Weeks Of Sleep Restriction Research Articles

Unethical decision making and sleep restriction: Experimental evidence

Insufficient sleep is costly to organizations (e.g., direct health costs, cognitive errors, accident risk, and lower labor productivity). In this current study, we examine another more hidden cost associated with insufficient sleep– unethical behaviors. Using a hybrid field/lab experimental approach, participants were randomly assigned to a week of sleep-restriction or well-rested sleep levels in their at-home (naturalistic) environment prior to decision making. We found that sleep restricted participants cheated significantly more in two honesty tasks, while anti-social choices were, surprisingly, not affected. Because sleep restriction promotes reduced deliberation, these results contribute to our understanding of the cognitive underpinnings of decision making. Importantly, these findings have practical implications to managers who want to reduce dishonesty in the workplace. For example, our results suggest that workplace health promotion programs focused on good sleep hygiene would additionally benefit the company in terms of indirectly promoting ethical conduct in the workplace.

Effect of Sleep Changes on Health-Related Quality of Life in Healthy Children

Little is known regarding the effect of poor sleep on health-related quality of life (HRQOL) in healthy children. To determine the effect of induced mild sleep deprivation on HRQOL in children without major sleep issues. This prespecified secondary analysis focused on HRQOL, a secondary outcome of the Daily Rest, Eating, and Activity Monitoring (DREAM) randomized crossover trial of children who underwent alternating weeks of sleep restriction and sleep extension and a 1-week washout in between. The DREAM trial intervention was administered at participants' homes between October 2018 and March 2020. Participants were 100 children aged 8 to 12 years who lived in Dunedin, New Zealand; had no underlying medical conditions; and had parent- or guardian-reported normal sleep (8-11 hours/night). Data were analyzed between July 4 and September 1, 2022. Bedtimes were manipulated to be 1 hour later (sleep restriction) and 1 hour earlier (sleep extension) than usual for 1 week each. Wake times were unchanged. All outcome measures were assessed during both intervention weeks. Sleep timing and duration were assessed using 7-night actigraphy. Children and parents rated the child's sleep disturbances (night) and impairment (day) using the 8-item Pediatric Sleep Disturbance and 8-item Sleep-Related Impairment scales of the Patient-Reported Outcomes Measurement Information System questionnaire. Child-reported HRQOL was assessed using the 27-item KIDSCREEN questionnaire with 5 subscale scores and a total score. Both questionnaires assessed the past 7 days at the end of each intervention week. Data were presented as mean differences and 95% CIs between the sleep restriction and extension weeks and were analyzed using intention to treat and an a priori difference in sleep of at least 30 minutes per night. The final sample comprised 100 children (52 girls [52%]; mean [SD] age, 10.3 [1.4] years). During the sleep restriction week, children went to sleep 64 (95% CI, 58-70) minutes later, and sleep offset (wake time) was 18 (95% CI, 13-24) minutes later, meaning that children received 39 (95% CI, 32-46) minutes less of total sleep per night compared with the sleep extension week in which the total sleep time was 71 (95% CI, 64-78) minutes less in the per-protocol sample analysis. Both parents and children reported significantly less sleep disturbance at night but greater sleep impairment during the day with sleep restriction. Significant standardized reductions in physical well-being (standardized mean difference [SMD], -0.28; 95% CI, -0.49 to -0.08), coping in a school environment (SMD, -0.26; 95% CI, -0.42 to -0.09), and total HRQOL score (SMD, -0.21; 95% CI, -0.34 to -0.08) were reported by children during sleep restriction, with an additional reduction in social and peer support (SMD, -0.24; 95% CI, -0.47 to -0.01) in the per-protocol sample analysis. Results of this secondary analysis of the DREAM trial indicated that even 39 minutes less of sleep per night for 1 week significantly reduced several facets of HRQOL in children. This finding shows that ensuring children receive sufficient good-quality sleep is an important child health issue. Australian New Zealand Clinical Trials Registry: ACTRN12618001671257.

