bluuebunny/crossref_metadata_2025 huggingface dataset:
0132 Effects of Sleep Behavior, Obesity, and Sex on Well-Being and Mental Health Problems in Adolescents
Authors: Harkness Anya , Perez-Amparan Evelyn , Camacho Leticia , Fan Ruby , Kerr Erin , Arra Nicole , Durley Ingrid , Tager Lucas , Bland-Boyd Brittany , Müller-Oehring Eva , Nagata Jason , Baker Fiona , Kiss Orsolya
Published: April 2024

Introduction

Poor sleep and mental health problems commonly emerge in adolescence, with a higher prevalence in females and those who suffer from obesity. Here, we evaluated the complex associations between poor sleep, obesity, and biological sex and how they interact to influence wellbeing in a large, diverse cohort of adolescents in the US.

Methods

Data were analyzed from 7,261 adolescents (Year 2: Mean age=11.94 years, range: 10-14 years, 47.3% female), collected as part of the ongoing ABCD Study®. Sleep duration was assessed with the Munich Chronotype questionnaire (youth-report), and sleep quality was assessed with a question about having trouble falling or staying asleep in the past two weeks from the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS-5) (youth-report). Internalizing and externalizing problems were assessed using the Child Behavior Checklist (caregiver-report). Positive affect was assessed with the NIH-toolbox measures. Regression models examined associations between obesity (>95 body mass index percentile), sleep behavior and mental health, considering sex differences, age, and socio-demographic characteristics.

Results

Short sleep duration and poorer sleep quality, as well as obesity were associated with higher internalizing (p<.01) and externalizing (p<.01) problems. Adolescents with obesity and prolonged sleep duration had higher internalizing (p=.01) and externalizing problems (p<.01). Shorter sleep duration (p<.01) and poorer sleep quality (p=.01) were associated with lower positive affect, with stronger effects in female adolescents. Obesity partially mediated the association between sleep problems and positive affect (p<.01).

Conclusion

This study demonstrates a strong link between sleep, obesity, and mental health outcomes in adolescents, highlighting significant sex differences. Poor sleep quality and obesity is related to more internalizing and externalizing problems and lower positive affect, with notable with notable impacts on female adolescents. These findings highlight the importance of addressing sleep and obesity in adolescent mental health interventions, recognizing the unique vulnerabilities and needs of male and female adolescents and those with obesity.

Support (if any)

National Institutes of Health: U01DA041022
0133 The Impact of Stress and Sleep: Capturing Multiday Patterns
Authors: Amin Ohida Binte , Mishra Varun , Sathyanarayana Aarti
Published: April 2024

Introduction

Students commonly experience stress due to constant academic demands and societal pressures. This study aims to investigate whether there are differences in sleep efficiency among students experiencing high, low, and medium levels of stress. We performed statistical analyses on sleep efficiency across various stress levels to investigate how stress affects daily sleep patterns.

Methods

Using the GLOBEM dataset, we computed the range of daily sleep efficiency scores for individual students, considering their highest and lowest sleep efficiency levels observed throughout the study. We classified days into high, medium, and low-stress categories based on students’ weekly Perceived Stress Scale 4 (PSS-4) survey scores. We focused on sleep efficiency ranges within each stress group, emphasizing the significance of considering variability alongside average values to uncover distinct sleep patterns. A one-way analysis of variance (ANOVA) was employed to examine variations in sleep efficiency ranges among different stress groups. Subsequently, Tukey's post hoc analysis was conducted to identify specific groups that exhibited differences in their sleep efficiency.

Results

No statistically significant differences were observed in daily sleep efficiency scores among students with high, medium, and low stress levels. However, we identified significant variations in sleep efficiency ranges (ANOVA F(2) = 18.14, p < 0.0000001). Post-hoc Tukey analysis revealed mean differences, indicating a significant increase in sleep efficiency ranges between high and low-stress groups (p = 0.0) and a significant increase between high and medium-stress groups (p = 0.0). Notably, no statistically significant difference was found between the low and medium-stress groups. The instances of high-stressed days (N=140), medium-stressed days (N=2271), and low-stressed days (N=1615) provide context to these findings highlighting variations in sleep efficiency.

Conclusion

A significant correlation between stress severity and sleep efficiency does not exist at the day level. However, when we looked at variations in sleep efficiency over time, there are statistical significant differences that correlate with stress severity. The increase in sleep efficiency ranges among high-stress students indicates that they don’t consistently experience poor sleep efficiency but rather exhibit more erratic sleep patterns. This underscores the importance of considering stress severity when analyzing and addressing sleep patterns in students.

Support (if any)
0134 Diurnal Patterns in Social Belonging and Perceived Burdensomeness Among Young Adults
Authors: Tubbs Andrew , Gorovoy Suzanne , Fernandez Fabian-Xosé , Perlis Michael , Grandner Michael
Published: April 2024

Introduction

Suicide is the second-leading cause of death among young adults. Feelings of thwarted belongingness and perceived burdensomeness may accompany or precipitate suicidal thoughts. It is unclear how these negative cognitions vary across the day.

Methods

Individuals aged 18-25 (N=143) participated in a week-long ecological momentary assessment study of sleep (measured by daily sleep diaries) and feelings of social belonging and perceived burdensomeness (measured by text message surveys sent five times per day). Each dimension was assessed by three questions with ratings from 1 (not true at all for me) to 7 (very true for me). Text surveys were scheduled across the day (roughly at 2AM, 7AM, 12PM, 5PM and 10PM), and responses were categorized by whether the individual reported suicidal ideation at that time or not.

