blood pressure (BP), heart rate (HR), and HR variability (no CVD outcomes were described) and objective and subjective measurements of sleep health outcomes included sleep duration, calmness, ease of falling asleep, ease of awakening, freshness after awakening, and sleep satisfaction. Two studies were controlled trials, and one was a cohort study. During EHEs, individuals slept for shorter periods of time and less efficiently, with greater degrees of HR variability in two of the three studies lasting at most 1-2 days; BP (both systolic and diastolic) significantly decreased during EHEs in two of the studies. No formal assessment of a mediating relationship between EHE exposure, sleep outcomes, and the CV measures was undertaken.

CONCLUSIONS

There is a paucity of data that examines the link between CVD, sleep, and extreme heat as a possible mechanism of elevated CVD risk during EHEs, despite a strong physiological rationale. Further research is needed to empirically test this relationship rigorously as EHEs become more frequent and their deleterious impacts of health increase.

The Association Between Race, Ethnicity and Sleep Quality and Duration: A National Health Interview Survey Study

BACKGROUND

Inadequate sleep duration and poor sleep quality are associated with adverse cardiovascular outcomes.

METHODS

Using data from the National Health Interview Survey, we compared self-reported sleep duration and quality among different groups: Whites, Chinese, Asian Indian, Filipino, and Other Asians. Outcome included Sleep duration (≥7 and <7 hours) and sleep quality (coded as a binary variable).

RESULTS

We included 155,203 participants. The overall prevalence of ≥7 hours of sleep was 69.5% and poor sleep quality was reported by 73.9%. Compared to Whites and Chinese, Filipinos, and Other Asians were less likely to get adequate sleep (≥7 hours). All 4 Asian groups were less likely to report poor sleep quality compared with White individuals, while Asian Indians reported poor sleep quality less frequently compared with Chinese individuals.

CONCLUSION

There are significant differences in sleep duration and quality between White and Asian groups, as well as within Asian subgroups. Further studies with disaggregated Asian subgroup data are needed to formally study these disparities.

Not Just Time on Social Media: Experiences of Online Racial/Ethnic Discrimination and Worse Sleep Quality for Black, Latinx, Asian, and Multi-racial Young Adults

Sleep quality in young adulthood sets the stage for long-term health. Racial/ethnic sleep disparities between White college-attending young adults and college-attending young adults of color exist. The stress of experiencing racial/ethnic discrimination makes it difficult for college-attending young adults of color to get good quality sleep. Yet it remains unclear if experiencing online racial/ethnic discrimination also has consequences for sleep quality, and if this association may vary by frequency of social media use. To investigate the role of racial/ethnic discrimination on sleep quality, we conducted an online survey of 154 college-attending young adults (Mage = 19.51) who identified as Black (42.2%), Latinx (16.9%), Asian (20.8%), or Bi-/multi-racial (20.1%) from a predominantly White university. Results indicated that more exposure to racial/ethnic discrimination was associated with worse sleep quality for young adults of color. Results suggest that online racial/ethnic discrimination has a similar negative impact on sleep quality regardless of the frequency of social media use. Increased attention to negative race-related experiences online as one potential risk factor for poor long-term health for young adults of color is needed, regardless of how many hours they spend on social media. Structural interventions, screening for stress due to exposure to online racial/ethnic discrimination, and facilitating opportunities to prepare for this exposure may be an important priority for sleep health and reduction of racial/ethnic health disparities.

Racial/ethnic differences in the beneficial effect of social support on sleep duration

STUDY OBJECTIVES

Social support (SS) is associated with better health outcomes, including sleep health. However, the specific sources of SS that benefit sleep are unclear, and whether these associations vary by race/ethnicity or age is unknown. The aim of this study was to examine cross-sectional associations between sources of SS (number of friends, financial, church attendance, and emotional support) and self-reported short sleep duration (< 7 hours) overall and by race/ethnic groups and age among a representative sample.

METHODS

Using National Health and Nutrition Examination Survey (NHANES) data, logistic regression (marginal standardization) and linear regression models were fit accounting for survey design and weights to test associations between sources of SS (number of friends, financial, church attendance, emotional support) and self-reported short sleep duration (< 7 hours) overall and by race/ethnic groups (Black, Hispanic, and White) and age (< 65 vs ≥ 65 years).

RESULTS

Among 3,711 participants, the mean (standard error) age was 57 (0.3) years and 37% slept < 7 hours. Black adults had the highest prevalence of short sleep (55%). Overall, participants with financial support compared with those without financial support had a lower prevalence of short sleep: 23% (confidence interval [CI]: 0.68, 0.87). As the number of SS sources increased, the prevalence of short sleep duration decreased and the racial disparity in sleep duration narrowed. Associations between financial support and sleep were most pronounced among Hispanic and White adults and adults < 65 years.

CONCLUSIONS

In general, financial support was associated with a healthier sleep duration, particularly among those < 65 years of age. Individuals with numerous sources of SS were less likely to be short sleepers. The benefits of SS on sleep duration varied by race. Targeting specific sources of SS may help to improve sleep duration among those most at risk.

CITATION

Johnson DA, Prakash-Asrani R, Lewis BD, Bliwise DL, Lewis TT. Racial/ethnic differences in the beneficial effect of social support on sleep duration. J Clin Sleep Med. 2023;19(7):1231-1238.

Acute beetroot juice reduces blood pressure in young Black and White males but not females

A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3-)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3-) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3- were associated with reduced brachial systolic BP (ρ = -0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.

Neighborhood Built Environment and Sleep Health: A Longitudinal Study in Low-Income and Predominantly African-American Neighborhoods

In the present study, we examined the associations between physical characteristics of neighborhoods and sleep health outcomes and assessed the mediating role of physical activity in these associations. A longitudinal study (the Pittsburgh Hill/Homewood Research on Eating, Shopping, and Health (PHRESH) Zzz Study; n = 1,051) was conducted in 2 low-income, predominately African-American neighborhoods in Pittsburgh, Pennsylvania, with repeated measures of neighborhood characteristics and sleep health outcomes from 2013 to 2018. Built environment measures of walkability, urban design, and neighborhood disorder were captured from systematic field observations. Sleep health outcomes included insufficient sleep, sleep duration, wakefulness after sleep onset, and sleep efficiency measured from 7-day actigraphy data. G-computations based on structural nested mean models were used to examine the total effects of each built environment feature, and causal mediation analyses were used to evaluate direct and indirect effects operating through physical activity. Urban design features were associated with decreased wakefulness after sleep onset (risk difference (RD) = -1.26, 95% confidence interval (CI): -4.31, -0.33). Neighborhood disorder (RD = -0.46, 95% CI: -0.86, -0.07) and crime rate (RD = -0.54, 95% CI: -0.93, -0.08) were negatively associated with sleep efficiency. Neighborhood walkability was not associated with sleep outcomes. We did not find a strong and consistent mediating role of physical activity. Interventions to improve sleep should target modifiable factors, including urban design and neighborhood disorder.

