bluuebunny/crossref_metadata_2025 huggingface dataset:
108 Attentional Control Deficits during Total Sleep Deprivation: Independence from Reduced Vigilant Attention
Authors: Lawrence-Sidebottom Darian , Hinson John , Whitney Paul , Honn Kimberly , Van Dongen Hans
Published: May 2021

Introduction

Total sleep deprivation (TSD) has been shown to impair performance on a two-phase attentional control task, the AX-type continuous performance task with switch (AX-CPTs). Here we investigate whether the observed AX-CPTs impairments are a downstream consequence of TSD-induced non-specific effects (e.g., reduced vigilant attention) or reflect a distinct impact on attentional control.

Methods

N=55 healthy adults (aged 26.0±0.7y; 32 women) participated in a 4-day laboratory study with 10h baseline sleep (22:00-08:00) followed by 38h TSD and then 10h recovery sleep. At baseline (09:00 day 2) and after 25h and 30h TSD (09:00 and 14:00 day 3), subjects were tested on a 10min psychomotor vigilance test (PVT), an assay of vigilant attention, and on the AX-CPTs. The AX-CPTs required subjects to differentiate designated target from non-target cue-probe pairs. In phase 1, target trials occurred frequently, which promoted prepotent anticipatory responses; in phase 2, the target pair was switched. Accuracy of responses to various different AX-CPTs trial types was expressed relative to accuracy on phase 1 neutral (non-target cue and probe) trials, which should capture non-specific impairments on the task. For all three test sessions, these relative accuracy measures, along with accuracy on phase 1 neutral trials and lapses (RT>500ms) on the PVT, were subjected to principal component analysis (PCA).

Results

The PCA revealed three statistically independent factors. Following varimax rotation, factor 1 (36.3% variance explained) and factor 3 (14.8% variance explained) each had high loadings for relative accuracy on multiple AX-CPTs trial types from phases 1 and 2; whereas factor 2 (17.9% variance explained) had high loadings for accuracy on phase 1 neutral trials, relative accuracy on phase 1 target trials, and PVT lapses.

Conclusion

These results indicate a statistical separation between AX-CPTs phase 1 neutral trials and phase 1 target trials, in conjunction with PVT lapses, versus the various other AX-CPTs trial types. This suggests a dissociation between TSD-induced, non-specific impairments on the task—potentially related to reduced vigilant attention—and TSD-induced specific impairments related to attentional control. Thus, TSD-induced deficits in attentional control are unlikely to be a downstream consequence of non-specific impairments.

Support (if any)

CDMRP grant W81XWH-16-1-0319
122 Different Duration Psychomotor Vigilance Tests Show Robust Stable Relationships Across Sleep Loss That Deteriorate in Recovery
Authors: Antler Caroline , Yamazaki Erika , Casale Courtney , Brieva Tess , Goel Namni
Published: May 2021

Introduction

The Psychomotor Vigilance Test (PVT), a behavioral attention measure widely used to capture sleep loss deficits, is available in 10-minute (PVT10) and 3-minute (PVT3) versions. The PVT3 is a briefer and presumably comparable assessment to the more commonly used PVT10 yet the relationship between the measures from the two versions across specific time points and in recovery after sleep loss has not been investigated. Repeated measures correlation (rmcorr) evaluated within-individual associations between measures on the PVT10 and PVT3 throughout a highly controlled sleep deprivation study.

Methods

Forty-one healthy adults (ages 21-49; mean±SD, 33.9±8.9y; 18 females) participated in a 13-night experiment consisting of 2 baseline nights (10h-12h time in bed, TIB) followed by 5 sleep restriction (SR1-5) nights (4h TIB), 4 recovery nights (R1-R4; 12h TIB), and 36h total sleep deprivation (TSD). A neurobehavioral test battery, including the PVT10 and PVT3 was completed every 2h during wakefulness. Rmcorr compared PVT10 and PVT3 lapses (reaction time [RT] >355ms [PVT3] or >500ms [PVT10]) and response speed (1/RT) by examining correlations by day (e.g., baseline day 2) and by time point (e.g., 1000h-2000h). Rmcorr ranges were as follows: 0.1-0.3, small; 0.3-0.5, moderate; 0.5-0.7, large; 0.7-0.9, very large.

Results

All time point correlations (1000h-2000h) were significant (moderate to large for lapses; large to very large for 1/RT). Lapses demonstrated large correlations during R1, moderate correlations during SR1-SR5 and TSD, and small correlations during R2 and R4, and showed no significant correlations during baseline or R3. 1/RT correlations were large for SR1-SR4 and TSD, moderate for SR5 and R1-R4, and small for baseline.

Conclusion

The various PVT relationships were consistently strong at specific times of day throughout the study. In addition, higher correlations observed for 1/RT relative to lapses and during SR and TSD relative to baseline and recovery suggest that the PVT10 and PVT3 are most similar and best follow performance when most individuals are experiencing behavioral attention deficits during sleep loss. Both measures track SR and TSD performance well, with 1/RT presenting as more comparable between the PVT10 and PVT3.