Results

A total of N=3442 text surveys were collected from N=134 participants. Participants provided an average of 26 of 35 possible surveys (SD=8.3). Non-ideators reported consistently elevated feelings of social belonging (5.41 out of 7, SD=1.71) and consistently low feelings of perceived burdensomeness (1.54 out of 7, SD=1.13). Suicidal ideators, however, reported generally low social belonging (2.8 out of 7, SD=1.84) and elevated perceived burdensomeness (4.31 out of 7, SD=1.99). Two-way ANOVAs found that social belonging varied significantly by suicidal ideation (p < 0.001) and marginally for time by suicidal ideation (p = 0.069). Perceived burdensomeness varied only by suicidal ideation (p < 0.001); there was no significant interaction of time by suicidal ideation.

Conclusion

Feelings of social belonging and perceived burdensomeness varied substantially only for individuals experiencing suicidal ideation, and only marginally over time among suicidal ideators. Additional work is needed to determine how sleep continuity and regularity may influence these findings.

Support (if any)
0135 Association of Circadian Misalignment with Internalizing Symptoms and Externalizing Behaviors in Adolescents
Authors: Ballester-Navarro Pura , Morales-Ghinaglia Natasha , Calhoun Susan , Liao Jason , Vgontzas Alexandros , Liao Duanping , Bixler Edward , Fernandez-Mendoza Julio
Published: April 2024

Introduction

Biological changes during adolescence naturally delay the circadian sleep-wake cycle. Adolescents struggle between the imposed timing of their sleep-wake cycle by social demands and their desired one, resulting in circadian misalignment. Circadian misalignment has been associated with a higher risk for mental health problems. We examined whether objective and subjective metrics of circadian misalignment are associated with internalizing symptoms (IS) and externalizing behaviors (EB) in adolescents.

Methods

We studied 376 adolescents from the Penn State Child Cohort (median 16 years; 47% female; 21% racial/ethnic minority) who had a minimum of 3-nights of at-home actigraphy (ACT), and 9-h in-lab polysomnography (PSG). ACT-measured sleep midpoint (SM) was calculated as the central point of the sleep period, while sleep regularity (SR) was calculated as the intra-individual standard deviation of the SM. Circadian preference (CP) was measured with the Morningness-Eveningness Questionnaire. IS and EB were measured by parent- or self-report on Achenbach System of Empirically Based Assessment using developmentally-appropriate forms and norms. Stepwise linear regression models adjusted for demographics (sex, race/ethnicity, age, BMI percentile), sleep disorders (insomnia, PSG-apnea/hypopnea index) and insufficient sleep (ACT-mean sleep duration, ACT-sleep duration variability).

Results

Both CP (r=-.118, p=.022) and SR (r=.116, p=.024) were associated with IS, however, they competed between each other in regression models resulting in marginally significant associations (β=-.094, p=.079 and β=.092, p=.084, respectively) that were further attenuated after adjusting individually for covariables (β=-.072, p=.190 and β=.076, p=.163, respectively). Both CP (r=-.230, p<.001) and SR (r=.140, p=.006) were associated with EB; however, only CP (β=-.153, p=.004) remained significantly associated with EB after adjusting for covariables (β=-.130, p=.016).

Conclusion

Assessing self-reported eveningness is a useful and inexpensive tool to identify adolescents in whom circadian misalignment contributes to mood and behavioral problems. However, it appears that its combination with objective assessments, particularly irregularity of the sleep-wake cycle, may yield the most predictive results.

Support (if any)

NIH R01HL136587, R01MH118308, UL1TR000127
0138 Effects of Slow Oscillation Enhancement During NREM Sleep Using Closed-loop Auditory Stimulation on Anxiety
Authors: Suzuki Yoko , Ding Ning , Sato Kazuki , Wang Zishan , Suzuki Yurina , Oiwa Yumeka , Kanbayashi Takashi , Abe Takashi
Published: April 2024

Introduction

Sleep is associated with emotions. Recently, some evidences demonstrated that longer slow-wave sleep (SWS) or higher slow-wave activity (SWA) is associated with the greater anxiety reduction, which is an emotion (Horvath et al., 2015; Ben Simon et al., 2020). Slow oscillations (SOs) (< 1 Hz), which are mainly observed during SWS, are essential hallmarks of SWS. We hypothesized that enhancing SOs and SWA during non-rapid eye movement (NREM) sleep could reduce anxiety in highly anxious individuals. A previous study established non-invasive closed-loop auditory stimulation (CLAS) to enhance SOs during NREM sleep (Ngo et al., 2013); furthermore, CLAS increases SWA (Krugliakova et al., 2020). The present study aimed to investigate whether CLAS during NREM sleep to enhance SOs could reduce anxiety in healthy, highly anxious adults.

Methods

Sixteen healthy adults (23.9±3.7 years, six women) with trait-anxiety scores of 45–80 on the state-trait anxiety inventory (STAI) were included. A single-blind crossover test was conducted with two conditions; the SOs were tracked from the electroencephalography (EEG) and sounds were presented by CLAS (STIM) and the SOs were tracked but no sounds were presented (SHAM). On each experimental day, the participant was attached a polysomnograph and additional EEG for CLAS, which analyzes the EEG in real-time. Participants completed questionnaires, which included state-anxiety scores from the STAI, Profile of Mood States Second Edition (POMS2), and Positive and Negative Affect Scale (PANAS). Participants slept for 8 h, and once awakened, they completed the same questionnaires before sleeping.