Causes, Consequences, and Treatments of Sleep and Circadian Disruption in the ICU: An Official American Thoracic Society Research Statement

Background: Sleep and circadian disruption (SCD) is common and severe in the ICU. On the basis of rigorous evidence in non-ICU populations and emerging evidence in ICU populations, SCD is likely to have a profound negative impact on patient outcomes. Thus, it is urgent that we establish research priorities to advance understanding of ICU SCD. Methods: We convened a multidisciplinary group with relevant expertise to participate in an American Thoracic Society Workshop. Workshop objectives included identifying ICU SCD subtopics of interest, key knowledge gaps, and research priorities. Members attended remote sessions from March to November 2021. Recorded presentations were prepared and viewed by members before Workshop sessions. Workshop discussion focused on key gaps and related research priorities. The priorities listed herein were selected on the basis of rank as established by a series of anonymous surveys. Results: We identified the following research priorities: establish an ICU SCD definition, further develop rigorous and feasible ICU SCD measures, test associations between ICU SCD domains and outcomes, promote the inclusion of mechanistic and patient-centered outcomes within large clinical studies, leverage implementation science strategies to maximize intervention fidelity and sustainability, and collaborate among investigators to harmonize methods and promote multisite investigation. Conclusions: ICU SCD is a complex and compelling potential target for improving ICU outcomes. Given the influence on all other research priorities, further development of rigorous, feasible ICU SCD measurement is a key next step in advancing the field.

Acceptability & Usability of a Wearable Device for Sleep Health Among English- and Spanish-Speaking Patients in the Safety-Net: Qualitative Analysis

BACKGROUND

Sleep disorders are common and disproportionately affect marginalized populations. Technology such as wearable devices holds the potential to improve sleep quality and reduce sleep disparities, but most devices have not been designed or tested with racially, ethnically, and socioeconomically diverse patients. Inclusion and engagement of diverse patients throughout digital health development and implementation are critical to achieving health equity.

OBJECTIVE

This study aims to evaluate the usability and acceptability of a wearable sleep monitoring device - SomnoRing® - and its accompanying mobile application among patients treated in a safety net clinic.

METHODS

The study team recruited English- and Spanish-speaking patients from a mid-sized pulmonary and sleep medicine practice serving publicly insured patients. Eligibility criteria included initial evaluation of obstructed sleep apnea which is most appropriate for limited cardiopulmonary testing. Patients with primary insomnia or other suspected sleep disorders were not included. Patients tested the SomnoRing® over a seven-night period and participated in a one-hour semi-structured virtual qualitative interview covering perceptions of the device, motivators and barriers to use, and general experiences with digital health tools. The study team used inductive/deductive processes to code interview transcripts, guided by the Technology Acceptance Model.

RESULTS

Twenty-one individuals participated in the study. All participants owned a smartphone, almost all (19/21) felt comfortable using their phone, and few already owned a wearable (6/21). Almost all participants wore the SomnoRing® for seven nights and found it comfortable. Four themes emerged from qualitative data: 1) the SomnoRing® was easy to use compared to other wearable devices or traditional home sleep testing alternatives such as the standard polysomnogram technology for sleep studies; 2) the patient's context and environment such as family and peer influence, housing status, access to insurance, and device cost affected overall acceptance of the SomnoRing®; 3) clinical champions motivated use in supporting effective onboarding, interpretation of data, and, ongoing technical support; and 4) participants desired more assistance and information to best interpret their own sleep data summarized in the companion app.

CONCLUSIONS

Racially, ethnically, and socioeconomically diverse patients with sleep disorders perceived a wearable as useful and acceptable for sleep health. Participants also uncovered external barriers related to the perceived usefulness of the technology, such as housing status, insurance coverage, and clinical support. Future studies should further examine how to best address these barriers so that wearables, such as the SomnoRing®, can be successfully implemented in the safety-net health setting.

CLINICALTRIAL

This manuscript does not report on a clinical trial.

The association of stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults

OBJECTIVE

To examine associations between stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults.

DESIGN

A cross-sectional analysis of the National Health Interview Survey.

PARTICIPANTS

Black adults (N = 16,315) with a mean age of 40 ± 0.1 years, mostly women (52.7%), college graduates (40.7%), and U.S.-born (82.5%).

MEASUREMENTS

Participants self-reported sleep duration, insomnia symptoms, frequent stress (yes/no), and work hours in the prior week (1-39 hours, 40 hours, ≥41 hours). Poisson regression with robust variance was used to test associations overall and by nativity.

RESULTS

Working ≥41 hours, frequent stress, and short sleep duration (<7 hours) were reported by 22%, 24.9%, and 43% of participants, respectively. U.S.-born and Foreign-born Black adults who reported frequent stress and working ≥41 hours vs. 40 hours had 60% and 19% higher prevalence of short sleep duration (adjusted prevalence ratio [aPR] = 1.60, 95% confidence interval [CI]: 1.47, 1.74 and aPR = 1.19, 95% CI: 1.12, 1.25, respectively). Foreign-born Black adults who worked 1-39 hours vs. 40 hours, had higher prevalence of short sleep duration, aPR = 1.18, 95% CI: 1.01, 1.37. U.S.-born Black adults who worked ≥41 hours vs. 40 hours had higher prevalence of insomnia symptoms (trouble falling asleep: aPR = 1.33 [95% CI: 1.13, 1.56], trouble staying asleep: aPR = 1.33 [95% CI: 1.16, 1.53]).

CONCLUSION

Frequent stress and working ≥41 hours are likely salient determinants of sleep health for U.S. and Foreign-born Black individuals. Further, less work hours (Foreign-born) while longer work hours (U.S.-born) were associated with short sleep duration. Stress and work hours may be factors for sleep health interventions among Black adults.

