bluuebunny/crossref_metadata_2025 huggingface dataset:
0257 Preliminary Findings: Attentional Bias for Food Cues Unrelated to Time Awake or Circadian Phase During Forced Desynchrony in Adolescents
Authors: Wong P M , Barker D H , Raynor H A , Hart C , Carskadon M A
Published: May 2020

Introduction

Sleep quantity and quality influence attentional bias, and attentional bias for food cues has been associated with body weight. Whether the endogenous circadian cycle and/or time from awakening to bedtime contribute to attentional bias for food and differences in weight remain unclear. Using a 28-h forced desynchrony (FD) design, we hypothesized that adolescents with overweight (OW) and obesity (O) would have more attentional bias for food cues later in the wake episode and at a later circadian phase compared to adolescents with a healthy weight (HW).

Methods

50 (28 male) adolescents (12-15yr) completed 7 FD cycles. Participants completed an attentional bias task that included three food word categories (savory, sweet, fruits/vegetables) and one non-food word category (school supplies). The task was completed at 6 fixed times each cycle: Task 1 was 1.3h after scheduled awaking, Task 2 was 2h after Task 1, and Tasks 3–6 followed at 3-h intervals. Weight categorization used body mass index (BMI) percentiles (CDC): HW (>5th and <85th; n=24), OW (85th and <95th; n=13), or O (≥95th; n=14). Endogenous circadian period was determined using salivary melatonin onsets (Mean: HW=23.88h; OW=24.01h; O=23.86h). Effect of circadian phase and time since scheduled awakening was assessed by mixed effects modeling using 6 circadian and 6 time-awake bins.

Results

We found no significant differences between weight groups in attentional bias for any of the food categories (p’s >.05). We also saw no significant time awake effects or circadian influence on attentional bias, nor did time awake or circadian phase moderate the associations between weight category and attentional bias (p’s >.05).

Conclusion

Weight groups did not impact food-related attentional bias across the wake episode or circadian phase. Future directions will explore whether attentional bias for food types predicts food choice and food consumption in this study.

Support

DK101046
0260 Association Between Free-Living Physical Activity and Sleep in Icelandic Adolescents
Authors: Rognvaldsdottir V , Johannsson E , Soffia H M , Stefansdottir R S , Arngrimsson S A , Cheng K Y , Brychta R , Gudmundsdottir S L
Published: May 2020

Introduction

Sleep and physical activity are both important to health, but the demands of our modern schedule often require individuals to choose one over the other. In adolescents, the association between objectively measured sleep and physical activity is not well established in the literature. The aim of current study was to assess associations between free-living and physical activity and sleep among 15-year-old adolescents.

Methods

Free-living physical activity and sleep were assessed with wrist-worn accelerometers, sleep diary, and questionnaires during a 7-day period including school days and non-school days in 270 (161 girls) adolescents (mean age 15.8±0.3y) in Reykjavik, Iceland. Linear regression analysis was used to explore the associations between objectively measured physical activity and sleep. T-test was used to determine if there is a significant difference in objectively measured sleep between those who reported sports or exercising <6 versus ≥6 h/week.

Results

Weekly mean physical activity (2040±466 counts/min of wear/day) was negatively associated with total sleep time (6.6±0.64 h/night) (β±SE=-3.5±0.7, p<0.001). However, physical activity was also negatively associated with minutes of wake after sleep onset on non-school days (p=0.047) and standard deviation (i.e. night-to-night variability) of total sleep time over the week (p=0.028). Subjects who reported exercising ≥6 h/week (n=116) had lower night-to-night variability in bedtime (41.2±27.9 min) than those who did not (49.8±37.5 min), p=0.033.

Conclusion

The negative association between physical activity and sleep duration suggests that in more active individuals’ physical activity may be displacing sleep. However, greater physical activity is also associated with fewer minutes of awakening and a less variable sleep schedule, indicating better sleep quality. These findings suggest that physical activity is important for good sleep quality, but students should more closely consider sleep guidelines when designing an exercise schedule. Future studies should test how change in sleep patterns might influence physical activity.