Results

There was no difference in STAI scores and POMS2 and PANAS between the two conditions (STIM or SHAM).

Conclusion

Contrary to the hypothesis, SOs enhancement during NREM sleep by CLAS did not relieve anxiety. It may be due to the small effect of CLAS on anxiety for a one-night study in healthy young adults. Eventually, we should investigate whether CLAS intervention over multiple nights improves anxiety.

Support (if any)

This work was supported by the JSPS KAKENHI grant numbers JP19K16243 and JP23K14436.
0139 Testing the Mood Regulatory Hypothesis of Dreaming
Authors: Baber Garrett , Jun Daiil , Girard Jeffrey , Gratton Matthew , Hamilton Nancy
Published: April 2024

Introduction

Dreaming has been theorized to facilitate fear extinction learning in a manner akin to desensitization therapy. A testable hypothesis from this theory is that the experience of fear in dreams leads to lower subsequent daytime negative affect. This study employed a novel natural language processing tool and multilevel modeling to test whether fear in dreams led to reductions in negative affective the next day.

Methods

Data from 553 participants (4986 observations) were analyzed from a larger online daily survey study of sleep and mental health from Boston College. Participants completed multiple days of dream reports and measures of daytime negative affect and sleep efficiency. Dream fear was estimated using a novel deep learning natural language processing model trained on fear-annotated tweets, applied to participants' dream report text. We fitted a Bayesian zero-inflated negative binomial multilevel model to estimate within- and between-person effects of dream fear on next-day negative affect while controlling for sleep efficiency, dream report word count, the difference between time of survey completion and time awake, total number of dreams per subject, and neuroticism.

Results

The analysis revealed that days with higher dream fear within individuals were associated with higher next-day negative affect, controlling for other variables. Specifically, for each standardized increase in dream fear, a 14% increase in next-day negative affect was predicted, surpassing the effect of poor sleep efficiency (6% increase). Moreover, individuals consistently reporting higher average dream fear tended to exhibit higher average negative affect (12%).

Conclusion

Contrary to the proposed hypothesis that dream fear regulates daytime mood, we found that fearful dreams may lead to lower next-day mood. Nights higher in dream fear were associated with increased next-day negative affect for that person, independent of sleep efficiency and neuroticism. Notably, dream fear appeared to contribute more than twice as much as poor sleep efficiency to heightened negative affect. Leveraging advanced natural language processing and multilevel modeling, this research increases our understanding of the ways dream experiences affect waking life by showing that fearful dreams may be an important day-to-day predictor of mood. Future work should explore dynamic relationships between dream emotions and mood.

Support (if any)
0141 Nighttime Napping Dampens Daily Peak of Sleepiness in Simulated Night Shift Schedules with Restricted Daytime Sleep
Authors: Muck Rachael , Jones Christopher , Basner Mathias , Dinges David , Van Dongen Hans
Published: April 2024

Introduction

Night shift workers experience increased sleepiness during the night due to increasing homeostatic sleep drive and reduced circadian wake drive, and because their daytime sleep is typically restricted. Nighttime napping is a countermeasure to sleepiness, but the effectiveness of different amounts of nighttime nap sleep in night shift schedules with restricted daytime sleep has not been systematically investigated.

Methods

N=79 healthy adults (ages 28.5±6.8y; 53 males) participated in a laboratory study with 8 days of simulated night shift. Subjects were randomized to one of 18 daily sleep regimens involving restricted daytime sleep (4.2h, 5.2h, 6.2h, or 8.2h TIB centered at 14:00) combined with a nighttime nap (0h, 0.4h, 0.8h, 1.2h, 1.6h, 2.0h, or 2.4h TIB centered at 02:00). Every day at 20:10, 22:10, 00:10, 04:10, 06:10, 08:10 (all post sleep inertia), subjective sleepiness and vigilant attention were assessed with the Karolinska Sleepiness Scale (KSS) and Psychomotor Vigilance Test (PVT), respectively. For each subject, circadian change was determined as the difference between the daily peak and trough of KSS scores and PVT lapses (RT>500ms). Daily peak sleepiness and circadian change were analyzed using mixed-effects regression with fixed effects for nighttime nap TIB (categorical), night shift day, and their interaction; covariates for daytime sleep TIB (categorical) by itself and in interaction with day; and a random effect over subjects on the intercept.

Results

Nap duration influenced KSS daily peak (F[6,543]=2.25, P=0.037) and circadian change (F[6,543]=3.18, P=0.005), with 0h TIB (no nap) yielding the highest peak and circadian change (P< 0.05), 0.8h TIB the lowest (P< 0.05), and no significant differences comparing the other nap durations. Nap duration did not significantly affect PVT daily peak impairment (P=0.36) or circadian change (P=0.16).

Conclusion

Nighttime napping of any duration (0.4h–2.4h TIB) centered at 02:00 has the potential to mitigate peak subjective sleepiness during night shift schedules with restricted daytime sleep. This napping effect does not appear to extend to impairment in objectively measured vigilant attention. More research is needed to understand the extent to which performance and safety benefit from nighttime napping under conditions of sustained daytime sleep restriction during night shift schedules.