Support (if any)

ONR Award N00014-11-1-0361; NIH UL1TR000003; NASA NNX14AN49G and 80NSSC20K0243; NIHR01DK117488
125 Increased plasma renin activity during wake in a repetitive sleep restriction protocol
Authors: Yang Huan , Vazquez Michael , Haack Monika , Mullington Janet
Published: May 2021

Introduction

Insufficient sleep is associated with an increased risk of hypertension. It is well established that long-term BP regulation is modulated by the renin-angiotensin-aldosterone system (RAAS) and chronic kidney disease is a strong independent risk factor for development of cardiovascular disease. This study investigated the biomarkers of RAAS and renal function during repetitive exposures to controlled, experimental sleep restriction (SR). We hypothesized an upregulation of RAAS and increased markers of impaired renal function.

Methods

Twenty-one healthy participants (11 women, average age 31±2 years) completed the 22-day in-hospital SR protocol: permitted 4h of sleep/night from 0300-0700 for 3 nights followed by a recovery sleep, repeated 4 times. Blood samples were collected and plasma renin activity (PRA) was assessed in the morning (7:05am) and in the evening before bedtime (22:45pm) at baseline, experimental days (3rd day of each of the 4 blocks), and recovery. Urinary albumin to creatinine ratio (ACR) was measured from 24-h urinary collection at baseline, first and fourth SR blocks. Estimated glomerulus filtration rate (eGFR) was calculated based on the serum cystatin C levels at baseline and last block of SR.

Results

Percent change of evening PRA significantly increased during 4 blocks of SR and recovery (SR effect p=0.039), but not morning PRA (SR effect p=0.34). Specifically, evening PRA increased up to 98.4% in the first (p<0.01), 61.3% in the second (p=0.04) SR blocks, and 57.5% (p=0.05) in recovery. Urinary ACR showed no significant changes during first or fourth SR blocks (SR effect p=0.28). In addition, eGFR did not change in the fourth SR block compared to BL (paired t-test, p=0.27).

Conclusion

We did not see increased markers of impaired renal function (ACR or eGFR). Rather, short-term repetitive exposures to SR significantly increased percent change of PRA measured before bedtime, and evening PRA did not return to BL level during recovery. Our results suggested that sleep deficiency may contribute to hypertension through upregulation of RAAS during wake time.

Support (if any)

SRSF (CDA to Huan Yang), NIH (R01HL106782 to Dr. Janet Mullington), Harvard Catalyst, Harvard Clinical and Translational Science Center (UL1TR001102).
130 Individual Differences in Skin Temperature Responses to Cold Pressor Stress During Sleep Restriction and Circadian Misalignment
Authors: Linton Sabrina , Sprecher Kate , Depner Christopher , Burke Tina , Dorrestein Pieter , Fleshner Monika , Knight Rob , Lowry Christopher , Turek Fred , Vitaterna Martha , Wright Kenneth
Published: May 2021

Introduction

Individual differences in cognition during sleep restriction and circadian misalignment have been shown to be trait-like. Here we explored the consistency of individual differences in cardiovascular responses to the cold pressor test (CPT) measured by changes in the distal-proximal skin temperature gradient (DPG) using the contralateral hand to that immersed in the ice water bath, which reflects a reflex cutaneous vasoconstriction.

Methods

Eighteen healthy participants (8 females) mean (±SD) age 25.28 (±4.3), underwent two identical in-laboratory combined sleep restriction and circadian misalignment protocols preceded by an 8h baseline in-laboratory sleep opportunity. The participants were given a 3h sleep opportunity on night 2 and a 3h sleep opportunity on days 3 and 4 followed by recovery sleep. The CPT occurred the morning after the baseline sleep opportunity and the morning before recovery sleep. Participants maintained a seated posture beginning 30 min prior to the CPT and skin temperature was assessed starting 15 min before until 45 min after the CPT. DPG (proximal=subclavicular; distal=hand palmar) data were averaged into 3 min bins. Changes in DPG from pre-CPT and 5 min post-CPT were assessed as the primary outcome using mixed-model ANOVAs. Intra-class correlation coefficients (ICC) were calculated to measure consistency of individual differences for DPG responses.

Results

Mixed-model ANOVA revealed significant effects of time and combined sleep restriction and circadian misalignment on DPG during the CPT (both p<0.05), such that the DPG was wider (i.e., more negative) post-CPT and during sleep restriction and circadian misalignment. Participants showed moderately consistent DPG responses across visits 1 and 2 at baseline (ICC=0.59) and substantially consistent DPG responses during sleep restriction and circadian misalignment (ICC=0.67). Further, participants showed moderately consistent DPG responses when comparing changes between baseline and sleep restriction and circadian misalignment across visits (ICC=0.58).

Conclusion

Findings support that combined sleep restriction and circadian misalignment is associated with sympathetic activation and that individual differences in the DPG response to cold pressor stress are consistent.

Support (if any)

Office of Naval Research MURI grant N00014-15-1-2809, NIH/NCATS Colorado CTSA Grant UL1TR002535
135 One night of mild sleep restriction affects EEG and behavioural measures of vigilance
Authors: Gibbings Aaron , Ray Laura , Berberian Nareg , Zandi Ali Shahidi , Owen Adrian , Comeau Felix , Fogel Stuart
Published: May 2021

Introduction

Much is known about the behavioural and cognitive consequences of chronic sleep loss but relatively little is known about the changes in brain activity associated with reduced vigilance after mild and acute sleep loss. Mild and acute sleep loss is generally thought to be innocuous despite research showing emotional processing, visual attention and behavioural responding are all negatively impacted by even small amounts of sleep loss. The current study investigated behavioural, cognitive, and electrophysiological consequences of mild (i.e., a couple of hours) and acute (i.e., a single night) sleep loss via simultaneous behavioural and physiological measures of vigilance.