P042 Actigraphy-derived sleep characteristics of healthy children who benefit the most from a sleep extension protocol

Abstract Introduction Although experimental manipulation of sleep can extend children’s sleep via earlier bedtimes, this is not always possible. We aimed to determine true sleep gains made with a one hour earlier bedtime, and which actigraphy variables at baseline predicted the best gains. Methods Secondary analysis within a randomised crossover trial (99 children; 49.5% female; mean age=10.3 years, range 8-12 years). Each child underwent one week of sleep restriction and extension in a random order (1h later or earlier bedtime respectively) separated by a one-week washout. Sleep data comparing baseline and extension weeks were analysed using linear or logistic regression, controlling for randomised order. Results The mean (SD) difference in total sleep time (TST) with sleep extension was 14.3 (44.1) min/night. Thirty-three percent extended their sleep by at least 30 min/night. At baseline, having lower sleep quantity (TST) and quality (efficiency, WASO, waking frequency) significantly predicted more sleep gain. For each 1 h lower TST at baseline, 29.7 min (95% CI 19.4, 40.1) more sleep was gained. At baseline, a TST below 8 h 49 min was the optimal cut-point to predict whether children could extend their sleep by at least 30 min/night (found in 40% of children). Adjusting for relevant demographics and sleep hygiene made little difference. Conclusion Children who slept less than 8 h 49 min/night obtained the most sleep gain from a 1 hour earlier bedtime maintained over a week. Maintenance over the longer term is unknown. Findings have implications for understanding the sleep requirements of children.

A Week of Sleep Restriction Does Not Affect Nighttime Glucose Concentration in Healthy Adult Males When Slow-Wave Sleep Is Maintained

The aim of this laboratory-based study was to examine the effect of sleep restriction on glucose regulation during nighttime sleep. Healthy males were randomly assigned to one of two conditions: 9 h in bed (n = 23, age = 24.0 year) or 5 h in bed (n = 18, age = 21.9 year). Participants had a baseline night with 9 h in bed (23:00–08:00 h), then seven nights of 9 h (23:00–08:00 h) or 5 h (03:00–08:00 h) in bed. Participants were mostly seated during the daytime but had three bouts of treadmill walking (4 km·h−1 for 10 min) at ~14:40 h, ~17:40 h, and ~20:40 h each day. On the baseline night and night seven, glucose concentration in interstitial fluid was assessed by using continuous glucose monitors, and sleep was assessed by using polysomnography. On night seven, compared to the 9 h group, the 5 h group obtained less total sleep (292 min vs. 465 min) and less REM sleep (81 min vs. 118 min), but their slow-wave sleep did not differ (119 min vs. 120 min), and their glucose concentration during sleep did not differ (5.1 mmol·L−1 vs. 5.1 mmol·L−1). These data indicate that sleep restriction does not cause elevated levels of circulating glucose during nighttime sleep when slow-wave sleep is maintained. In the future, it will be important to determine whether increased insulin is required to maintain circulating glucose at a normal level when sleep is restricted.

0299 The Effects of Chronic Sleep Restriction on Calorie and Macronutrient Intake

Abstract Introduction Chronic sleep restriction (CSR) has been associated with increased calorie intake and increased consumption of fats and carbohydrates, with inconsistent changes in protein. However, the majority of studies have either been observational field studies with no sleep intervention, or laboratory-based studies where food availability may not have reflected participants’ real-world choices. We hypothesized that calorie, fat, and carbohydrate intake would increase during a week of imposed CSR compared to a week of sleep satiation (SS) among individuals living in their home environment. Methods Twelve healthy participants (6 females) kept a fixed sleep-wake schedule, with a constant waketime, at home for four weeks (actigraphy confirmed compliance). During weeks one and three, participants maintained 9 hours in bed. During weeks two and four, participants were randomly assigned to experimental weeks of 5 and 9 hours of time-in-bed in a crossover design. Participants documented their food consumption during both experimental weeks using a picture-based meal logging application (MealLogger). Intake of calories and macronutrients were classified by two blinded evaluators. Descriptive statistics were calculated in SAS (Cary, NC). Results Participants averaged 4.43 ± 0.33 (SD) hours of sleep per night during CSR compared to 7.42 ± 0.42 hours during SS. Participants consumed a daily average of 1812 ± 672 kilocalories, 71 ± 31 grams of total fat, 217 ± 69 grams of carbohydrates, and 84 ± 40 grams of protein during CSR, compared to 1682 ± 514 kilocalories, 68 ± 23 grams of total fat, 198 ± 61 grams of carbohydrates, and 77 ± 32 grams of protein during SS. Conclusion Preliminary descriptive findings suggest that, on average, participants consumed more calories, from an increase in consumption of each macronutrient group, during a week of sleep restriction compared to a week of sleep satiation. Further analysis is needed to determine whether these differences are statistically different and to identify when calories were consumed in each of the experimental conditions. Support (If Any) Supported by the Force Health Protection Program of the Office of Naval Research (SAA2402925-1, Contract Award no. N0001418IP00050) and the NASA Airspace Operations and Safety Program, System-Wide Safety.