Support

Icelandic Centre for Research, National Institute of Diabetes and Digestive and Kidney Diseases.
0261 A Randomized Trial on The Effects of Standard and Flexible Duty-Hour Rules on Intern Sleep and Alertness
Authors: Dinges D F , Asch D A , Shea J A , Bellini L M , Carlin M , Malone S K , Desai S V , Sternberg A L , Tonascia J , Katz J T , Silber J H , Volpp K G , Mott C G , Mollicone D J , Basner M
Published: May 2020

Introduction

Duty hour regulations affect resident sleep, education, and patient care in complex ways. We performed a national cluster-randomized trial (iCOMPARE) in 63 internal medicine residency programs comparing the effects of the 2011 duty-hour standards to a more flexible set of duty hour rules characterized by maintaining an 80-hour workweek but without limits on shift length or mandatory time off between shifts, relative to patient mortality, intern educational outcomes, and intern sleep and alertness.

Methods

In the sleep and alertness sub-study, sleep duration and morning sleepiness and alertness were assessed with actigraphy, the Karolinska Sleepiness Scale, and a 3-minute Psychomotor Vigilance Test (PVT-B) for 14 days in 193 interns from 6 standard programs and 205 interns from 6 flexible programs.

Results

During the 14-day study periods, interns in standard and flexible programs averaged 7.03h sleep/24h (95% confidence interval [CI] 6.78h, 7.27h) and 6.85h sleep/24h (95% CI 6.61h, 7.10h), respectively. Sleep duration (difference between arms of -0.17h/24h; 1-sided lower 95% confidence limit -0.45h; NIM -0.5h; P=0.02 for noninferiority) and KSS sleepiness (difference 0.12 points; 1-sided upper 95% confidence limit 0.31 points; NIM 1 point; P<0.001) were noninferior in flexible versus standard programs. We could not establish noninferiority for PVT-B alertness (difference -0.3 lapses; 1-sided upper 95% confidence limit 1.6 lapses; NIM 1 lapse; P=0.10). Based on analyses by shift type, sleep duration was 1.77h shorter on days when interns in flexible programs finished an overnight shift relative to a regular day shift (p<.001), with significant decreases in subjective and objective alertness, and frequent reports of excessive sleepiness, especially between 12am and 6am.

Conclusion

There were no signs of relevant chronic sleep loss across shifts in interns in flexible programs relative to their standard program counterparts. Interns were able to compensate for the sleep lost during extended overnight shifts by increasing sleep duration on nights prior to day shifts, night shifts, and days off. Increased sleepiness and reduced alertness of interns following extended overnight shifts need to be mitigated and suggest a role for fatigue-risk management programs.

Support

Supported by NHLBI grants U01HL125388 and U01HL126088 and grants from the ACGME.
0265 Cortisol and C-Reactive Protein Fail to Predict Individual Differences in Neurobehavioral Performance Responses to Total Sleep Deprivation and Psychological Stress
Authors: Goel N , Yamazaki E M , MacMullen L E , Ecker A J
Published: May 2020

Introduction

Individuals show marked differential vulnerability in neurobehavioral deficits from psychosocial stress and sleep deprivation. Although changes in salivary cortisol and C-reactive protein (CRP) typically occur across total sleep deprivation (TSD) and recovery sleep, whether these biological markers during fully rested conditions predict individual differences in cognitive performance during TSD and stress remains unknown.

Methods

Thirty-one healthy adults (ages 27–53; mean ± SD, 35.4 ± 7.1y; 14 females) participated in a five-day experiment consisting of two 8h time-in-bed (TIB) baseline nights, followed by 39h TSD, and two 8h-10h TIB recovery nights. A modified Trier Social Stress Test (TSST) was conducted on the day of TSD to induce psychological stress. Salivary cortisol and CRP from blood were obtained at six time points during the study (pre-study, baseline, during TSD, during TSD after the TSST, after recovery, and post-study). A median split of TSD performance [total lapses (>500 ms response time) and errors] on the 10-minute Psychomotor Vigilance Test (PVT) defined cognitively resilient (n=15) and cognitively vulnerable (n=16) groups. Repeated measures ANOVA and post-hoc comparisons corrected for multiple testing, examined cortisol and CRP across time points between groups.

Results

In both cognitively resilient and vulnerable individuals, cortisol increased with TSD compared to baseline in the morning and decreased with TSD + psychological stress in the afternoon compared to TSD alone. By contrast, there were no significant changes in CRP levels throughout the experiment. In addition, there were no significant time*group interactions in cortisol or CRP levels.

Conclusion

Salivary cortisol increased with TSD compared to baseline and showed a time-of-day effect with stress during TSD. Notably, cortisol and CRP did not differ between cognitively resilient and vulnerable individuals across TSD, psychological stress or recovery sleep and thus are not reliable biomarkers for predicting performance under these conditions.