Support (if any)

NASA NCC 9-58-159 with NSBRI
0143 Effects of Optimal-timed Automatic Awakening from a Short Daytime Nap on Cognitive Performance and Fatigue
Authors: Abe Takashi , Suzuki Yoko , Suzuki Chihiro , Ohigashi Tomohiro , Maruo Kazushi , Watanabe Yumi , Endo Junki , Watanabe Takahiro
Published: April 2024

Introduction

Daytime naps, although known to improve performance, can impair performance if overextended, as slow-wave sleep causes sleep inertia. Hayashi et al. (2014) showed that a nap duration of 9 min after N2 onset maximized performance. However, awakening 9 min after N2 is challenging, other than in sleep laboratories, because it requires manual polysomnography (PSG) scoring. We developed a system that automatically awakens 9 min after N2 by an automatic sleep stage estimator using a blood flow meter and investigated whether this improved performance, sleepiness, and fatigue compared to no napping and also its effectiveness as compared to manual awakening.

Methods

Eighty-one healthy adults (33.6±12.8 years [mean ± standard deviation], 47 women) were randomly assigned to three groups of 27 participants each: automatic awakening, manual awakening, and rest. The digit symbol substitution test (DSST) was used to evaluate cognitive speed and visual detection task (VDT) to evaluate attention. The Karolinska Sleepiness Scale and the visual analog scale were used for the sleepiness and fatigue evaluation; the tasks were performed thrice after attaching the PSG and used as a baseline. The automatic and manual awakening groups napped wearing the blood-flow-meter device. The latter group was awakened 9 min after the N2 onset. The participants in the rest group remained awake for 22 minutes. After the nap or rest, the task was performed again for six sessions consisting of three times tasks. Groups were compared for the changes detected from the baseline in each session.

Results

The automatic awakening group woke up 19.6 ± 6.0 (mean ± standard deviation) [min-max 7.9–27.1] min from N2. Subjective sleepiness and fatigue in the automatic awakening group decreased compared to the rest group in all sessions and were comparable to those in the manual awakening group; the number of correct answers on the DSST increased in the sixth session for manual awakening compared to rest. VDT did not differ between groups.

Conclusion

Napping with the automatic awakening device improved sleepiness and fatigue comparable to manual awakening.

Support (if any)

This work was funded by Kyocera Corporation.
0144 The Impact of Controlled Rest on Neurobehavioral Outcomes at Top-Of-Descent
Authors: Hilditch Cassie , Arsintescu Lucia , Pradhan Sean , Gregory Kevin , Flynn-Evans Erin
Published: April 2024

Introduction

Long and irregular working hours can lead to fatigue in aviation operations. In some regions, a short nap taken on the flight deck (known as controlled rest) can be used as a countermeasure to unexpected in-flight sleepiness. We aimed to investigate the impact of taking controlled rest on neurobehavioral measures at top-of-descent.

Methods

Data from 120 long-haul (> 6 h flight duration), unaugmented flights were analyzed (n = 31 pilots). Pilots wore actigraphs and completed sleep logs before and during trips. At pre-flight and top-of-descent, pilots completed a 5-minute psychomotor vigilance task (PVT) and Karolinska Sleepiness Scale (KSS). A series of mixed-effects models were conducted to assess the impact of controlled rest on outcome measures at top-of-descent. Sleep duration in the prior 48 hours, timing of the flight, and pre-flight scores for each measure were included as covariates.

Results

Due to missing data, complete data from 76 flights (n = 28 participants) were available in the models examining the PVT metrics, and data from 83 flights (n = 29 participants) were available in the analyses of the KSS. Pilots who took controlled rest had faster response speeds at top-of-descent (p = .03, η2p = 0.07; estimated marginal mean [EMM] = 4.19, standard error [SE] = 0.07, 95% CI [4.08, 4.29]) than those who did not take controlled rest (EMM = 4.00, SE = 0.05, 95% CI [3.86, 4.14]). There were no differences by controlled rest status for KSS scores and PVT lapses (p values > .05, η2p values ≤ 0.01).

Conclusion

Our results suggest that taking controlled rest may improve vigilant attention at critical phases of flight and, thus, may be a useful fatigue management tool during unaugmented flights. Further research is necessary to determine the impact of factors on the decision to take controlled rest (e.g., airline culture, personal preference) and how the controlled rest policy is applied in practice.

Support (if any)

NASA Airspace Operations and Safety Program, System-Wide Safety Project.
0146 Supine Sleep Position and Angina Episodes: The Sleep Heart Health Study
Authors: Logan Jeongok , Byon Ha Do , Davis Eric , Kwon Younghoon
Published: April 2024

Introduction

Poor sleep features are associated with an increased risk of cardiovascular disease (CVD). While habitual sleep postures may influence cardiovascular function, previous studies have mainly focused on the benefits of left-side sleeping during pregnancy and different sleep positions in relation to musculoskeletal symptoms. It remains largely unknown how the supine position is associated with cardiovascular risk in general populations. The purpose of this study was to examine the association of supine position with angina episodes, the most common symptom of ischemic heart disease.

Methods

This study used data form the Sleep Heart Health Study (SHHS). Sleep position was operationalized as a percentage of total sleep duration in the supine position, measured by unattended home polysomnography (PSG) during SHHS visit 1. Angina was defined as the number of episodes from baseline PSG to SHHS visit 2. Multiple regression analysis was conducted with covariates including age, race, gender, body mass index, smoking status, systolic blood pressure, history of diabetes, total sleep duration, sleep efficiency, apnea hypopnea index, hypertension medication, diabetes medication (oral or insulin), lipid medication, cholesterol, triglyceride, HDL, and psychological stress, obtained during the SHHS visit 1.

