bluuebunny/crossref_metadata_2025_split huggingface dataset:
0290 Caffeine Efficacy Varies as a Function of Individual Vulnerability to Sleep Restriction
Authors: Demiral S B , Doty T J , Ratcliffe R H , Hughes J D , Balkin T J , Capaldi V F 
Published: May 2020

Abstract

Introduction
We previously showed that relative to placebo (PL), caffeine (CAF) significantly improved psychomotor vigilance task (PVT) reaction time (RT) during the first 2 days (ACUTE phase), but not during the last 3 days (CHRONIC phase) of sleep restriction (SR) (Doty et al., 2018). However, while individual differences in RT during sleep deprivation have been previously documented, the interaction between CAF and individual vulnerability (VUL) during SR on PVT-RT is not well-known.

Methods
For statistical analysis, we computed trends in RTs (SLOPE) as follows; baseline, 1st and the 2nd SR days to represent ACUTE phase, and the 2nd, 3rd, 4th and 5th SR days for CHRONIC phase. Participants in each GROUP (CAF or PL) were split into 2 for VUL; high vulnerable (HIGHVUL), and low vulnerable (LOWVUL), depending on the number of minor lapses made during SR. We used 3-way ANOVA model with independent measures (2x2x2; GROUPxVULxPHASE) and a dependent measure (SLOPE).

Results
We found a main effect of VUL (F=12.69, p&lt;0.001), an interaction between GROUP and PHASE (F=12.95, p&lt;0.001) and an interaction between VUL, GROUP, and PHASE (F=8.04, p&lt;.01). Resolving this 3-way interaction for ACUTE revealed a main effect of VUL (F=9.34, p&lt;.005), a main effect of GROUP (F=5.96, p&lt;.05). Although the interaction between VUL and GROUP failed to achieve significance (F=3.46, p=0.073), only for the LOWVUL, PL participants were significantly higher than CAF, p&lt;0.01)). Resolving the 3-way interaction for CHRONIC revealed a main effect of GROUP (F=8.95, p&lt;0.01), no significant of VUL (F=3.36, p=0.077) and an interaction between VUL and GROUP (F=6.11, p&lt;0.05). Resolving this interaction showed that only for the LOWVUL participants in CAF, the slope was higher than PL (p&lt;.001).

Conclusion
Performance enhancing effects of caffeine were only evident for low vulnerability participants, and for only the first few days of sleep restriction. At the tested dose level, caffeine did not result in meaningful improvements in performance in highly vulnerable participants during the sleep restriction period.

Support
Department of Defense Military Operational Medicine Research Program (MOMRP)
0294 Baseline Response Speed Predicts Locus Coeruleus Integrity Change After Sleep Deprivation
Authors: Quan P , Lei H , Wang J , Liu W , Zhang X , Dinges D , Rao H 
Published: May 2020

Abstract

Introduction
Locus coeruleus (LC) is the major source of norepinephrine (NE) in the brain, which plays a key role in maintaining arousal and alertness. Sleep loss significantly impairs arousal and alertness. However, it is unknown whether sleep loss disrupts LC integrity, which can be measured non-invasively by diffusion tensor imaging (DTI). In the current study, we used DTI to examine the effects of one night of acute total sleep deprivation (TSD) on fractional anisotropy (FA), an index reflecting fiber density, axonal diameter and myelination.

Methods
We analyzed DTI and psychomotor vigilance test (PVT) data from N=54 health adults (23 females, age range 21–50 years) from a well controlled in-laboratory sleep deprivation study. Participants were randomized to either a TSD condition (n=40) without sleep on night 2, or a control condition (n=14) with no sleep loss. Standard DTI scans were conducted on the morning of day 2 and day 3 between 0700h-1000h. The PVT reciprocal response time (RRT) was used to measure individual’s response speed at baseline without sleep loss. LC regions-of-interest (ROI) were defined by standard templates from Keren et al. (2009). Imaging data were analyzed using FSL toolbox.

Results
For the whole TSD group, no differences were found in the LC FA values before and after sleep deprivation (p &gt; .2). However, when dividing the TSD group to a slow group and a fast group based on their baseline PVT response speed, significantly increased LC FA were found in the slow group (p = .007) but not in the fast group (p &gt; .4). The PVT RRT negatively correlated with LC FA value changes after TSD (r = -.44, p = .004). No correlations were found between the PVT RRT and LC FA changes in the control group.