Methods

Participants (N = 23; 18 females, Mage = 22 ± 3 years) came into the lab (from ~12 pm to 3 pm) for two testing days after sleeping from 1 am to 6 am (Sleep Restriction), or from 12 am to 9 am (Normally Rested). Brain activity was recorded using electroencephalography (EEG) from 15 scalp derivations, while vigilance was assessed simultaneously using the psychomotor vigilance task (PVT).

Results

Vigilance was reduced in the Sleep Restricted vs. Normally Rested condition, (F(1,22)=9.02, p=0.007). This was exacerbated over the course of performing the PVT, (F(5,110)=8.12, p<0.001). Sleep Restriction also resulted in increased intensity of alpha burst activity compared to the Normally Rested condition (F(1,20)=6.19, p=0.022). Lastly, EEG spectral power differed between restriction sleep conditions across deepening stages of sleep onset, particularly for frequencies that reflect arousal e.g., delta, alpha and beta activity (F(1,20)>5.52, p<0.029).

Conclusion

These results suggest that even a small amount of sleep loss, occurring on only one night significantly reduces vigilance and impacts the physiology of the brain in ways that reflect reduced arousal. Understanding the neural correlates and cognitive processes associated with sleep loss may lead to important advancements in identifying and preventing potentially deleterious or dangerous, sleep-related lapses in vigilance (e.g., in the classroom, workplace), and when lapses in vigilance can be life-threatening (e.g., while driving).

Support (if any):
137 Recovery Dynamics in a Biomathematical Model of Fatigue
Authors: McCauley Mark , McCauley Peter , Van Dongen Hans
Published: May 2021

Introduction

In commercial aviation and other operational settings where biomathematical models of fatigue are used for fatigue risk management, accurate prediction of recovery during rest periods following duty periods with sleep loss and/or circadian misalignment is critical. The recuperative potential of recovery sleep is influenced by a variety of factors, including long-term, allostatic effects of prior sleep/wake history. For example, recovery tends to be slower after sustained sleep restriction versus acute total sleep deprivation. Capturing such dynamics has proven to be challenging.

Methods

Here we focus on the dynamic biomathematical model of McCauley et al. (2013). In addition to a circadian process, this model features differential equations for sleep/wake regulation including a short-term sleep homeostatic process capturing change in the order of hours/days and a long-term allostatic process capturing change in the order of days/weeks. The allostatic process modulates the dynamics of the homeostatic process by shifting its equilibrium setpoint, which addresses recently observed phenomena such as reduced vulnerability to sleep loss after banking sleep. It also differentiates the build-up and recovery rates of fatigue under conditions of chronic sleep restriction versus acute total sleep deprivation; nonetheless, it does not accurately predict the disproportionately rapid recovery seen after total sleep deprivation. To improve the model, we hypothesized that the homeostatic process may also modulate the allostatic process, with the magnitude of this effect scaling as a function of time awake.

Results

To test our hypothesis, we added a parameter to the model to capture modulation by the homeostatic process of the allostatic process build-up during wakefulness and dissipation during sleep. Parameter estimation using previously published laboratory datasets of fatigue showed this parameter as significantly different from zero (p<0.05) and yielding a 10%–20% improvement in goodness-of-fit for recovery without adversely affecting goodness-of-fit for pre-recovery days.

Conclusion

Inclusion of a modulation effect of the allostatic process by the homeostatic process improved prediction accuracy in a variety of sleep loss and circadian misalignment scenarios. In addition to operational relevance for duty/rest scheduling, this finding has implications for understanding mechanisms underlying the homeostatic and allostatic processes of sleep/wake regulation.

Support (if any)

Federal Express Corporation
139 Does Extraversion Predict Subjective Ratings of Sleepiness and Performance During Sleep Deprivation?
Authors: Schneider Ben , Honn Kimberly , Van Dongen Hans
Published: May 2021

Introduction

Repeated exposure to total sleep deprivation (TSD) within individuals has demonstrated task-specific, trait-like individual differences in cognitive impairment and subjective sleepiness. Research has suggested that introversion/extraversion may predict individual vulnerability to TSD. While previous analyses have found that extraversion does not reliably predict objective performance impairment on the psychomotor vigilance test (PVT) during TSD, it is not known whether extraversion may predict individuals’ subjective responses to TSD, including subjective ratings of sleepiness, fatigue, mood, performance, and effort.

Methods

N=21 healthy adults (aged 21-38; 9 women) completed three 4-day/3-night laboratory sessions – each including a baseline night, 36h TSD period, and recovery night –separated by at least 2 weeks each. Two of the sessions were preceded by a week of sleep extension (12h nightly sleep opportunities), while one session was preceded by a week of sleep restriction (6h nightly sleep opportunities), in randomized, counterbalanced order; only the sleep extension sessions are used here. Prior to the experiment, subjects filled out the Eysenck Personality Questionnaire (EPQ), which yielded an extraversion score; one subject did not complete the questionnaire and was excluded from analyses. Every 2h during TSD, subjects completed a 60min neurobehavioral test battery. At the beginning of the test battery, subjects completed the Karolinksa Sleepiness Scale (KSS) and visual analog scales of mood and fatigue (VAS-M and VAS-F). At the end of the test battery, subjects completed self-ratings of their performance (1–7 scale) and effort (1–4 scale). The relationship between extraversion and subjective scores after sleep deprivation (average over last 24h of 36h TSD period) relative to baseline (average over first 12h of TSD period) was analyzed using mixed-effects analysis of covariance, controlling for order, with a random effect over subjects on the intercept.