Results

The study included a total of 4458 participants (2363 females, 53%) with mean age of 64.33 years old and a mean systolic BP of 125 mmHg. The mean of supine position was 33.64% and the mean number of angina episodes was 0.54. The supine position was an independent predictor of the number of angina episodes (p=<.001). A one standard deviation increase in the supine position resulted in 0.076 standard deviations increase in the number of angina episodes (β=.076), while age and body mass index resulted in .077 and .098 increase in the outcome (β = .077, p=<.001; β = .098, p=.<.001).

Conclusion

Sleeping in the supine position was significantly associated with the number of angina episodes. However, the current study lacks specific information regarding the percentage of sleep duration in non-supine positions (either left/right side or prone position). Identifying sleep positions optimal for facilitating cardiovascular function may make a meaningful contribution to CVD prevention.

Support (if any)
0148 Interconnected Dynamics of Sleep Duration, Social Media Engagement, and Neural Reward Responses in Adolescents
Authors: Kiss Orsolya , Zhang Linhao , Müller-Oehring Eva , Bland-Boyd Brittany , Harkness Anya , Kerr Erin , Durley Ingrid , Arra Nicole , Camacho Leticia , Tager Lucas , Fan Ruby , Perez-Amparan Evelyn , Gombert Marie , Nagata Jason , Baker Fiona
Published: April 2024

Introduction

In today’s digital landscape, social media features prominently in adolescents’ social interactions and information consumption, influencing their development, potentially altering brain processes. Research shows a bidirectional relationship between social media use and both sleep health and brain activities, especially in executive control and reward processing. These neural developments are pivotal in adolescent behavioral and psychological growth, with sleep being crucial yet underexplored in the context of reward, social (media) behaviors.

Methods

This study investigated the reciprocal links between social media use, self-reported sleep duration, and brain activation in 6,516 adolescents (ages 10-14 years, 46.2% female) from the Adolescent Brain Cognitive Development (ABCD) Study®. Sleep duration was assessed from the Munich Chronotype questionnaire, and recreational social media use through the Youth Screen Time Survey. Brain activities were analyzed from fMRI scans during the Monetary Incentive Delay (MID) task, targeting regions associated with reward processing. The study used three different sets of models, switching predictors and outcomes each time, to examine the reciprocal relationships between sleep duration, brain activation, and social media use, and their interactions. Age, COVID-19 pandemic timing (before/during), and socio-demographic characteristics were included in the models.

Results

Shorter sleep duration correlated with greater social media usage (p<.001). Notably, interactions between sleep duration and brain activation in the cingulate gyrus (p=.021), inferior frontal gyrus (p=.009), and precuneus (p=.008) predicted social media use. In predicting brain activity, interactions between sleep duration and social media use emerged as significant for the inferior (p=.008) and middle frontal gyrus(p=.003). For sleep duration predictions, interactions were important between social media use and brain activation spanning seven areas, including the cingulate gyrus (p=.039), hippocampus (p=.005), insula (p=.015), inferior frontal gyrus (p=.001), middle frontal gyrus (p=.003), precuneus (p=.038) and the superior frontal gyrus (p=.028).

Conclusion

These results highlight distinct relationships between sleep, social media, and activity across frontolimbic brain regions, key for executive control and reward processing. Such insights deepen our understanding of how individual's unique neural sensitivities to digital technology use and sleep necessity interact in adolescents. Future longitudinal studies based on these findings could pave the way for developing more nuanced, individualized interventions.

Support (if any)

NIH: U01DA041022 and R01MH128959.
0149 Perception of Prior Sleep-Wake State upon Abrupt Exogenous Awakenings
Authors: Hilditch Cassie , Costedoat Gregory , Bathurst Nicholas , Shattuck Nita , Flynn-Evans Erin
Published: April 2024

Introduction

The period immediately following an awakening is characterized by sleepiness, poor cognitive performance, and disorientation known as sleep inertia. In an exploratory analysis, we investigated the accuracy of perceived sleep-wake state after being abruptly awoken.

Methods

Thirty-six participants (18 female; 26.6 years ± 6.1) slept in their own homes and were called on a pre-set cell phone three times: twice during their habitual sleep period (approximately 45 min and 135 min after habitual bedtime) and once at their habitual waketime the next morning (n = 108 awakenings). Sleep stage prior to waking was measured by polysomnography. Researchers observed participants remotely via an infrared camera. Participants were asked whether they thought they had been ‘asleep’, ‘awake’, or ‘unsure’ immediately prior to receiving the phone call.

Results

Polysomnography determined that participants were asleep prior to the call for 88.0% (n = 99) of the awakenings (Wake: 8.3%, N1: 10.2%, N2: 27.8%, N3: 38.9%, REM: 11.1%, Undefined: 3.7%). Participants were asleep for all instances in which the self-perceived state prior to awakening was ‘asleep’. When state was self-perceived as ‘awake’ or ‘unsure’, participants were awake 25% of the time and in N3 sleep 19% of the time (sensitivity: 71.6%; specificity: 100%). One-fifth (n = 7) of the cohort were unable to correctly identify being asleep on multiple awakenings.

