bluuebunny/crossref_metadata_2025 huggingface dataset:
0097 REM-like Neural Activity Is Superior to NREM Parameters for Predicting Non-sleep Restricted Vigilance
Authors: Vattikuti Shashaank , Balkin Thomas , Braun Allen , Riedy Samantha , Doty Tracy , Hughes John
Published: May 2022

Introduction

Currently unknown is whether REM-like neural activity reverses, incurs, or is neutral with respect to its effect on sleep pressure independent from NREM recovery. We investigated the relationship between a novel scalp-EEG measure of REM-like neural activity and next-day performance on the Psychomotor Vigilance Task (PVT) – a sensitive measure of sleep debt. Our EEG measure reflects the oscillatory-theta activity (OTA) that is the hallmark of REM sleep in animal studies. This method preserves amplitude information, isolates OTA from aperiodic theta-band power, and accounts for REM-like activity thought to occur outside of conventionally scored-REM epochs. We compared the PVT-association of OTA, traditionally measured EEG REM-theta, and traditional sleep parameters. To assess REM-like independent effects, we controlled for traditional parameters using a multivariate model.

Methods

Our method uses Irregular-Resampling Auto-Spectral Analysis to remove the aperiodic spectrum, followed by low-band power normalization to derive the relative oscillatory-theta activity (OTA). The average OTA was then used to predict next-day performance on the PVT. Traditional sleep parameters (sleep efficiency, total sleep time, %NREM, %N3, and delta-band power) were also examined. We combined data from two previously reported in-laboratory studies resulting in a sample size of 42 healthy young adult subjects. Analyses used non-sleep restricted overnight EEG recordings from a frontal channel.

Results

There was a substantial PVT-OTA association (OTA positively correlated with response-time and thus with reduced vigilance) during scored-REM epochs (r=0.44, p=0.003). This was stable irrespective of conventional sleep staging when using all sleep epochs (r=0.48, p=0.001), and OTA during scored-NREM (r=0.35, p=0.02). The effect was also stable after controlling for total sleep time, %NREM, and N3 delta-band power in a multivariate model (all-sleep PVT-OTA: r=0.5, p=0.004). Traditional sleep parameters were not significantly correlated with PVT performance.

Conclusion

OTA was a superior quantitative predictor of reduced next-day vigilance than traditional sleep parameters, and this persisted after controlling for NREM parameters. These findings are consistent with the hypothesis that periods of high REM-like activity are less restorative than other periods and may actually increase homeostatic sleep pressure.

Support (If Any)

This effort was supported by the Department of Defense Military Operational Medicine Research Program.
0098 A Model for a Chronic Napping in Older Adults at Risk for Alzheimer’s Disease
Authors: Youngstedt Shawn , Angadi Siddhartha , Petrov Megan , Patel Salma
Published: May 2022

Introduction

Theoretically, napping could have positive effects on health (e.g., by reducing stress and compensating for short night time sleep) or negative effects (e.g., by disrupting nighttime sleep or impairing circadian synchronization). Epidemiologic studies have produced mixed results regarding associations of napping with health. Causality can be better addressed with a randomized controlled trial of daily napping, as described herein.

Methods

Participants were 12 older adults (70.8±4.4 years) with a first degree relative with Alzheimer’s Disease. Inclusion criteria included normal cognitive function; stable sleep schedule; stable medication use; and self-reported ease of taking naps, but with napping frequency of ≤2 days per week. Exclusion criteria included having a sleep disorder or high risk of obstructive sleep apnea; hypertension; sleeping pill use > once per week; MI or stroke within the past 3 years. Following a one week baseline involving a stable sleep/nap schedule consistent with usual habits, participants were randomized to one of two 21-day treatments: (1) daily napping (1 h/day begun at 5-7 h after arising) while keeping a stable night sleep schedule consistent with baseline (n=6); (2) a no-napping control treatment in which participants read quietly for 1 h/day at the same time (n=6). Sleep for night sleep and napping (or non-napping) was assessed via self-report, actigraphy, and the Z-machine.

Results

ANOVA revealed a significant increase in napping minutes/day (p=0.01) in the napping treatment (baseline: 14.5±21.1; 21-day average: 42.1±19.1) compared with the control treatment (baseline: 2.2±5.5; treatment: 1.4±3.5). However, reported nightime sleep duration did not change significantly between the napping (from 7.1±1.2 to 7.4±1.0 h) and the control treatment (7.8±0.7 to 7.8±0.6 h). Actigraphic night sleep changed from 7.3±0.8 to 7.1±0.9 and 7.8±5 to 7.6±0.7 after napping and control, respectively. There were not significant treatment differences (nor notable effect size differences) for depressed mood, sleepiness, PSQI, amyloid beta, nor cardiovascular measures (e.g., blood pressure, flow mediated dilation, pulse wave velocity).

Conclusion

The data indicate that older adults can undergo daily napping without significant impairment in nighttime sleep. Neither benefits nor detrimental effects on health-related variables were shown in this small sample. A more prolonged intervention is needed.