Results

No significant relationships were observed between extraversion and subjective estimates of sleepiness (KSS, p=0.45), fatigue (VAS-F, p=0.80), mood (VAS-M, p=0.14), performance (p=0.89), and effort (p=0.93).

Conclusion

These results indicate that extraversion is not a reliable predictor of trait-like individual differences in subjective vulnerability to 36h TSD.

Support (if any)

NASA grant NAG9-1161, CDMRP grant W81XWH-20-1-0442
142 Prenatal Sleep Quality and Infant Sleep: A Longitudinal Study
Authors: Burdayron Rebecca , Pennestri Marie-Helene , Keys Elizabeth , Tomfohr-Madsen Lianne , Giesbrecht Gerald
Published: May 2021

Introduction

Poor sleep quality is common during pregnancy and can increase the risk of adverse obstetric and fetal outcomes. Existing research on the association between prenatal sleep and infant sleep is scarce and has focused on other aspects of prenatal sleep such as sleep duration, chronotype, and insomnia symptoms. To our knowledge, no studies have examined the association between prenatal sleep quality and infant sleep outcomes. Thus, this study aimed to investigate whether maternal sleep quality during pregnancy was prospectively associated with infant sleep dimensions, independent of relevant covariates.

Methods

Participants were a subset of 272 mother-infant dyads enrolled in an ongoing cohort study. Maternal prenatal sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) in early to mid- (M gestational age = 15.12 ± 3.56 weeks) and late- (M gestational age = 32.44 ± 0.99 weeks) pregnancy. Mothers completed the Brief Infant Sleep Questionnaire (BISQ) at 3, 6, and 12 months postpartum. The following infant sleep parameters were assessed: sleep duration (day, night, 24-hour), number of night awakenings, and wake after sleep onset. Prenatal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale (EPDS) at both pregnancy time points. Other covariates included maternal age at enrollment, infant age, parity, and co-sleeping status.

Results

Generalized estimating equations (GEE) models revealed that poorer maternal sleep quality during early-to-mid pregnancy did not significantly predict infant sleep parameters after adjustment for covariates (p > .05). However, in late pregnancy, poorer maternal sleep quality significantly predicted shorter 24-hour sleep duration and longer wake after sleep onset, but not daytime sleep duration, nighttime sleep duration, and number of night awakenings (p < .05).

Conclusion

Study findings advance our understanding of the prospective link between maternal prenatal sleep quality and infant sleep. Results indicate that maternal sleep quality during late gestation may play a role in the development of infant sleep patterns. These findings have important implications for intervention efforts targeting maternal sleep quality during pregnancy. Future research should use objective measures of sleep, such as actigraphy, to better elucidate the effects of prenatal sleep quality on infant sleep outcomes.

Support (if any)

The Canadian Institutes of Health Research (CIHR)
150 Impact of Behavioral Disorders and their Pharmacological Treatment on the Maturational Trajectories of NREM Slow Wave Activity
Authors: Fernandez-Mendoza Julio , Ricci Anna , He Fan , Fang Jidong , Calhoun Susan , Cain Patricia , Vgontzas Alexandros , Liao Duanping , Bixler Edward
Published: May 2021

Introduction

Slow wave activity (SWA) in the delta (0.4-4 Hz) frequency range declines in typically developing (TD) children as they transition to adolescence. However, it remains unknown whether the maturational trajectory of NREM delta power differs between TD youth and those with psychiatric/behavioral disorders.

Methods

We analyzed the sleep EEG of 664 subjects aged 6 to 21 (46.8% female, 24.7% racial/ethnic minority) from the Penn State Child Cohort, of whom 449 were TD, 123 were un-medicated and diagnosed with psychiatric/behavioral disorders, and 92 were medicated with stimulants, anti-depressants, anxiolytics, sedatives and/or anti-psychotics. Multivariable regression models adjusting for sex, race/ethnicity, BMI, AHI and PSG system tested the age-related trajectories of NREM delta power within each diagnostic group.

Results

Delta power in TD and un-medicated youth showed cubic age-related trajectories (both p-cubic<0.05). In TD youth, delta power was highest at age 6.6 and lowest at age 19.9, while in un-medicated youth it was highest at age 8.9 and lowest at age 18.6. The decreasing slope in delta power was 39.7% steeper in un-medicated youth (-22422 ± 5891/year, p<0.01) than TD youth (-16047 ± 2605/year, p<0.01). Delta power in medicated youth showed a distinct linearly decreasing trajectory (-13518 ± 4597/year, p-linear<0.01) from age 6 (highest) to age 21 (lowest).

Conclusion

TD and un-medicated youth with psychiatric/behavioral disorders show SWA trajectories typical of brain maturation biomarkers (e.g., gray matter volume), characterized by a decreasing slope at the onset of puberty that reaches its nadir by late adolescence. However, SWA in un-medicated youth peaks two years later and reaches its nadir a year earlier than in TD youth. Thus, while TD children experience a smooth decline in SWA in the transition to adolescence, those with psychiatric/behavioral disorders experience a faster steep decline. In contrast, SWA in medicated youth appears to be dampened in early childhood and its slope linearly decreases with age. These data suggest that these youth may have a more severe disorder requiring pharmacological treatment, that the latter produces greater cortical arousability reflected in lower SWA power, and/or that psychoactive medications directly impact normal neurodevelopmental processes (e.g., synaptic pruning).