Support

NASA NNX14AN49G.
0279 Fatigue and Pain Responses Across Repeated Exposure to Experimentally Induced Sleep Disturbance and Intermittent Recovery Sleep: Sex Differences
Authors: Goldstein M R , Simpson N S , Devine J K , Dang R , Connors C , Engert L C , Chatterton B , Scott-Sutherland J , Yang H , Mullington J M , Haack M
Published: May 2020

Introduction

Sleep disturbances are more common in women than in men, as are many chronic pain disorders characterized by inflammation and fatigue. This study investigated sex differences in fatigue and pain responses to sleep disruption and whether such responses recover with uninterrupted sleep.

Methods

24 healthy young individuals (12 women; ages 18–42 yrs) participated in a study consisting of two counterbalanced 19-day experimental in-hospital stays, separated by two months. Following 3 baseline nights, participants were exposed to 3 nights of sleep disruption (SD) involving delayed sleep onset, hourly awakenings, and early-morning awakenings without return to sleep, followed by 1 night of recovery sleep. This 4-day cycle was repeated three times and finished with 3 additional nights of recovery sleep. Total sleep opportunity on SD nights was 4 hrs, and on recovery/sleep control (SC) nights was 8 hrs. Light exposure, ambient temperature, food and fluid intake, and physical activity were controlled. Self-reported fatigue and pain, pain sensitivity, and habituation were collected throughout. Data were analyzed with linear mixed models.

Results

For women but not men, fatigue in response to SD recovered incompletely starting after the 2nd sleep disruption-recovery cycle and remained elevated after the final 3 recovery nights in women (p<.05). Additionally, women became more sensitive to pressure pain in response to SD (p<.001) with incomplete return to baseline after the final 3 recovery nights. Whereas men habituated to cold pain across SC and even more so across SD (p=.045 Day, p=.021), women did not habituate.

Conclusion

These results indicate that incomplete recovery in both fatigue and pressure pain, alongside a lack of habituation to cold pain, in response to sleep disruption may explain the common co-occurrence of insomnia, fatigue, and pain observed as more prevalent in women.

Support

NIH/NINDS R01-NS091177; NIH/National Center for Research Resources UL1-RR02758 and M01-RR01032 to the Harvard Clinical and Translational Science Center.
0282 Correlation Between Sleep Depth in the Right and Left Cerebral Hemispheres Following Sleep Deprivation, Restriction or Noise Exposure
Authors: Younes M , Kuna S T , Pack A I , Schweitzer P K , Walsh J K , Smith M G , Basner M , Aeschbach D
Published: May 2020

Introduction

The Odds-Ratio-Product (ORP) is a highly-validated continuous index of sleep depth (range 0=deep sleep; 2.5=full wakefulness). ORP values fluctuate within this range as sleep state changes between wake and different sleep stages. In healthy non-sleep deprived adults, intra-class correlation coefficient of concurrent right vs. left ORP values (R / L coefficient) is typically >0.80. In a recent study R / L coefficient was markedly reduced in many critically-ill patients and these patients failed to be weaned from mechanical ventilation. Given the high prevalence of sleep loss in such patients we hypothesized that reduction in R/L coefficient might result from sleep loss. This retrospective EEG analysis of data from 3 independent research studies investigated if R / L coefficient decreases in pure models of sleep deprivation, restriction or noise exposure during sleep in healthy subjects.

Methods

Polysomnograms were obtained from three studies: A) 200 subjects who underwent 36 hours of total sleep deprivation; B) 21 subjects who underwent 4 consecutive nights of sleep restriction (5 hrs. / night); C) 72 subjects who were exposed to intermittent traffic noise events with maximum sound pressure levels ranging from 45–65 dB(A) for 10 consecutive nights. For study A, R / L coefficient was calculated from pre- and post-deprivation sleep studies and the two values were compared. For study B, coefficient was calculated at baseline and in each restriction night. For study C, the coefficient was calculated in each of the 10 exposure nights and the slope of the change was calculated.

Results

In study A, the coefficient decreased from 0.82±0.12 at baseline to 0.74±0.16 after sleep deprivation (p < 0.0001). In study B, the coefficient decreased from 0.83±0.11 at baseline to 0.75±0.15 on the 4th restriction night (p < 0.01). In study C, coefficient decreased at a rate of 0.003±0.001 per exposure night (p < 0.001).