Support (If Any)

Institute for Social Science Research (ASU)
0107 Everyday Daytime Executive Functions in Adolescents with Insomnia
Authors: Gruber Reut , Saha Sujata , Voutou Denise , Somerville Gail , Panaitescu Antonia , Boulanger Carolynn
Published: May 2022

Introduction

Current diagnostic criteria for insomnia require self-reported sleep difficulties along with a complaint of daytime impairment. Despite the high prevalence of insomnia in adolescents, its daytime correlates are not well characterized in this age group. Executive functions (EFs) are high-level cognitive processes that coordinate memory, attention and emotions, all of which are utilized in daily functioning. Sleep deprivation impairs performance on tasks requiring EFs.A number of studies have examined the associations between insomnia and EFs in adults, but there is a paucity of studies examining EFs in adolescents with insomnia. This limits the understanding of the nature of daytime functioning in adolescents with insomnia, and impedes efforts to examine the effectiveness of interventions aimed at alleviating the daytime impairment of adolescents with insomnia.Study Objectives: 1) To compare everyday executive functioning of otherwise healthy adolescents with insomnia and that of typically developing controls; and 2) To examine the associations between sleep and everyday EFs in otherwise healthy adolescents with insomnia.

Methods

37 boys and 59 girls aged 12–16 years (mean=13.29; SD=1.1) with no medical or psychiatric disorders were divided into three groups based on their Insomnia Severity Index score: No insomnia ISI <7; Sub-threshold insomnia 8< ISI <15; Insomnia ISI> 15. Insomnia was measured using the ISI. Everyday executive functioning was measured using the Behavior Rating Inventory of Executive Function (BRIEF). Sleep was measured using Actigraphy (AW-64 series; Mini-Mitter, Sunriver, OR, USA) and sleep logs. The parents of each participant provided information regarding his/her demographic and health status.

Results

Adolescents in the Insomnia group had higher scores on the BRIEF’s Metacognition Index (F(2, 94)=3.1, p<0.05) and Global Executive Composite (F(2, 94)=3.6, p<0.05) and marginally shorter actigraphic sleep duration compared to the other groups ((F(2, 94)=2.5, p<0.09]). Negative correlations were found between actigraphic sleep duration and scores on the BRIEF’s Behavioral Regulation Index, Metacognition Index, and Global Executive Composite [r(81)= -0.35 p<.001 r(81)= -0.49 p<.001 r(81)= -0.42 p<.001, respectively] and between sleep efficiency and the Metacognition Index [r(81)= -0.23 p<.05].

Conclusion

ConclusionInsomnia in adolescents is associated with poor EFs.LimitationThe cross-sectional nature of the study means that the association between insomnia and EFs could be bidirectional.

Support (If Any)

CIHR 418638 to Reut GruberRGPIN-2015-04467 to Reut Gruber
0108 The Effect of Reward Motivation on Placekeeping Performance After Sleep Deprivation
Authors: Wernette Elle , Altmann Erik , Fenn Kimberly
Published: May 2022

Introduction

Sleep deprivation impairs some higher-order cognitive processes, but this impairment may reflect changes in motivation as well as changes in the cognitive capacity to perform the task, which has implications for intervention strategies. Here, we asked whether reward motivation could offset the effects of sleep deprivation on placekeeping, a higher-order cognitive process that is prevalent in performance of everyday tasks. To conduct this study under pandemic conditions, we developed a method for online data collection that promises to facilitate sleep-deprivation research more generally, by allowing for larger and more diverse samples to be collected at lower cost compared to in-person methods.

Methods

In the evening, participants joined a Zoom meeting and completed the Psychomotor Vigilance Task (PVT) and a placekeeping task (UNRAVEL). Afterwards, participants were randomly assigned to remain in the meeting and stay awake (Deprivation) or leave the meeting and sleep (Rested). Deprivation participants were monitored remotely overnight by two research assistants. Rested participants left the meeting at 00:00 and returned at 08:30. At 08:30, all participants completed the PVT and UNRAVEL again. Some participants had the opportunity to earn a monetary reward based on their morning UNRAVEL performance (Motivated) and some did not (Nonmotivated). We analyzed morning performance with a 2 (Sleep: Rested, Deprivation) x 2 (Reward: Motivated, Nonmotivated) design using evening performance as a covariate.

Results

Preliminary results from 206 participants show Deprivation participants had more placekeeping errors and lapses in the PVT than Rested participants. Motivated participants made fewer placekeeping errors after task interruption than Nonmotivated participants. The Sleep and Reward factors did not interact.

Conclusion

These results suggest that motivational interventions can mitigate some effects of sleep deprivation on complex task performance. However, reward motivation affected Rested and Deprivation performance similarly rather than compensating for any effects specific to sleep deprivation. This pattern does not rule out an effect of sleep deprivation on motivation, but does suggest that a different approach will be necessary to isolate this effect.

Support (If Any)

This research is funded by the Office of Naval Research (N00014-20-1-2739).
0141 Daily self-reported sleep duration patterns among male and female collegiate athletes
Authors: Bretzin Abigail , Weeks Jeremy , Walts Cory , D'Alonzo Bernadette , Wiebe Douglas
Published: May 2022

Introduction

Student-athletes’ time demands include scholastic, athletic, and social events that may influence sleep duration; and the association between sleep duration, athletic performance, and injury risk are inconclusive. Further, limited research investigates long-term habitual sleep patterns in collegiate student-athletes. We aimed to describe the feasibility of monitoring long-term self-reported sleep duration, within-person sleep duration patterns, and test sex differences across a semester in a collegiate student-athlete cohort.

