Compulsion or chronobiology? A case of severe obsessive-compulsive disorder treated with cognitive-behavioral therapy augmented with chronotherapy.

PubMed

Coles, Meredith E; Sharkey, Katherine M

2011-06-15

Individuals with treatment-resistant obsessive compulsive disorder (OCD) have elevated rates of delayed sleep phase. This report describes a patient with severe OCD who had failed prior trials of pharmacotherapy and psychotherapy, and whose symptoms were associated with delayed bedtimes and delays in the time she initiated her nighttime compulsions. Case report. A 54 year-old woman with OCD kept sleep/symptom logs as an adjunct to traditional cognitive-behavioral therapy for OCD. At presentation, she reported habitual bedtime = 06:00, wake time = 13:00, sleep latency ' 5 min, and total sleep time = 6.5-7.5 h. Later time of initiating her compulsions was associated with longer time performing the compulsions (r = 0.86, p < 0.001). Cognitive-behavioral therapy with adjunctive chronotherapy was associated with substantial improvement. OCD patients with nighttime compulsions may receive light exposure that results in delayed sleep times/circadian phase. Chronotherapy may enhance outcomes for refractory OCD patients, particularly those who perform compulsions at night.

Bright-light mask treatment of delayed sleep phase syndrome.

PubMed

Cole, Roger J; Smith, Julian S; Alcalá, Yvonne C; Elliott, Jeffrey A; Kripke, Daniel F

2002-02-01

We treated delayed sleep phase syndrome (DSPS) with an illuminated mask that provides light through closed eyelids during sleep. Volunteers received either bright white light (2,700 lux, n = 28) or dim red light placebo (0.1 lux, n = 26) for 26 days at home. Mask lights were turned on (< 0.01 lux) 4 h before arising, ramped up for 1 h, and remained on at full brightness until arising. Volunteers also attempted to systematically advance sleep time, avoid naps, and avoid evening bright light. The light mask was well tolerated and produced little sleep disturbance. The acrophase of urinary 6-sulphatoxymelatonin (6-SMT) excretion advanced significantly from baseline in the bright group (p < 0.0006) and not in the dim group, but final phases were not significantly earlier in the bright group (ANCOVA ns). Bright treatment did produce significantly earlier phases, however, among volunteers whose baseline 6-SMT acrophase was later than the median of 0602 h (bright shift: 0732-0554 h, p < 0.0009; dim shift: 0746-0717 h, ns; ANCOVA p = 0.03). In this subgroup, sleep onset advanced significantly only with bright but not dim treatment (sleep onset shift: bright 0306-0145 h, p < 0.0002; dim 0229-0211 h, ns; ANCOVA p < .05). Despite equal expectations at baseline, participants rated bright treatment as more effective than dim treatment (p < 0.04). We conclude that bright-light mask treatment advances circadian phase and provides clinical benefit in DSPS individuals whose initial circadian delay is relatively severe.

Effects of partial circadian adjustments on sleep and vigilance quality during simulated night work.

PubMed

Chapdelaine, Simon; Paquet, Jean; Dumont, Marie

2012-08-01

In most situations, complete circadian adjustment is not recommended for night workers. With complete adjustment, workers experience circadian misalignment when returning on a day-active schedule, causing repeated circadian phase shifts and internal desynchrony. For this reason, partial circadian realignment was proposed as a good compromise to stabilize internal circadian rhythms in night shift workers. However, the extent of partial circadian adjustment necessary to improve sleep and vigilance quality is still a matter of debate. In this study, the effects of small but statistically significant partial circadian adjustments on sleep and vigilance quality were assessed in a laboratory simulation of night work to determine whether they were also of clinical significance. Partial adjustments obtained by phase delay or by phase advance were quantified not only by the phase shift of dim light salivary melatonin onset, but also by the overlap of the episode of melatonin production with the sleep-wake cycle adopted during simulated night work. The effects on daytime sleep and night-time vigilance quality were modest. However, they suggest that even small adjustments by phase delay may decrease the accumulation of sleep debt, whereas the advance strategy improves subjective alertness and mood during night work. Furthermore, absolute phase shifts, by advance or by delay, were associated with improved subjective alertness and mood during the night shift. These strategies need to be tested in the field, to determine whether they can be adapted to real-life situations and provide effective support to night workers. © 2012 European Sleep Research Society.

Dark goggles and bright light improve circadian rhythm adaptation to night-shift work.

PubMed

Eastman, C I; Stewart, K T; Mahoney, M P; Liu, L; Fogg, L F

1994-09-01

We compared the contributions of bright light during the night shift and dark goggles during daylight for phase shifting the circadian rhythm of temperature to realign with a 12-hour shift of sleep. After 10 baseline days there were 8 night-work/day-sleep days. Temperature was continuously recorded from 50 subjects. There were four groups in a 2 x 2 design: light (bright, dim), goggles (yes, no). Subjects were exposed to bright light (about 5,000 lux) for 6 hours on the first 2 night shifts. Dim light was < 500 lux. Both bright light and goggles were significant factors for producing circadian rhythm phase shifts. The combination of bright light plus goggles was the most effective, whereas the combination of dim light and no goggles was the least effective. The temperature rhythm either phase advanced or phase delayed when it aligned with daytime sleep. However, when subjects did not have goggles only phase advances occurred. Goggles were necessary for producing phase delays. The most likely explanation is that daylight during the travel-home window after a night shift inhibits phase-delay shifts, and goggles can prevent this inhibition. Larger temperature-rhythm phase shifts were associated with better subjective daytime sleep, less subjective fatigue and better mood.

Improvement of a patient's circadian rhythm sleep disorders by aripiprazole was associated with stabilization of his bipolar illness.

PubMed

Tashiro, Tetsuo

2017-04-01

Splitting of the behavioural activity phase has been found in nocturnal rodents with suprachiasmatic nucleus (SCN) coupling disorder. A similar phenomenon was observed in the sleep phase in the diurnal human discussed here, suggesting that there are so-called evening and morning oscillators in the SCN of humans. The present case suffered from bipolar disorder refractory to various treatments, and various circadian rhythm sleep disorders, such as delayed sleep phase, polyphasic sleep, separation of the sleep bout resembling splitting and circabidian rhythm (48 h), were found during prolonged depressive episodes with hypersomnia. Separation of sleep into evening and morning components and delayed sleep-offset (24.69-h cycle) developed when lowering and stopping the dose of aripiprazole (APZ). However, resumption of APZ improved these symptoms in 2 weeks, accompanied by improvement in the patient's depressive state. Administration of APZ may improve various circadian rhythm sleep disorders, as well as improve and prevent manic-depressive episodes, via augmentation of coupling in the SCN network. © 2017 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

Individually tailored light intervention through closed eyelids to promote circadian alignment and sleep health

PubMed Central

Figueiro, Mariana G.

2016-01-01

Background Light is most effective at changing the timing of the circadian clock when applied close to the core body temperature minimum. The present study investigated, in a home setting, if individually tailored light treatment using flashing blue light delivered through closed eyelids during the early part of the sleep period delayed circadian phase and sleep in a population of healthy older adults and in those suffering from early awakening insomnia. Methods Twenty-eight participants (9 early awakening insomniacs) completed an 8-week, within-subjects study. Twice, participants collected data during two baseline weeks and one intervention week. During the intervention week, participants wore a flashing blue (active) or a flashing red (control) light mask during sleep. Light was expected to delay circadian phase. Saliva samples for dim light melatonin onset (DLMO) were collected at the end of each baseline and intervention week. Wrist actigraphy and Daysimeter, a calibrated light and activity meter, data were collected during the entire study. Results Compared to baseline, flashing blue light, but not flashing red light, significantly (p<0.05) delayed DLMO. The mean ± standard deviation phase shift (minutes) was 0:06 ± 0:30 for the flashing red light and 0:34 ± 0:30 for the flashing blue light. Compared to Day 1, sleep start times were significantly delayed (by approximately 46 minutes) at Day 7 after the flashing blue light. The light intervention did not affect sleep efficiency. Conclusions The present study demonstrated the feasibility of using light through closed eyelids during sleep for promoting circadian alignment and sleep health. PMID:26985450

Physical exercise accelerates reentrainment of human sleep-wake cycle but not of plasma melatonin rhythm to 8-h phase-advanced sleep schedule.

PubMed

Yamanaka, Yujiro; Hashimoto, Satoko; Tanahashi, Yusuke; Nishide, Shin-Ya; Honma, Sato; Honma, Ken-Ichi

2010-03-01

Effects of timed physical exercise were examined on the reentrainment of sleep-wake cycle and circadian rhythms to an 8-h phase-advanced sleep schedule. Seventeen male adults spent 12 days in a temporal isolation facility with dim light conditions (<10 lux). The sleep schedule was phase-advanced by 8 h from their habitual sleep times for 4 days, which was followed by a free-run session for 6 days, during which the subjects were deprived of time cues. During the shift schedule, the exercise group (n = 9) performed physical exercise with a bicycle ergometer in the early and middle waking period for 2 h each. The control group (n = 8) sat on a chair at those times. Their sleep-wake cycles were monitored every day by polysomnography and/or weight sensor equipped with a bed. The circadian rhythm in plasma melatonin was measured on the baseline day before phase shift: on the 4th day of shift schedule and the 5th day of free-run. As a result, the sleep-onset on the first day of free-run in the exercise group was significantly phase-advanced from that in the control and from the baseline. On the other hand, the circadian melatonin rhythm was significantly phase-delayed in the both groups, showing internal desynchronization of the circadian rhythms. The sleep-wake cycle resynchronized to the melatonin rhythm by either phase-advance or phase-delay shifts in the free-run session. These findings indicate that the reentrainment of the sleep-wake cycle to a phase-advanced schedule occurs independent of the circadian pacemaker and is accelerated by timed physical exercise.

Clinical Practice Guideline for the Treatment of Intrinsic Circadian Rhythm Sleep-Wake Disorders: Advanced Sleep-Wake Phase Disorder (ASWPD), Delayed Sleep-Wake Phase Disorder (DSWPD), Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD), and Irregular Sleep-Wake Rhythm Disorder (ISWRD). An Update for 2015

PubMed Central

Auger, R. Robert; Burgess, Helen J.; Emens, Jonathan S.; Deriy, Ludmila V.; Thomas, Sherene M.; Sharkey, Katherine M.

2015-01-01

A systematic literature review and meta-analyses (where appropriate) were performed and the GRADE approach was used to update the previous American Academy of Sleep Medicine Practice Parameters on the treatment of intrinsic circadian rhythm sleep-wake disorders. Available data allowed for positive endorsement (at a second-tier degree of confidence) of strategically timed melatonin (for the treatment of DSWPD, blind adults with N24SWD, and children/ adolescents with ISWRD and comorbid neurological disorders), and light therapy with or without accompanying behavioral interventions (adults with ASWPD, children/adolescents with DSWPD, and elderly with dementia). Recommendations against the use of melatonin and discrete sleep-promoting medications are provided for demented elderly patients, at a second- and first-tier degree of confidence, respectively. No recommendations were provided for remaining treatments/ populations, due to either insufficient or absent data. Areas where further research is needed are discussed. Citation: Auger RR, Burgess HJ, Emens JS, Deriy LV, Thomas SM, Sharkey KM. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders: advanced sleep-wake phase disorder (ASWPD), delayed sleep-wake phase disorder (DSWPD), non-24-hour sleep-wake rhythm disorder (N24SWD), and irregular sleep-wake rhythm disorder (ISWRD). An update for 2015. J Clin Sleep Med 2015;11(10):1199–1236. PMID:26414986

Sleep patterns in Amazon rubber tappers with and without electric light at home.

PubMed

Moreno, C R C; Vasconcelos, S; Marqueze, E C; Lowden, A; Middleton, B; Fischer, F M; Louzada, F M; Skene, D J

2015-09-11

Today's modern society is exposed to artificial electric lighting in addition to the natural light-dark cycle. Studies assessing the impact of electric light exposure on sleep and its relation to work hours are rare due to the ubiquitous presence of electricity. Here we report a unique study conducted in two phases in a homogenous group of rubber tappers living and working in a remote area of the Amazon forest, comparing those living without electric light (n = 243 in first phase; n = 25 in second phase) to those with electric light at home (n = 97 in first phase; n = 17 in second phase). Questionnaire data (Phase 1) revealed that rubber tappers with availability of electric light had significantly shorter sleep on work days (30 min/day less) than those without electric light. Analysis of the data from the Phase 2 sample showed a significant delay in the timing of melatonin onset in workers with electric light compared to those without electric light (p < 0.01). Electric lighting delayed sleep onset and reduced sleep duration during the work week and appears to interfere with alignment of the circadian timing system to the natural light/dark cycle.

Association between sleep stages and hunger scores in 36 children.

PubMed

Arun, R; Pina, P; Rubin, D; Erichsen, D

2016-10-01

Childhood obesity is a growing health challenge. Recent studies show that children with late bedtime and late awakening are more obese independent of total sleep time. In adolescents and adults, a delayed sleep phase has been associated with higher caloric intake. Furthermore, an adult study showed a positive correlation between REM sleep and energy balance. This relationship has not been demonstrated in children. However, it may be important as a delayed sleep phase would increase the proportion of REM sleep. This study investigated the relationship between hunger score and sleep physiology in a paediatric population. Thirty-six patients referred for a polysomnogram for suspected obstructive sleep apnoea were enrolled in the study. Sleep stages were recorded as part of the polysomnogram. Hunger scores were obtained using a visual analogue scale. Mean age was 9.6 ± 3.5 years. Mean hunger scores were 2.07 ± 2.78. Hunger scores were positively correlated with percentage of total rapid eye movement (REM) sleep (r = 0.438, P < 0.01) and REM sleep duration in minutes (r = 0.471, P < 0.05). Percentage slow wave sleep (SWS) was negatively correlated with hunger score (r = -0.360, P < 0.05). There were no correlations between age, sex, body mass index percentiles, apnoea-hypopnoea index, total sleep time, sleep efficiency, sleep onset latency, stage 2 sleep duration and hunger scores. These findings suggest that delayed bedtime, which increases the proportion of REM sleep and decreases the proportion of SWS, results in higher hunger levels in children. © 2015 World Obesity.

Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial.

PubMed

Sletten, Tracey L; Magee, Michelle; Murray, Jade M; Gordon, Christopher J; Lovato, Nicole; Kennaway, David J; Gwini, Stella M; Bartlett, Delwyn J; Lockley, Steven W; Lack, Leon C; Grunstein, Ronald R; Rajaratnam, Shantha M W

2018-06-01

Delayed Sleep-Wake Phase Disorder (DSWPD) is characterised by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time for daytime commitments. Although there are published therapeutic guidelines for the administration of melatonin for DSWPD, to our knowledge, randomised controlled trials are lacking. This trial tested the efficacy of 0.5 mg melatonin, combined with behavioural sleep-wake scheduling, for improving sleep initiation in clinically diagnosed DSWPD patients with a delayed endogenous melatonin rhythm relative to patient-desired (or -required) bedtime (DBT). This randomised, placebo-controlled, double-blind clinical trial was conducted in an Australian outpatient DSWPD population. Following 1-wk baseline, clinically diagnosed DSWPD patients with delayed melatonin rhythm relative to DBT (salivary dim light melatonin onset [DLMO] after or within 30 min before DBT) were randomised to 4-wk treatment with 0.5 mg fast-release melatonin or placebo 1 h before DBT for at least 5 consecutive nights per week. All patients received behavioural sleep-wake scheduling, consisting of bedtime scheduled at DBT. The primary outcome was actigraphic sleep onset time. Secondary outcomes were sleep efficiency in the first third of time in bed (SE T1) on treatment nights, subjective sleep-related daytime impairment (Patient Reported Outcomes Measurement Information System [PROMIS]), PROMIS sleep disturbance, measures of daytime sleepiness, clinician-rated change in illness severity, and DLMO time. Between September 13, 2012 and September 1, 2014, 307 participants were registered; 116 were randomised to treatment (intention-to-treat n = 116; n = 62 males; mean age, 29.0 y). Relative to baseline and compared to placebo, sleep onset occurred 34 min earlier (95% confidence interval [CI] -60 to -8) in the melatonin group. SE T1 increased; PROMIS sleep-related impairment, PROMIS sleep disturbance, insomnia severity, and functional disability decreased; and a greater proportion of patients showed more than minimal clinician-rated improvement following melatonin treatment (52.8%) compared to placebo (24.0%) (P < 0.05). The groups did not differ in the number of nights treatment was taken per protocol. Post-treatment DLMO assessed in a subset of patients (n = 43) was not significantly different between groups. Adverse events included light-headedness, daytime sleepiness, and decreased libido, although rates were similar between treatment groups. The clinical benefits or safety of melatonin with long-term treatment were not assessed, and it remains unknown whether the same treatment regime would benefit patients experiencing DSWPD sleep symptomology without a delay in the endogenous melatonin rhythm. In this study, melatonin treatment 1 h prior to DBT combined with behavioural sleep-wake scheduling was efficacious for improving objective and subjective measures of sleep disturbances and sleep-related impairments in DSWPD patients with delayed circadian phase relative to DBT. Improvements were achieved largely through the sleep-promoting effects of melatonin, combined with behavioural sleep-wake scheduling. This trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000425897.

Can Circadian Dysregulation Exacerbate Migraines?

PubMed

Ong, Jason C; Taylor, Hannah L; Park, Margaret; Burgess, Helen J; Fox, Rina S; Snyder, Sarah; Rains, Jeanetta C; Espie, Colin A; Wyatt, James K

2018-05-04

This observational pilot study examined objective circadian phase and sleep timing in chronic migraine (CM) and healthy controls (HC) and the impact of circadian factors on migraine frequency and severity. Sleep disturbance has been identified as a risk factor in the development and maintenance of CM but the biological mechanisms linking sleep and migraine remain largely theoretical. Twenty women with CM and 20 age-matched HC completed a protocol that included a 7 day sleep assessment at home using wrist actigraphy followed by a circadian phase assessment using salivary melatonin. We compared CM vs HC on sleep parameters and circadian factors. Subsequently, we examined associations between dim-light melatonin onset (DLMO), the midpoint of the sleep episode, and the phase angle (time from DLMO to sleep midpoint) with the number of migraine days per month and the migraine disability assessment scale (MIDAS). CM and HC did not differ on measures of sleep or circadian phase. Within the CM group, more frequent migraine days per month was significantly correlated with DLMO (r = .49, P = .039) and later sleep episode (r = .47, P = .037). In addition, a greater phase angle (ie, circadian misalignment) was significantly correlated with more severe migraine-related disability (r = .48, P = .042). These relationships remained significant after adjusting for total sleep time. This pilot study revealed that circadian misalignment and delayed sleep timing are associated with higher migraine frequency and severity, which was not better accounted for by the amount of sleep. These findings support the plausibility and need for further investigation of a circadian pathway in the development and maintenance of chronic headaches. Specifically, circadian misalignment and delayed sleep timing could serve as an exacerbating factor in chronic migraines when combined with biological predispositions or environmental factors. © 2018 American Headache Society.

The endogenous circadian temperature period length (tau) in delayed sleep phase disorder compared to good sleepers.

PubMed

Micic, Gorica; de Bruyn, Amanda; Lovato, Nicole; Wright, Helen; Gradisar, Michael; Ferguson, Sally; Burgess, Helen J; Lack, Leon

2013-12-01

The currently assumed aetiology for delayed sleep phase disorder (DSPD) is a delay of the circadian system. Clinicians have sought to use bright light therapy, exogenous melatonin or chronotherapy to correct the disorder. However, these treatments have achieved unreliable outcomes for DSPD patients and, as such, one suggestion has been that the disorder may be caused by a longer than normal circadian rhythm period length (i.e. tau). The present study investigated this premise using a 78-h ultradian, ultra-short sleep-wake cycle. This constant bedrest routine was used to simulate a series of 1-h long 'days' by alternating 20-min sleep opportunities and 40 min of enforced wakefulness. Thirteen participants were recruited for the study including, six people diagnosed with DSPD according to the International Classification of Sleep Disorders-2 [mean age = 22.0, standard deviation (SD) = 3.3] and seven good sleepers (mean age = 23.1, SD = 3.9) with normal sleep timing. The DSPD participants' core temperature rhythm tau (mean = 24 h 54 min, SD = 23 min) was significantly longer (t = -2.33, P = 0.04, Cohen's d = 1.91) than the good sleepers' (mean 24 h 29 min, SD = 16 min). The temperature rhythm of the DSPD participants delayed more rapidly (i.e. >25 min day(-1) ) than the good sleepers'. These findings provide an explanation for the difficulty that DSPD patients have in phase advancing to a more conventional sleep time and their frequent relapse following treatment. The outcomes of this study support a vigorous and continued application of chronobiological and behavioural therapies to entrain DSPD patients to their desired earlier sleep times. © 2013 European Sleep Research Society.

Circadian Rhythm Sleep-Wake Disorders.

PubMed

Pavlova, Milena

2017-08-01

The endogenous circadian rhythms are one of the cardinal processes that control sleep. They are self-sustaining biological rhythms with a periodicity of approximately 24 hours that may be entrained by external zeitgebers (German for time givers), such as light, exercise, and meal times. This article discusses the physiology of the circadian rhythms, their relationship to neurologic disease, and the presentation and treatment of circadian rhythm sleep-wake disorders. Classic examples of circadian rhythms include cortisol and melatonin secretion, body temperature, and urine volume. More recently, the impact of circadian rhythm on several neurologic disorders has been investigated, such as the timing of occurrence of epileptic seizures as well as neurobehavioral functioning in dementia. Further updates include a more in-depth understanding of the symptoms, consequences, and treatment of circadian sleep-wake disorders, which may occur because of extrinsic misalignment with clock time or because of intrinsic dysfunction of the brain. An example of extrinsic misalignment occurs with jet lag during transmeridian travel or with intrinsic circadian rhythm sleep-wake disorders such as advanced or delayed sleep-wake phase disorders. In advanced sleep-wake phase disorder, which is most common in elderly individuals, sleep onset and morning arousal are undesirably early, leading to impaired evening function with excessive sleepiness and sleep-maintenance insomnia with early morning awakening. By contrast, delayed sleep-wake phase disorder is characterized by an inability to initiate sleep before the early morning hours, with subsequent delayed rise time, leading to clinical symptoms of severe sleep-onset insomnia coupled with excessive daytime sleepiness in the morning hours, as patients are unable to "sleep in" to attain sufficient sleep quantity. Irregular sleep-wake rhythm disorder is misentrainment with patches of brief sleep and wakefulness spread throughout the day, leading to unstable sleep and waking behavioral patterns and an entirely idiosyncratic sleep-wake schedule. Familiarity with these major circadian rhythm sleep-wake disorder phenotypes and their overlap with other neurologic disorders is essential for the neurologist so that clinicians may intervene and improve patient functioning and quality of life.

A single dose of alcohol does not meaningfully alter circadian phase advances and phase delays to light in humans

PubMed Central

Rizvydeen, Muneer; Fogg, Louis F.; Keshavarzian, Ali

2016-01-01

Central circadian timing influences mental and physical health. Research in nocturnal rodents has demonstrated that when alcohol is consumed, it reaches the central hypothalamic circadian pacemaker (suprachiasmatic nuclei) and can directly alter circadian phase shifts to light. In two separate studies, we examined, for the first time, the effects of a single dose of alcohol on circadian phase advances and phase delays to light in humans. Two 23-day within-subjects placebo-controlled counterbalanced design studies were conducted. Both studies consisted of 6 days of fixed baseline sleep to stabilize circadian timing, a 2-day laboratory session, a 6-day break, and a repeat of 6 days of fixed sleep and a 2-day laboratory session. In the phase advance study (n = 10 light drinkers, 24–45 yr), the laboratory sessions consisted of a baseline dim light phase assessment, sleep episode, alcohol (0.6 g/kg) or placebo, 2-h morning bright light pulse, and final phase assessment. In the phase-delay study (n = 14 light drinkers, 22–44 yr), the laboratory sessions consisted of a baseline phase assessment, alcohol (0.8 g/kg) or placebo, 2-h late night bright light pulse, sleep episode, and final phase assessment. In both studies, alcohol either increased or decreased the observed phase shifts to light (interaction P ≥ 0.46), but the effect of alcohol vs. placebo on phase shifts to light was always on average smaller than 30 min. Thus, no meaningful effects of a single dose of alcohol vs. placebo on circadian phase shifts to light in humans were observed. PMID:26936778

A single dose of alcohol does not meaningfully alter circadian phase advances and phase delays to light in humans.

PubMed

Burgess, Helen J; Rizvydeen, Muneer; Fogg, Louis F; Keshavarzian, Ali

2016-04-15

Central circadian timing influences mental and physical health. Research in nocturnal rodents has demonstrated that when alcohol is consumed, it reaches the central hypothalamic circadian pacemaker (suprachiasmatic nuclei) and can directly alter circadian phase shifts to light. In two separate studies, we examined, for the first time, the effects of a single dose of alcohol on circadian phase advances and phase delays to light in humans. Two 23-day within-subjects placebo-controlled counterbalanced design studies were conducted. Both studies consisted of 6 days of fixed baseline sleep to stabilize circadian timing, a 2-day laboratory session, a 6-day break, and a repeat of 6 days of fixed sleep and a 2-day laboratory session. In the phase advance study (n= 10 light drinkers, 24-45 yr), the laboratory sessions consisted of a baseline dim light phase assessment, sleep episode, alcohol (0.6 g/kg) or placebo, 2-h morning bright light pulse, and final phase assessment. In the phase-delay study (n= 14 light drinkers, 22-44 yr), the laboratory sessions consisted of a baseline phase assessment, alcohol (0.8 g/kg) or placebo, 2-h late night bright light pulse, sleep episode, and final phase assessment. In both studies, alcohol either increased or decreased the observed phase shifts to light (interaction P≥ 0.46), but the effect of alcohol vs. placebo on phase shifts to light was always on average smaller than 30 min. Thus, no meaningful effects of a single dose of alcohol vs. placebo on circadian phase shifts to light in humans were observed. Copyright © 2016 the American Physiological Society.

Sleep and cognitive performance of African-Americans and European-Americans before and during circadian misalignment produced by an abrupt 9-h delay in the sleep/wake schedule

PubMed Central

Crowley, Stephanie J.; Eastman, Charmane I.

2017-01-01

We conducted two studies of circadian misalignment in non-Hispanic African and European-Americans. In the first, the sleep/wake (light/dark) schedule was advanced 9 h, similar to flying east, and in the second these schedules were delayed 9 h, similar to flying west or sleeping during the day after night work. We confirmed that the free-running circadian period is shorter in African-Americans compared to European-Americans, and found differences in the magnitude and direction of circadian rhythm phase shifts which were related to the circadian period. The sleep and cognitive performance data from the first study (published in this journal) documented the impairment in both ancestry groups due to this extreme circadian misalignment. African-Americans slept less and performed slightly worse during advanced/misaligned days than European-Americans. The current analysis is of sleep and cognitive performance from the second study. Participants were 23 African-Americans and 22 European-Americans (aged 18–44 years). Following four baseline days (8 h time in bed, based on habitual sleep), the sleep/wake schedule was delayed by 9 h for three days. Sleep was monitored using actigraphy. During the last two baseline/aligned days and the first two delayed/misaligned days, beginning 2 h after waking, cognitive performance was assessed every 3 h using the Automated Neuropsychological Assessment Metrics (ANAM) battery. Mixed model ANOVAs assessed the effects of ancestry (African-American or European-American) and condition (baseline/aligned or delayed/misaligned) on sleep and performance. There was decreased sleep and impaired cognitive performance in both ancestry groups during the two delayed/misaligned days relative to baseline/aligned days. Sleep and cognitive performance did not differ between African-Americans and European-Americans during either baseline/aligned or delayed/misaligned days. While our previous work showed that an advance in the sleep/wake schedule impaired the sleep of African-Americans more than European-Americans, delaying the sleep/wake schedule impaired the sleep and cognitive performance of African-Americans and European-Americans equally. PMID:29073187

Diagnostic and Treatment Challenges of Sighted Non-24-Hour Sleep-Wake Disorder.

PubMed

Malkani, Roneil G; Abbott, Sabra M; Reid, Kathryn J; Zee, Phyllis C

2018-04-15

To report the diagnostic and treatment challenges of sighted non-24-hour sleep-wake disorder (N24SWD). We report a series of seven sighted patients with N24SWD clinically evaluated by history and sleep diaries, and when available wrist actigraphy and salivary melatonin levels, and treated with timed melatonin and bright light therapy. Most patients had a history of a delayed sleep-wake pattern prior to developing N24SWD. The typical sleep-wake pattern of N24SWD was seen in the sleep diaries (and in actigraphy when available) in all patients with a daily delay in midpoint of sleep ranging 0.8 to 1.8 hours. Salivary dim light melatonin onset (DLMO) was evaluated in four patients but was missed in one. The estimated phase angle from DLMO to sleep onset ranged from 5.25 to 9 hours. All six patients who attempted timed melatonin and bright light therapy were able to entrain their sleep-wake schedules. Entrainment occurred at a late circadian phase, possibly related to the late timing of melatonin administration, though the patients often preferred late sleep times. Most did not continue treatment and continued to have a non-24-hour sleep-wake pattern. N24SWD is a chronic debilitating disorder that is often overlooked in sighted people and can be challenging to diagnose and treat. Tools to assess circadian pattern and timing can be effectively applied to aid the diagnosis. The progressive delay of the circadian rhythm poses a challenge for determining the most effective timing for melatonin and bright light therapies. Furthermore, once the circadian sleep-wake rhythm is entrained, long-term effectiveness is limited because of the behavioral and environmental structure that is required to maintain stable entrainment. © 2018 American Academy of Sleep Medicine.

Integration of human sleep-wake regulation and circadian rhythmicity

NASA Technical Reports Server (NTRS)

Dijk, Derk-Jan; Lockley, Steven W.

2002-01-01

The human sleep-wake cycle is generated by a circadian process, originating from the suprachiasmatic nuclei, in interaction with a separate oscillatory process: the sleep homeostat. The sleep-wake cycle is normally timed to occur at a specific phase relative to the external cycle of light-dark exposure. It is also timed at a specific phase relative to internal circadian rhythms, such as the pineal melatonin rhythm, the circadian sleep-wake propensity rhythm, and the rhythm of responsiveness of the circadian pacemaker to light. Variations in these internal and external phase relationships, such as those that occur in blindness, aging, morning and evening, and advanced and delayed sleep-phase syndrome, lead to sleep disruptions and complaints. Changes in ocular circadian photoreception, interindividual variation in the near-24-h intrinsic period of the circadian pacemaker, and sleep homeostasis can contribute to variations in external and internal phase. Recent findings on the physiological and molecular-genetic correlates of circadian sleep disorders suggest that the timing of the sleep-wake cycle and circadian rhythms is closely integrated but is, in part, regulated differentially.

A randomized controlled trial with bright light and melatonin for delayed sleep phase disorder: effects on subjective and objective sleep.

PubMed

Saxvig, Ingvild West; Wilhelmsen-Langeland, Ane; Pallesen, Ståle; Vedaa, Oystein; Nordhus, Inger Hilde; Bjorvatn, Bjørn

2014-02-01

Delayed sleep phase disorder (DSPD) is assumed to be common amongst adolescents, with potentially severe consequences in terms of school attendance and daytime functioning. The most common treatment approaches for DSPD are based on the administration of bright light and/or exogenous melatonin with or without adjunct behavioural instructions. Much is generally known about the chronobiological effects of light and melatonin. However, placebo-controlled treatment studies for DSPD are scarce, in particular in adolescents and young adults, and no standardized guidelines exist regarding treatment. The aim of the present study was, therefore, to investigate the short- and long-term effects on sleep of a DSPD treatment protocol involving administration of timed bright light and melatonin alongside gradual advancement of rise time in adolescents and young adults with DSPD in a randomized controlled trial and an open label follow-up study. A total of 40 adolescents and young adults (age range 16-25 years) diagnosed with DSPD were recruited to participate in the study. The participants were randomized to receive treatment for two weeks in one of four treatment conditions: dim light and placebo capsules, bright light and placebo capsules, dim light and melatonin capsules or bright light and melatonin capsules. In a follow-up study, participants were re-randomized to either receive treatment with the combination of bright light and melatonin or no treatment in an open label trial for approximately three months. Light and capsules were administered alongside gradual advancement of rise times. The main end points were sleep as assessed by sleep diaries and actigraphy recordings and circadian phase as assessed by salivary dim light melatonin onset (DLMO). During the two-week intervention, the timing of sleep and DLMO was advanced in all treatment conditions as seen by about 1 h advance of bed time, 2 h advance of rise time and 2 h advance of DLMO in all four groups. Sleep duration was reduced with approximately 1 h. At three-month follow-up, only the treatment group had maintained an advanced sleep phase. Sleep duration had returned to baseline levels in both groups. In conclusion, gradual advancement of rise time produced a phase advance during the two-week intervention, irrespective of treatment condition. Termination of treatment caused relapse into delayed sleep times, whereas long-term treatment with bright light and melatonin (three months) allowed maintenance of the advanced sleep phase.

Effects on subjective and objective alertness and sleep in response to evening light exposure in older subjects

PubMed Central

Münch, M; Scheuermaier, KD; Zhang, R; Dunne, SP; Guzik, AM; Silva, EJ; Ronda, JM; Duffy, JF

2011-01-01

Evening bright light exposure is reported to ameliorate daytime sleepiness and age-related sleep complaints, and also delays the timing of circadian rhythms. We tested whether evening light exposure given to older adults with sleep-wake complaints would delay the timing of their circadian rhythms with respect to their sleep timing, thereby reducing evening sleepiness and improving subsequent sleep quality. We examined the impact of evening light exposure from two different light sources on subjective alertness, EEG activity during wakefulness, and sleep stages. Ten healthy older adults with sleep complaints (mean age=63.3 yrs; 6F) participated in a 13-day study. After three baseline days, circadian phase was assessed. On the evening of days 5–8 the subjects were exposed for 2 h to either polychromatic blue-enriched white light or standard white fluorescent light, and on the following day circadian phase was re-assessed. Subjects were allowed to leave the laboratory during all but the two days when the circadian phase assessment took place. Evening assessments of subjective alertness, and wake and sleep EEG data were analyzed. Subjective alertness and wake EEG activity in the alpha range (9.75–11.25 Hz) were significantly higher during light exposures when compared to the pre-light exposure evening (p<0.05). The light exposures produced circadian phase shifts and significantly prolonged latency to rapid eye-movement (REM) sleep for both light groups (p<0.05). The increase in wake EEG alpha activity during the light exposures was negatively correlated with REM sleep duration (p<0.05). Evening light exposure could benefit older adults with early evening sleepiness, without negatively impacting the subsequent sleep episode. PMID:21664380

Changing Adolescent Sleep Patterns: Factors Affecting them and the Related Problems.

PubMed

Kaur, Harpreet; Bhoday, Harpreet Singh

2017-03-01

Sleep affects physical growth, behavior and emotional development besides determining cognitive functioning, learning and attention especially of a growing child. Adolescence represents one of the critical transitions in the life span and is characterized by a tremendous pace in growth and change that is second only to that of infancy. Adolescent sleep patterns deserve particular attention because of the potential impact on school performance. Average sleep period in adolescents is reduced during school days to around seven hours. The reasons may be biological mainly the sleep phase delay or psychosocial and environmental. These include academic demands, social activities, sports, internet, television viewing, part-time employment, and use of mobile phone at night, peer and parental influence and socioeconomic status. These changing patterns of sleep in adolescents lead to many behavioral sleep problems like Delayed Sleep-phase Syndrome; Difficulties in falling asleep (insomnia); excessive daytime sleepiness, poor academic performance. Decreased sleep in adolescents also causes obesity and other cardio-metabolic abnormalities. This needs an integrated approach involving adolescents themselves, their parents, teachers and specialized physicians to help improve the sleep quantity and quality and lead to a better quality of life and daytime functioning in adolescents. © Journal of the Association of Physicians of India 2011.

Sleep and circadian variability in people with delayed sleep-wake phase disorder versus healthy controls.

PubMed

Burgess, Helen J; Park, Margaret; Wyatt, James K; Rizvydeen, Muneer; Fogg, Louis F

2017-06-01

To compare sleep and circadian variability in adults with delayed sleep-wake phase disorder (DSWPD) to healthy controls. Forty participants (22 DSWPD, 18 healthy controls) completed a ten-day protocol, consisting of DLMO assessments on two consecutive nights, a five-day study break, followed by two more DLMO assessments. All participants were instructed to sleep within one hour of their self-reported average sleep schedule for the last four days of the study break. We analyzed the participants' wrist actigraphy data during these four days to examine intraindividual variability in sleep timing, duration and efficiency. We also examined shifts in the DLMO from before and after the study break. Under the same conditions, people with DSWPD had significantly more variable wake times and total sleep time than healthy controls (p ≤ 0.015). Intraindividual variability in sleep onset time and sleep efficiency was similar between the two groups (p ≥ 0.30). The DLMO was relatively stable across the study break, with only 11% of controls but 27% of DSWPDs showed more than a one hour shift in the DLMO. Only in the DSWPD sample was greater sleep variability associated with a larger shift in the DLMO (r = 0.46, p = 0.03). These results suggest that intraindividual variability in sleep can be higher in DSWPD versus healthy controls, and this may impact variability in the DLMO. DSWPD patients with higher intraindividual variability in sleep are more likely to have a shifting DLMO, which could impact sleep symptoms and the optimal timing of light and/or melatonin treatment for DSWPD. Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. Copyright © 2017 Elsevier B.V. All rights reserved.

Sleep Deprivation and Caffeine Treatment Potentiate Photic Resetting of the Master Circadian Clock in a Diurnal Rodent.

PubMed

Jha, Pawan Kumar; Bouâouda, Hanan; Gourmelen, Sylviane; Dumont, Stephanie; Fuchs, Fanny; Goumon, Yannick; Bourgin, Patrice; Kalsbeek, Andries; Challet, Etienne

2017-04-19

Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light/dark cycle. However, nonphotic factors, such as behavioral arousal and metabolic cues, can also phase shift the master clock in the suprachiasmatic nuclei (SCNs) and/or reduce the synchronizing effects of light in nocturnal rodents. In diurnal rodents, the role of arousal or insufficient sleep in these functions is still poorly understood. In the present study, diurnal Sudanian grass rats, Arvicanthis ansorgei , were aroused at night by sleep deprivation (gentle handling) or caffeine treatment that both prevented sleep. Phase shifts of locomotor activity were analyzed in grass rats transferred from a light/dark cycle to constant darkness and aroused in early night or late night. Early night, but not late night, sleep deprivation induced a significant phase shift. Caffeine on its own induced no phase shifts. Both sleep deprivation and caffeine treatment potentiated light-induced phase delays and phase advances in response to a 30 min light pulse, respectively. Sleep deprivation in early night, but not late night, potentiated light-induced c-Fos expression in the ventral SCN. Caffeine treatment in midnight triggered c-Fos expression in dorsal SCN. Both sleep deprivation and caffeine treatment potentiated light-induced c-Fos expression in calbindin-containing cells of the ventral SCN in early and late night. These findings indicate that, in contrast to nocturnal rodents, behavioral arousal induced either by sleep deprivation or caffeine during the sleeping period potentiates light resetting of the master circadian clock in diurnal rodents, and activation of calbindin-containing suprachiasmatic cells may be involved in this effect. SIGNIFICANCE STATEMENT Arousing stimuli have the ability to regulate circadian rhythms in mammals. Behavioral arousal in the sleeping period phase shifts the master clock in the suprachiasmatic nuclei and/or slows down the photic entrainment in nocturnal animals. How these stimuli act in diurnal species remains to be established. Our study in a diurnal rodent, the Grass rat, indicates that sleep deprivation in the early rest period induces phase delays of circadian locomotor activity rhythm. Contrary to nocturnal rodents, both sleep deprivation and caffeine-induced arousal potentiate the photic entrainment in a diurnal rodent. Such enhanced light-induced circadian responses could be relevant for developing chronotherapeutic strategies. Copyright © 2017 the authors 0270-6474/17/374343-16$15.00/0.

Pulsing blue light through closed eyelids: effects on acute melatonin suppression and phase shifting of dim light melatonin onset.

PubMed

Figueiro, Mariana G; Plitnick, Barbara; Rea, Mark S

2014-01-01

Circadian rhythm disturbances parallel the increased prevalence of sleep disorders in older adults. Light therapies that specifically target regulation of the circadian system in principle could be used to treat sleep disorders in this population. Current recommendations for light treatment require the patients to sit in front of a bright light box for at least 1 hour daily, perhaps limiting their willingness to comply. Light applied through closed eyelids during sleep might not only be efficacious for changing circadian phase but also lead to better compliance because patients would receive light treatment while sleeping. Reported here are the results of two studies investigating the impact of a train of 480 nm (blue) light pulses presented to the retina through closed eyelids on melatonin suppression (laboratory study) and on delaying circadian phase (field study). Both studies employed a sleep mask that provided narrowband blue light pulses of 2-second duration every 30 seconds from arrays of light-emitting diodes. The results of the laboratory study demonstrated that the blue light pulses significantly suppressed melatonin by an amount similar to that previously shown in the same protocol at half the frequency (ie, one 2-second pulse every minute for 1 hour). The results of the field study demonstrated that blue light pulses given early in the sleep episode significantly delayed circadian phase in older adults; these results are the first to demonstrate the efficacy and practicality of light treatment by a sleep mask aimed at adjusting circadian phase in a home setting.

Melatonin and Melatonin Agonists as Adjunctive Treatments in Bipolar Disorders.

PubMed

Geoffroy, Pierre Alexis; Etain, Bruno; Franchi, Jean-Arthur Micoulaud; Bellivier, Frank; Ritter, Philipp

2015-01-01

Bipolar disorders (BD) present with abnormalities of circadian rhythmicity and sleep homeostasis, even during phases of remission. These abnormalities are linked to the underlying neurobiology of genetic susceptibility to BD. Melatonin is a pineal gland secreted neurohormone that induces circadian-related and sleep-related responses. Exogenous melatonin has demonstrated efficacy in treating primary insomnia, delayed sleep phase disorder, improving sleep parameters and overall sleep quality, and some psychiatric disorders like autistic spectrum disorders. In order to evaluate the efficacy of melatonin among patients with BD, this comprehensive review emphasizes the abnormal melatonin function in BD, the rationale of melatonin action in BD, the available data about the exogenous administration of melatonin, and melatonin agonists (ramelteon and tasimelteon), and recommendations of use in patients with BD. There is a scientific rationale to propose melatonin-agonists as an adjunctive treatment of mood stabilizers in treating sleep disorders in BD and thus to possibly prevent relapses when administered during remission phases. We emphasized the need to treat insomnia, sleep delayed latencies and sleep abnormalities in BD that are prodromal markers of an emerging mood episode and possible targets to prevent future relapses. An additional interesting adjunctive therapeutic effect might be on preventing metabolic syndrome, particularly in patients treated with antipsychotics. Finally, melatonin is well tolerated and has little dependence potential in contrast to most available sleep medications. Further studies are expected to be able to produce stronger evidence-based therapeutic guidelines to confirm and delineate the routine use of melatonin-agonists in the treatment of BD.

Are cognitive "insomnia" processes involved in the development and maintenance of delayed sleep wake phase disorder?

PubMed

Richardson, Cele E; Gradisar, Michael; Barbero, Sebastian C

2016-04-01

Although individuals with delayed sleep wake phase disorder (DSWPD) and chronic insomnia disorder (CID) share many of the same phenomenological experiences, theories relating to the development and maintenance of these disorders are distinct in focus. Unlike CID, theory relating to DSWPD is primarily physiologically based and assumes almost no cognitive pathway. However, recent research findings suggest that individuals with DSWPD also display many of the sleep-disordered cognitive processes that were previously assumed to be unique to the insomnia experience. As such, this review aims to summarise current research findings to address the question "Could cognitive processes be involved in the development and maintenance of DSWPD?" In particular, the presence of cognitive and physiological pre-sleep arousal, sleep-related attentional bias, distorted perception of sleep and daytime functioning, dysfunctional beliefs and safety behaviours will be investigated. As this emerging area of research requires a stronger evidence base, we highlight suggestions for future investigation and provide preliminary practice points for clinicians assessing and treating "insomnia" in patients with DSWPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

The 3111 Clock gene polymorphism is not associated with sleep and circadian rhythmicity in phenotypically characterized human subjects.

PubMed

Robilliard, Donna L; Archer, Simon N; Arendt, Josephine; Lockley, Steven W; Hack, Lisa M; English, Judie; Leger, Damien; Smits, Marcel G; Williams, Adrian; Skene, Debra J; Von Schantz, Malcolm

2002-12-01

Mutations in clock genes are associated with abnormal circadian parameters, including sleep. An association has been reported previously between a polymorphism (3111C), situated in the 3'-untranslated region (3'-UTR) of the circadian gene Clock and evening preference. In the present study, this polymorphism was assessed in: (1) 105 control subjects with defined diurnal preference, (2) 26 blind subjects with free-running circadian rhythms and characterized with regard to circadian period (tau) and (3) 16 delayed sleep phase syndrome patients. The control group was chosen from a larger population (n = 484) by Horne-Ostberg questionnaire analysis, from which three subgroups were selected (evening, intermediate and morning preference). Data from sleep diaries completed by 90% of these subjects showed a strong correlation between preferred and estimated timings of sleep and wake. The mean timings of activities for the evening group were at least 2 h later than the morning group. Genetic analysis showed that, in contrast with the previously published finding, there was no association between 3111C and eveningness. Neither was there an association between 3111C and tau, nor a significant difference in 3111C frequency between the normal and delayed sleep phase syndrome groups. To assess the effect of this polymorphism on messenger RNA (mRNA) translatability, luciferase reporter gene constructs containing the two Clock polymorphic variants in their 3'-UTR were transfected into COS-1 cells and luciferase activity measured. No significant difference was observed between the two variants. These results do not support Clock 3111C as a marker for diurnal preference, tau, or delayed sleep phase syndrome in humans.

Does the transition into daylight saving time really cause partial sleep deprivation?

PubMed

Toth Quintilham, Manoel Carlos; Adamowicz, Taísa; Pereira, Erico Felden; Pedrazzoli, Mario; Louzada, Fernando Mazzilli

2014-01-01

To identify possible changes in the sleep patterns according to chronotype in undergraduate students during the daylight saving time (DST) transition. A total of 378 students answered the Morningness-Eveningness Questionnaire (MEQ) to determine their chronotype and kept a diary about sleep-wake schedules 1 week before and after the DST transition. Oral mucosal cell samples were collected for genetic analysis. After the DST transition, intermediate types (I-types) delayed bedtime and increased their time in bed and all groups delayed their wake-up time. All groups presented a shorter phase angle between sunset and the bedtime after the DST transition. On the other hand, only E-types showed a tendency to reduce the phase angle between sunrise and wake-up time, while I-types and M-types kept the same phase angles between sunrise and wake-up time after the DST transition. The polymorphisms in the human genes CLOCK and PER3 were not associated with individual differences in sleep patterns, nor were they associated with an adjustment to the DST transition. Under the new set of social times determined by DST, the adjustment was only partial. I-types delayed bedtime and all groups delayed their wake-up times after the beginning of DST. Consequently, the time in bed after the DST transition was not reduced; Morning (M-types) and Evening-types (E-types) kept the same time in bed and I-types showed an increase on it.

A Randomized Controlled Trial of Cognitive-Behavior Therapy Plus Bright Light Therapy for Adolescent Delayed Sleep Phase Disorder

PubMed Central

Gradisar, Michael; Dohnt, Hayley; Gardner, Greg; Paine, Sarah; Starkey, Karina; Menne, Annemarie; Slater, Amy; Wright, Helen; Hudson, Jennifer L.; Weaver, Edward; Trenowden, Sophie

2011-01-01

Objective: To evaluate cognitive-behavior therapy plus bright light therapy (CBT plus BLT) for adolescents diagnosed with delayed sleep phase disorder (DSPD). Design: Randomized controlled trial of CBT plus BLT vs. waitlist (WL) control with comparisons at pre- and post-treatment. There was 6-month follow-up for the CBT plus BLT group only. Setting: Flinders University Child & Adolescent Sleep Clinic, Adelaide, South Australia. Patients: 49 adolescents (mean age 14.6 ± 1.0 y, 53% males) diagnosed with DSPD; mean chronicity 4 y 8 months; 16% not attending school. Eighteen percent of adolescents dropped out of the study (CBT plus BLT: N = 23 vs WL: N = 17). Interventions: CBT plus BLT consisted of 6 individual sessions, including morning bright light therapy to advance adolescents' circadian rhythms, and cognitive restructuring and sleep education to target associated insomnia and sleep hygiene. Measurements and Results: DSPD diagnosis was performed via a clinical interview and 7-day sleep diary. Measurements at each time-point included online sleep diaries and scales measuring sleepiness, fatigue, and depression symptoms. Compared to WL, moderate-to-large improvements (d = 0.65-1.24) were found at post-treatment for CBT plus BLT adolescents, including reduced sleep latency, earlier sleep onset and rise times, total sleep time (school nights), wake after sleep onset, sleepiness, and fatigue. At 6-month follow-up (N = 15), small-to-large improvements (d = 0.24-1.53) continued for CBT plus BLT adolescents, with effects found for all measures. Significantly fewer adolescents receiving CBT plus BLT met DPSD criteria at post-treatment (WL = 82% vs. CBT plus BLT = 13%, P < 0.0001), yet 13% still met DSPD criteria at the 6-month follow-up. Conclusions: CBT plus BLT for adolescent DSPD is effective for improving multiple sleep and daytime impairments in the immediate and long-term. Studies evaluating the treatment effectiveness of each treatment component are needed. Clinical Trial Information: Australia – New Zealand Trials Registry Number: ACTRN12610001041044. Citation: Gradisar M; Dohnt H; Gardner G; Paine S; Starkey K; Menne A; Slater A; Wright H; Hudson JL; Weaver E; Trenowden S. A randomized controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent delayed sleep phase disorder. SLEEP 2011;34(12):1671-1680. PMID:22131604

[How to characterize and treat sleep complaints in bipolar disorders?

PubMed

Geoffroy, P A; Micoulaud Franchi, J-A; Lopez, R; Poirot, I; Brion, A; Royant-Parola, S; Etain, B

2017-08-01

Sleep complaints are very common in bipolar disorders (BD) both during acute phases (manic and depressive episodes) and remission (about 80 % of patients with remitted BD have poor sleep quality). Sleep complaints during remission are of particular importance since they are associated with more mood relapses and worse outcomes. In this context, this review discusses the characterization and treatment of sleep complaints in BD. We examined the international scientific literature in June 2016 and performed a literature search with PubMed electronic database using the following headings: "bipolar disorder" and ("sleep" or "insomnia" or "hypersomnia" or "circadian" or "apnoea" or "apnea" or "restless legs"). Patients with BD suffer from sleep and circadian rhythm abnormalities during major depressive episodes (insomnia or hypersomnia, nightmares, nocturnal and/or early awakenings, non-restorative sleep) and manic episodes (insomnia, decreased need for sleep without fatigue), but also some of these abnormalities may persist during remission. These remission phases are characterized by a reduced quality and quantity of sleep, with a longer sleep duration, increased sleep latency, a lengthening of the wake time after sleep onset (WASO), a decrease of sleep efficiency, and greater variability in sleep/wake rhythms. Patients also present frequent sleep comorbidities: chronic insomnia, sleepiness, sleep phase delay syndrome, obstructive sleep apnea/hypopnea syndrome (OSAHS), and restless legs syndrome (RLS). These disorders are insufficiently diagnosed and treated whereas they are associated with mood relapses, treatment resistance, affect cognitive global functioning, reduce the quality of life, and contribute to weight gain or metabolic syndrome. Sleep and circadian rhythm abnormalities have been also associated with suicidal behaviors. Therefore, a clinical exploration with characterization of these abnormalities and disorders is essential. This exploration should be helped by questionnaires and documented on sleep diaries or even actimetric objective measures. Explorations such as ventilatory polygraphy, polysomnography or a more comprehensive assessment in a sleep laboratory may be required to complete the diagnostic assessment. Treatments obviously depend on the cause identified through assessment procedures. Treatment of chronic insomnia is primarily based on non-drug techniques (by restructuring behavior and sleep patterns), on psychotherapy (cognitive behavioral therapy for insomnia [CBT-I]; relaxation; interpersonal and social rhythm therapy [IPSRT]; etc.), and if necessary with hypnotics during less than four weeks. Specific treatments are needed in phase delay syndrome, OSAHS, or other more rare sleep disorders. BD are defined by several sleep and circadian rhythm abnormalities during all phases of the disorder. These abnormalities and disorders, especially during remitted phases, should be characterized and diagnosed to reduce mood relapses, treatment resistance and improve BD outcomes. Copyright © 2016 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Human Adolescent Phase Response Curves to Bright White Light.

PubMed

Crowley, Stephanie J; Eastman, Charmane I

2017-08-01

Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

Sleep-wake profiles and circadian rhythms of core temperature and melatonin in young people with affective disorders.

PubMed

Carpenter, Joanne S; Robillard, Rébecca; Hermens, Daniel F; Naismith, Sharon L; Gordon, Christopher; Scott, Elizabeth M; Hickie, Ian B

2017-11-01

While disturbances of the sleep-wake cycle are common in people with affective disorders, the characteristics of these disturbances differ greatly between individuals. This heterogeneity is likely to reflect multiple underlying pathophysiologies, with different perturbations in circadian systems contributing to the variation in sleep-wake cycle disturbances. Such disturbances may be particularly relevant in adolescents and young adults with affective disorders as circadian rhythms undergo considerable change during this key developmental period. This study aimed to identify profiles of sleep-wake disturbance in young people with affective disorders and investigate associations with biological circadian rhythms. Fifty young people with affective disorders and 19 control participants (aged 16-31 years) underwent actigraphy monitoring for approximately two weeks to derive sleep-wake cycle parameters, and completed an in-laboratory assessment including evening dim-light saliva collection for melatonin assay and overnight continuous core body temperature measurement. Cluster analysis based on sleep-wake cycle parameters identified three distinct patient groups, characterised by 'delayed sleep-wake', 'disrupted sleep', and 'long sleep' respectively. The 'delayed sleep-wake' group had both delayed melatonin onset and core temperature nadir; whereas the other two cluster groups did not differ from controls on these circadian markers. The three groups did not differ on clinical characteristics. These results provide evidence that only some types of sleep-wake disturbance in young people with affective disorders are associated with fundamental circadian perturbations. Consequently, interventions targeting endogenous circadian rhythms to promote a phase shift may be particularly relevant in youth with affective disorders presenting with delayed sleep-wake cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness.

PubMed

Miller, Nita Lewis; Tvaryanas, Anthony P; Shattuck, Lawrence G

2012-08-01

This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. TRAINEES: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment.

Accommodating Adolescent Sleep-Wake Patterns: The Effects of Shifting the Timing of Sleep on Training Effectiveness

PubMed Central

Miller, Nita Lewis; Tvaryanas, Anthony P.; Shattuck, Lawrence G.

2012-01-01

Study Objective: This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. Design: The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. Setting: The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. Trainees: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. Measurements and Results: Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. Conclusions: Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment. Citation: Miller NL; Tvaryanas AP; Shattuck LG. Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness. SLEEP 2012;35(8):1123-1136. PMID:22851808

Home dim light melatonin onsets with measures of compliance in delayed sleep phase disorder.

PubMed

Burgess, Helen J; Park, Margaret; Wyatt, James K; Fogg, Louis F

2016-06-01

The dim light melatonin onset (DLMO) assists with the diagnosis and treatment of circadian rhythm sleep disorders. Home DLMOs are attractive for cost savings and convenience, but can be confounded by home lighting and sample timing errors. We developed a home saliva collection kit with objective measures of light exposure and sample timing. We report on our first test of the kit in a clinical population. Thirty-two participants with delayed sleep phase disorder (DSPD; 17 women, aged 18-52 years) participated in two back-to-back home and laboratory phase assessments. Most participants (66%) received at least one 30-s epoch of light >50 lux during the home phase assessments, but for only 1.5% of the time. Most participants (56%) collected every saliva sample within 5 min of the scheduled time. Eighty-three per cent of home DLMOs were not affected by light or sampling errors. The home DLMOs occurred, on average, 10.2 min before the laboratory DLMOs, and were correlated highly with the laboratory DLMOs (r = 0.93, P < 0.001). These results indicate that home saliva sampling with objective measures of light exposure and sample timing, can assist in identifying accurate home DLMOs. © 2016 European Sleep Research Society.

A Longitudinal Assessment of Sleep Timing, Circadian Phase, and Phase Angle of Entrainment across Human Adolescence

PubMed Central

Crowley, Stephanie J.; Van Reen, Eliza; LeBourgeois, Monique K.; Acebo, Christine; Tarokh, Leila; Seifer, Ronald; Barker, David H.; Carskadon, Mary A.