Understanding the determinants of circadian health disparities and cardiovascular disease

Emerging research suggests that sleep contributes to racial disparities in cardiovascular disease (CVD). Racial/ethnic minorities are disproportionately affected by poor cardiovascular outcomes including obesity, hypertension and diabetes. Although circadian rhythms affect sleep patterns, few studies have examined disparities in circadian health or the contribution of circadian disparities to CVD. In this paper, we provide an overview of the relation between circadian health and CVD in the context of health disparities. We discuss (1) the current knowledge on racial disparities in circadian health; (2) social and environmental determinants of circadian health disparities; (3) the cardiovascular consequences of circadian disparities; and (4) future opportunities to advance the field of circadian disparities. In brief, our findings demonstrated that among a small literature, racial minorities (mainly African American) were more likely to have a shorter circadian period, delayed phase shifts, and were more likely to be shift workers, which are associated with CVD risk factors. Given racial minorities are disproportionately affected by CVD and CVD risk factors, it is important to further understand circadian health as an intervention target and support more research among racial minorities to understand circadian health in these populations.

The role of sleep in health and health inequities in early childhood in Aotearoa New Zealand

This research investigated associations between multiple aspects of sleep health and child health, and the role of sleep in ethnic health inequities in early childhood. Questionnaire data on sleep and health of 3-year-old children (340 Māori, 570 non-Māori) in the Moe Kura: Mother and Child, Sleep and Wellbeing in Aotearoa/New Zealand study were analysed cross-sectionally. Logistic regression models investigated associations between poor sleep and health; and the contribution of socioeconomic deprivation, racism, and poor sleep to ethnic inequities in health (socioemotional difficulties; overweight/obesity; and asthma/eczema/allergy). Sleep measures included weekday and weekend sleep duration (per 24h), differences between weekday and weekend sleep duration and sleep timing, and sleep disturbance. Multiple aspects of sleep were associated with socioemotional or physical health outcomes. Ethnic health inequities existed, with Māori children having higher odds of poor health for all health measures. In sequential logistic regression models, socioeconomic deprivation attenuated ethnic health inequities, as did further adjustment for racism, and for sleep. Findings indicate that poor sleep health may be a pathway linking social disadvantage to ethnic inequities in health outcomes in early childhood. Results provide support for tackling systemic drivers of racism, and social and sleep inequities, to achieve health equity in early childhood.

Disparities in sleep duration among American children: effects of race and ethnicity, income, age, and sex

Children in the United States sleep less than the recommended amount and sleep deficiencies may be worse among disadvantaged children. Prior studies that compared sleep time in children of different race/ethnic groups mostly relied on questionnaires or were limited to small sample sizes. Our study takes advantage of the Adolescent Brain Cognitive Development study to compare total sleep time using a week of actigraphy data among American children (n = 4,207, 9 to 13 y old) of different racial/ethnic and income groups. We also assessed the effects of neighborhood deprivation, experience of discrimination, parent's age at child's birth, body mass index (BMI), and time the child fell asleep on sleep times. Daily total sleep time for the sample was 7.45 h and race/ethnicity, income, sex, age, BMI, were all significant predictors of total sleep time. Black children slept less than White children (∼34 min; Cohen's d = 0.95), children from lower income families slept less than those from higher incomes (∼16 min; Cohen's d = 0.44), boys slept less than girls (∼7 min; Cohen's d = 0.18), and older children slept less than younger ones (∼32 min; Cohen's d = 0.91); mostly due to later sleep times. Children with higher BMI also had shorter sleep times. Neither area deprivation index, experience of discrimination, or parent's age at child's birth significantly contributed to sleep time. Our findings indicate that children in the United States sleep significantly less than the recommended amount for healthy development and identifies significant racial and income disparities. Interventions to improve sleep hygiene in children will help improve health and ameliorate racial disparities in health outcomes.

The Need for Social and Environmental Determinants of Health Research to Understand and Intervene on Racial/Ethnic Disparities in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), a sleep-disordered breathing (SDB) disorder, affects at least 25 million adults in the United States and is associated with increased risk for hypertension, diabetes, and cardiovascular disease (CVD). Racial/ethnic minorities have a disproportionate burden of OSA along with the health sequelae associated with this condition. Despite supporting evidence of racial/ethnic disparities, few studies have investigated SDB including OSA among minoritized racial/ethnic groups. In this scoping review of the literature, the authors summarize current findings related to racial/ethnic disparities in OSA, identified social and environmental determinants of health, treatment inequities, and promising evidence-based interventions and conclude with future research directions.

Meeting Specific 24-Hour Movement Guidelines Is Associated With BMI Among University Students With Overweight/Obesity

Background: Approximately 40% of college/university students have overweight/obesity; physical activity and sleep play a role. To address these interrelated behaviors, Canada recently released 24-Hour Movement Guidelines. This study aimed to determine (1) the percent of students with overweight/obesity meeting Canadian 24-Hour Movement Guidelines, (2) whether health behaviors differ by demographics, and (3) whether meeting guidelines is associated with BMI. Methods: University students 18–35 years (n = 459) enrolled in a randomized controlled weight management trial completed 1 week of ActiGraph measured activity, self-reported sleep duration, researcher-measured height/weight, and demographics at baseline. ANOVA and t-tests determined differences in student demographics and BMI among those meeting vs not meeting each guideline. Results: Of the analytic sample (n = 403), 341 (84.6%) met the MVPA guideline, 284 (70.5%) met the LIPA guideline, 236 (58.6%) met the sleep guideline, 62 (15.4%) met the sedentary time guideline, and 34 (8.4%) met all guidelines. Students meeting MVPA (30.8±4.3 vs 32.5±4.5, P = .008) or sleep (30.7±4.4 vs 31.6±4.3, P = .04) guidelines had significantly lower BMIs compared to those not meeting each guideline. Percent of students meeting sleep ( P = .039) or all guidelines ( P = .012) differed by race/ethnicity. Conclusion: Meeting MVPA/sleep guidelines is associated with lower BMI; these behaviors are important targets for future weight management programs.

Mediating role of psychological distress in the associations between neighborhood social environments and sleep health

STUDY OBJECTIVES

The characteristics of neighborhood social environments, such as safety and social cohesion, have been examined as determinants of poor sleep. The current study investigates associations between neighborhood social characteristics and sleep health, as well as the mediating role of psychological distress on these possible associations.