Support (if any)

NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127
155 Evening blue light exposure, maternal glucose and infant birth weight
Authors: Balserak Bilgay Izci , Hermann Renata , Buhimschi Catalin , Park Chang Gi
Published: May 2021

Introduction

During pregnancy, the use of light-emitting electronic devices before bedtime may contribute to or exacerbate sleep problems. Exposure to blue-wavelength light in particular from these devices may affect sleep by inhibiting melatonin release and causing neurophysiologic arousal which may affect the uterus environment. However, the health consequences of blue-wavelength light on maternal glucose level and fetus development is poorly understood. The purpose of this study was to test the hypothesis that nocturnal blue-light exposure is associated with maternal glucose level and infant’s birth weight.

Methods

A group of pregnant women aged 24-39 years old who wore 7-day actigraphy, and completed questionnaires including Pittsburgh Sleep Quality Index participated in the study. Infant’s birth weight (n=41) and fasting glucose level (n=30) was abstracted from mothers’ medical charts. Blue-wavelength light exposure was obtained from actigraphy recordings. Unadjusted linear regression analyses were performed to determine sleep characteristics that were associated with fasting glucose and infant’s weight (p<0.2). Using infant’s birth weight and fasting glucose as outcome variables, confounding variables were evaluated in full linear regression models as independent variables.

Results

The mean gestational age was 30.66 (Standard Deviation (SD) 3.46) weeks. The mean fasting glucose, infant’s birth weight and gestational age at delivery were 95.73 mg/dL (SD 24.68), 3261 gr (SD 470) and 38.78 (SD 1.69), respectively. In unadjusted analysis, infant birth weight was significantly associated with only blue light value (μW/cm2) (β=76.98, p=0.002) and remained significant (β=78.26, p=0.003) after adjusting for BMI, maternal age and gestational diabetes. Fasting glucose was associated with blue light value (β=2.81, p=0.055) and became significantly associated (β=78.26, p=0.003) after adjusting for sleep duration, parity and gestational diabetes. The coefficient demonstrates that for each unit increase in the evening blue light exposure, there is a 78 gr increase in infant weight after controlling the effect of maternal age, BMI and gestational diabetes.

Conclusion

Evening blue light exposure during mid and late pregnancy may alter maternal glucose regulation and placental nutrient transport to fetus, but these remain to be studied. This study may shed light on future research on the effect of evening light exposure on pregnancy outcomes.

Support (if any)

National Institutes of Health (R00-NR013187)
156 Evening Light-Induced Circadian Phase Shift in Preschool-Aged Children
Authors: Hartstein Lauren , Akacem Lameese , Behn Cecilia Diniz , Stowe Shelby , Wright Kenneth , LeBourgeois Monique
Published: May 2021

Introduction

In adults, exposure to light at night delays the timing of the circadian clock in a dose-dependent manner with intensity. Although children’s melatonin levels are highly suppressed by evening bright light, the sensitivity of young children’s circadian timing to evening light is unknown. This research aimed to establish an illuminance response curve for phase delay in preschool children as a result of exposure to varying light intensities in the hour before bedtime.

Methods

Healthy children (n=36, 3.0 – 4.9 years, 39% males), participated in a 10-day protocol. For 7 days, children followed a strict parent-selected sleep schedule. On Days 8-10, an in-home dim-light assessment was performed. On Day 8, dim light melatonin onset (DLMO) was measured through saliva samples collected in 20-30-min intervals throughout the evening until 1-h past habitual bedtime. On Day 9, children were exposed to a white light stimulus (semi-randomly assigned from 5lx to 5000lx) for 1-h before their habitual bedtime, and saliva was collected before, during, and after the exposure. On Day 10, children provided saliva samples in the evening for 2.5-h past bedtime for a final DLMO assessment. Phase angle of entrainment (habitual bedtime – DLMObaseline) and circadian phase delay (DLMOfinal – DLMObaseline) were computed.

Results

Final DLMO (Day 10) shifted between -8 and 123 minutes (M = 56.1 +/- 33.6 min; negative value = phase advance, positive value = phase delay) compared with DLMO at baseline (Day 8). Raw phase shift did not demonstrate a dose-dependent relationship with light intensity. Rather, we observed a robust phase delay across all intensities.

Conclusion

These data suggest preschoolers’ circadian clocks are immensely sensitive to a large range of light intensities, which may be mechanistically influenced by less mature ophthalmologic features (e.g. clearer lenses, larger pupils). With young children’s ever-growing use of light-emitting devices and evening exposure to artificial lighting, as well as the prevalence of behavioral sleep problems, these findings may inform recommendations for parents on the effects of evening light exposure on sleep timing in early childhood.

Support (if any)

This research was supported with funds from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (R01-HD087707).
157 The Circadian Variation of Sleep in Postmenopausal Women
Authors: Carballo Rafael Perez Medina , Kosmadopoulos Anastasi , Robert Manon , Boivin Diane
Published: May 2021

Introduction

During menopause, 40-60% of women report sleep complaints. Despite the fact that menopause is associated with fluctuations in sex hormones that can affect circadian physiology, the role of circadian factors in sleep disturbances after menopause is not well understood. The present study aims to understand the circadian variation of sleep occurring after menopause.