Conclusion

Participants correctly identified themselves as being asleep with moderately low sensitivity, but high specificity. Interestingly, even participants in deep sleep stages (N3) sometimes perceived themselves to be awake before the call. A portion of participants were consistently poor at identifying being asleep. These misperceptions of sleep-wake state upon awakening may contribute to the disorientation experienced during the sleep inertia period and may be influenced by individual differences. Although the uneven distribution of sleep-wake states in this sample limits us to descriptive statistics, our exploratory analysis suggests that a systematic assessment of perception during the sleep-wake transition and its subsequent effect on alertness, cognitive performance, and decision making is warranted.

Support (if any)

Naval Postgraduate School, via the Naval Medical Research Center's Naval Advanced Medical Development Department (MIPR N3239820WXHN007). NASA Airspace Operations and Safety Program, System-Wide Safety.
0154 Effects of Fatigue on Operational Performance in Navy Expeditionary Robotics Operators: A Descriptive Study
Authors: Dunn Timothy , Schrom Brandon
Published: April 2024

Introduction

Expeditionary robotics operators have a unique mission set within the Navy. These operators utilize small vessels and various robotics systems to achieve missions in austere settings. Those missions often require that operators perform their job under varying environmental conditions that have the potential to induce high levels of fatigue.

Methods

Four platoons (1, n = 10; 2, n = 9; 3, n = 9; 4, n = 11) that were enrolled in a training unit underwent a 5-day field exercise designed to simulate the operational settings of being deployed. Participants were issued a Fatigue Science ReadiBand to collect actigraphy that calculated metrics such as sleep quantity, quality, efficiency, and an alertness score. Operational data (errors) were provided to the research team via the training unit instructor staff. Participants completed the Need for Cognition Scale pre-exercise and the Intrinsic Motivation Inventory (IMI) post-exercise.

Results

Three platoons (1, 3, and 4) completed the entire exercise while platoon 2’s exercise was cut short 1 day early due to making too many critical errors. The total number of operational errors were as follows: platoon 1 committed 9 errors; platoon 2, 5 errors; platoon 3, 10 errors; and platoon 4, 2 errors. Platoons 1 and 4 showed a similar downward trend in alertness throughout the exercise, while platoons 2 and 3 had similar but more stable alertness profiles during the exercise. Sleep quality and sleep efficiency were lower in platoons 1 and 4 compared with platoons 2 and 3. Data from the IMI indicated that platoons 1 and 4 demonstrated that they felt more pressure during the exercise than platoons 2 and 3.

Conclusion

Platoon fatigue was not related to operational performance in a straightforward manner. Platoons 1 and 4 were the most operationally competent platoons per instructor feedback, though they experienced lower levels of alertness, worse sleep, and committed more or a similar number of errors relative to the other platoons. It is possible that platoons 1 and 4 were able to compensate in ways that allowed them to overcome heightened fatigue. This highlights the in-depth analyses required when assessing operational fatigue and performance during field operations.

Support (if any)
0155 The Influence of Subjective Sleepiness on Solider Fatigue During a 72-Hour Live-Fire Mission Simulation
Authors: Jones Rachell , Eldringhoff Hannah , Carlsson Kajsa , Overman Grace , Chaudhury Sidhartha , Bode Victoria , Elkin-Frankston Seth , Elmore Wade , Bovard Pooja , Brown Stephanie , Burke Tina
Published: April 2024

Introduction

The military works under 24/7 operations which can lead to sleep loss and Soldier fatigue. Both sleep loss and fatigue impact functionality and success of the Soldier and ultimately, the entire unit. The functional impact of sleepiness and fatigue can be present differently. Therefore, clarifying the relationship between subjective sleepiness and fatigue is important for military readiness and provides leadership with critical information to ensure mission success.

Methods

Fifty-one healthy, young male participants were recruited from a sample of active-duty Soldiers. The study lasted 5 days with a 72-hour live-fire mission simulation from days 2 to 4. On each of these days, Soldiers completed daily morning surveys, including measures of sleepiness using the Epworth Sleepiness Scale (an 8-question measure to identify clinical sleepiness) as well as subjective fatigue through the Visual Analog Scale.

Results

A repeated measures ANOVA showed a significant main effect for subject sleepiness and fatigue among mission days (p < 0.05). Linear regression indicated sleepiness scores were significantly predictive of fatigue each mission day.

Conclusion

On mission day 3 during the 72-hour live fire mission, soldiers were significantly more sleepy and more fatigued compared to other mission days. Additionally, for each mission day, subjective sleepiness was predictive of soldier fatigue. Understanding this relationship and its predictive nature can help military leadership plan accordingly for mission and training events to maximize success in operational contexts.

Support (if any)

Department of Defense Military Operational Medicine Research Program (MOMRP); DEVCOM SC
0158 Nighttime Snacking and Sleep: Comparing Commercially-Available Snacks Consumed Before Bed
Authors: Folkson Sean , Broch Lauren , Tubbs Andrew , Grandner Michael
Published: April 2024

Introduction

Most Americans snack at night, though caloric consumption and consumption of certain nutrients and ingredients at night can contribute to sleep disruption and cardiometabolic disease risk. Chips, cookies, ice cream and candy are the most popular snacks consumed before bed. Perhaps certain snacks at night can minimize risks to sleep and cardiometabolic health due to nutritional profile, ingredient composition, and other factors.