METHODS

Three waves of PHRESH Zzz (n = 2699), a longitudinal study conducted in two low-income, predominately Black neighborhoods, were utilized for this analysis. The characteristics of neighborhood social environments were measured using crime rates, a neighborhood social disorder index, and self-reported social cohesion. Sleep health was measured via 7 days of wrist-worn actigraphy as insufficient sleep, sleep duration, wake after sleep onset (WASO), and sleep efficiency. G-estimations based on structural nested mean models and mediation analyses were performed to estimate the effects of neighborhood social environments on sleep as well as direct/indirect effects through psychological distress.

RESULTS

Crime rate around residential addresses was associated with increased risk of insufficient sleep (risk ratio: 1.05 [1.02, 1.12]), increased WASO (β: 3.73 [0.26, 6.04]), and decreased sleep efficiency (β: -0.54 [-0.91, -0.09]). Perceived social cohesion was associated with decreased risk of insufficient sleep (OR: 0.93 [0.88, 0.97]). Psychological distress mediated part of the associations of crime and social cohesion with insufficient sleep.

CONCLUSIONS

Neighborhood social environments may contribute to poor sleep health in low-income, predominantly Black neighborhoods, and psychological distress can be a salient pathway linking these neighborhood characteristics and sleep health.

A primer on sleep for MFTs: Implications and practical considerations

Despite many marriage and family therapists (MFTs) utilizing the Biopsychosocial-Spiritual (BPSS) framework in assessment and treatment, there is still a lack of education on sleep and the implications for mental, emotional, and relational health. Newer research within many fields highlights the far-reaching spillover effects of short or poor-quality sleep that can affect our clients. MFTs need to know how to assess, how to provide proper psychoeducation, how to apply this knowledge in clinical settings, and how to collaborate with other healthcare providers. As such, the purpose of this article is threefold: (a) review the biopsychosocial-spiritual importance of sleep; (b) equip MFTs with information on sleep assessment, how to identify situations for referral, and how to provide psychoeducation on sleep hygiene; and (c) review important considerations for research and practice for MFTs.

Acculturation Stress, Age at Immigration, and Employment Status as Predictors of Sleep Among Latinx Immigrants

Sleep is important for physical and mental health. Latinx individuals are thought to experience worse sleep and associated health outcomes, resulting in health disparities. There is a dearth of research on the factors (e.g., employment status, age at immigration) that predict poor sleep among Latinx immigrants. The present study aimed to (1) examine the link between demographic factors, immigration-related factors, and acculturation stress, and sleep, and (2) identify factors that either attenuate or intensify the link between acculturation stress and sleep among Latinx immigrants in the US South, an immigrant-hostile area that is home to an increasing Latinx population that remains understudied. Hierarchical regressions were used to analyze data from 391 Latinx adult immigrants, examining the link between demographic factors, immigration-related factors, acculturation stress, and two sleep variables (sleep quality, difficulty falling asleep). Employment status and age at immigration were examined as moderators of the link between acculturation stress and sleep. Data were collected through in-person surveys. Regressions showed that acculturation stress was significantly linked to worse sleep quality (β = 0.30, p = 0.001) and more difficulty falling asleep (β = 0.41, p < 0.001), while controlling for participant characteristics. Younger age at immigration (β = - 0.14, p = 0.005) and being unemployed (β = - 0.13, p = 0.006) were associated with more difficulty falling asleep. Age at immigration intensified the relationship between acculturation stress and sleep quality (β = 0.14, p = 0.005), difficulty falling asleep (β = 0.15, p = 0.002). Reducing acculturation stress is a meaningful intervention focus, with important implications for sleep health, particularly for recent Latinx immigrants. Age at immigration and employment status are also important factors to consider when designing targeted interventions.

Links Between Socioeconomic Status, Daily Depressive Affect, Diurnal Cortisol Patterns, and All-Cause Mortality

OBJECTIVE

Socioeconomic status (SES) remains a robust risk factor for mortality. Various theoretical models postulate that lower SES is associated with higher negative affect, which then initiates a cascade of physiological disturbances that contribute to illness and early mortality. However, few studies have explicitly investigated the interplay between psychological and biological factors in determining SES disparities in mortality. This study examined the role of daily negative affect and cortisol secretion in explaining the SES-mortality link in a large sample of US adults.

METHODS

Using data from the Midlife in the United States study (n = 1735, mean [standard deviation] age = 56.40 [12.10] years, 56.4% female), we tested longitudinal associations between SES, daily negative affect, daily cortisol levels, and all-cause mortality 13 years later. Daily negative affect was classified into three clusters reflecting depressive affect, anxiety, and anger.

RESULTS

Higher SES was linked to a lower risk of all-cause mortality (hazard ratio = 0.94, 95% confidence interval = 0.90 to 0.97). Furthermore, there was a sequential link between higher SES and lower mortality through lower daily depressive affect and a steeper ("healthier") diurnal cortisol slope (indirect effect = -0.0007, 95% confidence interval = -0.0014 to -0.0002). Daily anxiety and anger were not associated with cortisol levels or mortality (p values > .05).

CONCLUSIONS

These findings suggest that daily negative emotional experiences and the hypothalamic-pituitary-adrenal axis functioning may constitute important psychological and physiological pathways underlying the link between SES and all-cause mortality.

Differential influences of dietary sodium on blood pressure regulation based on race and sex

There are clear differences between men and women, and differences among races, in the incidence and prevalence of hypertension. Furthermore, there is extensive inter-individual variability among humans in the extent to which sodium ingestion alters blood pressure. Orthostatic intolerance and orthostatic hypotension are more common in women; these are often treated with a high salt diet, which has variable efficacy in increasing blood volume and blood pressure. Conversely, people with certain forms of hypertension are often counseled to decrease their sodium intake. Non-Hispanic Black men and women have higher rates of hypertension compared to non-Hispanic White men and women and other racial/ethnic groups. In aggregate, Black women appear to have better orthostatic tolerance than White women. In the present paper, we summarize and evaluate the current evidence for mechanisms of blood pressure regulation in men and women, as well as differences between Black and White groups, with a focus on cardiovascular responses to salt and differences among these groups. We also provide a brief review of factors that are not traditionally considered to be "biological" - such as socio-economic disparities resulting from historic and contemporary inequity across racial groups. These non-biological factors have direct and substantial influences on cardiovascular mechanisms, as well as implications for the influences of salt and sodium intake on blood pressure and cardiovascular health. We conclude that both biological and socio-economic factors provide critical modulating influences when considering the impacts of sodium on cardiovascular health as functions of race and sex.

Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis

BACKGROUND

Currently, there is no consensus on the effect of sleep deprivation on male serum testosterone. This systematic review and meta-analysis aimed to determine the association between partial/total sleep deprivation and male serum testosterone level.

METHODS

The literature related to sleep deprivation and male serum testosterone in the PubMed, Embase, and Cochrane Library databases were searched from their inception to July 15, 2021. Data were pooled using the Stata 15 software. The results were presented as standard mean differences (SMDs) with their 95% confidence intervals (CIs).

RESULTS

Eighteen studies involving 252 men were included in the systematic review and meta-analysis. The findings revealed that short-term partial sleep deprivation had no significant effect on male serum testosterone (SMD = -0.22; 95% CI: -0.5, 0.06; P = 0.13), while total sleep deprivation reduced the male testosterone levels (SMD = -0.64; 95% CI: -0.87, -0.42; P < 0.001). According to the intervention duration of total sleep deprivation, subgroup analysis was conducted by a fixed-effects model. The results revealed that the serum testosterone was significantly decreased after 24 h total sleep deprivation (SMD = - 0.67; 95% CI = - 0.93, -0.42, P < 0.001), as well as 40-48 h total sleep deprivation (SMD = - 0.74; 95% CI = - 1.22, -0.26, P = 0.002).

CONCLUSIONS

This meta-analysis revealed that total sleep deprivation (more than or equal to 24 h) reduces the male testosterone levels, while short-term partial sleep deprivation has no significant effect on male serum testosterone. Sleep duration plays a pivotal role in maintaining male serum testosterone levels.

Race and Ethnicity and Cardiometabolic Risk Profile: Disparities Across Income and Health Insurance in a National Sample of US Adults

CONTEXT

Income and health insurance are important social determinants of cardiovascular disease (CVD) and may explain much racial/ethnic variation in CVD burden. However, racial/ethnic disparities in cumulative cardiometabolic (CMB) risk profile by insurance type and income level have not been studied on a national scale.

OBJECTIVES

To test the hypothesis that racial/ethnic minorities experience greater CMB burden at each income level and insurance type than non-Hispanic Whites (NHW).

SETTING

This study used nationally representative data from the National Health Interview Survey (NHIS).

DESIGN

Observational (cross-sectional).

PARTICIPANTS

In total, 134661 (weighted N = 197780611) adults, 18 years or older, from the 2013-2017 NHIS.

PRIMARY OUTCOME

CMB risk profile.

INTERVENTION/ANALYSIS

Age-adjusted prevalence of optimal, average, and poor CMB risk profile-defined respectively as self-report of 0, 1-2, and 3 or more risk factors of diabetes, hypertension, obesity, or hypercholesterolemia-was examined for NHW, non-Hispanic Blacks (NHB), and Hispanics. Multivariable ordinal logistic regression models were used to test the association between race and ethnicity and CMB profile overall and separately by household income level and insurance type.

RESULTS

Overall, 15% of NHB and 11% of Hispanics experienced poor CMB risk profile, compared with 9% for NHW. In fully adjusted models, NHB and Hispanics, respectively had nearly 25%-90% and 10%-30% increased odds of poor CMB profile across insurance types and 45%-60% and 15%-30% increased odds of poor CMB profile across income levels, relative to NHW. The observed disparities were widest for the Medicare group (NHB: OR = 1.90; Hispanics: OR = 1.31) and highest-income level (NHB: OR = 1.62).

CONCLUSIONS

Racial/ethnic minorities experience poor CMB profile at each level of income and insurance. These findings point to the need for greater investigation of unmeasured determinants of minority cardiovascular (CV) health, including structural racism and implicit bias in CV care.

Perceived home sleep environment: associations of household-level factors and in-bed behaviors with actigraphy-based sleep duration and continuity in the Jackson Heart Sleep Study

STUDY OBJECTIVES

In an older African-American sample (n = 231) we tested associations of the household environment and in-bed behaviors with sleep duration, efficiency, and wakefulness after sleep onset (WASO).

METHODS

Older adult participants completed a household-level sleep environment questionnaire, a sleep questionnaire, and underwent 7-day wrist actigraphy for objective measures of sleep. Perceived household environment (self-reported) was evaluated using questions regarding safety, physical comfort, temperature, noise, and light disturbances. In-bed behaviors included watching television, listening to radio/music, use of computer/tablet/phone, playing video games, reading books, and eating. To estimate the combined effect of the components in each domain (perceived household environment and in-bed behaviors), we calculated and standardized a weighted score per sleep outcome (e.g. duration, efficiency, WASO), with a higher score indicating worse conditions. The weights were derived from the coefficients of each component estimated from linear regression models predicting each sleep outcome while adjusting for covariates.

RESULTS

A standard deviation increase in an adverse household environment score was associated with lower self-reported sleep duration (β = -13.9 min, 95% confidence interval: -26.1, -1.7) and actigraphy-based sleep efficiency (β = -0.7%, -1.4, 0.0). A standard deviation increase in the in-bed behaviors score was associated with lower actigraphy-based sleep duration (β = -9.7 min, -18.0, -1.3), sleep efficiency (β = -1.2%, -1.9, -0.6), and higher WASO (5.3 min, 2.1, 8.6).

CONCLUSION

Intervening on the sleep environment, including healthy sleep practices, may improve sleep duration and continuity among African-Americans.

A prospective study of multiple sleep dimensions and hypertension risk among white, black and Hispanic/Latina women: findings from the Sister Study

BACKGROUND

Poor sleep is associated with increased hypertension risk, but few studies have evaluated multiple sleep dimensions or investigated racial/ethnic disparities in this association among women.

METHOD

We investigated multiple sleep dimensions (sleep duration, inconsistent weekly sleep patterns, sleep debt, frequent napping and difficulty falling or staying asleep) and hypertension risk among women, and determined modification by age, race/ethnicity and menopausal status. We used data from the Sister Study, a national cohort of 50 884 women who had sisters diagnosed with breast cancer in the United States enrolled in 2003-2009 and followed through September 2018.