Methods

We monitored daily self-reported sleep in a prospective cohort study using ecologic momentary assessment. Each day, a smartphone application prompted student-athletes to record total sleep hours obtained in the previous 24 hours(h). We provide descriptive statistics for response frequency, and within-person sleep, percentage of days below recommended (7-9) hours, and coefficient of variation (CV) [(standard deviation/mean)*100]. We tested sex differences using chi-squared tests, and within-person median hours of sleep on weekdays verses weekends with paired t tests (p<.05).

Results

Sixty-three student-athletes (male: 57.1%) on eight teams responded. Out of a possible 54 responses, response frequency was <25% for 27.0% of student-athletes, 25-50% for 19.1% of student-athletes, 50-75% for 20.6% of student-athletes, and ≥75% for 33.3% of student-athletes. Among those responding ≥50% of days (n=34), median self-reported sleep ranged 6.5-9h per 24h and the percent of days below recommended hours of sleep ranged from 0-53.6%. The CV ranged from 6.2-31.8% overall, and from 7.0-24.1% among athletes with response rate ≥50%. There was a significant association between sex and quartile of response rate (χ23=15.91, p<.001); the highest percent of males (41.7%) had <25% response rate, whereas 55.6% of females had ≥75% response rate. There was no association between sex and reported sleep above or below recommended hours (χ22=2.25, p=0.32). There was no difference between median within-person weekday and weekend hours of sleep (t51=0.75, p=0.46).

Conclusion

Student-athletes generally self-reported obtaining the recommended total sleep; however, participation was variable as response frequency was ≥75% for one-third of student-athletes and females responded more often than males. This suggests future studies should validate the reliability of self-report with objective data in this population to obtain complete data to appropriately assess associations between habitual sleep patterns and injury risk, performance, and recovery outcomes.

Support (If Any)

Pilot funding through the Penn Injury Science Center (CDC R49 CE 003083) supported this study.
0149 Reliability of Heart Rate Variability during Stable and Disrupted Polysomnographic Sleep
Authors: Kerkering Emma , Greenlund Ian , Bigalke Jeremy , Migliaccio Gianna , Tikkanen Anne , Nicevski Jennifer , Carter Jason
Published: May 2022

Introduction

Heart rate variability (HRV) is a common metric to estimate autonomic activity during sleep. Frequency-domain HRV is quantified as low (LF) and high (HF) frequency, whereas HRV time-domain indices include root mean square of successive R-R interval differences (RMSSD), and percentage of successive R-R intervals differing by more than 50ms (pNN50). Despite high HRV use during sleep, it is unknown whether sleep disturbance changes overall reliability of frequency- and time-domain HRV. The purpose of this present study was to determine whether HRV was reliable across arousal-free and arousal-containing periods of sleep.

Methods

Twenty-seven participants (11 male, 16 female, 26±1 years, 27±1 kg/m2) were given an 8-hour sleep opportunity, equipped with continuous two-lead electrocardiography (ECG) and overnight polysomnography (PSG). The ECG recordings were analyzed via fast-Fourier transformation for frequency-domain HRV in a custom software as LF (0.04-0.15 Hz) and HF (0.15-0.4 Hz) HRV. Time-domain HRV was quantified as RMSSD and pNN50. Two separate stable sleep periods (range, 5-10min) absent of arousals were recorded, along with two separate disrupted periods of sleep with at least one arousal were selected in stage II sleep (N2), slow wave sleep (SWS), and rapid eye movement (REM) sleep. LF and HF HRV was log10 transformed due to non-normal distribution. Statistical analysis included intraclass correlations (ICC) of HRV across the four stable and disrupted periods of sleep, with separate ICC analyses across sleep stages (α = 0.05).

Results

Time-domain measures (RRI, RMSSD, pNN50) were reliable across arousal-free and arousal-containing sleep cycles, for all three stages (ICC>0.9, p<0.05). HF HRV exhibited similar reliability patterns across N2 sleep (ICC=0.960, p<0.001), SWS (ICC=0.955, p<0.001), and REM sleep (ICC=0.924, p<0.001). LF HRV was reliable in two stages of stable and disrupted sleep in N2 (ICC=0.903, p<0.001), REM (ICC=0.907, p<0.001) sleep, and trending in SWS (ICC=0.616, p=0.089) sleep.

Conclusion

Time- and frequency-domain HRV were reliable between stable sleep with and without cortical arousals, with the exception of LF HRV during SWS. Taken together, HRV may provide a reliable, indirect index of autonomic activity across stable and disrupted sleep.

Support (If Any)

Support: Support is provided by the National Institutes of Health (AA-024892; U54GM115371; P20GM103474).
0156 Rest-activity profiles among U.S. adults in a nationally representative sample: a functional principal component analysis
Authors: Xiao Qian , Lu Jiachen , Matthews Charles , Zeitzer Jamie , Saint-Maurice Pedro , Bauer Cici
Published: May 2022

Introduction

The 24-hour rest and activity behaviors are fundamental human behaviors essential to health and well-being. Functional principal component analysis (fPCA) is a flexible approach for characterizing rest-activity rhythms and does not rely on a priori assumptions about the activity shape. The objective of our study is to apply fPCA to a nationally representative sample of American adults to characterize variations in the 24-hour rest-activity pattern, determine how the pattern differs according to demographic, socioeconomic and work characteristics, and examine its associations with general health status.

Methods

The current analysis used data from adults 25 or older in the National Health and Nutrition Examination Survey (NHANES, 2011-2014). We applied fPCA to derive profiles of the rest-activity cycle for overall, weekday and weekend activity patterns. We examined the association between each rest-activity profile in relation to age, gender, race/ethnicity, education, income and working status using multiple linear regression. We also used multiple logistic regression to determine the relationship between each rest-activity profile and the likelihood of reporting poor or fair health.