Methods

Seventy-seven adults completed a 5-week open-label crossover study. They consumed the same snack each night for 3 days, then had a 4-day washout before switching to the next product. Product order was randomized and included NightFood ice cream (NF; product of interest), Halo Top ice cream (HT; “healthy” comparator), Ben & Jerry’s ice cream (B&J; “indulgent” comparator), Lay’s potato chips (LAYS; non-ice cream comparator), and no snack. Participants completed daily ratings (3-day mean) for daytime energy, evening cravings, nighttime relaxation, feelings of satisfaction, bloating/discomfort, difficulties initiating and maintaining sleep, feeling refreshed, and sleep continuity (sleep latency, wake after sleep onset, awakenings). Linear mixed models were adjusted for order.

Results

B&J was associated with lower daytime energy vs no snack. B&J and NF were associated with more relaxation at night vs LAYS. All three ice-creams were more satisfying vs LAYS post-snack, but NF and B&J were much more satisfying than HT, and not different from each other. HT and NF were rated lower on bloating/discomfort than LAYS, while B&J was rated much higher. Individuals went to bed earlier if they ate LAYS (~40 minutes), or NF (~25 minutes) vs no snack. Compared to no snack, individuals who ate NF were less likely to report difficulty initiating sleep or returning to sleep, greater sleep quality, and greater feelings of rest and energy the next morning. Conversely, individuals who ate B&J had worse sleep quality and energy the next morning.

Conclusion

Snacks formulated to satisfy cravings while minimizing sleep disruption and including ingredients that may support sleep may be a preferable option for individuals who choose to snack at night. Future work is needed to better understand how to minimize risks and potential adverse impacts of nighttime snacking.

Support (if any)

NightFood
0159 Age as a Moderator for the Relationship Between Exercise Before Bed and Daytime Sleepiness
Authors: Mastin David , Bryson W , Moore Bruce , Peszka Jennifer
Published: April 2024

Introduction

It is axiomatic that sleep and exercise are important for good health. However, in the Sleep Hygiene Index (SHI), we suggest exercise within one hour of bedtime is a sleep-related behavior to avoid. More recently, in a systematic review no support was found for evening exercise negatively affecting sleep. Here, we examine age as a moderator for the relationship between sleep and sleep outcomes to reconcile these findings.

Methods

Data were gathered from 10 previous studies from our laboratory administering the SHI and at least one sleepiness measure (Epworth Sleepiness Scale (ESS) and/or the Pittsburgh Sleep Quality Index (PSQI). Participants included primarily college students but also non-college student populations (faculty/staff, alumni, parents, and local community members). This sample included 1668 18-23 year-olds, 219 24-39 year-olds, and 199 40-85 year-olds. Participation was incentivized with bonus points or opportunities to win gift cards. Focus here was on the SHI exercise question (“I exercise to the point of sweating within 1 h of going to bed”) answered on a 5-point scale (1=never to 5=always).

Results

Intense exercise within one hour of bed was not common (18-23 year-olds, M=1.58; 24-39 year-olds, M=1.48; 40-85 year-olds, M=1.36). The correlation between exercise and sleepiness measures was quite small (ESS, r(1570)=0.094; PSQI-Global, r(1526)=0.027, and PSQI-Daytime Dysfunction, r(1557)=-0.045). However, the relationship between exercise and sleepiness was significantly moderated by age (b=.935, t(1462)=3.55, p<.001). Although there was no significant relationship for the youngest participants between exercise and sleepiness, a significant small (β=0.09) positive relationship for the middle age group (b=.412, z=3.66, p<.001) and a small to medium (β=0.19) positive relationship for the oldest participants (b=.819, z=5.02, p<.001) existed.

Conclusion

These findings suggest age moderates the relationship between exercise close to bed and sleep outcomes. Although resiliency may protect the young, middle aged and older adults are likely to be vulnerable to pre-sleep exercise. We found although exercise close to bed did not predict sleepiness in younger participants, for older participants the negative effect of exercise close to bed was apparent and increased with age. Clinically, age may be an important variable to consider when advising against exercise before bed.

Support (if any)
0160 Resistance Exercise in the Luteal Phase Promotes Heat Loss and Increases Delta Power During Nocturnal Sleep
Authors: Fushimi Momo , Iijima Ryusei , Kiyama Mizuki , Kubokawa Himeka , Sugawara Konomi , Takakura Mariko , Noguchi Shiori , Aritake-Okada Sayaka
Published: April 2024

Introduction

Fluctuation in body temperature rhythm are associated with the menstrual cycle and closely relate to sleep. In particular, during the luteal (high temperature) phase (LP), sleep quality during nocturnal sleep decreases and daytime sleepiness increases. Menstrual cycle-related sleep disturbance can negatively impact a woman’s social life. In this study, we investigated the effect of exercise on body temperature, heat loss, nighttime sleep, delta power, and subjective evaluation during the follicular phase (FP) and LP in young-adult women.

Methods

Twelve young-adult females participated in the experiment for a total of 4 days over the course of their menstrual cycle: 1) FP non-exercise condition, 2) FP exercise condition, 3) LP non-exercise condition, and 4) LP-exercise condition. Exercise consisted of 40 minutes of resistance exercise training (RT) at 70% one repetition maximum during the day. Electroencephalography (EEG), electro-oculography, chin surface electromyography, skin temperature, and tympanic temperature were measured simultaneously at the subject’s home overnight, and distal-proximal-skin-temperature-gradient was calculated. Sleep EEG data were scored for 30 s epoch periods according to the American Academy of Sleep Medicine Scoring Manual by a registered polysomnographic technologist. Power spectral analysis using the fast Fourier transform (FFT)algorithm was conducted. The study was approved by the Ethics Committee of Saitama Prefectural University.