RESULTS

Of 33 497 women without diagnosed hypertension at baseline (mean age ± standard deviation: 53.9 ± 8.8 years; 88.7% White, 6.4% Black and 4.9% Hispanic/Latina), 23% (n = 7686) developed hypertension over a median follow-up of 10.1 years [interquartile range: 8.2-11.9 years]. Very short, short or long sleep duration, inconsistent weekly sleep patterns, sleep debt, frequent napping, insomnia, insomnia symptoms as well as short sleep and exploratory cumulative poor sleep score were associated with incident hypertension after adjustment for demographics factors. After additional adjustment for lifestyle and clinical factors, insomnia [hazard ratio = 1.09, 95% confidence interval (95% CI): 1.03-1.15] and insomnia symptoms plus short sleep (hazard ratio = 1.13, 95% CI: 1.05-1.21) remained associated with incident hypertension. These associations were stronger in younger (age<54 vs. ≥54 years) and premenopausal vs. postmenopausal women (all P-interaction < 0.05). Associations did not differ by race/ethnicity (all P-interaction > 0.05).

CONCLUSION

Thus, screening for multiple sleep dimensions and prioritizing younger and premenopausal women may help identify individuals at high risk for hypertension.

Racial-ethnic Differences in Actigraphy, Questionnaire, and Polysomnography Indicators of Healthy Sleep: The Multi-Ethnic Study of Atherosclerosis

A paradigm shift in sleep science argues for a systematic, multidimensional approach to investigate sleep's association with disease and mortality and to address sleep disparities. We utilized the comprehensive sleep assessment of the Multi-Ethnic Study of Atherosclerosis (2010- 2013), a cohort of U.S. White, Black, Chinese, and Hispanic adults and older adults (n=1,736; mean age=68.3), to draw 13 sleep dimensions and create composite Sleep Health Scores to quantify multidimensional sleep health disparities. After age and sex adjustment in linear regression, compared to White participants, Black participants showed the greatest global sleep disparity, then Hispanic and Chinese participants. We estimated relative 'risk' of obtaining favorable sleep compared to White adults at the component level by race/ethnicity (lower is worse). The largest disparities were in objectively-measured sleep timing regularity (RRBlack [95% CI]: 0.37 [0.29,0.47], RRHispanic: 0.64 [0.52,0.78], RRChinese: 0.70 [0.54,0.90]) and duration regularity (RRBlack: 0.55 [0.47,0.65], RRHispanic: 0.76 [0.66,0.88], RRChinese: 0.74 [0.61,0.90]), after sex and age adjustment. Disparities in duration and continuity were also apparent, and Black adults were additionally disadvantaged in %N3 (slow wave sleep), sleepiness, and sleep timing (24-hour placement). Sleep timing regularity, duration regularity, duration, and continuity may comprise a multidimensional cluster of targets to reduce racial-ethnic sleep disparities.

Sleep fragmentation and the risk of obesity: The Sleep Heart Health Study

OBJECTIVE

Sleep disturbances have been recognized as a risk factor for obesity. This study used polysomnography records to investigate associations between sleep fragmentation and obesity.

METHODS

Objectively measured sleep fragmentation data recorded by in-home polysomnography, including total arousal index (ArI-total), ArI in rapid eye movement (REM) sleep (ArI-REM), ArI in non-REM sleep (ArI-NREM), sleep fragmentation index, sleep efficiency (SE), and wake after sleep onset (WASO), were based on the Sleep Heart Health Study (2,835 men and 2,888 women with a mean [SD] age of 63.2 [11.2] years). Multivariable regression analyses were used to examine the relationship between sleep fragmentation and obesity.

RESULTS

Multinomial logistic regression showed that participants with obesity have a significantly higher ArI-total (odds ratio [OR] 1.018; 95% CI: 1.010-1.026, p < 0.001), ArI-REM (OR 1.010; 95% CI: 1.002-1.018, p = 0.009), ArI-NREM (OR 1.017; 95% CI: 1.009-1.024, p < 0.001), and WASO (OR 1.003; 95% CI: 1.001-1.005, p = 0.007) compared with those with normal weight. Furthermore, multiple linear regression analyses showed an obvious correlation between ArI-total, ArI-REM, ArI-NREM, SE, WASO, and BMI.

CONCLUSIONS

The results revealed that ArI-total, ArI-REM, ArI-NREM, SE, and WASO were associated with obesity. The improvement of sleep fragmentation may contribute to decreasing the risk of obesity.

A scoping review of racial/ethnic disparities in sleep

BACKGROUND

Despite remarkable achievements in ensuring health equity, racial/ethnic disparities in sleep still persist and are emerging as a major area of concern. Accumulating evidence has not yet been well characterized from a broad perspective. We conducted a scoping review of studies on sleep disparities by race/ethnicity to summarize characteristics of existing studies and identify evidence gaps.

METHODS

We searched PubMed, CINAHL, PsycINFO, and Web of Science databases for studies of racial/ethnic disparities in sleep. Studies that met inclusion criteria were retrieved and organized in a data charting form by study design, sleep measuring methods, sleep features, and racial/ethnic comparisons.

RESULTS

One hundred sixteen studies were included in this review. Most studies focused on disparities between Whites and Blacks. Disproportionately fewer studies examined disparities for Hispanic, Asian, and other racial/ethnic groups. Self-reported sleep was most frequently used. Sleep duration, overall sleep quality, and sleep disordered breathing were frequently studied, whereas other features including sleep efficiency, latency, continuity, and architecture were understudied, particularly in racial minority groups in the US. Current study findings on racial/ethnic disparities in most of sleep features is mixed and inconclusive.

CONCLUSIONS

This review identified significant evidence gaps in racial/ethnic disparities research on sleep. Our results suggest a need for more studies examining diverse sleep features using standardized and robust measuring methods for more valid comparisons of sleep health in diverse race/ethnicity groups.

An exploration of clinical, behavioral, and community factors associated with sleep duration and efficiency among middle-aged Black/African American smokers

STUDY OBJECTIVES

We examined the most important correlates to sleep duration and efficiency from a comprehensive array of multilevel factors.