2014-01-01

The aim of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across adolescence in a longitudinal study design. Ninety-four adolescents participated; 38 (21 boys) were 9–10 years (“younger cohort”) and 56 (30 boys) were 15–16 years (“older cohort”) at the baseline assessment. Participants completed a baseline and then follow-up assessments approximately every six months for 2.5 years. At each assessment, participants wore a wrist actigraph for at least one week at home to measure self-selected sleep timing before salivary dim light melatonin onset (DLMO) phase – a marker of the circadian timing system – was measured in the laboratory. Weekday and weekend sleep onset and offset and weekend-weekday differences were derived from actigraphy. Phase angles were the time durations from DLMO to weekday sleep onset and offset times. Each cohort showed later sleep onset (weekend and weekday), later weekend sleep offset, and later DLMO with age. Weekday sleep offset shifted earlier with age in the younger cohort and later in the older cohort after age 17. Weekend-weekday sleep offset differences increased with age in the younger cohort and decreased in the older cohort after age 17. DLMO to sleep offset phase angle narrowed with age in the younger cohort and became broader in the older cohort. The older cohort had a wider sleep onset phase angle compared to the younger cohort; however, an age-related phase angle increase was seen in the younger cohort only. Individual differences were seen in these developmental trajectories. This descriptive study indicated that circadian phase and self-selected sleep delayed across adolescence, though school-day sleep offset advanced until no longer in high school, whereupon offset was later. Phase angle changes are described as an interaction of developmental changes in sleep regulation interacting with psychosocial factors (e.g., bedtime autonomy). PMID:25380248

The Timing of the Circadian Clock and Sleep Differ between Napping and Non-Napping Toddlers.

PubMed

Akacem, Lameese D; Simpkin, Charles T; Carskadon, Mary A; Wright, Kenneth P; Jenni, Oskar G; Achermann, Peter; LeBourgeois, Monique K

2015-01-01

The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers). Children followed their habitual napping and non-napping sleep schedules (monitored with actigraphy) for 5 days before an in-home salivary dim light melatonin onset (DLMO) assessment. On average, napping children fell asleep during their nap opportunities on 3.6±1.2 of the 5 days before the DLMO assessment. For these napping children, melatonin onset time was 38 min later (p = 0.044; d = 0.93), actigraphically-estimated bedtime was 43 min later (p = 0.014; d = 1.24), sleep onset time was 59 min later (p = 0.006; d = 1.46), and sleep onset latency was 16 min longer (p = 0.030; d = 1.03) than those not napping. Midsleep and wake time did not differ by napping status. No difference was observed in the bedtime, sleep onset, or midsleep phase relationships with DLMO; however, the wake time phase difference was 47 min smaller for napping toddlers (p = 0.029; d = 1.23). On average, nappers had 69 min shorter nighttime sleep durations (p = 0.006; d = 1.47) and spent 49 min less time in bed (p = 0.019; d = 1.16) than non-nappers. Number of days napping was correlated with melatonin onset time (r = 0.49; p = 0.014). Our findings indicate that napping influences individual variability in melatonin onset time in early childhood. The delayed bedtimes of napping toddlers likely permits light exposure later in the evening, thereby delaying the timing of the clock and sleep. Whether the early developmental trajectory of circadian phase involves an advance associated with the decline in napping is a question necessitating longitudinal data as children transition from a biphasic to monophasic sleep-wakefulness pattern.

The Timing of the Circadian Clock and Sleep Differ between Napping and Non-Napping Toddlers

PubMed Central

Akacem, Lameese D.; Simpkin, Charles T.; Carskadon, Mary A.; Wright, Kenneth P.; Jenni, Oskar G.; Achermann, Peter; LeBourgeois, Monique K.

2015-01-01

The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers). Children followed their habitual napping and non-napping sleep schedules (monitored with actigraphy) for 5 days before an in-home salivary dim light melatonin onset (DLMO) assessment. On average, napping children fell asleep during their nap opportunities on 3.6±1.2 of the 5 days before the DLMO assessment. For these napping children, melatonin onset time was 38 min later (p = 0.044; d = 0.93), actigraphically-estimated bedtime was 43 min later (p = 0.014; d = 1.24), sleep onset time was 59 min later (p = 0.006; d = 1.46), and sleep onset latency was 16 min longer (p = 0.030; d = 1.03) than those not napping. Midsleep and wake time did not differ by napping status. No difference was observed in the bedtime, sleep onset, or midsleep phase relationships with DLMO; however, the wake time phase difference was 47 min smaller for napping toddlers (p = 0.029; d = 1.23). On average, nappers had 69 min shorter nighttime sleep durations (p = 0.006; d = 1.47) and spent 49 min less time in bed (p = 0.019; d = 1.16) than non-nappers. Number of days napping was correlated with melatonin onset time (r = 0.49; p = 0.014). Our findings indicate that napping influences individual variability in melatonin onset time in early childhood. The delayed bedtimes of napping toddlers likely permits light exposure later in the evening, thereby delaying the timing of the clock and sleep. Whether the early developmental trajectory of circadian phase involves an advance associated with the decline in napping is a question necessitating longitudinal data as children transition from a biphasic to monophasic sleep-wakefulness pattern. PMID:25915066

PPARalpha is a potential therapeutic target of drugs to treat circadian rhythm sleep disorders.

PubMed

Shirai, Hidenori; Oishi, Katsutaka; Kudo, Takashi; Shibata, Shigenobu; Ishida, Norio

2007-06-08

Recent progress at the molecular level has revealed that nuclear receptors play an important role in the generation of mammalian circadian rhythms. To examine whether peroxisome proliferator-activated receptor alpha (PPARalpha) is involved in the regulation of circadian behavioral rhythms in mammals, we evaluated the locomotor activity of mice administered with the hypolipidemic PPARalpha ligand, bezafibrate. Circadian locomotor activity was phase-advanced about 3h in mice given bezafibrate under light-dark (LD) conditions. Transfer from LD to constant darkness did not change the onset of activity in these mice, suggesting that bezafibrate advanced the phase of the endogenous clock. Surprisingly, bezafibrate also advanced the phase in mice with lesions of the suprachiasmatic nucleus (SCN; the central clock in mammals). The circadian expression of clock genes such as period2, BMAL1, and Rev-erbalpha was also phase-advanced in various tissues (cortex, liver, and fat) without affecting the SCN. Bezafibrate also phase-advanced the activity phase that is delayed in model mice with delayed sleep phase syndrome (DSPS) due to a Clock gene mutation. Our results indicated that PPARalpha is involved in circadian clock control independently of the SCN and that PPARalpha could be a potent target of drugs to treat circadian rhythm sleep disorders including DSPS.

Sleep and Circadian Variability in People with Delayed Sleep-Wake Phase Disorder versus Healthy Controls

PubMed Central

Burgess, Helen J.; Park, Margaret; Wyatt, James K.; Rizvydeen, Muneer; Fogg, Louis F.

2017-01-01

Objective/Background To compare sleep and circadian variability in adults with delayed sleep-wake phase disorder (DSWPD) to healthy controls. Patients/Methods Forty participants (22 DSWPD, 18 healthy controls) completed a 10-day protocol, consisting of DLMO assessments on two consecutive nights, a five-day study break, followed by two more DLMO assessments. All participants were instructed to sleep within one hour of their self-reported average sleep schedule for the last four days of the study break. We analyzed the participants’ wrist actigraphy data during these four days to examine intraindividual variability in sleep timing, duration and efficiency. We also examined shifts in the DLMO from before and after the study break. Results and Conclusions Under the same conditions, people with DSWPD had significantly more variable wake times and total sleep time than healthy controls (p≤0.015). Intraindividual variability in sleep onset time and sleep efficiency was similar between the two groups (p≥0.30). The DLMO was relatively stable across the study break, with only 11% of controls but 27% of DSWPDs showed more than a one hour shift in the DLMO. Only in the DSWPD sample was greater sleep variability associated with a larger shift in the DLMO (r=0.46, p=0.03). These results suggest that intraindividual variability in sleep can be higher in DSWPD versus healthy controls, and this may impact variability in the DLMO. DSWPD patients with higher intraindividual variability in sleep are more likely to have a shifting DLMO, which could impact sleep symptoms and the optimal timing of light and/or melatonin treatment for DSWPD. PMID:28522096

Sleep in children with autism spectrum disorder.

PubMed

Kotagal, Suresh; Broomall, Eileen

2012-10-01

Children with autism spectrum disorder demonstrate an increased prevalence of difficulties with sleep initiation and maintenance. The consequences may include alterations in daytime behavior, memory, and learning in patients, and significant stress in caretakers. The dysregulation of melatonin synthesis, sensitization to environmental stimuli, behavioral insomnia syndromes, delayed sleep phase syndrome, rapid eye movement sleep behavior disorder, and comorbid anxiety, depression, and epilepsy comprise common etiologic factors. The clinical assessment of sleep problems in this population and a management algorithm are presented. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of an Advanced Sleep Schedule and Morning Short Wavelength Light Exposure on Circadian Phase in Young Adults with Late Sleep Schedules

PubMed Central

Sharkey, Katherine M.; Carskadon, Mary A.; Figueiro, Mariana G.; Zhu, Yong; Rea, Mark S.

2011-01-01

Objective We examined the effects of an advanced sleep/wake schedule and morning short wavelength (blue) light in 25 adults (mean age±SD = 21.8±3 years; 13 women) with late sleep schedules and subclinical features of delayed sleep phase syndrome (DSPD). Methods After a baseline week, participants kept individualized, fixed, advanced 7.5-hour sleep schedules for 6 days. Participants were randomly assigned to groups to receive “blue” (470 nm, ~225 lux, n=12) or “dim” (< 1 lux, n=13) light for one hour after waking each day. Head-worn “Daysimeters” measured light exposure; actigraphs and sleep diaries confirmed schedule compliance. Salivary dim light melatonin onset (DLMO), self-reported sleep, and mood were examined with 2×2 ANOVA. Results After 6 days, both groups showed significant circadian phase advances, but morning blue-light was not associated with larger phase shifts than dim-light exposure. The average DLMO advances (mean±SD) were 1.5±1.1 hours in the dim light group and 1.4±0.7 hours in the blue light group. Conclusions Adherence to a fixed advanced sleep/wake schedule resulted in significant circadian phase shifts in young adults with subclinical DSPD with or without morning blue light exposure. Light/dark exposures associated with fixed early sleep schedules are sufficient to advance circadian phase in young adults. PMID:21704557

Effects of an advanced sleep schedule and morning short wavelength light exposure on circadian phase in young adults with late sleep schedules.

PubMed

Sharkey, Katherine M; Carskadon, Mary A; Figueiro, Mariana G; Zhu, Yong; Rea, Mark S

2011-08-01

We examined the effects of an advanced sleep/wake schedule and morning short wavelength (blue) light in 25 adults (mean age±SD=21.8±3 years; 13 women) with late sleep schedules and subclinical features of delayed sleep phase disorder (DSPD). After a baseline week, participants kept individualized, fixed, advanced 7.5-h sleep schedules for 6days. Participants were randomly assigned to groups to receive "blue" (470nm, ∼225lux, n=12) or "dim" (<1lux, n=13) light for 1h after waking each day. Head-worn "Daysimeters" measured light exposure; actigraphs and sleep diaries confirmed schedule compliance. Salivary dim light melatonin onset (DLMO), self-reported sleep, and mood were examined with 2×2 ANOVA. After 6days, both groups showed significant circadian phase advances, but morning blue light was not associated with larger phase shifts than dim-light exposure. The average DLMO advances (mean±SD) were 1.5±1.1h in the dim light group and 1.4±0.7h in the blue light group. Adherence to a fixed advanced sleep/wake schedule resulted in significant circadian phase shifts in young adults with subclinical DSPD with or without morning blue light exposure. Light/dark exposures associated with fixed early sleep schedules are sufficient to advance circadian phase in young adults. Copyright © 2011 Elsevier B.V. All rights reserved.

A multicenter study of sleep-wake rhythm disorders: therapeutic effects of vitamin B12, bright light therapy, chronotherapy and hypnotics.

PubMed

Yamadera, H; Takahashi, K; Okawa, M

1996-08-01

One hundred and six subjects with primary sleep-wake rhythm disorders [13 non-24 hour sleep-wake syndrome (non-24), 76 delayed sleep phase syndrome (DSPS), 11 irregular sleep-wake pattern (irregular) and six long sleepers] were treated with vitamin B12, bright light, chronotherapy and/or hypnotics. These therapies caused moderate or remarkable improvement in 32% of the non-24, 42% of DSPS, 45% of irregular and 67% of long sleepers. A lack of adequate sleep, unpleasant feelings at waking and daytime drowsiness were also improved in DSPS.

Hypersomnia in children: interface with psychiatric disorders.

PubMed

Kotagal, Suresh

2009-10-01

Patients being evaluated in child psychiatry clinics for behavior and mood disturbances frequently exhibit daytime sleepiness. Conversely, patients being evaluated for hypersomnia by sleep specialists may have depressed mood or hyperactive and aggressive behavior. The etiology of daytime sleepiness in children and adolescents is diverse and includes inadequate sleep hygiene, obstructive sleep apnea, delayed sleep phase syndrome, idiopathic hypersomnia, periodic hypersomnia, narcolepsy, and mood disorders per se. Treatment of a sleep disorder can have a favorable impact on alertness and quality of life. A high index of suspicion for sleep problems should be maintained in children and adolescents with psychiatric disorders.

Individual Differences in Sleep Timing Relate to Melanopsin-Based Phototransduction in Healthy Adolescents and Young Adults.

PubMed

van der Meijden, Wisse P; Van Someren, Jamie L; Te Lindert, Bart H W; Bruijel, Jessica; van Oosterhout, Floor; Coppens, Joris E; Kalsbeek, Andries; Cajochen, Christian; Bourgin, Patrice; Van Someren, Eus J W

2016-06-01

Individual differences in sleep timing have been widely recognized and are of particular relevance in adolescents and young adults who often show mild to severely delayed sleep. The biological mechanisms underlying the between-subject variance remain to be determined. Recent human genetics studies showed an association between sleep timing and melanopsin gene variation, but support for functional effects on downstream pathways and behavior was not demonstrated before. We therefore investigated the association between the autonomic (i.e., pupil diameter) and behavioral (i.e., sleep timing) readouts of two different downstream brain areas, both affected by the same melanopsin-dependent retinal phototransduction: the olivary pretectal nucleus (OPN) and the suprachiasmatic nucleus (SCN). Our study population included 71 healthy individuals within an age range with known vulnerability to a delayed sleep phase (16.8-35.7 y, 37 males, 34 females). Pupillometry was performed to estimate functionality of the intrinsic melanopsin-signaling circuitry based on the OPN-mediated post-illumination pupil response (PIPR) to blue light. Sleep timing was quantified by estimating the SCN-mediated mid-sleep timing in three different ways in parallel: using a chronotype questionnaire, a sleep diary, and actigraphy. All three measures consistently showed that those individuals with a later mid-sleep timing had a more pronounced PIPR (0.03 < P < 0.05), indicating a stronger blue-light responsiveness of the intrinsic melanopsin-based phototransduction circuitry. Trait-like individual differences in the melanopsin phototransduction circuitry contribute to individual differences in sleep timing. Blue light-sensitive young individuals are more prone to delayed sleep. © 2016 Associated Professional Sleep Societies, LLC.

A late wake time phase delays the human dim light melatonin rhythm.

PubMed

Burgess, Helen J; Eastman, Charmane I

2006-03-13

Short sleep/dark durations, due to late bedtimes or early wake times or both, are common in modern society. We have previously shown that a series of days with a late bedtime phase delays the human dim light melatonin rhythm, as compared to a series of days with an early bedtime, despite a fixed wake time. Here we compared the effect of an early versus late wake time with a fixed bedtime on the human dim light melatonin rhythm. Fourteen healthy subjects experienced 2 weeks of short 6h nights with an early wake time fixed at their habitual weekday wake time and 2 weeks of long 9 h nights with a wake time that occurred 3h later than the early wake time, in counterbalanced order. We found that after 2 weeks with the late wake time, the dim light melatonin onset delayed by 2.4 h and the dim light melatonin offset delayed by 2.6 h (both p < 0.001), as compared to after 2 weeks with the early wake time. These results highlight the substantial influence that wake time, likely via the associated morning light exposure, has on the timing of the human circadian clock. Furthermore, the results suggest that when people truncate their sleep by waking early their circadian clocks phase advance and when people wake late their circadian clocks phase delay.

Delayed sleep phase: An important circadian subtype of sleep disturbance in bipolar disorders.

PubMed

Steinan, Mette Kvisten; Morken, Gunnar; Lagerberg, Trine V; Melle, Ingrid; Andreassen, Ole A; Vaaler, Arne E; Scott, Jan

2016-02-01

Theoretical models of Bipolar Disorder (BD) highlight that sleep disturbances may be a marker of underlying circadian dysregulation. However, few studies of sleep in BD have reported on the most prevalent circadian sleep abnormality, namely Delayed Sleep Phase (DSP). A cross-sectional study of 404 adults with BD who met published clinical criteria for insomnia, hypersomnia or DSP, and who had previously participated in a study of sleep in BD using a comprehensive structured interview assessment. About 10% of BD cases with a sleep problem met criteria for a DSP profile. The DSP group was younger and had a higher mean Body Mass Index (BMI) than the other groups. Also, DSP cases were significantly more likely to be prescribed mood stabilizers and antidepressant than insomnia cases. An exploratory analysis of selected symptom item ratings indicated that DSP was significantly more likely to be associated with impaired energy and activity levels. The cross-sectional design precludes examination of longitudinal changes. DSP is identified by sleep profile, not by diagnostic criteria or objective sleep records such as actigraphy. The study uses data from a previous study to identify and examine the DSP group. The DSP group identified in this study can be differentiated from hypersomnia and insomnia groups on the basis of clinical and demographic features. The association of DSP with younger age, higher BMI and impaired energy and activity also suggest that this clinical profile may be a good proxy for underlying circadian dysregulation. Copyright © 2015 Elsevier B.V. All rights reserved.

Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders.

PubMed

Auld, Fiona; Maschauer, Emily L; Morrison, Ian; Skene, Debra J; Riha, Renata L

2017-08-01

Melatonin is a physiological hormone involved in sleep timing and is currently used exogenously in the treatment of primary and secondary sleep disorders with empirical evidence of efficacy, but very little evidence from randomised, controlled studies. The aim of this meta-analysis was to assess the evidence base for the therapeutic effects of exogenous melatonin in treating primary sleep disorders. An electronic literature review search of MEDLINE (1950-present) Embase (1980- present), PsycINFO (1987- present), and Scopus (1990- present), along with a hand-searching of key journals was performed in July 2013 and then again in May 2015. This identified all studies that compared the effect of exogenous melatonin and placebo in patients with primary insomnia, delayed sleep phase syndrome, non 24-h sleep wake syndrome in people who are blind, and rapid eye movement-behaviour disorder. Meta-analyses were performed to determine the magnitude of effect in studies of melatonin in improving sleep. A total of 5030 studies were identified; of these citations, 12 were included for review based on the inclusion criteria of being: double or single-blind, randomised and controlled. Results from the meta-analyses showed the most convincing evidence for exogenous melatonin use was in reducing sleep onset latency in primary insomnia (p = 0.002), delayed sleep phase syndrome (p < 0.0001), and regulating the sleep-wake patterns in blind patients compared with placebo. These findings highlight the potential importance of melatonin in treating certain first degree sleep disorders. The development of large-scale, randomised, controlled trials is recommended to provide further evidence for therapeutic use of melatonin in a variety of sleep difficulties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spectral entropy analysis of the respiratory signal and its relationship with the cyclic alternating pattern during sleep

NASA Astrophysics Data System (ADS)

Reyes-Sanchez, E.; Alba, A.; Méndez, M. O.; Milioli, G.; Parrino, L.

2016-07-01

A-phases consist of transient cortical events that normally occur during NREM sleep and can be observed directly in the EEG signals. One particular kind of A-phases, namely, A3-phases are related to arousals from sleep during which increased activity in other systems (such as the cardiovascular and respiratory systems) can also be observed. This study aims to characterize disruptions in the oscillations of the airflow signal during A3-phases of sleep. Spectral entropy was used to quantify the bandwidth of the airflow signal, which under baseline conditions (prior to an A3-phase) resembles a sinusoidal wave with a frequency of about 0.25 Hz and has low spectral entropy values. It was found that during most A3-phases the spectral entropy increases significantly in 70% of the test subjects. These changes occur with higher probability during A3-phases that are longer than 10s, suggesting a delay between the onset of an A3-phase and the effect it has on the respiratory system.

The prevalence of probable delayed-sleep-phase syndrome in students from junior high school to university in Tottori, Japan.

PubMed

Hazama, Gen-i; Inoue, Yuichi; Kojima, Kazushige; Ueta, Toshiyuki; Nakagome, Kazuyuki

2008-09-01

Delayed sleep phase syndrome (DSPS) is a circadian rhythm sleep disorder with a typical onset in the second decade of life. DSPS is characterized by the sleep-onset insomnia and the difficulty in waking at the desired time in the morning. Although DSPS is associated with inability to attend school, the prevalence has been controversial. To elucidate a change in the prevalence of DSPS among young population, epidemiological survey was conducted on Japanese students. A total of 4,971 students of junior high school, senior high school, and university were enrolled in this cross sectional study in Tottori Prefecture. They answered anonymous screening questionnaire regarding school schedule, sleep hygiene and symptomatic items of sleep disorders. The prevalence of probable DSPS was estimated at 0.48% among the total subject students without gender difference. In university, the prevalence of the last year students showed the highest value (1.66%), while that of the first year students showed the lowest value (0.09%) among all school years from junior high school to university. The prevalence increased with advancing university school years. Thus, a considerable number of Japanese students are affected with DSPS. Senior students of university are more vulnerable to the disorder than younger students. Appropriate school schedule may decrease the mismatch between the individual's sleep-wake cycle and the school schedule. Promotion of a regular sleep habit is necessary to prevent DSPS among this population.

Resynchronization of circadian sleep-wake and temperature cycles in the squirrel monkey following phase shifts of the environmental light-dark cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wexler, D.B.; Moore-ede, M.C.

1986-12-01

Circadian rhythms in physiological and behavioral functions gradually resynchronize after phase shifts in environmental time cues. In order to characterize the rate of circadian resynchronization in a diurnal primate model, the temperature, locomotor activity, and polygraphically determined sleep-wake states were monitored in squirrel monkeys before and after 8-h phase shifts of an environmental light-dark cycle of 12 h light and 12 h dark (LD 12:12). For the temperature rhythm, resynchronization took 4 d after phase delay shift and 5 d after phase advance shift; for the rest-activity cycle, resynchronization times were 3 d and 6 d, respectively. The activity acrophasemore » shifted more rapidly than the temperature acrophase early in the post-delay shift interval, but this internal desynchronization between rhythms disappeared during the course of resynchronization. Further study of the early resynchronization process requires emphasis on identifying evoked effects and measuring circadian pacemaker function. 13 references.« less

Resynchronization of circadian sleep-wake and temperature cycles in the squirrel monkey following phase shifts of the environmental light-dark cycle

NASA Technical Reports Server (NTRS)

Wexler, D. B.; Moore-Ede, M. C.

1986-01-01

Circadian rhythms in physiological and behavioral functions gradually resynchronize after phase shifts in environmental time cues. In order to characterize the rate of circadian resynchronization in a diurnal primate model, the temperature, locomotor activity, and polygraphically determined sleep-wake states were monitored in squirrel monkeys before and after 8-h phase shifts of an environmental light-dark cycle of 12 h light and 12 h dark (LD 12:12). For the temperature rhythm, resynchronization took 4 d after phase delay shift and 5 d after phase advance shift; for the rest-activity cycle, resynchronization times were 3 d and 6 d, respectively. The activity acrophase shifted more rapidly than the temperature acrophase early in the post-delay shift interval, but this internal desynchronization between rhythms disappeared during the course of resynchronization. Further study of the early resynchronization process requires emphasis on identifying evoked effects and measuring circadian pacemaker function.

PPAR{alpha} is a potential therapeutic target of drugs to treat circadian rhythm sleep disorders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirai, Hidenori; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8502; Oishi, Katsutaka

Recent progress at the molecular level has revealed that nuclear receptors play an important role in the generation of mammalian circadian rhythms. To examine whether peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is involved in the regulation of circadian behavioral rhythms in mammals, we evaluated the locomotor activity of mice administered with the hypolipidemic PPAR{alpha} ligand, bezafibrate. Circadian locomotor activity was phase-advanced about 3 h in mice given bezafibrate under light-dark (LD) conditions. Transfer from LD to constant darkness did not change the onset of activity in these mice, suggesting that bezafibrate advanced the phase of the endogenous clock. Surprisingly, bezafibrate alsomore » advanced the phase in mice with lesions of the suprachiasmatic nucleus (SCN; the central clock in mammals). The circadian expression of clock genes such as period2, BMAL1, and Rev-erb{alpha} was also phase-advanced in various tissues (cortex, liver, and fat) without affecting the SCN. Bezafibrate also phase-advanced the activity phase that is delayed in model mice with delayed sleep phase syndrome (DSPS) due to a Clock gene mutation. Our results indicated that PPAR{alpha} is involved in circadian clock control independently of the SCN and that PPAR{alpha} could be a potent target of drugs to treat circadian rhythm sleep disorders including DSPS.« less

Estimating adolescent sleep need using dose-response modeling.

PubMed

Short, Michelle A; Weber, Nathan; Reynolds, Chelsea; Coussens, Scott; Carskadon, Mary A

2018-04-01

This study will (1) estimate the nightly sleep need of human adolescents, (2) determine the time course and severity of sleep-related deficits when sleep is reduced below this optimal quantity, and (3) determine whether sleep restriction perturbs the circadian system as well as the sleep homeostat. Thirty-four adolescents aged 15 to 17 years spent 10 days and nine nights in the sleep laboratory. Between two baseline nights and two recovery nights with 10 hours' time in bed (TIB) per night, participants experienced either severe sleep restriction (5-hour TIB), moderate sleep restriction (7.5-hour TIB), or no sleep restriction (10-hour TIB) for five nights. A 10-minute psychomotor vigilance task (PVT; lapse = response after 500 ms) and the Karolinska Sleepiness Scale were administered every 3 hours during wake. Salivary dim-light melatonin onset was calculated at baseline and after four nights of each sleep dose to estimate circadian phase. Dose-dependent deficits to sleep duration, circadian phase timing, lapses of attention, and subjective sleepiness occurred. Less TIB resulted in less sleep, more lapses of attention, greater subjective sleepiness, and larger circadian phase delays. Sleep need estimated from 10-hour TIB sleep opportunities was approximately 9 hours, while modeling PVT lapse data suggested that 9.35 hours of sleep is needed to maintain optimal sustained attention performance. Sleep restriction perturbs homeostatic and circadian systems, leading to dose-dependent deficits to sustained attention and sleepiness. Adolescents require more sleep for optimal functioning than typically obtained.

The treatment of early-morning awakening insomnia with 2 evenings of bright light.

PubMed

Lack, Leon; Wright, Helen; Kemp, Kristyn; Gibbon, Samantha

2005-05-01

To assess the effectiveness of brief bright-light therapy for the treatment of early-morning awakening insomnia. Twenty-four healthy adults with early-morning awakening insomnia were assigned to either the bright-light condition (2,500-lux white light) or the control (dim red light) condition. The circadian phase of rectal temperature and urinary melatonin rhythms were assessed with 26-hour constant routines before and after 2 evenings of light therapy. Sleep and daytime functioning were monitored using sleep diaries, activity monitors, and mood scales before light therapy and for 4 weeks during the follow-up period. While there were no significant circadian phase changes in the dim-light control group, the bright-light group had significant 2-hour phase delays of circadian temperature and melatonin rhythm. Compared to pretreatment measures, over the 4-week follow-up period, the bright-light group had a greater reduction of time awake after sleep onset, showed a trend toward waking later, and had a greater increase of total sleep time. Participants in the bright-light condition also tended to report greater reductions of negative daytime symptoms, including significantly fewer days of feeling depressed at the 4-week follow-up, as compared with the control group. Two evenings of bright-light exposure phase delayed the circadian rhythms of early-morning awakening insomniacs. It also improved diary and actigraphy sleep measures and improved some indexes of daytime functioning for up to 1 month after light exposure. The study suggests that a brief course of evening bright-light therapy can be an effective treatment for early-morning awakening insomniacs who have relatively phase advanced circadian rhythms.

Adjustment of sleep and the circadian temperature rhythm after flights across nine time zones

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Myhre, Grete; Graeber, R. Curtis; Lauber, John K.; Andersen, Harald T.

1989-01-01

The adjustment of sleep-wake patterns and the circadian temperature rhythm was monitored in nine Royal Norwegian Airforce volunteers operating P-3 aircraft during a westward training deployment across nine time zones. Subjects recorded all sleep and nap times, rated nightly sleep quality, and completed personality inventories. Rectal temperature, heart rate, and wrist activity were continuously monitored. Adjustment was slower after the return eastward flight than after the outbound westward flight. The eastward flight produced slower readjustment of sleep timing to local time and greater interindividual variability in the patterns of adjustment of sleep and temperature. One subject apparently exhibited resynchronization by partition, with the temperature rhythm undergoing the reciprocal 15-h delay. In contrast, average heart rates during sleep were significantly elevated only after westward flight. Interindividual differences in adjustment of the temperature rhythm were correlated with some of the personality measures. Larger phase delays in the overall temperature waveform (as measured on the 5th day after westward flight) were exhibited by extraverts, and less consistently by evening types.

Circadian polymorphisms in night owls, in bipolars, and in non-24-hour sleep cycles.

PubMed

Kripke, Daniel F; Klimecki, Walter T; Nievergelt, Caroline M; Rex, Katharine M; Murray, Sarah S; Shekhtman, Tatyana; Tranah, Gregory J; Loving, Richard T; Lee, Heon-Jeong; Rhee, Min Kyu; Shadan, Farhad F; Poceta, J Steven; Jamil, Shazia M; Kline, Lawrence E; Kelsoe, John R

2014-10-01

People called night owls habitually have late bedtimes and late times of arising, sometimes suffering a heritable circadian disturbance called delayed sleep phase syndrome (DSPS). Those with DSPS, those with more severe progressively-late non-24-hour sleep-wake cycles, and those with bipolar disorder may share genetic tendencies for slowed or delayed circadian cycles. We searched for polymorphisms associated with DSPS in a case-control study of DSPS research participants and a separate study of Sleep Center patients undergoing polysomnography. In 45 participants, we resequenced portions of 15 circadian genes to identify unknown polymorphisms that might be associated with DSPS, non-24-hour rhythms, or bipolar comorbidities. We then genotyped single nucleotide polymorphisms (SNPs) in both larger samples, using Illumina Golden Gate assays. Associations of SNPs with the DSPS phenotype and with the morningness-eveningness parametric phenotype were computed for both samples, then combined for meta-analyses. Delayed sleep and "eveningness" were inversely associated with loci in circadian genes NFIL3 (rs2482705) and RORC (rs3828057). A group of haplotypes overlapping BHLHE40 was associated with non-24-hour sleep-wake cycles, and less robustly, with delayed sleep and bipolar disorder (e.g., rs34883305, rs34870629, rs74439275, and rs3750275 were associated with n=37, p=4.58E-09, Bonferroni p=2.95E-06). Bright light and melatonin can palliate circadian disorders, and genetics may clarify the underlying circadian photoperiodic mechanisms. After further replication and identification of the causal polymorphisms, these findings may point to future treatments for DSPS, non-24-hour rhythms, and possibly bipolar disorder or depression.

Sleep-wake cycle in young and older persons with a lifetime history of mood disorders.

PubMed

Robillard, Rébecca; Naismith, Sharon L; Smith, Kristie Leigh; Rogers, Naomi L; White, Django; Terpening, Zoe; Ip, Tony K C; Hermens, Daniel F; Whitwell, Bradley; Scott, Elizabeth M; Hickie, Ian B

2014-01-01

Considering the marked changes in sleep and circadian rhythms across the lifespan, age may contribute to the heterogeneity in sleep-wake profiles linked to mood disorders. This study aimed to investigate the contributions of age and depression severity to sleep-wake disturbances. The Hamilton Depression Rating Scale (HDRS) was administered to assess current symptoms severity in 238 persons with a history of a mood disorder between 12 and 90 years of age (y.o.). Actigraphy was recorded over five to 22 days. Regression analyses and analyses of variance [age (12-19 y.o., 20-39 y.o., 40-59 y.o., and ≥ 60 y.o.) by depression severity (HDRS< and ≥ 8)] were conducted. The 12-19 y.o. and 20-39 y.o. groups had a delayed sleep schedule and acrophase compared to all other groups. The ≥ 60 y.o. group had a lower rhythmicity and amplitude (p ≤ .006) than the 12-19 y.o. group (p ≤ .046). Participants with a HDRS ≥ 8 spent longer time in bed, had later sleep offset times and had lower circadian rhythmicity than those with a HDRS<8 (p ≤ .036). Younger age and higher HDRS score correlated with later sleep onset and offset times, longer time in bed, higher WASO, lower sleep efficiency and later acrophase (p ≤ .023). Age was a significant predictor of delayed sleep and activity schedules (p ≤ .001). The profile of sleep-wake cycle disturbances associated with mood disorders changes with age, with prominent sleep phase delay during youth and reduced circadian strength in older persons. Conversely, disruptions in sleep consolidation seem more stable across age.

Dysregulated sleep-wake cycles in young people are associated with emerging stages of major mental disorders.

PubMed

Scott, Elizabeth M; Robillard, Rébecca; Hermens, Daniel F; Naismith, Sharon L; Rogers, Naomi L; Ip, Tony K C; White, Django; Guastella, Adam; Whitwell, Bradley; Smith, Kristie Leigh; Hickie, Ian B

2016-02-01

To determine if disturbed sleep-wake cycle patterns in young people with evolving mental disorder are associated with stages of illness. The sleep-wake cycle was monitored using actigraphy across 4 to 22 days. Participants (21 healthy controls and 154 persons seeking help for mental health problems) were aged between 12 and 30 years. Those persons seeking mental health care were categorized as having mild symptoms (stage 1a), an 'attenuated syndrome' (stage 1b) or an 'established mental disorder' (stage 2+). The proportions of individuals with a delayed weekdays sleep schedule increased progressively across illness stages: 9.5% of controls, 11.1% of stage 1a, 25.6% of stage 1b, and 50.0% of stage 2+ (χ(2) (3 d.f.) = 18.4, P < 0.001). A similar pattern was found for weekends (χ(2) (3 d.f.) = 7.6, P = 0.048). Compared with controls, stage 1b participants had later sleep onset on weekends (P = 0.015), and participants at stages 1b and 2+ had later sleep offset on both weekdays and weekends (P < 0.020). Compared with controls, all participants with mental disorders had more wake after sleep onset (P < 0.029) and those at stages 1a and 2+ had lower sleep efficiency (P < 0.040). Older age, medicated status and later weekdays sleep offset were found to be the three strongest correlates of later versus earlier clinical stages. In relation to clinical staging of common mental disorders in young people, the extent of delayed sleep phase is associated with more severe or persistent phases of illness. © 2014 Wiley Publishing Asia Pty Ltd.

Sleep during an Antarctic summer expedition: new light on "polar insomnia".

PubMed

Pattyn, Nathalie; Mairesse, Olivier; Cortoos, Aisha; Marcoen, Nele; Neyt, Xavier; Meeusen, Romain

2017-04-01

Sleep complaints are consistently cited as the most prominent health and well-being problem in Arctic and Antarctic expeditions, without clear evidence to identify the causal mechanisms. The present investigation aimed at studying sleep and determining circadian regulation and mood during a 4-mo Antarctic summer expedition. All data collection was performed during the continuous illumination of the Antarctic summer. After an habituation night and acclimatization to the environment (3 wk), ambulatory polysomnography (PSG) was performed in 21 healthy male subjects, free of medication. An 18-h profile (saliva sampling every 2 h) of cortisol and melatonin was assessed. Mood, sleepiness, and subjective sleep quality were assessed, and the psychomotor vigilance task was administered. PSG showed, in addition to high sleep fragmentation, a major decrease in slow-wave sleep (SWS) and an increase in stage R sleep. Furthermore, the ultradian rhythmicity of sleep was altered, with SWS occurring mainly at the end of the night and stage R sleep at the beginning. Cortisol secretion profiles were normal; melatonin secretion, however, showed a severe phase delay. There were no mood alterations according to the Profile of Mood States scores, but the psychomotor vigilance test showed an impaired vigilance performance. These results confirm previous reports on "polar insomnia", the decrease in SWS, and present novel insight, the disturbed ultradian sleep structure. A hypothesis is formulated linking the prolonged SWS latency to the phase delay in melatonin. NEW & NOTEWORTHY The present paper presents a rare body of work on sleep and sleep wake regulation in the extreme environment of an Antarctic expedition, documenting the effects of constant illumination on sleep, mood, and chronobiology. For applied research, these results suggest the potential efficiency of melatonin supplementation in similar deployments. For fundamental research, these results warrant further investigation of the potential link between melatonin secretion and the onset of slow-wave sleep. Copyright © 2017 the American Physiological Society.

The phase shift hypothesis for the circadian component of winter depression

PubMed Central

Lewy, Alfred J.; Rough, Jennifer N.; Songer, Jeannine B.; Mishra, Neelam; Yuhas, Krista; Emens, Jonathan S.

2007-01-01

The finding that bright light can suppress melatonin production led to the study of two situations, indeed, models, of light deprivation: totally blind people and winterdepressives. The leading hypothesis for winter depression (seasonal affective disorder, or SAD) is the phase shift hypothesis (PSH). The PSH was recently established in a study in which SAD patients were given low-dose melatonin in the afternoon/evening to cause phase advances, or in the morning to cause phase delays, or placebo. The prototypical phase-delayed patient as well as the smaller subgroup of phase-advanced patients, optimally responded to melatonin given at the correct time. Symptom severity improved as circadian misalignment was corrected. Orcadian misalignment is best measured as the time interval between the dim light melatonin onset (DLMO) and mid-sleep. Using the operational definition of the plasma DLMO as the interpolated time when melatonin levels continuously rise above the threshold of 10 pglmL, the average interval between DLMO and mid-sleep in healthy controls is 6 hours, which is associated with optimal mood in SAD patients. PMID:17969866

Academic performance in adolescents with delayed sleep phase.

PubMed

Sivertsen, Børge; Glozier, Nick; Harvey, Allison G; Hysing, Mari

2015-09-01

Delayed sleep phase (DSP) in adolescence has been linked to reduced academic performance, but there are few population-based studies examining this association using validated sleep measures and objective outcomes. The youth@hordaland-survey, a large population-based study from Norway conducted in 2012, surveyed 8347 high-school students aged 16-19 years (54% girls). DSP was assessed by self-report sleep measures, and it was operationalized according to the International Classification of Sleep Disorders - Second Edition. School performance (grade point average, GPA) was obtained from official administrative registries, and it was linked individually to health data. DSP was associated with increased odds for poor school performance. After adjusting for age and gender, DSP was associated with a threefold increased odds of poor GPA (lowest quartile) [odds ratio (OR) = 2.95; 95% confidence interval (CI): 2.03-4.30], and adjustment for sociodemographics and lifestyle factors did not, or only slightly, attenuate this association. Adjustment for nonattendance at school reduced the association substantially, and in the fully adjusted model, the effect of DSP on poor academic performance was reduced to a non-significant level. Mediation analyses confirmed both direct and significant indirect effects of DSP on school performance based on school absence, daytime sleepiness, and sleep duration. Poor academic performance may reflect an independent effect of underlying circadian disruption, which in part could be mediated by school attendance, as well as daytime sleepiness and short sleep duration. This suggests that careful assessment of sleep is warranted in addressing educational difficulties. Copyright © 2015 Elsevier B.V. All rights reserved.

A three pulse phase response curve to three milligrams of melatonin in humans

PubMed Central

Burgess, Helen J; Revell, Victoria L; Eastman, Charmane I

2008-01-01

Exogenous melatonin is increasingly used for its phase shifting and soporific effects. We generated a three pulse phase response curve (PRC) to exogenous melatonin (3 mg) by administering it to free-running subjects. Young healthy subjects (n = 27) participated in two 5 day laboratory sessions, each preceded by at least a week of habitual, but fixed sleep. Each 5 day laboratory session started and ended with a phase assessment to measure the circadian rhythm of endogenous melatonin in dim light using 30 min saliva samples. In between were three days in an ultradian dim light (< 150 lux)–dark cycle (LD 2.5 : 1.5) during which each subject took one pill per day at the same clock time (3 mg melatonin or placebo, double blind, counterbalanced). Each individual's phase shift to exogenous melatonin was corrected by subtracting their phase shift to placebo (a free-run). The resulting PRC has a phase advance portion peaking about 5 h before the dim light melatonin onset, in the afternoon. The phase delay portion peaks about 11 h after the dim light melatonin onset, shortly after the usual time of morning awakening. A dead zone of minimal phase shifts occurred around the first half of habitual sleep. The fitted maximum advance and delay shifts were 1.8 h and 1.3 h, respectively. This new PRC will aid in determining the optimal time to administer exogenous melatonin to achieve desired phase shifts and demonstrates that using exogenous melatonin as a sleep aid at night has minimal phase shifting effects. PMID:18006583

Circadian Rhythm and Sleep During Prolonged Antarctic Residence at Chinese Zhongshan Station.

PubMed

Chen, Nan; Wu, Quan; Xiong, Yanlei; Chen, Guang; Song, Dandan; Xu, Chengli

2016-12-01

Residence at Zhongshan Station (69°22'24″S, 76°22'40″E) for over 1 year exposes winter-over members to marked changes of light-dark cycle, ranging from the constant daylight of polar days to the constant darkness of polar nights, in addition to geographic and social isolation. This extreme photoperiodic environment may increase the risk of sleep disturbances and circadian desynchrony. The aim of this study was to investigate the circadian rhythm and sleep phase of Chinese winter-over expeditioners at Zhongshan Station. This study was conducted on 17 healthy male participants before departure from Shanghai and during residence at Zhongshan Station for 1 year (before winter, mid-winter, and end of winter). Sequential urine samples over 48 hours were obtained, 6-sulphatoxymelatonin in urine was assessed, and the circadian rhythm was analyzed by a cosine curve-fitting method. Participants' sleep parameters were obtained from wrist actigraphy and sleep logs. Morningness-Eveningness Questionnaire and Seasonal Pattern Assessment Questionnaire were completed. The acrophase of 6-sulphatoxymelatonin rhythm, sleep onset, sleep offset, and mid-sleep time were delayed significantly (P < .05) in Antarctica relative to departure values. The subjects had greater eveningness preference (P < .05) in mid-winter in Antarctica. The Global Seasonality Score and the prevalence of subsyndromal seasonal affective disorder increased (P < .05) during winter. Our results indicate that during polar nights Chinese expeditioners experienced the following problems: delayed circadian rhythm and sleep phase, later chronotype, and incidence of subsyndromal seasonal affective disorder. An appropriate combination of artificial bright light during dark winter months and a strict social schedule are recommended in a winter-over station in Antarctica. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Melatonin and cortisol assessment of circadian shifts in astronauts before flight

NASA Technical Reports Server (NTRS)

Whitson, P. A.; Putcha, L.; Chen, Y. M.; Baker, E.

1995-01-01

Melatonin and cortisol were measured in saliva and urine samples to assess the effectiveness of a 7-day protocol combining bright-light exposure with sleep shifting in eliciting a 12-hr phase-shift delay in eight U.S. Space Shuttle astronauts before launch. Baseline acrophases for 15 control subjects with normal sleep-wake cycles were as follows: cortisol (saliva) at 0700 (0730 in urine); melatonin (saliva) at 0130 (6-hydroxymelatonin sulfate at 0230 in urine). Acrophases of the astronaut group fell within 2.5 hr of these values before the treatment protocols were begun. During the bright-light and sleep-shifting treatments, both absolute melatonin production and melatonin rhythmicity were diminished during the first 3 treatment days; total daily cortisol levels remained constant throughout the treatment. By the fourth to sixth day of the 7-day protocol, seven of the eight crew members showed phase delays in all four measures that fell within 2 hr of the expected 11- to 12-hr shift. Although cortisol and melatonin rhythms each corresponded with the phase shift, the rhythms in these two hormones did not correspond with each other during the transition.

Melatonin and cortisol assessment of circadian shifts in astronauts before flight.

PubMed

Whitson, P A; Putcha, L; Chen, Y M; Baker, E

1995-04-01

Melatonin and cortisol were measured in saliva and urine samples to assess the effectiveness of a 7-day protocol combining bright-light exposure with sleep shifting in eliciting a 12-hr phase-shift delay in eight U.S. Space Shuttle astronauts before launch. Baseline acrophases for 15 control subjects with normal sleep-wake cycles were as follows: cortisol (saliva) at 0700 (0730 in urine); melatonin (saliva) at 0130 (6-hydroxymelatonin sulfate at 0230 in urine). Acrophases of the astronaut group fell within 2.5 hr of these values before the treatment protocols were begun. During the bright-light and sleep-shifting treatments, both absolute melatonin production and melatonin rhythmicity were diminished during the first 3 treatment days; total daily cortisol levels remained constant throughout the treatment. By the fourth to sixth day of the 7-day protocol, seven of the eight crew members showed phase delays in all four measures that fell within 2 hr of the expected 11- to 12-hr shift. Although cortisol and melatonin rhythms each corresponded with the phase shift, the rhythms in these two hormones did not correspond with each other during the transition.

Sleep in university students across years of university education and gender influences.

PubMed

Manzar, Md Dilshad; Zannat, Wassilatul; Kaur, Manpreet; Hussain, M Ejaz

2015-08-01

Assessment of the influence of gender and increasing years at university on sleep health of students. Four hundred and eighteen students from different streams across years of undergraduate to postgraduate courses participated. Descriptive statistics, test of differences, and correlation were used. The sleep health data comprised of subjective evaluation using a questionnaire and personal interviews. Overall, 43.1% had sleep problems, females were more affected (51.67% vs. 48.33% in males) but were early bed goers. The prevalence of circadian rhythm sleep disorder (11.6% vs. 9.5%) and delayed sleep phase syndrome (4.5% vs. 2.7%) was slightly higher in males. The daytime dysfunction and hypnotic use significantly differed in students of the same class among gender. Bedtime got significantly delayed along years [H(2)=29.769, p<0.001], and hypnotic use [H(2)=8.807, p=0.012] differed significantly among them. The moderate-very strong correlational statistics among sleep health elements was very similar across gender and years of university education. However, more pronounced influence of years of university education than gender was seen in the significant differences for correlated correlation among sleep health parameters. Gender and years of university education influence sleep among university students both separately and concomitantly.

Sleep-dependent consolidation patterns reveal insights into episodic memory structure.

PubMed

Oyanedel, Carlos N; Sawangjit, Anuck; Born, Jan; Inostroza, Marion

2018-05-18

Episodic memory formation is considered a genuinely hippocampal function. Its study in rodents has relied on two different task paradigms, i.e. the so called "what-where-when" (WW-When) task and "what-where-which" (WW-Which) task. The WW-When task aims to assess the memory for an episode as an event bound into its context defined by spatial and distinct temporal information, the WW-Which task lacks the temporal component and introduces, instead, an "occasion setter" marking the broader contextual configuration in which the event occurred. Whether both tasks measure episodic memory in an equivalent manner in terms of recollection has been controversially discussed. Here, we compared in two groups of rats the consolidating effects of sleep on episodic-like memory between both task paradigms. Sampling and test phases were separated by a 90-min morning retention interval which did or did not allow for spontaneous sleep. Results show that sleep is crucial for the consolidation of the memory on both tasks. However, consolidating effects of sleep were stronger for the WW-Which than WW-When task. Comparing performance during the post-sleep test phase revealed that WW-When memory only gradually emerged during the 3-min test period whereas WW-Which memory was readily expressed already from the first minute onward. Separate analysis of the temporal and spatial components of WW-When performance showed that the delayed episodic memory on this task originated from the temporal component which also did not emerge until the third minute of the test phase, whereas the spatial component already showed up in the first minute. In conclusion, sleep differentially affects consolidation on the two episodic-like memory tasks, with the delayed expression of WW-When memory after sleep resulting from preferential coverage of temporal aspects by this task. Copyright © 2018. Published by Elsevier Inc.

Individual Differences in Sleep Timing Relate to Melanopsin-Based Phototransduction in Healthy Adolescents and Young Adults

PubMed Central

van der Meijden, Wisse P.; Van Someren, Jamie L.; te Lindert, Bart H.W.; Bruijel, Jessica; van Oosterhout, Floor; Coppens, Joris E.; Kalsbeek, Andries; Cajochen, Christian; Bourgin, Patrice; Van Someren, Eus J.W.

2016-01-01

Study Objectives: Individual differences in sleep timing have been widely recognized and are of particular relevance in adolescents and young adults who often show mild to severely delayed sleep. The biological mechanisms underlying the between-subject variance remain to be determined. Recent human genetics studies showed an association between sleep timing and melanopsin gene variation, but support for functional effects on downstream pathways and behavior was not demonstrated before. We therefore investigated the association between the autonomic (i.e., pupil diameter) and behavioral (i.e., sleep timing) readouts of two different downstream brain areas, both affected by the same melanopsin-dependent retinal phototransduction: the olivary pretectal nucleus (OPN) and the suprachiasmatic nucleus (SCN). Methods: Our study population included 71 healthy individuals within an age range with known vulnerability to a delayed sleep phase (16.8–35.7 y, 37 males, 34 females). Pupillometry was performed to estimate functionality of the intrinsic melanopsin-signaling circuitry based on the OPN-mediated post-illumination pupil response (PIPR) to blue light. Sleep timing was quantified by estimating the SCN-mediated mid-sleep timing in three different ways in parallel: using a chronotype questionnaire, a sleep diary, and actigraphy. Results: All three measures consistently showed that those individuals with a later mid-sleep timing had a more pronounced PIPR (0.03 < P < 0.05), indicating a stronger blue-light responsiveness of the intrinsic melanopsin-based phototransduction circuitry. Conclusions: Trait-like individual differences in the melanopsin phototransduction circuitry contribute to individual differences in sleep timing. Blue light-sensitive young individuals are more prone to delayed sleep. Citation: van der Meijden WP, Van Someren JL; te Lindert BH, Bruijel J, van Oosterhout F, Coppens JE, Kalsbeek A, Cajochen C, Bourgin P, Van Someren EJ. Individual differences in sleep timing relate to melanopsin-based phototransduction in healthy adolescents and young adults. SLEEP 2016;39(6):1305–1310. PMID:27091519

A randomized controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent delayed sleep phase disorder.

PubMed

Gradisar, Michael; Dohnt, Hayley; Gardner, Greg; Paine, Sarah; Starkey, Karina; Menne, Annemarie; Slater, Amy; Wright, Helen; Hudson, Jennifer L; Weaver, Edward; Trenowden, Sophie

2011-12-01

To evaluate cognitive-behavior therapy plus bright light therapy (CBT plus BLT) for adolescents diagnosed with delayed sleep phase disorder (DSPD). Randomized controlled trial of CBT plus BLT vs. waitlist (WL) control with comparisons at pre- and post-treatment. There was 6-month follow-up for the CBT plus BLT group only. Flinders University Child & Adolescent Sleep Clinic, Adelaide, South Australia. 49 adolescents (mean age 14.6 ± 1.0 y, 53% males) diagnosed with DSPD; mean chronicity 4 y 8 months; 16% not attending school. Eighteen percent of adolescents dropped out of the study (CBT plus BLT: N = 23 vs. WL: N = 17). CBT plus BLT consisted of 6 individual sessions, including morning bright light therapy to advance adolescents' circadian rhythms, and cognitive restructuring and sleep education to target associated insomnia and sleep hygiene. DSPD diagnosis was performed via a clinical interview and 7-day sleep diary. Measurements at each time-point included online sleep diaries and scales measuring sleepiness, fatigue, and depression symptoms. Compared to WL, moderate-to-large improvements (d = 0.65-1.24) were found at post-treatment for CBT plus BLT adolescents, including reduced sleep latency, earlier sleep onset and rise times, total sleep time (school nights), wake after sleep onset, sleepiness, and fatigue. At 6-month follow-up (N = 15), small-to-large improvements (d = 0.24-1.53) continued for CBT plus BLT adolescents, with effects found for all measures. Significantly fewer adolescents receiving CBT plus BLT met DPSD criteria at post-treatment (WL = 82% vs. CBT plus BLT = 13%, P < 0.0001), yet 13% still met DSPD criteria at the 6-month follow-up. CBT plus BLT for adolescent DSPD is effective for improving multiple sleep and daytime impairments in the immediate and long-term. Studies evaluating the treatment effectiveness of each treatment component are needed. Australia-New Zealand Trials Registry Number: ACTRN12610001041044.

Association between delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan.

PubMed

Kitamura, Shingo; Enomoto, Minori; Kamei, Yuichi; Inada, Naoko; Moriwaki, Aiko; Kamio, Yoko; Mishima, Kazuo

2015-03-13

Although delayed sleep timing causes many socio-psycho-biological problems such as sleep loss, excessive daytime sleepiness, obesity, and impaired daytime neurocognitive performance in adults, there are insufficient data showing the clinical significance of a 'night owl lifestyle' in early life. This study examined the association between habitual delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan. Parents/caregivers of 708 community-dwelling 2-year-old children in Nishitokyo City, Tokyo, participated in the study. The participants answered a questionnaire to evaluate their child's sleep habits and sleep-related problems for the past 1 month. Of the 425 children for whom complete data were collected, 90 (21.2%) went to bed at 22:00 or later. Children with delayed bedtime showed significantly more irregular bedtime, delayed wake time, shorter total sleep time, and difficulty in initiating and terminating sleep. Although this relationship indicated the presence of sleep debt in children with delayed bedtime, sleep onset latency did not differ between children with earlier bedtime and those with delayed bedtime. Rather, delayed bedtime was significantly associated with bedtime resistance and problems in the morning even when adjusting for nighttime and daytime sleep time. Even in 2-year-old children, delayed bedtime was associated with various sleep-related problems. The causal factors may include diminished homeostatic sleep drive due to prolonged daytime nap as well as diurnal preference (morning or night type) regulated by the biological clock.

Wearing blue light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial.

PubMed

Esaki, Yuichi; Kitajima, Tsuyoshi; Ito, Yasuhiro; Koike, Shigefumi; Nakao, Yasumi; Tsuchiya, Akiko; Hirose, Marina; Iwata, Nakao

2016-01-01

It has been recently discovered that blue wavelengths form the portion of the visible electromagnetic spectrum that most potently regulates circadian rhythm. We investigated the effect of blue light-blocking glasses in subjects with delayed sleep phase disorder (DSPD). This open-label trial was conducted over 4 consecutive weeks. The DSPD patients were instructed to wear blue light-blocking amber glasses from 21:00 p.m. to bedtime, every evening for 2 weeks. To ascertain the outcome of this intervention, we measured dim light melatonin onset (DLMO) and actigraphic sleep data at baseline and after the treatment. Nine consecutive DSPD patients participated in this study. Most subjects could complete the treatment with the exception of one patient who hoped for changing to drug therapy before the treatment was completed. The patients who used amber lens showed an advance of 78 min in DLMO value, although the change was not statistically significant (p = 0.145). Nevertheless, the sleep onset time measured by actigraph was advanced by 132 min after the treatment (p = 0.034). These data suggest that wearing amber lenses may be an effective and safe intervention for the patients with DSPD. These findings also warrant replication in a larger patient cohort with controlled observations.

Sleep-Wake Patterns and Sleep Disturbance among Hong Kong Chinese Adolescents

PubMed Central

Chung, Ka-Fai; Cheung, Miao-Miao

2008-01-01

Study objectives: To determine sleep-wake patterns and evaluate sleep disturbance in Hong Kong adolescents; to identify factors that are associated with sleep disturbance; and to examine the relationship of sleep-wake variables and academic performance. Design and Setting: A school-based cross-sectional survey. Participants: Sample included 1629 adolescents aged 12 to 19 years. Measurements and Results: Self-report questionnaires, including sleep-wake habit questionnaire, Sleep Quality Index, Morningness/Eveningness scale, Epworth Sleepiness Scale, Perceived Stress Scale, academic performance, and personal data were administered. The average school-night bedtime was 23:24, and total sleep time was 7.3 hr. During weekends, the average bedtime and rise time was delayed by 64 min and 195 min, respectively. The prevalence of sleep disturbances occurring ≥3 days per week in the preceding 3 months were: difficulty falling asleep (5.6%), waking up during the night (7.2%), and waking up too early in the morning (10.4%). The prevalence of ≥1 of these three symptoms was 19.1%. Stepwise regression analyses revealed that circadian phase preference was the most significant predictor for school night bedtime, weekend oversleep, and daytime sleepiness. Perceived stress was the most significant risk factor for sleep disturbance. Students with marginal academic performance reported later bedtimes and shorter sleep during school nights, greater weekend delays in bedtime, and more daytime sleepiness than those with better grades. Conclusion: The prevalence of sleep deprivation and sleep disturbance among Hong Kong adolescents is comparable to those found in other countries. An intervention program for sleep problems in adolescents should be considered. Citation: Chung KF; Cheung MM. Sleep-wake patterns and sleep disturbance among Hong Kong Chinese adolescents. SLEEP 2008;31(2):185–194. PMID:18274265

Effect of Aptensio XR (Methylphenidate HCl Extended-Release) Capsules on Sleep in Children with Attention-Deficit/Hyperactivity Disorder.