Staying vigilant during recurrent sleep restriction: dose-response effects of time-in-bed and benefits of daytime napping.

Study ObjectivesWe characterized vigilance deterioration with increasing time-on-task (ToT) during recurrent sleep restriction of different extents on simulated weekdays and recovery sleep on weekends, and tested the effectiveness of afternoon napping in ameliorating ToT-related deficits.MethodsIn the Need for Sleep studies, 194 adolescents (age = 15–19 years) underwent two baseline nights of 9-h time-in-bed (TIB), followed by two cycles of weekday manipulation nights and weekend recovery nights (9-h TIB). They were allocated 9 h, 8 h, 6.5 h, or 5 h of TIB for nocturnal sleep on weekdays. Three additional groups with 5 h or 6.5 h TIB were given an afternoon nap opportunity (5 h + 1 h, 5 h + 1.5 h, and 6.5 h + 1.5 h). ToT effects were quantified by performance change from the first 2 min to the last 2 min in a 10-min Psychomotor Vigilance Task administered daily.ResultsThe 9 h and the 8 h groups showed comparable ToT effects that remained at baseline levels throughout the protocol. ToT-related deficits were greater among the 5 h and the 6.5 h groups, increased prominently in the second week of sleep restriction despite partial recuperation during the intervening recovery period and diverged between these two groups from the fifth sleep-restricted night. Daytime napping attenuated ToT effects when nocturnal sleep restriction was severe (i.e. 5-h TIB/night), and held steady at baseline levels for a milder dose of nocturnal sleep restriction when total TIB across 24 h was within the age-specific recommended sleep duration (i.e. 6.5 h + 1.5 h).ConclusionsReducing TIB beyond the recommended duration significantly increases ToT-associated vigilance impairment, particularly during recurrent periods of sleep restriction. Daytime napping is effective in ameliorating such decrement.Clinical Trial RegistrationNCT02838095, NCT03333512, and NCT04044885.

Predicting vigilance vulnerability during 1 and 2 weeks of sleep restriction with baseline performance metrics.

We attempted to predict vigilance performance in adolescents during partial sleep deprivation using task summary metrics and drift diffusion modelling measures (DDM) derived from baseline vigilance performance. In the Need for Sleep studies, 57 adolescents (age = 15-19 years) underwent two baseline nights of 9-h time-in-bed (TIB), followed by two cycles of weekday sleep-restricted nights (5-h or 6.5-h TIB) and weekend recovery nights (9-h TIB). Vigilance was assessed daily with the Psychomotor Vigilance Task (PVT), with the number of lapses (response times ≥ 500 ms) as the primary outcome measure. The two DDM predictors were drift rate, which quantifies the speed of information accumulation and determines how quickly an individual derives a decision response, and non-decision time range, which indicates within-subject variation in physical, non-cognitive responding, e.g. motor actions. In the first week of sleep curtailment, faster accumulation of lapses was significantly associated with more lapses at baseline (p = .02), but not the two baseline DDM metrics: drift and non-decision time range (p > .07). On the other hand, faster accumulation of lapses and greater increment in reaction time variability from the first to the second week of sleep restriction were associated with lower drift (p < .007) at baseline. Among adolescents, baseline PVT lapses can predict inter-individual differences in vigilance vulnerability during 1 week of sleep restriction on weekdays, while drift more consistently predicts vulnerability during more weeks of sleep curtailment. Effects of Napping in Sleep-Restricted Adolescents, clinicaltrials.gov, NCT02838095. The Cognitive and Metabolic Effects of Sleep Restriction in Adolescents (NFS4), clinicaltrials.gov, NCT03333512.

Bone turnover marker responses to sleep restriction and weekend recovery sleep.