METHODS

Baseline data from a cohort of 216 Black/African American smokers aged 40-65 years were examined. The binary outcomes of healthy sleep duration (6-8 h/night) and efficiency (≥85%) were ascertained from 14 consecutive days of actigraphy. Seventy-three independent variables from socio-demographic, individual behavioral, individual physiological, interpersonal, and community domains were assessed. Random survival forest decision trees were generated for each outcome, and variable importance metrics used to rank the predictive abilities of exposure variables. The 5 most predictive exposure variables for each outcome were entered into a regression model of the respective outcome (with age and sex).

RESULTS

Study participants (N = 216) had a mean age of 54.57 years (SD = 6.17) and 57% were male. Healthy sleep duration was achieved by 56.5% and healthy sleep efficiency by 13.6% of the sample. Regression models showed every additional minute of light physical activity was associated with 1% increased odds, while every unit decrease in the inflammation marker of interleukin-8 was associated with 12% increased odds, of achieving a healthy sleep duration. Every unit increase in total social support was associated with a 34% increased odds, while every unit increase in the hazardous drinking score corresponded with 30% decreased odds, of achieving healthy sleep efficiency.

CONCLUSIONS

Light physical activity, social support, and alcohol consumption may be key modifiable intervention targets to improving sleep duration and sleep efficiency in this population.

Racial disparities in sleep health between Black and White young adults: The role of neighborhood safety in childhood

OBJECTIVES

Black adults in the United States have shorter sleep durations and poorer sleep efficiency relative to White adults, yet reasons for these disparities are not well explicated. The objective of this study was to examine neighborhood safety in childhood as a mediator of subsequent racial disparities in sleep.

METHODS

Data were from Black and White young adults attending a large, predominantly White university in the Southeastern United States (N = 263; 52% Black, 53% female; Mean age = 19.21 years, SD = 1.01). Sleep parameters were assessed from eight nights of wrist actigraphy (time in bed, sleep duration, and efficiency) and an established self-report measure of daytime sleepiness. Residential histories from birth through age 18 were documented, and retrospective self-reports of neighborhood safety in childhood were assessed.

RESULTS

Black participants had less time in bed (p < 0.001), shorter sleep duration (p < 0.001), poorer sleep efficiency (p < 0.001), and more daytime sleepiness (p = 0.009) than White participants. Neighborhood safety mediated race differences in time in bed (p = 0.028), sleep duration (p = 0.033), and daytime sleepiness (p = 0.048), but not sleep efficiency. Findings were substantively unchanged after adjustment for family socioeconomic status, BMI, and substance use.

CONCLUSIONS

Findings support the hypothesis that neighborhood safety in childhood may partially account for race differences in subsequent sleep duration and daytime sleepiness. Addressing racial inequities in childhood neighborhood safety may be an important step toward reducing racial disparities in sleep health.

A Model of Adolescent Sleep Health and Risk for Type 2 Diabetes

PURPOSE OF REVIEW

This paper presents a review of the current literature in support of a model explaining the relationships between sleep health and risk for type 2 diabetes in adolescents.

RECENT FINDINGS

Short sleep duration is associated with risk of developing obesity in youth. Sleep restriction increases energy expenditure, but also increases hunger, appetite, and food intake, causing positive energy balance, impacting appetite-regulating hormones, and leading to increased eating late at night. Insufficient sleep may lead to reduced physical activity and greater sedentary behaviors. In addition, short sleep duration is associated with reduced insulin sensitivity. The cumulative negative consequences of insufficient sleep increase risk for type 2 diabetes. Applications to clinical care, public policy, and future research are discussed. Insufficient sleep in adolescence increases risk for type 2 diabetes directly through impact on insulin sensitivity and indirectly through increased dietary intake, sedentary activity, and weight gain.

α-Adrenergic receptor blockade attenuates pressor response during mental stress in young black adults

Black individuals exhibit increased blood pressure (BP) responses to sympathetic stimulation that are associated with an increased risk of hypertension (HTN). We tested the hypothesis that α1 -adrenergic blockade inhibits the increased BP response during and after 45-min stress in young normotensive Black adults, which may be mediated, in part, by dampened vasoconstriction and decreased renal sodium retention. Utilizing a double-masked randomized, crossover study design, 51 normotensive Black adults (31 ± 8 yr) were treated with either a placebo or 1 mg/day of prazosin for 1 week. On the final day of each treatment, hemodynamic measures and urinary sodium excretion (UNaV) were collected before (Rest), during (Stress) and after (Recovery) 45 min of mental stress induced via a competitive video game task. During the Stress period, diastolic BP and total peripheral resistance (TPR) were significantly lower with prazosin compared to placebo (p < .05 for both). Similarly, we observed lower systolic BP, diastolic BP, and TPR during the Recovery period with prazosin versus placebo (p < .05 for both). There was no effect of prazosin on stress-associated UNaV. The change in systolic BP from Rest to Recovery was positively associated with the change in TPR with both treatments (p < .05 for both). In summary, prazosin treatment dampened BP reactivity to 45-min mental stress and lowered post-stress BP over the recovery period, which was linked to reduce TPR in young normotensive Black adults. These results suggest that α1 -adrenergic receptor activity may contribute to BP responses and delayed BP recovery to prolonged mental stress through increased vasoconstriction in Black adults.

Violent crime, police presence and poor sleep in two low-income urban predominantly Black American neighbourhoods

OBJECTIVE

To examine violent crime in relation to sleep and explore pathways, including psychological distress, safety perceptions and perceived police presence, that may account for associations.

METHODS

In 2018, 515 predominantly Black American (94%) adults (Pittsburgh, Pennsylvania, USA) provided survey data: actigraphy-assessed sleep duration and wakefulness after sleep onset (WASO). We estimated pathways from violent crime (2016-2018) to sleep through psychological distress, perceptions of safety and perceived adequacy of police presence.

RESULTS

WASO was most strongly associated with violent crimes that were within 1/10 mile of the participant's home and within the month preceding the interview. Violent crimes were associated with lower perceived safety (β=-0.13 (0.03), p<0.001) and greater WASO (β=5.96 (2.80), p=0.03). We observed no indirect associations between crime and either WASO or sleep duration through any of the tested mediators. Crime was not associated with sleep duration.

CONCLUSIONS

We demonstrated that more proximal and more recent violent crimes were associated with reduced perceived safety and worse WASO. Differential exposure to violent crime among Black Americans may contribute to health disparities by reducing residents' perceived safety and sleep health.