PubMed

Owens, Judith; Weiss, Margaret; Nordbrock, Earl; Mattingly, Greg; Wigal, Sharon; Greenhill, Laurence L; Chang, Wei-Wei; Childress, Ann; Kupper, Robert J; Adjei, Akwete

2016-12-01

To evaluate measures of sleep (exploratory endpoints) in two pivotal studies of a multilayer bead extended-release methylphenidate (MPH-MLR) treatment of attention-deficit/hyperactivity disorder in children. Study 1 evaluated the time course of response to MPH-MLR (n = 26) patients in an analog classroom setting through four phases: screening (≤28 days), open label (OL) dose optimization (4 weeks), double-blind (DB) crossover (2 weeks; placebo vs. optimized dose), and follow-up call. Study 2 was a forced-dose parallel evaluation of MPH-MLR (n = 230) in four phases: screening (≤28 days), DB (1 week; placebo or MPH-MLR 10, 15, 20, or 40 mg/day), OL dose optimization (11 weeks), and follow-up call. Sleep was evaluated by parents using the Children's or Adolescent Sleep Habits Questionnaire (CSHQ or ASHQ) during the DB and OL phases. DB analysis: Study 1 (crossover), analysis of variance; Study 2, analysis of covariance. OL analysis: paired t-test. DB: treatments were significantly different in Study 1 only for CSHQ Sleep Onset Delay (MPH-MLR, 1.90 vs. placebo, 1.34; p = 0.0046, placebo was better), and Study 2 for CSHQ Parasomnias (treatment, p = 0.0295), but no MPH-MLR treatment was different from placebo (pairwise MPH-MLR treatment to placebo, all p ≥ 0.170). OL: CSHQ total and Bedtime Resistance, Sleep Duration, Sleep Anxiety, Night Wakings, Parasomnias, and Sleep-disordered Breathing subscales decreased (improved, Study 1) significant only for CSHQ Night Wakings (p < 0.05); in Study 2 CSHQ total and Bedtime Resistance, Sleep Duration, Night Wakings, Parasomnias, and Daytime Sleepiness, and ASHQ total, Bedtime, Sleep Behavior, and Morning Waking all significantly improved (p < 0.05). In both studies, there was minimal negative impact of MPH-MLR on sleep during the brief DB phase and none during the longer duration OL phase. Some measures of sleep improved with optimized MPH-MLR dose.

Circadian phase resetting in older people by ocular bright light exposure.

PubMed

Klerman, E B; Duffy, J F; Dijk, D J; Czeisler, C A

2001-01-01

Aging is associated with frequent complaints about earlier bedtimes and waketimes. These changes in sleep timing are associated with an earlier timing of multiple endogenous rhythms, including core body temperature (CBT) and plasma melatonin, driven by the circadian pacemaker. One possible cause of the age-related shift of endogenous circadian rhythms and the timing of sleep relative to clock time is a change in the phase-shifting capacity of the circadian pacemaker in response to the environmental light-dark cycle, the principal synchronizer of the human circadian system. We studied the response of the circadian system of 24 older men and women and 23 young men to scheduled exposure to ocular bright light stimuli. Light stimuli were 5 hours in duration, administered for 3 consecutive days at an illuminance of approximately 10,000 lux. Light stimuli were scheduled 1.5 or 3.5 hours after the CBT nadir to induce shifts of endogenous circadian pacemaker to an earlier hour (phase advances) or were scheduled 1.5 hours before the CBT nadir to induce shifts to a later hour (phase delays). The rhythms of CBT and plasma melatonin assessed under constant conditions served as markers of circadian phase. Bright light stimuli elicited robust responses of the circadian timing system in older people; both phase advances and phase delays were induced. The magnitude of the phase delays did not differ significantly between older and younger individuals, but the phase advances were significantly attenuated in older people. The attenuated response to light stimuli that induce phase advances does not explain the advanced phase of the circadian pacemaker in older people. The maintained responsiveness of the circadian pacemaker to light implies that scheduled bright light exposure can be used to treat circadian phase disturbances in older people.

Role of the melatonin system in the control of sleep: therapeutic implications.

PubMed

Pandi-Perumal, Seithikurippu R; Srinivasan, Venkatramanujan; Spence, D Warren; Cardinali, Daniel P

2007-01-01

The circadian rhythm of pineal melatonin secretion, which is controlled by the suprachiasmatic nucleus (SCN), is reflective of mechanisms that are involved in the control of the sleep/wake cycle. Melatonin can influence sleep-promoting and sleep/wake rhythm-regulating actions through the specific activation of MT(1) (melatonin 1a) and MT(2) (melatonin 1b) receptors, the two major melatonin receptor subtypes found in mammals. Both receptors are highly concentrated in the SCN. In diurnal animals, exogenous melatonin induces sleep over a wide range of doses. In healthy humans, melatonin also induces sleep, although its maximum hypnotic effectiveness, as shown by studies of the timing of dose administration, is influenced by the circadian phase. In both young and elderly individuals with primary insomnia, nocturnal plasma melatonin levels tend to be lower than those in healthy controls. There are data indicating that, in affected individuals, melatonin therapy may be beneficial for ameliorating insomnia symptoms. Melatonin has been successfully used to treat insomnia in children with attention-deficit hyperactivity disorder or autism, as well as in other neurodevelopmental disorders in which sleep disturbance is commonly reported. In circadian rhythm sleep disorders, such as delayed sleep-phase syndrome, melatonin can significantly advance the phase of the sleep/wake rhythm. Similarly, among shift workers or individuals experiencing jet lag, melatonin is beneficial for promoting adjustment to work schedules and improving sleep quality. The hypnotic and rhythm-regulating properties of melatonin and its agonists (ramelteon, agomelatine) make them an important addition to the armamentarium of drugs for treating primary and secondary insomnia and circadian rhythm sleep disorders.

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise.

PubMed

Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A

2016-02-26

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) bright light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.

Sleep can eliminate list-method directed forgetting.

PubMed

Abel, Magdalena; Bäuml, Karl-Heinz T

2013-05-01

Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when cued to do so. We applied the list-method directed forgetting task and assessed memory performance after 3 delay intervals. Directed forgetting was present after a short 20-min delay and after a 12-hr delay filled with diurnal wakefulness; in contrast, the forgetting was absent after a 12-hr delay that included regular nocturnal sleep. Successful directed forgetting after a delay thus can depend on whether sleep or wakefulness follows upon encoding: When wakefulness follows upon encoding, the forgetting can be successful; when sleep follows upon encoding, no forgetting may arise. Connections of the results to recent studies on the interplay between forgetting and sleep are discussed.

Preliminary evidence that light through the eyelids can suppress melatonin and phase shift dim light melatonin onset

PubMed Central

2012-01-01

Background A previous study reported a method for measuring the spectral transmittance of individual human eyelids. A prototype light mask using narrow-band “green” light (λmax = 527 nm) was used to deliver light through closed eyelids in two within-subjects studies. The first study investigated whether an individual-specific light dose could suppress melatonin by 40% through the closed eyelid without disrupting sleep. The light doses were delivered at three times during the night: 1) beginning (while subjects were awake), 2) middle (during rapid eye movement (REM) sleep), and 3) end (during non-REM sleep). The second study investigated whether two individual-specific light doses expected to suppress melatonin by 30% and 60% and delivered through subjects’ closed eyelids before the time of their predicted minimum core body temperature would phase delay the timing of their dim light melatonin onset (DLMO). Findings Compared to a dark control night, light delivered through eyelids suppressed melatonin by 36% (p = 0.01) after 60-minute light exposure at the beginning, 45% (p = 0.01) at the middle, and 56% (p < 0.0001) at the end of the night. In the second study, compared to a dark control night, melatonin was suppressed by 25% (p = 0.03) and by 45% (p = 0.009) and circadian phase, as measured by DLMO, was delayed by 17 minutes (p = 0.03) and 71 minutes (ns) after 60-minute exposures to light levels 1 and 2, respectively. Conclusions These studies demonstrate that individual-specific doses of light delivered through closed eyelids can suppress melatonin and phase shift DLMO and may be used to treat circadian sleep disorders. PMID:22564396

Preliminary evidence that light through the eyelids can suppress melatonin and phase shift dim light melatonin onset.

PubMed

Figueiro, Mariana G; Rea, Mark S

2012-05-07

A previous study reported a method for measuring the spectral transmittance of individual human eyelids. A prototype light mask using narrow-band "green" light (λmax = 527 nm) was used to deliver light through closed eyelids in two within-subjects studies. The first study investigated whether an individual-specific light dose could suppress melatonin by 40% through the closed eyelid without disrupting sleep. The light doses were delivered at three times during the night: 1) beginning (while subjects were awake), 2) middle (during rapid eye movement (REM) sleep), and 3) end (during non-REM sleep). The second study investigated whether two individual-specific light doses expected to suppress melatonin by 30% and 60% and delivered through subjects' closed eyelids before the time of their predicted minimum core body temperature would phase delay the timing of their dim light melatonin onset (DLMO). Compared to a dark control night, light delivered through eyelids suppressed melatonin by 36% (p = 0.01) after 60-minute light exposure at the beginning, 45% (p = 0.01) at the middle, and 56% (p < 0.0001) at the end of the night. In the second study, compared to a dark control night, melatonin was suppressed by 25% (p = 0.03) and by 45% (p = 0.009) and circadian phase, as measured by DLMO, was delayed by 17 minutes (p = 0.03) and 71 minutes (ns) after 60-minute exposures to light levels 1 and 2, respectively. These studies demonstrate that individual-specific doses of light delivered through closed eyelids can suppress melatonin and phase shift DLMO and may be used to treat circadian sleep disorders.

Load compensation as a function of state during sleep onset.

PubMed

Gora, J; Kay, A; Colrain, I M; Kleiman, J; Trinder, J

1998-06-01

Ventilation decreases and airway resistance increases with the loss of electroencephalogram alpha activity at sleep onset. The aim of this study was to determine whether reflexive load compensation is lost immediately on the loss of alpha activity. Six healthy male subjects were studied under two conditions (load and control-no load), in three states (continuous alpha, continuous theta, and immediately after a transition from alpha to theta), and in two phases (early and late sleep onset). Ventilation and respiratory timing were measured. A comparison of loaded with control conditions indicated that loading had no effect on inspiratory minute ventilation during continuous alpha (differential effect of 0.00 l/min) and only a small, nonsignificant effect in theta immediately after phase 2 transitions (0.31 l/min), indicating a preservation of load compensation at these times. However, there were significant decreases in inspiratory minute ventilation on loaded trials during continuous theta in phase 2 (0.77 l/min) and phase 3 (1.15 l/min) and during theta immediately after a transition in phase 3 (0.87 l/min), indicating a lack of reflexive load compensation. The results indicate that, because reflex load compensation is state dependent, state-related changes in airway resistance contribute to state-related changes in ventilation during sleep onset. However, this effect was slightly delayed with transitions into theta early in sleep.

Synchronization and Cardio-pulmonary feedback in Sleep Apnea

NASA Astrophysics Data System (ADS)

Xu, Limei; Ivanov, Plamen Ch.; Chen, Zhi; Hu, Kun; Paydarfar, David; Stanley, H. Eugene

2004-03-01

Findings indicate a dynamical coupling between respiratory and cardiac function. However, the nature of this nonlinear interaction remains not well understood. We investigate transient patterns in the cardio-pulmonary interaction under healthy conditions by means of cross-correlation and nonlinear synchronization techniques, and we compare how these patterns change under pathologic conditions such as obstructive sleep apnea --- a periodic cessation of breathing during sleep. We find that during apnea episodes the nonlinear features of cardio-pulmonary interaction change intermittently, and can exhibit variations characterized by different time delays in the phase synchronization between breathing and heartbeat dynamics.

Sleep Problems and Early Developmental Delay: Implications for Early Intervention Programs

ERIC Educational Resources Information Center

Bonuck, Karen; Grant, Roy

2012-01-01

Sleep disorders negatively impact behavior, cognition, and growth--the same areas targeted by early intervention. Conversely, developmental delays and disabilities may themselves precipitate sleep disorders. Young children with developmental delays experience sleep disorders at a higher rate than do typically developing children; the most common…

Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics

NASA Technical Reports Server (NTRS)

Dijk, D. J.; Duffy, J. F.

1999-01-01

The light-entrainable circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus regulates the timing and consolidation of sleep by generating a paradoxical rhythm of sleep propensity; the circadian drive for wakefulness peaks at the end of the day spent awake, ie close to the onset of melatonin secretion at 21.00-22.00 h and the circadian drive for sleep crests shortly before habitual waking-up time. With advancing age, ie after early adulthood, sleep consolidation declines, and time of awakening and the rhythms of body temperature, plasma melatonin and cortisol shift to an earlier clock hour. The variability of the phase relationship between the sleep-wake cycle and circadian rhythms increases, and in old age sleep is more susceptible to internal arousing stimuli associated with circadian misalignment. The propensity to awaken from sleep advances relative to the body temperature nadir in older people, a change that is opposite to the phase delay of awakening relative to internal circadian rhythms associated with morningness in young people. Age-related changes do not appear to be associated with a shortening of the circadian period or a reduction of the circadian drive for wake maintenance. These changes may be related to changes in the sleep process itself, such as reductions in slow-wave sleep and sleep spindles as well as a reduced strength of the circadian signal promoting sleep in the early morning hours. Putative mediators and modulators of circadian sleep regulation are discussed.

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise

PubMed Central

Kline, Christopher E.; Elliott, Jeffrey A.; Zielinski, Mark R.; Devlin, Tina M.; Moore, Teresa A.

2016-01-01

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) bright light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935

Prevalence of Circadian Misalignment and Its Association With Depressive Symptoms in Delayed Sleep Phase Disorder.

PubMed

Murray, Jade M; Sletten, Tracey L; Magee, Michelle; Gordon, Christopher; Lovato, Nicole; Bartlett, Delwyn J; Kennaway, David J; Lack, Leon C; Grunstein, Ronald R; Lockley, Steven W; Rajaratnam, Shantha M W

2017-01-01

To examine the prevalence of circadian misalignment in clinically diagnosed delayed sleep phase disorder (DSPD) and to compare mood and daytime functioning in those with and without a circadian basis for the disorder. One hundred and eighty-two DSPD patients aged 16-64 years, engaged in regular employment or school, underwent sleep-wake monitoring in the home, followed by a sleep laboratory visit for assessment of salivary dim light melatonin onset (DLMO). Based on the DLMO assessments, patients were classified into two groups: circadian DSPD, defined as DLMO occurring at or after desired bedtime (DBT), or non-circadian DSPD, defined as DLMO occurring before DBT. One hundred and three patients (57%) were classified as circadian DSPD and 79 (43%) as non-circadian DSPD. DLMO occurred 1.66 hours later in circadian DSPD compared to non-circadian DSPD (p < .001). Moderate-severe depressive symptoms (Beck Depression Inventory-II) were more prevalent in circadian DSPD (14.0%) than in non-circadian DSPD (3.8%; p < .05). Relative to non-circadian DSPD patients, circadian DSPD patients had 4.31 times increased odds of at least mild depressive symptoms (95% CI 1.75 to 10.64; p < .01). No group differences were found for daytime sleepiness or function, but DSPD symptoms were rated by clinicians to be more severe in those with circadian DSPD. Almost half of patients clinically diagnosed with DSPD did not show misalignment between the circadian pacemaker and the DBT, suggesting that the reported difficulties initiating sleep at the DBT are unlikely to be explained by the (mis)timing of the circadian rhythm of sleep propensity. Circadian misalignment in DSPD is associated with increased depressive symptoms and DSPD symptom severity. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Adaptation rate of 6-sulfatoxymelatonin and cognitive performance in offshore fleet shift workers: a field study.

PubMed

Hansen, Jakob H; Geving, Ingunn H; Reinertsen, Randi E

2010-08-01

To determine the total phase delay and adaptation rate of 6-sulfatoxymelatonin (aMT6s) on subjective and objective sleep quality and cognitive performance after 7 days of working night shifts (1800-0600 hours). The subjects studied were offshore fleet workers (N = 7). Seven days of urine samples were collected to determine the total phase delay and adaptation rate of aMT6s. Subjective and objective sleep quality was registered with sleep diaries and actigraphy on a daily basis. Cognitive performance, as measured by vigilance and reaction time, was measured with the Vienna test system on days 1 and 7. Light exposure was measured in the vessel compartments daily. The rhythm of aMT6s shifted significantly from 4.78 +/- 0.94 h on day 1 to 8.84 +/- 1.76 h on day 7. Rate of adaptation was 0.84 h per day. Subjective sleep quality showed significant time effects on four variables, but objective sleep quality did not show any significant time effects. Vigilance and reaction time improved significantly from days 1 to 7. Light exposure intensities varied between 3 and 243 lux. This field study showed that offshore fleet workers are able to adapt to the imposed regimen of 12-h night shifts. The adaptation is slower compared to other branches of the offshore industry, which most likely is due to lower light exposure. Subjective sleep quality improved to some extent, but the results were not conclusive. No significant effects were observed in the objective measures. Cognitive performance improved significantly, which was likely to be caused by the extended working hours on day 1 and an entrainment of the suprachiasmatic nuclei (SCN).

Differential sleep, sleepiness, and neurophysiology in the insomnia phenotypes of shift work disorder.

PubMed

Gumenyuk, Valentina; Belcher, Ren; Drake, Christopher L; Roth, Thomas

2015-01-01

To characterize and compare insomnia symptoms within two common phenotypes of Shift Work Disorder. Observational laboratory and field study. Hospital sleep center. 34 permanent night workers. Subjects were classified by Epworth Sleepiness Scale and Insomnia Severity Index into 3 subgroups: asymptomatic controls, alert insomniacs (AI), and sleepy insomniacs (SI). Sleep parameters were assessed by sleep diary. Circadian phase was evaluated by dim-light salivary melatonin onset (DLMO). Objective sleepiness was measured using the multiple sleep latency test (MSLT). Brain activity was measured using the N1 event-related potential (ERP). A tandem repeat in PER3 was genotyped from saliva DNA. (1) AI group showed normal MSLT scores but elevated N1 amplitudes indicating cortical hyperarousal. (2) SI group showed pathologically low MSLT scores but normal N1 amplitudes. (3) AI and SI groups were not significantly different from one another in circadian phase, while controls were significantly phase-delayed relative to both SWD groups. (4) AI showed significantly longer sleep latencies and lower sleep efficiency than controls during both nocturnal and diurnal sleep. SI significantly differed from controls in nocturnal sleep parameters, but differences during diurnal sleep periods were smaller and not statistically significant. (5) Genotype × phenotype χ² analysis showed significant differences in the PER3 VNTR: 9 of 10 shift workers reporting sleepiness in a post hoc genetic substudy were found to carry the long tandem repeat on PER3, while 4 of 14 shift workers without excessive sleepiness carried the long allele. Our results suggest that the sleepy insomnia phenotype is comprehensively explained by circadian misalignment, while the alert insomnia phenotype resembles an insomnia disorder precipitated by shift work. © 2014 Associated Professional Sleep Societies, LLC.

Long-term memory, sleep, and the spacing effect.

PubMed

Bell, Matthew C; Kawadri, Nader; Simone, Patricia M; Wiseheart, Melody

2014-01-01

Many studies have shown that memory is enhanced when study sessions are spaced apart rather than massed. This spacing effect has been shown to have a lasting benefit to long-term memory when the study phase session follows the encoding session by 24 hours. Using a spacing paradigm we examined the impact of sleep and spacing gaps on long-term declarative memory for Swahili-English word pairs by including four spacing delay gaps (massed, 12 hours same-day, 12 hours overnight, and 24 hours). Results showed that a 12-hour spacing gap that includes sleep promotes long-term memory retention similar to the 24-hour gap. The findings support the importance of sleep to the long-term benefit of the spacing effect.

Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain.

PubMed

Markwald, Rachel R; Melanson, Edward L; Smith, Mark R; Higgins, Janine; Perreault, Leigh; Eckel, Robert H; Wright, Kenneth P

2013-04-02

Insufficient sleep is associated with obesity, yet little is known about how repeated nights of insufficient sleep influence energy expenditure and balance. We studied 16 adults in a 14- to 15-d-long inpatient study and quantified effects of 5 d of insufficient sleep, equivalent to a work week, on energy expenditure and energy intake compared with adequate sleep. We found that insufficient sleep increased total daily energy expenditure by ∼5%; however, energy intake--especially at night after dinner--was in excess of energy needed to maintain energy balance. Insufficient sleep led to 0.82 ± 0.47 kg (±SD) weight gain despite changes in hunger and satiety hormones ghrelin and leptin, and peptide YY, which signaled excess energy stores. Insufficient sleep delayed circadian melatonin phase and also led to an earlier circadian phase of wake time. Sex differences showed women, not men, maintained weight during adequate sleep, whereas insufficient sleep reduced dietary restraint and led to weight gain in women. Our findings suggest that increased food intake during insufficient sleep is a physiological adaptation to provide energy needed to sustain additional wakefulness; yet when food is easily accessible, intake surpasses that needed. We also found that transitioning from an insufficient to adequate/recovery sleep schedule decreased energy intake, especially of fats and carbohydrates, and led to -0.03 ± 0.50 kg weight loss. These findings provide evidence that sleep plays a key role in energy metabolism. Importantly, they demonstrate physiological and behavioral mechanisms by which insufficient sleep may contribute to overweight and obesity.

Biological Rhythms Modelisation of Vigilance and Sleep in Microgravity State with COSINOR and Volterra's Kernels Methods

NASA Astrophysics Data System (ADS)

Gaudeua de Gerlicz, C.; Golding, J. G.; Bobola, Ph.; Moutarde, C.; Naji, S.

2008-06-01

The spaceflight under microgravity cause basically biological and physiological imbalance in human being. Lot of study has been yet release on this topic especially about sleep disturbances and on the circadian rhythms (alternation vigilance-sleep, body, temperature...). Factors like space motion sickness, noise, or excitement can cause severe sleep disturbances. For a stay of longer than four months in space, gradual increases in the planned duration of sleep were reported. [1] The average sleep in orbit was more than 1.5 hours shorter than the during control periods on earth, where sleep averaged 7.9 hours. [2] Alertness and calmness were unregistered yield clear circadian pattern of 24h but with a phase delay of 4h.The calmness showed a biphasic component (12h) mean sleep duration was 6.4 structured by 3-5 non REM/REM cycles. Modelisations of neurophysiologic mechanisms of stress and interactions between various physiological and psychological variables of rhythms have can be yet release with the COSINOR method. [3

[Sleep disorders in Internet addiction].

PubMed

Petit, Aymeric; Karila, Laurent; Estellat, Candice; Moisan, Delphine; Reynaud, Michel; D'Ortho, Marie-Pia; Lejoyeux, Michel; Levy, Fanny

2016-12-01

The relationship between sleep disorders and Internet addiction has been little work. Given the importance of these disorders, we felt it appropriate to make a synthesis of available data and to establish causality or accountability between Internet addiction and the onset of sleep disorders. A literature review was then performed. We selected scientific articles in English and French, published between 1987 and 2016 by consulting the databases Medline, Embase, PsycINFO and Google Scholar. The words used alone or in combination are as follows: addiction, dependence, Internet, behavioral addiction, sleep. A computer screen light inhibits melatonin secretion and acts as a real external desynchronizer circadian rhythm resulting in a withdrawal syndrome or syndrome sleep phase delay when the stress of social awakening is suppressed. We assume here that the specific treatment of addictive disorders have an influence on sleep disorders. Copyright © 2016. Published by Elsevier Masson SAS.

Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School

PubMed Central

Thacher, Pamela V.; Onyper, Serge V.

2016-01-01

Study Objectives: To establish whether sleep, health, mood, behavior, and academics improved after a 45-minute delay in high school start time, and whether changes persisted longitudinally. Methods: We collected data from school records and student self-report across a number of domains at baseline (May 2012) and at two follow-up time points (November 2012 and May 2013), at a public high school in upstate New York. Students enrolled during academic years (AY) 2011–2012 and 2012–2013 completed the Pittsburgh Sleep Quality Index; the DASS-21; the “Owl-Lark” Scale; the Daytime Sleepiness Index; and a brief self-report of health. Reports from school records regarding attendance, tardiness, disciplinary violations, and academic performance were collected for AY 2010–2011 through 2013–2014. Results: Students delayed but did not extend their sleep period; we found lasting improvements in tardiness and disciplinary violations after the start-time delay, but no changes to other variables. At the first follow-up, students reported 20 minutes longer sleep, driven by later rise times and stable bed times. At the second follow-up, students maintained later rise times but delayed bedtimes, returning total sleep to baseline levels. A delay in rise time, paralleling the delay in the start time that occurred, resulted in less tardiness and decreased disciplinary incidents, but larger improvements to sleep patterns may be necessary to affect health, attendance, sleepiness, and academic performance. Conclusions: Later start times improved tardiness and disciplinary issues at this school district. A delay in start time may be a necessary but not sufficient means to increase sleep time and may depend on preexisting individual differences. Commentary: A commentary on this article appears in this issue on page 267. Citation: Thacher PV, Onyper SV. Longitudinal outcomes of start time delay on sleep, behavior, and achievement in high school. SLEEP 2016;39(2):271–281. PMID:26446106

LY2033298, a positive allosteric modulator at muscarinic M₄ receptors, enhances inhibition by oxotremorine of light-induced phase shifts in hamster circadian activity rhythms.

PubMed

Gannon, Robert L; Millan, Mark J

2012-11-01

Entrainment of circadian rhythms to the light-dark cycle is essential for restorative sleep, and abnormal sleep timing is implicated in central nervous system (CNS) disorders like depression, schizophrenia, and Alzheimer's disease. Many transmitters, including acetylcholine, that exerts its actions via muscarinic receptors modulate the suprachiasmatic nucleus, the master pacemaker. Since positive allosteric modulators of muscarinic M(4) receptors are candidates for treatment of mood and cognitive deficits of CNS disorders, it is important to evaluate their circadian actions. The effects of intraperitoneally applied muscarinic agents on circadian wheel-running rhythms were measured employing hamsters, a model organism for studying activity rhythms. Systemic administration of the muscarinic receptor agonist oxotremorine (0.01-0.04 mg/kg) inhibited light-induced phase delays and advances of hamster circadian wheel-running rhythms. The M₄ positive allosteric modulator, LY2033298 (10-40 mg/kg), had no effect on light-induced phase shifts when administered alone, yet significantly enhanced (at 20 mg/kg) the inhibitory influence of oxotremorine on light-induced phase delays. In addition, the muscarinic receptor antagonist, scopolamine, which was without effect on light-induced phase shifts when administered alone (0.001-0.1 mg/kg), antagonized (at 0.1 mg/kg) the inhibitory effect of oxotremorine and LY2033298 on light-induced phase delays. These results are the first to demonstrate that systemically applied muscarinic receptor agonists modulate circadian activity rhythms, and they also reveal a specific role for M₄ receptors. It will be of importance to evaluate circadian actions of psychotropic drugs acting via M₄ receptors, since they may display beneficial properties under pathological conditions.

Circadian phase and its relationship to nighttime sleep in toddlers.

PubMed

LeBourgeois, Monique K; Carskadon, Mary A; Akacem, Lameese D; Simpkin, Charles T; Wright, Kenneth P; Achermann, Peter; Jenni, Oskar G

2013-10-01

Circadian phase and its relation to sleep are increasingly recognized as fundamental factors influencing human physiology and behavior. Dim light melatonin onset (DLMO) is a reliable marker of the timing of the circadian clock, which has been used in experimental, clinical, and descriptive studies in the past few decades. Although DLMO and its relationship to sleep have been well documented in school-aged children, adolescents, and adults, very little is known about these processes in early childhood. The purpose of this study was 1) to describe circadian phase and phase angles of entrainment in toddlers and 2) to examine associations between DLMO and actigraphic measures of children's nighttime sleep. Participants were 45 healthy toddlers aged 30 to 36 months (33.5 ± 2.2 months; 21 females). After sleeping on a parent-selected schedule for 5 days (assessed with actigraphy and diaries), children participated in an in-home DLMO assessment involving the collection of saliva samples every 30 minutes for 6 hours. Average bedtime was 2015 ± 0036 h, average sleep onset time was 2043 ± 0043 h, average midsleep time was 0143 ± 0038 h, and average wake time was 0644 ± 0042 h. Average DLMO was 1929 ± 0051 h, with a 3.5-hour range. DLMO was normally distributed; however, the distribution of the bedtime, sleep onset time, and midsleep phase angles of entrainment were skewed. On average, DLMO occurred 47.8 ± 47.6 minutes (median = 39.4 minutes) before bedtime, 74.6 ± 48.0 minutes (median = 65.4 minutes) before sleep onset time, 6.2 ± 0.7 hours (median = 6.1 hours) before midsleep time, and 11.3 ± 0.7 hours before wake time. Toddlers with later DLMOs had later bedtimes (r = 0.46), sleep onset times (r = 0.51), midsleep times (r = 0.66), and wake times (r = 0.65) (all p < 0.001). Interindividual differences in toddlers' circadian phase are large and associated with their sleep timing. The early DLMOs of toddlers indicate a maturational delay in the circadian timing system between early childhood and adolescence. These findings are a first step in describing the fundamental properties of the circadian system in toddlers and have important implications for understanding the emergence of sleep problems and the consequences of circadian misalignment in early childhood.

Shiftwork-Mediated Disruptions of Circadian Rhythms and Sleep Homeostasis Cause Serious Health Problems

PubMed Central

Duan, Pengfei

2018-01-01

Shiftwork became common during the last few decades with the growing demands of human life. Despite the social inactivity and irregularity in habits, working in continuous irregular shifts causes serious health issues including sleep disorders, psychiatric disorders, cancer, and metabolic disorders. These health problems arise due to the disruption in circadian clock system, which is associated with alterations in genetic expressions. Alteration in clock controlling genes further affects genes linked with disorders including major depression disorder, bipolar disorder, phase delay and phase advance sleep syndromes, breast cancer, and colon cancer. A diverse research work is needed focusing on broad spectrum changes caused by jet lag in brain and neuronal system. This review is an attempt to motivate the researchers to conduct advanced studies in this area to identify the risk factors and mechanisms. Its goal is extended to make the shift workers aware about the risks associated with shiftwork. PMID:29607311

Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School.

PubMed

Thacher, Pamela V; Onyper, Serge V

2016-02-01

To establish whether sleep, health, mood, behavior, and academics improved after a 45-minute delay in high school start time, and whether changes persisted longitudinally. We collected data from school records and student self-report across a number of domains at baseline (May 2012) and at two follow-up time points (November 2012 and May 2013), at a public high school in upstate New York. Students enrolled during academic years (AY) 2011-2012 and 2012-2013 completed the Pittsburgh Sleep Quality Index; the DASS-21; the "Owl-Lark" Scale; the Daytime Sleepiness Index; and a brief self-report of health. Reports from school records regarding attendance, tardiness, disciplinary violations, and academic performance were collected for AY 2010-2011 through 2013-2014. Students delayed but did not extend their sleep period; we found lasting improvements in tardiness and disciplinary violations after the start-time delay, but no changes to other variables. At the first follow-up, students reported 20 minutes longer sleep, driven by later rise times and stable bed times. At the second follow-up, students maintained later rise times but delayed bedtimes, returning total sleep to baseline levels. A delay in rise time, paralleling the delay in the start time that occurred, resulted in less tardiness and decreased disciplinary incidents, but larger improvements to sleep patterns may be necessary to affect health, attendance, sleepiness, and academic performance. Later start times improved tardiness and disciplinary issues at this school district. A delay in start time may be a necessary but not sufficient means to increase sleep time and may depend on preexisting individual differences. A commentary on this article appears in this issue on page 267. © 2016 Associated Professional Sleep Societies, LLC.

Heart Rate Dynamics and their Relation with the Cyclic Alternating Pattern of Sleep in Normal Subjects and NFLE Patients

NASA Astrophysics Data System (ADS)

González, Jose S.; Dorantes, Guadalupe; Alba, Alfonso; Méndez, Martin O.; Camacho, Sergio; Luna-Rivera, Martin; Parrino, Liborio; Riccardi, Silvia; Terzano, Mario G.; Milioli, Giulia

The aim of this work is to study the behavior of the autonomic system through variations in the heart rate (HR) during the Cyclic Alternating Pattern (CAP) which is formed by A-phases. The analysis was carried out in 10 healthy subjects and 10 patients with Nocturnal Front Lobe Epilepsy (NFLE) that underwent one whole night of polysomnographic recordings. In order to assess the relation of A-phases with the cardiovascular system, two time domain features were computed: the amplitude reduction and time delay of the minimum of the R-R intervals with respect to A-phases onset. In addition, the same process was performed over randomly chosen R-R interval segments during the NREM sleep for baseline comparisons. A non-parametric bootstrap procedure was used to test differences of the kurtosis values of two populations. The results suggest that the onset of the A-phases is correlated with a significant increase of the HR that peaks at around 4s after the A-phase onset, independently of the A-phase subtype and sleep time for both healthy subjects and NFLE patients. Furthermore, the behavior of the reduction in the R-R intervals during the A-phases was significantly different for NFLE patients with respect to control subjects.

Sleep and circadian rhythm disruption in schizophrenia†

PubMed Central

Wulff, Katharina; Dijk, Derk-Jan; Middleton, Benita; Foster, Russell G.; Joyce, Eileen M.

2012-01-01

Background Sleep disturbances comparable with insomnia occur in up to 80% of people with schizophrenia, but very little is known about the contribution of circadian coordination to these prevalent disruptions. Aims A systematic exploration of circadian time patterns in individuals with schizophrenia with recurrent sleep disruption. Method We examined the relationship between sleep-wake activity, recorded actigraphically over 6 weeks, along with ambient light exposure and simultaneous circadian clock timing, by collecting weekly 48 h profiles of a urinary metabolite of melatonin in 20 out-patients with schizophrenia and 21 healthy control individuals matched for age, gender and being unemployed. Results Significant sleep/circadian disruption occurred in all the participants with schizophrenia. Half these individuals showed severe circadian misalignment ranging from phase-advance/delay to non-24 h periods in sleep-wake and melatonin cycles, and the other half showed patterns from excessive sleep to highly irregular and fragmented sleep epochs but with normally timed melatonin production. Conclusions Severe circadian sleep/wake disruptions exist despite stability in mood, mental state and newer antipsychotic treatment. They cannot be explained by the individuals' level of everyday function. PMID:22194182

Differential Sleep, Sleepiness, and Neurophysiology in the Insomnia Phenotypes of Shift Work Disorder

PubMed Central

Gumenyuk, Valentina; Belcher, Ren; Drake, Christopher L.; Roth, Thomas

2015-01-01

Study Objectives: To characterize and compare insomnia symptoms within two common phenotypes of Shift Work Disorder. Design: Observational laboratory and field study. Setting: Hospital sleep center. Participants: 34 permanent night workers. Subjects were classified by Epworth Sleepiness Scale and Insomnia Severity Index into 3 subgroups: asymptomatic controls, alert insomniacs (AI), and sleepy insomniacs (SI). Measurements: Sleep parameters were assessed by sleep diary. Circadian phase was evaluated by dim-light salivary melatonin onset (DLMO). Objective sleepiness was measured using the multiple sleep latency test (MSLT). Brain activity was measured using the N1 event-related potential (ERP). A tandem repeat in PER3 was genotyped from saliva DNA. Results: (1) AI group showed normal MSLT scores but elevated N1 amplitudes indicating cortical hyperarousal. (2) SI group showed pathologically low MSLT scores but normal N1 amplitudes. (3) AI and SI groups were not significantly different from one another in circadian phase, while controls were significantly phase-delayed relative to both SWD groups. (4) AI showed significantly longer sleep latencies and lower sleep efficiency than controls during both nocturnal and diurnal sleep. SI significantly differed from controls in nocturnal sleep parameters, but differences during diurnal sleep periods were smaller and not statistically significant. (5) Genotype × phenotype χ2 analysis showed significant differences in the PER3 VNTR: 9 of 10 shift workers reporting sleepiness in a post hoc genetic substudy were found to carry the long tandem repeat on PER3, while 4 of 14 shift workers without excessive sleepiness carried the long allele. Conclusions: Our results suggest that the sleepy insomnia phenotype is comprehensively explained by circadian misalignment, while the alert insomnia phenotype resembles an insomnia disorder precipitated by shift work. Citation: Gumenyuk V, Belcher R, Drake CL, Roth T. Differential sleep, sleepiness, and neurophysiology in the insomnia phenotypes of shift work disorder. SLEEP 2015;38(1):119–126. PMID:25325466

A randomised controlled trial of bright light therapy and morning activity for adolescents and young adults with Delayed Sleep-Wake Phase Disorder.

PubMed

Richardson, C; Cain, N; Bartel, K; Micic, G; Maddock, B; Gradisar, M

2018-05-01

A randomised controlled trial evaluated bright light therapy and morning activity for the treatment of Delayed Sleep-Wake Phase Disorder (DSWPD) in young people. 60 adolescents and young adults (range = 13-24 years, mean = 15.9 ± 2.2 y, 63% f) diagnosed with DSWPD were randomised to receive three weeks of post-awakening Green Bright Light Therapy (∼507 nm) and Sedentary Activity (sitting, watching TV), Green Bright Light Therapy and Morning Activity (standing, playing motion-sensing videogame), Red Light Therapy (∼643 nm) and Sedentary Activity or Red Light Therapy and Morning Activity. Sleep (ie sleep onset time, wake up time, sleep onset latency, total sleep time) and daytime functioning (ie morning alertness, daytime sleepiness, fatigue, functional impairment) were measured pre-treatment, post-treatment and at one and three month follow-up. Contrary to predictions, there were no significant differences in outcomes between treatment groups; and interaction effects between treatment group and time for all outcome variables were not statistically significant. However, adolescents and young adults in morning activity conditions did not meaningfully increase their objective activity (ie movement frequency). Overall, adolescents reported significantly improved sleep timing (d = 0.30-0.46), sleep onset latency (d = 0.32) and daytime functioning (d = 0.45-0.87) post-treatment. Improvements in sleep timing (d = 0.53-0.61), sleep onset latency (d = 0.57), total sleep time (d = 0.51), and daytime functioning (d = 0.52-1.02) were maintained, or improved upon, at the three month follow-up. However, relapse of symptomology was common and 38% of adolescents and young adults requested further treatment in addition to the three weeks of light therapy. Although there is convincing evidence for the short-term efficacy of chronobiological treatments for DSWPD, long-term treatment outcomes can be improved. To address this gap in our current knowledge, avenues for future research are discussed. Australian & New Zealand Clinical Trials Registry, https://www.anzctr.org.au, ACTRN12614000308695. Copyright © 2018 Elsevier B.V. All rights reserved.

Neurofeedback in ADHD and insomnia: vigilance stabilization through sleep spindles and circadian networks.

PubMed

Arns, Martijn; Kenemans, J Leon

2014-07-01

In this review article an overview of the history and current status of neurofeedback for the treatment of ADHD and insomnia is provided. Recent insights suggest a central role of circadian phase delay, resulting in sleep onset insomnia (SOI) in a sub-group of ADHD patients. Chronobiological treatments, such as melatonin and early morning bright light, affect the suprachiasmatic nucleus. This nucleus has been shown to project to the noradrenergic locus coeruleus (LC) thereby explaining the vigilance stabilizing effects of such treatments in ADHD. It is hypothesized that both Sensori-Motor Rhythm (SMR) and Slow-Cortical Potential (SCP) neurofeedback impact on the sleep spindle circuitry resulting in increased sleep spindle density, normalization of SOI and thereby affect the noradrenergic LC, resulting in vigilance stabilization. After SOI is normalized, improvements on ADHD symptoms will occur with a delayed onset of effect. Therefore, clinical trials investigating new treatments in ADHD should include assessments at follow-up as their primary endpoint rather than assessments at outtake. Furthermore, an implication requiring further study is that neurofeedback could be stopped when SOI is normalized, which might result in fewer sessions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Delay-aware adaptive sleep mechanism for green wireless-optical broadband access networks

NASA Astrophysics Data System (ADS)

Wang, Ruyan; Liang, Alei; Wu, Dapeng; Wu, Dalei

2017-07-01

Wireless-Optical Broadband Access Network (WOBAN) is capacity-high, reliable, flexible, and ubiquitous, as it takes full advantage of the merits from both optical communication and wireless communication technologies. Similar to other access networks, the high energy consumption poses a great challenge for building up WOBANs. To shot this problem, we can make some load-light Optical Network Units (ONUs) sleep to reduce the energy consumption. Such operation, however, causes the increased packet delay. Jointly considering the energy consumption and transmission delay, we propose a delay-aware adaptive sleep mechanism. Specifically, we develop a new analytical method to evaluate the transmission delay and queuing delay over the optical part, instead of adopting M/M/1 queuing model. Meanwhile, we also analyze the access delay and queuing delay of the wireless part. Based on such developed delay models, we mathematically derive ONU's optimal sleep time. In addition, we provide numerous simulation results to show the effectiveness of the proposed mechanism.

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness

PubMed Central

Chang, Anne-Marie; Aeschbach, Daniel; Duffy, Jeanne F.; Czeisler, Charles A.

2015-01-01

In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength–enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety. PMID:25535358

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.

PubMed

Chang, Anne-Marie; Aeschbach, Daniel; Duffy, Jeanne F; Czeisler, Charles A

2015-01-27

In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength-enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety.

Sleep characteristics, chronotype and winter depression in 10-20-year-olds in northern European Russia.

PubMed

Borisenkov, Mikhail F; Petrova, Natalia B; Timonin, Vladimir D; Fradkova, Lyudmila I; Kolomeichuk, Sergey N; Kosova, Anna L; Kasyanova, Olga N

2015-06-01

The purpose of this work was to examine the relationships between geographical coordinates and the prevalence of winter depression (SADW ), and to compare the sleep characteristics and chronotype of youths with and without SADW . We conducted a cross-sectional study of self-reported sleep characteristics, chronotype and winter depression in northern European Russia. Two questionnaires, the Munich Chronotype Questionnaire (MCTQ) and the Seasonal Pattern Assessment Questionnaire (SPAQ), were administered to a total of 3435 adolescents aged 10-20 years (1517 males and 1918 females). The prevalence of SADW in the study population was 8.4% and sub-SADW 11.8%. Four variables predicted the likelihood of SADW in youths: sex [higher in females: odds ratio (OR): 1.87, P < 0.0001], age (increases with age: OR: 1.09, P < 0.001), latitude (higher in the North: OR: 1.49, P < 0.029) and position in the time zone (higher in the West: OR: 1.61, P < 0.001). Later sleeping and waking, longer sleep latencies, more severe sleep inertia, shorter total sleep times and lower sleep efficiencies were observed in both males and females with SADW . The influence of SADW on sleep characteristics was more pronounced on school days. Significant phase delays of the sleep-wake rhythm and severe social jetlag (the difference between the mid-point of sleep phase at weekends and on workdays) were observed in females with SADW , but not in males. There are significant differences in sleep characteristics and chronotype between people with SADW and no-SAD. We demonstrate that both latitude of residence and location within the time zone are significant predictors of SADW in young inhabitants of the North. © 2014 European Sleep Research Society.

Sleep Patterns in Preschool-Age Children with Autism, Developmental Delay, and Typical Development

ERIC Educational Resources Information Center

Goodlin-Jones, Beth L.; Tang, Karen; Liu, Jingyi; Anders, Thomas F.

2008-01-01

The study investigates sleep disorders by assessing the quantity and quality of sleep in preschool children with autism and comparing them with developmental delay without autism, and typical development. The results prove that sleep patterns are different in preschool children across all three categories.

Association of sleep and academic performance.

PubMed

Eliasson, Arne; Eliasson, Anders; King, Joseph; Gould, Ben; Eliasson, Arn

2002-03-01

Poor school performance by adolescent students has been attributed in part to insufficient sleep. It is recognized that a number of factors lead to diminished total sleep time and chief among these are early school start times and sleep phase delay in adolescence. Political initiatives are gaining momentum across the United States to require later school start times with the intent of increasing total sleep time and consequently improving school performance. Later school start times come with significant costs and impact other activities of families and communities. The decision to implement later school start times cannot be made lightly and deserves support of well-performed research on the impact of these changes. A study evaluating the association of academic performance and total sleep time was performed in middle school and high school students in a suburban Maryland school system. Preliminary results of this study show no correlation of total sleep time with academic performance. Before mandating costly changes in school schedules, it would be useful to perform further research to determine the effects of increasing sleep time on the behaviors of adolescent students.

Effects of evening bright light exposure on melatonin, body temperature and sleep.

PubMed

Bunnell; Treiber; Phillips; Berger

1992-03-01

Five male subjects were exposed to a single 2-h period of bright (2500 lux) or dim (<100 lux) light prior to sleep on two consecutive nights. The two conditions were repeated the following week in opposite order. Bright light significantly suppressed salivary melatonin and raised rectal temperature 0.3 degrees C (which remained elevated during the first 1.5 h of sleep), without affecting tympanic temperature. Bright light also increased REM latency, NREM period length, EEG spectral power in low frequency, 0.75-8 Hz and sigma, 12-14 Hz (sleep spindle) bandwidths during the first hour of sleep, and power of all frequency bands (0.5-32 Hz) within the first NREMP. Potentiation of EEG slow wave activity (0.5-4.0 Hz) by bright light persisted through the end of the second NREMP. The enhanced low-frequency power and delayed REM sleep after bright light exposure could represent a circadian phase-shift and/or the effect of an elevated rectal temperature, possibly mediated by the suppression of melatonin.

Sleep disorders - overview

MedlinePlus

... Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag ... disrupted sleep schedule include: Irregular sleep-wake syndrome Jet lag syndrome Shift work sleep disorder Delayed sleep ...

Circadian Melatonin and Temperature Taus in Delayed Sleep-wake Phase Disorder and Non-24-hour Sleep-wake Rhythm Disorder Patients: An Ultradian Constant Routine Study.

PubMed

Micic, Gorica; Lovato, Nicole; Gradisar, Michael; Burgess, Helen J; Ferguson, Sally A; Lack, Leon

2016-08-01

Our objectives were to investigate the period lengths (i.e., taus) of the endogenous core body temperature rhythm and melatonin rhythm in delayed sleep-wake phase disorder patients (DSWPD) and non-24-h sleep-wake rhythm disorder patients (N24SWD) compared with normally entrained individuals. Circadian rhythms were measured during an 80-h ultradian modified constant routine consisting of 80 ultrashort 1-h "days" in which participants had 20-min sleep opportunities alternating with 40 min of enforced wakefulness. We recruited a community-based sample of 26 DSWPD patients who met diagnostic criteria (17 males, 9 females; age, 21.85 ± 4.97 years) and 18 healthy controls (10 males, 8 females; age, 23.72 ± 5.10 years). Additionally, 4 full-sighted patients (3 males, 1 female; age, 25.75 ± 4.99 years) were diagnosed with N24SWD and included as a discrete study group. Ingestible core temperature capsules were used to record minute temperatures that were averaged to obtain 80 hourly data points. Salivary melatonin concentration was assessed every half-hour to determine time of dim light melatonin onset at the beginning and end of the 80-h protocol. DSWPD patients had significantly longer melatonin rhythm taus (24 h 34 min ± 17 min) than controls (24 h 22 min ± 15 min, p = 0.03, d = 0.70). These results were further supported by longer temperature rhythm taus in DSWPD patients (24 h 34 min ± 26 min) relative to controls (24 h 13 min ± 15 min, p = 0.01, d = 0.80). N24SWD patients had even longer melatonin (25 h ± 19 min) and temperature (24 h 52 min ± 17 min) taus than both DSWPD (p = 0.007, p = 0.06) and control participants (p < 0.001, p = 0.02, respectively). Between 12% and 19% of the variance in DSWPD patients' sleep timing could be explained by longer taus. This indicates that longer taus of circadian rhythms may contribute to the DSWPD patients' persistent tendency to delay, their frequent failure to respond to treatment, and their relapse following treatment. Additionally, other factors can contribute to misalignments in DSWPD and N24SWD disorders. © 2016 The Author(s).

Impact of delaying school start time on adolescent sleep, mood, and behavior.

PubMed

Owens, Judith A; Belon, Katherine; Moss, Patricia

2010-07-01

To examine the impact of a 30-minute delay in school start time on adolescents' sleep, mood, and behavior. Participants completed the online retrospective Sleep Habits Survey before and after a change in school start time. An independent high school in Rhode Island. Students (n = 201) in grades 9 through 12. Intervention Institution of a delay in school start time from 8 to 8:30 am. Sleep patterns and behavior, daytime sleepiness, mood, data from the Health Center, and absences/tardies. After the start time delay, mean school night sleep duration increased by 45 minutes, and average bedtime advanced by 18 minutes (95% confidence interval, 7-29 minutes [t(423) = 3.36; P < .001]); the percentage of students getting less than 7 hours of sleep decreased by 79.4%, and those reporting at least 8 hours of sleep increased from 16.4% to 54.7%. Students reported significantly more satisfaction with sleep and experienced improved motivation. Daytime sleepiness, fatigue, and depressed mood were all reduced. Most health-related variables, including Health Center visits for fatigue-related complaints, and class attendance also improved. A modest delay in school start time was associated with significant improvements in measures of adolescent alertness, mood, and health. The results of this study support the potential benefits of adjusting school schedules to adolescents' sleep needs, circadian rhythm, and developmental stage.

Assessing EEG sleep spindle propagation. Part 1: theory and proposed methodology.

PubMed

O'Reilly, Christian; Nielsen, Tore

2014-01-15

A convergence of studies has revealed sleep spindles to be associated with sleep-related cognitive processing and even with fundamental waking state capacities such as intelligence. However, some spindle characteristics, such as propagation direction and delay, may play a decisive role but are only infrequently investigated because of technical complexities. A new methodology for assessing sleep spindle propagation over the human scalp using noninvasive electroencephalography (EEG) is described. This approach is based on the alignment of time-frequency representations of spindle activity across recording channels. This first of a two-part series concentrates on framing theoretical considerations related to EEG spindle propagation and on detailing the methodology. A short example application is provided that illustrates the repeatability of results obtained with the new propagation measure in a sample of 32 night recordings. A more comprehensive experimental investigation is presented in part two of the series. Compared to existing methods, this approach is particularly well adapted for studying the propagation of sleep spindles because it estimates time delays rather than phase synchrony and it computes propagation properties for every individual spindle with windows adjusted to the specific spindle duration. The proposed methodology is effective in tracking the propagation of spindles across the scalp and may thus help in elucidating the temporal aspects of sleep spindle dynamics, as well as other transient EEG and MEG events. A software implementation (the Spyndle Python package) is provided as open source software. Copyright © 2013 Elsevier B.V. All rights reserved.

Sex-specific sleep patterns among university students in Lebanon: impact on depression and academic performance

PubMed Central

Kabrita, Colette S; Hajjar-Muça, Theresa A

2016-01-01

Good sleep quality and quantity are fundamental to the maintenance of normal physiological processes. Changes in sleep patterns are commonly observed among young adults and are shown to impact neurocognitive, academic, and psychological well-being. Given the scarcity of sleep information about Lebanon and acknowledging the sex differences in various sleep dimensions, we conducted a study that aimed at assessing sex differences in sleep habits among university students in Lebanon in relation to psychoacademic status. A total of 540 students (50.6% females) completed a questionnaire that inquired about sociodemographics and evaluated sleep quality and depression using the Pittsburg Sleep Quality Index (PSQI) and Center for Epidemiological Studies Depression Scale (CES-D), respectively. The mean PSQI global score (6.57±3.49) indicated poor sleep, with no significant differences between men and women. The sleep/wake rhythm was delayed on weekends for both sexes. Females exhibited earlier bedtimes and rise times and longer sleep durations on both weekdays and weekends. However, unlike males females showed a greater phase delay in wake times than bedtimes on weekends (149 minutes vs 74 minutes, respectively). In all, 70.9% of females suffered from depressive symptoms, which was a significantly higher proportion compared with 58.5% of males (P<0.01). Based on the mean cumulative self-reported grade point average (GPA), the academic performance of females was significantly better than that of males (2.8±0.61 vs 2.65±0.61, P<0.05, respectively). Depression, as scored by CES-D, in females was significantly negatively correlated with the cumulative GPA (r=−0.278, P<0.01), earlier wake time (r=−0.168, P<0.05), and average sleep duration (r=−0.221, P<0.01) on weekdays. GPA of males was significantly correlated with bedtime on weekends (r=−0.159, P<0.05). We conclude that sex differences in sleep timing, such as bedtime/rise time and nocturnal sleep duration, rather than sleep quality exist among Lebanese university students. Sex-specific sleep patterns have differential impact on psychological and academic well-being. PMID:27382345

Prevalence of causes of insomnia in primary care: a cross-sectional study

PubMed Central

Arroll, Bruce; Fernando, Antonio; Falloon, Karen; Goodyear-Smith, Felicity; Samaranayake, Chinthaka; Warman, Guy

2012-01-01

Background As a result of a research interest in primary insomnia, the prevalence of other causes of insomnia in primary care must be ascertained. No source was found in the literature. It is also essential to know the epidemiology of the common causes of a condition to make an accurate diagnosis in primary care. Aim To determine the prevalence of causes of insomnia in primary care, as part of a method of identifying patients with primary insomnia. Design and setting Cross-sectional study in three general practices in Auckland, New Zealand. Method Consecutive patients from the waiting room were asked to complete a nine-page questionnaire on possible causes of insomnia. Results In total, 1517 patients were approached and 955 completed the nine-page questionnaire (63%). Of the 41% (388) who reported difficulty with sleeping, primary insomnia occurred in 12% (45) of the population (95% confidence interval = 9% to 15%); 50% (195) had depression, 48% (185) had anxiety and 43% (165) had general (physical) health problems. Obstructive sleep apnoea occurred in 9% (34) and delayed sleep phase disorder in 2% (7). Only primary insomnia and delayed sleep phase disorder are mutually exclusive; the others can co-exist. Conclusion This is the first description of the prevalence of causes of insomnia in primary care. It is hoped that the focus on primary insomnia will result in more behavioural treatments and lower the use of hypnotics in primary care; it should also assist in the appropriate detection and treatment of other causes of insomnia in primary care. PMID:22520782

Later school start time is associated with improved sleep and daytime functioning in adolescents.

PubMed

Boergers, Julie; Gable, Christopher J; Owens, Judith A

2014-01-01

Chronic insufficient sleep is a growing concern among adolescents and is associated with a host of adverse health consequences. Early school start times may be an environmental contributor to this problem. The purpose of this study was to examine the impact of a delay in school start time on sleep patterns, sleepiness, mood, and health-related outcomes. Boarding students (n = 197, mean age = 15.6 yr) attending an independent high school completed the School Sleep Habits Survey before and after the school start time was experimentally delayed from 8:00 a.m. to 8:25 a.m. The delay in school start time was associated with a significant (29 min) increase in sleep duration on school nights. The percentage of students receiving 8 or more hours of sleep on a school night increased to more than double, from 18% to 44%. Students in 9th and 10th grade and those with lower baseline sleep amounts were more likely to report improvements in sleep duration after the schedule change. Daytime sleepiness, depressed mood, and caffeine use were all significantly reduced after the delay in school start time. Sleep duration reverted to baseline levels when the original (earlier) school start time was reinstituted. A modest (25 min) delay in school start time was associated with significant improvements in sleep duration, daytime sleepiness, mood, and caffeine use. These findings have important implications for public policy and add to research suggesting the health benefits of modifying school schedules to more closely align with adolescents' circadian rhythms and sleep needs.

Sleep patterns in high school and university students: a longitudinal study.

PubMed

Urner, Martin; Tornic, Jure; Bloch, Konrad E

2009-08-01

We performed a longitudinal study to investigate whether changes in social zeitgebers and age alter sleep patterns in students during the transition from high school to university. Actimetry was performed on 24 high-school students (mean age+/-SD: 18.4+/-0.9 yrs; 12 females) for two weeks. Recordings were repeated in the same subjects 5 yrs later when they were university students. The sleep period duration and its center, the mid-sleep time, and total sleep time were estimated by actimetry. Actigraphic total sleep time was similar when in high school and at the university on school days (6.31+/-0.47 vs. 6.45+/-0.80 h, p = ns) and longer on leisure days by 1.10+/-1.10 h (p < 0.0001 vs. school days) when in high school, but not at the university. Compared to the high school situation, the mid-sleep time was delayed when at the university on school days (03:11+/-0.6 vs. 03:55+/-0.7 h, p < 0.0001), but not on leisure days. Individual mid-sleep times on school and leisure days when in high school were significantly correlated with the corresponding values 5 yrs later when at the university (r = 0.58 and r = 0.55, p < 0.05, respectively). The large differences in total sleep time between school and leisure days when students attended high school and the delayed mid-sleep time on school days when students attended university are consistent with a circadian phase shift due to changes in class schedules, other zeitgebers, and lifestyle preferences. Age-related changes may also have occurred, although some individuality of the sleep pattern was maintained during the 5 yr study span. These findings have important implications for optimizing school and work schedules in students of different age and level of education.

The Benefit of Directed Forgetting Persists After a Daytime Nap: The Role of Spindles and Rapid Eye Movement Sleep in the Consolidation of Relevant Memories.