Results

RT promoted heat loss and increased stage N3 sleep during nocturnal sleep in both the FP and LP. When the distribution of stage N3 duration and delta-power in the sleep period was analyzed, stage N3 sleep and delta power persistence occurred in the second half of the nocturnal sleep period, especially in the LP-exercise condition. The heat loss was also higher and coincided with the increase of delta power in the LP-exercise condition.

Conclusion

RT promoted heat loss, slow wave sleep, and delta power also in the latter half of the nocturnal sleep in the LP, when body temperature is higher and heat loss are disrupted. Encouraging RT during the LP may help women to overcome sleep disturbance associated with this phase of the menstrual cycle.

Support (if any)
0161 Preliminary Findings on the Moderating Effects of Exercise on Tobacco Use and Sleep
Authors: L’Houtellier Nina , Nechyba Ashley , Montalvo Jessica , Elvariste Stessie , Oliveira Bruno , Blanc Judite , Seixas Azizi , Moise Rhoda , Jean-Louis Girardin
Published: April 2024

Introduction

It is widely understood that the use of tobacco has negative effects on several health outcomes such as sleep disturbances. With all the readily available information concerning these negative factors, there is still a significant use of tobacco amount Black and African American individuals in the United States. This study aims to find any correlation between sleep, exercise, and tobacco use amongst this population.

Methods

A comprehensive statistical analysis was performed using the combined data of both MOSAIC (n=267) and ESSENTIAL’s (n=476) data. These are NIH funded studies that are currently active and being conducted. These studies comprised only of Black or African American (n=221 Male; n=424 Female) individuals living in South Florida or New York. Among the 743 participants, 207 reported having smoked at least 100 cigarettes in their life vs non- smokers (n=404). Participants in both the MOSAIC and ESSENTIAL study followed similar procedures. A self-reported baseline survey in Phase 1 consisting of several assessments such as: The Holmes-Rahe Stress score(SS), Everyday Discrimination Scale (EDS), Sleep Disturbances (SD), Insomnia Severity Index (ISI), and Assessment of Sleep Environment (ASE) were used for these findings. Phase 2 consisted of wearing several sleep devices for a 7-day period. Of these devices we utilized the objective data found in the Fitbit activity counter for steps taken.

Results

Of the 743 participants significant t-test values were observed across previously mentioned parameters. With significant findings across the mean scores of the following variables; SS (t=-8.408 , df= 741, p<.001), EDS(t=-18.642, df=741, p<.001), SD(t=-5.644, df=741, p<.001), ISI (t=-11.899, df=741, p<.001), ASE (t=-42.931, df=741, p<.001), and Fitbit Steps (t=-.922,df=232, p=.040). No significant or strong associations were found in a regression linear analysis between steps, ISI, and tobacco use.

Conclusion

Differences in mean scores were found to be significant amongst these variables. Although these results were significant, future research is necessary to find if exercise may have a moderating effect on tobacco use and sleep.

Support (if any)

NIH R01HL142066 R01AG067523
0163 Longitudinal Assessment of Objective Sleep and Power Output During Fall Training in Division I Collegiate Athletes
Authors: Bigalke Jeremy , Lee Katherine , Bigalke Jennifer , Scullin Michael , Gallucci Andrew , Carter Jason
Published: April 2024

Introduction

Cross-sectional analyses have linked poor sleep to impaired athletic performance. While acute sleep restriction impairs athletic performance, longitudinal investigation of intraindividual sleep and performance variations over time have been sparsely assessed. The purpose of the present study was to determine the relationship between objective habitual sleep and peak power output variations over fall training in Division I collegiate baseball players. We hypothesized that greater total sleep time (TST) and better sleep efficiency (SE) among athletes would be associated with greater improvements in peak power output throughout fall training.

Methods

Twenty-three healthy college baseball players (age: 21±1 years) participated during fall training. Peak power output was assessed weekly for twelve weeks. During the final six weeks of the fall season, all participants were asked to wear Oura rings to objectively determine daily TST and SE within each athlete. The slope of change in peak power output (Pslope) across fall training was compared to objective sleep outcomes. To assess the impact of intraindividual consistency in achieving adequate sleep, Pslope was also compared to the proportion of nights in which TST met or exceeded 7 hours, and the proportion of nights which sleep efficiency met or exceeded 90% within each participant.

Results

Over the 6-wk sleep assessment, participants had a TST of 7.3±1 hours per night and a SE of 89±2%. TST (r=0.398, p=0.067) and SE (r=0.356, p=0.096), demonstrated medium-sized associations with Pslope. The proportion of nights during which TST met or exceeded 7 hours showed a pronounced association with Pslope (r=0.525, p=0.010). Similarly, the proportion of nights during which SE met or exceeded 90% was significantly associated with Pslope (r=0.471, p=0.023). Lastly, the number of nocturnal awakenings was inversely correlated with Pslope (r=-0.468, p=0.024).

Conclusion

Sleep quantity, quality, and consistency during the collegiate baseball fall training showed medium to large associations with improvements in peak power. Further research is needed to establish a causative, mechanistic relationship between sleep and associations with training performance outcomes.

Support (if any)