Conclusion
Our results showed that baseline vigilance response speed correlated with LC integrity change after sleep deprivation, with slower response exhibiting greater changes in LC integrity. These findings support the key role of LC-NE system in the regulation of alertness and arousal.

Support
Supported in part by NIH grants R01-HL102119, R01-MH107571, R21-AG051981. CTRC UL1RR024134, and P30-NS045839.
0295 Skeletal Muscle Diacylglycerol Accumulation and Impaired Insulin Sensitivity During Insufficient Sleep
Authors: Morton S J , Bergman B C , Zemski-Berry K A , Harrison K A , Schauer I E , Wright K P , Broussard J L 
Published: May 2020

Abstract

Introduction
Insufficient sleep impairs insulin sensitivity; however, the mechanism(s) by which this occurs are unknown. We previously reported an elevation in plasma free fatty acid concentration during insufficient sleep, suggesting dysregulated lipid metabolism. Lipid accumulation in muscle—specifically certain species of diacylglycerol (DAG)—is associated with impaired insulin sensitivity. We therefore tested the hypothesis that insufficient sleep leads to skeletal muscle DAG accumulation.

Methods
As part of an ongoing study, thirteen sedentary, healthy, lean adults (25.8±3.2y; 22.7±1.9kg/m2; 3F; mean±SD) participated in a controlled 6-day in-laboratory protocol with 9h in bed (habitual sleep) followed by 4 nights of 5h in bed (insufficient sleep), achieved by delaying bedtime by 4 hours. For one week prior to the study, participants maintained a 9h sleep schedule. Participants consumed energy balanced diets 3 days prior to and throughout the laboratory protocol. Insulin sensitivity was assessed using a hyperinsulinemic euglycemic clamp before and after insufficient sleep. Skeletal muscle biopsies of the vastus lateralis were taken immediately before each clamp. In a subset of subjects (n=10), quantitative lipidomic analyses using LC/MS/MS were performed on biopsied muscle tissue.

Results
Insulin sensitivity was impaired following insufficient sleep (10.7±1.5 vs 9.6±1.2 mg/kg/min, p&lt;0.05, mean±SEM). There were no changes in skeletal muscle concentration of total triglycerides (TAGs), nor specific TAG species. However, insufficient sleep tended to increase skeletal muscle accumulation of total 1,2-DAGs (p=0.13) and significantly increased specific saturated species of 1,2-DAG, including Di-C18:0 DAG (p&lt;0.05), previously implicated in insulin resistance. In contrast, 1,3-DAGs are not thought to impair insulin sensitivity and specific species were decreased or unchanged during insufficient sleep.

Conclusion
Preliminary findings suggest that skeletal muscle lipid accumulation of diacylglycerol species during insufficient sleep may be a contributing mechanism by which insufficient sleep dysregulates metabolic physiology.

Support
NIH K01DK110138, R03 DK118309, UL1 TR002535, and GCRC RR-00036
0298 Sleep at Sea: A Qualitative Examination of Barriers to Sleep and Mitigation Strategies Among Shipboard Sailors
Authors: Schmied E A , Harrison E M , Dell’Acqua R , Glickman G L , Hurtado S L 
Published: May 2020

Abstract

Introduction
Sleep disturbance is prevalent among service members; however, little is known about factors that impede sleep in unique operational environments, such as aboard naval ships. Given the importance of sleep to health and performance, identifying both causes and potential solutions to sleep disturbance is critical. The objective of this qualitative study was to elucidate barriers to sleep and the strategies U.S. Navy sailors use to improve their sleep and combat fatigue while underway.

Methods
Interviews were conducted with 22 active duty service members assigned to sea duty. The semi-structured interview guide assessed the experiences of service members sleeping in shipboard environments, including the strategies used to improve sleep and combat fatigue. Interview transcripts were analyzed using applied thematic content analysis by two independent coders.

Results
Most participants were male (91.8%) and enlisted (95.5%). The most commonly reported barrier to sleep was stress (e.g., job-related stress), followed by rotating schedules, and environmental factors (e.g., noise, light). Many reported prioritizing other activities over sleep when off duty. Though only a few reported specific strategies to improve sleep while underway, strategies that were described primarily included mitigation of environmental barriers (e.g., noise-canceling headphones or sleep masks). However, some participants acknowledged these strategies are not always feasible (e.g., cost, reduced responsiveness to alarms or commands). Notably, few sailors reported using stress mitigation or relaxation strategies to help sleep. Caffeine intake was the only reported strategy for alerting when fatigued.