PubMed

Blaskovich, Borbála; Szollosi, Ágnes; Gombos, Ferenc; Racsmány, Mihály; Simor, Péter

2017-03-01

We aimed to investigate the effect of directed forgetting instruction on memory retention after a 2-hour delay involving a daytime nap or an equivalent amount of time spent awake. We examined the associations between sleep-specific oscillations and the retention of relevant and irrelevant study materials. We applied a list-method directed forgetting paradigm manipulating the perceived relevance of previously encoded lists of words. Participants were randomly assigned to either a nap or an awake group, and to a remember or a forget subgroup. The remember and the forget subgroups were both instructed to study two consecutive lists of words, although, the forget subgroup was manipulated to forget the first list and memorize only the second one. Participants were 112 healthy individuals (44 men; Mage = 21.4 years, SD = 2.4). A significant directed forgetting effect emerged after a 2-hour delay both in the awake and sleep conditions; however, the effect was more pronounced within the sleep group. The benefit of directed forgetting, that is, relatively enhanced recall of relevant words in the forget group, was evidenced only in those participants that reached rapid eye movement (REM) phase. Non-rapid eye movement (NREM) sigma power was correlated with memory performance for the relevant (second) list, and sleep spindle amplitude was associated with the retention of both lists. These associations, however, were detected only within the forget subgroup. REM duration correlated with recall performance for the relevant (second) list within the forget subgroup, and with recall performance for the first list within the remember subgroup. A directed forgetting effect persists after a 2-hour delay spent awake or asleep. Spindle-related activity and subsequent REM sleep might selectively facilitate the processing of memories that are considered to be relevant for the future. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Altered Sleep Spindles in Delayed Encephalopathy after Acute Carbon Monoxide Poisoning.

PubMed

Yoshiike, Takuya; Nishida, Masaki; Yagishita, Kazuyoshi; Nariai, Tadashi; Ishii, Kenji; Nishikawa, Toru

2016-06-15

Delayed encephalopathy (DE) affects not only the cerebral white matter and globus pallidus but also the cortex and thalamus. However, it remains unknown whether these brain lesions alter sleep along with clinical manifestations of DE. A 46-year-old man with DE underwent repetitive hyperbaric oxygen therapy. The patient was evaluated by not only neuropsychological and neuroimaging testing but polysomnography over the clinical course. Neurological symptoms improved markedly; however, profound frontal cognitive deficits continued. The polysomnography revealed prolonged absence and delayed recovery of sleep spindles across recordings. Alterations in spindle oscillations in DE could provide further insight into sleep regulatory networks. © 2016 American Academy of Sleep Medicine.

The effect of a change in sleep-wakefulness timing, bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature.

PubMed

Iskra-Golec, I; Fafrowicz, M; Marek, T; Costa, G; Folkard, S; Foret, J; Kundi, M; Smith, L

2001-12-01

Experiments consisting of baseline, bright light and physical exercise studies were carried out to compare the effect of a 9-hour delay in sleep-wakefulness timing, and the effects of bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature were examined. Each study comprised a 24-hour constant routine at the beginning followed by 3 night shifts and 24-hour constant routine at the end. Performance on tasks differing in cognitive load, mood and body temperature was measured during each constant routine and the interventions were applied during the night shifts. The 24-hour pattern of alertness and performance on the tasks with low cognitive load in post-treatment conditions followed the change in sleep-wakefulness timing while more cognitively loaded tasks tended to show a reverse trend when compared to pre-treatment conditions. There was a phase delay around 4 hours in circadian rhythms of body temperature in post-treatment conditions.

An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter.

PubMed

Corbett, R W; Middleton, B; Arendt, J

2012-09-13

Previous work has demonstrated that exposure to an hour of bright light in the morning and the evening during the Polar winter has beneficial effects on circadian phase. This study investigated the effect of a single hour of bright white morning light on circadian phase, sleep, alertness and cognitive performance. Nine individuals (eight male, one female, median age 30 years), wintering at Halley Research Station (75°S), Antarctica from 7th May until 6th August 2007, were exposed to bright white light for a fortnight from 08:30 to 09:30 h, with two fortnight control periods on either side. This sequence was performed twice, before and following Midwinter. Light exposure, sleep and alertness were assessed daily by actigraphy, sleep diaries and subjective visual analogue scales. Circadian phase (assessed by urinary 6-sulphatoxymelatonin rhythm) and cognitive performance were evaluated at the end of each fortnight. During light exposure circadian phase was advanced from 4.97 ± 0.96 decimal hours (dh) (mean ± SD) to 4.08 ± 0.68 dh (p = 0.003). Wake-up time was shifted by a similar margin from 8.45 ± 1.83 dh to 7.59 ± 0.78 dh (p < 0.001). Sleep start time was also advanced (p = 0.047) but by a lesser amount, consequently, actual sleep time was slightly reduced. There was no change in objective or subjective measures of sleep quality or subjective measures of alertness. An improvement in cognitive performance was found with both the Single Letter Cancellation Test (p < 0.001) and the Digit Symbol Substitution Test (p = 0.026) with preserved circadian variation. These beneficial effects of a single short duration light treatment may have implications not only for the Antarctic but other remote environments where access to natural light and delayed circadian phase, is problematic. These results require validation in larger studies at varying locations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The effects of sleep restriction and altered sleep timing on energy intake and energy expenditure.

PubMed

McNeil, Jessica; Doucet, Éric; Brunet, Jean-François; Hintze, Luzia Jaeger; Chaumont, Isabelle; Langlois, Émilie; Maitland, Riley; Riopel, Alexandre; Forest, Geneviève

2016-10-01

Experimental evidence suggests that sleep restriction increases energy intake (EI) and may alter energy expenditure (EE). However, it is unknown whether the timing of a sleep restriction period impacts EI and EE the following day. Hence, we examined the effects of sleep restriction with an advanced wake-time or delayed bedtime on next day EI and EE. Twelve men and 6 women (age: 23±4years, body fat: 18.8±10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-times), 50% sleep restriction with an advanced wake-time and 50% sleep restriction with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), EI (food menu), total EE and activity times (accelerometry). Carbohydrate intake was greater on day 2 in the delayed bedtime vs. control session (1386±513 vs. 1579±571kcal; P=0.03). Relative moderate-intensity physical activity (PA) time was greater in the delayed bedtime session vs. control and advanced wake-time sessions on day 1 (26.6±19.9 vs. 16.1±10.6 and 17.5±11.8%; P=0.01), whereas vigorous-intensity PA time was greater following advanced wake-time vs. delayed bedtime on day 1 (2.7±3.0 vs. 1.3±2.4%; P=0.004). Greater stage 1 sleep (β=110kcal, 95% CI for β=42 to 177kcal; P=0.004), and a trend for lower REM sleep (β=-20kcal, 95% CI for β=-41 to 2kcal; P=0.07), durations were associated with greater EI between sleep restriction sessions. These findings suggest that the timing of a sleep restriction period impacts energy balance parameters. Additional studies are needed to corroborate these findings, given the increasing prevalence of shift workers and incidences of sleep disorders and voluntary sleep restriction. Copyright © 2016 Elsevier Inc. All rights reserved.

Objective Cognitive Functioning in Self-reported Habitual Short Sleepers not Reporting Daytime Dysfunction: Examination of Impulsivity via Delay Discounting.

PubMed

Curtis, Brian J; Williams, Paula G; Anderson, Jeffrey S

2018-05-30

1) Examine performance on an objective measure of reward-related cognitive impulsivity (delay discounting) among self-reported habitual short sleepers and medium (i.e., recommended 7-9 hours) length sleepers either reporting or not reporting daytime dysfunction; 2) Inform the debate regarding what type and duration of short sleep (e.g., 21 to 24 hours of total sleep deprivation, self-reported habitual short sleep duration) meaningfully influences cognitive impulsivity; 3) Compare the predictive utility of sleep duration and perceived dysfunction to other factors previously shown to influence cognitive impulsivity via delay discounting performance (age, income, education, and fluid intelligence). We analyzed data from 1,190 adults from the Human Connectome Project database. Participants were grouped on whether they reported habitual short (≤ 6 hours) vs. medium length (7-9 hours) sleep duration and whether they perceived daytime dysfunction using the Pittsburgh Sleep Quality Index. All short sleepers exhibited increased delay discounting compared to all medium length sleepers, regardless of perceived dysfunction. Of the variables examined, self-reported sleep duration was the strongest predictor of delay discounting behavior between groups and across all 1,190 participants. Individuals who report habitual short sleep are likely to exhibit increased reward-related cognitive impulsivity regardless of perceived sleep-related daytime impairment. Therefore, there is reason to suspect that these individuals exhibit more daytime dysfunction, in the form of reward-related cognitive impulsivity, than they may assume. Current findings suggest that assessment of sleep duration over the prior month has meaningful predictive utility for human reward-related impulsivity.

Dissonance between Parent-Selected Bedtimes and Young Children's Circadian Physiology Influences Nighttime Settling Difficulties

ERIC Educational Resources Information Center

LeBourgeois, Monique K.; Wright, Kenneth P., Jr.; LeBourgeois, Hannah B.; Jenni, Oskar G.

2013-01-01

Nighttime settling difficulties (i.e., bedtime resistance, sleep-onset delay) occur in about 25% of young children and are associated with attentional, behavioral, and emotional problems. We examined whether the timing of internal (endogenous) circadian melatonin phase (i.e., dim light melatonin onset; DLMO) and its relationship with…

Adaptation of sleep and circadian rhythms to the Antarctic summer - A question of zeitgeber strength

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Macdonald, John A.; Montgomery, John C.; Paulin, Michael G.

1991-01-01

Adaptation of sleep and circadian rhythms was examined in three temperate zone dwellers arriving in Antarctica during summer. Rectal temperature, wrist activity, and heart rate were monitored continuously, sleep timing and quality noted on awakening, and mood and fatigue rated every 2 h while awake. Sleep was poorer in 2/3 subjects in Antarctica, where all subjects reported more difficulty rising. Sleep occurred at the same clock times in New Zealand and Antarctica, however, the rhythms of temperature, activity, and heart rate underwent a delay of about of 2 h. The subject with the most Antarctic experience had the least difficulty adapting to sleeping during constant daylight. The subject with the most delayed circadian rhythms had the most difficulty. The delay in the circadian system with respect to sleep and clock time is hypothesized to be due to differences in zeitgeber strength and/or zeitgeber exposure between Antarctica and New Zealand.

Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students.

PubMed

Figueiro, Mariana G; Rea, Mark S

2010-01-01

Circadian timing affects sleep onset. Delayed sleep onset can reduce sleep duration in adolescents required to awake early for a fixed school schedule. The absence of short-wavelength ("blue") morning light, which helps entrain the circadian system, can hypothetically delay sleep onset and decrease sleep duration in adolescents. The goal of this study was to investigate whether removal of short-wavelength light during the morning hours delayed the onset of melatonin in young adults. Dim light melatonin onset (DLMO) was measured in eleven 8th-grade students before and after wearing orange glasses, which removed short-wavelength light, for a five-day school week. DLMO was significantly delayed (30 minutes) after the five-day intervention, demonstrating that short-wavelength light exposure during the day can be important for advancing circadian rhythms in students. Lack of short-wavelength light in the morning has been shown to delay the circadian clock in controlled laboratory conditions. The results presented here are the first to show, outside laboratory conditions, that removal of short-wavelength light in the morning hours can delay DLMO in 8th-grade students. These field data, consistent with results from controlled laboratory studies, are directly relevant to lighting practice in schools.

Sleep Quality Changes during Overwintering at the German Antarctic Stations Neumayer II and III: The Gender Factor.

PubMed

Steinach, Mathias; Kohlberg, Eberhard; Maggioni, Martina Anna; Mendt, Stefan; Opatz, Oliver; Stahn, Alexander; Gunga, Hanns-Christian

2016-01-01

Antarctic residence holds many challenges to human physiology, like increased psycho-social tension and altered circadian rhythm, known to influence sleep. We assessed changes in sleep patterns during 13 months of overwintering at the German Stations Neumayer II and III from 2008 to 2014, with focus on gender, as many previous investigations were inconclusive regarding gender-based differences or had only included men. Time in bed, sleep time, sleep efficiency, number of arousals, sleep latency, sleep onset, sleep offset, and physical activity level were determined twice per month during seven overwintering campaigns of n = 54 participants (37 male, 17 female) using actimetry. Data were analyzed using polynomial regression and analysis of covariance for change over time with the covariates gender, inhabited station, overwintering season and influence of physical activity and local sunshine radiation. We found overall longer times in bed (p = 0.004) and sleep time (p = 0.014) for women. The covariate gender had a significant influence on time in bed (p<0.001), sleep time (p<0.001), number of arousals (p = 0.04), sleep latency (p = 0.04), and sleep onset (p<0.001). Women separately (p = 0.02), but not men (p = 0.165), showed a linear increase in number of arousals. Physical activity decreased over overwintering time for men (p = 0.003), but not for women (p = 0.174). The decline in local sunshine radiation led to a 48 minutes longer time in bed (p<0.001), 3.8% lower sleep efficiency (p<0.001), a delay of 32 minutes in sleep onset (p<0.001), a delay of 54 minutes in sleep offset (p<0.001), and 11% less daily energy expenditure (p<0.001), for all participants in reaction to the Antarctic winter's darkness-phase. Overwinterings at the Stations Neumayer II and III are associated with significant changes in sleep patterns, with dependences from overwintering time and local sunshine radiation. Gender appears to be an influence, as women showed a declining sleep quality, despite that their physical activity remained unchanged, suggesting other causes such as a higher susceptibility to psycho-social stress and changes in environmental circadian rhythm during long-term isolation in Antarctica.

Sleep Quality Changes during Overwintering at the German Antarctic Stations Neumayer II and III: The Gender Factor

PubMed Central

Steinach, Mathias; Kohlberg, Eberhard; Maggioni, Martina Anna; Mendt, Stefan; Opatz, Oliver; Stahn, Alexander; Gunga, Hanns-Christian

2016-01-01

Purpose Antarctic residence holds many challenges to human physiology, like increased psycho-social tension and altered circadian rhythm, known to influence sleep. We assessed changes in sleep patterns during 13 months of overwintering at the German Stations Neumayer II and III from 2008 to 2014, with focus on gender, as many previous investigations were inconclusive regarding gender-based differences or had only included men. Materials & Methods Time in bed, sleep time, sleep efficiency, number of arousals, sleep latency, sleep onset, sleep offset, and physical activity level were determined twice per month during seven overwintering campaigns of n = 54 participants (37 male, 17 female) using actimetry. Data were analyzed using polynomial regression and analysis of covariance for change over time with the covariates gender, inhabited station, overwintering season and influence of physical activity and local sunshine radiation. Results We found overall longer times in bed (p = 0.004) and sleep time (p = 0.014) for women. The covariate gender had a significant influence on time in bed (p<0.001), sleep time (p<0.001), number of arousals (p = 0.04), sleep latency (p = 0.04), and sleep onset (p<0.001). Women separately (p = 0.02), but not men (p = 0.165), showed a linear increase in number of arousals. Physical activity decreased over overwintering time for men (p = 0.003), but not for women (p = 0.174). The decline in local sunshine radiation led to a 48 minutes longer time in bed (p<0.001), 3.8% lower sleep efficiency (p<0.001), a delay of 32 minutes in sleep onset (p<0.001), a delay of 54 minutes in sleep offset (p<0.001), and 11% less daily energy expenditure (p<0.001), for all participants in reaction to the Antarctic winter’s darkness-phase. Conclusions Overwinterings at the Stations Neumayer II and III are associated with significant changes in sleep patterns, with dependences from overwintering time and local sunshine radiation. Gender appears to be an influence, as women showed a declining sleep quality, despite that their physical activity remained unchanged, suggesting other causes such as a higher susceptibility to psycho-social stress and changes in environmental circadian rhythm during long-term isolation in Antarctica. PMID:26918440

Sleep deprivation accelerates delay-related loss of visual short-term memories without affecting precision.

PubMed

Wee, Natalie; Asplund, Christopher L; Chee, Michael W L

2013-06-01

Visual short-term memory (VSTM) is an important measure of information processing capacity and supports many higher-order cognitive processes. We examined how sleep deprivation (SD) and maintenance duration interact to influence the number and precision of items in VSTM using an experimental design that limits the contribution of lapses at encoding. For each trial, participants attempted to maintain the location and color of three stimuli over a delay. After a retention interval of either 1 or 10 seconds, participants reported the color of the item at the cued location by selecting it on a color wheel. The probability of reporting the probed item, the precision of report, and the probability of reporting a nonprobed item were determined using a mixture-modeling analysis. Participants were studied twice in counterbalanced order, once after a night of normal sleep and once following a night of sleep deprivation. Sleep laboratory. Nineteen healthy college age volunteers (seven females) with regular sleep patterns. Approximately 24 hours of total SD. SD selectively reduced the number of integrated representations that can be retrieved after a delay, while leaving the precision of object information in the stored representations intact. Delay interacted with SD to lower the rate of successful recall. Visual short-term memory is compromised during sleep deprivation, an effect compounded by delay. However, when memories are retrieved, they tend to be intact.

School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature

PubMed Central

Chapman, Daniel P.; Croft, Janet B.

2015-01-01

BACKGROUND Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students’ academic performance, reduce engagement in risk behaviors, and improve health. METHODS This paper reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. RESULTS Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. CONCLUSIONS Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies. PMID:27040474

Sleep in Children With Autism Spectrum Disorders: How Are Measures of Parent Report and Actigraphy Related and Affected by Sleep Education?

PubMed

Veatch, Olivia J; Reynolds, Ann; Katz, Terry; Weiss, Shelly K; Loh, Alvin; Wang, Lily; Malow, Beth A

2016-01-01

Sleep disturbance is common in children with autism, resulting in a great need for effective treatments. To evaluate treatments for sleep disturbance in this population, it is critical to understand the relationship between measures of sleep captured by parent report and objective measures. The Children's Sleep Habits Questionnaire (CSHQ) and actigraphy-measured data from 80 children with autism and sleep-onset delay were evaluated. Reported problems with sleep-onset delay were concurrent with sleep duration problems in 66% of children, night wakings in 72% of children, and bedtime resistance in 66% of children; 38% of children were reported to have problems with all CSHQ insomnia domains. Actigraphy-measured sleep duration was correlated with estimates using CSHQ-reported bed and wake times.

Time delay between cardiac and brain activity during sleep transitions

NASA Astrophysics Data System (ADS)

Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

2015-04-01

Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

Vitamin B12 treatment for sleep-wake rhythm disorders.

PubMed

Okawa, M; Mishima, K; Nanami, T; Shimizu, T; Iijima, S; Hishikawa, Y; Takahashi, K

1990-02-01

Vitamin B12 (VB12) was administered to two patients suffering for many years from different sleep-wake rhythm disorders. One patient was a 15-year-old blind girl suffering from a free-running sleep-wake rhythm (hypernychthemeral syndrome) with a period of about 25 h. In spite of repeated trials to entrain her sleep-wake cycle to the environmental 24-h rhythm, her free-running rhythm persisted for about 13 years. When she was 14 years old, administration of VB12 per os was started at the daily dose of 1.5 mg t.i.d. Shortly thereafter, her sleep-wake rhythm was entrained to the environmental 24-h rhythm, and her 24-h sleep-wake rhythm was maintained while she was on the medication. Within 2 months of the withholding of VB12, her free-running sleep-wake rhythm reappeared. The VB12 level in the serum was within the normal range both before and after treatment. The other patient was a 55-year-old man suffering from delayed sleep phase syndrome since 18 years of age. After administration of VB12 at the daily doses of 1.5 mg, his sleep-wake rhythm disorder was improved. The good therapeutic effect lasted for more than 6 months while he was on the medication.

A 2-night, 3-period, crossover study of ramelteon's efficacy and safety in older adults with chronic insomnia.

PubMed

Roth, Thomas; Seiden, David; Wang-Weigand, Sherry; Zhang, Jeffrey

2007-05-01

To assess the efficacy and safety of ramelteon, a selective melatonin MT1/MT2-receptor agonist, for insomnia treatment in older adults. In a randomized, 9-week, 3-period crossover trial conducted at 17 sleep centers, older adults (N = 100) with chronic primary insomnia (37 men, 63 women; mean age [range], 70.7 [65-83] years) were administered placebo, ramelteon 4 mg, and ramelteon 8 mg in three treatment phases for two consecutive nights. Each phase was separated by 5- to 12-day washout periods. Sleep was monitored via polysomnography. Subjective sleep parameters, using a Postsleep Questionnaire, were recorded, and residual pharmacologic effects were assessed. Statistically significant reductions in latency to persistent sleep were observed with both ramelteon 4 mg and 8 mg compared to placebo (28.7 min vs. 38.4 min, p < 0.001; 30.8 min vs. 38.4 min, p = 0.005, respectively). Total sleep time (p = 0.036 and p = 0.007, respectively) and sleep efficiency (p = 0.037 and p = 0.007, respectively) were also significantly improved with ramelteon 4 mg and 8 mg compared to placebo. Statistically significant reductions in subjective sleep latency on a Postsleep Questionnaire were reported with ramelteon 4 mg versus placebo (p = 0.037), but not ramelteon 8 mg (p = 0.120); no significant differences on other subjective sleep assessments were reported. A lack of power limits interpretation of self-reported sleep parameters. Incidences of adverse events considered treatment related were placebo (7%), ramelteon 4 mg (11%), and ramelteon 8 mg (5%). No residual pharmacologic effects were observed via Digit Symbol Substitution Test, memory recall tests (immediate and delayed), visual analog scales (feelings and mood), and Postsleep Questionnaire (level of alertness and ability to concentrate). In older adults with chronic primary insomnia, ramelteon produced significant reductions in latency to persistent sleep and increases in total sleep time and sleep efficacy, and showed no evidence of adverse next-day psychomotor or cognitive effects.

Genetic variation in melatonin pathway enzymes in children with autism spectrum disorder and comorbid sleep onset delay.

PubMed

Veatch, Olivia J; Pendergast, Julie S; Allen, Melissa J; Leu, Roberta M; Johnson, Carl Hirschie; Elsea, Sarah H; Malow, Beth A

2015-01-01

Sleep disruption is common in individuals with autism spectrum disorder (ASD). Genes whose products regulate endogenous melatonin modify sleep patterns and have been implicated in ASD. Genetic factors likely contribute to comorbid expression of sleep disorders in ASD. We studied a clinically unique ASD subgroup, consisting solely of children with comorbid expression of sleep onset delay. We evaluated variation in two melatonin pathway genes, acetylserotonin O-methyltransferase (ASMT) and cytochrome P450 1A2 (CYP1A2). We observed higher frequencies than currently reported (p < 0.04) for variants evidenced to decrease ASMT expression and related to decreased CYP1A2 enzyme activity (p ≤ 0.0007). We detected a relationship between genotypes in ASMT and CYP1A2 (r(2) = 0.63). Our results indicate that expression of sleep onset delay relates to melatonin pathway genes.

Descartes and His Peculiar Sleep Pattern.

PubMed

Damjanovic, Aleksandar; Milovanovic, Srdjan D; Trajanovic, Nikola N

2015-01-01

Rene Descartes (1596-1650) was a mathematician, philosopher, and scholar, whose work set a foundation for modern science. Among other interests, he focused on locating the "core and the seat of the soul" and concluded that the pineal gland was such a structure. Recent scientific findings validate Descartes' deep interest in pineal gland, appreciating its role as part of the circadian rhythm system. On the other hand, the biographical information suggests that Descartes had an aberration of the circadian rhythm (delayed sleep phase). Coincidentally, this meant that one of the most important things in his private life and one of the most significant areas of his research intersected in an overlooked way.

Short-term total sleep deprivation alters delay-conditioned memory in the rat.

PubMed

Tripathi, Shweta; Jha, Sushil K

2016-06-01

Short-term sleep deprivation soon after training may impair memory consolidation. Also, a particular sleep stage or its components increase after learning some tasks, such as negative and positive reinforcement tasks, avoidance tasks, and spatial learning tasks, and so forth. It suggests that discrete memory types may require specific sleep stage or its components for their optimal processing. The classical conditioning paradigms are widely used to study learning and memory but the role of sleep in a complex conditioned learning is unclear. Here, we have investigated the effects of short-term sleep deprivation on the consolidation of delay-conditioned memory and the changes in sleep architecture after conditioning. Rats were trained for the delay-conditioned task (for conditioning, house-light [conditioned stimulus] was paired with fruit juice [unconditioned stimulus]). Animals were divided into 3 groups: (a) sleep deprived (SD); (b) nonsleep deprived (NSD); and (c) stress control (SC) groups. Two-way ANOVA revealed a significant interaction between groups and days (training and testing) during the conditioned stimulus-unconditioned stimulus presentation. Further, Tukey post hoc comparison revealed that the NSD and SC animals exhibited significant increase in performances during testing. The SD animals, however, performed significantly less during testing. Further, we observed that wakefulness and NREM sleep did not change after training and testing. Interestingly, REM sleep increased significantly on both days compared to baseline more specifically during the initial 4-hr time window after conditioning. Our results suggest that the consolidation of delay-conditioned memory is sleep-dependent and requires augmented REM sleep during an explicit time window soon after training. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Older poor-sleeping women display a smaller evening increase in melatonin secretion and lower values of melatonin and core body temperature than good sleepers.

PubMed

Olbrich, Denise; Dittmar, Manuela

2011-10-01

Melatonin concentration and core body temperature (CBT) follow endogenous circadian biological rhythms. In the evening, melatonin level increases and CBT decreases. These changes are involved in the regulation of the sleep-wake cycle. Therefore, the authors hypothesized that age-related changes in these rhythms affect sleep quality in older people. In a cross-sectional study design, 11 older poor-sleeping women (aged 62-72 yrs) and 9 older good-sleeping women (60-82 yrs) were compared with 10 younger good-sleeping women (23-28 yrs). The older groups were matched by age and body mass index. Sleep quality was assessed by the Pittsburgh Sleep Quality Index questionnaire. As an indicator of CBT, oral temperature was measured at 1-h intervals from 17:00 to 24:00 h. At the same time points, saliva samples were collected for determining melatonin levels by enzyme-linked immunosorbent assay (ELISA). The dim light melatonin onset (DLMO), characterizing the onset of melatonin production, was calculated. Evening changes in melatonin and CBT levels were tested by the Friedman test. Group comparisons were performed with independent samples tests. Predictors of sleep-onset latency (SOL) were assessed by regression analysis. Results show that the mean CBT decreased in the evening from 17:00 to 24:00 h in both young women (from 36.57°C to 36.25°C, p < .001) and older women (from 36.58°C to 35.88°C, p < .001), being lowest in the older poor sleepers (p < .05). During the same time period, mean melatonin levels increased in young women (from 16.2 to 54.1 pg/mL, p < .001) and older women (from 10.0 to 23.5 pg/mL, p < .001), being lowest among the older poor sleepers (from 20:00 to 24:00 h, p < .05 vs. young women). Older poor sleepers also showed a smaller increase in melatonin level from 17:00 to 24:00 h than older good sleepers (mean ± SD: 7.0 ± 9.63 pg/mL vs. 15.6 ± 24.1 pg/mL, p = .013). Accordingly, the DLMO occurred at similar times in young (20:10 h) and older (19:57 h) good-sleeping women, but was delayed ∼50 min in older poor-sleeping women (20:47 h). Older poor sleepers showed a shorter phase angle between DLMO and sleep onset, but a longer phase angle between CBT peak and sleep onset than young good sleepers, whereas older good sleepers had intermediate phase angles (insignificant). Regression analysis showed that the DLMO was a significant predictor of SOL in the older women (R(2) = 0.64, p < .001), but not in the younger women. This indicates that melatonin production started later in those older women who needed more time to fall asleep. In conclusion, changes in melatonin level and CBT were intact in older poor sleepers in that evening melatonin increased and CBT decreased. However, poor sleepers showed a weaker evening increase in melatonin level, and their DLMO was delayed compared with good sleepers, suggesting that it is not primarily the absolute level of endogenous melatonin, but rather the timing of the circadian rhythm in evening melatonin secretion that might be related to disturbances in the sleep-wake cycle in older people.

Parent-Based Sleep Education for Children with Autism Spectrum Disorders

PubMed Central

Malow, Beth A.; Adkins, Karen W.; Reynolds, Ann; Weiss, Shelly K.; Loh, Alvin; Fawkes, Diane; Katz, Terry; Goldman, Suzanne E.; Madduri, Niru; Hundley, Rachel; Clemons, Traci

2013-01-01

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and one month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group vs. individualized education did not affect outcome. PMID:23754339

Parent-based sleep education for children with autism spectrum disorders.

PubMed

Malow, Beth A; Adkins, Karen W; Reynolds, Ann; Weiss, Shelly K; Loh, Alvin; Fawkes, Diane; Katz, Terry; Goldman, Suzanne E; Madduri, Niru; Hundley, Rachel; Clemons, Traci

2014-01-01

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and 1 month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group versus individualized education did not affect outcome.

Sleep Disorders in Adult Sickle Cell Patients

PubMed Central

Sharma, Sunil; Efird, Jimmy T.; Knupp, Charles; Kadali, Renuka; Liles, Darla; Shiue, Kristin; Boettger, Peter; Quan, Stuart F.

2015-01-01

Study Objectives: While sleep apnea has been studied in children with sickle cell disease (SCD), little is known about sleep disorders in adult sickle cell patients. The objective of this study was to evaluate sleep disordered breathing and its polysomnographic characteristics in adult patients with sickle cell disease. Methods: The analysis cohort included 32 consecutive adult SCD patients who underwent a comprehensive sleep evaluation and overnight polysomnography in an accredited sleep center after reporting symptoms suggesting disordered sleep or an Epworth Sleepiness Scale score ≥ 10. Epworth score, sleep parameters, comorbid conditions, and narcotic use were reviewed and compared in patients with and without sleep disordered breathing. SCD complication rates in the two groups also were compared. Results: In adult SCD patients who underwent overnight polysomnography, we report a high prevalence (44%) of sleep disordered breathing. Disease severity was mild to moderate (mean apnea-hypopnea index = 17/h (95% CI: 10–24/h). Concomitant sleep disorders, including insomnia complaints (57%) and delayed sleep-phase syndrome (57%), also were common in this population. In this limited cohort, we did not find increased SCD complications associated with sleep disordered breathing in adult patients with sickle cell disease. Conclusions: A high burden of sleep disordered breathing and other sleep-related complaints were identified in the adult sickle cell population. Our results provide important information on this unique population. Citation: Sharma S, Efird JT, Knupp C, Kadali R, Liles D, Shiue K, Boettger P, Quan SF. Sleep disorders in adult sickle cell patients. J Clin Sleep Med 2015;11(3):219–223. PMID:25515282

Sleep in Children with Autism Spectrum Disorders: How are Measures of Parent Report and Actigraphy Related and Affected by Sleep Education?

PubMed Central

Veatch, Olivia J.; Reynolds, Ann; Katz, Terry; Weiss, Shelly K.; Loh, Alvin; Wang, Lily; Malow, Beth A.

2015-01-01

Sleep disturbance is common in children with autism, resulting in a great need for effective treatments. To evaluate treatments for sleep disturbance in this population, it is critical to understand the relationship between measures of sleep captured by parent report and objective measures. The Children’s Sleep Habits Questionnaire (CSHQ) and actigraphy-measured data from 80 children with autism and sleep onset delay were evaluated. Reported problems with sleep onset delay were concurrent with sleep duration problems in 66% of children, night wakings in 72% of children, and bedtime resistance in 66% of children; 38% of children were reported to have problems with all CSHQ insomnia domains. Actigraphy-measured sleep duration was correlated with estimates using CSHQ-reported bed and wake times. PMID:26619899

Sleep and meal-time misalignment alters functional connectivity: a pilot resting-state study.

PubMed

Yoncheva, Y N; Castellanos, F X; Pizinger, T; Kovtun, K; St-Onge, M-P

2016-11-01

Delayed sleep and meal times promote metabolic dysregulation and obesity. Altered coordination of sleeping and eating times may impact food-reward valuation and interoception in the brain, yet the independent and collective contributions of sleep and meal times are unknown. This randomized, in-patient crossover study experimentally manipulates sleep and meal times while preserving sleep duration (7.05±0.44 h for 5 nights). Resting-state functional magnetic resonance imaging scans (2 × 5-minute runs) were obtained for four participants (three males; 25.3±4.6 years), each completing all study phases (normal sleep/normal meal; late sleep/normal meal; normal sleep/late meal; and late sleep/late meal). Normal mealtimes were 1, 5, 11 and 12.5 h after awakening; late mealtimes were 4.5, 8.5, 14.5 and 16 h after awakening. Seed-based resting-state functional connectivity (RSFC) was computed for a priori regions-of-interest (seeds) and contrasted across conditions. Statistically significant (P<0.05, whole-brain corrected) regionally specific effects were found for multiple seeds. The strongest effects were linked to the amygdala: increased RSFC for late versus normal mealtimes (equivalent to skipping breakfast). A main effect of sleep and interaction with meal time were also observed. Preliminary findings support the feasibility of examining the effects of sleep and meal-time misalignment, independent of sleep duration, on RSFC in regions relevant to food reward and interoception.

Getting a Good Night's Sleep in Adolescence: Do Strategies for Coping With Stress Matter?

PubMed

Matthews, Karen A; Hall, Martica H; Cousins, Jennifer; Lee, Laisze

2016-01-01

Getting a good night's sleep is challenging for adolescents because of early school start times and adolescents' substantial social and physical changes. We tested whether key indices of sleep health are associated with usual styles of coping with stress and interpersonal conflict in healthy black and white adolescents. Two hundred forty-two (57% female, 56% black) high school students completed daily sleep diaries, questionnaires, and actigraphy across a school week. Linear regression models tested associations, independent of race, gender, and other covariates. Students who reported using disengagement coping exhibited poor sleep health. They had shorter sleep duration, more fragmented sleep, delayed sleep, and increased daytime sleepiness. Unexpectedly, positive engagement coping was related to daytime sleepiness and delayed sleep, although not in models that included disengagement coping. Coping strategies may be an important influence on adolescent sleep. Future research should evaluate the antecedent-consequent relationships among coping, sleep, and stress.

Delayed School Start Times and Adolescent Sleep: A Systematic Review of the Experimental Evidence

PubMed Central

Minges, Karl E.; Redeker, Nancy S.

2016-01-01

Summary Many schools have instituted later morning start times to improve sleep, academic, and other outcomes in response to the mismatch between youth circadian rhythms and early morning start times. However, there has been no systematic synthesis of the evidence on the effects of this practice. To examine the impact of delayed school start time on students’ sleep, health, and academic outcomes, electronic databases were systematically searched and data were extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six studies satisfied selection criteria and used pre-post, no control (n=3), randomized controlled trial (n=2), and quasi-experimental (n=1) designs. School start times were delayed 25 to 60 minutes, and correspondingly, total sleep time increased from 25 to 77 minutes per weeknight. Some studies revealed reduced daytime sleepiness, depression, caffeine use, tardiness to class, and trouble staying awake. Overall, the evidence supports recent non-experimental study findings and calls for policy that advocates for delayed school start time to improve sleep. This presents a potential long-term solution to chronic sleep restriction during adolescence. However, there is a need for rigorous randomized study designs and reporting of consistent outcomes, including objective sleep measures and consistent measures of health and academic performance. PMID:26545246

School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: A Review of the Literature.

PubMed

Wheaton, Anne G; Chapman, Daniel P; Croft, Janet B

2016-05-01

Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students' academic performance, reduce engagement in risk behaviors, and improve health. This article reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Sleep Patterns in Chinese Preschool Children: A Population-Based Study.

PubMed

Wu, Ran; Wang, Guang-Hai; Zhu, Hong; Jiang, Fan; Jiang, Chun-Lei

2018-04-15

This study aimed to (1) provide data on normal sleep patterns in Chinese preschool children, (2) identify cross-cultural differences of sleep patterns among children from China and other countries, (3) estimate the prevalence of sleep duration not meeting the optimal amount, and (4) characterize delayed weekend sleep pattern. A population-based sample of 1,610 children aged 3-6 years was recruited from 10 cities across China. Parents completed questions about their child's sleep patterns adapted from the Children's Sleep Habits Questionnaire (CSHQ). The mean bedtime was 9:31 PM, wake time was 7:27 AM, nighttime sleep duration was 9 hours 30 minutes, daytime sleep duration was 1 hour 31 minutes, and total sleep duration was 11 hours 2 minutes. The children had a shorter nighttime sleep duration but longer daytime naps, resulting in no differences in total sleep duration compared with counterparts predominantly in the west. Of the children, 85.3% met the recommended amount of sleep of 10 to 13 hours, and 10.8% slept fewer than 10 hours. The prevalence of sleep less than 10 hours was higher in older children and children from eastern China. Children went to bed and woke up more than 30 minutes later on weekends than weekdays, accounting for 40.1% and 50%, respectively. Children in western China showed longer delay than children in eastern China ( P < .05). Age- and region-specific variability of sleep patterns are reported as well as insufficient sleep and delayed weekend sleep pattern in Chinese preschool children. The cross-cultural difference of sleep patterns was in temporal placement rather than sleep duration. © 2018 American Academy of Sleep Medicine.

Practice parameters for the clinical evaluation and treatment of circadian rhythm sleep disorders. An American Academy of Sleep Medicine report.

PubMed

Morgenthaler, Timothy I; Lee-Chiong, Teofilo; Alessi, Cathy; Friedman, Leah; Aurora, R Nisha; Boehlecke, Brian; Brown, Terry; Chesson, Andrew L; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J; Zak, Rochelle

2007-11-01

The expanding science of circadian rhythm biology and a growing literature in human clinical research on circadian rhythm sleep disorders (CRSDs) prompted the American Academy of Sleep Medicine (AASM) to convene a task force of experts to write a review of this important topic. Due to the extensive nature of the disorders covered, the review was written in two sections. The first review paper, in addition to providing a general introduction to circadian biology, addresses "exogenous" circadian rhythm sleep disorders, including shift work disorder (SWD) and jet lag disorder (JLD). The second review paper addresses the "endogenous" circadian rhythm sleep disorders, including advanced sleep phase disorder (ASPD), delayed sleep phase disorder (DSPD), irregular sleep-wake rhythm (ISWR), and the non-24-hour sleep-wake syndrome (nonentrained type) or free-running disorder (FRD). These practice parameters were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the AASM to present recommendations for the assessment and treatment of CRSDs based on the two accompanying comprehensive reviews. The main diagnostic tools considered include sleep logs, actigraphy, the Morningness-Eveningness Questionnaire (MEQ), circadian phase markers, and polysomnography. Use of a sleep log or diary is indicated in the assessment of patients with a suspected circadian rhythm sleep disorder (Guideline). Actigraphy is indicated to assist in evaluation of patients suspected of circadian rhythm disorders (strength of recommendation varies from "Option" to "Guideline," depending on the suspected CRSD). Polysomnography is not routinely indicated for the diagnosis of CRSDs, but may be indicated to rule out another primary sleep disorder (Standard). There is insufficient evidence to justify the use of MEQ for the routine clinical evaluation of CRSDs (Option). Circadian phase markers are useful to determine circadian phase and confirm the diagnosis of FRD in sighted and unsighted patients but there is insufficient evidence to recommend their routine use in the diagnosis of SWD, JLD, ASPD, DSPD, or ISWR (Option). Additionally, actigraphy is useful as an outcome measure in evaluating the response to treatment for CRSDs (Guideline). A range of therapeutic interventions were considered including planned sleep schedules, timed light exposure, timed melatonin doses, hypnotics, stimulants, and alerting agents. Planned or prescribed sleep schedules are indicated in SWD (Standard) and in JLD, DSPD, ASPD, ISWR (excluding elderly-demented/nursing home residents), and FRD (Option). Specifically dosed and timed light exposure is indicated for each of the circadian disorders with variable success (Option). Timed melatonin administration is indicated for JLD (Standard); SWD, DSPD, and FRD in unsighted persons (Guideline); and for ASPD, FRD in sighted individuals, and for ISWR in children with moderate to severe psychomotor retardation (Option). Hypnotic medications may be indicated to promote or improve daytime sleep among night shift workers (Guideline) and to treat jet lag-induced insomnia (Option). Stimulants may be indicated to improve alertness in JLD and SWD (Option) but may have risks that must be weighed prior to use. Modafinil may be indicated to improve alertness during the night shift for patients with SWD (Guideline).

The impact of sleep on true and false memory across long delays.

PubMed

Pardilla-Delgado, Enmanuelle; Payne, Jessica D

2017-01-01

While the influence of sleep on memory has a long history, sleep's role in the formation of false memories is less clear. Moreover, virtually nothing is known about the development of false memories beyond delays of about 12h. Here, for the first time, we assess post-sleep development of true and false memories across longer delay intervals of 24 and 48h. Although technically a false memory, remembering information that is related to the theme, or gist, of an experience can be considered an adaptive process. Some evidence suggests that sleep, compared to a wake period, increases both true and gist-based false memories in the Deese-Roediger-McDermott (DRM) task, but not all studies have returned this result, and most studies cannot rule out the possibility that sleep is merely protecting the information from interference, as opposed to actively aiding its consolidation. Here, to equate amount of time spent awake and asleep across groups, we assess how the positioning of sleep relative to memory encoding impacts retention across longer delays of 24 and 48h. Participants encoded 16 DRM lists in the morning (WAKE 1st Groups) or evening (SLEEP 1st Groups), and were tested either 24 or 48h later at the same time of day. Results demonstrate that true memory is better when participants sleep soon after learning. Sleeping first also increased false memory, but only in low performers. Importantly, and similar to previous studies, we found a negative correlation between slow-wave sleep (SWS) and false memory, suggesting that SWS may be detrimental for semantic/gist processing. Copyright © 2016 Elsevier Inc. All rights reserved.

A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho

Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.

Partial sleep deprivation impacts impulsive action but not impulsive decision-making.

PubMed

Demos, K E; Hart, C N; Sweet, L H; Mailloux, K A; Trautvetter, J; Williams, S E; Wing, R R; McCaffery, J M

2016-10-01

Sleep deprivation may lead to increased impulsivity, however, previous literature has focused on examining effects of total sleep deprivation (TSD) rather than the more common condition, partial sleep deprivation (PSD) or 'short sleep'. Moreover, it has been unclear whether PSD impacts impulse-related cognitive processes, and specifically if it differentially affects impulsive action versus impulsive decision-making. We sought to determine if short compared to long sleep (6 vs. 9h/night) impacts impulsive action via behavioral inhibition (Go/No-Go), and/or impulsive decision-making processes of risk taking (Balloon Analogue Risk Task [BART]) and preferences for immediate over delayed rewards (Delay Discounting). In a within-subject design, 34 participants (71% female, mean age=37.0years, SD=10.54) were assigned to four consecutive nights of 6h/night (short sleep) and 9h/night (long sleep) in their own home in random counterbalanced order. Sleep was measured via wrist-worn actigraphs to confirm adherence to the sleep schedules (mean short sleep=5.9h, SD=0.3; mean long sleep=8.6h, SD=0.3, p<0.001). The Go/No-Go, BART, and Delay Discounting tasks were completed following both sleep conditions. Participants had more inhibition errors on the Go/No-Go task after short (mean false alarms=19.79%, SD=14.51) versus long sleep (mean=15.97%, SD=9.51, p=0.039). This effect was strongest in participants reporting longer habitual time in bed (p=0.04). There were no differences in performance following long- versus short-sleep for either delay discounting or the BART (p's>0.4). Overall, these results indicate that four days of PSD diminishes behavioral inhibition abilities, but may not alter impulsive decision-making. These findings contribute to the emerging understanding of how partial sleep deprivation, currently an epidemic, impacts cognitive ability. Future research should continue to explore the connection between PSD and cognitive functions, and ways to minimize the occurrence and negative consequences of short sleep. Copyright © 2016 Elsevier Inc. All rights reserved.

Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miletich, R.S.

The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period,more » phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.« less

Performance analysis of TCP traffic and its influence on ONU's energy saving in energy efficient TDM-PON

NASA Astrophysics Data System (ADS)

Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; Lee, Joohyung; Uddin, Mohammad Rakib; Lee, Gyu Myoung; Choi, Jun Kyun

2015-12-01

The majority of the traffic over the Internet is TCP based, which is very sensitive to packet loss and delay. Existing research efforts in TDM-Passive Optical Networks (TDM-PONs) mostly evaluate energy saving and traffic delay performances under different energy saving solutions. However, to the best of our knowledge, how energy saving mechanisms could affect TCP traffic performance in TDM-PONs has hardly been studied. In this paper, by means of our state-of-art OPNET Modular based TDM-PON simulator, we evaluate TCP traffic delay, throughput, and Optical Network Unit (ONU) energy consumption performances in a TDM-PON where energy saving mechanisms are employed in ONUs. Here, we study the performances under commonly used energy saving mechanisms defined in standards for TDM-PONs: cyclic sleep and doze mode. In cyclic sleep mode, we evaluate the performances under two well-known sleep interval length deciding algorithms (i.e. fixed sleep interval (FSI) and exponential sleep interval deciding (ESID)) that an OLT uses to decide sleep interval lengths for an ONU. Findings in this paper put forward the strong relationship among TCP traffic delay, throughput and ONU energy consumption under different sleep interval lengths. Moreover, we reveal that under high TCP traffic, both FSI and ESID will end up showing similar delay, energy and throughput performance. Our findings also show that doze mode can offer better TCP throughput and delay performance at the price of consuming more energy than cyclic sleep mode. In addition, our results provide a glimpse on understanding at what point doze mode becomes futile in improving energy saving of an ONU under TCP traffic. Furthermore, in this paper, we highlight important research issues that should be studied in future research to maximize energy saving in TDM-PONs while meeting traffic Quality of Service requirements.

A novel smart lighting clinical testbed.

PubMed

Gleason, Joseph D; Oishi, Meeko; Simkulet, Michelle; Tuzikas, Arunas; Brown, Lee K; Brueck, S R J; Karlicek, Robert F

2017-07-01

A real-time, feedback-capable, variable spectrum lighting system was recently installed at the University of New Mexico Hospital to facilitate biomedical research on the health impacts of lighting. The system consists of variable spectrum troffers, color sensors, occupancy sensors, and computing and communication infrastructure, and is the only such clinical facility in the US. The clinical environment posed special challenges for installation as well as for ongoing maintenance and operations. Pilot studies are currently underway to evaluate the effectiveness of the system to regulate circadian phase in subjects with delayed sleep-wake phase disorder.

Obstructive sleep apnea syndrome and nocturnal epilepsy with tonic seizures.

PubMed

Bialasiewicz, Piotr; Nowak, Dariusz

2009-12-01

Some ambiguous symptoms may delay or lead to an erroneous diagnosis. We present a case of pure sleep, generalized tonic seizures in a patient with concomitant sleep apnea syndrome. The prolonged apneic periods with tonic muscle contracture lasting minutes and occurring exclusively at night with ensuing confusional state posed diagnostic difficulties because of the negative EEG at the beginning of the workup and the absence of other epilepsy symptoms (i.e. clonic phase, tongue biting, enuresis, seizures while awake). Numerous apneas on polysomnography led to the diagnosis of sleep apnea syndrome. No effect of continuous positive airways pressure (CPAP) treatment on frequency of the nocturnal tonic epileptic fits and the repetitive character of the clinical presentation combined with the typical pathologic changes on subsequent EEGs permitted to suggest the epileptic nature of the paroxysmal events. Episodes stopped following administration of clonazepam. However, spontaneous, coincidental remission of seizures cannot be excluded since the patient remained seizure free even after discontinuation of the drug.

Partial sleep deprivation impacts impulsive action but not impulsive decision-making

PubMed Central

Demos, K.E.; Hart, C.N.; Sweet, LH.; Mailloux, K.A.; Trautvetter, J.; Williams, S.E.; Wing, R.R.; McCaffery, J.M.

2017-01-01

Sleep deprivation may lead to increased impulsivity, however, previous literature has focused on examining effects of total sleep deprivation (TSD) rather than the more common condition, partial sleep deprivation (PSD) or ‘short sleep’. Moreover, it has been unclear whether PSD impacts impulse-related cognitive processes, and specifically if it differentially affects impulsive action versus impulsive decision-making. We sought to determine if short compared to long sleep (6 vs. 9 h/night) impacts impulsive action via behavioral inhibition (Go/No-Go), and/or impulsive decision-making processes of risk taking (Balloon Analogue Risk Task [BART]) and preferences for immediate over delayed rewards (Delay Discounting). In a within-subject design, 34 participants (71% female, mean age = 37.0 years, SD = 10.54) were assigned to four consecutive nights of 6 h/night (short sleep) and 9 h/night (long sleep) in their own home in random counterbalanced order. Sleep was measured via wrist-worn actigraphs to confirm adherence to the sleep schedules (mean short sleep = 5.9 h, SD = 0.3; mean long sleep = 8.6 h, SD = 0.3, p < 0.001). The Go/No-Go, BART, and Delay Discounting tasks were completed following both sleep conditions. Participants had more inhibition errors on the Go/No-Go task after short (mean false alarms = 19.79%, SD = 14.51) versus long sleep (mean = 15.97%, SD = 9.51, p = 0.039). This effect was strongest in participants reporting longer habitual time in bed (p = 0.04). There were no differences in performance following long- versus short-sleep for either delay discounting or the BART (p’s > 0.4). Overall, these results indicate that four days of PSD diminishes behavioral inhibition abilities, but may not alter impulsive decision-making. These findings contribute to the emerging understanding of how partial sleep deprivation, currently an epidemic, impacts cognitive ability. Future research should continue to explore the connection between PSD and cognitive functions, and ways to minimize the occurrence and negative consequences of short sleep. PMID:27267950

Light treatment for NASA shiftworkers.

PubMed

Stewart, K T; Hayes, B C; Eastman, C I

1995-04-01

Intense artificial light can phase-shift circadian rhythms and improve performance, sleep, and well-being during shiftwork simulations. In real shiftworkers, however, exposure to sunlight and other time cues may decrease the efficacy of light treatment, and occupational and family responsibilities may make it impractical. With these considerations in mind, we designed and tested light-treatment protocols for NASA personnel who worked on shifted schedules during two Space Shuttle missions. During the prelaunch week, treatment subjects self-administered light of approximately 10,000 lux at times of day that phase-delay circadian rhythms. Treatment continued during the missions and for several days afterward. No treatment was administered to subjects in the control group. Treatment subjects reported better sleep, performance, and physical and emotional well-being than control subjects and rated the treatment as highly effective for promoting adjustment to their work schedules. Light treatment is both feasible and beneficial for NASA personnel who must work on shifted schedules during Space Shuttle missions.

Hericium erinaceus extracts alter behavioral rhythm in mice.

PubMed

Furuta, Shoko; Kuwahara, Rika; Hiraki, Eri; Ohnuki, Koichiro; Yasuo, Shinobu; Shimizu, Kuniyoshi

2016-01-01

Hericium erinaceus (HE), an edible mushroom, has been used as a herbal medicine in several Asian countries since ancient times. HE has potential as a medicine for the treatment and prevention of dementia, a disorder closely linked with circadian rhythm. This study investigated the effects of the intake of HE extracts on behavioral rhythm, photosensitivity of the circadian clock, and clock gene mRNA expression in the suprachiasmatic nucleus (SCN), a central clock, in mice. Although the HE ethanol extract only affected the offset time of activity, the HE water extract advanced the sleep-wake cycle without affecting the free-running period, photosensitivity, or the clock gene mRNA expression in SCN. In addition, both extracts decreased wakefulness around end of active phase. The findings of the present study suggest that HE may serve as a functional food in the prevention and treatment of Alzheimer's disease and delayed sleep phase syndrome.

Circadian rhythm phase shifts and endogenous free-running circadian period differ between African-Americans and European-Americans.

PubMed

Eastman, Charmane I; Suh, Christina; Tomaka, Victoria A; Crowley, Stephanie J

2015-02-11

Successful adaptation to modern civilization requires the internal circadian clock to make large phase shifts in response to circumstances (e.g., jet travel and shift work) that were not encountered during most of our evolution. We found that the magnitude and direction of the circadian clock's phase shift after the light/dark and sleep/wake/meal schedule was phase-advanced (made earlier) by 9 hours differed in European-Americans compared to African-Americans. European-Americans had larger phase shifts, but were more likely to phase-delay after the 9-hour advance (to phase shift in the wrong direction). The magnitude and direction of the phase shift was related to the free-running circadian period, and European-Americans had a longer circadian period than African-Americans. Circadian period was related to the percent Sub-Saharan African and European ancestry from DNA samples. We speculate that a short circadian period was advantageous during our evolution in Africa and lengthened with northern migrations out of Africa. The differences in circadian rhythms remaining today are relevant for understanding and treating the modern circadian-rhythm-based disorders which are due to a misalignment between the internal circadian rhythms and the times for sleep, work, school and meals.

Phase advancing human circadian rhythms with morning bright light, afternoon melatonin, and gradually shifted sleep: can we reduce morning bright light duration?

PubMed Central

Crowley, Stephanie J.; Eastman, Charmane I.

2015-01-01

OBJECTIVE Efficient treatments to phase advance human circadian rhythms are needed to attenuate circadian misalignment and the associated negative health outcomes that accompany early morning shift work, early school start times, jet lag, and delayed sleep phase disorder. This study compared three morning bright light exposure patterns from a single light box (to mimic home treatment) in combination with afternoon melatonin. METHODS Fifty adults (27 males) aged 25.9±5.1 years participated. Sleep/dark was advanced 1 hour/day for 3 treatment days. Participants took 0.5 mg melatonin 5 hours before baseline bedtime on treatment day 1, and an hour earlier each treatment day. They were exposed to one of three bright light (~5000 lux) patterns upon waking each morning: four 30-minute exposures separated by 30 minutes of room light (2 h group); four 15-minute exposures separated by 45 minutes of room light (1 h group), and one 30-minute exposure (0.5 h group). Dim light melatonin onsets (DLMOs) before and after treatment determined the phase advance. RESULTS Compared to the 2 h group (phase shift=2.4±0.8 h), smaller phase advance shifts were seen in the 1 h (1.7±0.7 h) and 0.5 h (1.8±0.8 h) groups. The 2-hour pattern produced the largest phase advance; however, the single 30-minute bright light exposure was as effective as 1 hour of bright light spread over 3.25 h, and produced 75% of the phase shift observed with 2 hours of bright light. CONCLUSIONS A 30-minute morning bright light exposure with afternoon melatonin is an efficient treatment to phase advance human circadian rhythms. PMID:25620199

Phase advancing human circadian rhythms with morning bright light, afternoon melatonin, and gradually shifted sleep: can we reduce morning bright-light duration?

PubMed

Crowley, Stephanie J; Eastman, Charmane I

2015-02-01

Efficient treatments to phase-advance human circadian rhythms are needed to attenuate circadian misalignment and the associated negative health outcomes that accompany early-morning shift work, early school start times, jet lag, and delayed sleep phase disorder. This study compared three morning bright-light exposure patterns from a single light box (to mimic home treatment) in combination with afternoon melatonin. Fifty adults (27 males) aged 25.9 ± 5.1 years participated. Sleep/dark was advanced 1 h/day for three treatment days. Participants took 0.5 mg of melatonin 5 h before the baseline bedtime on treatment day 1, and an hour earlier each treatment day. They were exposed to one of three bright-light (~5000 lux) patterns upon waking each morning: four 30-min exposures separated by 30 min of room light (2-h group), four 15-min exposures separated by 45 min of room light (1-h group), and one 30-min exposure (0.5-h group). Dim-light melatonin onsets (DLMOs) before and after treatment determined the phase advance. Compared to the 2-h group (phase shift = 2.4 ± 0.8 h), smaller phase-advance shifts were seen in the 1-h (1.7 ± 0.7 h) and 0.5-h (1.8 ± 0.8 h) groups. The 2-h pattern produced the largest phase advance; however, the single 30-min bright-light exposure was as effective as 1 h of bright light spread over 3.25 h, and it produced 75% of the phase shift observed with 2 h of bright light. A 30-min morning bright-light exposure with afternoon melatonin is an efficient treatment to phase-advance human circadian rhythms. Copyright © 2014 Elsevier B.V. All rights reserved.

Beyond Sleep Duration: Distinct Sleep Dimensions are Associated with Obesity in Children and Adolescent’s

PubMed Central

Jarrin, Denise C.; McGrath, Jennifer J.; Drake, Christopher L.

2016-01-01

Objective Short sleep duration is recognized as a significant risk factor in childhood obesity; however, the question as to how sleep contributes to the development of obesity remains largely unknown. The majority of pediatric studies have relied on sleep duration as the exclusive measure of sleep; this insular approach may be misleading given that sleep is a dynamic multidimensional construct beyond sleep duration, including sleep disturbances and patterns. While these sleep dimensions partly overlap, it is necessary to determine their independent relation with obesity, which in turn, may inform a more comprehensive understanding of putative pathophysiological mechanisms linking sleep and obesity. The aim of the present study was to investigate whether sleep dimensions including sleep duration, disturbances, and patterns were individually associated with obesity, independent of multiple covariates. The second objective was to examine whether sleep disturbances and patterns were independently associated with obesity, after adjusting for sleep duration. Method Participants included 240 healthy children and adolescents (Mage=12.60, SD=1.98; 45.8% females). Anthropometric measures included measured waist and hip circumference, body mass index Z-score and percent body fat. Subjective sleep measures included sleep duration, sleep disturbances, sleep quality, and sleep patterns from youth- and parental-report. Results Youth with larger adiposity and body composition measures reported poorer sleep quality (βavg=−0.14, p<.01), more sleep disturbances (βavg=0.13, p<.05), and showed a delayed sleep phase pattern (βavg=0.15, p<.05), independent of age, sex, pubertal status, physical activity, screen time, socioeconomic status, and sleep duration. Shorter sleep duration was significantly associated with obesity; however, this link was attenuated after adjustment of covariates. Conclusions Results suggest sleep measures beyond duration may more precisely capture influences that drive the negative association between sleep and obesity, and thus, yield more robust associations. As such, future studies are needed to better understand how distinct sleep dimensions confer risk for childhood obesity. PMID:23419602

Sleep Habits of Elementary and Middle School Children in South Texas

PubMed Central

Surani, Salim; Hesselbacher, Sean; Surani, Saherish; Sadasiva, Sreevidya; Surani, Zoya; Surani, Sara S.; Khimani, Amina; Subramanian, Shyam

2015-01-01

Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of elementary and middle school students, using the Children's Sleep Habit Questionnaire-Sleep Self-Report Form, which assessed the domains of bedtime resistance, sleep onset delay, sleep anxiety, sleep duration, night awakening, and daytime sleepiness. Results. The survey was completed by 499 elementary and 1008 middle school children. Trouble sleeping was reported by 43% in elementary school, compared with 29% of middle school children. Fifty percent of middle school children did not like sleeping, compared with 26% in elementary school. Bedtime resistance, sleep onset delay, and nighttime awakening were more common among elementary school students. Daytime sleepiness was more common among the middle school children when compared to elementary school children. Conclusions. Sleep abnormalities are present in elementary school children with changes in sleep habits into middle school. PMID:26770835

Sleep Habits of Elementary and Middle School Children in South Texas.

