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

Bidirectional predictors between baseline and recovery sleep measures and cardiovascular measures during sleep deprivation and psychological stress

For the first time, we investigated bidirectional predictors between baseline and recovery sleep and cardiovascular (CV) measures during total sleep deprivation (TSD) and psychological stress in a five-day experiment with 32 healthy adults (27-53y; 14 females). CV measures were collected in the morning after two baseline nights (B1, B2) and during TSD morning (TSD AM) and evening following psychological stress (TSD PM). Actigraphy assessed sleep during B2 before TSD and the first recovery night (R1) after TSD. Higher B2 wake after sleep onset (WASO) predicted lower TSD PM stroke volume and higher TSD PM systemic vascular resistance index (SVRI), with greater B2 percent sleep predicting inverse relationships, explaining 12.8%-15.9% of the TSD CV variance. Also, higher B2 WASO predicted higher B2 AM SVRI. Furthermore, longer TSD left ventricular ejection time predicted later R1 sleep offset, longer sleep duration, and higher WASO; by contrast, higher TSD AM and TSD PM heart rate predicted earlier R1 sleep offset. TSD CV indices explained 14.8%-24.9% of the R1 sleep variance. Notably, females showed significant predictive bidirectional relationships. Our novel results demonstrate that baseline sleep predicts CV metrics during TSD and psychological stress, and that these metrics predict recovery sleep, underscoring crucial relationships, mechanisms, and biomarkers between sleep and cardiovascular health.

Racial and ethnic disparities in the perceived neighborhood walking environment and self-reported sleep health: A nationally representative sample of the United States

OBJECTIVES

To identify associations between perceived neighborhood walkability and sleep across racial and ethnic groups of US adults.

METHODS

Data from the 2020 National Health Interview Survey (N=27,521) were used to assess self-reported measures of walkability (pedestrian access, accessible amenities, unsafe walking conditions) and sleep (short and long duration; frequency of waking up unrested, trouble falling and staying asleep, sleep medication use). Stratified by racial and ethnic group, we calculated the age-adjusted prevalence of neighborhood walkability features and sleep measures and estimated prevalence ratios assessing associations between neighborhood walkability and sleep while adjusting for sociodemographic and health covariates.

RESULTS

The prevalence of unsafe walking conditions due to crime was lowest among non-Hispanic White adults (6.9%), and access to places to relax was lowest among non-Hispanic Black adults (72.5%). The prevalence of short sleep duration was highest among non-Hispanic Black adults (37.9%). Neighborhood environment features had differential associations with sleep when stratified by race and ethnicity. For example, walking path access was related to lower sleep medication use among non-Hispanic Asian adults (adjusted prevalence ratio (aPR): 0.42, 95% CI: 0.19-0.91) but greater use among non-Hispanic White adults (aPR: 1.24, 95% CI: 1.05-1.46). More associations were observed among non-Hispanic White adults than other groups; and the strongest magnitude of association was observed among non-Hispanic Asian adults (traffic and sleep medication aPR: 0.31, 95% CI: 0.12-0.84).

CONCLUSIONS

Associations between the neighborhood environment and sleep vary and may be inconsistent by race and ethnicity. Future research may help identify determinants.

Integrative Modeling of Accelerometry-Derived Sleep, Physical Activity, and Circadian Rhythm Domains With Current or Remitted Major Depression

Importance

Accelerometry has been increasingly used as an objective index of sleep, physical activity, and circadian rhythms in people with mood disorders. However, most prior research has focused on sleep or physical activity alone without consideration of the strong within- and cross-domain intercorrelations; and few studies have distinguished between trait and state profiles of accelerometry domains in major depressive disorder (MDD).

Objectives

To identify joint and individual components of the domains derived from accelerometry, including sleep, physical activity, and circadian rhythmicity using the Joint and Individual Variation Explained method (JIVE), a novel multimodal integrative dimension-reduction technique; and to examine associations between joint and individual components with current and remitted MDD.

Design, Setting, and Participants

This cross-sectional study examined data from the second wave of a population cohort study from Lausanne, Switzerland. Participants included 2317 adults (1164 without MDD, 185 with current MDD, and 968 with remitted MDD) with accelerometry for at least 7 days. Statistical analysis was conducted from January 2021 to June 2023.

Main Outcomes and Measures

Features derived from accelerometry for 14 days; current and remitted MDD. Logistic regression adjusted for age, sex, body mass index, and anxiety and substance use disorders.

Results

Among 2317 adults included in the study, 1261 (54.42%) were female, and mean (SD) age was 61.79 (9.97) years. JIVE reduced 28 accelerometry features to 3 joint and 6 individual components (1 sleep, 2 physical activity, 3 circadian rhythms). Joint components explained 58.5%, 79.5%, 54.5% of the total variation in sleep, physical activity, and circadian rhythm domains, respectively. Both current and remitted depression were associated with the first 2 joint components that were distinguished by the salience of high-intensity physical activity and amplitude of circadian rhythm and timing of both sleep and physical activity, respectively. MDD had significantly weaker circadian rhythmicity.

Conclusions and Relevance

Application of a novel multimodal dimension-reduction technique demonstrates the importance of joint influences of physical activity, circadian rhythms, and timing of both sleep and physical activity with MDD; dampened circadian rhythmicity may constitute a trait marker for MDD. This work illustrates the value of accelerometry as a potential biomarker for subtypes of depression and highlights the importance of consideration of the full 24-hour sleep-wake cycle in future studies.