Results

We identified four distinct profiles (i.e., high amplitude, early rise, prolonged activity window, biphasic pattern) that together accounted for 86.8% of total variation in the study sample. We identified numerous associations between each rest-activity profile and multiple sociodemographic characteristics. We also found evidence suggesting the associations differed between weekdays and weekends. Finally, we reported that the rest-activity profiles were associated with self-rated health.

Conclusion

Our study provided evidence suggesting that rest-activity patterns in human populations are shaped by multiple demographic, socioeconomic and work factors, and are correlated with health status.

Support (If Any)
0165 Prevalence of insomnia and/or obstructive sleep apnea in a sample of fit-for-duty U.S. Navy sailors
Authors: Lawrence-Sidebottom Darian , Matsangas Panagiotis , Shattuck Nita
Published: May 2022

Introduction

Obstructive sleep apnea (OSA) and insomnia are prevalent sleep disorders, known to negatively impact sleep and well-being in civilian populations. Studies of these sleep disorders in military populations have focused on individuals seeking treatment for a sleep disorder, rather than the general active-duty service member (ADSM). In this study, we investigated the prevalence of OSA and insomnia in U.S. Navy sailors serving on surface ships.

Methods

We analyzed pre-collected data from 548 fit-for-duty sailors (MD age=25 years, IQR=9; 79.4% males) serving on nine US Navy surface ships. Sailors reported their demographic information, health-related habits, and whether they had been diagnosed with OSA and/or insomnia. Sleep was assessed with wrist-worn actigraphy (371 sailors).

Results

Approximately 66.8% of sailors reported having an exercise routine, 83.6% reported drinking caffeinated beverages, and 29.1% used nicotine products. In terms of disorders, 15 (2.7%) male sailors reported having been diagnosed with OSA, 12 (2.2%) with insomnia (8 males, 4 females), and one (0.2%) male sailor with comorbid insomnia and OSA. Compared to sailors without a sleep disorder, sailors with OSA were older (MD=34 years, IQR=7; p<0.001) and had a higher proportion of nicotine users (53.3%) (p=0.041). Sailors with insomnia did not differ from sailors with no sleep disorder in terms of demographics and habits. The average daily sleep duration was 6.4±1.0 hours, which did not differ between disorder groups. However, sailors with insomnia had more sleep episodes per day (MD=1.7; IQR=0.9) than sailors without a sleep disorder (MD=1.3, IQR=0.5; p=0.042).

Conclusion

Only ~5% of the sailors in our study reported a diagnosis of OSA and/or insomnia, whereas one in three people in the general population has a sleep disorder. Notably, all sailors, regardless of sleep disorder diagnosis, exhibited short sleep durations. Previous studies of ADSMs found that ~48% reported poor enough sleep quality to meet the diagnostic criteria for a sleep disorder. Thus, our results suggest that, despite evidence that many Sailors exhibited sleep problems, sleep disorders are significantly underdiagnosed in ADSMs.

Support (If Any)

This work was supported in part by the Naval Medical Research Center's Naval Advanced Medical Development Program (MIPR N3239820WXHN007).
0172 Behavioral Drive in Familial Natural Short Sleepers and Their Unaffected Family Members
Authors: Ashbrook Liza , Krystal Andrew , Fu Ying-Hui , Ptacek Louis
Published: May 2022

Introduction

Those with familial natural short sleep (FNSS) report short sleep duration since youth. Mutations in four different genes in five families have been described leading to this autosomal dominant sleep pattern. Individuals with FNSS also have a cluster of other traits in addition to short sleep than can be termed “behavioral drive.” Here we describe a new behavioral drive scale that aims to capture the distinct phenotype of those with FNSS.

Methods

Individuals reporting fewer than 6.5 hours of sleep when allowed to sleep ad libitum without any sleep-related complaint were interviewed to determine FNSS affected status from 2009 to 2021. Seven distinct non-sleep related traits were selected by consensus within the study team based on interviews with participants. Participants provided a self-rating on their degree of energy, pain tolerance, physical activity, ability to handle stress, productivity, hours working, and mental activity compared to other of the same age. Symptoms of mania and ADHD were also rated.

Results

77 individuals meeting criteria for FNSS were enrolled along with 27 unaffected family members. Compared to unaffected family members, those with FNSS reported significantly more energy, pain tolerance, physical activity, ability to sit still, hours working, and mental activity. There was a trend towards significance for productivity. Four features of bipolar disorder were also queried, reckless decisions, rapid speech, impulsivity, and irritability, and there was no significant difference for any of these items between groups. Two symptoms of ADHD were included, concentration trouble and ability to sit still. Those with FNSS reported less concentration trouble than peers and an equal ability to sit still.

Conclusion

Those with FNSS have multiple distinct traits including greater energy, pain tolerance, physical activity, ability to handle stress, hours working, and mental activity compared to unaffected family. When grouped together these traits can be titled “behavioral drive.” Further work will aim for validation of this scale in gene carriers and larger populations.