Prior data demonstrated three weeks of sleep restriction and concurrent circadian disruption uncoupled bone turnover markers (BTMs), indicating decreased bone formation and no change or increased bone resorption. The effect of insufficient sleep with or without ad libitum weekend recovery sleep on BTMs is unknown. BTMs were measured in stored serum from 20 healthy adults randomized to one of three study groups consisting of a control group (N=3 men; 9h/night) or one of two nocturnal sleep restriction groups in an inpatient laboratory environment. One Sleep Restriction group ("SR"; N=9; 4 women) had 5h sleep opportunity per night for nine nights. The other sleep restriction group had an opportunity for ad libitum Weekend Recovery sleep ("WR"; N=8; 4 women) after four nights of 5h sleep opportunity per night. Food intake was energy balanced at baseline and ad libitum thereafter. Fasted morning BTM levels and hourly 24h melatonin levels were obtained on study days 3 (baseline), 5 (after 1 night of sleep restriction for WR and SR), and 11 (after a sleep restricted workweek with weekend recovery sleep in WR or 7 nights of sleep restriction in SR). Linear mixed-effects modeling was used to examine the effect of study duration (e.g., change over time), study condition, age, and sex on BTMs. Pearson correlations were used to determine associations between changes in BTMs and changes in weight and morning circadian misalignment (i.e., duration of high melatonin levels after wake time). There was no significant difference between the three study groups in change over time (p ≥ 0.4 for interaction between assigned group and time for all BTMs), adjusted for age and sex. There was no significant change in N-terminal propeptide of procollagen type I (P1NP), osteocalcin, or C-telopeptide of type I collagen (CTX) from baseline to day 11 (all p ≥ 0.3). In women <25years old, there was a non-significant decline in P1NP from day 3 to day 5 (= -15.74±7.80ng/mL; p=0.06). Change in weight and morning circadian misalignment from baseline to day 11 were correlated with statistically non-significant changes in BTMs (all p ≤ 0.05). In this small secondary analysis, we showed that nine nights of prescribed sleep restriction with or without weekend recovery sleep and ad libitum food intake did not alter BTMs. It is possible that age, sex, weight change and morning circadian misalignment modify the effects of sleep restriction on bone metabolism.

Consecutive Nights of Moderate Sleep Loss Does Not Affect Mood in Healthy Young Males.

Sleep loss causes mood disturbance in non-clinical populations under severe conditions, i.e., two days/nights of sleep deprivation or a week of sleep restriction with 4–5 h in bed each night. However, the effects of more-common types of sleep loss on mood disturbance are not yet known. Therefore, the aim of this study was to examine mood disturbance in healthy adults over a week with nightly time in bed controlled at 5, 6, 7, 8 or 9 h. Participants (n = 115) spent nine nights in the laboratory and were given either 5, 6, 7, 8 or 9 h in bed over seven consecutive nights. Mood was assessed daily using the Profile of Mood States (POMS-2). Mixed-linear effects models examined the effect of time in bed on total mood disturbance and subscales of anger-hostility, confusion-bewilderment, depression-dejection, fatigue-inertia, tension-anxiety, vigour-activity and friendliness. There was no effect of time in bed on total mood disturbance (F(4, 110.42) = 1.31, p = 0.271) or any of the subscales except fatigue-inertia. Fatigue-inertia was higher in the 5 h compared with the 9 h time in bed condition (p = 0.012, d = 0.75). Consecutive nights of moderate sleep loss (i.e., 5–7 h) does not affect mood but does increase fatigue in healthy males.