Methods

Eight healthy postmenopausal women (PMW; 54.8±3.4 years, one taking hormones) without sleep complaints were enrolled and compared to previously-collected data from 12 healthy young women (YW; 25.8±3.4 years) in mid-follicular phase. Following an 8-h baseline sleep period aligned to their habitual sleep times, participants underwent a 48-h (PMW) or 72-h (YW) ultradian sleep-wake cycle procedure (USW) with 60-min wake episodes alternating with 60-min nap opportunities. Sleep was recorded with polysomnography. Circadian parameters (amplitude, phase) of core body temperature (CBT) and sleep were assessed and compared using mixed-effects linear models on the first 48 hours of USW. Sleep parameters, including total sleep time (TST), arousals, sleep onset latency (SOL), stages N1, N2, N3, REM, and wake, were compared between groups during baseline and USW.

Results

PMW presented earlier habitual bedtimes (23:07±00:11 vs 00:13±00:12) and rise-times (07:07±00:11 vs 08:13±00:12) compared to YW (p=0.005). There were no differences in amplitude, phase, or phase angle of CBT. An advanced acrophase of REM sleep (p=0.034) and lower amplitudes of TST, arousals, SOL, N3, and wake, were observed in PMW vs YW (p≤0.05). During baseline, PMW presented more stage N1 (p=0.030) and arousals (p<0.001) than YW. During USW, group effects were observed, with more stage N1 (p=0.007) and N2 (p=0.0007) in PMW vs YW. Significant interactions showed greater TST (p=0.009), shorter SOL (p=0.001), and more arousals (p=0.027) in PMW during the habitual day.

Conclusion

The primary finding in this small group of PMW with no sleep complaints was a general increase in light sleep and arousals across circadian phases. No differences in CBT rhythms were observed, whereas small differences in the circadian variation of TST, N3, and REM sleep were observed. Further studies are needed to clarify the role of circadian processes on sleep in PMW.

Support (if any)

Study supported by the Canadian Institutes of Health Research.
168 Prevalence and Severity of Sleep Disruption Amongst Asylum-Seekers in South Florida
Authors: Jones Sara , Arora Arshia , Brooks Jordan , Easwaran Lavanya , Davis Jenna , Engle Kyrra , Johnson Catherine , Kather Josefina , Nunes Antonio , Radhakrishnan Ramya , Skelton Alexander , Symes Stephen
Published: May 2021

Introduction

While research suggests that asylum-seekers often present with a high level of medical and psychological needs, there is a dearth of research exploring sleep quality in this population, and, accordingly, the role that the sleep medicine community may be able to play in alleviating the suffering of this population. Therefore, this study aims to assess the prevalence of sleep disruption amongst asylum-seekers presenting to a South Florida clinic and to categorize these disruptions according to severity and type.

Methods

This is a cross-sectional study utilizing medical affidavits for asylum seekers in South Florida from 2018-2020 (n=54). Affidavits were reviewed for narrative descriptions of sleep quality and information from validated screeners regarding sleep; demographic information was also collected. Affidavits were excluded if they did not include itemized answers to screening questions.

Results

Out of 54 asylum-seekers (31% male, median age=34.5 years), 72.2% reported sleep disturbance. 38.9% reported nightmares, 66.7% reported insomnia of any type, and 29.6% reported severe insomnia. Asylum-seekers that screened positive for post-traumatic stress disorder (PTSD) were more likely to report ongoing sleep disturbance than asylum-seekers that screened negative for PTSD (p=.004). Sleep disturbance prevalence did not vary significantly by gender identity or country of origin.

Conclusion

This study reveals a high prevalence of sleep disruption amongst asylum-seekers in South Florida. The asylum-seekers in our study were more likely to experience insomnia than nightmares, but many experienced both; sleep disturbance was significantly associated with screening positive for PTSD. Our findings suggest that physicians working with asylum-seekers should ask about sleep quality and offer appropriate care. Directions for further research include investigating how poor sleep quality impacts the health and wellbeing of asylum-seekers.

Support (if any)

None
172 Sleep Disparities in Preschool-Aged Children
Authors: Holmes Jennifer , Hanron Olivia , Spencer Rebecca
Published: May 2021

Introduction

Sleep is known to be associated with socioeconomic status (SES) in older children and adults with those from lower SES households often experiencing poorer sleep quality. Whether this disparity exists in early childhood is relatively unknown, despite being an important age marked by sleep transitions and the establishment of lifelong sleep habits. Furthermore, it is a critical period for cognitive development and learning, which are supported by sleep. Here, we explore associations between sleep and SES in a preschool population. We hypothesized that children from lower SES households would exhibit shorter overnight sleep, longer and more frequent naps, and shorter 24-hr sleep. Additionally, we considered racial and ethnic disparities in sleep which can be confounded with SES in some samples.

Methods

Child (n=441; M age=51.9mo; 45.4% female) sleep was measured objectively using actigraph watches, worn for 3-16 days (M=9.5 days). Caregivers reported child demographics and household data. Race/ethnicity of our sample was 72% White, 10.2% Black, 17.8% other or more than one race, and 28.4% identified as Hispanic. 20.1% of our sample was categorized as low SES. Effects of SES and race/ethnicity on continuous sleep measures were assessed using multiple regression models, with age and gender as covariates. Nap habituality was assessed using chi-square tests.