PubMed

Surani, Salim; Hesselbacher, Sean; Surani, Saherish; Sadasiva, Sreevidya; Surani, Zoya; Surani, Sara S; Khimani, Amina; Subramanian, Shyam

2015-01-01

Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of elementary and middle school students, using the Children's Sleep Habit Questionnaire-Sleep Self-Report Form, which assessed the domains of bedtime resistance, sleep onset delay, sleep anxiety, sleep duration, night awakening, and daytime sleepiness. Results. The survey was completed by 499 elementary and 1008 middle school children. Trouble sleeping was reported by 43% in elementary school, compared with 29% of middle school children. Fifty percent of middle school children did not like sleeping, compared with 26% in elementary school. Bedtime resistance, sleep onset delay, and nighttime awakening were more common among elementary school students. Daytime sleepiness was more common among the middle school children when compared to elementary school children. Conclusions. Sleep abnormalities are present in elementary school children with changes in sleep habits into middle school.

Sleep Problems in Infants Decrease following Massage Therapy.

ERIC Educational Resources Information Center

Field, Tiffany; Hernandez-Reif, Maria

2001-01-01

Examined the effectiveness of pre-bedtime massages for infants and toddlers with sleep onset problems. Found that, compared to bedtime stories, massages produced fewer sleep delays and a shortened latency to sleep onset. (Author/DLH)

Sleep restriction and delayed sleep associate with psychological health and biomarkers of stress and inflammation in women.

PubMed

Tartar, Jaime L; Fins, Ana I; Lopez, Andrea; Sierra, Linett A; Silverman, Sarah A; Thomas, Samuel V; Craddock, Travis J A

2015-12-01

Despite strong associations between sleep duration and health, there is no clear understanding of how volitional chronic sleep restriction (CSR) alters the physiological processes that lead to poor health in women. We focused on biochemical and psychological factors that previous research suggests are essential to uncovering the role of sleep in health. Cross-sectional study. University-based. Sixty female participants (mean age, 19.3; SD, 2.1 years). We analyzed the association between self-reported volitional CSR and time to go to sleep on a series of sleep and psychological health measures as well as biomarkers of immune functioning/inflammation (interleukin [IL]-1β), stress (cortisol), and sleep regulation (melatonin). Across multiple measures, poor sleep was associated with decreased psychological health and a reduced perception of self-reported physical health. Volitional CSR was related to increased cortisol and increased IL-1β levels. We separately looked at individuals who experienced CSR with and without delayed sleep time and found that IL-1β levels were significantly elevated in CSR alone and in CSR combined with a late sleep time. Cortisol, however, was only elevated in those women who experienced CSR combined with a late sleep time. We did not observe any changes in melatonin across groups, and melatonin levels were not related to any sleep measures. New to our study is the demonstration of how an increase in a proinflammatory process and an increase in hypothalamic-pituitary-adrenal axis activity both relate to volitional CSR, with and without a delayed sleep time. We further show how these mechanisms relate back to psychological and self-reported health in young adult women. Copyright © 2015 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Middle school start times: the importance of a good night's sleep for young adolescents.

PubMed

Wolfson, Amy R; Spaulding, Noah L; Dandrow, Craig; Baroni, Elizabeth M

2007-01-01

With the onset of adolescence, teenagers require 9.2 hr of sleep and experience a delay in the timing of sleep. In the "real world" with early school start times, however, they report less sleep, striking differences between their school-weekend sleep schedules, and significant daytime sleepiness. Prior studies demonstrated that high schoolers with later school starts do not further delay bedtime but obtain more sleep due to later wake times. This study examined sleep-wake patterns of young adolescents attending urban, public middle schools with early (7:15 a.m.) versus late (8:37 a.m.) start times. Students (N = 205) were assessed at 2 time periods. Students at the late-starting school reported waking up over 1 hr later on school mornings and obtaining 50 min more sleep each night, less sleepiness, and fewer tardies than students at the early school. All students reported similar school-night bedtime, sleep hygiene practices, and weekend sleep schedules.

Proportional-integral and proportional-integral-derivative-based cyclic sleep controllers with anti-windup technique for energy-efficient and delay-aware passive optical networks

NASA Astrophysics Data System (ADS)

Kikuchi, Takahiro; Kubo, Ryogo

2016-08-01

In energy-efficient passive optical network (PON) systems, the increase in the queuing delays caused by the power-saving mechanism of optical network units (ONUs) is an important issue. Some researchers have proposed quality-of-service (QoS)-aware ONU cyclic sleep controllers in PON systems. We have proposed proportional (P) and proportional-derivative (PD)-based controllers to maintain the average queuing delay at a constant level regardless of the amount of downstream traffic. However, sufficient performance has not been obtained because of the sleep period limitation. In this paper, proportional-integral (PI) and proportional-integral-derivative (PID)-based controllers considering the sleep period limitation, i.e., using an anti-windup (AW) technique, are proposed to improve both the QoS and power-saving performance. Simulations confirm that the proposed controllers provide better performance than conventional controllers in terms of the average downstream queuing delay and the time occupancy of ONU active periods.

Sleep to implement an intention.

PubMed

Diekelmann, Susanne; Wilhelm, Ines; Wagner, Ullrich; Born, Jan

2013-01-01

Sleep supports the consolidation of new memories. However, this effect has mainly been shown for memories of past events. Here we investigated the role of sleep for the implementation of intentions for the future. Subjects were instructed on a plan that had to be executed after a delay of 2 days. After plan instruction, subjects were either allowed to sleep or stayed awake for one night (Exp. 1) or had a 3-h sleep period either during the early night (SWS-rich sleep) or late night (REM-rich sleep; Exp. 2). In both experiments, retesting took place 2 days later after one recovery night. Sleep laboratory. A total of 56 healthy young adults participated in the study. N/A. All of the subjects who were allowed to sleep after plan instruction executed the intention 2 days later, whereas only 61% of wake subjects did so (P = 0.004; Exp. 1). Also after early SWS-rich sleep all of the subjects remembered to execute the intention, but only 55% did so after late REM-rich sleep (P = 0.015; Exp. 2). Sleep, especially SWS, plays an important role for the successful implementation of delayed intentions.

Cardiovascular regulation during sleep quantified by symbolic coupling traces

NASA Astrophysics Data System (ADS)

Suhrbier, A.; Riedl, M.; Malberg, H.; Penzel, T.; Bretthauer, G.; Kurths, J.; Wessel, N.

2010-12-01

Sleep is a complex regulated process with short periods of wakefulness and different sleep stages. These sleep stages modulate autonomous functions such as blood pressure and heart rate. The method of symbolic coupling traces (SCT) is used to analyze and quantify time-delayed coupling of these measurements during different sleep stages. The symbolic coupling traces, defined as the symmetric and diametric traces of the bivariate word distribution matrix, allow the quantification of time-delayed coupling. In this paper, the method is applied to heart rate and systolic blood pressure time series during different sleep stages for healthy controls as well as for normotensive and hypertensive patients with sleep apneas. Using the SCT, significant different cardiovascular mechanisms not only between the deep sleep and the other sleep stages but also between healthy subjects and patients can be revealed. The SCT method is applied to model systems, compared with established methods, such as cross correlation, mutual information, and cross recurrence analysis and demonstrates its advantages especially for nonstationary physiological data. As a result, SCT proves to be more specific in detecting delays of directional interactions than standard coupling analysis methods and yields additional information which cannot be measured by standard parameters of heart rate and blood pressure variability. The proposed method may help to indicate the pathological changes in cardiovascular regulation and also the effects of continuous positive airway pressure therapy on the cardiovascular system.

The Effects of Sleep on Emotional Target Detection Performance: A Novel iPad-Based Pediatric Game

PubMed Central

Colonna, Annalisa; Smith, Anna B.; Smith, Stuart; VanDenEshof, Kirandeep; Orgill, Jane; Gringras, Paul; Pal, Deb K.

2018-01-01

Background: Consolidation of learning occurs during sleep but when it is disturbed there may be an adverse impact upon these functions. While research has focused upon how sleep affects cognition in adulthood, the effects of disrupted sleep are likely to impact more heavily on learning among children and adolescents. We aimed to investigate whether a night’s sleep impacts upon executive function compared with an equivalent wakefulness period. We also wanted to know whether restricting sleep would reduce these effects on performance. To investigate this issue in children, we adapted existing research methods to make them more suitable for this population. Methods: Using a cross-over trial design, 22 children aged 7–14 completed an updated but previously validated, continuous performance task (CPT) designed to be appealing to children, containing emotional and neutral targets and presented on an iPad. We measured omission and commission errors, mean and variability of reaction times (RTs) immediately and after a delay spent in the following three ways: 11-h intervals of unrestricted and restricted sleep in the style of a ‘sleepover’ and daytime wakefulness. We examined differences in immediate and delayed testing for each dependent variable. Both sleep nights were spent in a specialist sleep lab where polysomnography data were recorded. Results: While there were no significant main effects of sleep condition, as expected we observed significantly faster and more accurate performance in delayed compared with immediate testing across all conditions for omission errors, RT and variability of RT. Importantly, we saw a significant interaction for commission errors to emotional targets (p = 0.034): while they were comparable across all conditions during immediate testing, for delayed testing there were significantly more errors after wakefulness compared with unrestricted sleep (p = 0.019) and at a trend level for restricted sleep (p = 0.063). Performance improvement after restricted sleep was inversely correlated with sleep opportunity time (p = 0.03), total sleep time (p = 0.01) and total non-REM time (p = 0.005). Conclusion: This tool, designed to be simple to use and appealing to children, revealed a preserving effect of typical and disrupted sleep periods on performance during an emotionally themed target detection task compared with an equivalent wakefulness period. PMID:29563887

Impact of Common Diabetes Risk Variant in MTNR1B on Sleep, Circadian, and Melatonin Physiology.

PubMed

Lane, Jacqueline M; Chang, Anne-Marie; Bjonnes, Andrew C; Aeschbach, Daniel; Anderson, Clare; Cade, Brian E; Cain, Sean W; Czeisler, Charles A; Gharib, Sina A; Gooley, Joshua J; Gottlieb, Daniel J; Grant, Struan F A; Klerman, Elizabeth B; Lauderdale, Diane S; Lockley, Steven W; Munch, Miriam; Patel, Sanjay; Punjabi, Naresh M; Rajaratnam, Shanthakumar M W; Rueger, Melanie; St Hilaire, Melissa A; Santhi, Nayantara; Scheuermaier, Karin; Van Reen, Eliza; Zee, Phyllis C; Shea, Steven A; Duffy, Jeanne F; Buxton, Orfeu M; Redline, Susan; Scheer, Frank A J L; Saxena, Richa

2016-06-01

The risk of type 2 diabetes (T2D) is increased by abnormalities in sleep quantity and quality, circadian alignment, and melatonin regulation. A common genetic variant in a receptor for the circadian-regulated hormone melatonin (MTNR1B) is associated with increased fasting blood glucose and risk of T2D, but whether sleep or circadian disruption mediates this risk is unknown. We aimed to test if MTNR1B diabetes risk variant rs10830963 associates with measures of sleep or circadian physiology in intensive in-laboratory protocols (n = 58-96) or cross-sectional studies with sleep quantity and quality and timing measures from self-report (n = 4,307-10,332), actigraphy (n = 1,513), or polysomnography (n = 3,021). In the in-laboratory studies, we found a significant association with a substantially longer duration of elevated melatonin levels (41 min) and delayed circadian phase of dim-light melatonin offset (1.37 h), partially mediated through delayed offset of melatonin synthesis. Furthermore, increased T2D risk in MTNR1B risk allele carriers was more pronounced in early risers versus late risers as determined by 7 days of actigraphy. Our results provide the surprising insight that the MTNR1B risk allele influences dynamics of melatonin secretion, generating a novel hypothesis that the MTNR1B risk allele may extend the duration of endogenous melatonin production later into the morning and that early waking may magnify the diabetes risk conferred by the risk allele. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Insomnia in childhood and adolescence: clinical aspects, diagnosis, and therapeutic approach.

PubMed

Nunes, Magda Lahorgue; Bruni, Oliviero

2015-01-01

To review the clinical characteristics, comorbidities, and management of insomnia in childhood and adolescence. This was a non-systematic literature review carried out in the PubMed database, from where articles published in the last five years were selected, using the key word "insomnia" and the pediatric age group filter. Additionally, the study also included articles and classic textbooks of the literature on the subject. During childhood, there is a predominance of behavioral insomnia as a form of sleep-onset association disorder (SOAD) and/or limit-setting sleep disorder. Adolescent insomnia is more associated with sleep hygiene problems and delayed sleep phase. Psychiatric (anxiety, depression) or neurodevelopmental disorders (attention deficit disorder, autism, epilepsy) frequently occur in association with or as a comorbidity of insomnia. Insomnia complaints in children and adolescents should be taken into account and appropriately investigated by the pediatrician, considering the association with several comorbidities, which must also be diagnosed. The main causes of insomnia and triggering factors vary according to age and development level. The therapeutic approach must include sleep hygiene and behavioral techniques and, in individual cases, pharmacological treatment. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Bright-light exposure during daytime sleeping affects nocturnal melatonin secretion after simulated night work.

PubMed

Nagashima, Shunsuke; Osawa, Madoka; Matsuyama, Hiroto; Ohoka, Wataru; Ahn, Aemi; Wakamura, Tomoko

2018-02-01

The guidelines for night and shift workers recommend that after night work, they should sleep in a dark environment during the daytime. However, staying in a dark environment during the daytime reduces nocturnal melatonin secretion and delays its onset. Daytime bright-light exposure after night work is important for melatonin synthesis the subsequent night and for maintaining the circadian rhythms. However, it is not clear whether daytime sleeping after night work should be in a dim- or a bright-light environment for maintaining melatonin secretion. The aim of this study, therefore, was to evaluate the effect of bright-light exposure during daytime sleeping on nocturnal melatonin secretion after simulated night work. Twelve healthy male subjects, aged 24.8 ± 4.6 (mean ± SD), participated in 3-day sessions under two experimental conditions, bright light or dim light, in a random order. On the first day, the subjects entered the experimental room at 16:00 and saliva samples were collected every hour between 18:00 and 00:00 under dim-light conditions. Between 00:00 and 08:00, they participated in tasks that simulated night work. At 10:00 the next morning, they slept for 6 hours under either a bright-light condition (>3000 lx) or a dim-light condition (<50 lx). In the evening, saliva samples were collected as on the first day. The saliva samples were analyzed for melatonin concentration. Activity and sleep times were recorded by a wrist device worn throughout the experiment. In the statistical analysis, the time courses of melatonin concentration were compared between the two conditions by three-way repeated measurements ANOVA (light condition, day and time of day). The change in dim light melatonin onset (ΔDLMO) between the first and second days, and daytime and nocturnal sleep parameters after the simulated night work were compared between the light conditions using paired t-tests. The ANOVA results indicated a significant interaction (light condition and3 day) (p = .006). Post hoc tests indicated that in the dim-light condition, the melatonin concentration was significantly lower on the second day than on the first day (p = .046); however, in the bright-light condition, there was no significant difference in the melatonin concentration between the days (p = .560). There was a significant difference in ΔDLMO between the conditions (p = .015): DLMO after sleeping was advanced by 11.1 ± 17.4 min under bright-light conditions but delayed for 7.2 ± 13.6 min after sleeping under dim-light conditions. No significant differences were found in any sleep parameter. Our study demonstrated that daytime sleeping under bright-light conditions after night work could not reduce late evening melatonin secretion until midnight or delay the phase of melatonin secretion without decreasing the quality of the daytime sleeping. Thus, these results suggested that, to enhance melatonin secretion and to maintain their conventional sleep-wake cycle, after night work, shift workers should sleep during the daytime under bright-light conditions rather than dim-light conditions.

Acquired auditory agnosia in childhood and normal sleep electroencephalography subsequently diagnosed as Landau-Kleffner syndrome: a report of three cases.

PubMed

van Bogaert, Patrick; King, Mary D; Paquier, Philippe; Wetzburger, Catherine; Labasse, Catherine; Dubru, Jean-Marie; Deonna, Thierry

2013-06-01

  We report three cases of Landau-Kleffner syndrome (LKS) in children (two females, one male) in whom diagnosis was delayed because the sleep electroencephalography (EEG) was initially normal.   Case histories including EEG, positron emission tomography findings, and long-term outcome were reviewed.   Auditory agnosia occurred between the age of 2 years and 3 years 6 months, after a period of normal language development. Initial awake and sleep EEG, recorded weeks to months after the onset of language regression, during a nap period in two cases and during a full night of sleep in the third case, was normal. Repeat EEG between 2 months and 2 years later showed epileptiform discharges during wakefulness and strongly activated by sleep, with a pattern of continuous spike-waves during slow-wave sleep in two patients. Patients were diagnosed with LKS and treated with various antiepileptic regimens, including corticosteroids. One patient in whom EEG became normal on hydrocortisone is making significant recovery. The other two patients did not exhibit a sustained response to treatment and remained severely impaired.   Sleep EEG may be normal in the early phase of acquired auditory agnosia. EEG should be repeated frequently in individuals in whom a firm clinical diagnosis is made to facilitate early treatment. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Evaluation of salivary melatonin measurements for Dim Light Melatonin Onset calculations in patients with possible sleep-wake rhythm disorders.

PubMed

Keijzer, Henry; Smits, Marcel G; Peeters, Twan; Looman, Caspar W N; Endenburg, Silvia C; Gunnewiek, Jacqueline M T Klein

2011-08-17

Dim Light Melatonin Onset (DLMO) can be calculated within a 5-point partial melatonin curve in saliva collected at home. We retrospectively analyzed the patient melatonin measurements sample size of the year 2008 to evaluate these DLMO calculations and studied the correlation between diary or polysomnography (PSG) sleep onset and DLMO. Patients completed an online questionnaire. If this questionnaire pointed to a possible Delayed Sleep Phase Disorder (DSPD), saliva collection devices were sent to the patient. Collection occurred at 5 consecutive hours. Melatonin concentration was measured with a radioimmunoassay and DLMO was defined as the time at which the melatonin concentration in saliva reaches 4 pg/mL. Sleep onset time was retrieved from an online one-week sleep diary and/or one-night PSG. A total of 1848 diagnostic 5-point curves were obtained. DLMO could be determined in 76.2% (n=1408). DLMO significantly differed between different age groups and increased with age. Pearson correlations (r) between DLMO and sleep onset measured with PSG or with a diary were 0.514 (p=<0.001, n=54) and 0.653 (p=0.002, n=20) respectively. DLMO can be reliably measured in saliva that is conveniently collected at home. DLMO correlates moderately with sleep onset. Copyright © 2011 Elsevier B.V. All rights reserved.

Circadian Periods of Sensitivity for Ramelteon on the onset of Running-wheel Activity and the Peak of Suprachiasmatic Nucleus Neuronal Firing Rhythms in C3H/HeN Mice

PubMed Central

Rawashdeh, Oliver; Hudson, Randall L.; Stepien, Iwona; Dubocovich, Margarita L.

2016-01-01

Ramelteon, an MT1/MT2 melatonin receptor agonist, is used for the treatment of sleep-onset insomnia and circadian sleep disorders. Ramelteon phase shifts circadian rhythms in rodents and humans when given at the end of the subjective day; however, its efficacy at other circadian times is not known. Here, the authors determined in C3H/ HeN mice the maximal circadian sensitivity for ramelteon in vivo on the onset of circadian running-wheel activity rhythms, and in vitro on the peak of circadian rhythm of neuronal firing in suprachiasmatic nucleus (SCN) brain slices. The phase response curve (PRC) for ramelteon (90 μg/mouse, subcutaneous [sc]) on circadian wheel-activity rhythms shows maximal sensitivity during the late mid to end of the subjective day, between CT8 and CT12 (phase advance), and late subjective night and early subjective day, between CT20 and CT2 (phase delay), using a 3-day-pulse treatment regimen in C3H/HeN mice. The PRC for ramelteon resembles that for melatonin in C3H/ HeN mice, showing the same magnitude of maximal shifts at CT10 and CT2, except that the range of sensitivity for ramelteon (CT8–CT12) during the subjective day is broader. Furthermore, in SCN brain slices in vitro, ramelteon (10 pM) administered at CT10 phase advances (5.6 ± 0.29 h, n = 3) and at CT2 phase delays (−3.2 ± 0.12 h, n = 6) the peak of circadian rhythm of neuronal firing, with the shifts being significantly larger than those induced by melatonin (10 pM) at the same circadian times (CT10: 2.7 ± 0.15 h, n = 4, p < .05; CT2: −1.13 ± 0.08 h, n = 6, p < .001, respectively). The phase shifts induced by both melatonin and ramelteon in the SCN brain slice at either CT10 or CT2 corresponded with the period of sensitivity observed in vivo. In conclusion, melatonin and ramelteon showed identical periods of circadian sensitivity at CT10 (advance) and CT2 (delay) to shift the onset of circadian activity rhythms in vivo and the peak of SCN neuronal firing rhythms in vitro. PMID:21182402

Applying behavioral insights to delay school start times.

PubMed

Kohl Malone, Susan; Ziporyn, Terra; Buttenheim, Alison M

2017-12-01

Healthy People 2020 established a national objective to increase the proportion of 9th-to-12th-grade students reporting sufficient sleep. A salient approach for achieving this objective is to delay middle and high school start times. Despite decades of research supporting the benefits of delayed school start times on adolescent sleep, health, and well-being, progress has been slow. Accelerating progress will require new approaches incorporating strategies that influence how school policy decisions are made. In this commentary, we introduce four strategies that influence decision-making processes and demonstrate how they can be applied to efforts aimed at changing school start time policies. Copyright © 2017 National Sleep Foundation. All rights reserved.

Delaying Middle School and High School Start Times Promotes Student Health and Performance: An American Academy of Sleep Medicine Position Statement

PubMed Central

Watson, Nathaniel F.; Martin, Jennifer L.; Wise, Merrill S.; Carden, Kelly A.; Kirsch, Douglas B.; Kristo, David A.; Malhotra, Raman K.; Olson, Eric J.; Ramar, Kannan; Rosen, Ilene M.; Rowley, James A.; Weaver, Terri E.; Chervin, Ronald D.

2017-01-01

During adolescence, internal circadian rhythms and biological sleep drive change to result in later sleep and wake times. As a result of these changes, early middle school and high school start times curtail sleep, hamper a student's preparedness to learn, negatively impact physical and mental health, and impair driving safety. Furthermore, a growing body of evidence shows that delaying school start times positively impacts student achievement, health, and safety. Public awareness of the hazards of early school start times and the benefits of later start times are largely unappreciated. As a result, the American Academy of Sleep Medicine is calling on communities, school boards, and educational institutions to implement start times of 8:30 AM or later for middle schools and high schools to ensure that every student arrives at school healthy, awake, alert, and ready to learn. Citation: Watson NF, Martin JL, Wise MS, Carden KA, Kirsch DB, Kristo DA, Malhotra RK, Olson EJ, Ramar K, Rosen IM, Rowley JA, Weaver TE, Chervin RD. Delaying middle school and high school start times promotes student health and performance: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2017;13(4):623–625. PMID:28416043

Sleep deficits in the High Arctic summer in relation to light exposure and behaviour: use of melatonin as a countermeasure.

PubMed

Paul, Michel A; Love, Ryan J; Hawton, Andrea; Brett, Kaighley; McCreary, Donald R; Arendt, Josephine

2015-03-01

There are conflicting reports regarding seasonal sleep difficulties in polar regions. Herein we report differences in actigraphic sleep measures between two summer trials (collected at Canadian Forces Station Alert, 82.5°N, in 2012 and 2014) and evaluate exogenous melatonin for preventing/treating circadian phase delay due to nocturnal light exposure. Subjects wore actigraphs continuously to obtain sleep data. Following seven days of actigraphic recording the subjects filled out questionnaires regarding sleep difficulty and psychosocial parameters and subsequently remained in dim light conditions for 24 hours, during which saliva was collected bihourly to measure melatonin. During Trial 2, individuals who reported difficulty sleeping were prescribed melatonin, and a second saliva collection was conducted to evaluate the effect of melatonin on the circadian system. Trial 1 subjects collectively had late dim light melatonin onsets and difficulty sleeping; however, the Trial 2 subjects had normally timed melatonin rhythms, and obtained a good quantity of high-quality sleep. Nocturnal light exposure was significantly different between the trials, with Trial 1 subjects exposed to significantly more light between 2200 and 0200h. Melatonin treatment during Trial 2 led to an improvement in the subjective sleep difficulty between the pre- and post-treatment surveys; however there were no significant differences in the objective measures of sleep. The difference in sleep and melatonin rhythms between research participants in June 2012 and June 2014 is attributed to the higher levels of nocturnal light exposure in 2012. The avoidance of nocturnal light is likely to improve sleep during the Arctic summer. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Sleep deprivation alters effort discounting but not delay discounting of monetary rewards.

PubMed

Libedinsky, Camilo; Massar, Stijn A A; Ling, Aiqing; Chee, Weiyan; Huettel, Scott A; Chee, Michael W L

2013-06-01

To determine whether sleep deprivation would affect the discounting of delayed rewards, of rewards entailing the expense of effort, or both. We measured rates of two types of reward discounting under conditions of rested wakefulness (RW) and sleep deprivation (SD). Delay discounting was defined as the willingness to accept smaller monetary rewards sooner rather than larger monetary rewards later. Effort discounting was defined as the willingness to accept smaller rewards that require less effort to obtain (e.g., typing a small number of letter strings backward) over larger but more effortful rewards (e.g., typing more letter strings to receive the reward). The first two experiments used a crossover design in which one session was conducted after a normal night of sleep (RW), and the other after a night without sleep (SD). The first experiment evaluated only temporal discounting whereas the second evaluated temporal and effort discounting. In the second experiment, the discounting tasks were repeatedly administered prior to the state comparisons to minimize the effects of order and/or repeated testing. In a third experiment, participants were studied only once in a between-subject evaluation of discounting across states. The study took place in a research laboratory. Seventy-seven healthy young adult participants: 20 in Experiment 1, 27 in Experiment 2, and 30 in Experiment 3. N/A. Sleep deprivation elicited increased effort discounting but did not affect delay discounting. The dissociable effects of sleep deprivation on two forms of discounting behavior suggest that they may have differing underlying neural mechanisms.

Pathways Linking Adverse Childhood Experiences to Cigarette Smoking Among Young Black Men: a Prospective Analysis of the Role of Sleep Problems and Delayed Reward Discounting.

PubMed

Oshri, Assaf; Kogan, Steven; Liu, Sihong; Sweet, Lawrence; Mackillop, James

2017-12-01

African American men experience increases in smoking during the young adult transition. Exposure to childhood adversity, a risk factor which disproportionately affects African American men, has been identified as a robust precursor to health risk behavior in general and cigarette smoking in particular. The intermediate mechanisms that transmit the influence of early adversity to smoking behavior are not well understood. We tested a model of the escalation of smoking behaviors among young adult African American men, investigating sleep disturbance and delayed reward discounting as intermediate factors linking adverse childhood experiences with smoking. Hypotheses were tested with three waves of data (M age-T1  = 20.34, M age-T2  = 21.92, M age-T3  = 23.02) from 505 African American men living in rural counties in South Georgia. Men provided self-report data on their adverse childhood experiences, sleep problems, and smoking behavior using audio-assisted computer self-interviews. Men also completed a computer-based delayed reward discounting task. Structural equation modeling analyses supported our hypotheses: Adverse childhood experiences predicted poor sleep adequacy, which forecast increases in delayed reward discounting; discounting, in turn, predicted increased smoking. Significant indirect pathways were detected linking adversity to discounting via sleep adequacy and linking sleep adequacy to smoking via discounting. Prevention and intervention researchers can draw on these findings to develop programs that focus on sleep adequacy to reduce smoking in African American men exposed to childhood adversity.

Cognitive-Behavior Therapy for Late-Life Insomnia.

ERIC Educational Resources Information Center

Morin, Charles M.; And Others

1993-01-01

Assigned 24 older adults with persistent psychophysiological insomnia to immediate or delayed cognitive-behavioral intervention in waiting-list control group design. Treatment was effective in reducing sleep latency, wake after sleep onset, and early morning awakening, and in increasing sleep efficiency. Sleep improvements obtained by…

Sleep Patterns and Mental Health Correlates in US Adolescents.

PubMed

Zhang, Jihui; Paksarian, Diana; Lamers, Femke; Hickie, Ian B; He, Jianping; Merikangas, Kathleen Ries

2017-03-01

To investigate systematically the associations of sleep patterns with a range of mental disorders and other outcomes among a nationally representative sample of US adolescents. Using the National Comorbidity Survey Adolescent Supplement, a nationally representative cross-sectional survey of 10 123 US adolescents 13-18 years of age, we assessed associations between adolescent-reported sleep patterns (tertiles of weeknight bedtime, weeknight sleep duration, weekend bedtime delay, and weekend oversleep) and past-year mental disorders based on the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, smoking, injury, suicidality, and perceived mental and physical health, assessed via direct diagnostic interview. The average weeknight bedtime was at 22:37 and sleep duration was 7.72 hours. Average weekend bedtime delay was 1.81 hours and average weekend oversleep was 1.17 hours. Later weeknight bedtime, shorter weeknight sleep duration, greater weekend bedtime delay, and both short and long periods of weekend oversleep were associated with increased odds of mood, anxiety, substance use, and behavioral disorders, as well as suicidality, tobacco smoking, and poor perceived mental and physical health. ORs ranged from 1.27 to 2.15. The only outcomes not associated with any sleep patterns were past-year injury and eating disorder. Suboptimal sleep patterns were associated with an array of mental disorders and other health-related outcomes among adolescents. Abnormal sleep patterns may serve as markers of prodromal or untreated mental disorders among adolescents, and may provide opportunities for prevention and intervention in mental disorders. Copyright © 2016. Published by Elsevier Inc.

Controlled patterns of daytime light exposure improve circadian adjustment in simulated night work.

PubMed

Dumont, Marie; Blais, Hélène; Roy, Joanie; Paquet, Jean

2009-10-01

Circadian misalignment between the endogenous circadian signal and the imposed rest-activity cycle is one of the main sources of sleep and health troubles in night shift workers. Timed bright light exposure during night work can reduce circadian misalignment in night workers, but this approach is limited by difficulties in incorporating bright light treatment into most workplaces. Controlled light and dark exposure during the daytime also has a significant impact on circadian phase and could be easier to implement in real-life situations. The authors previously described distinctive light exposure patterns in night nurses with and without circadian adaptation. In the present study, the main features of these patterns were used to design daytime light exposure profiles. Profiles were then tested in a laboratory simulation of night work to evaluate their efficacy in reducing circadian misalignment in night workers. The simulation included 2 day shifts followed by 4 consecutive night shifts (2400-0800 h). Healthy subjects (15 men and 23 women; 20-35 years old) were divided into 3 groups to test 3 daytime light exposure profiles designed to produce respectively a phase delay (delay group, n=12), a phase advance (advance group, n=13), or an unchanged circadian phase (stable group, n=13). In all 3 groups, light intensity was set at 50 lux during the nights of simulated night work. Salivary dim light melatonin onset (DLMO) showed a significant phase advance of 2.3 h (+/-1.3 h) in the advance group and a significant phase delay of 4.1 h (+/-1.3 h) in the delay group. The stable group showed a smaller but significant phase delay of 1.7 h (+/-1.6 h). Urinary 6-sulfatoxymelatonin (aMT6s) acrophases were highly correlated to salivary DLMOs. Urinary aMT6s acrophases were used to track daily phase shifts. They showed that phase shifts occurred rapidly and differed between the 3 groups by the 3rd night of simulated night work. These results show that significant phase shifts can be achieved in night workers by controlling daytime light exposure, with no nighttime intervention.

Complete or partial circadian re-entrainment improves performance, alertness, and mood during night-shift work.

PubMed

Crowley, Stephanie J; Lee, Clara; Tseng, Christine Y; Fogg, Louis F; Eastman, Charmane I

2004-09-15

To assess performance, alertness, and mood during the night shift and subsequent daytime sleep in relation to the degree of re-alignment (re-entrainment) of circadian rhythms with a night-work, day-sleep schedule. Subjects spent 5 consecutive night shifts (11:00 pm-7:00 am) in the lab and slept at home in darkened bedrooms (8:30 am-3:30 pm). Subjects were categorized by the degree of re-entrainment attained after the 5 night shifts. Completely re-entrained: temperature minimum in the second half of daytime sleep; partially re-entrained: temperature minimum in the first half of daytime sleep; not re-entrained: temperature minimum did not delay enough to reach daytime sleep. See above. Young healthy adults (n = 67) who were not shift workers. Included bright light during the night shifts, sunglasses worn outside, a fixed dark daytime sleep episode, and melatonin. The effects of various combinations of these interventions on circadian re-entrainment were previously reported. Here we report how the degree of re-entrainment affected daytime sleep and measures collected during the night shift. Salivary melatonin was collected every 30 minutes in dim light (<20 lux) before and after the night shifts to determine the dim light melatonin onset, and the temperature minimum was estimated by adding a constant (7 hours) to the dim light melatonin onset. Subjects kept sleep logs, which were verified by actigraphy. The Neurobehavioral Assessment Battery was completed several times during each night shift. Baseline sleep schedules and circadian phase differed among the 3 re-entrainment groups, with later times resulting in more re-entrainment. The Neurobehavioral Assessment Battery showed that performance, sleepiness, and mood were better in the groups that re-entrained compared to the group that did not re-entrain, but there were no significant differences between the partial and complete re-entrainment groups. Subjects slept almost all of the allotted 7 hours during the day, and duration did not significantly differ among the re-entrainment groups. In young people, complete re-entrainment to the night-shift day-sleep schedule is not necessary to produce substantial benefits in neurobehavioral measures; partial re-entrainment (delaying the temperature minimum into the beginning of daytime sleep) is sufficient. The group that did not re-entrain shows that a reasonable amount of daytime sleep is not enough to produce good neurobehavioral performance during the night shift. Therefore, some re-alignment of circadian rhythms is recommended.

Dual conception of risk in the Iowa Gambling Task: effects of sleep deprivation and test-retest gap.

PubMed

Singh, Varsha

2013-01-01

Risk in the Iowa Gambling Task (IGT) is often understood in terms of intertemporal choices, i.e., preference for immediate outcomes in favor of delayed outcomes is considered risky decision making. According to behavioral economics, healthy decision makers are expected to refrain from choosing the short-sighted immediate gain because, over time (10 trials of the IGT), the immediate gains result in a long term loss (net loss). Instead decision makers are expected to maximize their gains by choosing options that, over time (10 trials), result in delayed or long term gains (net gain). However, task choices are sometimes made on the basis of the frequency of reward and punishment such that frequent rewards/infrequent punishments are favored over infrequent rewards/frequent punishments. The presence of these two attributes (intertemporality and frequency of reward) in IGT decision making may correspond to the emotion-cognition dichotomy and reflect a dual conception of risk. Decision making on the basis of the two attributes was tested under two conditions: delay in retest and sleep deprivation. An interaction between sleep deprivation and time delay was expected to attenuate the difference between the two attributes. Participants were 40 male university students. Analysis of the effects of IGT attribute type (intertemporal vs. frequency of reinforcement), sleep deprivation (sleep deprivation vs. no sleep deprivation), and test-retest gap (short vs. long delay) showed a significant within-subjects effect of IGT attribute type thus confirming the difference between the two attributes. Sleep deprivation had no effect on the attributes, but test-retest gap and the three-way interaction between attribute type, test-retest gap, and sleep deprivation were significantly different. Post-hoc tests revealed that sleep deprivation and short test-retest gap attenuated the difference between the two attributes. Furthermore, the results showed an expected trend of increase in intertemporal decision making at retest suggesting that intertemporal decision making benefited from repeated task exposure. The present findings add to understanding of the emotion-cognition dichotomy. Further, they show an important time-dependent effect of a universally experienced constraint (sleep deprivation) on decision making. It is concluded that risky decision making in the IGT is contingent on the attribute under consideration and is affected by factors such as time elapsed and constraint experienced before the retest.

Associations between sleep-wake consolidation and language development in early childhood: a longitudinal twin study.

PubMed

Dionne, Ginette; Touchette, Evelyne; Forget-Dubois, Nadine; Petit, Dominique; Tremblay, Richard E; Montplaisir, Jacques Y; Boivin, Michel

2011-08-01

The objectives were (1) to assess associations between sleep consolidation at 6, 18 and 30 months and language skills at 18, 30, and 60 months; and (2) to investigate the genetic/environmental etiology of these associations. Longitudinal study of a population-based twin cohort. 1029 twins from the Quebec Newborn Twin Study. Sleep consolidation was derived from parental reports of day/night consecutive sleeping durations. Language skills were assessed with the MacArthur Communicative Development Inventory at 18 and 30 months and the Peabody Picture Vocabulary Test at 60 months. The day/night sleep ratio decreased significantly from 6 to 30 months. The 6- and 18-month ratios were negatively correlated with subsequent language skills. Children with language delays at 60 months had less mature sleep consolidation at both 6 and 18 months than children without delays and those with transient early delays. Genetic and regression analyses revealed that the sleep ratio at 6 months was highly heritable (64%) and predicted 18-month (B = -0.06) and 30-month language (B = -0.11) mainly through additive genetic influences (R(Gs) = 0.32 and 0.33, respectively). By contrast, the sleep ratio at 18 months was mainly due to shared environment influences (58%) and predicted 60-month language (B = -0.08) through shared environment influences (R(Cs) = 0.24). Poor sleep consolidation during the first 2 years of life may be a risk factor for language learning, whereas good sleep consolidation may foster language learning through successive genetic and environmental influences.

Description of a Sleep-Restriction Program to Reduce Bedtime Disturbances and Night Waking

ERIC Educational Resources Information Center

Durand, V. Mark; Christodulu, Kristin V.

2004-01-01

The authors describe a behavioral intervention designed to reduce sleep problems without increasing disruption at bedtime or throughout the evening. Sleep restriction was used to reduce the bedtime and nighttime sleep problems of two children, a 4-year-old girl with autism and a 4-year-old girl with developmental delay. Sleep restriction involved…

Significant Sleep Dysregulation in a Toddler With Developmental Delay.

PubMed

Stein, Martin T; Owens, Judith; Abbott, Myles

Derrick's parents made an appointment with a new pediatrician for a second opinion about disordered sleep. Now 22-months old, he was evaluated at 18 months of age for developmental delay when he was found to have "a regulatory disorder associated with delays in language and motor development, hypotonia and significant sleep problems." The parents are now most concerned about his sleeping pattern. Prolonged sleep onset and frequent night awaking occur each night since 6-months of age. These problems are more severe in the past few months when he awakes screaming and cannot be settled. The awakening episodes occur 2 to 4 times each night when "he screams and thrashes his body for up to an hour." Daytime tantrums increased. After the parents read a book about sleep in young children, they provided a calm atmosphere at bedtime including a dark room and singing a quiet lullaby. When these changes did not alter sleep, they purchased a vibrating mattress which was also unsuccessful.Derrick was born full term after an uncomplicated prenatal and perinatal course. He sat at 10 months, crawled at 12 months, and walked at 18 months. He currently drinks from a sippy cup and he can use a utensil to eat. He has few words saying only "no" and "mama" in the past month. Imitation of some words occurred recently. He has responded to simple directions in the past 2 months. Derrick passed the newborn audiology screen. He does not have difficulty swallowing and he does not drool. He plays with many different toys and he plays in parallel with his older brother who also experienced delays in motor and language development. His brother is now doing very well in school. There is no family history of cognitive delay, seizure disorder, cerebral palsy, early developmental delay (other than the brother) or a significant sleep problem. PHYSICAL EXAMINATION:: head circumference, length and weight (75th percentile). He had mild generalized hypotonia, mild weakness, 2+ symmetrical deep tendon reflexes, and absence of ankle clonus. His gait was slightly wide based, steady, and without a limp. Neither ataxia nor drooling was observed. He was easily engaged in play with the examiner without evidence of irritability. The remainder of the examination was normal.

Human seasonal and circadian studies in Antarctica (Halley, 75°S).

PubMed

Arendt, Josephine; Middleton, Benita

2018-03-01

Living for extended periods in Antarctica exposes base personnel to extremes of daylength (photoperiod) and temperature. At the British Antarctic Survey base of Halley, 75°S, the sun does not rise for 110 d in the winter and does not set for 100 d in summer. Photoperiod is the major time cue governing the timing of seasonal events such as reproduction in many species. The neuroendocrine signal providing photoperiodic information to body physiology is the duration of melatonin secretion which reflects the length of the night: longer in the short days of winter and shorter in summer. Light of sufficient intensity and spectral composition serves to suppress production of melatonin and to set the circadian timing and the duration of the rhythm. In humans early observations suggested that bright (>2000 lux) white light was needed to suppress melatonin completely. Shortly thereafter winter depression (Seasonal Affective Disorder or SAD) was described, and its successful treatment by an artificial summer photoperiod of bright white light, sufficient to shorten melatonin production. At Halley dim artificial light intensity during winter was measured, until 2003, at a maximum of approximately 500 lux in winter. Thus a strong seasonal and circadian time cue was absent. It seemed likely that winter depression would be common in the extended period of winter darkness and could be treated with an artificial summer photoperiod. These observations, and predictions, inspired a long series of studies regarding human seasonal and circadian status, and the effects of light treatment, in a small overwintering, isolated community, living in the same conditions for many months at Halley. We found little evidence of SAD, or change in duration of melatonin production with season. However the timing of the melatonin rhythm itself, and/or that of its metabolite 6-sulphatoxymelatonin (aMT6s), was used as a primary marker of seasonal, circadian and treatment changes. A substantial phase delay of melatonin in winter was advanced to summer phase by a two pulse 'skeleton' bright white light treatment. Subsequently a single morning pulse of bright white light was effective with regard to circadian phase and improved daytime performance. The circadian delay evidenced by melatonin was accompanied by delayed sleep (logs and actigraphy): poor sleep is a common complaint in Polar regions. Appropriate extra artificial light, both standard white, and blue enriched, present throughout the day, effectively countered delay in sleep timing and the aMT6s rhythm. The most important factor appeared to be the maximum light experienced. Another manifestation of the winter was a decline in self-rated libido (men only on base at this time). Women on the base showed lower aspects of physical and mental health compared to men. Free-running rhythms were seen in some subjects following night shift, but were rarely found at other times, probably because this base has strongly scheduled activity and leisure time. Complete circadian adaptation during a week of night shift, also seen in a similar situation on North Sea oil rigs, led to problems readapting back to day shift in winter, compared to summer. Here again timed light treatment was used to address the problem. Sleep, alertness and waking performance are critically dependent on optimum circadian phase. Circadian desynchrony is associated with increased risk of major disease in shift workers. These studies provide some groundwork for countering/avoiding circadian desynchrony in rather extreme conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Delayed school start time is associated with better sleep, daytime functioning, and life satisfaction in residential high-school students.

PubMed

Chan, Christian S; Poon, Cyanea Y S; Leung, Jacklyn C Y; Lau, Kristy N T; Lau, Esther Y Y

2018-05-16

The effects of a delayed school start time by one hour were examined at a boarding school in Hong Kong. Two cohorts of high school students (N = 228; 61.8% female) were recruited respectively before and after a school start time changed from 7:30am to 8:30am. Both cross-cohort and within-cohort longitudinal comparisons yielded significant increase in total sleep time. Cross-cohort comparison yielded improvement in sleep quality, insomnia, life satisfaction, and psychological distress. Longitudinal data suggested that the longer the additional sleep time, the better was sleep quality, day-time functioning, and subjective wellbeing. Copyright © 2018 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Delaying Middle School and High School Start Times Promotes Student Health and Performance: An American Academy of Sleep Medicine Position Statement.

PubMed

Watson, Nathaniel F; Martin, Jennifer L; Wise, Merrill S; Carden, Kelly A; Kirsch, Douglas B; Kristo, David A; Malhotra, Raman K; Olson, Eric J; Ramar, Kannan; Rosen, Ilene M; Rowley, James A; Weaver, Terri E; Chervin, Ronald D

2017-04-15

During adolescence, internal circadian rhythms and biological sleep drive change to result in later sleep and wake times. As a result of these changes, early middle school and high school start times curtail sleep, hamper a student's preparedness to learn, negatively impact physical and mental health, and impair driving safety. Furthermore, a growing body of evidence shows that delaying school start times positively impacts student achievement, health, and safety. Public awareness of the hazards of early school start times and the benefits of later start times are largely unappreciated. As a result, the American Academy of Sleep Medicine is calling on communities, school boards, and educational institutions to implement start times of 8:30 AM or later for middle schools and high schools to ensure that every student arrives at school healthy, awake, alert, and ready to learn. © 2017 American Academy of Sleep Medicine

Interactive Effects of Delayed Bedtime and Family-Associated Factors on Depression in Elementary School Children

ERIC Educational Resources Information Center

Lin, Jin-Ding; Tung, Ho-Jui; Hsieh, Yu-Hsin; Lin, Fu-Gong

2011-01-01

Shorter sleep time was reported to be associated with psychological functioning in children. We intended to examine the relationship between nocturnal sleep duration and depression status by investigating if delayed bedtime could be one of the enhancement factors for depression in children. A cross-sectional study was performed to investigate the…

Human responses to bright light of different durations.

PubMed

Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

2012-07-01

Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (<3 lux), and were then randomized for exposure to a bright light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

Comparison between an African town and a neighbouring village shows delayed, but not decreased, sleep during the early stages of urbanisation.

PubMed

Beale, Andrew D; Pedrazzoli, Mario; Gonçalves, Bruno da Silva B; Beijamini, Felipe; Duarte, Núbia E; Egan, Kieren J; Knutson, Kristen L; Schantz, Malcolm von; Roden, Laura C

2017-07-18

The well-established negative health outcomes of sleep deprivation, and the suggestion that availability of electricity may enable later bed times without compensating sleep extension in the morning, have stimulated interest in studying communities whose sleep pattern may resemble a pre-industrial state. Here, we describe sleep and activity in two neighbouring communities, one urban (Milange) and one rural (Tengua), in a region of Mozambique where urbanisation is an ongoing process. The two communities differ in the amount and timing of daily activity and of light exposure, with later bedtimes (≈1 h) associated with more evening and less daytime light exposure seen in the town of Milange. In contrast to previous reports comparing communities with and without electricity, sleep duration did not differ between Milange (7.28 h) and Tengua (7.23 h). Notably, calculated sleep quality was significantly poorer in rural Tengua than in Milange, and poor sleep quality was associated with a number of attributes more characteristic of rural areas, including more intense physical labour and less comfortable sleeping arrangements. Thus, whilst our data support the hypothesis that access to electricity delays sleep timing, the higher sleep quality in the urban population also suggests that some aspects of industrialisation are beneficial to sleep.

Sleep can reduce the testing effect: it enhances recall of restudied items but can leave recall of retrieved items unaffected.

PubMed

Bäuml, Karl-Heinz T; Holterman, Christoph; Abel, Magdalena

2014-11-01

The testing effect refers to the finding that retrieval practice in comparison to restudy of previously encoded contents can improve memory performance and reduce time-dependent forgetting. Naturally, long retention intervals include both wake and sleep delay, which can influence memory contents differently. In fact, sleep immediately after encoding can induce a mnemonic benefit, stabilizing and strengthening the encoded contents. We investigated in a series of 5 experiments whether sleep influences the testing effect. After initial study of categorized item material (Experiments 1, 2, and 4A), paired associates (Experiment 3), or educational text material (Experiment 4B), subjects were asked to restudy encoded contents or engage in active retrieval practice. A final recall test was conducted after a 12-hr delay that included diurnal wakefulness or nocturnal sleep. The results consistently showed typical testing effects after the wake delay. However, these testing effects were reduced or even eliminated after sleep, because sleep benefited recall of restudied items but left recall of retrieved items unaffected. The findings are consistent with the bifurcation model of the testing effect (Kornell, Bjork, & Garcia, 2011), according to which the distribution of memory strengths across items is shifted differentially by retrieving and restudying, with retrieval strengthening items to a much higher degree than restudy does. On the basis of this model, most of the retrieved items already fall above recall threshold in the absence of sleep, so additional sleep-induced strengthening may not improve recall of retrieved items any further. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Sleep to Implement an Intention

PubMed Central

Diekelmann, Susanne; Wilhelm, Ines; Wagner, Ullrich; Born, Jan

2013-01-01

Study Objectives: Sleep supports the consolidation of new memories. However, this effect has mainly been shown for memories of past events. Here we investigated the role of sleep for the implementation of intentions for the future. Design: Subjects were instructed on a plan that had to be executed after a delay of 2 days. After plan instruction, subjects were either allowed to sleep or stayed awake for one night (Exp. 1) or had a 3-h sleep period either during the early night (SWS-rich sleep) or late night (REM-rich sleep; Exp. 2). In both experiments, retesting took place 2 days later after one recovery night. Setting: Sleep laboratory. Patients or Participants: A total of 56 healthy young adults participated in the study. Interventions: N/A. Measurements and Results: All of the subjects who were allowed to sleep after plan instruction executed the intention 2 days later, whereas only 61% of wake subjects did so (P = 0.004; Exp. 1). Also after early SWS-rich sleep all of the subjects remembered to execute the intention, but only 55% did so after late REM-rich sleep (P = 0.015; Exp. 2). Conclusions: Sleep, especially SWS, plays an important role for the successful implementation of delayed intentions. Citation: Diekelmann S; Wilhelm I; Wagner U; Born J. Sleep to implement an intention. SLEEP 2013;36(1):149-153. PMID:23288982

Attention-deficit hyperactivity disorder symptoms add risk to circadian rhythm sleep problems in depression and anxiety.

PubMed

Bron, T I; Bijlenga, D; Kooij, J J S; Vogel, S W N; Wynchank, D; Beekman, A T F; Penninx, B W J H

2016-08-01

Comorbid ADHD symptoms may partly account for circadian rhythm disturbances in depression and anxiety disorders. Self-reported sleep characteristics of 2090 participants in the Netherlands Study of Depression and Anxiety were assessed using the Munich Chronotype Questionnaire. We defined 3 groups: healthy controls (HC), persons with lifetime depression and/or anxiety disorders (LDA), and those with both LDA and high ADHD symptoms (LDA+ADHD), using the Conner's Adult ADHD Rating Scale. Sleep characteristics were least favorable in the LDA+ADHD group. Important group differences between LDA+ADHD, LDA and HC were found for extremely late chronotype (12% vs. 5% vs. 3%; p<.001), sleep duration <6h (15% vs. 5% vs. 4%; p<.001), and for an indication of the Delayed Sleep Phase Syndrome (DSPS; 16% vs. 8% vs. 5%; p<.001). After adjustment for covariates, including depression and anxiety, presence of ADHD symptoms increased the odds ratio for late chronotype (OR=2.6; p=.003), indication of DSPS (OR=2.4; p=.002), and sleep duration <6h (OR=2.7; p=.007). ADHD conceptually overlaps with symptom presentation of depression and anxiety. We used a cross-sectional study design, and used self reported sleep characteristics. High ADHD symptoms were associated with an increased rate of circadian rhythm sleep disturbances in an already at-risk population of people with depression and/or anxiety disorders. Circadian rhythm sleep disorders, as often seen in ADHD are not entirely due to any comorbid depression and/or anxiety disorder. Adequate treatment of such sleep problems is needed and may prevent serious health conditions in the long term. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of 9-hour time zone changes on fatigue and circadian rhythms of sleep/wake and core temperature

NASA Technical Reports Server (NTRS)

Gander, P. H.; Myhre, G.; Graeber, R. C.; Andersen, H. T.; Lauber, J. K.

1985-01-01

Physiological and psychological disruptions caused by transmeridian flights may affect the ability of flight crews to meet operational demands. To study these effects, 9 Royal Norwegian Airforces P3-Orion crewmembers flew from Norway to California (-9 hr), and back (+9 hr). Rectal temperature, heart rate and wrist activity were recorded every 2 min, fatigue and mood were rated every 2 hr during the waking day, and logs were kept of sleep times and ratings. Subjects also completed 4 personality inventories. The time-zone shifts produced negative changes in mood which persisted longer after westward flights. Sleep quality (subjective and objective) and duration were slightly disrupted (more after eastward flights). The circadian rhythms of sleep/wake and temperature both completed the 9-hr delay by day 5 in California, although temperature adjusted more slowly. The size of the delay shift was significantly correlated with scores on extraversion and achievement need personality scales. Response to the 9-hr advance were more variable. One subject exhibited a 15-hr delay in his temperature rhythm, and an atypical sleep/nap pattern. On average, the sleep/wake cycle (but not the temperature rhythm), completed the 9-hr advance by the end of the study. Both rhythms adapted more slowly after the eastward flight.

Energy conservation in ad hoc multimedia networks using traffic-shaping mechanisms

NASA Astrophysics Data System (ADS)

Chandra, Surendar

2003-12-01

In this work, we explore network traffic shaping mechanisms that deliver packets at pre-determined intervals; allowing the network interface to transition to a lower power consuming sleep state. We focus our efforts on commodity devices, IEEE 802.11b ad hoc mode and popular streaming formats. We argue that factors such as the lack of scheduling clock phase synchronization among the participants and scheduling delays introduced by back ground tasks affect the potential energy savings. Increasing the periodic transmission delays to transmit data infrequently can offset some of these effects at the expense of flooding the wireless channel for longer periods of time; potentially increasing the time to acquire the channel for non-multimedia traffic. Buffering mechanisms built into media browsers can mitigate the effects of these added delays from being mis-interpreted as network congestion. We show that practical implementations of such traffic shaping mechanisms can offer significant energy savings.

Circadian phase assessment by ambulatory monitoring in humans: correlation with dim light melatonin onset.

PubMed

Bonmati-Carrion, M A; Middleton, B; Revell, V; Skene, D J; Rol, M A; Madrid, J A

2014-02-01

The increased prevalence of circadian disruptions due to abnormal coupling between internal and external time makes the detection of circadian phase in humans by ambulatory recordings a compelling need. Here, we propose an accurate practical procedure to estimate circadian phase with the least possible burden for the subject, that is, without the restraints of a constant routine protocol or laboratory techniques such as melatonin quantification, both of which are standard procedures. In this validation study, subjects (N = 13) wore ambulatory monitoring devices, kept daily sleep diaries and went about their daily routine for 10 days. The devices measured skin temperature at wrist level (WT), motor activity and body position on the arm, and light exposure by means of a sensor placed on the chest. Dim light melatonin onset (DLMO) was used to compare and evaluate the accuracy of the ambulatory variables in assessing circadian phase. An evening increase in WT: WTOnset (WTOn) and "WT increase onset" (WTiO) was found to anticipate the evening increase in melatonin, while decreases in motor activity (Activity Offset or AcOff), body position (Position Offset (POff)), integrative TAP (a combination of WT, activity and body position) (TAPOffset or TAPOff) and an increase in declared sleep propensity were phase delayed with respect to DLMO. The phase markers obtained from subjective sleep (R = 0.811), WT (R = 0.756) and the composite variable TAP (R = 0.720) were highly and significantly correlated with DLMO. The findings strongly support a new method to calculate circadian phase based on WT (WTiO) that accurately predicts and shows a temporal association with DLMO. WTiO is especially recommended due to its simplicity and applicability to clinical use under conditions where knowing endogenous circadian phase is important, such as in cancer chronotherapy and light therapy.

Insomnia, Nightmares, and Chronotype as Markers of Risk for Severe Mental Illness: Results from a Student Population.

PubMed

Sheaves, Bryony; Porcheret, Kate; Tsanas, Athanasios; Espie, Colin A; Foster, Russell G; Freeman, Daniel; Harrison, Paul J; Wulff, Katharina; Goodwin, Guy M

2016-01-01

To group participants according to markers of risk for severe mental illness based on subsyndromal symptoms reported in early adulthood and evaluate attributes of sleep across these risk categories. An online survey of sleep and psychiatric symptomatology (The Oxford Sleep Survey) was administered to students at one United Kingdom university. 1403 students (undergraduate and postgraduate) completed the survey. The median age was 21 (interquartile range = 20-23) and 55.60% were female. The cross-sectional data were used to cluster participants based on dimensional measures of psychiatric symptoms (hallucinations, paranoia, depression, anxiety, and (hypo)mania). High, medium, and low symptom groups were compared across sleep parameters: insomnia symptoms, nightmares, chronotype, and social jet lag. Insomnia symptoms, nightmares frequency, and nightmare-related distress increased in a dose-response manner with higher reported subsyndromal psychiatric symptoms (low, medium, and high). The high-risk group exhibited a later chronotype (mid sleep point for free days) than the medium- or low-risk group. The majority of participants (71.7%) in the high-risk group screened positive for insomnia and the median nightmare frequency was two per 14 days (moderately severe pathology). Insomnia, nightmares, and circadian phase delay are associated with increased subsyndromal psychiatric symptoms in young people. Each is a treatable sleep disorder and might be a target for early intervention to modify the subsequent progression of psychiatric disorder. © 2016 Associated Professional Sleep Societies, LLC.