139 Does Extraversion Predict Subjective Ratings of Sleepiness and Performance During Sleep Deprivation?

Abstract Introduction Repeated exposure to total sleep deprivation (TSD) within individuals has demonstrated task-specific, trait-like individual differences in cognitive impairment and subjective sleepiness. Research has suggested that introversion/extraversion may predict individual vulnerability to TSD. While previous analyses have found that extraversion does not reliably predict objective performance impairment on the psychomotor vigilance test (PVT) during TSD, it is not known whether extraversion may predict individuals’ subjective responses to TSD, including subjective ratings of sleepiness, fatigue, mood, performance, and effort. Methods N=21 healthy adults (aged 21-38; 9 women) completed three 4-day/3-night laboratory sessions – each including a baseline night, 36h TSD period, and recovery night –separated by at least 2 weeks each. Two of the sessions were preceded by a week of sleep extension (12h nightly sleep opportunities), while one session was preceded by a week of sleep restriction (6h nightly sleep opportunities), in randomized, counterbalanced order; only the sleep extension sessions are used here. Prior to the experiment, subjects filled out the Eysenck Personality Questionnaire (EPQ), which yielded an extraversion score; one subject did not complete the questionnaire and was excluded from analyses. Every 2h during TSD, subjects completed a 60min neurobehavioral test battery. At the beginning of the test battery, subjects completed the Karolinksa Sleepiness Scale (KSS) and visual analog scales of mood and fatigue (VAS-M and VAS-F). At the end of the test battery, subjects completed self-ratings of their performance (1–7 scale) and effort (1–4 scale). The relationship between extraversion and subjective scores after sleep deprivation (average over last 24h of 36h TSD period) relative to baseline (average over first 12h of TSD period) was analyzed using mixed-effects analysis of covariance, controlling for order, with a random effect over subjects on the intercept. Results No significant relationships were observed between extraversion and subjective estimates of sleepiness (KSS, p=0.45), fatigue (VAS-F, p=0.80), mood (VAS-M, p=0.14), performance (p=0.89), and effort (p=0.93). Conclusion These results indicate that extraversion is not a reliable predictor of trait-like individual differences in subjective vulnerability to 36h TSD. Support (if any) NASA grant NAG9-1161, CDMRP grant W81XWH-20-1-0442

The effect of sleep on public good contributions and punishment: Experimental evidence.

We investigate the effect of a full week of sleep restriction (SR) vs. well-restedness (WR) on contributions in a common public good experiment, the voluntary contributions mechanism (VCM). We examine the effect of sleep manipulation on decisions regarding both contributions and punishment of non-contributors. Actigraphy devices are used to confirm that our random assignment to sleep condition generates significant differences in objective nightly sleep duration and sleepiness. We find that when punishment is unavailable public good contributions do not differ by SR/WR assignment. When punishment is available, we find evidence that SR subjects contribute more than WR subjects, respond more to the availability of punishment than do WR subjects, and that the availability of punishment significantly increases the contributions of SR but not WR subjects. Yet SR subjects do not punish others more or less than WR subjects. Our main findings are robust when considering compliance and sample selection. However, some findings are not robust to an alternative but less objective sleep control measure that is based partly on participants' self-identified optimal sleep levels.

0303 Heart Rate and Systolic Blood Pressure Increase During Experimental Sleep Restriction

Abstract Introduction Experimental sleep restriction is associated with elevated daytime cardiac activity, including heart rate (HR) and blood pressure (BP). However, some studies have found changes in systolic (SBP) but not diastolic blood pressure (DBP) or found changes in neither. Although findings are mixed, there may be a dose-response effect of cumulative sleep loss on daytime cardiac activity, such that HR and BP increase above basal levels with additional nights of insufficient sleep. This study examined changes in cardiac activity during experimental sleep restriction. Methods We used multilevel models with random effects for individuals to analyze data from 15 healthy males (M=22.3 years old, SD=2.8) in an 11-day inpatient protocol consisting of three nights of 10-hour/night baseline sleep opportunity, five nights of sleep restriction (5-hour/night sleep opportunity), and then two recovery nights (10-hour/night sleep opportunity). HR and BP were measured approximately every two hours during wake. Results HR increased 0.75 beats/minute with each successive night of sleep restriction (SE=0.18, p&amp;lt;0.001). HR was 5.13 beats/minute higher during the recovery condition than during baseline or sleep restriction (SE=1.05, p&amp;lt;0.001). During sleep restriction only, HR was lower in the later morning and evening compared to the earliest morning timepoint of the day, F(10, 743)=10.44, p&amp;lt;0.001. SBP increased 0.33 mmHg following each successive night of sleep restriction (SE=0.16, p=0.041); however, SBP was only marginally higher during the sleep restriction condition than during baseline (b=1.90, SE=1.09, p=0.082). Conclusion Our findings suggest that HR and SBP increase with each additional day of experimental sleep restriction, even after accounting for diurnal effects on HR and SBP. HR did not recover to baseline levels following a night of recovery sleep, suggesting that longer recovery sleep may be necessary to recover from a week of sleep restriction. Support Grant UL1TR000127 (Chang PI), Clinical and Translational Science Institute; College of Health and Human Development at Pennsylvania State University.

Sleep Restriction With Circadian Disruption Negatively Alter Bone Turnover Markers in Women.