Results

Lower SES was associated with shorter nighttime sleep duration, longer nap duration, and shorter 24-hr sleep duration (p’s<.001). Children from lower SES households were also more likely to nap habitually (p=.04) as were Hispanic children (p<.001). Hispanic children also tended to have longer nap bouts (p=.002). Hispanic and Black children on average had shorter overnight sleep durations than White children (p’s<.04), but their 24-hr sleep did not differ.

Conclusion

SES-related sleep disparities were present in this preschool population, with lower SES children exhibiting poorer sleep. When controlling for SES, Hispanic children tended to sleep less overnight which was compensated for by longer, more frequent naps. This underscores the necessity of naps for some children to achieve adequate sleep. Future directions will explore the relationship between parenting factors and sleep, such as bedtime routines and parent knowledge surrounding child sleep needs.

Support (if any)

NIH R01 HL111695
181 Sleep health concordance among socioeconomically disadvantaged caregiver-child dyads
Authors: Covington Lauren , Brewer Benjamin , Blair Rachel , Hoopes Elissa , Laurenceau Jean-Philippe , Patterson Freda
Published: May 2021

Introduction

Child and caregiver sleep typically occurs within a family system. Disadvantaged families experience disproportionately poorer sleep health than more advantaged families. The extent to which objectively measured sleep health metrics (e.g. duration, timing, regularity, efficiency) are concordant within disadvantaged family systems, such as caregiver-child dyads, is not clear. To address this gap, this study aimed to: (1) characterize sleep health metrics, and (2) identify levels of sleep health concordance among disadvantaged caregiver-child dyads.

Methods

23 disadvantaged dyads were recruited from Philadelphia and Delaware communities. Dyads were eligible if the child was between 6-14 years, slept in the same house as the caregiver at least four nights/week, had no diagnosis of a sleep disorder or use of sleep medication, and qualified for federally funded food assistance programs (e.g., food stamps, WIC or SNAP benefits). Sleep health of the dyads was objectively measured for 7-14 days. Sleep metrics used to characterize the sample were: nighttime sleep duration (hours), time-to-bed, sleep regularity (standard deviation of sleep duration), sleep midpoint (halfway point between sleep onset and wake time) and efficiency (percentage of time spent asleep versus awake). Concordance in sleep health metrics within dyads was calculated using Pearson’s correlation coefficients of the average sleep metrics over the monitoring period.

Results

Children (46.2% female) slept, on average, 7.96 hours per night, with 1.25 hours of nightly sleep variability, bedtime of 10:47 PM, sleep midpoint of 2:56 AM, and sleep efficiency of 83.55%. Caregivers (mean age = 40.5 years, 85.0% female) slept, on average, 6.92 hours per night, with 1.22 hours of nightly sleep variability, bedtime of 11:24 PM, sleep midpoint of 3:04 AM, and sleep efficiency of 76.29%. Bedtime (r = 0.19, p < 0.001), sleep midpoint (r = 0.39, p < 0.001), and sleep efficiency (r = 0.24, p < 0.001) were significantly concordant among caregiver-child dyads.

Conclusion

Given their level of concordance, bedtime, sleep midpoint and efficiency are modifiable factors of sleep health in disadvantaged dyads that could be targeted using family versus individual level interventions.

Support (if any)

University of Delaware General University Research Grant and School of Nursing SEED funding.
188 Racial Disparities in Sleep During the COVID-19 Pandemic
Authors: Harra Ryan , Snyder Hope , Thurmon Casey , Hire Veronica , Walker Jamie , Vargas Ivan
Published: May 2021

Introduction

The purpose of the present study was to estimate average sleep duration and sleep disturbance in the United States during the COVID-19 pandemic. In addition, we investigated whether sleep varied as a function of sociodemographic variables, in particular race. Long standing disparities in condition and available resources between racial demographics often lead to disparities in health. At the advent of a pandemic, which strains these systems further, it is important to assess whether or not racial disparities persist. This is important given that racial groups are likely affected by the pandemic, both directly and indirectly, in various ways. Here, we plan to at least assess whether there are any disparities with regard to sleep.

Methods

4,048 adults (Mage = 45.8 years; 79% women) completed an online survey during April – June 2020. The final sample’s self-reported race/ethnicity consisted of 84% White, 5.1% Black, 3.4% LatinX, 4.2% Asian or Asian American, and 2.9% Multi-racial. Sleep disturbance was assessed using a retrospective sleep diary and the Insomnia Severity Index (ISI).

Results

Average sleep duration in the sample was 7.1 hours. Participants reported taking on average 32 minutes (SD = 38 mins) to fall asleep and reported waking up for 32 minutes (SD = 53 mins) during the night. Approximately 17% of the sample endorsed clinically elevated insomnia symptoms (based on the ISI ≥ 15 cut-off). With regard to racial differences, shorter total sleep time (TST), longer sleep latencies (SL), and greater total ISI scores were observed in Black (mean TST = 6.4 hours; SL = 37.7 minutes; ISI Total = 9.8) and LatinX (mean TST = 6.9 hours; SL = 37.1 minutes; ISI Total = 9.6) participants relative to White participants (Mean TST = 7.1 hours; SL = 30.9 minutes; ISI Total = 8.4). All p’s < 0.05.

Conclusion

Sociodemographic variables, particularly race, should be considered when estimating the relative impact of sleep on overall health. These findings are significant as they may have implications for a number of health disparities observed in the United States, especially during the COVID-19 pandemic.