Modeling the effects of caffeine on the sleep/ wake cycle.

PubMed

Daniello, Allison; Fievisohn, Elizabeth; Gregory, T Stan

2012-01-01

Caffeine is present in many products consumed daily, including coffee, soda, and chocolate, and is known to delay the onset of sleepiness and cause sleep disturbances. It is an adenosine antagonist, inhibiting some hormones that promote sleep, and therefore promoting wakefulness. This paper proposes a model to incorporate the effects of caffeine on the sleep/wake cycle. The “flip-flop” model was used to model the sleep cycle, where switching between a sleep state and a wake state was nearly instantaneous. Sleep patterns were modeled based on the circadian rhythm and homeostatic drive, as was done by Rempe et al. (2010). The model demonstrated how the homeostatic drive and circadian rhythm interact to cause sleep and wakefulness. The effects of caffeine were incorporated to have a masking effect on the homeostatic drive, promoting wakefulness. Preliminary results showed that caffeine intake late in the evening caused the switch from wake to sleep to occur later than if no caffeine was present in the system. Additionally, the switch from wake to sleep was increasingly delayed with increased caffeine intake at the same time. This model is not yet validated, though potential studies for validation are proposed. This model presents an interesting method for incorporating the effects of caffeine on the sleep/wake cycle.

Associations Between Sleep-Wake Consolidation and Language Development in Early Childhood: A Longitudinal Twin Study

PubMed Central

Dionne, Ginette; Touchette, Evelyne; Forget-Dubois, Nadine; Petit, Dominique; Tremblay, Richard E.; Montplaisir, Jacques Y.; Boivin, Michel

2011-01-01

Study Objectives: The objectives were (1) to assess associations between sleep consolidation at 6, 18 and 30 months and language skills at 18, 30, and 60 months; and (2) to investigate the genetic/environmental etiology of these associations. Design: Longitudinal study of a population-based twin cohort. Participants: 1029 twins from the Quebec Newborn Twin Study. Measurements and Results: Sleep consolidation was derived from parental reports of day/night consecutive sleeping durations. Language skills were assessed with the MacArthur Communicative Development Inventory at 18 and 30 months and the Peabody Picture Vocabulary Test at 60 months. The day/night sleep ratio decreased significantly from 6 to 30 months. The 6- and 18-month ratios were negatively correlated with subsequent language skills. Children with language delays at 60 months had less mature sleep consolidation at both 6 and 18 months than children without delays and those with transient early delays. Genetic and regression analyses revealed that the sleep ratio at 6 months was highly heritable (64%) and predicted 18-month (B = −0.06) and 30-month language (B = −0.11) mainly through additive genetic influences (RGs = 0.32 and 0.33, respectively). By contrast, the sleep ratio at 18 months was mainly due to shared environment influences (58%) and predicted 60-month language (B = −0.08) through shared environment influences (RCs = 0.24). Conclusions: Poor sleep consolidation during the first 2 years of life may be a risk factor for language learning, whereas good sleep consolidation may foster language learning through successive genetic and environmental influences. Citation: Dionne G; Touchette E; Forget-Dubois N; Petit D; Tremblay RE; Montplaisir JY; Boivin M. Associations between sleep-wake consolidation and language development in early childhood: a longitudinal twin study. SLEEP 2011;34(8):987-995. PMID:21804661

Disturbed EEG sleep, paranoid cognition and somatic symptoms identify veterans with post-traumatic stress disorder

PubMed Central

Rothman, Lorne; Kleinman, Robert; Rhind, Shawn G.; Richardson, J. Donald

2016-01-01

Background Chronic post-traumatic stress disorder (PTSD) behavioural symptoms and medically unexplainable somatic symptoms are reported to occur following the stressful experience of military combatants in war zones. Aims To determine the contribution of disordered EEG sleep physiology in those military combatants who have unexplainable physical symptoms and PTSD behavioural difficulties following war-zone exposure. Method This case-controlled study compared 59 veterans with chronic sleep disturbance with 39 veterans with DSM-IV and clinician-administered PTSD Scale diagnosed PTSD who were unresponsive to pharmacological and psychological treatments. All had standardised EEG polysomnography, computerised sleep EEG cyclical alternating pattern (CAP) as a measure of sleep stability, self-ratings of combat exposure, paranoid cognition and hostility subscales of Symptom Checklist-90, Beck Depression Inventory and the Wahler Physical Symptom Inventory. Statistical group comparisons employed linear models, logistic regression and chi-square automatic interaction detection (CHAID)-like decision trees. Results Veterans with PTSD were more likely than those without PTSD to show disturbances in non-rapid eye movement (REM) and REM sleep including delayed sleep onset, less efficient EEG sleep, less stage 4 (deep) non-REM sleep, reduced REM and delayed onset to REM. There were no group differences in the prevalence of obstructive sleep apnoeas/hypopnoeas and periodic leg movements, but sleep-disturbed, non-PTSD military had more EEG CAP sleep instability. Rank order determinants for the diagnosis of PTSD comprise paranoid thinking, onset to REM sleep, combat history and somatic symptoms. Decision-tree analysis showed that a specific military event (combat), delayed onset to REM sleep, paranoid thinking and medically unexplainable somatic pain and fatigue characterise chronic PTSD. More PTSD veterans reported domestic and social misbehaviour. Conclusions Military combat, disturbed REM/non-REM EEG sleep, paranoid ideation and medically unexplained chronic musculoskeletal pain and fatigue are key factors in determining PTSD disability following war-zone exposure. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:29018561

Organizational justice and sleeping problems: The Whitehall II study.

PubMed

Elovainio, Marko; Ferrie, Jane E; Gimeno, David; De Vogli, Roberto; Shipley, Martin; Brunner, Eric J; Kumari, Meena; Vahtera, Jussi; Marmot, Michael G; Kivimäki, Mika

2009-04-01

To test the hypothesis that organizational injustice contributes to sleeping problems. Poor sleep quality can be a marker of prolonged emotional stress and has been shown to have serious effects on the immune system and metabolism. Data were from the prospective Whitehall II study of white-collar British civil servants (3143 women and 6895 men, aged 35-55 years at baseline). Age, employment grade, health behaviors, and depressive symptoms were measured at Phase 1 (1985-1988) and baseline sleeping problems were assessed at Phase 2 (1989-1990). Organizational justice was assessed twice, at Phases 1 and 2. The outcome was mean of sleeping problems during Phases 5 (1997-1999) and 7 (2003-2004). In men, low organizational justice at Phase 1 and Phase 2 were associated with overall sleeping problems, sleep maintenance problems, sleep onset problems, and nonrefreshing sleep at Phases 5 and 7. In women, a significant association was observed between low organizational justice and overall sleeping problems and sleep onset problems. These associations were robust to adjustments for age, employment grade, health behaviors, job strain, depressive symptoms, and sleeping problems at baseline. This study shows that perceived unfair treatment at workplace is associated with increased risk of poor sleep quality in men and women, one potential mechanism through which justice at work may affect health.

School Start Time and Adolescent Sleep Patterns: Results From the US National Comorbidity Survey—Adolescent Supplement

PubMed Central

Paksarian, Diana; Rudolph, Kara E.

2015-01-01

Objectives. We estimated associations between school start time and adolescent weeknight bedtime, weeknight sleep duration, and weekend compensatory sleep and assessed whether associations differ by age, sex, or urbanicity. Methods. We used a subsample of a nationally representative, cross-sectional survey of 7308 students aged 13 to 18 years attending 245 schools to estimate associations of school start time, reported by school principals, with weeknight bedtime and sleep duration and weekend compensatory sleep, reported during adolescent face-to-face interviews. Results. Start time was positively associated with weeknight bedtime. Associations between start time and weeknight sleep duration were nonlinear and were strongest for start times of 8:00 am and earlier. Associations differed by sex and urbanicity, with the strongest association among boys in major metropolitan counties. Start time was negatively associated with sleep duration among boys in nonurban counties. Start time was not associated with weekend compensatory sleep. Conclusions. Positive overall associations between school start time and adolescent sleep duration at the national level support recent policy recommendations for delaying school start times. However, the impact of start time delays may differ by sex and urbanicity. PMID:25973803

Setting Adolescents up for Success: Promoting a Policy to Delay High School Start Times

ERIC Educational Resources Information Center

Barnes, Margaux; Davis, Krista; Mancini, Mackenzie; Ruffin, Jasmine; Simpson, Tina; Casazza, Krista

2016-01-01

Background: A unique biological shift in sleep cycles occurs during adolescence causing later sleep and wake times. This shift is not matched by a concurrent modification in school start times, resulting in sleep curtailment for a large majority of adolescents. Chronic inadequate sleep is associated with poor academic performance including…

Genetic Variation in Melatonin Pathway Enzymes in Children with Autism Spectrum Disorder and Comorbid Sleep Onset Delay

ERIC Educational Resources Information Center

Veatch, Olivia J.; Pendergast, Julie S.; Allen, Melissa J.; Leu, Roberta M.; Johnson, Carl Hirschie; Elsea, Sarah H.; Malow, Beth A.

2015-01-01

Sleep disruption is common in individuals with autism spectrum disorder (ASD). Genes whose products regulate endogenous melatonin modify sleep patterns and have been implicated in ASD. Genetic factors likely contribute to comorbid expression of sleep disorders in ASD. We studied a clinically unique ASD subgroup, consisting solely of children with…

Parent-Based Sleep Education for Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Malow, Beth A.; Adkins, Karen W.; Reynolds, Ann; Weiss, Shelly K.; Loh, Alvin; Fawkes, Diane; Katz, Terry; Goldman, Suzanne E.; Madduri, Niru; Hundley, Rachel; Clemons, Traci

2014-01-01

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent…

Executive function mediates prospective relationships between sleep duration and sedentary behavior in children.

PubMed

Warren, Christopher; Riggs, Nathaniel; Pentz, Mary Ann

2016-10-01

Childhood sedentary behavior has been linked to increased obesity risk. Prior work has identified associations between sedentary behavior, executive function (EF), and sleep. This study tested the hypothesis that reduced sleep duration may adversely impact EF and lead to increased childhood sedentary behavior. Southern California schoolchildren participating in the school-based health promotion program Pathways to Health (N=709) were assessed annually from 4th through 6th grades (2010-2013) on self-report measures of sedentary behavior, sleep duration, and executive function. A series of path models were specified treating average nightly sleep duration and weekend wake/bed-time shift at 4th grade as predictors of 6th grade sedentary behavior. Four EF subdomains were tested as potential mediators of longitudinal associations at 5th grade. Significant associations between average nightly sleep duration, EF and sedentary behavior were identified (p<0.05), adjusting for participant gender, physical activity, SES, ethnicity, program group assignment, and the presence/absence of parental screen time rules. Fifth grade overall EF (p<0.05)-and in particular the subdomains of inhibitory control (p<0.05) and organization of materials (p<0.01)-significantly mediated the relationship between 4th grade sleep duration and 6th grade sedentary behavior (p<0.05). Furthermore, delay of weekend bed- or wake-times relative to weekdays was prospectively associated with decreased overall EF (p<0.05), but not increased sedentary behavior (p=0.35 for bed-time delay; p=0.64 for wake-time delay), irrespective of average nightly sleep duration. Findings suggest that sleep promotion efforts may reduce children's sedentary behavior both directly and indirectly through changes in EF. Copyright © 2016 Elsevier Inc. All rights reserved.

Executive function mediates prospective relationships between sleep duration and sedentary behavior in children

PubMed Central

Warren, Christopher; Riggs, Nathaniel; Pentz, Mary Ann

2016-01-01

Childhood sedentary behavior has been linked to increased obesity risk. Prior work has identified associations between sedentary behavior, executive function (EF), and sleep. This study tested the hypothesis that reduced sleep duration may adversely impact EF and lead to increased childhood sedentary behavior. Southern California schoolchildren participating in the school-based health promotion program Pathways to Health (N = 709) were assessed annually from 4th through 6th grades (2010–2013) on self-report measures of sedentary behavior, sleep duration, and executive function. A series of path models were specified treating average nightly sleep duration and weekend wake/bed-time shift at 4th grade as predictors of 6th grade sedentary behavior. Four EF subdomains were tested as potential mediators of longitudinal associations at 5th grade. Significant associations between average nightly sleep duration, EF and sedentary behavior were identified (p < 0.05), adjusting for participant gender, physical activity, SES, ethnicity, program group assignment, and the presence/absence of parental screen time rules. Fifth grade overall EF (p < 0.05)—and in particular the subdomains of inhibitory control (p < 0.05) and organization of materials (p < 0.01)—significantly mediated the relationship between 4th grade sleep duration and 6th grade sedentary behavior (p < 0.05). Furthermore, delay of weekend bed- or wake-times relative to weekdays was prospectively associated with decreased overall EF (p < 0.05), but not increased sedentary behavior (p = 0.35 for bed-time delay; p = 0.64 for wake-time delay), irrespective of average nightly sleep duration. Findings suggest that sleep promotion efforts may reduce children’s sedentary behavior both directly and indirectly through changes in EF. PMID:27477059

Work stressors, perseverative cognition and objective sleep quality: a longitudinal study among Dutch Helicopter Emergency Medical Service (HEMS) Pilots.

PubMed

Radstaak, Mirjam; Geurts, Sabine A E; Beckers, Debby G J; Brosschot, Jos F; Kompier, Michiel A J

2014-01-01

This longitudinal study examined the associations between work stressors, perseverative cognition and subjective and objective sleep quality. We hypothesized work stressors to be associated with (i) poor nocturnal sleep quality and (ii) higher levels of perseverative cognition during a free evening. We further hypothesized (iii) perseverative cognition to be associated with poor nocturnal sleep quality and (iv) the association between work stressors and sleep quality to be mediated by perseverative cognition. The participants were 24 pilots working for the Dutch Helicopter Emergency Medical Service (HEMS). They completed six questionnaires: at the end of three consecutive day shifts and each morning following the shifts. The questionnaires addressed work stressors (workload, distressing shifts and work-related conflicts), subjective sleep quality and perseverative cognition. Participants wore actigraphs to assess sleep onset latency, total sleep time and number of awakenings. Correlation analysis revealed that (i) distressing shifts were related to delayed sleep onset (r=0.50, p=0.026) and that workload was related to impaired sleep quality (e.g., subjective sleep quality: r=-0.42, p=0.044). Moreover, (ii) distressing shifts were positively related to perseverative cognition (r=0.62, p=0.002), (iii) perseverative cognition delayed sleep onset (r=0.74, p<0.001) and (iv) mediated the association between distressing shifts and sleep onset latency. Perseverative cognition may be an explanatory mechanism in the association between work stressors and poor sleep.

Emotional trait and memory associates of sleep timing and quality

PubMed Central

Pace-Schott, Edward F.; Rubin, Zoe S.; Tracy, Lauren E.; Spencer, Rebecca M.C.; Orr, Scott P.; Verga, Patrick W.

2015-01-01

Poor ability to remember the extinction of conditioned fear, elevated trait anxiety, and delayed or disrupted nocturnal sleep are reported in anxiety disorders. The current study examines the interrelationship of these factors in healthy young-adult males. Skin- conductance response was conditioned to two differently colored lamps. One color but not the other was then extinguished. After varying delays, both colors were presented to determine extinction recall and generalization. Questionnaires measured sleep quality, morningness - eveningness, neuroticism and trait anxiety. A subset produced a mean 7.0 nights of actigraphy and sleep diaries. Median split of mean sleep midpoint defined early-and late-”sleep timers”. Extinction was more rapidly learned in the morning than evening only in early-timers, who also better generalized extinction recall. Extinction recall was greater with higher sleep efficiency. Sleep efficiency and morningness were negatively associated with neuroticism and anxiety. However, neuroticism and anxiety did not predict extinction learning, recall or generalization. Therefore, neuroticism/anxiety and deficient fear extinction, although both associated with poor quality and late timing of sleep, are not directly associated with each other. Elevated trait anxiety, in addition to predisposing directly to anxiety disorders, may thus also indirectly promote such disorders by impairing sleep and, consequently, extinction memory. PMID:26257092

Emotional trait and memory associates of sleep timing and quality.

PubMed

Pace-Schott, Edward F; Rubin, Zoe S; Tracy, Lauren E; Spencer, Rebecca M C; Orr, Scott P; Verga, Patrick W

2015-10-30

Poor ability to remember the extinction of conditioned fear, elevated trait anxiety, and delayed or disrupted nocturnal sleep are reported in anxiety disorders. The current study examines the interrelationship of these factors in healthy young-adult males. Skin-conductance response was conditioned to two differently colored lamps. One color but not the other was then extinguished. After varying delays, both colors were presented to determine extinction recall and generalization. Questionnaires measured sleep quality, morningness-eveningness, neuroticism and trait anxiety. A subset produced a mean 7.0 nights of actigraphy and sleep diaries. Median split of mean sleep midpoint defined early- and late-"sleep timers". Extinction was more rapidly learned in the morning than evening only in early timers who also better generalized extinction recall. Extinction recall was greater with higher sleep efficiency. Sleep efficiency and morningness were negatively associated with neuroticism and anxiety. However, neuroticism and anxiety did not predict extinction learning, recall or generalization. Therefore, neuroticism/anxiety and deficient fear extinction, although both associated with poor quality and late timing of sleep, are not directly associated with each other. Elevated trait anxiety, in addition to predisposing directly to anxiety disorders, may thus also indirectly promote such disorders by impairing sleep and, consequently, extinction memory. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Buying time: a rationale for examining the use of circadian rhythm and sleep interventions to delay progression of mild cognitive impairment to Alzheimer's disease.

PubMed

Landry, Glenn J; Liu-Ambrose, Teresa

2014-01-01

As of 2010, the worldwide economic impact of dementia was estimated at $604 billion USD; and without discovery of a cure or effective interventions to delay disease progression, dementia's annual global economic impact is expected to surpass $1 trillion USD as early as 2030. Alzheimer's disease (AD) is the leading cause of dementia accounting for over 75% of all cases. Toxic accumulation of amyloid beta (Aβ), either by overproduction or some clearance failure, is thought to be an underlying mechanism of the neuronal cell death characteristic of AD-though this amyloid hypothesis has been increasingly challenged in recent years. A compelling alternative hypothesis points to chronic neuroinflammation as a common root in late-life degenerative diseases including AD. Apolipoprotein-E (APOE) genotype is the strongest genetic risk factor for AD: APOE-ε4 is proinflammatory and individuals with this genotype accumulate more Aβ, are at high risk of developing AD, and almost half of all AD patients have at least one ε4 allele. Recent studies suggest a bidirectional relationship exists between sleep and AD pathology. Sleep may play an important role in Aβ clearance, and getting good quality sleep vs. poor quality sleep might reduce the AD risk associated with neuroinflammation and the ε4 allele. Taken together, these findings are particularly important given the sleep disruptions commonly associated with AD and the increased burden disrupted sleep poses for AD caregivers. The current review aims to: (1) identify individuals at high risk for dementia who may benefit most from sleep interventions; (2) explore the role poor sleep quality plays in exacerbating AD type dementia; (3) examine the science of sleep interventions to date; and (4) provide a road map in pursuit of comprehensive sleep interventions, specifically targeted to promote cognitive function and delay progression of dementia.

Buying time: a rationale for examining the use of circadian rhythm and sleep interventions to delay progression of mild cognitive impairment to Alzheimer’s disease

PubMed Central

Landry, Glenn J.; Liu-Ambrose, Teresa

2014-01-01

As of 2010, the worldwide economic impact of dementia was estimated at $604 billion USD; and without discovery of a cure or effective interventions to delay disease progression, dementia’s annual global economic impact is expected to surpass $1 trillion USD as early as 2030. Alzheimer’s disease (AD) is the leading cause of dementia accounting for over 75% of all cases. Toxic accumulation of amyloid beta (Aβ), either by overproduction or some clearance failure, is thought to be an underlying mechanism of the neuronal cell death characteristic of AD—though this amyloid hypothesis has been increasingly challenged in recent years. A compelling alternative hypothesis points to chronic neuroinflammation as a common root in late-life degenerative diseases including AD. Apolipoprotein-E (APOE) genotype is the strongest genetic risk factor for AD: APOE-ε4 is proinflammatory and individuals with this genotype accumulate more Aβ, are at high risk of developing AD, and almost half of all AD patients have at least one ε4 allele. Recent studies suggest a bidirectional relationship exists between sleep and AD pathology. Sleep may play an important role in Aβ clearance, and getting good quality sleep vs. poor quality sleep might reduce the AD risk associated with neuroinflammation and the ε4 allele. Taken together, these findings are particularly important given the sleep disruptions commonly associated with AD and the increased burden disrupted sleep poses for AD caregivers. The current review aims to: (1) identify individuals at high risk for dementia who may benefit most from sleep interventions; (2) explore the role poor sleep quality plays in exacerbating AD type dementia; (3) examine the science of sleep interventions to date; and (4) provide a road map in pursuit of comprehensive sleep interventions, specifically targeted to promote cognitive function and delay progression of dementia. PMID:25538616

Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study.

PubMed

van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

2017-01-01

Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

REM sleep and emotional face memory in typically-developing children and children with autism.

PubMed

Tessier, Sophie; Lambert, Andréane; Scherzer, Peter; Jemel, Boutheina; Godbout, Roger

2015-09-01

Relationship between REM sleep and memory was assessed in 13 neurotypical and 13 children with Autistic Spectrum Disorder (ASD). A neutral/positive/negative face recognition task was administered the evening before (learning and immediate recognition) and the morning after (delayed recognition) sleep. The number of rapid eye movements (REMs), beta and theta EEG activity over the visual areas were measured during REM sleep. Compared to neurotypical children, children with ASD showed more theta activity and longer reaction time (RT) for correct responses in delayed recognition of neutral faces. Both groups showed a positive correlation between sleep and performance but different patterns emerged: in neurotypical children, accuracy for recalling neutral faces and overall RT improvement overnight was correlated with EEG activity and REMs; in children with ASD, overnight RT improvement for positive and negative faces correlated with theta and beta activity, respectively. These results suggest that neurotypical and children with ASD use different sleep-related brain networks to process faces. Copyright © 2015 Elsevier B.V. All rights reserved.

Maternal Sensitivity Predicts Fewer Sleep Problems at Early Adolescence for Toddlers with Negative Emotionality: A Case of Differential Susceptibility.

PubMed

Conway, Anne; Modrek, Anahid; Gorroochurn, Prakash

2018-02-01

Theory underscores the importance of parenting in sleep development, but few studies have examined whether links vary by temperament. To address this gap, we tested whether potential links between early maternal sensitivity and early adolescent sleep problems varied by child negative emotionality and delay of gratification. Using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 820), we found that high maternal sensitivity predicted fewer bedtime problems and longer sleep duration at 6th grade for toddlers with high negative emotionality, whereas low maternal sensitivity predicted the reverse. No differences were observed for low negative emotionality. Moreover, delay of gratification predicted fewer bedtime problems at 6th grade, but did not moderate associations between maternal sensitivity, negative emotionality, and sleep. Findings demonstrate that high, but not low, negative emotionality renders toddlers differentially susceptible and receptive to maternal sensitivity in relation to sleep.

Morningness-eveningness and daytime functioning in university students: the mediating role of sleep characteristics.

PubMed

Bakotic, Marija; Radosevic-Vidacek, Biserka; Koscec Bjelajac, Adrijana

2017-04-01

The aim of this study was to explore the mediating role of sleep characteristics in the relationship between morningness-eveningness and three different aspects of daytime functioning: daytime sleepiness, depressive mood and substance use in university students. A multiple mediator model was proposed with sleep debt, poor sleep quality and bedtime delay at weekends as parallel mediators in these relationships. We analysed the data of 1052 university students aged 18-25 years who completed a modified version of the School Sleep Habits Survey, which included questions on sleep and the Composite Scale of Morningness, Sleepiness Scale, Depressive Mood Scale and Substance Use Scale. Students with more pronounced eveningness reported greater daytime sleepiness, greater depressive mood and more frequent substance use, as well as greater sleep debt, poorer sleep quality and greater bedtime delay at weekends. Mediation analyses indicated that morningness-eveningness affected daytime sleepiness and substance use both directly and indirectly through all proposed sleep-related mediators. However, the effect of morningness-eveningness on depressive mood was entirely indirect and was accounted for more by poor sleep than by sleep debt or bedtime irregularity. In conclusion, there are multiple possible mechanisms through which morningness-eveningness affects daytime functioning in university students, and sleep characteristics are a significant mechanism. Sleep debt, poor sleep quality and bedtime irregularity can, to a significant extent, explain the feeling of daytime sleepiness and greater substance use in students with eveningness preferences. However, more depressed mood in the evening-orientated students is primarily a consequence of their poor sleep quality. © 2016 European Sleep Research Society.

Exploring the daily activities associated with delayed bedtime of Japanese university students.

PubMed

Asaoka, Shoichi; Komada, Yoko; Fukuda, Kazuhiko; Sugiura, Tatsuki; Inoue, Yuichi; Yamazaki, Katuo

2010-07-01

University students show delayed sleep-wake patterns, i.e., later bed- and rise-times, and this pattern is known to be associated with various malfunctions. There may be a variety of daily activities associated with their delayed sleep patterns, such as watching TV. However, it is unclear to what extent each activity possesses an impact on their sleep patterns. The purpose of this study was to determine the daily activities associated with delayed bedtime in Japanese university students who live with or without their families. Three hundred and thirty-one participants were required to record the timing and duration of their sleep and daily activities, and the data from the 275 students (160 men and 115 women; 19.01 +/- 1.66 years) who completely filled forms were used for analysis. The results of multiple regression analyses suggested that interpersonal communication late at night is one of the major factors leading to the delayed bedtime of students living away from home. Among those living with their families, indoor activities such as watching TV and using the Internet were related to their delayed bedtimes. Attending classes and having a morning meal were related to the earlier bedtimes of the students living away from home, but there were no activities associated with those of the students living with their families. These results suggest that ensuring attendance at morning classes and having appropriate mealtimes, as well as restricting the use of visual media and socializing activities at night, are necessary for preventing late bedtimes in university students.

Sleep deprivation affects extinction but not acquisition memory in honeybees.

PubMed

Hussaini, Syed Abid; Bogusch, Lisa; Landgraf, Tim; Menzel, Randolf

2009-11-01

Sleep-like behavior has been studied in honeybees before, but the relationship between sleep and memory formation has not been explored. Here we describe a new approach to address the question if sleep in bees, like in other animals, improves memory consolidation. Restrained bees were observed by a web camera, and their antennal activities were used as indicators of sleep. We found that the bees sleep more during the dark phase of the day compared with the light phase. Sleep phases were characterized by two distinct patterns of antennal activities: symmetrical activity, more prominent during the dark phase; and asymmetrical activity, more common during the light phase. Sleep-deprived bees showed rebound the following day, confirming effective deprivation of sleep. After appetitive conditioning of the bees to various olfactory stimuli, we observed their sleep. Bees conditioned to odor with sugar reward showed lesser sleep compared with bees that were exposed to either reward alone or air alone. Next, we asked whether sleep deprivation affects memory consolidation. While sleep deprivation had no effect on retention scores after odor acquisition, retention for extinction learning was significantly reduced, indicating that consolidation of extinction memory but not acquisition memory was affected by sleep deprivation.

Biological Rhythms During Residence in Polar Regions

PubMed Central

2012-01-01

At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with “normal” working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within a week, in contrast to temperate zones where complete adaptation rarely occurs. A similar situation occurs on high-latitude North Sea oil installations, especially when working 18:00–06:00 h. Lack of conflicting light exposure (and “social obligations”) is the probable explanation. Many have problems returning to day work, showing circadian desynchrony. Timed light treatment again has helped to restore normal phase/sleep in a small number of people. Postprandial response to meals is compromised during periods of desynchrony with evidence of insulin resistance and elevated triglycerides, risk factors for heart disease. Only small numbers of subjects have been studied intensively in polar regions; however, these observations suggest that suboptimal light conditions are deleterious to health. They apply equally to people living in temperate zones with insufficient light exposure. PMID:22497433

In vivo size and shape measurement of the human upper airway using endoscopic longrange optical coherence tomography

NASA Astrophysics Data System (ADS)

Armstrong, Julian J.; Leigh, Matthew S.; Walton, Ian D.; Zvyagin, Andrei V.; Alexandrov, Sergey A.; Schwer, Stefan; Sampson, David D.; Hillman, David R.; Eastwood, Peter R.

2003-07-01

We describe a long-range optical coherence tomography system for size and shape measurement of large hollow organs in the human body. The system employs a frequency-domain optical delay line of a configuration that enables the combination of high-speed operation with long scan range. We compare the achievable maximum delay of several delay line configurations, and identify the configurations with the greatest delay range. We demonstrate the use of one such long-range delay line in a catheter-based optical coherence tomography system and present profiles of the human upper airway and esophagus in vivo with a radial scan range of 26 millimeters. Such quantitative upper airway profiling should prove valuable in investigating the pathophysiology of airway collapse during sleep (obstructive sleep apnea).

Usefulness of a Nocturnal SOREMP for Diagnosing Narcolepsy with Cataplexy in a Pediatric Population

PubMed Central

Reiter, Joel; Katz, Eliot; Scammell, Thomas E.; Maski, Kiran

2015-01-01

Study Objectives: We investigated the diagnostic accuracy of a nocturnal sleep onset rapid eye movement sleep period (nSOREMP) for the identification of narcolepsy with cataplexy (N+C) among children and adolescents referred to the sleep laboratory for an overnight polysomnography (PSG) and multiple sleep latency test (MSLT). Design: Retrospective chart review of sleep clinic notes and PSG and MSLT reports. Setting: Boston Children's Hospital sleep laboratory and outpatient clinics. Patients: All patients 6–18 y old, referred for consecutive PSG and MSLT for the evaluation of central hypersomnias, between January 2005 and January 2014. Measurements and Results: We analyzed the records of 148 patients and established diagnostic categories using the International Classification of Sleep Disorders, 2nd Edition. Patient diagnoses included narcolepsy with cataplexy (28.4%), narcolepsy without cataplexy (8.1%), other hypersomnia conditions (9.5%), delayed sleep phase syndrome (12.2%), behaviorally induced insufficient sleep syndrome (4.1%), other sleep disorders (obstructive sleep apnea, periodic limb movements of sleep; 6.8%), isolated cataplexy (2%), and various diagnoses (29.1%). There were 54.8% of the N+C patients who had an nSOREMP, but only 2.4% of all other patients had an nSOREMP. The specificity of an nSOREMP for detection of N+C was high at 97.3% (95% confidence interval [CI]: 92.2–99.4%), but the sensitivity was moderate at 54.8% (95% CI: 38.7–70.2%). Overall, the positive predictive value of an nSOREMP for the diagnosis of N+C was 88.5% (95% CI: 69.8–97.4%). Conclusions: In children, the presence of an nocturnal sleep onset rapid eye movement sleep period is highly suggestive of narcolepsy with cataplexy and provides further evidence of rapid eye movement sleep dysregulation in this condition. Citation: Reiter J, Katz E, Scammell TE, Maski K. Usefulness of a nocturnal SOREMP for diagnosing narcolepsy with cataplexy in a pediatric population. SLEEP 2015;38(6):859–865. PMID:25325489

Circadian Entrainment, Sleep-Wake Regulation and Neurobehavioral Performance During Extended Duration Space Flight

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.

1999-01-01

Long-duration manned space flight requires crew members to maintain a high level of cognitive performance and vigilance while operating and monitoring sophisticated instrumentation. However, the reduction in the strength of environmental synchronizers in the space environment leads to misalignment of circadian phase among crew members, coupled with restricted time available to sleep, results in sleep deprivation and consequent deterioration of neurobehavioral function. Crew members are provided, and presently use, long-acting benzodiazepine hypnotics on board the current, relatively brief space shuttle missions to counteract such sleep disruption, a situation that is only likely to worsen during extended duration missions. Given the known carry-over effects of such compounds on daytime performance, together with the reduction in emergency readiness associated with their use at night, NASA has recognized the need to develop effective but safe countermeasures to allow crew members to obtain an adequate amount of sleep. Over the past eight years, we have successfully implemented a new technology for shuttle crew members involving bright light exposure during the pre-launch period to facilitate adaptation of the circadian timing system to the inversions of the sleep-wake schedule often required during dual shift missions. However for long duration space station missions it will be necessary to develop effective and attainable countermeasures that can be used chronically to optimize circadian entrainment. Our current research effort is to study the effects of light-dark cycles with reduced zeitgeber strength, such as are anticipated during long-duration space flight, on the entrainment of the endogenous circadian timing system and to study the effects of a countermeasure that consists of scheduled brief exposures to bright light on the human circadian timing system. The proposed studies are designed to address the following Specific Aims: (1) test the hypothesis that synchronization of the human circadian pacemaker will be disturbed in men and women by the reduction in LD cycle strength. (2) test the hypothesis that this disturbed circadian synchronization will result in the secretion of the sleep-promoting hormone melatonin during the waking day, disturbed sleep, reduced growth hormone secretion, and impaired performance and daytime alertness; (3) as a countermeasure, test the hypothesis that brief daily exposures to bright light (10,000 lux) will reestablish normal entrained circadian phase, resulting in improved sleep consolidation, normalized sleep structure and endogenous growth hormone secretion and enhanced daytime performance. To date, we have carried out twelve experiments to address Hypotheses I and 2 and data analyses are in progress. The results of the current research may have important implications for the treatment of circadian rhythm sleep disorders, such as delayed sleep phase syndrome and shift-work dyssomnia, which are anticipated to have a high incidence and prevalence during extended duration space flight such as planned for the International Space Station and manned missions to Mars.

The relationship between sleep and cognitive function in patients with prediabetes and type 2 diabetes.

PubMed

Saetung, Sunee; Nimitphong, Hataikarn; Siwasaranond, Nantaporn; Sumritsopak, Rungtip; Jindahra, Panitha; Krairit, Orapitchaya; Thakkinstian, Ammarin; Anothaisintawee, Thunyarat; Reutrakul, Sirimon

2018-06-06

Diabetes is linked to cognitive impairment. Sleep plays a role in memory consolidation. Sleep disturbances, commonly found in patients with diabetes, were shown to be related to cognitive dysfunction. This study explored the role of sleep in cognitive function of patients with abnormal glucose tolerance. A total of 162 patients (81 type 2 diabetes and 81 prediabetes) participated. Sleep duration and sleep efficiency (an indicator of sleep quality) were obtained using 7-day actigraphy recordings. Obstructive sleep apnea (OSA) was screened using an overnight in-home monitor. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Three sub-scores of MoCA, visuoexecutive function, attention and delayed recall, were also analyzed. Mean age was 54.8 (10.2) years. OSA was diagnosed in 123 participants (76.9%). Mean sleep duration was 6.0 (1.0) h and sleep efficiency was 82.7 (8.1) %. Sleep duration and OSA severity were not related to MoCA scores. Higher sleep efficiency was associated with higher MoCA scores (p = 0.003), and having diabetes (vs. prediabetes) was associated with lower MoCA scores (p = 0.001). After adjusting covariates, both having diabetes (vs. prediabetes) (B = - 1.137, p = 0.002) and sleep efficiency (B = 0.085, p < 0.001) were independently associated with MoCA scores. In addition, diabetes (B = - 0.608, p < 0.001) and sleep efficiency (B = 0.038, p < 0.001) were associated with visuoexecutive function. Sleep parameters were not related to delayed recall or attention scores. Lower sleep efficiency is independently associated with lower cognitive function in patients with abnormal glucose tolerance. Whether sleep optimization may improve cognitive function in these patients should be explored.

Sleep Does Not Enhance Motor Sequence Learning

ERIC Educational Resources Information Center

Rickard, Timothy C.; Cai, Denise J.; Rieth, Cory A.; Jones, Jason; Ard, M. Colin

2008-01-01

Improvements in motor sequence performance have been observed after a delay involving sleep. This finding has been taken as evidence for an active sleep consolidation process that enhances subsequent performance. In a review of this literature, however, the authors observed 4 aspects of data analyses and experimental design that could lead to…

Sleep-Dependent Learning and Motor-Skill Complexity

ERIC Educational Resources Information Center

Kuriyama, Kenichi; Stickgold, Robert; Walker, Matthew P.

2004-01-01

Learning of a procedural motor-skill task is known to progress through a series of unique memory stages. Performance initially improves during training, and continues to improve, without further rehearsal, across subsequent periods of sleep. Here, we investigate how this delayed sleep-dependent learning is affected when the task characteristics…

A brief tool to differentiate factors contributing to insomnia complaints.

PubMed

Townsend, Donald; Kazaglis, Louis; Savik, Kay; Smerud, Adam; Iber, Conrad

2017-03-01

A complaint of insomnia may have many causes. A brief tool examining contributing factors may be useful for nonsleep specialists. This study describes the development of the Insomnia Symptoms Assessment (ISA) for examining insomnia complaints. ISA questions were designed to identify symptoms that may represent 1 of 8 possible factors contributing to insomnia symptoms, including delayed sleep phase syndrome (DSPS), shift work sleep disorder (SWSD), obstructive sleep apnea (OSA), mental health, chronic pain, restless leg syndrome (RLS), poor sleep hygiene, and psychophysiological insomnia (PI). The ISA was completed by 346 new patients. Patients met with a sleep specialist who determined primary and secondary diagnoses. Mean age was 45 (18-85) years and 51% were male. Exploratory factor analysis (n = 217) and confirmatory factor analysis (n = 129) supported 5 factors with good internal consistency (Cronbach's alpha), including RLS (.72), OSA (.60), SWSD (.67), DSPS (.64), and PI (.80). Thirty percent had 1 sleep diagnosis with a mean of 2.2 diagnoses per patient. No diagnosis was entered for 1.2% of patients. The receiver operating characteristics were examined and the area under the curves calculated as an indication of convergent validity for the primary diagnosis (N = 346) were .97 for SWSD, .78 for OSA, .67 for DSPS, .54 for PI, and .80 for RLS. The ISA demonstrated good internal consistency and corresponds well to expert diagnoses. Next steps include setting sensitivity/specificity cutoffs to suggest initial treatment recommendations for use in other settings. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Memory effects of sleep, emotional valence, arousal and novelty in children.

PubMed

Vermeulen, Marije C M; van der Heijden, Kristiaan B; Benjamins, Jeroen S; Swaab, Hanna; van Someren, Eus J W

2017-06-01

Effectiveness of memory consolidation is determined by multiple factors, including sleep after learning, emotional valence, arousal and novelty. Few studies investigated how the effect of sleep compares with (and interacts with) these other factors, of which virtually none are in children. The present study did so by repeated assessment of declarative memory in 386 children (45% boys) aged 9-11 years through an online word-pair task. Children were randomly assigned to either a morning or evening learning session of 30 unrelated word-pairs with positive, neutral or negative valenced cues and neutral targets. After immediately assessing baseline recognition, delayed recognition was recorded either 12 or 24 h later, resulting in four different assessment schedules. One week later, the procedure was repeated with exactly the same word-pairs to evaluate whether effects differed for relearning versus original novel learning. Mixed-effect logistic regression models were used to evaluate how the probability of correct recognition was affected by sleep, valence, arousal, novelty and their interactions. Both immediate and delayed recognition were worse for pairs with negatively valenced or less arousing cue words. Relearning improved immediate and delayed word-pair recognition. In contrast to these effects, sleep did not affect recognition, nor did sleep moderate the effects of arousal, valence and novelty. The findings suggest a robust inclination of children to specifically forget the pairing of words to negatively valenced cue words. In agreement with a recent meta-analysis, children seem to depend less on sleep for the consolidation of information than has been reported for adults, irrespective of the emotional valence, arousal and novelty of word-pairs. © 2017 European Sleep Research Society.

Energy-saving scheme based on downstream packet scheduling in ethernet passive optical networks

NASA Astrophysics Data System (ADS)

Zhang, Lincong; Liu, Yejun; Guo, Lei; Gong, Xiaoxue

2013-03-01

With increasing network sizes, the energy consumption of Passive Optical Networks (PONs) has grown significantly. Therefore, it is important to design effective energy-saving schemes in PONs. Generally, energy-saving schemes have focused on sleeping the low-loaded Optical Network Units (ONUs), which tends to bring large packet delays. Further, the traditional ONU sleep modes are not capable of sleeping the transmitter and receiver independently, though they are not required to transmit or receive packets. Clearly, this approach contributes to wasted energy. Thus, in this paper, we propose an Energy-Saving scheme that is based on downstream Packet Scheduling (ESPS) in Ethernet PON (EPON). First, we design both an algorithm and a rule for downstream packet scheduling at the inter- and intra-ONU levels, respectively, to reduce the downstream packet delay. After that, we propose a hybrid sleep mode that contains not only ONU deep sleep mode but also independent sleep modes for the transmitter and the receiver. This ensures that the energy consumed by the ONUs is minimal. To realize the hybrid sleep mode, a modified GATE control message is designed that involves 10 time points for sleep processes. In ESPS, the 10 time points are calculated according to the allocated bandwidths in both the upstream and the downstream. The simulation results show that ESPS outperforms traditional Upstream Centric Scheduling (UCS) scheme in terms of energy consumption and the average delay for both real-time and non-real-time packets downstream. The simulation results also show that the average energy consumption of each ONU in larger-sized networks is less than that in smaller-sized networks; hence, our ESPS is better suited for larger-sized networks.

Prevalence of impaired memory in hospitalized adults and associations with in-hospital sleep loss.

PubMed

Calev, Hila; Spampinato, Lisa M; Press, Valerie G; Meltzer, David O; Arora, Vineet M

2015-07-01

Effective inpatient teaching requires intact patient memory, but studies suggest hospitalized adults may have memory deficits. Sleep loss among inpatients could contribute to memory impairment. To assess memory in older hospitalized adults, and to test the association between sleep quantity, sleep quality, and memory, in order to identify a possible contributor to memory deficits in these patients. Prospective cohort study. General medicine and hematology/oncology inpatient wards. Fifty-nine hospitalized adults at least 50 years of age with no diagnosed sleep disorder. Immediate memory and memory after a 24-hour delay were assessed using a word recall and word recognition task from the University of Southern California Repeatable Episodic Memory Test. A vignette-based memory task was piloted as an alternative test more closely resembling discharge instructions. Sleep duration and efficiency overnight in the hospital were measured using actigraphy. Mean immediate recall was 3.8 words out of 15 (standard deviation = 2.1). Forty-nine percent of subjects had poor memory, defined as immediate recall score of 3 or lower. Median immediate recognition was 11 words out of 15 (interquartile range [IQR] = 9-13). Median delayed recall score was 1 word, and median delayed recognition was 10 words (IQR = 8-12). In-hospital sleep duration and efficiency were not significantly associated with memory. The medical vignette score was correlated with immediate recall (r = 0.49, P < 0.01). About half of the inpatients studied had poor memory while in the hospital, signaling that hospitalization might not be an ideal teachable moment. In-hospital sleep was not associated with memory scores. © 2015 Society of Hospital Medicine.

Self-report surveys of student sleep and well-being: a review of use in the context of school start times.

PubMed

Ziporyn, Terra D; Malow, Beth A; Oakes, Kari; Wahlstrom, Kyla L

2017-12-01

A large body of literature supports the need to delay high school starting times to improve student health and well-being by allowing students an opportunity to get sufficient and appropriately timed sleep. However, a dearth of uniform and standardized tools has hampered efforts to collect data on adolescent sleep and related health behaviors that might be used to establish a need for, or to evaluate outcomes of, bell time delays. To assess validated tools available to schools and contrast them with tools that schools have actually used, we identified and reviewed published, validated self-report surveys of adolescent sleep and well-being, as well as unpublished surveys, used to assess student sleep and related health measures in US high schools considering later high school start times. Only three of the surveys reviewed had adequate psychometric properties and covered an appropriately wide range of health and academic questions to allow for discernment of outcomes in pre-post educational settings. The surveys exhibited marked variability in numerous areas, including focus, terminology, calculation of sleep duration, mode of administration, context of administration, and follow-up procedures. Our findings provide sleep researchers and school administrators with an overview of surveys that school districts have used, along with a deeper understanding of the challenges of choosing, designing, and administering self-report surveys in the context of changing school schedules. They also highlight the opportunities presented by these instruments to assess outcomes of delaying bell times, compare communities meaningfully, and establish the need for later school start times in individual school districts. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Prevalence of Impaired Memory in Hospitalized Adults and Associations with In-Hospital Sleep Loss

PubMed Central

Calev, Hila; Spampinato, Lisa M; Press, Valerie G; Meltzer, David O; Arora, Vineet M

2015-01-01

Background Effective inpatient teaching requires intact patient memory, but studies suggest hospitalized adults may have memory deficits. Sleep loss among inpatients could contribute to memory impairment. Objective To assess memory in older hospitalized adults, and to test the association between sleep quantity, sleep quality and memory, in order to identify a possible contributor to memory deficits in these patients. Design Prospective cohort study Setting General medicine and hematology/oncology inpatient wards Patients 59 hospitalized adults at least 50 years of age with no diagnosed sleep disorder. Measurements Immediate memory and memory after a 24-hour delay were assessed using a word recall and word recognition task from the University of Southern California Repeatable Episodic Memory Test (USC-REMT). A vignette-based memory task was piloted as an alternative test more closely resembling discharge instructions. Sleep duration and efficiency overnight in the hospital were measured using actigraphy. Results Mean immediate recall was 3.8 words out of 15 (SD=2.1). Forty-nine percent of subjects had poor memory, defined as immediate recall score of 3 or lower. Median immediate recognition was 11 words out of 15 (IQR=9, 13). Median delayed recall score was 1 word and median delayed recognition was 10 words (IQR= 8–12). In-hospital sleep duration and efficiency were not significantly associated with memory. The medical vignette score was correlated with immediate recall (r=0.49, p<0.01) Conclusions About half of inpatients studied had poor memory while in the hospital, signaling that hospitalization might not be an ideal teachable moment. In-hospital sleep was not associated with memory scores. PMID:25872763

Sleep habits in adolescents of Saudi Arabia; distinct patterns and extreme sleep schedules.

PubMed

Merdad, Roah A; Merdad, Leena A; Nassif, Rawan A; El-Derwi, Douaa; Wali, Siraj O

2014-11-01

There is a need for comprehensive studies on adolescents' sleep habits in the Middle Eastern region. The aim of this study was to investigate the sleep-wake patterns, prevalence of excessive daytime sleepiness (EDS), and disturbed sleep among adolescents in Saudi Arabia and to identify the associated factors. The study was a cross-sectional survey done on a random sample of 1035 high school students, ages 14-23 years, in Jeddah, Saudi Arabia. The response rate was 91%. Students filled a self-reported questionnaire that included sleep-wake questions, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Perceived Stress Scale, academic performance, and personal data. Students slept an average of 7.0 hours on school nights, with an average delay of 2.8 and 6.0 hours in weekend sleep and rise times, respectively. Around 1 in 10 students stayed up all night and slept after returning from school (exhibiting a reversed sleep cycle) on weeknights. This pattern was more prevalent among boys and students with lower grade point averages. The prevalence of sleep disturbance was 65%, and EDS was found in 37% of the students. Predictors of EDS were school type, stress, napping and caffeine use, while gender was a predictor of disturbed sleep. Adolescents in Saudi Arabia showed a high percentage of poor sleep quality. Compared with adolescents from other countries, they had a larger delay in weekend sleep and rise times. An alarming reversed sleep cycle on weekdays is present and highlights the need for further assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

Impact of 5-h phase advance on sleep architecture and physical performance in athletes.

PubMed

Petit, Elisabeth; Mougin, Fabienne; Bourdin, Hubert; Tio, Grégory; Haffen, Emmanuel

2014-11-01

Travel across time zones causes jet lag and is accompanied by deleterious effects on sleep and performance in athletes. These poor performances have been evaluated in field studies but not in laboratory conditions. The purpose of this study was to evaluate, in athletes, the impact of 5-h phase advance on the architecture of sleep and physical performances (Wingate test). In a sleep laboratory, 16 male athletes (age: 22.2 ± 1.7 years, height: 178.3 ± 5.6 cm, body mass: 73.6 ± 7.9 kg) spent 1 night in baseline condition and 2 nights, 1 week apart, in phase shift condition recorded by electroencephalography to calculate sleep architecture variables. For these last 2 nights, the clock was advanced by 5 h. Core body temperature rhythm was assessed continuously. The first night with phase advance decreased total sleep time, sleep efficiency, sleep onset latency, stage 2 of nonrapid eye movement (N2), and rapid eye movement (REM) sleep compared with baseline condition, whereas the second night decreased N2 and increased slow-wave sleep and REM, thus improving the quality of sleep. After phase advance, mean power improved, which resulted in higher lactatemia. Acrophase and bathyphase of temperature occurred earlier and amplitude decreased in phase advance but the period was not modified. These results suggest that a simulated phase shift contributed to the changes in sleep architecture, but did not significantly impair physical performances in relation with early phase adjustment of temperature to the new local time.

ACUTE ETHANOL DISRUPTS PHOTIC AND SEROTONERGIC CIRCADIAN CLOCK PHASE-RESETTING IN THE MOUSE

PubMed Central

Brager, Allison J.; Ruby, Christina L.; Prosser, Rebecca A.; Glass, J. David

2011-01-01

Background Alcohol abuse is associated with impaired circadian rhythms and sleep. Ethanol administration disrupts circadian clock phase-resetting, suggesting a mode for the disruptive effect of alcohol abuse on the circadian timing system. In this study, we extend previous work in C57BL/6J mice to: 1) characterize the SCN pharmacokinetics of acute systemic ethanol administration; 2) explore the effects of acute ethanol on photic and non-photic phase-resetting; and 2) determine if the SCN is a direct target for photic effects. Methods First, microdialysis was used to characterize the pharmacokinetics of acute i.p. injections of 3 doses of ethanol (0.5, 1.0 and 2.0 g/kg) in the mouse suprachiasmatic (SCN) circadian clock. Second, the effects of acute i.p. ethanol administration on photic phase-delays and serotonergic ([+]8-OH-DPAT-induced) phase-advances of the circadian activity rhythm were assessed. Third, the effects of reverse-microdialysis ethanol perfusion of the SCN on photic phase-resetting were characterized. Results Peak ethanol levels from the 3 doses of ethanol in the SCN occurred within 20–40 min post-injection with half-lives for clearance ranging from 0.6–1.8 hr. Systemic ethanol treatment dose-dependently attenuated photic and serotonergic phase-resetting. This treatment also did not affect basal SCN neuronal activity as assessed by Fos expression. Intra-SCN perfusion with ethanol markedly reduced photic phase-delays. Conclusions These results confirm that acute ethanol attenuates photic phase-delay shifts and serotonergic phase-advance shifts in the mouse. This dual effect could disrupt photic and non-photic entrainment mechanisms governing circadian clock timing. It is also significant that the SCN clock is a direct target for disruptive effects of ethanol on photic shifting. Such actions by ethanol could underlie the disruptive effects of alcohol abuse on behavioral, physiological, and endocrine rhythms associated with alcoholism. PMID:21463340

Later Start, Longer Sleep: Implications of Middle School Start Times

ERIC Educational Resources Information Center

Temkin, Deborah A.; Princiotta, Daniel; Ryberg, Renee; Lewin, Daniel S.

2018-01-01

Background: Although adolescents generally get less than the recommended 9 hours of sleep per night, research and effort to delay school start times have generally focused on high schools. This study assesses the relation between school start times and sleep in middle school students while accounting for potentially confounding demographic…

Meeting Teen Sleep Needs Creatively

ERIC Educational Resources Information Center

Wolfson, Amy R.; Carskadon, Mary A.

2005-01-01

Research on the sleep needs of adolescents and the influence of sleep on learning and behavior have captured the interest of school districts nationwide and in other countries as well. As a result, school officials are being urged to acknowledge the evidence and to adjust school schedules accordingly (e.g., to delay high school start times). The…

Delayed High School Starting Times. Information Capsule. Volume 0908

ERIC Educational Resources Information Center

Blazer, Christie

2009-01-01

Educators around the nation are considering pushing high school starting times back until later in the morning, based on evidence suggesting that amount of sleep and circadian rhythms play a part in adolescents' academic performance. While research confirms that adolescents do not get enough sleep and that insufficient sleep can negatively…

Later Start, Longer Sleep: Implications of Middle School Start Times.

PubMed

Temkin, Deborah A; Princiotta, Daniel; Ryberg, Renee; Lewin, Daniel S

2018-05-01

Although adolescents generally get less than the recommended 9 hours of sleep per night, research and effort to delay school start times have generally focused on high schools. This study assesses the relation between school start times and sleep in middle school students while accounting for potentially confounding demographic variables. Seventh and eighth grade students attending 8 late starting schools (∼8:00 am, n = 630) and 3 early starting schools (∼7:23 am, n = 343) from a diverse suburban school district completed online surveys about their sleep behaviors. Doubly robust inverse probability of treatment weighted regression estimates of the effects of later school start time on student bedtimes, sleep duration, and daytime sleepiness were generated. Attending a school starting 37 minutes later was associated with an average of 17 additional minutes of sleep per weeknight, despite an average bedtime 15 minutes later. Students attending late starting schools were less sleepy than their counterparts in early starting schools, and more likely to be wide awake. Later school start times were significantly associated with improved sleep outcomes for early adolescents, providing support for the movement to delay school start times for middle schools. © 2018, American School Health Association.

Sleep and circadian phase in a ship's crew.

PubMed

Arendt, Josephine; Middleton, Benita; Williams, Peter; Francis, Gavin; Luke, Claire

2006-06-01

Numerous factors influence the increased health risks of seamen. This study investigated sleep (by actigraphy) and the adaptation of the internal clock in watch-keeping crew compared to day workers, as possible contributory factors. Fourteen watch keepers, 4 h on, 8 h off (0800-1200/2000-2400 h, 1200-1600/2400-0400 h, 1600-2000/0400-0800 h) (fixed schedule, n = 6; rotating by delay weekly, n = 8), and 12 day workers participated during a voyage from the United Kingdom to Antarctica. They kept daily sleep diaries and wore wrist monitors for continuous recording of activity. Sleep parameters were derived from activity using the manufacturer's software and analyzed by repeated-measures ANOVA using SAS 8.2. Sequential urine samples were collected for 48 h weekly for 6-sulphatoxymelatonin measurement as an index of circadian rhythm timing. Individuals working watches of 1200-1600/2400-0400 h and 1600-2000/0400-0800 h had 2 sleeps daily, analyzed separately as main sleep (longest) and 2nd sleep. Main sleep duration was shorter in watch keepers than in day workers (p < 0.0001). Objective sleep quality was significantly compromised in rotaters compared to both day workers and fixed watch keepers, the most striking comparisons being sleep efficiency (percentage desired sleep time spent sleeping) main sleep (p < 0.0001) and sleep fragmentation (an index of restlessness) main sleep (p < 0.0001). The 2nd sleep was substantially less efficient than was the main sleep (p < 0.0001) for all watch keepers. There were few significant differences in sleep between the different watches in rotating watch keepers. Circadian timing remained constant in day workers. Timing of the 6-sulphatoxymelatonin rhythm was later for the watch of 1200-1600/2400-0400 h than for all others (1200-1600/2400-0400 h, 5.90 +/- 0.85 h; 1600-2000/0400-0800 h, 1.5 +/- 0.64 h; 0800-1200/ 2000-2400 h, 2.72 +/- 0.76 h; days, 2.09 +/- 0.68 h [decimal hours, mean +/- SEM]: ANOVA, p < 0.01). This study identifies weekly changes in watch time as a cause of poor sleep in watch keepers. The most likely mechanism is the inability of the internal clock to adapt rapidly to abrupt changes in schedule.

Setting Adolescents Up for Success: Promoting a Policy to Delay High School Start Times.

PubMed

Barnes, Margaux; Davis, Krista; Mancini, Mackenzie; Ruffin, Jasmine; Simpson, Tina; Casazza, Krista

2016-07-01

A unique biological shift in sleep cycles occurs during adolescence causing later sleep and wake times. This shift is not matched by a concurrent modification in school start times, resulting in sleep curtailment for a large majority of adolescents. Chronic inadequate sleep is associated with poor academic performance including executive function impairments, mood, and behavioral issues, as well as adverse health outcomes such as an increased risk of obesity, hypertension, and cardiovascular disease. In order to address sleep deficits and the potential negative outcomes associated with chronic sleep deprivation, the American Academy of Pediatrics (AAP) and US Centers for Disease Control and Prevention (CDC) support delaying school start times for middle and high school students. We summarize current evidence, explicate the need for policy change, and urge school districts to put adolescent students' health as top priority and implement school start times consistent with their developmental needs. Whereas substantial evidence illustrating adverse consequences of inadequate sleep on psychological and physical health, and recommendations exist to adapt daytime school schedules to match sleep needs have been released, actual implementation of these recommendations have been limited. This is a call to action for the implementation of AAP/CDC recommendations across the state and nation. © 2016, American School Health Association.

Sleep confers a benefit for retention of statistical language learning in 6.5month old infants.