Conclusion
Sailors reported many barriers to sleep that are unique to the shipboard environment, yet most did not report using any mitigation strategies. Further, few used alerting techniques (other than caffeine) when fatigued. This at-risk population could benefit from targeted educational interventions covering sleep-promoting behaviors, prioritization of sleep, and fatigue mitigation.

Support
This work was supported by the Military Operational Medicine Research Program, Early Assessment and Intervention Working Group, under work unit no. N1702.
0307 Gray Matter Volume Correlates of Psychomotor Vigilance Speed During Sleep Deprivation
Authors: Meinhausen C E , Vanuk J R , Grandner M A , Killgore W D 
Published: May 2020

Abstract

Introduction
Sleep deprivation has often been associated with decreased cognitive control, including deficits in the ability to sustain attention. Psychomotor vigilance speed slows following a period of fatigue, and can lead to disastrous results in daily life. In order to determine the brain areas correlated with reduced psychomotor vigilance speed, as a result of diminished sleep, a voxel-based morphometry analysis was performed prior to a period of monitored sleep deprivation. The mean speed of response time during the final 17 hours of a 29-hour sleep deprivation was then measured with the Psychomotor Vigilance Test (PVT), a reaction-timed task that measures the speed participants respond to a visual stimulus.

Methods
45 healthy individuals (male=23 female=22) between the ages of 20-43 years (M=25.4 SD=5.6) participated in the study. Structural neuroimaging data were collected using a T3 magnetic resonance imaging scanner following a typical night’s sleep. Mean PVT speed was monitored with an hourly 10-minute PVT assessment during a monitored overnight sleep deprivation session. Speed was defined as the reciprocal of reaction time (1/RT).

Results
PVT speed was negatively correlated with grey matter volume (P&lt;.05 FWE-corrected) in the prefrontal cortex, specifically the right posterior inferior frontal gyrus (p=.030; MNI coordinates = 36, 12, 26).

Conclusion
Our findings indicate that gray matter within the right posterior inferior frontal gyrus is greater in individuals who are more vulnerable to slowing of PVT responses during an overnight period of sleep deprivation. These findings suggest that inter-individual differences in the ability to sustain psychomotor vigilance during sleep loss may be related to increased gray matter in the right lateral prefrontal cortex and could have implications for understanding the neurobiological substrates of vulnerability and resilience to sleep loss.

Support
0319 Sleep Architecture and Neurocognitive and Behavioral Functioning in Youth from the General Population
Authors: Ricci A , Fang J , He F , Cain P , Calhoun S L , Liao D , Vgontzas A N , Bixler E O , Fernandez-Mendoza J 
Published: May 2020

Abstract

Introduction
The transition from childhood to adolescence is critical for the onset of psychopathology and reflects significant changes in the sleeping brain. Sleep deprivation studies have shown that rapid eye movement (REM) and non-rapid eye movement (NREM) sleep are differentially involved in specific cognitive functions. The aim of this study was to examine the association of sleep architecture with neurobehavioral outcomes in a population-based sample.

Methods
We studied 700 children (5-12y, 47.1% female, 23.7% minority) and 421 adolescents (12-23y, 46.1% female, 21.8% minority) from the Penn State Child Cohort. All subjects underwent a 9-hour polysomnography and a 4-hour neurobehavioral evaluation. Neurocognitive outcomes included the Stroop test, digit span backwards (DSB), and coding to measure high- and low-order cognitive functions. Behavioral outcomes included the Child/Adult Behavior Checklist to measure internalizing symptoms and externalizing behaviors. Correlation analysis examined the cross-sectional association between sleep architecture and neurocognitive and behavioral outcomes.

Results
In childhood, %REM sleep was negatively associated with DSB scores (r=-0.088, p=0.027), particularly in males (r=-0.167, p=0.002). Furthermore, %NREM sleep was positively associated with DSB scores in males (r=0.126, p=0.021). In adolescent females, %NREM and %REM sleep were positively (r=0.146, p=0.044) and negatively (r=-0.158, p=0.029) associated with DSB scores, respectively. In adolescence, %NREM sleep was negatively associated with internalizing symptoms (r=-0.109, p=0.026).