Support (if any)

Vargas: K23HL141581
200 COVID-19 Pandemic Sleep Changes Related to Social and Financial Impacts at the US-Mexico Border
Authors: Arce Ruya , Valencia Dora , Ghani Sadia , Delgadillo Marcos , Madhivanan Purnima , Krupp Karl , Ruiz John , Seixas Azizi , Jean-Louis Giardin , Killgore William , Wills Chloe , Grandner Michael
Published: May 2021

Introduction

The COVID-19 pandemic has caused major impacts to social and financial status for many people, including those living in the vulnerable US-Mexico border region. This study examined relationships between changes in sleep and perceived impacts to social and financial stability due to the pandemic.

Methods

Participants were 155 individuals who completed the Nogales Cardiometabolic Health and Sleep (NOCHES) and were contacted about completing a COVID sub-study (95% Hispanic/Latino). Participants were asked if the COVID-19 pandemic was causing them to feel more socially isolated, negatively impacting their finances, causing increased worry about finances, affecting their primary job, causing a job loss, and impacting their belief life will one day return to normal. In addition, they were asked to report the degree to which they experienced pandemic-related changes to sleep, including a regularity, overall improvement/worsening, initial and middle-of-the-night insomnia, daytime sleepiness, and napping. Logistic regression analyses were adjusted for age, sex, socioeconomics, and mental health (PHQ4).

Results

Those who kept a more regular schedule had lower odds of endorsing isolation (OR=0.32,p<0.0005) and higher odds of believing things will return to normal (OR=1.67,p=0.041). Those whose sleep improved also had lower odds of feeling isolated (OR=0.40,p=0.005). Those with worsened sleep had increased odds of feeling isolated (OR=2.14,p=0.023), experiencing a financial impact (OR=1.85,p=0.016) and increased financial worry (OR=1.71,p=0.033), and lower odds of believing things will return to normal (OR=0.53,p=0.012). More initial insomnia was associated with isolation (OR=3.62,p=0.001), financial impact, (OR=1.89,p=0.015), financial worry (OR=1.87,p=0.016) and job impact (OR=1.95,p=0.010). More middle-of-the-night insomnia was associated with financial worry (OR=1.82,p=0.016) and job impact (OR=1.93,p=0.009). More sleepiness was associated with job loss (OR=1.84,p=0.043). More napping was associated with financial impact (OR=1.89,p=0.017) and worry (OR=1.88,p=0.017), impact to job (OR=1.89,p=0.016) or lost job (OR=1.81,p=0.041), and decreased likelihood of believing things will return to normal (OR=0.45,p=0.003).

Conclusion

Pandemic-related stress was linked with sleep disturbances. Worse sleep was indicative of increased social isolation, greater financial fears, more job-related impacts and less of a general sense that things would return to normal.

Support (if any)

Supported by T32HL007249, R01MD011600, R01DA051321
205 Changes in Sleep Due to COVID Pandemic Associated with Changes to Dietary Patterns
Authors: Ghani Sadia , Kennedy Kathryn , Seixas Azizi , Jean-Louis Giardin , Killgore William , Knowlden Adam , Wills Chloe , Grandner Michael
Published: May 2021

Introduction

The COVID-19 pandemic has affected sleep and diet for many people. The present study sought to examine potential associations between changes to sleep and eating habits during the COVID-19 pandemic.

Methods

A sample of N=419 US adults completed online surveys about sleep and COVID-19 experiences. Questions for diet asked, “since quarantine: I’m eating healthier, eating more processed foods, home-cooked meals and more regularly,” “I’m enjoying food in quarantine and I’m struggling with overeating in quarantine.” Sleep questions asked “since quarantine: I have managed to keep a regular sleep-wake schedule, my sleep has improved, I’m struggling to fall asleep, I’m waking up more during the night, I’m more sleepy during the day and I’m taking more naps during the day.” Answers were reported on a 4-point scale ranging from “strongly disagree to strongly agree.” Ordinal logistic regressions were used, adjusted for age and sex and examined each dietary variable as ordinal outcome and each sleep variable as predictor.

Results

Those who report that they kept a more regular schedule were more likely to report eating healthier (oOR=3.13, p=0.007), eating more home-cooked meals (oOR=3.19, p=0.005), and less likely to be eating more processed foods (oOR=0.39, p=0.02), struggle with overeating (oOR=0.39, p=0.02) or undereating (oOR=0.30, p=0.004) or snacking (oOR=0.25, p=0.001). Those reporting more difficulty falling asleep were less likely to be eating healthier (oOR=0.25, p=0.002) and more likely to be eating more processed foods (oOR=3.07, p=0.009) and snacking (oOr=2.36, P=0.04). Those reporting more difficulty with awakenings were less likely to report eating healthier (oOR=0.34, p=0.03) and more likely to report eating more processed foods (oOR=4.52, p=0.001). Those with more sleepiness were less likely to report eating healthier (oOR=0.29, p=0.01) and more homecooked meals (oOR=0.40, p=0.046) and more likely to report eating more processed foods (oOR=6.42, p<0.0005), overeating (oOR=3.63, p=0.01) and snacking (oOR=5.81, p=0.001).

Conclusion

Research studying psychological, behavioral and environmental factors that are contributing to changes in sleep and dietary patterns is especially important during a pandemic that has forced people into changes that they may not have been prepared for and which may result in long-term health outcomes.

Support (if any)

T32HL007249, R01MD011600, R01DA051321