PubMed

Simon, Katharine N S; Werchan, Denise; Goldstein, Michael R; Sweeney, Lucia; Bootzin, Richard R; Nadel, Lynn; Gómez, Rebecca L

2017-04-01

Infants show robust ability to track transitional probabilities within language and can use this information to extract words from continuous speech. The degree to which infants remember these words across a delay is unknown. Given well-established benefits of sleep on long-term memory retention in adults, we examine whether sleep similarly facilitates memory in 6.5month olds. Infants listened to an artificial language for 7minutes, followed by a period of sleep or wakefulness. After a time-matched delay for sleep and wakefulness dyads, we measured retention using the head-turn-preference procedure. Infants who slept retained memory for the extracted words that was prone to interference during the test. Infants who remained awake showed no retention. Within the nap group, retention correlated with three electrophysiological measures (1) absolute theta across the brain, (2) absolute alpha across the brain, and (3) greater fronto-central slow wave activity (SWA). Copyright © 2016 Elsevier Inc. All rights reserved.

Memory and Obstructive Sleep Apnea: A Meta-Analysis

PubMed Central

Wallace, Anna; Bucks, Romola S.

2013-01-01

Study Objectives: To examine episodic memory performance in individuals with obstructive sleep apnea (OSA). Design Meta-analysis was used to synthesize results from individual studies examining the impact of OSA on episodic memory performance. The performance of individuals with OSA was compared to healthy controls or normative data. Participants Forty-two studies were included, comprising 2,294 adults with untreated OSA and 1,364 healthy controls. Studies that recorded information about participants at baseline prior to treatment interventions were included in the analysis. Measurements Participants were assessed with tasks that included a measure of episodic memory: immediate recall, delayed recall, learning, and/or recognition memory. Results: The results of the meta-analyses provide evidence that individuals with OSA are significantly impaired when compared to healthy controls on verbal episodic memory (immediate recall, delayed recall, learning, and recognition) and visuo-spatial episodic memory (immediate and delayed recall), but not visual immediate recall or visuo-spatial learning. When patients were compared to norms, negative effects of OSA were found only in verbal immediate and delayed recall. Conclusions: This meta-analysis contributes to understanding of the nature of episodic memory deficits in individuals with OSA. Impairments to episodic memory are likely to affect the daily functioning of individuals with OSA. Citation Wallace A; Bucks RS. Memory and obstructive sleep apnea: a meta-analysis. SLEEP 2013;36(2):203-220. PMID:23372268

Cued Memory Reactivation During SWS Abolishes the Beneficial Effect of Sleep on Abstraction.

PubMed

Hennies, Nora; Lambon Ralph, Matthew A; Durrant, Simon J; Cousins, James N; Lewis, Penelope A

2017-08-01

Extracting regularities from stimuli in our environment and generalizing these to new situations are fundamental processes in human cognition. Sleep has been shown to enhance these processes, possibly by facilitating reactivation-triggered memory reorganization. Here, we assessed whether cued reactivation during slow wave sleep (SWS) promotes the beneficial effect of sleep on abstraction of statistical regularities. We used an auditory statistical learning task, in which the benefit of sleep has been firmly established. Participants were exposed to a probabilistically determined sequence of tones and subsequently tested for recognition of novel short sequences adhering to this same statistical pattern in both immediate and delayed recall sessions. In different groups, the exposure stream was replayed during SWS in the night between the recall sessions (SWS-replay group), in wake just before sleep (presleep replay group), or not at all (control group). Surprisingly, participants who received replay in sleep performed worse in the delayed recall session than the control and the presleep replay group. They also failed to show the association between SWS and task performance that has been observed in previous studies and was present in the controls. Importantly, sleep structure and sleep quality did not differ between groups, suggesting that replay during SWS did not impair sleep but rather disrupted or interfered with sleep-dependent mechanisms that underlie the extraction of the statistical pattern. These findings raise important questions about the scope of cued memory reactivation and the mechanisms that underlie sleep-related generalization. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

The relationship between sleep-wake cycle and cognitive functioning in young people with affective disorders.

PubMed

Carpenter, Joanne S; Robillard, Rébecca; Lee, Rico S C; Hermens, Daniel F; Naismith, Sharon L; White, Django; Whitwell, Bradley; Scott, Elizabeth M; Hickie, Ian B

2015-01-01

Although early-stage affective disorders are associated with both cognitive dysfunction and sleep-wake disruptions, relationships between these factors have not been specifically examined in young adults. Sleep and circadian rhythm disturbances in those with affective disorders are considerably heterogeneous, and may not relate to cognitive dysfunction in a simple linear fashion. This study aimed to characterise profiles of sleep and circadian disturbance in young people with affective disorders and examine associations between these profiles and cognitive performance. Actigraphy monitoring was completed in 152 young people (16-30 years; 66% female) with primary diagnoses of affective disorders, and 69 healthy controls (18-30 years; 57% female). Patients also underwent detailed neuropsychological assessment. Actigraphy data were processed to estimate both sleep and circadian parameters. Overall neuropsychological performance in patients was poor on tasks relating to mental flexibility and visual memory. Two hierarchical cluster analyses identified three distinct patient groups based on sleep variables and three based on circadian variables. Sleep clusters included a 'long sleep' cluster, a 'disrupted sleep' cluster, and a 'delayed and disrupted sleep' cluster. Circadian clusters included a 'strong circadian' cluster, a 'weak circadian' cluster, and a 'delayed circadian' cluster. Medication use differed between clusters. The 'long sleep' cluster displayed significantly worse visual memory performance compared to the 'disrupted sleep' cluster. No other cognitive functions differed between clusters. These results highlight the heterogeneity of sleep and circadian profiles in young people with affective disorders, and provide preliminary evidence in support of a relationship between sleep and visual memory, which may be mediated by use of antipsychotic medication. These findings have implications for the personalisation of treatments and improvement of functioning in young adults early in the course of affective illness.

Sleep inertia, sleep homeostatic, and circadian influences on higher-order cognitive functions

PubMed Central

Ronda, Joseph M.; Czeisler, Charles A.; Wright, Kenneth P.

2016-01-01

Summary Sleep inertia, sleep homeostatic, and circadian processes modulate cognition, including reaction time, memory, mood, and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-daylong study that included two 14-daylong 28h forced desynchrony protocols, to examine separate and interacting influences of sleep inertia, sleep homeostasis, and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved over the first ~2-4h of wakefulness (sleep inertia); worsened thereafter until scheduled bedtime (sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~9AM and ~9PM respectively, in individuals with a habitual waketime of 7AM). The relative influences of sleep inertia, sleep homeostasis, and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation, and/or upon awakening from sleep. PMID:25773686

Energy-saving EPON Bandwidth Allocation Algorithm Supporting ONU's Sleep Mode

NASA Astrophysics Data System (ADS)

Zhang, Yinfa; Ren, Shuai; Liao, Xiaomin; Fang, Yuanyuan

2014-09-01

A new bandwidth allocation algorithm was presented by combining merits of the IPACT algorithm and the cyclic DBA algorithm based on the DBA algorithm for ONU's sleep mode. Simulation results indicate that compared with the normal mode ONU, the ONU's sleep mode can save about 74% of energy. The new algorithm has a smaller average packet delay and queue length in the upstream direction. While in the downstream direction, the average packet delay of the new algorithm is less than polling cycle Tcycle and the average queue length is less than the product of Tcycle and the maximum link rate. The new algorithm achieves a better compromise between energy-saving and ensuring quality of service.

Light-Induced Changes of the Circadian Clock of Humans: Increasing Duration is More Effective than Increasing Light Intensity

PubMed Central

Dewan, Karuna; Benloucif, Susan; Reid, Kathryn; Wolfe, Lisa F.; Zee, Phyllis C.

2011-01-01

Study Objectives: To evaluate the effect of increasing the intensity and/or duration of exposure on light-induced changes in the timing of the circadian clock of humans. Design: Multifactorial randomized controlled trial, between and within subject design Setting: General Clinical Research Center (GCRC) of an academic medical center Participants: 56 healthy young subjects (20-40 years of age) Interventions: Research subjects were admitted for 2 independent stays of 4 nights/3 days for treatment with bright or dim-light (randomized order) at a time known to induce phase delays in circadian timing. The intensity and duration of the bright light were determined by random assignment to one of 9 treatment conditions (duration of 1, 2, or 3 hours at 2000, 4000, or 8000 lux). Measurements and Results: Treatment-induced changes in the dim light melatonin onset (DLMO) and dim light melatonin offset (DLMOff) were measured from blood samples collected every 20-30 min throughout baseline and post-treatment nights. Comparison by multi-factor analysis of variance (ANOVA) of light-induced changes in the time of the circadian melatonin rhythm for the 9 conditions revealed that changing the duration of the light exposure from 1 to 3 h increased the magnitude of light-induced delays. In contrast, increasing from moderate (2,000 lux) to high (8,000 lux) intensity light did not alter the magnitude of phase delays of the circadian melatonin rhythm. Conclusions: Results from the present study suggest that for phototherapy of circadian rhythm sleep disorders in humans, a longer period of moderate intensity light may be more effective than a shorter exposure period of high intensity light. Citation: Dewan K; Benloucif S; Reid K; Wolfe LF; Zee PC. Light-induced changes of the circadian clock of humans: increasing duration is more effective than increasing light intensity. SLEEP 2011;34(5):593-599. PMID:21532952

Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.

PubMed

Burke, Tina M; Scheer, Frank A J L; Ronda, Joseph M; Czeisler, Charles A; Wright, Kenneth P

2015-08-01

Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep. © 2015 European Sleep Research Society.

School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: A Review of the Literature

ERIC Educational Resources Information Center

Wheaton, Anne G.; Chapman, Daniel P.; Croft, Janet B.

2016-01-01

Background: Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy…

An Efficient Power Saving Mechanism for Delay-Guaranteed Services in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Park, Yunju; Hwang, Gang Uk

As the IEEE 802.16e Wireless Metropolitan Access Network (WMAN) supports the mobility of a mobile station (MS), increasing MS power efficiency has become an important issue. In this paper, we analyze the sleep-mode operation for an efficient power saving mechanism for delay-guaranteed services in the IEEE 802.16e WMAN and observe the effects of the operating parameters related to this operation. For the analysis we use the M/GI/1/K queueing system with multiple vacations, exhaustive services and setup times. In the analysis, we consider the power consumption during the wake-mode period as well as the sleep-mode period. As a performance measure for the power consumption, we propose the power consumption per unit time per effective arrival which considers the power consumption and the packet blocking probability simultaneously. In addition, since we consider delay-guaranteed services, the average packet response delay is also considered as a performance measure. Based on the performance measures, we obtain the optimal sleep-mode operation which minimizes the power consumption per unit time per effective arrival with a given delay requirement. Numerical studies are also provided to investigate the system performance and to show how to achieve our objective.

Variation of electroencephalographic activity during non-rapid eye movement and rapid eye movement sleep with phase of circadian melatonin rhythm in humans.

PubMed Central

Dijk, D J; Shanahan, T L; Duffy, J F; Ronda, J M; Czeisler, C A

1997-01-01

1. The circadian pacemaker regulates the timing, structure and consolidation of human sleep. The extent to which this pacemaker affects electroencephalographic (EEG) activity during sleep remains unclear. 2. To investigate this, a total of 1.22 million power spectra were computed from EEGs recorded in seven men (total, 146 sleep episodes; 9 h 20 min each) who participated in a one-month-long protocol in which the sleep-wake cycle was desynchronized from the rhythm of plasma melatonin, which is driven by the circadian pacemaker. 3. In rapid eye movement (REM) sleep a small circadian variation in EEG activity was observed. The nadir of the circadian rhythm of alpha activity (8.25-10.5 Hz) coincided with the end of the interval during which plasma melatonin values were high, i.e. close to the crest of the REM sleep rhythm. 4. In non-REM sleep, variation in EEG activity between 0.25 and 11.5 Hz was primarily dependent on prior sleep time and only slightly affected by circadian phase, such that the lowest values coincided with the phase of melatonin secretion. 5. In the frequency range of sleep spindles, high-amplitude circadian rhythms with opposite phase positions relative to the melatonin rhythm were observed. Low-frequency sleep spindle activity (12.25-13.0 Hz) reached its crest and high-frequency sleep spindle activity (14.25-15.5 Hz) reached its nadir when sleep coincided with the phase of melatonin secretion. 6. These data indicate that the circadian pacemaker induces changes in EEG activity during REM and non-REM sleep. The changes in non-REM sleep EEG spectra are dissimilar from the spectral changes induced by sleep deprivation and exhibit a close temporal association with the melatonin rhythm and the endogenous circadian phase of sleep consolidation. PMID:9457658

School start time and sleep in Canadian adolescents.

PubMed

Gariépy, Geneviève; Janssen, Ian; Sentenac, Mariane; Elgar, Frank J

2017-04-01

Insufficient sleep is a serious problem in adolescents and school start time is thought to be a key contributor. This study provided the first comprehensive assessment of school start times across Canada and examined whether school start times were associated with sleep duration and tiredness among adolescents. We collected information on school start times from 362 schools that participated in the 2013/2014 Health Behaviour in School-aged Children study. We calculated sleep duration from weekday bedtime and wake time reported by 29 635 students (aged 10-18 years). We classified weekday sleep as sufficient if it met national recommendations, and used data on self-reported tiredness at school in the morning. Random-effects regression models estimated the association of school start time with sleep duration, sleep sufficiency and tiredness. On average, schools started at 08:43 hours. Students slept an average of 8:36 h on weekdays and 69% met sleep duration recommendations, but 60% reported feeling tired in the morning. Every 10-min delay in school start time corresponded with 3.2 [95% confidence interval (CI): 2.0, 4.5] additional minutes of sleep, a 1.6% (95% CI: 0.5, 2.8) greater probability of sufficient sleep and a 2.1% (95% CI: 1.0, 3.2) smaller probability of feeling tired at school in the morning. Students from schools that started later slept longer, were more likely to meet sleep recommendations and were less likely to report feeling tired in the morning. The study adds weight to the mounting evidence that delaying school start time benefits adolescent sleep. © 2016 European Sleep Research Society.

A structural equation model of the relationship between insomnia, negative affect, and paranoid thinking

PubMed Central

Rowse, Georgina; Webb, Thomas L.

2017-01-01

Background A growing body of evidence points to relationships between insomnia, negative affect, and paranoid thinking. However, studies are needed to examine (i) whether negative affect mediates the relation between insomnia and paranoid thinking, (ii) whether different types of insomnia exert different effects on paranoia, and (iii) to compare the impact of objective and self-reported sleeping difficulties. Method Structural equation modelling was therefore used to test competing models of the relationships between self-reported insomnia, negative affect, and paranoia. n = 348 participants completed measures of insomnia, negative affect and paranoia. A subset of these participants (n = 91) went on to monitor their sleep objectively (using a portable sleep monitor made by Zeo) for seven consecutive nights. Associations between objectively recorded sleep, negative affect, and paranoia were explored using linear regression. Results The findings supported a fully mediated model where self-reported delayed sleep onset, but not self-reported problems with sleep maintenance or objective measures of sleep, was directly associated with negative affect that, in turn, was associated with paranoia. There was no evidence of a direct association between delayed sleep onset or sleep maintenance problems and paranoia. Conclusions Taken together, the findings point to an association between perceived (but not objective) difficulties initially falling asleep (but not maintaining sleep) and paranoid thinking; a relationship that is fully mediated by negative affect. Future research should seek to disentangle the causal relationships between sleep, negative affect, and paranoia (e.g., by examining the effect of an intervention using prospective designs that incorporate experience sampling). Indeed, interventions might profitably target (i) perceived sleep quality, (ii) sleep onset, and / or (iii) emotion regulation as a route to reducing negative affect and, thus, paranoid thinking. PMID:29049381

Digital sleep logs reveal potential impacts of modern temporal structure on class performance in different chronotypes.

PubMed

Smarr, Benjamin Lee

2015-02-01

Stability of sleep and circadian rhythms are important for healthy learning and memory. While experimental manipulations of lifestyle and learning outcomes present major obstacles, the ongoing increase in data sources allows retrospective data mining of people's sleep timing variation. Here I use digital sleep-log data generated by 1109 students in a biology lab course at the University of Washington to test the hypothesis that higher variance in time asleep and later sleep-onset times negatively correlate with class performance, used here as a real-world proxy for learning and memory. I find that sleep duration variance and mean sleep-onset times both significantly correlate with class performance. These correlations are powerful on weeknights but undetectable on Friday and Saturday nights ("free nights"). Finally, although these data come with no demographic information beyond sex, the constructed demographic groups of "larks" and "owls" within the sexes reveal a significant decrease in performance of owls relative to larks in male students, whereas the correlation of performance with sleep-onset time for all male students was only a near-significant trend. This provides a proof of concept that deeper demographic mining of digital logs in the future may identify subgroups for which certain sleep phenotypes have greater predictive value for performance outcomes. The data analyzed are consistent with known patterns, including sleep-timing delays from weeknights to free nights and sleep-timing delays in men relative to women. These findings support the hypothesis that modern schedule impositions on sleep and circadian timing have consequences for real-world learning and memory. This study also highlights the low-cost, large-scale benefits of personal, daily, digital records as an augmentation of sleep and circadian studies. © 2015 The Author(s).

Short-term sleep disturbance-induced stress does not affect basal pain perception, but does delay postsurgical pain recovery

PubMed Central

Wang, Po-Kai; Cao, Jing; Wang, Hongzhen; Liang, Lingli; Zhang, Jun; Lutz, Brianna Marie; Shieh, Kun-Ruey; Bekker, Alex; Tao, Yuan-Xiang

2015-01-01

Chronic sleep disturbance-induced stress is known to increase basal pain sensitivity. However, most surgical patients frequently report short-term sleep disturbance/deprivation during pre- and post-operation periods and have normal pain perception pre-surgery. Whether this short-term sleep disturbance affects postsurgical pain is elusive. We here reported that pre- or post-exposure to rapid eye movement sleep disturbance (REMSD) 6 h daily for 3 consecutive days did not alter basal responses to mechanical, heat, and cold stimuli, but did delay recovery in incision-induced reductions in paw withdrawal threshold to mechanical stimulation and paw withdrawal latencies to heat and cold stimuli on the ipsilateral side of male or female rats. This short-term REMSD led to stress evidenced by an increase in swim immobility time, a decrease in sucrose consumption, and an elevation in the level of corticosterone in serum. Blocking this stress via intrathecal RU38486 or bilateral adrenalectomy abolished REMSD-caused delay in recovery of incision-induced reductions in behavioral responses to mechanical, heat, and cold stimuli. Moreover, this short-term REMSD produced significant reductions in the levels of mu opioid receptor and kappa opioid receptor, but not Kv1.2, in the ipsilateral L4/5 spinal cord and dorsal root ganglia on day 9 post-incision (but not post-sham surgery). PMID:26342649

Paul Hagenmüller's contribution to solid state chemistry: A scientometric analysis

NASA Astrophysics Data System (ADS)

El Aichouchi, Adil; Gorry, Philippe

2018-06-01

Paul Hagenmüller (1921-2017) is an important figure of French solid-state chemistry, who enjoyed scientific and institutional recognition. He published 796 papers and has been cited more than 16,000 times. This paper explores Hagenmüller's work using scientometric analysis to reveal the impact of his work, his main research topics and his collaborations. Although Hagenmüller was a recognized scientist, a subset of his work, now highly cited, attracted little attention at the time of publication. To understand this phenomenon, we detect and study papers with delayed recognition, also called 'Sleeping Beauties' (SBs). In scientometrics, SBs are publications that go unnoticed, or 'sleep' for a long time before suddenly attracting a lot of attention in terms of citations. We identify 7 SBs published between 1965 and 1985, and awakened between 1993 and 2010. The first SB reports the discovery of the clathrate structure of silicon. The second reports the isolation of four new phases with the formula NaxCoO2 (x < =1). The five other SBs investigate the electrochemical intercalation and deintercalation of sodium, and the structure and properties of layered oxides. Through interviews with his coworkers, we attempt to identify the reasons for the delayed recognition and the context of the renewed interest in those papers.

Current role of melatonin in pediatric neurology: clinical recommendations.

PubMed

Bruni, Oliviero; Alonso-Alconada, Daniel; Besag, Frank; Biran, Valerie; Braam, Wiebe; Cortese, Samuele; Moavero, Romina; Parisi, Pasquale; Smits, Marcel; Van der Heijden, Kristiaan; Curatolo, Paolo

2015-03-01

Melatonin, an indoleamine secreted by the pineal gland, plays a key role in regulating circadian rhythm. It has chronobiotic, antioxidant, anti-inflammatory and free radical scavenging properties. A conference in Rome in 2014 aimed to establish consensus on the roles of melatonin in children and on treatment guidelines. The best evidence for efficacy is in sleep onset insomnia and delayed sleep phase syndrome. It is most effective when administered 3-5 h before physiological dim light melatonin onset. There is no evidence that extended-release melatonin confers advantage over immediate release. Many children with developmental disorders, such as autism spectrum disorder, attention-deficit/hyperactivity disorder and intellectual disability have sleep disturbance and can benefit from melatonin treatment. Melatonin decreases sleep onset latency and increases total sleep time but does not decrease night awakenings. Decreased CYP 1A2 activity, genetically determined or from concomitant medication, can slow metabolism, with loss of variation in melatonin level and loss of effect. Decreasing the dose can remedy this. Animal work and limited human data suggest that melatonin does not exacerbate seizures and might decrease them. Melatonin has been used successfully in treating headache. Animal work has confirmed a neuroprotective effect of melatonin, suggesting a role in minimising neuronal damage from birth asphyxia; results from human studies are awaited. Melatonin can also be of value in the performance of sleep EEGs and as sedation for brainstem auditory evoked potential assessments. No serious adverse effects of melatonin in humans have been identified. Copyright © 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light

PubMed Central

Tam, Shu K. E.; Hughes, Steven; Jagannath, Aarti; Hankins, Mark W.; Bannerman, David M.; Lightman, Stafford L.; Vyazovskiy, Vladyslav V.; Nolan, Patrick M.; Foster, Russell G.; Peirson, Stuart N.

2016-01-01

Light plays a critical role in the regulation of numerous aspects of physiology and behaviour, including the entrainment of circadian rhythms and the regulation of sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) in addition to rods and cones. Nocturnal light exposure in rodents has been shown to result in rapid sleep induction, in which melanopsin plays a key role. However, studies have also shown that light exposure can result in elevated corticosterone, a response that is not compatible with sleep. To investigate these contradictory findings and to dissect the relative contribution of pRGCs and rods/cones, we assessed the effects of light of different wavelengths on behaviourally defined sleep. Here, we show that blue light (470 nm) causes behavioural arousal, elevating corticosterone and delaying sleep onset. By contrast, green light (530 nm) produces rapid sleep induction. Compared to wildtype mice, these responses are altered in melanopsin-deficient mice (Opn4-/-), resulting in enhanced sleep in response to blue light but delayed sleep induction in response to green or white light. We go on to show that blue light evokes higher Fos induction in the SCN compared to the sleep-promoting ventrolateral preoptic area (VLPO), whereas green light produced greater responses in the VLPO. Collectively, our data demonstrates that nocturnal light exposure can have either an arousal- or sleep-promoting effect, and that these responses are melanopsin-mediated via different neural pathways with different spectral sensitivities. These findings raise important questions relating to how artificial light may alter behaviour in both the work and domestic setting. PMID:27276063

Ambulatory sleep-wake patterns and variability in young people with emerging mental disorders.

PubMed

Robillard, Rébecca; Hermens, Daniel F; Naismith, Sharon L; White, Django; Rogers, Naomi L; Ip, Tony K C; Mullin, Sharon J; Alvares, Gail A; Guastella, Adam J; Smith, Kristie Leigh; Rong, Ye; Whitwell, Bradley; Southan, James; Glozier, Nick; Scott, Elizabeth M; Hickie, Ian B

2015-01-01

The nature of sleep-wake abnormalities in individuals with mental disorders remains unclear. The present study aimed to examine the differences in objective ambulatory measures of the sleep-wake and activity cycles across young people with anxiety, mood or psychotic disorders. Participants underwent several days of actigraphy monitoring. We divided participants into 5 groups (control, anxiety disorder, unipolar depression, bipolar disorder, psychotic disorder) according to primary diagnosis. We enrolled 342 participants aged 12-35 years in our study: 41 healthy controls, 56 with anxiety disorder, 135 with unipolar depression, 80 with bipolar disorder and 30 with psychotic disorders. Compared with the control group, sleep onset tended to occur later in the anxiety, depression and bipolar groups; sleep offset occurred later in all primary diagnosis groups; the sleep period was longer in the anxiety, bipolar and psychosis groups; total sleep time was longer in the psychosis group; and sleep efficiency was lower in the depression group, with a similar tendency for the anxiety and bipolar groups. Sleep parameters were significantly more variable in patient subgroups than in controls. Cosinor analysis revealed delayed circadian activity profiles in the anxiety and bipolar groups and abnormal circadian curve in the psychosis group. Although statistical analyses controlled for age, the sample included individuals from preadolescence to adulthood. Most participants from the primary diagnosis subgroups were taking psychotropic medications, and a large proportion had other comorbid mental disorders. Our findings suggest that delayed and disorganized sleep offset times are common in young patients with various mental disorders. However, other sleep-wake cycle disturbances appear to be more prominent in broad diagnostic categories.

Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light.

PubMed

Pilorz, Violetta; Tam, Shu K E; Hughes, Steven; Pothecary, Carina A; Jagannath, Aarti; Hankins, Mark W; Bannerman, David M; Lightman, Stafford L; Vyazovskiy, Vladyslav V; Nolan, Patrick M; Foster, Russell G; Peirson, Stuart N

2016-06-01

Light plays a critical role in the regulation of numerous aspects of physiology and behaviour, including the entrainment of circadian rhythms and the regulation of sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) in addition to rods and cones. Nocturnal light exposure in rodents has been shown to result in rapid sleep induction, in which melanopsin plays a key role. However, studies have also shown that light exposure can result in elevated corticosterone, a response that is not compatible with sleep. To investigate these contradictory findings and to dissect the relative contribution of pRGCs and rods/cones, we assessed the effects of light of different wavelengths on behaviourally defined sleep. Here, we show that blue light (470 nm) causes behavioural arousal, elevating corticosterone and delaying sleep onset. By contrast, green light (530 nm) produces rapid sleep induction. Compared to wildtype mice, these responses are altered in melanopsin-deficient mice (Opn4-/-), resulting in enhanced sleep in response to blue light but delayed sleep induction in response to green or white light. We go on to show that blue light evokes higher Fos induction in the SCN compared to the sleep-promoting ventrolateral preoptic area (VLPO), whereas green light produced greater responses in the VLPO. Collectively, our data demonstrates that nocturnal light exposure can have either an arousal- or sleep-promoting effect, and that these responses are melanopsin-mediated via different neural pathways with different spectral sensitivities. These findings raise important questions relating to how artificial light may alter behaviour in both the work and domestic setting.

The effects of partial sleep restriction and altered sleep timing on appetite and food reward.

PubMed

McNeil, Jessica; Forest, Geneviève; Hintze, Luzia Jaeger; Brunet, Jean-François; Finlayson, Graham; Blundell, John E; Doucet, Éric

2017-02-01

We examined the effects of partial sleep restriction (PSR) with an advanced wake-time or delayed bedtime on measures of appetite, food reward and subsequent energy intake (EI). Twelve men and 6 women (age: 23 ± 4 years, body fat: 18.8 ± 10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-time), 50% PSR with an advanced wake-time and 50% PSR with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), ad libitum EI (validated food menu), appetite sensations (visual analogue scales), satiety quotient (SQ; mm/100 kcal) and food reward (Leeds Food Preference Questionnaire and the relative-reinforcing value (RRV) of preferred food task). Increased fasting and post-standard breakfast appetite ratings were noted following PSR with an advanced wake-time compared to the control and PSR with a delayed bedtime sessions (Fasting hunger ratings: 77 ± 16 vs. 65 ± 18 and 64 ± 16; P = 0.01; Post-meal hunger AUC: 5982 ± 1781 vs. 4508 ± 2136 and 5198 ± 2201; P = 0.03). Increased explicit wanting and liking for high- relative to low-fat foods were also noted during the advanced wake-time vs. control session (Explicit wanting: -3.5 ± 12.5 vs. -9.3 ± 8.9, P = 0.01; Explicit liking: -1.6 ± 8.5 vs. -7.8 ± 9.6, P = 0.002). No differences in the RRV of preferred food, SQ and ad libitum lunch intake were noted between sessions. These findings suggest that appetite sensations and food reward are increased following PSR with an advanced wake-time, rather than delayed bedtime, vs. However, this did not translate into increased EI during a test meal. Given the increasing prevalence of shift workers and incidences of sleep disorders, additional studies are needed to evaluate the prolonged effects of voluntary sleep restriction with altered sleep timing on appetite and EI measurements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Getting through to circadian oscillators: why use constant routines?

NASA Technical Reports Server (NTRS)

Duffy, Jeanne F.; Dijk, Derk-Jan

2002-01-01

Overt 24-h rhythmicity is composed of both exogenous and endogenous components, reflecting the product of multiple (periodic) feedback loops with a core pacemaker at their center. Researchers attempting to reveal the endogenous circadian (near 24-h) component of rhythms commonly conduct their experiments under constant environmental conditions. However, even under constant environmental conditions, rhythmic changes in behavior, such as food intake or the sleep-wake cycle, can contribute to observed rhythmicity in many physiological and endocrine variables. Assessment of characteristics of the core circadian pacemaker and its direct contribution to rhythmicity in different variables, including rhythmicity in gene expression, may be more reliable when such periodic behaviors are eliminated or kept constant across all circadian phases. This is relevant for the assessment of the status of the circadian pacemaker in situations in which the sleep-wake cycle or food intake regimes are altered because of external conditions, such as in shift work or jet lag. It is also relevant for situations in which differences in overt rhythmicity could be due to changes in either sleep oscillatory processes or circadian rhythmicity, such as advanced or delayed sleep phase syndromes, in aging, or in particular clinical conditions. Researchers studying human circadian rhythms have developed constant routine protocols to assess the status of the circadian pacemaker in constant behavioral and environmental conditions, whereas this technique is often thought to be unnecessary in the study of animal rhythms. In this short review, the authors summarize constant routine methodology and what has been learned from constant routines and argue that animal and human circadian rhythm researchers should (continue to) use constant routines as a step on the road to getting through to central and peripheral circadian oscillators in the intact organism.

Sleep disturbances in young and middle-aged adults - Empirical patterns and related factors from an epidemiological survey.

PubMed

Rössler, Wulf; AjdacicGross, Vladeta; Glozier, Nick; Rodgers, Stephanie; Haker, Helene; Müller, Mario

2017-10-01

Previous research suggests that sleep disorders are highly associated with other mental health problems. However, sleep problems even below the diagnostic threshold of sleep disorders are very common in the general population, which highly affects wellbeing and functioning. In order to broaden the focus beyond those severe cases we explored empirical patterns across the whole spectrum of sleep problems as well as associated clinical and other factors. A representative community sample of N=1274 residents from the canton of Zurich was interviewed for sleep problems and diagnostic criteria for mental disorders as well as was given a number of mental health-related psychometrical checklists. Based on a broader spectrum of sleep problems we conducted a latent class analysis (LCA) to derive distinct classes of such disturbances. Classes were compared regarding their associations to mental health-relevant and other risk factors. The LCA revealed four classes - no sleep disturbances (72.6%), difficulties initiating and maintaining sleep (15.8%), delayed sleep (5.3%), and severe sleep problems (6.4%). Severe sleep problems were related to female gender and generalized anxiety disorder, while depression was linked to all sleep problem classes. Persons with difficulties initiating and maintaining sleep and severe sleep problems reported higher levels of psychopathology, burnout and neuroticism, while all sleep problem types were tied to stress-related variables, but not alcohol use disorder. Sleep problems are highly prevalent among the young and middle-aged adults in our representative sample of young and middle-aged adults and as such represent a serious public mental health problem. Our findings indicate sleep problems to have a multi-dimensional structure with some differential associations. While all subtypes were associated with poorer mental health and particularly more depression, severe sleep problems appeared to be the sleep subtype seen in agoraphobia and GAD, while delayed sleep had no specific associations. The variety of associations assessed leads one to assume that likewise a variety of sleep interventions is required. Copyright © 2017 Elsevier Inc. All rights reserved.

REM Sleep Phase Preference in the Crepuscular Octodon degus Assessed by Selective REM Sleep Deprivation

PubMed Central

Ocampo-Garcés, Adrián; Hernández, Felipe; Palacios, Adrian G.

2013-01-01

Study Objectives: To determine rapid eye movement (REM) sleep phase preference in a crepuscular mammal (Octodon degus) by challenging the specific REM sleep homeostatic response during the diurnal and nocturnal anticrepuscular rest phases. Design: We have investigated REM sleep rebound, recovery, and documented REM sleep propensity measures during and after diurnal and nocturnal selective REM sleep deprivations. Subjects: Nine male wild-captured O. degus prepared for polysomnographic recordings Interventions: Animals were recorded during four consecutive baseline and two separate diurnal or nocturnal deprivation days, under a 12:12 light-dark schedule. Three-h selective REM sleep deprivations were performed, starting at midday (zeitgeber time 6) or midnight (zeitgeber time 18). Measurements and Results: Diurnal and nocturnal REM sleep deprivations provoked equivalent amounts of REM sleep debt, but a consistent REM sleep rebound was found only after nocturnal deprivation. The nocturnal rebound was characterized by a complete recovery of REM sleep associated with an augment in REM/total sleep time ratio and enhancement in REM sleep episode consolidation. Conclusions: Our results support the notion that the circadian system actively promotes REM sleep. We propose that the sleep-wake cycle of O. degus is modulated by a chorus of circadian oscillators with a bimodal crepuscular modulation of arousal and a unimodal promotion of nocturnal REM sleep. Citation: Ocampo-Garcés A; Hernández F; Palacios AG. REM sleep phase preference in the crepuscular Octodon degus assessed by selective REM sleep deprivation. SLEEP 2013;36(8):1247-1256. PMID:23904685

Effects of lunar phase on sleep in men and women in Surrey.

PubMed

Della Monica, Ciro; Atzori, Giuseppe; Dijk, Derk-Jan

2015-12-01

Recently, evidence has emerged that the phases of the moon may modulate subjective sleep quality and polysomnographically assessed sleep structure in humans. We aimed to explore further the putative effects of circa-lunar periodicity (~29.5 days) on subjective and objective parameters of human sleep in a retrospective analysis. The baseline sleep recordings of 205 (91 males and 114 females; mean age = 47.47 years, standard deviation =19.01; range: 20-84 years) healthy and carefully screened participants who participated in two clinical trials in the Surrey Clinical Research Centre were included in the analyses. Sleep was recorded in windowless sleep laboratories. For each study night, we calculated the distance, in days, to the date of the closest full moon phase and based on this distance, classified sleep records in three lunar classes. Univariate analysis of variance with factors lunar class, age and sex was applied to each of 21 sleep parameters. No significant main effect for the factor lunar class was observed for any of the objective sleep parameters and subjective sleep quality but some significant interactions were observed. The interaction between lunar class and sex was significant for total sleep time, Stage 4 sleep and rapid eye movement (REM) sleep. Separate analyses for men and women indicated that in women total sleep time, Stage 4 sleep and REM sleep were reduced when sleep occurred close to full moon, whereas in men REM duration increased around full moon. These data provide limited evidence for an effect of lunar phase on human sleep. © 2015 European Sleep Research Society.

The Relations Between Sleep, Personality, Behavioral Problems, and School Performance in Adolescents.

PubMed

Schmidt, Ralph E; Van der Linden, Martial

2015-06-01

According to recent meta-analyses, adolescents across different countries and cultures do not get the recommended amount of sleep. Extracurricular activities, part-time jobs, and use of electronic devices in the evening delay bedtime in adolescents. Early school start times also shorten the time for sleep. Insufficient sleep in adolescents has been associated with weakened emotional-behavioral regulation and poor academic achievement. Multicomponent intervention programs have been developed on the basis of cognitive-behavioral therapy for insomnia to improve sleep in youth. Copyright © 2015 Elsevier Inc. All rights reserved.

Does 'anchor sleep' entrain circadian rhythms? Evidence from constant routine studies.

PubMed Central

Minors, D S; Waterhouse, J M

1983-01-01

Experiments have been performed in an isolation unit to investigate the effects of abnormal sleep-waking schedules upon circadian rhythms of renal excretion and deep-body temperature. In confirmation of previous work, nychthemeral rhythms appeared to be 'anchored' to a 24 h period if 4 h sleep was taken regularly each day, even though another 4 h was taken irregularly. The endogenous components were investigated by assessing circadian rhythmicity under constant routine conditions, that is, when rhythmic influences in the environment and sleep-waking pattern had been minimized. Analysis of the constant routine data indicated the presence of a rhythmic component which had been stabilized to a period of 24 h by the 'anchor sleep'. In addition, a delayed component was also present. The starting time of the constant routines produced a direct effect upon the rhythms, which was presumed to result from removing the 'masking' effect that sleep normally exerts upon rhythms. There was some evidence that the relative importance of the masking effect and the delayed component depended upon the variable under consideration. The implications of these findings, in terms of the effects of anchor sleep, the presence of more than one internal clock and the usefulness of constant routines, are discussed. PMID:6663508

The effects of self-selected light-dark cycles and social constraints on human sleep and circadian timing: a modeling approach.

PubMed

Skeldon, Anne C; Phillips, Andrew J K; Dijk, Derk-Jan

2017-03-27

Why do we go to sleep late and struggle to wake up on time? Historically, light-dark cycles were dictated by the solar day, but now humans can extend light exposure by switching on artificial lights. We use a mathematical model incorporating effects of light, circadian rhythmicity and sleep homeostasis to provide a quantitative theoretical framework to understand effects of modern patterns of light consumption on the human circadian system. The model shows that without artificial light humans wakeup at dawn. Artificial light delays circadian rhythmicity and preferred sleep timing and compromises synchronisation to the solar day when wake-times are not enforced. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity ('social jet-lag'). The model implies that developmental changes in sleep homeostasis and circadian amplitude make adolescents particularly sensitive to effects of light consumption. The model predicts that ameliorating social jet-lag is more effectively achieved by reducing evening light consumption than by delaying social constraints, particularly in individuals with slow circadian clocks or when imposed wake-times occur after sunrise. These theory-informed predictions may aid design of interventions to prevent and treat circadian rhythm-sleep disorders and social jet-lag.

Partial sleep deprivation by environmental noise increases food intake and body weight in obesity resistant rats

PubMed Central

Mavanji, Vijayakumar; Teske, Jennifer A.; Billington, Charles J.; Kotz, Catherine M.

2012-01-01

Objective Sleep-restriction in humans increases risk for obesity, but previous rodent studies show weight loss following sleep deprivation, possibly due to stressful-methods used to prevent sleep. Obesity-resistant (OR) rats exhibit consolidated-sleep and resistance to weight-gain. We hypothesized that sleep disruption by a less-stressful method would increase body weight, and examined effect of partial sleep deprivation (PSD) on body weight in OR and Sprague-Dawley (SD) rats. Design and Methods OR and SD rats (n=12/group) were implanted with transmitters to record sleep/wake. After baseline recording, six SD and six OR rats underwent 8 h PSD during light-phase for 9 d. Sleep was reduced using recordings of random noise. Sleep/wake states were scored as wakefulness (W), slow-wave-sleep (SWS) and rapid-eye-movement-sleep (REMS). Total number of transitions between stages, SWS-delta-power, food intake and body weight were documented. Results Exposure to noise decreased SWS and REMS time, while increasing W time. Sleep-deprivation increased number of transitions between stages and SWS-delta-power. Further, PSD during the rest phase increased recovery-sleep during active phase. The PSD SD and OR rats had greater food intake and body weight compared to controls Conclusions PSD by less-stressful means increases body weight in rats. Also, PSD during rest phase increases active period sleep. PMID:23666828

Partial sleep deprivation by environmental noise increases food intake and body weight in obesity-resistant rats.

PubMed

Mavanji, Vijayakumar; Teske, Jennifer A; Billington, Charles J; Kotz, Catherine M

2013-07-01

Sleep restriction in humans increases risk for obesity, but previous rodent studies show weight loss following sleep deprivation, possibly due to stressful methods used to prevent sleep. Obesity-resistant (OR) rats exhibit consolidated-sleep and resistance to weight gain. It was hypothesized that sleep disruption by a less-stressful method would increase body weight, and the effect of partial sleep deprivation (PSD) on body weight in OR and Sprague-Dawley (SD) rats was examined. OR and SD rats (n = 12/group) were implanted with transmitters to record sleep/wake. After baseline recording, six SD and six OR rats underwent 8 h PSD during light phase for 9 days. Sleep was reduced using recordings of random noise. Sleep/wake states were scored as wakefulness (W), slow-wave-sleep (SWS), and rapid-eye-movement-sleep (REMS). Total number of transitions between stages, SWS-delta-power, food intake, and body weight were documented. Exposure to noise decreased SWS and REMS time, while increasing W time. Sleep-deprivation increased the number of transitions between stages and SWS-delta-power. Further, PSD during the rest phase increased recovery sleep during the active phase. The PSD SD and OR rats had greater food intake and body weight compared to controls PSD by less-stressful means increases body weight in rats. Also, PSD during the rest phase increases active period sleep. Copyright © 2012 The Obesity Society.

The Relations of Sleep and Quality of Life to School Performance in Youth with Type 1 Diabetes

ERIC Educational Resources Information Center

Perfect, Michelle M.

2014-01-01

This study examined parent and youth self-reports to test the hypothesis that perceived insufficient sleep duration, inconsistent sleep habits, reduced quality of life, less frequent blood glucose monitoring, and higher hemoglobin A1c would predict poorer school functioning among 50 youth with type 1 diabetes. The data suggested that a delay in…

Sleep Can Reduce the Testing Effect: It Enhances Recall of Restudied Items but Can Leave Recall of Retrieved Items Unaffected

ERIC Educational Resources Information Center

Bäuml, Karl-Heinz T.; Holterman, Christoph; Abel, Magdalena

2014-01-01

The testing effect refers to the finding that retrieval practice in comparison to restudy of previously encoded contents can improve memory performance and reduce time-dependent forgetting. Naturally, long retention intervals include both wake and sleep delay, which can influence memory contents differently. In fact, sleep immediately after…

Good sleep quality is associated with better academic performance among Sudanese medical students.

PubMed

Mirghani, Hyder Osman; Mohammed, Osama Salih; Almurtadha, Yahia Mohamed; Ahmed, Moneir Siddig

2015-11-23

There is increasing awareness about the association of sleep quality and academic achievement among university students. However, the relationship between sleep quality and academic performance has not been examined in Sudan; this study assessed the relationship between sleep quality and academic performance among Sudanese medical students. A case-control study was conducted among 165 male and female medical students at two Sudanese universities. Excellent (A) and pass (C) academic groups were invited to respond to a self-administered questionnaire, using the Pittsburgh Sleep Quality Index (PSQI). Students also completed a diary detailing their sleep habits for 2 weeks prior to filling out the questionnaire. Various parameters of sleep quality were then compared between the two groups. A significant difference (p < 0.001) between the excellent and average groups was found for overall sleep quality, subjective sleep rating, bedtime later than midnight, sleep latency, and daytime dysfunction (during driving, preparing a meal, etc.). No differences were found between groups for the use of sleep medications. The mean sleeping hours was (7 ± 1.9) and (6.3 ± 1.9) for the excellent and pass groups respectively (p < 0.05). A significant difference (p < 0.001) between the excellent and average groups was found for weekday and weekend bedtime, weekend wake-up time, and weekend wake-up delay. No differences were found between groups for the weekday's wake- up time, and bedtime delay during weekends. Besides, snoring was present in 9.2 % of the excellent group versus 28 % in pass group (p < 0.005).

Prevalence and Correlates of Insufficient Sleep Syndrome in Japanese Young Adults: A Web-Based Cross-Sectional Study.

PubMed

Morita, Yuko; Sasai-Sakuma, Taeko; Asaoka, Shoichi; Inoue, Yuichi

2015-10-15

This study investigated the prevalence and risk factors of insufficient sleep syndrome (ISS), and factors associated with daytime dysfunction in the disorder in Japanese young adults. In this cross-sectional study, a web-based questionnaire survey was used to assess demographic variables, sleep habits and quality, depressive symptoms, and health-related quality of life (HRQOL) in 2,276 participants aged 20-25. Eleven percent of participants were classified as having ISS. Multiple logistic regression analysis revealed that the presence of ISS was significantly associated with social status (student or full-time employee). The participants with ISS had significantly higher depression scores and lower mental component summary scores than healthy sleepers. In the participants with ISS, a delayed sleep-wake schedule was extracted as a factor associated with worse mental component summary. Results indicate a relatively high proportion of Japanese young adults suffer from ISS, and that the condition is associated with a social status of student or full-time employee. Moreover, a delayed sleep-wake schedule may lead to further deterioration of mental HRQOL in ISS-affected persons. © 2015 American Academy of Sleep Medicine.

Sleep-dependent modulation of affectively guided decision-making.

PubMed

Pace-Schott, Edward F; Nave, Genevieve; Morgan, Alexandra; Spencer, Rebecca M C

2012-02-01

A question of great interest in current sleep research is whether and how sleep might facilitate complex cognitive skills such as decision-making. The Iowa Gambling Task (IGT) was used to investigate effects of sleep on affect-guided decision-making. After a brief standardized preview of the IGT that was insufficient to learn its underlying rule, participants underwent a 12-h delay containing either a normal night's sleep (Sleep group; N = 28) or continuous daytime wake (Wake group; N = 26). Following the delay, both groups performed the full IGT. To control for circadian effects, two additional groups performed both the preview and the full task either in the morning (N = 17) or the evening (N = 21). In the IGT, four decks of cards were presented. Draws from two 'advantageous decks' yielded low play-money rewards, occasional low losses and, over multiple draws, a net gain. Draws from 'disadvantageous' decks yielded high rewards, occasional high losses and, over multiple draws, a net loss. Participants were instructed to win and avoid losing as much as possible, and better performance was defined as more advantageous draws. Relative to the wake group, the sleep group showed both superior behavioral outcome (more advantageous draws) and superior rule understanding (blindly judged from statements written at task completion). Neither measure differentiated the two control groups. These results illustrate a role of sleep in optimizing decision-making, a benefit that may be brought about by changes in underlying emotional or cognitive processes. © 2011 European Sleep Research Society.

Vitamin B12 affects non-photic entrainment of circadian locomotor activity rhythms in mice.

PubMed

Ebihara, S; Mano, N; Kurono, N; Komuro, G; Yoshimura, T

1996-07-15

Administration of vitamin B12 (VB12) has been reported to normalize human sleep-wake rhythm disorders such as non-24-h sleep-wake syndrome (HNS), delayed sleep phase syndrome (DSPS) or insomnia. However, the mechanisms of the action of VB12 on the rhythm disorders are unknown. In the present study, therefore, effects of VB12 on circadian rhythms of locomotor activity were examined in mice. In the first experiment, CBA/J mice were maintained under continuous light condition (LL) or blinded, and after free-running rhythms became stable, the mice were intraperitoneally injected with either VB12 or saline at a fixed time every day. In all the mice with tau > 24 h, saline injections resulted in entrainment of circadian rhythms, whereas not all the mice with tau < 24 h entrained to the injection. In contrast to saline injections, VB12 injections did not always induce entrainment and about half of the mice with tau > 24 h free-ran during the injection. In the second experiment, the amount of phase advances of circadian rhythms induced by a single injection of saline at circadian time (CT) 11 under LL was compared between the mice with and without VB12 silastic tubes. The results showed that the amplitude of phase advances was smaller in the mice with VB12 than those without VB12. In the third experiment, daily injections of saline were given to the mice with VB12 silastic tubes maintained under LL. In this chronic treatment of VB12 as well, attenuating effects of VB12 on saline-induced entrainment were observed. These results suggest that VB12 affects the mechanisms implicated in non-photic entrainment of circadian rhythms in mice.

Long working hours and sleep disturbances: the Whitehall II prospective cohort study.

PubMed

Virtanen, Marianna; Ferrie, Jane E; Gimeno, David; Vahtera, Jussi; Elovainio, Marko; Singh-Manoux, Archana; Marmot, Michael G; Kivimäki, Mika

2009-06-01

To examine whether exposure to long working hours predicts various forms of sleep disturbance; short sleep, difficulty falling asleep, frequent waking, early waking and waking without feeling refreshed. Prospective study with 2 measurements of working hours (phase 3, 1991-1994 and phase 5, 1997-1999) and 2 measurements of subjective sleep disturbances (phase 5 and phase 7, 2002-2004). The Whitehall II study of British civil servants. Full time workers free of sleep disturbances at phase 5 and employed at phases 5 and 7 (n = 937-1594) or at phases 3, 5, and 7 (n = 886-1510). Working more than 55 hours a week, compared with working 35-40 hours a week, was related to incident sleep disturbances; demographics-adjusted odds ratio (95% CI) 1.98 (1.05, 3.76) for shortened sleeping hours, 3.68 (1.58, 8.58) for difficulty falling asleep; and 1.98 (1.04, 3.77) for waking without feeling refreshed. Repeat exposure to long working hours was associated with odds ratio 3.24 (1.45, 7.27) for shortened sleep, 6.66 (2.64, 16.83) for difficulty falling asleep, and 2.23 (1.16, 4.31) for early morning awakenings. Some associations were attenuated after adjustment for other risk factors. To a great extent, similar results were obtained using working hours as a continuous variable. Imputation of missing values supported the findings on shortened sleep and difficulty in falling asleep. Working long hours appears to be a risk factor for the development of shortened sleeping hours and difficulty falling asleep.

Relative phase of oscillations of cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations during sleep

NASA Astrophysics Data System (ADS)

Pierro, Michele L.; Sassaroli, Angelo; Bergethon, Peter R.; Fantini, Sergio

2012-02-01

We present a near-infrared spectroscopy study of the instantaneous phase difference between spontaneous oscillations of cerebral deoxy-hemoglobin and oxy-hemoglobin concentrations ([Hb] and [HbO], respectively) in the low-frequency range, namely 0.04-0.12 Hz. We report phase measurements during the transitions between different sleep stages in a whole-night study of a human subject. We have found that the phase difference between [Hb] and [HbO] low-frequency oscillations tends to be greater in deep sleep (by ~96° on average) and REM sleep (by ~77° on average) compared to the awake state. In particular, we have observed progressive phase increases as the subject transitions from awake conditions into non-REM sleep stages N1, N2, and N3. Corresponding phase decreases were recorded in the reversed transitions from sleep stages N3 to N2, and N2 to awake. These results illustrate the physiological information content of phase measurements of [Hb] and [HbO] oscillations that reflect the different cerebral hemodynamic conditions of the different sleep stages, and that can find broader applicability in a wide range of near-infrared spectroscopy brain studies.

Youth Screen Media Habits and Sleep: Sleep-Friendly Screen Behavior Recommendations for Clinicians, Educators, and Parents.

PubMed

Hale, Lauren; Kirschen, Gregory W; LeBourgeois, Monique K; Gradisar, Michael; Garrison, Michelle M; Montgomery-Downs, Hawley; Kirschen, Howard; McHale, Susan M; Chang, Anne-Marie; Buxton, Orfeu M

2018-04-01

With the widespread use of portable electronic devices and the normalization of screen media devices in the bedroom, insufficient sleep has become commonplace. In a recent literature review, 90% of included studies found an association between screen media use and delayed bedtime and/or decreased total sleep time. This pervasive phenomenon of pediatric sleep loss has widespread implications. There is a need for basic, translational, and clinical research examining the effects of screen media on sleep loss and health consequences in children and adolescents to educate and motivate clinicians, teachers, parents and youth themselves to foster healthy sleep habits. Copyright © 2017 Elsevier Inc. All rights reserved.

Sleep, sleepiness, and circadian rhythmicity in aircrews operating on transatlantic routes

NASA Technical Reports Server (NTRS)

Wegmann, Hans M.; Gundel, Alexander; Samel, Alexander; Schwartz, Edwin; Naumann, Martin

1986-01-01

A two-phase study was performed on B-747 crew members operating on regular passenger flights with 9-h time difference. In phase I, sleep-log surveys were obtained. The results for the layover period indicate congruent sleep patterns with shifts in sleep onset less than 9 h; sleep duration was prolonged. Phase II consisted of polygraphic sleep recordings and multiple sleep latency tests (MSLTs) applied to four cockpit crews in a baseline period, during the layover, and after return to home base. During the layover, mean bed times were shifted by about 4.5 h, and sleep was disturbed by early and prolonged awakenings which led to a reduction of sleep efficiency. The ECG and rectal temperature recordings gave evidence for a desynchronization of the circadian system and an internal dissociation of different body functions.

Human daily rhythms measured for one year.

PubMed

Binkley, S; Tome, M B; Crawford, D; Mosher, K

1990-08-01

Four human subjects recorded their wake-up and to-sleep times for one year each. The data were plotted to display individual circadian rhythms and the data were analyzed statistically. First, individuals had characteristic patterns in which visible changes in the patterns were observed mainly when time zones were changed because of travel. Second, the months with the latest wake-up and latest to-sleep times concentrated around the winter solstice; the months with the earliest wake-up and earliest to-sleep times concentrated around the fall equinox. Third, new moon versus full moon days were not different. Fourth, one-hour changes between standard and daylight savings time in the USA were reflected by near one-hour changes in two subjects, but not in a third. Fifth, weekend delays in wake-up time (0.8-1.6 hours), weekend delays in to-sleep time (0.1-0.5 hours), and shorter weekend awake time (0.8-1.3 hours) were observed. Sixth, throughout the year, wake-up times were close to the time of sunrise, but to-sleep times were several hours past sunset.

Auditory closed-loop stimulation of the sleep slow oscillation enhances memory.

PubMed

Ngo, Hong-Viet V; Martinetz, Thomas; Born, Jan; Mölle, Matthias

2013-05-08

Brain rhythms regulate information processing in different states to enable learning and memory formation. The <1 Hz sleep slow oscillation hallmarks slow-wave sleep and is critical to memory consolidation. Here we show in sleeping humans that auditory stimulation in phase with the ongoing rhythmic occurrence of slow oscillation up states profoundly enhances the slow oscillation rhythm, phase-coupled spindle activity, and, consequently, the consolidation of declarative memory. Stimulation out of phase with the ongoing slow oscillation rhythm remained ineffective. Closed-loop in-phase stimulation provides a straight-forward tool to enhance sleep rhythms and their functional efficacy. Copyright © 2013 Elsevier Inc. All rights reserved.

Sleep measurement and monitoring in children with Down syndrome: A review of the literature, 1960–2010

PubMed Central

Churchill, Shervin S.; Kieckhefer, Gail M.; Landis, Carol A.; Ward, Teresa M.

2012-01-01

SUMMARY Children with Down syndrome (DS) are at risk for sleep disturbances due to the anatomical features of the syndrome. Over the past 50 years research studies have measured sleep in children with DS to characterize sleep architecture and its relation to developmental delay. In the 1980s sleep disordered breathing (SDB) was recognized as a major cause of sleep disturbance in DS. The aim of this comprehensive review is to synthesize studies and present the historical context of evolving technologies, methodologies, and knowledge about SDB and DS. Future research opportunities and practice implications are discussed. PMID:22410159

Selected sleep disorders: restless legs syndrome and periodic limb movement disorder, sleep apnea syndrome, and narcolepsy.

PubMed

Erman, Milton K

2006-12-01

Sleep disorders, including restless legs syndrome and periodic limb movement disorder, sleep apnea syndrome, and narcolepsy, are prevalent medical conditions, likely to be seen by practicing psychiatrists. Awareness of these conditions and their presentations, pathophysiology, and treatment allows psychiatrists to treat these conditions where appropriate, to minimize complications and health consequences associated with delayed diagnosis, and to reduce the burden of disease that these conditions may place on patients already experiencing primary psychiatric disorders.

Sleep and Premenstrual Syndrome

PubMed Central

Jehan, Shazia; Auguste, Evan; Hussain, Mahjabeen; Pandi-Perumal, Seithikurippu R.; Brzezinski, Amon; Gupta, Ravi; Attarian, Hrayr; Jean-Louis, Giradin; McFarlane, Samy I.

2016-01-01

The etiology of premenstrual syndrome (PMS) is unknown; it may be due to the normal effect of hormones during the menstrual cycle as it occurs in the late luteal phase of the menstrual cycle.PMS affects women of childbearing age and remits with the onset of menstruation. The menstrual phase is known to influence stage 2 and REM sleep in women, irrespective of premenstrual dysphoric disorder (PMDD). Women with PMDD showed a decreased response to melatonin in their luteal phase as compared to the follicular phase of the menstrual cycle. However, melatonin duration or timing of offset in the morning has not been reported to correlate with the mood. Rather, improvement in mood-related symptoms of PMDD has been found to be influenced by sleep deprivation, be it sleep restrictions in early or late night. Sleep disturbance and decreased melatonin secretions due to hormonal fluctuations during the luteal phase of the menstrual cycle could explain the sleep complaints of PMDD. PMID:28239684

Donepezil Improves Episodic Memory in Young Individuals Vulnerable to the Effects of Sleep Deprivation

PubMed Central

Chuah, Lisa Y.M.; Chong, Delise L.; Chen, Annette K.; Rekshan, William R.; Tan, Jiat-Chow; Zheng, Hui; Chee, Michael W.L.