The purpose of this work is to determine whether an uncoupling of bone turnover markers (BTMs) occurs in women exposed to the combination of sleep restriction with circadian disruption (SRCD), as previously reported in men. Four bone biomarkers (N-terminal propeptide of type I procollagen [P1NP] and osteocalcin = bone formation; C-telopeptide [CTX] = bone resorption; sclerostin = bone formation inhibitor) were measured in bihourly samples over 24 hours at baseline and after approximately 3 weeks of sleep restriction (~5.6 hours of sleep/24 hours) with concurrent circadian disruption (SRCD, recurring 28-hour "day" in dim light). Maximum likelihood estimation in a repeated-measures model was used to assess the effects of SRCD and age on bone biomarkers. Five women were young (22 ± 2.8 years) and four were older (58 ± 1.8 years). Baseline bone biomarker levels did not differ by age (all P ≥ .07). Bone formation markers were lower after SRCD (estimate ± SEE, ΔP1NP = -9.5 ± 2.8 μg/L, P = .01; Δosteocalcin = -2.3 ± 0.9 ng/mL, P = .04). The P1NP decline was greater in young women (ΔP1NP = -12.9 ± 3.7 μg/L, P = .01). After SRCD, CTX was significantly higher in young women (0.182 ± 0.069 ng/mL, P = .04) but did not change in older women. These pilot data are similar to previous findings in men and suggest that SRCD negatively altered bone metabolism in women by decreasing markers of bone formation and, in young women, increasing a marker of bone resorption. If sustained, this pattern of BTM uncoupling may lead to bone loss and lower bone mineral density.

Impact of sleep restriction on affective functioning in adolescents with attention-deficit/hyperactivity disorder.

Shortened sleep and affective disturbances are both prevalent in adolescents with attention-deficit/hyperactivity disorder (ADHD), yet the causal link between these domains has not been examined. This study investigated whether shortened sleep duration is causally linked to affective functioning in adolescents with ADHD. Participants were 48 adolescents (75% male) aged 14-17years with ADHD who successfully completed a three-week sleep protocol using an experimental crossover design. The protocol included a phase stabilization week, followed, in randomized counterbalanced order, by one week of sleep restriction (6.5hr in bed) and one week of sleep extension (9.5hr in bed). Sleep was monitored with objective actigraphy, and all participants included in this study obtained ≥1hr actigraphy-measured sleep duration during extension compared to restriction. Parents and adolescents provided daily ratings of positive and negative affect during the extension and restriction conditions. Ratings of affect, internalizing symptoms, and emotion regulation were collected at laboratory visits conducted at the end of each week. Both parents and adolescents reported greater depressive symptoms and lower positive affect during restriction compared to extension. Parents also reported greater negative affect and emotion dysregulation among adolescents during sleep restriction than extension. No effects were found for parent- or adolescent-reported anxiety symptoms or for adolescent-reported emotion regulation or negative affect. Findings from this study provide the first evidence that shortened sleep duration is a causal contributor to the affect and mood disturbances frequently experienced by adolescents with ADHD, particularly as observed by parents. Targeting sleep may be important to reduce affective disturbances in adolescents with ADHD.

SAT-LB087 Combined Sleep Restriction and Circadian Disruption Negatively Alter Bone Turnover Markers in Women