Support (If Any)

This work was supported by NIH grants NS099333, NS072360 and NS104782 to L.J.P. and Y-H.F., and by the William Bowes Neurogenetics Fund to L.J.P. and Y.H.F.
0179 Factor Analysis of Multidimensional Sleep Health Domains in Older Adults with Actigraphy: Results from the Einstein Aging Study
Authors: Ji Linying , Wallace Meredith , Master Lindsay , Schade Margeaux , Zhaoyang Ruixue , Derby Carol , Buxton Orfeu
Published: May 2022

Introduction

The concept of Sleep Health, based on self-reports in the RU-SATED model, has been recently extended using parameters derived from 4 days of actigraphy in a cohort of older adults, yielding a 5-component model. Using a longer actigraphy time series from a separate study, the current factor analysis evaluates and extends a theoretically-driven, multi-dimensional sleep health construct in older adults.

Methods

Participants (N=291, mean age=77.2 years, 33% males; 47% white, 40% Black, 13% Hispanic/others) enrolled in The Einstein Aging Study were included. A random subsample of 100 participants were used for exploratory factor analysis (EFA); data from the remaining participants (N=191) were used for confirmatory factor analyses (CFA). All 23 objective measures (mean 15.6 valid days +/-SD=1.2) were derived from wrist actigraphy, including 16 from the actigraphy summary statistics, and 7 from extended cosinor models. Fit of CFA models were evaluated by CFI, TLI, RMSEA, SRMR.

Results

Consistent with prior research, beta was not included in the final factor structure because of its low loading on all six factors. CFA was performed on each factor and model fitting results were satisfactory (CFI > 0.94, TLI >0.92, RMSEA 90% confidence interval ranges from 0 to 0.23, and SRMR <0.05). EFA identified 6 factors, 5 consistent with prior research, and a sixth hypothesized factor (Rhythmicity) not identified previously.REGULARITY (of sleep across days): standard deviations of four sleep measures; midpoint, sleep onset time, night total sleep time (TST), and 24h TST.ALERTNESS/Sleepiness (daytime): amplitude, napping (mins and #/day).TIMING: sleep onset, midpoint, wake-time (of nighttime sleep); up-Mesor, acrophase, down-Mesor.EFFICIENCY: sleep maintenance efficiency, wake after sleep onset.DURATION: night sleep duration, night TST, 24h sleep duration, 24h TST.RHYTHMICITY (pattern across days): mesor, alpha, and minimum.

Conclusion

These findings extend a multidimensional Sleep Health construct to include a Rhythmicity dimension when informed by extended objective data from older adults. Factors can be considered predictors of health outcomes, and targets for sleep interventions.

Support (If Any)

P01-AG003949, R01-AG062622, NIA-AG03949
0181 Characterizing Sleep Regularity from Actigraphy in Younger and Older Adolescents
Authors: Goodhines Patricia , Barker David , Gredvig-Ardito Caroline , Crowley Stephanie , Van Reen Eliza , LeBourgeois Monique , Carskadon Mary
Published: May 2022

Introduction

Many adolescents experience variable sleep timing and restricted duration attributable to biopsychosocial influences. The Sleep Regularity Index (SRI) captures inter-daily stability of sleep/wake intervals as the likelihood of being asleep/awake at consistent times day-to-day. The SRI may capture unique dimensions of adolescent sleep given the ability to capture highly variable sleep/wake timing (including napping); however, SRI’s relative role in maturational sleep processes remains unknown. This study characterizes the SRI and sleep correlates (bedtime, midpoint, risetime, duration, and efficiency) in younger and older adolescents, including age-based comparisons.

Methods

Cross-sectional data were drawn from two cohorts: 30 younger (ages 9-10 years; 13 female; 24 White) and 38 older (ages 15-16 years; 20 female; 26 White) adolescents. Participants provided 7 consecutive nights (M=6.93±0.36) of sleep diaries and actigraphy on a self-selected sleep schedule while attending school. SRI was calculated as the probability of being asleep/wake at two points 24-hours apart (Philips et al., 2017), with higher scores demonstrating more regular sleep across days.

Results

SRI scores and distributions were similar between younger (M=79±9, range=58-94) and older (M=80±7, range=64-91) adolescents (t[66]=-0.58, p=.56). On average, younger adolescents reported a bedtime of 21:41±31, midpoint of 02:14±30, risetime of 06:47±36, and sleep duration of 9.11±0.52 hours. In contrast, older peers reported a later bedtime of 22:46±41 (t[66]=-7.21, p<.001) and midpoint of 02:47±29 (t[66]=-4.66, p<.001), with consistent risetime 06:49±29 (t[66]=-0.17, p=.87), and thus shorter sleep duration of 8.06±0.70 hours (t[66]=6.84, p<.001). In both cohorts, SRI was correlated with less wake-time after sleep onset (rs=-.93 to -.83, ps<.001) and greater sleep efficiency (rs=.80-.93, ps<.001), but not sleep duration or timing (ps=.18-.62).

Conclusion

This adolescent sample demonstrated greater sleep/wake regularity compared to previous reports of college students and adolescents/young adults, supporting the hypothesis that SRI may be a proxy for regularity of other aspects of daily living (e.g., fixed school start times). Adolescent SRI appears to be independent of sleep duration (consistent with previous findings) and timing, suggesting that SRI captures a distinct dimension of sleep. This research team plans to proceed with longitudinal analysis to clarify developmental trends, further explicating the potential informative role of SRI.