Conclusion
Male children and female adolescents who spent a higher proportion of the night in NREM sleep had better working memory performance. Adolescent females who spent a lower proportion of the night in NREM sleep had greater internalizing symptoms. This study suggests a role for sleep architecture in neurobehavioral deficits in youth. Future studies are necessary to determine the contributions of low- and high-frequency sleep EEG dynamics to these clinical outcomes.

Support
National Institutes of Health (R01MH118308, R01HL97165, R01HL63772, UL1TR000127)
0330 Sleep Hygiene in Preschoolers: Assessing Biopsychosocial Factors Associated with Preschoolers’ Readiness to Learn
Authors: Messnick R , Evert L , Dixon B , Everse C , Manthei M , Rakus A , Trent-Brown S , Gall A J 
Published: May 2020

Abstract

Introduction
Sleep is crucial during early development to promote health, education, growth, and quality of life. Insufficient sleep is a public health problem, and this is clearly true for young children. The National Institutes of Health reported that preschoolers need 11-12 hours of sleep daily. We hypothesized that more physically active children would experience better sleep quality which would be associated with higher scores on cognitive and socioemotional measures. We also hypothesized that increased parental awareness of their child’s sleep patterns would predict more successful sleep health indicators in their children, leading to positive impact on preschoolers’ readiness to learn.

Methods
82 preschoolers (ages 3-5) completed memory tests, a sleep hygiene scale, and a socioemotional assessment. Following initial cognitive and socioemotional testing, Fitbit devices collected activity and sleep measures for 12 weeks. Additionally, parents recorded bedtimes, wake times, total sleep time, naps, and activity levels in daily sleep journals. We assessed the association between physical activity and sleep quality, bedtime, wake time, memory, sleep hygiene, and socioemotional measures.

Results
Physical activity was positively associated with better sleep habits, including earlier bedtimes, earlier wake times, more consistent sleep-wake patterns, socioemotional scores, and working memory capacity. Higher child and parent sleep hygiene scales were associated with more consistent bedtimes. On average, the 82 preschoolers tested fell short of the recommended 11-12 hours of sleep per night.

Conclusion
Greater child and parent awareness of practicing good sleep hygiene increased the likelihood for the child to practice better sleep habits. Since physical activity was positively associated with sleep health measures, it is critical that parents and teachers prioritize sleep and activity in young children. Results of this study provide greater knowledge regarding associations between sleep, physical activity, and biopsychosocial outcomes that may be useful in implementing better education for parents and children geared toward improving sleep.

Support
This research was generously supported by the Caplan Foundation for Early Childhood and the Hope College Psychology Department.
0339 Where Does the Time Go? Reported Activities Around the DLMO in Older Adolescents
Authors: Crowley S J , Janevski K , Eastman C I 
Published: May 2020

Abstract

Introduction
Older adolescents show heightened alertness in the evening close to the time of their Dim Light Melatonin Onset (DLMO), a time when the circadian system is most responsive to delaying light. We examined reported activities of adolescents around the time of their DLMO.

Methods
Forty-six adolescents (14.2-17.9 years; 24 females) who reported ≤7 h sleep on school nights and late bedtimes (school-night ≥ 23:00; non-school night ≥ midnight) slept at home on their usual school-year sleep schedule for 2 weeks. Participants reported their main activity via text message every hour from 16:00 until self-selected bedtime. After these 2 weeks, their DLMO was measured. We examined reported activities in the hour around the DLMO and the 2 hourly responses that followed on weeknights (Sunday-Thursday) to determine the most common activities (n=1380 responses). Logistic regression tested whether frequency of activities predicted whether a participant’s DLMO fell within the earliest (n=15; 19:31 ± 00:44), middle (n=16; 20:49 ± 00:20), or latest (n=15; 22:29±1:15) tertile.

Results
Overall, reported activities that consumed the most time were cell phone use (19.5%), homework (18.3%), and watching TV (15.1%). Adolescents who reported more homework, were more likely to have a DLMO in the middle tertile compared to the earliest and latest tertiles. Cell phone use was least likely in adolescents in the earliest DLMO tertile. TV watching did not predict DLMO group.

Conclusion
Adolescents who had the earliest DLMOs spent less time on their phones when light has the greatest delaying effect. These data may indicate that light from cell phone screens may delay circadian phase in this age group. Alternatively, cell phone use may be more likely if adolescents cannot fall asleep due to a later circadian cue for sleep onset.