Bone turnover markers (BTMs) display diurnal rhythms. Studies in rats and men suggest sleep restriction and circadian disruption are detrimental to bone metabolism. The effects of sleep and circadian disruption on BTMs in women are unknown. We hypothesized that cumulative sleep restriction and concurrent circadian disruption would decrease P1NP levels in women and that the magnitude of decline would be greater in younger compared to older women, as previously reported in men (JCEM 102(10) 2017). Four bone biomarkers (P1NP and osteocalcin = bone formation; C-telopeptide (CTX) = bone resorption; sclerostin = osteocyte protein/bone formation inhibitor) were measured in nine women from bihourly samples over 24h at baseline and after ~3 weeks of sleep restriction (~5.6h sleep/24h) with concurrent circadian disruption (recurring 28-h ‘day’ in dim light), termed SRCD. Maximum likelihood estimation in a repeated measures model was used to assess the effects of SRCD and age on bone biomarkers. A cosinor model was used to estimate circadian rhythm. Data are presented as estimate ± SEE. Five women were younger (avg 22 yrs, range 18-24) and four were older (avg 58 yrs, range 56-60). Baseline bone biomarker levels did not differ significantly by age (all p > 0.07) and were 51.6 ± 4.3 μg/L (P1NP), 0.686 ± 0.042 ng/mL (CTX), 21.8 ± 1.4 ng/mL (osteocalcin) and 20.5 ± 1.1 pmol/L (sclerostin). CTX was the only biomarker with a significant diurnal rhythm (p < 0.001). The average ± SD duration of SRCD exposure was 22 ± 2 calendar days. P1NP was significantly lower after SRCD in the group (Δ = -17.9% or -9.2 ± 2.8 μg/L, p = 0.02) and in the younger women (Δ = -22.3% or -12.5 ± 3.7 μg/L, p = 0.01). For the group, SRCD had no significant effect on CTX (Δ = 9.1% or 0.063 ± 0.052 ng/mL, p = 0.27), sclerostin (Δ = 15.9% or 3.3 ± 1.5 pmol/L, p = 0.07), or osteocalcin (Δ = -9.4% or -2.1 ± 0.9 ng/mL, p = 0.06); whereas after SRCD, CTX was significantly higher in younger women (Δ = 33.0% or 0.182 ± 0.069 ng/mL, p = 0.04) and sclerostin was significantly higher in older women (Δ = 24.9% or 5.4 ± 2.2 pmol/L, p = 0.05). The small sample size precludes definitive conclusions, particularly regarding age effects. Environmental differences compared to home (e.g., diet, activity) may have also contributed to the observed changes. However, these preliminary data suggest that cumulative sleep restriction and concurrent circadian disruption negatively altered bone metabolism in women by decreasing a marker of bone formation (P1NP) and, in younger women, also increasing a marker of bone resorption (CTX). Similar to previous findings in men, the detrimental impact of cumulative sleep restriction and concurrent circadian disruption on bone metabolism was of greater magnitude in younger women. If sustained, this pattern of BTM change may lead to bone loss and lower bone mineral density over time. Disclosures: See book Funding: K23; Center for Women’s Health Research Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Shortened Sleep Duration Causes Sleepiness, Inattention, and Oppositionality in Adolescents With Attention-Deficit/Hyperactivity Disorder: Findings From a Crossover Sleep Restriction/Extension Study.

Although poor sleep is often reported in adolescents with attention-deficit/hyperactivity disorder (ADHD), prior studies have been correlational. This study investigated whether sleep duration is causally linked to sleepiness, inattention, and behavioral functioning in adolescents with ADHD. A total of 72 adolescents (aged 14-17 years) entered a 3-week sleep protocol using an experimental crossover design. The protocol included a phase stabilization week, followed in randomized counterbalanced order by 1 week of sleep restriction (6.5 hours) and 1 week of sleep extension (9.5 hours). Sleep was monitored with actigraphy and daily sleep diaries, with laboratory visits at the end of each week. Analyses included 48 adolescents who had complete actigraphy data and successfully completed the sleep protocol (defined a priori as obtaining≥1 hour actigraphy-measured sleep duration during extension compared to restriction). Parent and adolescent ratings of daytime sleepiness, ADHD symptoms, sluggish cognitive tempo (SCT), and oppositional behaviors were the primary measures. The A-X Continuous Performance Test (CPT) was a secondary measure. Compared to the extended sleep week, parents reported more inattentive and oppositional symptoms during the restricted sleep week. Both parents and adolescents reported more SCT symptoms and greater daytime sleepiness during restriction compared to extension. Adolescents reported less hyperactivity-impulsivity during sleep restriction than extension. No effects were found for parent-reported hyperactivity-impulsivity, adolescent-reported ADHD inattention, or CPT performance. This study provides the first evidence that sleep duration is a causal contributor to daytime behaviors in adolescents with ADHD. Sleep may be an important target for intervention in adolescents with ADHD. Cognitive and Behavioral Effects of Sleep Restriction in Adolescents With ADHD; https://clinicaltrials.gov/; NCT02732756.

Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization.