Experimental sleep loss, racial bias, and the decision criterion to shoot in the Police Officer's Dilemma task

Violent behavior, police brutality, and racial discrimination are currently at the forefront of society’s attention, and they should be. We investigated whether mild sleep loss—as typical for many adults throughout the work week—could aggravate the socio-emotional-cognitive processes contributing to violence and discrimination. In a sample of 40 healthy young adults, we either experimentally restricted participants’ sleep for four nights (6.2 h/night) or let participants obtain normal sleep (7.7 h/night)—and then had them complete the Police Officer’s Dilemma Task. In this computerized task, the participant must rapidly decide to shoot or not shoot at White and Black men who either are or are not holding a gun. Results showed significant racial biases, including more and quicker shooting of Black targets compared to White targets. Furthermore, signal detection analyses demonstrated that mild sleep restriction changed participants’ decision criterion, increasing the tendency to shoot, even when controlling for psychomotor vigilance, fluid intelligence, and self-reported desirability to behave in a socially acceptable manner. The increased tendency to shoot was also observed in participants who reported believing that they had adapted to the sleep loss. Future experimental research using trained police officers will help establish the generalizability of these laboratory effects. Importantly, sleep loss is modifiable via organization-level changes (e.g., shift scheduling, light entrainment) and individual-level interventions (e.g., sleep hygiene education, incentives for behavioral change), suggesting that if sleep loss is corrected, it could save lives—including Black lives.

Associations between self-reported sleep duration and cardiometabolic risk factors in young African-origin adults from the five-country modeling the epidemiologic transition study (METS)

OBJECTIVES

To investigate associations between self-reported sleep duration and cardiometabolic (CM) risk factors in African-origin adults residing in five countries spanning the epidemiologic transition.

DESIGN

Cross-sectional.

SETTING AND PARTICIPANTS

Ghanaian (n = 491), South African (n = 503), Jamaican (n = 508), Seychellois (n = 501) and American (n = 480) men and women.

MEASUREMENTS

Self-reported sleep duration was obtained using questionnaires. Sex- and site-stratified logistic regression analyses investigated relationships between sleep duration, individual CM risk factors and a binary CM risk variable (presence of ≥3 CM risk factors), adjusting for age, physical activity and education.

RESULTS

Sleep duration distributions varied by cohort: 44.5%, 41.4%, 35.9%, 16.8% and 2.5% of American, Jamaican, Seychellois, Ghanaian and South African men reported <7 h sleep per night respectively (p < 0.001). Similarly, 42.6%, 28.6%, 25.2%, 12.8% and 1.5% of American, Jamaican, Seychellois, Ghanaian and South African women reported <7 h sleep respectively (p < 0.001). American men reporting ≤6 h sleep were more likely to be in the elevated CM risk group (OR: 2.52, 95%CI: 1.02, 6.22, p = 0.045) and to have a high waist circumference (OR: 2.44, 95%CI: 1.07, 5.57, p = 0.034) compared to those reporting 8 h sleep. Jamaican women reporting ≤6 h sleep (OR: 2.53, 95%CI: 1.19, 5.36, p = 0.016) and American women reporting 7 h sleep (OR: 2.71, 95%CI: 1.17, 6.26, p = 0.002) were more likely to be obese than those reporting 8 h sleep.

CONCLUSIONS

Associations between short sleep and CM risk factors were only evident in the American men and women and Jamaican women. Future interventions to address CM risk and sleep health may need to be country-specific when targeting high-risk populations.

Sleep Health: An Opportunity for Public Health to Address Health Equity

The concept of sleep health provides a positive holistic framing of multiple sleep characteristics, including sleep duration, continuity, timing, alertness, and satisfaction. Sleep health promotion is an underrecognized public health opportunity with implications for a wide range of critical health outcomes, including cardiovascular disease, obesity, mental health, and neurodegenerative disease. Using a socioecological framework, we describe interacting domains of individual, social, and contextual influences on sleep health. To the extent that these determinants of sleep health are modifiable, sleep and public health researchers may benefit from taking a multilevel approach for addressing disparities in sleep health. For example, in addition to providing individual-level sleep behavioral recommendations, health promotion interventions need to occur at multiple contextual levels (e.g., family, schools, workplaces, media, and policy). Because sleep health, a key indicator of overall health, is unevenly distributed across the population, we consider improving sleep health a necessary step toward achieving health equity.

Sleep and HbA1c in Patients With Type 2 Diabetes: Which Sleep Characteristics Matter Most?

OBJECTIVE

Poor sleep has been identified as a risk factor for poor glycemic control in individuals with type 2 diabetes (T2D). As optimal sleep can be characterized in several ways, we evaluated which sleep characteristics are most strongly associated with glycated hemoglobin A_1c (HbA_1c).

RESEARCH DESIGN AND METHODS

A total of 172 patients with T2D completed 7-day wrist-actigraphy and sleep questionnaires. Linear regression was used to evaluate associations between sleep measures (total sleep duration, variability in sleep duration, midsleep time, variability in midsleep time, sleep efficiency, subjective sleep quality, and subjective insomnia symptoms) and HbA_1c, individually and in concert.

RESULTS

Variability in sleep duration was individually most strongly associated with HbA_1c (β = 0.239; P = 0.002; R ² = 4.9%), followed by total sleep duration (U-shaped: β = 1.161/β² = 1.044; P = 0.017/0.032; R ² = 4.3%), subjective sleep quality (β = 0.191; P = 0.012; R ² = 3.6%), variability in midsleep time (β = 0.184; P = 0.016; R ² = 3.4%), and sleep efficiency (β = -0.150; R ² = 2.3%). Midsleep time and subjective insomnia symptoms were not associated with HbA_1c. In combination, variability in sleep duration, total sleep duration, and subjective sleep quality were significantly associated with HbA_1c, together explaining 10.3% of the variance in HbA_1c. Analyses adjusted for covariates provided similar results, although the strength of associations was generally decreased and showing total sleep duration and subjective sleep quality to be most strongly associated with HbA_1c, together explaining 6.0% of the variance in HbA_1c.

CONCLUSIONS

Sleep in general may be a modifiable factor of importance for patients with T2D. The prevention of sleep curtailment may serve as a primary focus in the sleep-centered management of T2D.