Conclusion

The correlation between sleep depth in the right and left hemispheres deteriorates following sleep deprivation, restriction or noise-induced sleep fragmentation.

Support

NIH P50 HL060287
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

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<0.001), an interaction between GROUP and PHASE (F=12.95, p<0.001) and an interaction between VUL, GROUP, and PHASE (F=8.04, p<.01). Resolving this 3-way interaction for ACUTE revealed a main effect of VUL (F=9.34, p<.005), a main effect of GROUP (F=5.96, p<.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<0.01)). Resolving the 3-way interaction for CHRONIC revealed a main effect of GROUP (F=8.95, p<0.01), no significant of VUL (F=3.36, p=0.077) and an interaction between VUL and GROUP (F=6.11, p<0.05). Resolving this interaction showed that only for the LOWVUL participants in CAF, the slope was higher than PL (p<.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

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 > .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 > .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

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<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<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

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

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<.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

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

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

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

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<.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

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 >150 mg/dL; high density lipoprotein (HDL) <50 mg/dL; and waist circumference (WC) >88.9 cm for women and >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 (<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 (<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.
0359 The Moderating Role of Race in the Association of Adolescent Sleep Duration and Marijuana Use
Authors: Levenson J C , Atuahene B , Bear T , Hacker K , Ricci E , Goldstein T R , Miller E
Published: May 2020

Introduction

Insufficient sleep and marijuana use during adolescence vary by race and are associated with poor outcomes in various domains. Sleep difficulties predict drug-related problems, but not all adolescents with insufficient sleep go on to use substances. We examined whether race/ethnicity moderates the association of sleep duration and marijuana use among Black/African-American and White adolescents using a countywide probability-based survey of adolescents.

Methods

Using cross-sectional data (n=1447), logistic regression examined whether race moderated the association of adolescent sleep duration and recent marijuana use alone and after controlling for covariates in both weighted and unweighted models.

Results

Hours of sleep was significantly negatively associated with recent marijuana use. Black/African-American youth in our sample had up to a 60% increased odds of marijuana use in the past 30 days compared to White youth, and they reported significantly shorter sleep duration than their White peers. In weighted models, Black/African-American youth had an increased probability of marijuana use with fewer hours of sleep as compared to White youth, even after accounting for covariates.

Conclusion

In our countywide survey of adolescents, we found racial differences in the association of sleep duration and marijuana use. Future work should replicate our analyses with a longitudinal sample of adolescents to better evaluate the direction of these effects. Future efforts should also focus on identifying contextual factors that may explain racial differences in the sleep duration—substance use relationship, as well as developing strategies to reduce disparities in this relationship.

Support

The Heinz Foundation, the Hillman Foundation, the Grable Foundation, and the FISA Foundation. Dr. Levenson’s effort was supported by NICHD.
0382 Sex Differences in Sleep and Quality of Life in Healthcare Shift Workers
Authors: Lammers-van der Holst H M , Zhang Y , Barger L K , Wise J C , Murphy A S , Desnoyers B M , Qadri S , Ronda J M , Duffy J F
Published: May 2020

Introduction

Shift work is associated with insufficient and disrupted sleep and impaired quality of life due to misalignment between the timing of internal biological clock and work/sleep schedule. There are reported sex differences in the circadian timing system, in sleep, and in reported sleep complaints, but how these impact female shift workers remains unclear. Furthermore, relatively little is known about sex differences in quality of life in shift workers. The objective of this study is to investigate sex differences in sleepiness, insomnia and quality of life in healthcare shift workers.

Methods

Forty women (31 ± 6.4 yo) and 70 men (31.2 ± 6.7 yo) who work at least 4 night shifts a month, completed the Shift Worker Sleep and Health Survey. This REDcap administered survey included the Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and Functional Outcomes of Sleep Questionnaire (FOSQ-10). Independent samples T-tests were carried out using SAS.

Results

Women reported significantly higher scores on the ESS compared to men (13 ± 4 vs. 11 ± 3.4, respectively; t(108)=-2.74,P=0.007), as on the ISI (13 ± 5.2 vs. 9.8 ± 5.4; t(108)=-3.05,P=0.003), indicating greater levels of daytime sleepiness and insomnia-like symptoms in female shift workers. In addition, women scored significantly lower on the FOSQ-10 than men (13.9 ± 2.9 vs. 15.3 ± 2.5; t(108)=2.68,P=0.009), suggesting a lower functional status related to activities of daily living in female shift workers.