Chronic pain conditions are highly comorbid with insufficient sleep. While the mechanistic relationships between the 2 are not understood, chronic insufficient sleep may be 1 pathway through which central pain-modulatory circuits deteriorate, thereby contributing to chronic pain vulnerability over time. To test this hypothesis, an in-laboratory model of 3 weeks of restricted sleep with limited recovery (5 nights of 4-hour sleep per night followed by 2 nights of 8-hour sleep per night) was compared with 3 weeks of 8-hour sleep per night (control protocol). Seventeen healthy adults participated, with 14 completing both 3-week protocols. Measures of spontaneous pain, heat-pain thresholds, cold-pain tolerance (measuring habituation to cold over several weeks), and temporal summation of pain (examining the slope of pain ratings during cold water immersion) were assessed at multiple points during each protocol. Compared with the control protocol, participants in the sleep-restriction protocol experienced mild increases in spontaneous pain (P < 0.05). Heat-pain thresholds decreased after the first week of sleep restriction (P < 0.05) but normalized with longer exposure to sleep restriction. By contrast, chronic exposure to restricted sleep was associated with decreased habituation to, and increased temporal summation in response to cold pain (both P < 0.05), although only in the past 2 weeks of the sleep-restriction protocol. These changes may reflect abnormalities in central pain-modulatory processes. Limited recovery sleep did not completely resolve these alterations in pain-modulatory processes, indicating that more extensive recovery sleep is required. Results suggest that exposure to chronic insufficient sleep may increase vulnerability to chronic pain by altering processes of pain habituation and sensitization.

The King–Devick test as a predictor of cognitive effects after chronic partial sleep restriction: a pilot study

The King–Devick test (K–D) is sensitive to the effects of acute sleep deprivation. It remains unclear whether the K–D is sensitive to the effects of chronic partial sleep restriction (SR). K–D performance was compared in a college student sample at baseline and after a week of SR. Subjects also completed measures of attention, processing speed, working memory, vocabulary and verbal reasoning. Subjects performed worse relative to their baselines on the K–D than previous test–retest reliability literature indicates, and worse on tests of attention, processing speed and working memory. Verbal reasoning and vocabulary were unaffected. An association between K–D performance and sleep duration during SR trended toward significance. These results provide initial support for the sensitivity of the K–D to SR.

Daily Rhythms of Hunger and Satiety in Healthy Men during One Week of Sleep Restriction and Circadian Misalignment.

The impact of sleep restriction on the endogenous circadian rhythms of hunger and satiety were examined in 28 healthy young men. Participants were scheduled to 2 × 24-h days of baseline followed by 8 × 28-h days of forced desynchrony during which sleep was either moderately restricted (equivalent to 6 h in bed/24 h; n = 14) or severely restricted (equivalent to 4 h in bed/24 h; n = 14). Self-reported hunger and satisfaction were assessed every 2.5 h during wake periods using visual analogue scales. Participants were served standardised meals and snacks at regular intervals and were not permitted to eat ad libitum. Core body temperature was continuously recorded with rectal thermistors to determine circadian phase. Both hunger and satiety exhibited a marked endogenous circadian rhythm. Hunger was highest, and satiety was lowest, in the biological evening (i.e., ~17:00–21:00 h) whereas hunger was lowest, and satiety was highest in the biological night (i.e., 01:00–05:00 h). The results are consistent with expectations based on previous reports and may explain in some part the decrease in appetite that is commonly reported by individuals who are required to work at night. Interestingly, the endogenous rhythms of hunger and satiety do not appear to be altered by severe—as compared to moderate—sleep restriction.

Sleep Restriction and Time‐Of‐Day Impacts on Simple Social Interaction

Simple bargaining games are the foundation of more complex social interactions necessary for healthy relationships and well‐functioning societies. Neuroscience research has shown that high‐level deliberative thinking processes are necessary for social‐decision making - it seems cognitively less demanding to be greedy or to mistrust. In this paper, our focus is on how commonly‐experienced adverse sleep states, which are known to harm deliberative thinking, impact outcomes in the classic simple bargaining games (ultimatum, dictator, and trust games). Specifically, we experimentally manipulate sleep states of 184 young‐adult subjects who took part in a 3 week experimental protocol.Subjects were administered each game twice: once after a full week of sleep restriction and once after a full week of well‐rested sleep levels. Subjects were also randomly assigned to early morning (7:30 am) or later evening (10:00 pm) sessions to manipulate the optimality of the time‐of‐day of the decisions. We find a robust result of increased greed, reduced trust, and reduced trustworthiness following sleep restriction, after controlling for demographics and session indicators. We find no significant direct impact of circadian timing on decisions for these tasks. However, the mediating variable for these sleep manipulation effects is subjective sleepiness, and both sleep restriction and suboptimal circadian timing significantly increase self‐reported sleepiness. These results are consistent with the hypothesis that increased sleepiness reduces the relative input of deliberate thinking in social interactions.