Support (If Any)

NIH R01 AA013252 and P20 GM139743.
0184 Too Jittery to Sleep? Temporal Associations of Actigraphic Sleep and Caffeine in Adolescents
Authors: Mathew Gina , Reichenberger David , Master Lindsay , Buxton Orfeu , Chang Anne-Marie , Hale Lauren
Published: May 2022

Introduction

The majority of adolescents report consuming a caffeinated beverage on a typical day, which has been linked to poor sleep health in cross-sectional studies. However, it is unknown whether poor sleep predicts caffeine consumption, and/or whether caffeine consumption predicts poor sleep, particularly when sleep is measured objectively. The current study examined within- and between-person associations of actigraphic sleep dimensions with caffeinated beverage consumption in adolescents.

Methods

Data were collected from a micro-longitudinal substudy of the age 15 wave of the Fragile Families and Child Wellbeing Study (n=589). Adolescents wore a wrist-actigraphy device and completed daily surveys for approximately one week (mean=5.6 days). Daily surveys assessed sleep quality and caffeinated beverage consumption (0=no caffeine, 1=any caffeine). Separate mixed models assessed whether actigraphy-measured sleep duration, timing, maintenance efficiency, and subjective quality predicted next-day caffeinated beverage consumption within and between adolescents. Variability of sleep duration and timing (SD), sleep regularity index, and social jetlag were tested as additional between-person predictors. Lagged models tested whether daily caffeinated beverage consumption predicted sleep that night (n=458; mean=5.2 days).

Results

Between-person results showed that adolescents who had more variable actigraphic sleep duration (OR=1.21, p=.042) and sleep midpoint (OR=1.27, p=.045) had greater odds of consuming caffeinated beverages compared to others. Within-person results showed that on days when adolescents consumed ≥1 caffeinated beverage, they had later sleep onset by (b±SEM) 17±6 mins (p=.003) that night and later wake time by 19±7 mins (p= .011) the next morning, compared to days when they did not consume caffeine. Sleep duration, timing, maintenance efficiency, and subjective quality did not predict next-day caffeinated beverage consumption (all p>.10).

Conclusion

Greater variability in sleep duration and timing and later sleep timing are risk factors for poor emotional and cardiometabolic health. Curbing caffeinated beverage consumption may aid in the maintenance of regular sleep schedules and advance sleep timing in adolescents, potentially improving physical and psychological health.

Support (If Any)

R01HD073352
0199 Iris color predicts melanopsin-driven retinal responses in older but not younger individuals
Authors: Klevens Alison , Wescott Delainey , Drexler Scott , Gamlin Paul , Roecklein Kathryn
Published: May 2022

Introduction

The retina contains melanopsin-containing retinal ganglion cells, which underlie non-image forming responses to light. The Post-Illumination Pupil Response (PIPR) can assess melanopsin cell responsivity, with applications for sleep disorders, mood disorders, and circadian entrainment. Lighter pigmented irises allow more light to pass through the retina. The present study tested an association between the PIPR and iris pigmentation.

Methods

Participants (N=49) included seasonal depression (n=26) and never-depressed controls (n=23). Photos of participants’ irises were rated using both the Franssen (2008) scale, a set of 24 standardized iris photos, and the Mackey (2011) scale, a 9-category rating system. Red and blue stimuli 13.5 log photons/cm2/s were presented, and infrared pupillometry measured pupil diameter for 40 seconds. We used multilevel regression with a random intercept of participant to predict the PIPR from each iris rating system separately, controlling for age, gender, and circadian time of testing determined from Dim Light Melatonin Onset.

Results

Agreement between raters, calculated using Cohen's κ, was moderate for both scales (Franssen, κ=0.57, 95% CI: 0.42 to 0.71, p<0.001; Mackey, κ=0.67, 95% CI: 0.53 to 0.81, p<0.001). Bivariate correlations showed age was inversely associated with iris color: older individuals had lighter iris pigmentation. Analyses were therefore stratified by age (older >=31 years: n=24; younger <31 years, n=25). Greater retinal responsivity was associated with lighter iris pigmentation in the older sample (Mackey: unstandardized b=-0.016; SE=0.005; p=0.002; Franssen: unstandardized b=-0.006; SE=0.002, p=0.002), but not the younger sample (Mackey: unstandardized b=-0.0008; SE=0.003; p=0.770; Franssen: unstandardized b=-0.0009; SE=0.002, p=0.619). There was no effect of iris color on PIPR in the whole sample (p’s >0.13).

Conclusion

Iris color explained ~8% of variance in the PIPR, indicating that PIPR studies should recruit samples with similar distributions of iris pigmentation across conditions and ages, as this finding was only seen in the older sample with more individuals with lighter iris pigmentation. Future studies will test iris pigmentation by light exposure interactions on the PIPR. Light stimuli focused to a point on the pupil (i.e., Maxwellian) would eliminate variation in the amount of light incident on the retina due to iris pigmentation.

Support (If Any)

NIMH K.A.R. MH103303
0217 Is the Timing of the Endogenous Circadian Rhythm of Neurobehavioral Functioning Inherently Task-Dependent?
Authors: Muck Rachael , Hudson Amanda , Honn Kimberly , Van Dongen Hans
Published: May 2022

Introduction

Changes in waking neurobehavioral functioning (NF) over time are governed by homeostatic and circadian processes. It has been reported that peak circadian timing varies inherently between tasks, such that the optimal timing for NF would be task-dependent. Here we investigated this idea with a simulated shift work study protocol followed by a 24h constant routine (CR) protocol to experimentally and statistically separate the circadian from the homeostatic process.