Conclusion

These preliminary analyses suggest that in this group of healthcare shift workers, women are less tolerant to irregular work hours compared to men, in terms of sleep, sleepiness and quality of life. Our future goal is to understand how sleep quality and duration, daytime sleepiness, and quality of life interact, and what role sex plays in those interactions.

Support

The study was supported by NIH grant R01 AG044416.
0387 Effect of Air Pollution on the Quality of Sleep - Korean Nationwide Cross-Sectional Study
Authors: Hong S
Published: May 2020

Introduction

Poor sleep quality is associated with adverse health outcomes, such as cardiovascular disease, diabetes and obesity. Several studies have indicated the association between exposure to air pollution and sleep quality. However, the evidence is very limited in South Korea.

Methods

We conducted a cross-sectional study using data from a nationwide sample of 165,193 individuals aged 19 years or older from the 2018 Korea Community Health Survey. Perceived air pollution was measured in the baseline survey. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was defined by the global score of PSQI > 5. The associations between perceived air pollution and sleep quality were examined using the regression models. Additionally, the average concentration of PM2.5 was measured in each region using a satellite-based prediction to see the association between perceived air pollution and long term exposure of fine dust.

Results

After adjusted for age, education, and income, the adjusted odds ratios (95% confidence interval) of poor sleep quality associated with perceived air pollution was 1.45. The average of daily concentrations of PM2.5 over 3 years was highest in Incheon area, followed by Seoul and Busan city. Among Gyeonggi Province, the most populous region in South Korea, the PM2.5 concentrations was the highest in Ansan. In each region in Korea, Incheon had the highest poor sleep quality rate of 48.0%, while Ansan in Gyeonggi Province had the highest rate of 61.5%. The results are in line with the distribution of PM2.5 concentrations by region.

Conclusion

Perceived air pollution and long term exposure of fine dust were associated with poor sleep quality in South Korea. Improvement of air quality may help to improve sleep quality. More studies are in need in the future to explore the biological mechanism for the relationship, and to also examine such relationship among different populations and in difference environments.

Support

For this study, we used raw data from the 2018 Korea Community Health Survey (KCHS), conducted by the Korea Centers for Disease Control and Prevention
0389 Prevalent Insomnia Symptoms and Need for an Intervention Among Oncology Nurses
Authors: Lee S , Vigoureux T F , Gonzalez B D , Small B J
Published: May 2020

Introduction

Insomnia is prevalent in the working population. Nurses may be particularly vulnerable to insomnia due to demands with shift work, limited recovery between shifts, lack of control over their work, and stress associated with proximity to life-threatening health conditions. Insomnia in nurses is a significant public health burden, because it can lead to degraded quality of patient care. This study examined the prevalence of insomnia symptoms among oncology nurses and the need for an intervention to improve insomnia symptoms.

Methods

Participants were 62 nurses working full-time at a cancer hospital (Mage=35.26±11.69). Participants were asked about their (1) main sleep-related complaint, (2) willingness to participate in a sleep-focused intervention, (3) preferred delivery forms of the intervention (i.e., group-based, online, and/or one-on-one), and (4) preference for content to include in the intervention (e.g., sleep hygiene education, mindfulness, cognitive-behavioral therapy). We used content analysis to analyze open-ended responses as well as descriptive statistics to summarize data.

Results

Most (74%) reported difficulty falling or staying asleep or not feeling rested upon awakening as their primary or secondary sleep concerns. Nearly all nurses (95%) expressed interest in participating in a future sleep-focused intervention. In terms of preferred delivery forms of the intervention, an online intervention was most preferred (56%), followed by group meetings at the workplace (50%), and one-on-one meetings at the clinic (29%). Mindfulness strategies were preferred by most nurses (73%), followed by cognitive-behavioral therapy (48%), and sleep hygiene education (34%).

Conclusion

Most oncology nurses report insomnia symptoms and the majority are interested in participating in an intervention to improve their insomnia symptoms either online or in group sessions at the workplace. The information obtained from this pilot study will serve as the basis for developing a future intervention to improve insomnia and overall sleep health in oncology nurses.

Support

This work was supported, in part, by the University of South Florida College of Behavioral & Community Sciences Internal Grant Program (PI: Lee, Grant No. 0134930).