Support
R01 HL112756 (Crowley)
0344 Age-Related Longitudinal Trajectories in NREM and REM Spectral Power
Authors: Gao C , Scullin M K 
Published: May 2020

Abstract

Introduction
Knowledge of how aging impacts sleep physiology is based almost exclusively on cross-sectional studies. Longitudinal studies, by contrast, can inform how macro- and micro-features of NREM and REM sleep change dynamically across time in individual trajectories. For the current work, we conducted quantitative EEG analyses from a longitudinal polysomnography study to inform age-related trajectories in sleep macro- and micro-architecture.

Methods
We conducted a secondary data analysis on 2208 participants in the Sleep Heart Health Study (mean age =62.47, SD=10.46, 55.30% females). Participants underwent one night of in-home polysomnography recording during two study visits (M=5.21 years apart, SD=0.53). Spectral power density was calculated for each 0.5 Hz frequency bin for NREM and REM sleep separately.

Results
In cross-sectional analyses, older chronological age was significantly associated with worse sleep macro-architecture. Plots of the individual trajectories over 5 years, however, revealed considerable inter-individual variability in whether sleep physiology was preserved or declined. Interestingly, there were strong associations between the longitudinal changes in power density in NREM and REM sleep (slow oscillations: r=.53 [.50-.56]; delta: r=.58 [.55-.60]; alpha: r=.69 [.67-.71]; sigma: r=.74 [.73-.76]; beta: r=.82 [.80-.83]; ps&lt;.001). The strongest NREM-REM association was for theta band power (r=.85 [.83-.86]), particularly in the 5.5-6.0 Hz bin (r=.94, [.94, .95]).

Conclusion
There is substantial inter-individual variability in how aging impacts sleep physiology. Nevertheless, within individuals, power density declines similarly across NREM and REM stages, with nearly perfect convergence for theta activity, indicating a common age-related neurobiological mechanism.

Support
The National Sleep Research Resource is supported by NIH HL114473.
0353 Objectively Measured Sleep and Components of Metabolic Syndrome in Well-Functioning Older Adults
Authors: Hossain S , Alfini A J , Wanigatunga A A , Rojo-Wissar D M , Schrack J A , Simonsick E M , Zipunnikov V , Wanigatunga S K , Spira A P 
Published: May 2020

Abstract

Introduction
Prior studies tying sleep to metabolic syndrome in older adults have mostly used self-report sleep measures. We investigated the association between actigraphic sleep parameters and metabolic syndrome components in well-functioning older adults.

Methods
We studied 434 participants in the Baltimore Longitudinal Study of Aging (aged 71.1±12.8 years, 41.4% women) with 6.6±1.0 nights of wrist actigraphy and data on metabolic syndrome components: blood triglyceride (TG) level &gt;150 mg/dL; high density lipoprotein (HDL) &lt;50 mg/dL; and waist circumference (WC) &gt;88.9 cm for women and &gt;101.6 cm for men. Sleep parameters were the primary predictors and metabolic syndrome components the outcomes. Logistic regression was performed, and results are expressed as odds ratio (OR) with p-values.

Results
After adjusting for age, sex, race and education, higher sleep efficiency (SEFF; per 10%) was associated with a lower odds of high WC (SEFF OR=0.60, p=0.01) and, compared to participants in the intermediate total sleep time tertile (5.5 to 6.8 h), those in the shortest tertile (&lt;5.5 h) had a slightly lower odds of high WC (TST OR=0.98, p=0.02). In adjusted models, greater wake after sleep onset (WASO; per 30 min), greater average wake bout length (WBL; per min), and lower SEFF (per 10%) were associated with a greater odds of poor HDL level (&lt;50 mg/dL) (WASO OR=1.37, p=0.05; WBL OR=1.49, p=0.007; SEFF OR=0.72, p=0.04). After further adjustment for BMI and depressive symptoms, only the association between longer WBL and poor HDL level remained significant (OR=1.48, p=0.01). There were no associations between sleep parameters and TG level.

Conclusion
Among well-functioning older adults, greater WASO but lower TST and SE are associated with poorer metabolic syndrome components. Longitudinal research is needed to evaluate the temporal associations of objectively measured poor sleep and metabolic syndrome components and evaluate the roles of BMI and depressive symptoms in these associations.

Support
The first author is supported by a Postdoctoral Fellowship by the Intramural Research Program (IRP) at the National Institute on Aging (NIA). This study was supported in part by National Institute on Aging (NIA) grant R01AG050507, the NIA Intramural Research Program (IRP), and Research and Development Contract HHSN-260-2004-00012C.