Methods

N=13 healthy adults (ages 25.5±3.2y; 9 men) completed a 7-day/6-night in-laboratory study. They were randomized to a 3-day simulated day shift condition (n=7) with nighttime sleep (22:00–06:00) or a 3-day simulated night shift condition (n=6) with daytime sleep (10:00–18:00). They then underwent a 24h CR protocol, during which they stayed awake under constant behavioral and environmental conditions and blood was collected at 1–3h intervals for the assessment of dim light melatonin onset (DLMO). During scheduled wakefulness, subjects completed three functionally distinct NF tasks at ~2h intervals: the Karolinska Sleepiness Scale (KSS), Digit Symbol Substitution Test (DSST), and Psychomotor Vigilance Test (PVT). Data from these tasks taken during the CR protocol were analyzed with non-linear mixed-effects regression to separate endogenous circadian effects from the homeostatic process.

Results

Following simulated night shift, compared to simulated day shift, on average there was a modest, 1.4h (±0.8h SE) delay in DLMO (F1,11=3.68, p=0.082). As such, the simulated night shift condition produced a 10.6h shift in alignment of the homeostatic process relative to the circadian process. Regardless of prior shift condition, the peak of the circadian rhythm effect on NF occurred post-DLMO by 16.8h (±1.0h) for KSS, 15.9h (±1.4h) for DSST, and 18.6h (±1.0h) for PVT, which was not significantly different (F2,9=1.55, p=0.26).

Conclusion

As proof of principle, we studied three distinct NF assays, and found only small, non-significant differences between them in the timing of underlying circadian rhythmicity. While a larger sample could have yielded statistical significance in our comparison of circadian peak times, the small magnitude of the observed difference does not support the idea of inherent task-dependent differences in the timing of the endogenous circadian rhythm’s influence on NF.

Support (If Any)

CDMRP W81XWH-16-1-0319 and W81XWH-20-1-0442
0241 N3 Slow Wave Duration Correlates with Next-Day Savoring Behavior in Pre-pubertal Children
Authors: Alfano Candice , Baran Bengi , Palmer Cara
Published: May 2022

Introduction

Recent meta-analysis (Tomaso et al., 2020) indicates sleep loss to have more profound adverse effects on positive than negative emotion, and experimental studies in adults suggest disruption of slow wave sleep (SWS) in particular mediates these effects (Finan et al., 2015; 2017). In pre-pubertal children, greater SWS has been shown to protect against next day negative affect (Palmer & Alfano, 2017) as well as the development of depression years later (Silk et al., 2007); however specific emotion-based mechanisms underlying these effects have rarely been explored. Pre-pubertal years especially represent a critical developmental window for probing these relationships due to dramatic decreases in SWS that occur during pubertal transition (Carskadon & Dement, 2011).

Methods

We detected slow waves (0.5 – 4 Hz) during N3 sleep using an automated algorithm among N=18 pre-pubertal children (7-11 years) during a night of normal sleep in relation to next-day savoring; a positive emotion regulation strategy that includes using thoughts and actions to increase the intensity, duration, and appreciation of positive experiences and emotions. Healthy children without any psychiatric disorders completed a night of at-home PSG monitoring (10 hr sleep opportunity). The next morning at 11:00, children returned to the clinic for an in-lab emotional assessment. Before and during the assessment, children were told/reminded that they would be given a piece of chocolate to enjoy at the end of the assessment. After children consumed the chocolate, they were asked several questions about how much they ‘savored’ the experience. All analyses controlled for total sleep time on the PSG night and there were no differences in SWA based on gender.

Results

Results indicated that the average duration of detected N3 SWs (F3/F4) correlated significantly with the extent to which children enjoyed the chocolate overall (r =.50, p <.05), felt they did a good job enjoying the chocolate while eating it (r =.44-.49, p <.05) and looked forward to eating the chocolate during the assessment (r =.46-.50, p <.05).

Conclusion

Although preliminary, these novel findings suggest that greater intensity of SWS may have a modulatory effect on subsequent emotional responses to positive experiences/events, which could be protective for longer term affective health.

Support (If Any)
0263 Slow-wave Disruption Improves Irritability in Males with Major Depression: Potential Implications for Understanding the Impact of Sex Differences on Sleep and Neuroplasticity
Authors: Goldschmied Jennifer , Goldstein Elena , Palermo Emma , Costello Samantha , Games Margaux , Gehrman Philip
Published: May 2022

Introduction

Irritability has been proposed to be a core symptom of male-specific major depressive disorder (MDD), with a greater propensity to experiencing anger attacks and overreacting to minor annoyances compared to females with MDD. Males with MDD have also been shown to exhibit a pattern of reduced slow-wave sleep (SWS) that is not characteristic of females. Because SWS has been implicated in the homeostatic regulation of neuroplasticity, it is possible that this mood dysfunction in males is a result of SWS alterations via impairments in neuroplasticity. Therefore, in this study we aimed to manipulate SWS and examine its impact on mood.

Methods

19 individuals (11 F) with MDD were recruited for an ongoing clinical trial. Participants spent two nights in the sleep laboratory one week apart: a baseline (BL) night, and a night of slow-wave sleep disruption (SWD) utilizing auditory stimulation. Irritability was assessed in the morning following each overnight visit using the 5-item Brief Irritability Test (BITe). Repeated measures ANOVA was used to evaluate the change in irritability following SWD with condition (BL, SWD) as the within-subject factor and sex (M, F) as the between-subjects factor.

Results

Results revealed a significant Condition x Sex interaction (F(1,17) =10.1, p=.006) for change in irritability scores, with post-hoc t-tests indicating that males with MDD showed a significant decrease in irritability following SWD, t(7)=2.22, p<.05 while women showed a significant increase in irritability, t(10)=-2.34, p<.05. Changes in irritability were not found to be associated with changes in N3.

Conclusion

These data demonstrate that experimentally reducing SWS decreases irritability, a core symptom of mood dysfunction, in males with MDD. As SWS has been theorized to facilitate synaptic downscaling, these results may indicate that maintaining waking levels of synaptic strength in males improves depressive symptomatology and may point to the importance of sex differences in sleep and psychopathology. Moreover, these results suggest that the modulation of neuroplasticity via sleep manipulation may be a potential therapeutic target.

Support (If Any)

K23MH118580 (JG)
0275 Effect of acutely induced severe OSA on AD plasma biomarkers
Authors: Kam Korey , Jun Jonathan , Bubu Omonigho , Mullins Anna , Parekh Ankit , Gu Chenjuan , Pham Luu , Rapoport David , Ayappa Indu , Osorio Ricardo , Varga Andrew
Published: May 2022

Introduction

Obstructive sleep apnea (OSA) has been associated with Alzheimer’s disease (AD) progression but a causal relationship is unclear. We hypothesized that OSA can influence (AD) biomarkers including beta-amyloid (Aβ) and tau, as well as neural filament light chain (NfL).

Methods

To test this hypothesis, we examined plasma tau, NfL, Aβ42, and Aβ40 in a randomized crossover study of OSA vs. 3-night CPAP withdrawal in 30 subjects with severe OSA adherent to CPAP. We compared the overnight change in evening to morning plasma samples across the untreated night (off) versus CPAP treated night (on). Paired t-tests were used to compare measures across sleep conditions while hierarchical linear regression with difference in the overnight change of each biomarker between conditions were set as dependent variables with age and sex as covariates.

Results

Of the 30 subjects, mean age was 52 years and 27% were women. As expected, CPAP withdrawal caused sleep disruption and recurrence of underlying OSA. Sleep architecture measures including %N3 (Off: 6.1% [3.7-8.5], On: 15.1% [10.6-19.6], p<0.001), %REM (Off: 11.8% [8.8-14.7], On: 20.6% [18.3-22.9], p<0.001), and measures of breathing such as AHI4% (Off: 63/hr [54-72], On: 3/hr [2-4], p<0.001), SpO2 below 90% (Off: 20 min [14-26], On: 1 min [0-3], p<0.001), and SpO2 min (Off: 77% [74-80], On: 88% [86-90], p<0.001) were all significantly different in the untreated versus CPAP treated nights. Compared to CPAP treatment, the overnight change in NfL was increased relative to CPAP withdrawal while the overnight change in Aβ40 was decreased relative to CPAP withdrawal. No change was observed with tau or Aβ42. We found that difference in %N3 between the on- and off-CPAP conditions significantly explained an additional 15.7% of the variance beyond a base model including age and sex alone. No other difference in sleep architecture or apnea severity/hypoxemic burden metric significantly contributed to the variance in overnight change in Aβ40 between conditions, and we identified no significant predictors for variance in overnight change in NfL.

Conclusion

This study presents some of the first evidence for an effect of acute CPAP withdrawal on neurodegenerative and amyloid plasma biomarkers and implicates a role for N3 sleep in this effect.

Support (If Any)

AASMF Focus award, NIDDK P30DK072488, R01AG066870, K24HL109156
0289 Affect and Affective Personality during a Simulated First Night Shift
Authors: Ply Christopher , Pilcher June
Published: May 2022

Introduction

Shiftwork contributes to work-related stress and chronic partial sleep deprivation. A first night shift can be particularly problematical for many workers since they are required to adjust to working at night following a period of sleeping at night. Part of this adjustment involves emotional stability and reactivity including affect. The purpose of this study is to examine how affect and a related construct, affective personality, changes during a simulated first night shift.

Methods

Ninety undergraduate students, 60 males and 30 females (22.1 ± 3.0 years), participated in a simulated first night shift. As part of the night shift, the participants completed the PANAS test (using the cue: how they felt lately) assessing positive and negative affect four times during the simulated shift (6:30 pm, 10:30 pm, 3 am, 7:30 am). The PANAS data were grouped using median split values from the 6:30 pm survey into high and low positive and negative affect groups to represent four categories of affective personality (Self-Actualizing: high positive, low negative; High Affective: high positive, high negative; Self-Destructive: low positive, high negative; Low Affective: low positive, low negative).

Results

A 2x4 ANOVA found significant changes across the night for affect (p<.0001), a significant difference between positive and negative affect (p<.0001), and a significant interaction (p<.0001) with positive affect decreasing during the night but negative affect remaining stable. A Friedman Test found significant changes in affective personality across the night (p<.0001) with decreasing occurrences of Self-Actualizing and High Affective but increasing occurrences of Self-Destructive and Low Affective personality types.

Conclusion

These findings suggest that positive affect decreases during a first night shift which could reduce workers’ competence resulting in more performance errors and potential safety hazards. The change in affective personality suggests that these groupings are not personality traits but instead could be considered affective personality states. Managers and organizations should anticipate decreases in the positive affective personality states during a first night shift and may find that workers will be less adaptive and efficient.

Support (If Any)

This research funded in part by the Creative Inquiry Program at Clemson University.