2009-01-01

Study Objectives: We investigated if donepezil, a long-acting orally administered cholinesterase inhibitor, would reduce episodic memory deficits associated with 24 h of sleep deprivation. Design: Double-blind, placebo-controlled, crossover study involving 7 laboratory visits over 2 months. Participants underwent 4 functional MRI scans; 2 sessions (donepezil or placebo) followed a normal night's sleep, and 2 sessions followed a night of sleep deprivation. Setting: The study took place in a research laboratory. Participants: 26 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders. Interventions: 5 mg of donepezil was taken once daily for approximately 17 days. Measurements and Results: Subjects were scanned while performing a semantic judgment task and tested for word recognition outside the scanner 45 minutes later. Sleep deprivation increased the frequency of non-responses at encoding and impaired delayed recognition. No benefit of donepezil was evident when participants were well rested. When sleep deprived, individuals who showed greater performance decline improved with donepezil, whereas more resistant individuals did not benefit. Accompanying these behavioral effects, there was corresponding modulation of task-related activation in functionally relevant brain regions. Brain regions identified in relation to donepezil-induced alteration in non-response rates could be distinguished from regions relating to improved recognition memory. This suggests that donepezil can improve delayed recognition in sleep-deprived persons by improving attention as well as enhancing memory encoding. Conclusions: Donepezil reduced decline in recognition performance in individuals vulnerable to the effects of sleep deprivation. Additionally, our findings demonstrate the utility of combined fMRI–behavior evaluation in psychopharmacological studies. Citation: Chuah LYM; Chong DL; Chen AK; Rekshan WR; Tan JC; Zheng H; Chee MWL. Donepezil improves episodic memory in young individuals vulnerable to the effects of sleep deprivation. SLEEP 2009;32(8):999-1010. PMID:19725251

Environmental Radiofrequency Electromagnetic Fields Exposure at Home, Mobile and Cordless Phone Use, and Sleep Problems in 7-Year-Old Children

PubMed Central

Huss, Anke; van Eijsden, Manon; Guxens, Monica; Beekhuizen, Johan; van Strien, Rob; Kromhout, Hans; Vrijkotte, Tania; Vermeulen, Roel

2015-01-01

Background We evaluated if exposure to RF-EMF was associated with reported quality of sleep in 2,361 children, aged 7 years. Methods This study was embedded in the Amsterdam Born Children and their Development (ABCD) birth cohort study. When children were about five years old, school and residential exposure to RF-EMF from base stations was assessed with a geospatial model (NISMap) and from indoor sources (cordless phone/WiFi) using parental self-reports. Parents also reported their children’s use of mobile or cordless phones. When children were seven years old, we evaluated sleep quality as measured with the Child Sleep Habits Questionnaire (CSHQ) filled in by parents. Of eight CSHQ subscales, we evaluated sleep onset delay, sleep duration, night wakenings, parasomnias and daytime sleepiness with logistic or negative binomial regression models, adjusting for child’s age and sex and indicators of socio-economic position of the parents. We evaluated the remaining three subscales (bedtime resistance, sleep anxiety, sleep disordered breathing) as unrelated outcomes (negative control) because these were a priori hypothesised not to be associated with RF-EMF. Results Sleep onset delay, night wakenings, parasomnias and daytime sleepiness were not associated with residential exposure to RF-EMF from base stations. Sleep duration scores were associated with RF-EMF levels from base stations. Higher use mobile phones was associated with less favourable sleep duration, night wakenings and parasomnias, and also with bedtime resistance. Cordless phone use was not related to any of the sleeping scores. Conclusion Given the different results across the evaluated RF-EMF exposure sources and the observed association between mobile phone use and the negative control sleep scale, our study does not support the hypothesis that it is the exposure to RF-EMF that is detrimental to sleep quality in 7-year old children, but potentially other factors that are related to mobile phone usage. PMID:26509676

The Association Between Anxiety Symptoms and Sleep in School-Aged Children: A Combined Insight From the Children's Sleep Habits Questionnaire and Actigraphy.

PubMed

Fletcher, Fay E; Conduit, Russell; Foster-Owens, Mistral D; Rinehart, Nicole J; Rajaratnam, Shantha M W; Cornish, Kim M

2018-01-01

The current study assessed the association between anxiety symptoms and sleep in 90 school-aged children, aged 6-12 years (M age = 108 months, 52.2% male). The Children's Sleep Habits Questionnaire (CSHQ) and 14 nights of actigraphy were used to assess sleep. Anxiety was assessed using the Spence Children's Anxiety Scale (SCAS). A significant association was found between parent-reported anxiety symptoms and current sleep problems (i.e., CSHQ total scores ≥ 41). An examination of SCAS subscales identified a specific association between generalized anxiety disorder (GAD) symptoms and increased parental sleep concerns, including sleep onset delay, sleep duration, and daytime sleepiness. Regarding actigraphy, whilst anxiety was not associated with average sleep variables, a relationship was identified between anxiety and the night-to-night variability of actigraphy-derived sleep schedules.

Non-contact assessment of obstructive sleep apnea cardiovascular biomarkers using photoplethysmography imaging

NASA Astrophysics Data System (ADS)

Amelard, Robert; Pfisterer, Kaylen J.; Jagani, Shubh; Clausi, David A.; Wong, Alexander

2018-02-01

Obstructive sleep apnea (OSA) affects 20% of the adult population, and is associated with cardiovascular and cognitive morbidities. However, it is estimated that up to 80% of treatable OSA cases remain undiagnosed. Cur- rent methods for diagnosing OSA are expensive, labor-intensive, and involve uncomfortable wearable sensors. This study explored the feasibility of non-contact biophotonic assessment of OSA cardiovascular biomarkers via photoplethysmography imaging (PPGI). In particular, PPGI was used to monitor the hemodynamic response to obstructive respiratory events. Sleep apnea onset was simulated using Muller's maneuver in which breathing was obstructed by a respiratory clamp. A custom PPGI system, coded hemodynamic imaging (CHI), was positioned 1 m above the bed and illuminated the participant's head with 850 nm light, providing non-intrusive illumination for night-time monitoring. A video was recorded before, during and following an apnea event at 60 fps, yielding 17 ms temporal resolution. Per-pixel absorbance signals were extracted using a Beer-Lambert derived light transport model, and subsequently denoised. The extracted hemodynamic signal exhibited dynamic temporal modulation during and following the apnea event. In particular, the pulse wave amplitude (PWA) decreased during obstructed breathing, indicating vasoconstriction. Upon successful inhalation, the PWA gradually increased toward homeostasis following a temporal phase delay. This temporal vascular tone modulation provides insight into autonomic and vascular response, and may be used to assess sleep apnea using non-contact biophotonic imaging.

Community partnership for healthy sleep: Research protocol.

PubMed

Redeker, Nancy S; Ordway, Monica R; Banasiak, Nancy; Caldwell, Barbara; Canapari, Craig; Crowley, Angela; Fenick, Ada; Jeon, Sangchoon; O'Connell, Meghan; Sude, Leslie; Sadler, Lois S

2018-02-01

Beginning early in life, sleep health, including adequate quality, quantity, and consistent sleep routines, is critical to growth and development, behavior, and mental and physical health. Children who live in economically stressed urban environments are at particular risk for sleep deficiency and its negative consequences. Although efficacious sleep health interventions are available, few address the context of economically stressed urban environments. The purpose of this paper is to describe a two-phase protocol for an ongoing NIH/NINR-funded community-engaged study designed to understand the perspectives of parents, community child care and pediatric health care providers about sleep habits, factors that contribute to sleep and sleep habits, sleep difficulty, and potentially useful sleep promotion strategies among children living in economically stressed urban environments. The social-ecological model guides this study. Phase I employs a convergent mixed-methods design, in which we are conducting semi-structured interviews with parents, childcare providers, and primary health care providers. We are collecting 9 days of objective sleep data (wrist actigraphy) from children who are 6-18 months (n = 15) and 19-36 months of age (n = 15) and parent reports of sleep and sleep-related factors using standard questionnaires. In Phase I, we will use a qualitative descriptive approach to analyze the interview data, and descriptive statistics to analyze the survey and actigraph data. In Phase II, we will use the information to develop a contextually relevant program to promote sleep health. Our long-term goal is to improve sleep health and sleep-related outcomes in these children. © 2017 Wiley Periodicals, Inc.

Sleep supports cued fear extinction memory consolidation independent of circadian phase.

PubMed

Melo, Irene; Ehrlich, Ingrid

2016-07-01

Sleep promotes memory, particularly for declarative learning. However, its role in non-declarative, emotional memories is less well understood. Some studies suggest that sleep may influence fear-related memories, and thus may be an important factor determining the outcome of treatments for emotional disorders such as post-traumatic stress disorder. Here, we investigated the effect of sleep deprivation and time of day on fear extinction memory consolidation. Mice were subjected to a cued Pavlovian fear and extinction paradigm at the beginning of their resting or active phase. Immediate post-extinction learning sleep deprivation for 5h compromised extinction memory when tested 24h after learning. Context-dependent extinction memory recall was completely prevented by sleep-manipulation during the resting phase, while impairment was milder during the active phase and extinction memory retained its context-specificity. Importantly, control experiments excluded confounding factors such as differences in baseline locomotion, fear generalization and stress hormone levels. Together, our findings indicate that post-learning sleep supports cued fear extinction memory consolidation in both circadian phases. The lack of correlation between memory efficacy and sleep time suggests that extinction memory may be influenced by specific sleep events in the early consolidation period. Copyright © 2016 Elsevier Inc. All rights reserved.

Association of evening smartphone use with cardiac autonomic nervous activity after awakening in adolescents living in high school dormitories.

PubMed

Nose, Yoko; Fujinaga, Rina; Suzuki, Maki; Hayashi, Ikuyo; Moritani, Toshio; Kotani, Kazuhiko; Nagai, Narumi

2017-04-01

Smartphones are prevalently used among adolescents; however, nighttime exposure to blue-enriched light, through electric devices, is known to induce delays of the circadian rhythm phases and poor morning somatic conditions. We therefore investigated whether evening smartphone use may affect sleep-wake cycle and cardiac autonomic nervous system (ANS) activity after awaking in dormitory students. The participants were high school students, living under dormitory rules regarding the curfew, study, meals, lights-out, and wake-up times. The students were forbidden from the use of both television and personal computer in their private rooms, and only the use of a smartphone was permitted. According to prior assessment of smartphone use, we chose age-, sex-, exercise time-matched long (n = 22, >120 min) and short (n = 14, ≤60 min) groups and compared sleep-wake cycle and physiological parameters, such as cardiac ANS activity, blood pressure, and intra-aural temperature. All measurements were performed during 6:30 to 7:00 a.m. in the dormitories. Compared with the short group, the long group showed a significantly lower cardiac ANS activity (2727 ± 308 vs. 4455 ± 667 ms 2 , p = 0.030) with a tendency toward a high heart rate, in addition to later bedtimes during weekdays and more delayed wake-up times over the weekend. Blood pressure and intra-aural temperature did not differ between the groups. In this population, evening smartphone use may be associated with altered sleep-wake cycle and a diminished cardiac ANS activity after awakening could be affecting daytime activities.

Polymorphism in the PER3 promoter associates with diurnal preference and delayed sleep phase disorder.

PubMed

Archer, Simon N; Carpen, Jayshan D; Gibson, Mark; Lim, Gim Hui; Johnston, Jonathan D; Skene, Debra J; von Schantz, Malcolm

2010-05-01

To screen the PER3 promoter for polymorphisms and investigate the phenotypic associations of these polymorphisms with diurnal preference, delayed sleep phase disorder/syndrome (DSPD/DSPS), and their effects on reporter gene expression. Interspecific comparison was used to define the approximate extent of the PER3 promoter as the region between the transcriptional start site and nucleotide position -874. This region was screened in DNA pools using PCR and direct sequencing, which was also used to screen DNA from individual participants. The different promoter alleles were cloned into a luciferase expression vector and a deletion library created. Promoter activation was measured by chemiluminescence. N/A. DNA samples were obtained from volunteers with defined diurnal preference (3 x 80, selected from a pool of 1,590), and DSPD patients (n=23). N/A. We verified three single nucleotide polymorphisms (G -320T, C -319A, G -294A), and found a novel variable number tandem repeat (VNTR) polymorphism (-318 1/2 VNTR). The -320T and -319A alleles occurred more frequently in DSPD compared to morning (P = 0.042 for each) or evening types (P = 0.006 and 0.033). The allele combination TA2G was more prevalent in DSPD compared to morning (P 0.033) or evening types (P = 0.002). Luciferase expression driven by the TA2G combination was greater than for the more common GC2A (P < 0.05) and the rarer TA1G (P < 0.001) combinations. Deletion reporter constructs identified two enhancer regions (-703 to -605, and -283 to -80). Polymorphisms in the PER3 promoter could affect its expression, leading to potential differences in the observed functions of PER3.

The effects of self-selected light-dark cycles and social constraints on human sleep and circadian timing: a modeling approach

PubMed Central

Skeldon, Anne C.; Phillips, Andrew J. K.; Dijk, Derk-Jan

2017-01-01

Why do we go to sleep late and struggle to wake up on time? Historically, light-dark cycles were dictated by the solar day, but now humans can extend light exposure by switching on artificial lights. We use a mathematical model incorporating effects of light, circadian rhythmicity and sleep homeostasis to provide a quantitative theoretical framework to understand effects of modern patterns of light consumption on the human circadian system. The model shows that without artificial light humans wakeup at dawn. Artificial light delays circadian rhythmicity and preferred sleep timing and compromises synchronisation to the solar day when wake-times are not enforced. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity (‘social jet-lag’). The model implies that developmental changes in sleep homeostasis and circadian amplitude make adolescents particularly sensitive to effects of light consumption. The model predicts that ameliorating social jet-lag is more effectively achieved by reducing evening light consumption than by delaying social constraints, particularly in individuals with slow circadian clocks or when imposed wake-times occur after sunrise. These theory-informed predictions may aid design of interventions to prevent and treat circadian rhythm-sleep disorders and social jet-lag. PMID:28345624

Exposure to bright light modifies HRV responses to mental tasks during nocturnal sleep deprivation.

PubMed

Yokoi, Mari; Aoki, Ken; Shimomura, Yoshihiro; Iwanaga, Koichi; Katsuura, Tetsuo

2006-03-01

This study was intended to determine the effects of continuous bright light exposure on cardiovascular responses, particularly heart rate variability (HRV), at rest and during performance of mental tasks with acute nocturnal sleep deprivation. Eight healthy male subjects stayed awake from 21.00 to 04.30 hours under bright (BL, 2800 lux) or dim (DL, 120 lux) light conditions. During sleep deprivation, mental tasks (Stroop color-word conflict test: CWT) were performed for 15 min each hour. Blood pressure, electrocardiogram, respiratory rate, urinary melatonin concentrations and rectal temperature were measured. During sleep deprivation, BL exposure depressed melatonin secretion in comparison to DL conditions. During sleep deprivation, exposure to BL delayed the decline in heart rate (HR) for 4 h in resting periods. A significant increment of HR induced by each CWT was detected, especially at 03.00 h and later, under DL conditions only. In addition, at 04.00 h, an index of sympathetic activity and sympatho-vagal balance on HRV during CWT increased significantly under DL conditions. In contrast, an index of parasympathetic activity during CWT decreased significantly under DL conditions. However, the indexes of HRV during CWT did not change throughout sleep deprivation under BL conditions. Our results suggest that BL exposure not only delays the nocturnal decrease in HR at rest but also maintains HR and balance of cardiac autonomic modulation to mental tasks during nocturnal sleep deprivation.

Sleep, School Performance, and a School-Based Intervention among School-Aged Children: A Sleep Series Study in China

PubMed Central

Li, Shenghui; Arguelles, Lester; Jiang, Fan; Chen, Wenjuan; Jin, Xingming; Yan, Chonghuai; Tian, Ying; Hong, Xiumei; Qian, Ceng; Zhang, Jun; Wang, Xiaobin; Shen, Xiaoming

2013-01-01

Background Sufficient sleep during childhood is essential to ensure a transition into a healthy adulthood. However, chronic sleep loss continues to increase worldwide. In this context, it is imperative to make sleep a high-priority and take action to promote sleep health among children. The present series of studies aimed to shed light on sleep patterns, on the longitudinal association of sleep with school performance, and on practical intervention strategy for Chinese school-aged children. Methods and Findings A serial sleep researches, including a national cross-sectional survey, a prospective cohort study, and a school-based sleep intervention, were conducted in China from November 2005 through December 2009. The national cross-sectional survey was conducted in 8 cities and a random sample of 20,778 children aged 9.0±1.61 years participated in the survey. The five-year prospective cohort study included 612 children aged 6.8±0.31 years. The comparative cross-sectional study (baseline: n = 525, aged 10.80±0.41; post-intervention follow-up: n = 553, aged 10.81±0.33) was undertaken in 6 primary schools in Shanghai. A battery of parent and teacher reported questionnaires were used to collect information on children’s sleep behaviors, school performance, and sociodemographic characteristics. The mean sleep duration was 9.35±0.77 hours. The prevalence of daytime sleepiness was 64.4% (sometimes: 37.50%; frequently: 26.94%). Daytime sleepiness was significantly associated with impaired attention, learning motivation, and particularly, academic achievement. By contrast, short sleep duration only related to impaired academic achievement. After delaying school start time 30 minutes and 60 minutes, respectively, sleep duration correspondingly increased by 15.6 minutes and 22.8 minutes, respectively. Moreover, intervention significantly improved the sleep duration and daytime sleepiness. Conclusions Insufficient sleep and daytime sleepiness commonly existed and positively associated with the impairment of school performance, especially academic achievement, among Chinese school-aged children. The effectiveness of delaying school staring time emphasized the benefits of optimal school schedule regulation to children’s sleep health. PMID:23874468

Sleep, school performance, and a school-based intervention among school-aged children: a sleep series study in China.

PubMed

Li, Shenghui; Arguelles, Lester; Jiang, Fan; Chen, Wenjuan; Jin, Xingming; Yan, Chonghuai; Tian, Ying; Hong, Xiumei; Qian, Ceng; Zhang, Jun; Wang, Xiaobin; Shen, Xiaoming

2013-01-01

Sufficient sleep during childhood is essential to ensure a transition into a healthy adulthood. However, chronic sleep loss continues to increase worldwide. In this context, it is imperative to make sleep a high-priority and take action to promote sleep health among children. The present series of studies aimed to shed light on sleep patterns, on the longitudinal association of sleep with school performance, and on practical intervention strategy for Chinese school-aged children. A serial sleep researches, including a national cross-sectional survey, a prospective cohort study, and a school-based sleep intervention, were conducted in China from November 2005 through December 2009. The national cross-sectional survey was conducted in 8 cities and a random sample of 20,778 children aged 9.0±1.61 years participated in the survey. The five-year prospective cohort study included 612 children aged 6.8±0.31 years. The comparative cross-sectional study (baseline: n = 525, aged 10.80±0.41; post-intervention follow-up: n = 553, aged 10.81±0.33) was undertaken in 6 primary schools in Shanghai. A battery of parent and teacher reported questionnaires were used to collect information on children's sleep behaviors, school performance, and sociodemographic characteristics. The mean sleep duration was 9.35±0.77 hours. The prevalence of daytime sleepiness was 64.4% (sometimes: 37.50%; frequently: 26.94%). Daytime sleepiness was significantly associated with impaired attention, learning motivation, and particularly, academic achievement. By contrast, short sleep duration only related to impaired academic achievement. After delaying school start time 30 minutes and 60 minutes, respectively, sleep duration correspondingly increased by 15.6 minutes and 22.8 minutes, respectively. Moreover, intervention significantly improved the sleep duration and daytime sleepiness. Insufficient sleep and daytime sleepiness commonly existed and positively associated with the impairment of school performance, especially academic achievement, among Chinese school-aged children. The effectiveness of delaying school staring time emphasized the benefits of optimal school schedule regulation to children's sleep health.

Donepezil improves episodic memory in young individuals vulnerable to the effects of sleep deprivation.

PubMed

Chuah, Lisa Y M; Chong, Delise L; Chen, Annette K; Rekshan, William R; Tan, Jiat-Chow; Zheng, Hui; Chee, Michael W L

2009-08-01

We investigated if donepezil, a long-acting orally administered cholinesterase inhibitor, would reduce episodic memory deficits associated with 24 h of sleep deprivation. Double-blind, placebo-controlled, crossover study involving 7 laboratory visits over 2 months. Participants underwent 4 functional MRI scans; 2 sessions (donepezil or placebo) followed a normal night's sleep, and 2 sessions followed a night of sleep deprivation. The study took place in a research laboratory. 26 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders. 5 mg of donepezil was taken once daily for approximately 17 days. Subjects were scanned while performing a semantic judgment task and tested for word recognition outside the scanner 45 minutes later. Sleep deprivation increased the frequency of non-responses at encoding and impaired delayed recognition. No benefit of donepezil was evident when participants were well rested. When sleep deprived, individuals who showed greater performance decline improved with donepezil, whereas more resistant individuals did not benefit. Accompanying these behavioral effects, there was corresponding modulation of task-related activation in functionally relevant brain regions. Brain regions identified in relation to donepezil-induced alteration in non-response rates could be distinguished from regions relating to improved recognition memory. This suggests that donepezil can improve delayed recognition in sleep-deprived persons by improving attention as well as enhancing memory encoding. Donepezil reduced decline in recognition performance in individuals vulnerable to the effects of sleep deprivation. Additionally, our findings demonstrate the utility of combined fMRI-behavior evaluation in psychopharmacological studies.

Termination of short term melatonin treatment in children with delayed Dim Light Melatonin Onset: effects on sleep, health, behavior problems, and parenting stress.

PubMed

van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

2011-10-01

To investigate the effects of termination of short term melatonin treatment on sleep, health, behavior, and parenting stress in children with delayed Dim Light Melatonin Onset. Forty-one children (24 boys, 17 girls; mean age=9.43 years) entered melatonin treatment for 3 weeks and then discontinued treatment by first taking a half dose for 1 week and then stopping completely for another week. Sleep was measured with sleep diaries filled in by parents and with actometers worn by children. Analyses were conducted with linear mixed models. Sleep latency was longer during the stop week compared to the treatment weeks. Sleep start was later and actual sleep time was shorter during the half dose and stop weeks compared to the treatment weeks. Sleep efficiency deteriorated in the stop week. Dim Light Melatonin Onset was earlier after treatment, but this effect disappeared after the stop week. In addition to the effects on sleep, results from questionnaires completed by parents showed that melatonin treatment also had positive effects on children's health and behavior problems and parenting stress. While health deteriorated after treatment discontinuation, the effects on behavior problems and parenting stress remained. Behavior problems at baseline did not influence the effect of melatonin treatment. This study showed that complete termination of treatment after 4 weeks of melatonin use was too early. However, clinicians may advise a lower dose after a successful treatment trial of several weeks. Copyright © 2011 Elsevier B.V. All rights reserved.

Estimating dim light melatonin onset (DLMO) phase in adolescents using summer or school-year sleep/wake schedules.

PubMed

Crowley, Stephanie J; Acebo, Christine; Fallone, Gahan; Carskadon, Mary A

2006-12-01

This analysis examined associations between the salivary dim light melatonin onset (DLMO) phase and self-selected sleep/ wake schedules in groups of children and adolescents during summer vacation and during the school year to determine the degree to which sleep/wake patterns can estimate salivary DLMO phase. Participants slept at home on self-selected schedules for 5 consecutive nights and reported their bedtime and wake-up time via daily telephone messages. Salivary melatonin was sampled in the laboratory on one evening every 30 minutes in dim light (< 50 lux) to determine DLMO phase. Within group bivariate regressions between sleep pattern measures (bedtime, wake-up time, and midsleep time) and DLMO phase were computed. One group, ages 9 to 17 years (mean age = 12.5, SD = 2.3 years, 74 males, 75 females) contributed 149 DLMO phase and sleep/wake pattern measures while on a school year schedule ("school group"). A separate group, ages 9 to 16 years (mean age = 13.1, SD = 1.3 years, 30 males, 29 females) contributed 59 DLMO phase and sleep/wake pattern measures while on a summer schedule ("summer group"). Bedtime, midsleep time, and wake-up time were positively correlated with DLMO phase in both groups. Although all correlation coefficients for the summer group were statistically greater compared to the school group, the regression equations predicted DLMO phase within +/- 1 hour of the measured DLMO phase in approximately 80% for both groups. DLMO phase can be estimated using self-selected sleep/wake patterns during the school year or summer vacation in healthy children and adolescents.

Delayed benefit of naps on motor learning in preschool children.

PubMed

Desrochers, Phillip C; Kurdziel, Laura B F; Spencer, Rebecca M C

2016-03-01

Sleep benefits memory consolidation across a variety of domains in young adults. However, while declarative memories benefit from sleep in young children, such improvements are not consistently seen for procedural skill learning. Here we examined whether performance improvements on a procedural task, although not immediately observed, are evident after a longer delay when augmented by overnight sleep (24 h after learning). We trained 47 children, aged 33-71 months, on a serial reaction time task and, using a within-subject design, evaluated performance at three time points: immediately after learning, after a daytime nap (nap condition) or equivalent wake opportunity (wake condition), and 24 h after learning. Consistent with previous studies, performance improvements following the nap did not differ from performance improvements following an equivalent interval spent awake. However, significant benefits of the nap were found when performance was assessed 24 h after learning. This research demonstrates that motor skill learning is benefited by sleep, but that this benefit is only evident after an extended period of time.

Short-Term Sleep Disturbance-Induced Stress Does not Affect Basal Pain Perception, but Does Delay Postsurgical Pain Recovery.

PubMed

Wang, Po-Kai; Cao, Jing; Wang, Hongzhen; Liang, Lingli; Zhang, Jun; Lutz, Brianna Marie; Shieh, Kun-Ruey; Bekker, Alex; Tao, Yuan-Xiang

2015-11-01

Chronic sleep disturbance-induced stress is known to increase basal pain sensitivity. However, most surgical patients frequently report short-term sleep disturbance/deprivation during the pre- and postoperation periods and have normal pain perception presurgery. Whether this short-term sleep disturbance affects postsurgical pain is elusive. Here, we report that pre- or postexposure to rapid eye movement sleep disturbance (REMSD) for 6 hours daily for 3 consecutive days did not alter basal responses to mechanical, heat, and cold stimuli, but did delay recovery in incision-induced reductions in paw withdrawal threshold to mechanical stimulation and paw withdrawal latencies to heat and cold stimuli on the ipsilateral side of male or female rats. This short-term REMSD led to stress shown by an increase in swim immobility time, a decrease in sucrose consumption, and an increase in the level of corticosterone in serum. Blocking this stress via intrathecal RU38486 or bilateral adrenalectomy abolished REMSD-caused delay in recovery of incision-induced reductions in behavioral responses to mechanical, heat, and cold stimuli. Moreover, this short-term REMSD produced significant reductions in the levels of mu opioid receptor and kappa opioid receptor, but not Kv1.2, in the ipsilateral L4/5 spinal cord and dorsal root ganglia on day 9 after incision (but not after sham surgery). Our findings show that short-term sleep disturbance either pre- or postsurgery does not alter basal pain perception, but does exacerbate postsurgical pain hypersensitivity. The latter may be related to the reductions of mu and kappa opioid receptors in the spinal cord and dorsal root ganglia caused by REMSD plus incision. Prevention of short-term sleep disturbance may help recovery from postsurgical pain in patients. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Telemetric Study of Sleep Architecture and Sleep Homeostasis in the Day-Active Tree Shrew Tupaia belangeri

PubMed Central

Coolen, Alex; Hoffmann, Kerstin; Barf, R. Paulien; Fuchs, Eberhard; Meerlo, Peter

2012-01-01

Study Objectives: In this study the authors characterized sleep architecture and sleep homeostasis in the tree shrew, Tupaia belangeri, a small, omnivorous, day-active mammal that is closely related to primates. Design: Adult tree shrews were individually housed under a 12-hr light/12-hr dark cycle in large cages containing tree branches and a nest box. The animals were equipped with radio transmitters to allow continuous recording of electroencephalogram (EEG), electromyogram (EMG), and body temperature without restricting their movements. Recordings were performed under baseline conditions and after sleep deprivation (SD) for 6 hr or 12 hr during the dark phase. Measurements and Results: Under baseline conditions, the tree shrews spent a total of 62.4 ± 1.4% of the 24-hr cycle asleep, with 91.2 ± 0.7% of sleep during the dark phase and 33.7 ± 2.8% sleep during the light phase. During the dark phase, all sleep occurred in the nest box; 79.6% of it was non-rapid eye movement (NREM) sleep and 20.4% was rapid eye movement (REM) sleep. In contrast, during the light phase, sleep occurred almost exclusively on the top branches of the cage and only consisted of NREM sleep. SD was followed by an immediate increase in NREM sleep time and an increase in NREM sleep EEG slow-wave activity (SWA), indicating increased sleep intensity. The cumulative increase in NREM sleep time and intensity almost made up for the NREM sleep that had been lost during 6-hr SD, but did not fully make up for the NREM sleep lost during 12-hr SD. Also, only a small fraction of the REM sleep that was lost was recovered, which mainly occurred on the second recovery night. Conclusions: The day-active tree shrew shares most of the characteristics of sleep structure and sleep homeostasis that have been reported for other mammalian species, with some peculiarities. Because the tree shrew is an established laboratory animal in neurobiological research, it may be a valuable model species for studies of sleep regulation and sleep function, with the added advantage that it is a day-active species closely related to primates. Citation: Coolen A; Hoffmann K; Barf RP; Fuchs E; Meerlo P. Telemetric study of sleep architecture and sleep homeostasis in the day-active tree shrew Tupaia belangeri. SLEEP 2012;35(6):879-888. PMID:22654207

Temporal Organization of the Sleep-Wake Cycle under Food Entrainment in the Rat

PubMed Central

Castro-Faúndez, Javiera; Díaz, Javier; Ocampo-Garcés, Adrián

2016-01-01

Study Objectives: To analyze the temporal organization of the sleep-wake cycle under food entrainment in the rat. Methods: Eighteen male Sprague-Dawley rats were chronically implanted for polysomnographic recording. During the baseline (BL) protocol, rats were recorded under a 12:12 light-dark (LD) schedule in individual isolation chambers with food and water ad libitum. Food entrainment was performed by means of a 4-h food restriction (FR) protocol starting at photic zeitgeber time 5. Eight animals underwent a 3-h phase advance of the FR protocol (A-FR). We compared the mean curves and acrophases of wakefulness, NREM sleep, and REM sleep under photic and food entrainment and after a phase advance in scheduled food delivery. We further evaluated the dynamics of REM sleep homeostasis and the NREM sleep EEG delta wave profile. Results: A prominent food-anticipatory arousal interval was observed after nine or more days of FR, characterized by increased wakefulness and suppression of REM sleep propensity and dampening of NREM sleep EEG delta activity. REM sleep exhibited a robust nocturnal phase preference under FR that was not explained by a nocturnal REM sleep rebound. The mean curve of sleep-wake states and NREM sleep EEG delta activity remained phase-locked to the timing of meals during the A-FR protocol. Conclusions: Our results support the hypothesis that under food entrainment, the sleep-wake cycle is coupled to a food-entrainable oscillator (FEO). Our findings suggest an unexpected interaction between FEO output and NREM sleep EEG delta activity generators. Citation: Castro-Faúndez J, Díaz J, Ocampo-Garcés A. Temporal organization of the sleep-wake cycle under food entrainment in the rat. SLEEP 2016;39(7):1451–1465. PMID:27091526

Increased commuting to school time reduces sleep duration in adolescents.

PubMed

Pereira, Erico Felden; Moreno, Claudia; Louzada, Fernando Mazzilli

2014-02-01

Active travel to school has been referred to as one way of increasing the level of daily physical exercise, but the actual impacts on student's general health are not clear. Recently, a possible association between active travel to school and the duration of sleep was suggested. Thus, the aim was of this study to investigate the associations between the type of transportation and travel time to school, the time in bed and sleepiness in the classroom of high school students. Information on sleeping habits and travel to school of 1126 high school students were analyzed, where 55.1% were girls with an average age of 16.24 (1.39) years old, in Santa Maria Municipality, Rio Grande do Sul, Brazil. Multiple linear regression and adjusted prevalence rates analyses were carried out. The frequency of active travel found was 61.8%. Associations between time in bed, sleepiness in the classroom and the type of transportation (active or passive) were not identified. Nevertheless, the time in bed was inversely associated with the travel time (p = 0.036) and with a phase delay. In the adjusted analysis, active travel was more incident for the students of schools in the suburbs (PR: 1.68; CI: 1.40-2.01) in comparison with the students of schools in the center. Therefore, longer trips were associated with a reduction of sleep duration of morning and night groups. Interventions concerning active travel to school must be carried out cautiously in order not to cause a reduction of the sleeping time.

Context odor presentation during sleep enhances memory in honeybees.

PubMed

Zwaka, Hanna; Bartels, Ruth; Gora, Jacob; Franck, Vivien; Culo, Ana; Götsch, Moritz; Menzel, Randolf

2015-11-02

Sleep plays an important role in stabilizing new memory traces after learning [1-3]. Here we investigate whether sleep's role in memory processing is similar in evolutionarily distant species and demonstrate that a context trigger during deep-sleep phases improves memory in invertebrates, as it does in humans. We show that in honeybees (Apis mellifera), exposure to an odor during deep sleep that has been present during learning improves memory performance the following day. Presentation of the context odor during wake phases or novel odors during sleep does not enhance memory. In humans, memory consolidation can be triggered by presentation of a context odor during slow-wave sleep that had been present during learning [3-5]. Our results reveal that deep-sleep phases in honeybees have the potential to prompt memory consolidation, just as they do in humans. This study provides strong evidence for a conserved role of sleep-and how it affects memory processes-from insects to mammals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

NASA Technical Reports Server (NTRS)

Dijk, D. J.

1999-01-01

In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

Narcolepsy susceptibility gene CCR3 modulates sleep-wake patterns in mice.

PubMed

Toyoda, Hiromi; Honda, Yoshiko; Tanaka, Susumu; Miyagawa, Taku; Honda, Makoto; Honda, Kazuki; Tokunaga, Katsushi; Kodama, Tohru

2017-01-01

Narcolepsy is caused by the loss of hypocretin (Hcrt) neurons and is associated with multiple genetic and environmental factors. Although abnormalities in immunity are suggested to be involved in the etiology of narcolepsy, no decisive mechanism has been established. We previously reported chemokine (C-C motif) receptor 3 (CCR3) as a novel susceptibility gene for narcolepsy. To understand the role of CCR3 in the development of narcolepsy, we investigated sleep-wake patterns of Ccr3 knockout (KO) mice. Ccr3 KO mice exhibited fragmented sleep patterns in the light phase, whereas the overall sleep structure in the dark phase did not differ between Ccr3 KO mice and wild-type (WT) littermates. Intraperitoneal injection of lipopolysaccharide (LPS) promoted wakefulness and suppressed both REM and NREM sleep in the light phase in both Ccr3 KO and WT mice. Conversely, LPS suppressed wakefulness and promoted NREM sleep in the dark phase in both genotypes. After LPS administration, the proportion of time spent in wakefulness was higher, and the proportion of time spent in NREM sleep was lower in Ccr3 KO compared to WT mice only in the light phase. LPS-induced changes in sleep patterns were larger in Ccr3 KO compared to WT mice. Furthermore, we quantified the number of Hcrt neurons and found that Ccr3 KO mice had fewer Hcrt neurons in the lateral hypothalamus compared to WT mice. We found abnormalities in sleep patterns in the resting phase and in the number of Hcrt neurons in Ccr3 KO mice. These observations suggest a role for CCR3 in sleep-wake regulation in narcolepsy patients.

A quasi-experimental study of the impact of school start time changes on adolescent sleep.

PubMed

Owens, Judith A; Dearth-Wesley, Tracy; Herman, Allison N; Oakes, J Michael; Whitaker, Robert C

2017-12-01

To determine whether simultaneous school start time changes (delay for some schools; advance for others) impact adolescents' sleep. Quasi-experimental study using cross-sectional surveys before and after changes to school start times in September 2015. Eight middle (grades 7-8), 3 secondary (grades 7-12), and 8 high (grades 9-12) schools in Fairfax County (Virginia) public schools. A total of 2017 (6% of ~34,900) students were surveyed before start time changes, and 1180 (3% of ~35,300) were surveyed after. A 50-minute delay (7:20 to 8:10 am) in start time for high schools and secondary schools and a 30-minute advance (8:00 to 7:30 am) for middle schools. Differences before and after start time changes in self-reported sleep duration and daytime sleepiness. Among respondents, 57.5% were non-Hispanic white, and 10.3% received free or reduced-priced school meals. Before start time changes, high/secondary and middle school students slept a mean (SD) of 7.4 (1.2) and 8.4 (1.0) hours on school nights, respectively, and had a prevalence of daytime sleepiness of 78.4% and 57.2%, respectively. Adjusted for potential confounders, students with a 50-minute delay slept 30.1 minutes longer (95% confidence interval [CI], 24.3-36.0) on school nights and had less daytime sleepiness (-4.8%; 95% CI, -8.5% to -1.1%), whereas students with a 30-minute advance slept 14.8 minutes less (95% CI, -21.6 to -8.0) and had more daytime sleepiness (8.0%; 95% CI, 2.5%-13.5%). Both advances and delays in school start times are associated with changes in adolescents' school-night sleep duration and daytime sleepiness. Larger changes might occur with later start times. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Sleep and Eating Disorders.

PubMed

Allison, Kelly C; Spaeth, Andrea; Hopkins, Christina M

2016-10-01

Insomnia is related to an increased risk of eating disorders, while eating disorders are related to more disrupted sleep. Insomnia is also linked to poorer treatment outcomes for eating disorders. However, over the last decade, studies examining sleep and eating disorders have relied on surveys, with no objective measures of sleep for anorexia nervosa or bulimia nervosa, and only actigraphy data for binge eating disorder. Sleep disturbance is better defined for night eating syndrome, where sleep efficiency is reduced and melatonin release is delayed. Studies that include objectively measured sleep and metabolic parameters combined with psychiatric comorbidity data would help identify under what circumstances eating disorders and sleep disturbance produce an additive effect for symptom severity and for whom poor sleep would increase risk for an eating disorder. Cognitive behavior therapy for insomnia may be a helpful addition to treatment of those with both eating disorder and insomnia.

Long and Short Range Correlations in Healthy and Pathologic Human Cardiac Prosses

NASA Astrophysics Data System (ADS)

Bunde, Armin

2001-03-01

Healthy sleep consists of several stages: deep sleep, light sleep and REM sleep. In this talk, recent work on the characterization of heart-rates in the three stages by long-range correlations is presented. Only in REM sleep, long-range correlations reminiscent to the wake phase occur, and the heart-rates show multifractal behaviour. In contrast, in non-REM phases, the heart-rates are uncorrelated above the typical breathing cycle time, pointing to a random regulation of the heartbeat during non-REM sleep. In deep sleep, the heart-rates show simple multifractal behaviour.

Performance Analysis of Power Saving Class of Type 1 with Both Downlink and Uplink Traffics in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Baek, Sangkyu; Choi, Bong Dae

We investigate power consumption of a mobile station with the power saving class of type 1 in the IEEE 802.16e. We deal with stochastic behavior of mobile station during not only sleep mode period but also awake mode period with both downlink and uplink traffics. Our methods for investigating the power saving class of type 1 are to construct the embedded Markov chain and the semi-Markov chain generated by the embedded Markov chain. To see the effect of the sleep mode, we obtain the average power consumption of a mobile station and the mean queueing delay of a message. Numerical results show that the larger size of the sleep window makes the power consumption of a mobile station smaller and the queueing delay of a downlink message longer.

Hemodynamic and psychological responses to laboratory stressors in women: Assessing the roles of menstrual cycle phase, premenstrual symptomatology, and sleep characteristics

PubMed Central

Lustyk, M. Kathleen B.; Douglas, Haley A.C.; Shilling, Elizabeth A.; Woods, Nancy F.

2016-01-01

This study assessed whether premenstrual symptomatology and/or sleep characteristics explain increased luteal phase psychophysiological reactivity to laboratory stressors. We hypothesized that: (1) premenstrual symptoms and sleep characteristics would explain greater luteal versus follicular phase psychophysiological reactivity, (2) symptoms and sleep characteristics would differentially predict psychophysiological reactivity within each cycle phase, and (3) symptoms and sleep characteristics would interact to affect luteal but not follicular reactivity. Freely cycling women (N=87) completed two laboratory sessions, one follicular (cycle days 5–9) and one luteal (days 7–10 post-ovulation). We employed two stressors: one physical (cold pressor task) and the other cognitive in nature (Paced Auditory Serial Addition Task). During testing, electrocardiography monitored heart rate (HR) while a timed and auto-inflatable sphygmomanometer assessed blood pressure (BP). Participants also completed a one-time self-report measure of sleep characteristics and premenstrual symptomatology as well as a measure of state anxiety pre-post stressor. Results revealed greater luteal HR and systolic BP reactivity compared to follicular reactivity (p<0.001 for both analyses), however neither premenstrual symptoms nor sleep characteristics explained this luteal increase. Within cycle analyses revealed that symptoms and sleep characteristics interacted to affect luteal phase state anxiety reactivity (R2=.32, p=.002) with negative affect being associated with more reactivity when sleep hours were low (β=.333, p=.04). Overall, significant relationships existed during the luteal phase only. Findings are discussed in terms of clinical utility and methodological challenges related to performing laboratory stress testing in women. PMID:23092740

Sleep in octogenarians during the postoperative phase after transcatheter or surgical aortic valve replacement.

PubMed

Amofah, Hege Andersen; Broström, Anders; Fridlund, Bengt; Bjorvatn, Bjørn; Haaverstad, Rune; Hufthammer, Karl Ove; Kuiper, Karel Kj; Ranhoff, Anette Hylen; Norekvål, Tone M

2016-04-01

Octogenarians with aortic stenosis are an increasing population of patients admitted for surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI). Although adequate sleep is important after illness and surgery, it has scarcely been studied in the immediate postoperative phase. To determine and compare the nature of self-reported sleep and insomnia, and recorded sleep-wake patterns in octogenarians during the in-hospital postoperative phase after SAVR or TAVI. A prospective cohort design was used that included octogenarian patients undergoing SAVR or TAVI at a regional university hospital. Self-reports were used to document sleep and insomnia, and actigraphy was used to record sleep-wake patterns. Data were collected at baseline preoperatively, and then daily for the first five postoperative days. SAVR patients experienced the most insomnia on postoperative nights later in recovery, while TAVI patients experienced the most insomnia on postoperative nights early in recovery. The median total sleep time, as measured by actigraphy, was 6.4 h, and the median sleep efficiency was 79% for the five postoperative nights, but no differences were found between SAVR and TAVI patients on this parameter. All patients slept more during daytime than at night, with SAVR patients having significantly more total sleep hours for all five days than TAVI patients (p < 0.01). Octogenarians with aortic stenosis had disturbed self-reported sleep, increased insomnia, and disturbed sleep-wake patterns postoperatively, resulting in more daytime sleep and inactivity. In patients undergoing SAVR or TAVI, sleep evolves differently during the in-hospital postoperative phase. © The European Society of Cardiology 2015.

Impact of menstrual cycle phase on endocrine effects of partial sleep restriction in healthy women.

PubMed

LeRoux, Amanda; Wright, Lisa; Perrot, Tara; Rusak, Benjamin

2014-11-01

There is extensive evidence that sleep restriction alters endocrine function in healthy young men, increasing afternoon cortisol levels and modifying levels of other hormones that regulate metabolism. Recent studies have confirmed these effects in young women, but have not investigated whether menstrual cycle phase influences these responses. The effects on cortisol levels of limiting sleep to 3h for one night were assessed in two groups of women at different points in their menstrual cycles: mid-follicular and mid-luteal. Eighteen healthy, young women, not taking oral contraceptives (age: 21.8±0.53; BMI: 22.5±0.58 [mean±SEM]), were studied. Baseline sleep durations, eating habits and menstrual cycles were monitored. Salivary samples were collected at six times of day (08:00, 08:30, 11:00, 14:00, 17:00, 20:00) during two consecutive days: first after a 10h overnight sleep opportunity (Baseline) and then after a night with a 3h sleep opportunity (Post-sleep restriction). All were awakened at the same time of day. Women in the follicular phase showed a significant decrease (p=0.004) in their cortisol awakening responses (CAR) after sleep restriction and a sustained elevation in afternoon/evening cortisol levels (p=0.008), as has been reported for men. Women in the luteal phase showed neither a depressed CAR, nor an increase in afternoon/evening cortisol levels. Secondary analyses examined the impact of sleep restriction on self-reported hunger and mood. Menstrual cycle phase dramatically altered the cortisol responses of healthy, young women to a single night of sleep restriction, implicating effects of spontaneous changes in endocrine status on adrenal responses to sleep loss. Copyright © 2014 Elsevier Ltd. All rights reserved.

BDNF in sleep, insomnia, and sleep deprivation.

PubMed

Schmitt, Karen; Holsboer-Trachsler, Edith; Eckert, Anne

2016-01-01

The protein brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of growth factors involved in plasticity of neurons in several brain regions. There are numerous evidence that BDNF expression is decreased by experiencing psychological stress and that, accordingly, a lack of neurotrophic support causes major depression. Furthermore, disruption in sleep homeostatic processes results in higher stress vulnerability and is often associated with stress-related mental disorders. Recently, we reported, for the first time, a relationship between BDNF and insomnia and sleep deprivation (SD). Using a biphasic stress model as explanation approach, we discuss here the hypothesis that chronic stress might induce a deregulation of the hypothalamic-pituitary-adrenal system. In the long-term it leads to sleep disturbance and depression as well as decreased BDNF levels, whereas acute stress like SD can be used as therapeutic intervention in some insomniac or depressed patients as compensatory process to normalize BDNF levels. Indeed, partial SD (PSD) induced a fast increase in BDNF serum levels within hours after PSD which is similar to effects seen after ketamine infusion, another fast-acting antidepressant intervention, while traditional antidepressants are characterized by a major delay until treatment response as well as delayed BDNF level increase. Key messages Brain-derived neurotrophic factor (BDNF) plays a key role in the pathophysiology of stress-related mood disorders. The interplay of stress and sleep impacts on BDNF level. Partial sleep deprivation (PSD) shows a fast action on BDNF level increase.

Do Mice Habituate to “Gentle Handling?” A Comparison of Resting Behavior, Corticosterone Levels and Synaptic Function in Handled and Undisturbed C57BL/6J Mice

PubMed Central

Longordo, Fabio; Fan, Jing; Steimer, Thierry; Kopp, Caroline; Lüthi, Anita

2011-01-01

Study Objectives: “Gentle handling” has become a method of choice for 4-6 h sleep deprivation in mice, with repeated brief handling applied before sleep deprivation to induce habituation. To verify whether mice do indeed habituate, we assess how 6 days of repeated brief handling impact on resting behavior, on stress, and on the subunit content of N-methyl-D-aspartate receptors (NMDARs) at hippocampal synapses, which is altered by sleep loss. We discuss whether repeated handling biases the outcome of subsequent sleep deprivation. Design: Adult C57BL/6J mice, maintained on a 12 h-12 h light-dark cycle, were left undisturbed for 3 days, then handled during 3 min daily for 6 days in the middle of the light phase. Mice were continuously monitored for their resting time. Serum corticosterone levels and synaptic NMDAR subunit composition were quantified. Results: Handling caused a ∼25% reduction of resting time throughout all handling days. After six, but not after one day of handling, mice had elevated serum corticosterone levels. Six-day handling augmented the presence of the NR2A subunit of NMDARs at hippocampal synapses. Conclusion: Repeated handling induces behavioral and neurochemical alterations that are absent in undisturbed animals. The persistently reduced resting time and the delayed increase in corticosterone levels indicate that mice do not habituate to handling over a 1-week period. Handling-induced modifications bias effects of gentle handling-induced sleep deprivation on sleep homeostasis, stress, glutamate receptor composition and signaling. A standardization of sleep deprivation procedures involving gentle handling will be important for unequivocally specifying how acute sleep loss affects brain function. Citation: Longordo F; Fan J; Steimer T; Kopp C; Lüthi A. Do mice habituate to “gentle handling?” A comparison of resting behavior, corticosterone levels and synaptic function in handled and undisturbed C57BL/6J mice. SLEEP 2011;34(5):679-681. PMID:21532962

Working hours associated with unintentional sleep at work among airline pilots

PubMed Central

Marqueze, Elaine Cristina; Nicola, Ana Carolina B; Diniz, Dag Hammarskjoeld M D; Fischer, Frida Marina

2017-01-01

ABSTRACT OBJECTIVE Tto identify factors associated with unintentional sleep at work of airline pilots. METHODS This is a cross-sectional epidemiological study conducted with 1,235 Brazilian airline pilots, who work national or international flights. Data collection has been performed online. We carried out a bivariate and multiple logistic regression analysis, having as dependent variable unintentional sleep at work. The independent variables were related to biodemographic data, characteristics of the work, lifestyle, and aspects of sleep. RESULTS The prevalence of unintentional sleep while flying the airplane was 57.8%. The factors associated with unintentional sleep at work were: flying for more than 65 hours a month, frequent technical delays, greater need for recovery after work, work ability below optimal, insufficient sleep, and excessive sleepiness. CONCLUSIONS The occurrence of unintentional sleep at work of airline pilots is associated with factors related to the organization of the work and health. PMID:28678902

Numerical study of entrainment of the human circadian system and recovery by light treatment.

PubMed

Kim, Soon Ho; Goh, Segun; Han, Kyungreem; Kim, Jong Won; Choi, MooYoung

2018-05-09

While the effects of light as a zeitgeber are well known, the way the effects are modulated by features of the sleep-wake system still remains to be studied in detail. A mathematical model for disturbance and recovery of the human circadian system is presented. The model combines a circadian oscillator and a sleep-wake switch that includes the effects of orexin. By means of simulations, we characterize the period-locking zone of the model, where a stable 24-hour circadian rhythm exists, and the occurrence of circadian disruption due to both insufficient light and imbalance in orexin. We also investigate how daily bright light treatments of short duration can recover the normal circadian rhythm. It is found that the system exhibits continuous phase advance/delay at lower/higher orexin levels. Bright light treatment simulations disclose two optimal time windows, corresponding to morning and evening light treatments. Among the two, the morning light treatment is found effective in a wider range of parameter values, with shorter recovery time. This approach offers a systematic way to determine the conditions under which circadian disruption occurs, and to evaluate the effects of light treatment. In particular, it could potentially offer a way to optimize light treatments for patients with circadian disruption, e.g., sleep and mood disorders, in clinical settings.

Sleep disorders, depression, anxiety and satisfaction with life among young adults: a survey of university students in Auckland, New Zealand.

PubMed

Samaranayake, Chinthaka B; Arroll, Bruce; Fernando, Antonio T

2014-08-01

Sleep symptoms, depression and anxiety often coexist and tertiary students are a population group that are increasingly recognised to be at risk. However the rates of these conditions in the New Zealand population are poorly understood. The aim of this study was to determine the rates of sleep disorders, depression and anxiety, and identify correlations between satisfactions with life among university students in Auckland. Auckland Sleep Questionnaire (ASQ) was administered to undergraduate students from six schools of The University of Auckland. The different types of sleep disorders were calculated for the students who reported a significant sleep problem lasting more than 1 month. The rate of depression, anxiety and substance use as well as the satisfaction with life scale scores were also calculated for the whole cohort. A total of 1933 students were invited to participate and 66.8% completed the questionnaire. The median age was 20 years (range 16-38) and women represented 63.9% of the total group. A total of 39.4% of the students surveyed reported having significant sleep symptoms lasting longer than 1 month. The most prevalent causes for sleep symptoms were depression and anxiety. Delayed sleep phase disorder was found in 24.9% of students and parasomnias were reported by 12.4%. Depression and anxiety were present in 17.3% and 19.7% of the total group respectively, and 7.3% of students had thoughts of "being better off dead" or self-harm. A total of 15.5% students were found to have a CAGE score greater than or equal to 2 and 9.3% reported using recreational drugs in the last 3 months. Moderate negative correlations between SWLS scores and depression and anxiety were found (r=-0.45 and r=-0.37 respectively). A large number of university students are suffering from significant sleep symptoms. Mood disorders, substance use, and circadian rhythm disorders can greatly contribute to sleep difficulties in this population group. The study also showed that harmful alcohol and drug use was common among this population group and is associated with clinically significant depression and anxiety. Accurate diagnosis using defined criteria will enable effective treatment for these conditions that impact greatly on the quality of life.

Sleep-wake cycle of an unrestrained isolated chimpanzee under entrained and free running conditions.

NASA Technical Reports Server (NTRS)

Mcnew, J. J.; Burson, R. C.; Hoshizaki, T.; Adey, W. R.

1972-01-01

Biorhythmic patterns of EEG activity - the sleep-wake cycle and the sleep cycle - were investigated in an unrestrained chimpanzee subjected to 30 days of isolation in a 4-ft cubical cage placed in a high performance sound isolation chamber. The animal received 10 days of 12 hours of light and 12 hours of dark, then 10 days of continuous light, followed by 10 more days of 12 hours of light and 12 hours of dark. The circadian sleep-wake rhythm and the wake and sleep phases of this rhythm during entrained and free running conditions were analyzed in terms of duration. The awake and nonREM sleep and REM sleep stages were also analyzed. In addition, the mean duration of the sleep cycle of the sleep phase was computed.

Michael K. Scullin: Psi Chi/APA Edwin B. Newman Graduate Research Award.

PubMed

2011-11-01

Presents Michael K. Scullin as the 2011 winner of the American Psychological Association Psi Chi/APA Edwin B. Newman Graduate Research Award. "For an outstanding research paper that examines the relationship between prospective memory in executing a goal and various lapses of time from 20 minutes up to a 12- hour wake delay and a 12-hour sleep delay. The results suggest that consolidation processes active during sleep increase the probability of goal execution. The paper, titled 'Remembering to Execute a Goal: Sleep On It!' was published in Psychological Science in 2010 and was the basis for Michael K. Scullin's selection as the recipient of the 2011 Psi Chi/APA Edwin B. Newman Graduate Research Award. Mark A. McDaniel, PhD, served as faculty research advisor." (PsycINFO Database Record (c) 2011 APA, all rights reserved). 2011 APA, all rights reserved

Sleep/wake patterns and circadian typology in preschool children based on standardized parental self-reports.

PubMed

Doi, Yuriko; Ishihara, Kaneyoshi; Uchiyama, Makoto

2014-04-01

We studied the sleep/wake patterns and circadian typology of Japanese preschool children living in the Tokyo metropolitan area (193 boys and 190 girls, 4-6 years of age) from June to July 2012 based on a standardized parental self-reporting questionnaire. Our major findings are as follows: (1) sleep/wake timing was delayed, and the duration of nocturnal sleep (sleep period as well as time in bed) increased from that on scheduled days (weekdays) to that on free days (weekends) for all ages. (2) The duration of daily sleep (24 h), including daytime nap, was longer for 4-year-old children compared with that in 5- to 6-year-old children, but not significantly different between scheduled and free days within each age group. (3) The distribution of chronotypes was 36.3% for morning (M)-type, 48.8% for neither (N)-type and 11.2% for evening (E)-type, and this distribution was independent of sex or age. (4) Sleep/wake timing delays were observed from M-type and N-type to E-type during scheduled and free days. (5) The duration of nocturnal sleep decreased but increased for 24-h sleep time from M-type and N-type to E-type on scheduled days. (6) Sleep durations did not differ among chronotypes on free days. (7) Chronotypes were associated with parents' diurnal preferences, mealtimes and attendance at kindergartens or childcare centers but not with sex, age, season of birth, exposure to multimedia or exposure to morning sunlight in their bedrooms. When these results were compared with those for older children and adolescents, similar sleep/wake patterns and circadian typology were observed, although to a lesser degree, in children as young as 4-6 years of age. Napping may compensate, in part, for an accumulated weekday sleep deficit. The distribution of chronotypes was associated with differences in sleep/wake timing and duration and was influenced by the parents' diurnal preferences and lifestyles. Further research on preschool children is required to investigate whether circadian typology affects their behavioral, emotional and cognitive development.

Toward a detailed computational model for the mammalian circadian clock

NASA Astrophysics Data System (ADS)

Leloup, Jean-Christophe; Goldbeter, Albert

2003-06-01

We present a computational model for the mammalian circadian clock based on the intertwined positive and negative regulatory loops involving the Per, Cry, Bmal1, Clock, and Rev-Erb genes. In agreement with experimental observations, the model can give rise to sustained circadian oscillations in continuous darkness, characterized by an antiphase relationship between Per/Cry/Rev-Erb and Bmal1 mRNAs. Sustained oscillations correspond to the rhythms autonomously generated by suprachiasmatic nuclei. For other parameter values, damped oscillations can also be obtained in the model. These oscillations, which transform into sustained oscillations when coupled to a periodic signal, correspond to rhythms produced by peripheral tissues. When incorporating the light-induced expression of the Per gene, the model accounts for entrainment of the oscillations by light-dark cycles. Simulations show that the phase of the oscillations can then vary by several hours with relatively minor changes in parameter values. Such a lability of the phase could account for physiological disorders related to circadian rhythms in humans, such as advanced or delayed sleep phase syndrome, whereas the lack of entrainment by light-dark cycles can be related to the non-24h sleep-wake syndrome. The model uncovers the possible existence of multiple sources of oscillatory behavior. Thus, in conditions where the indirect negative autoregulation of Per and Cry expression is inoperative, the model indicates the possibility that sustained oscillations might still arise from the negative autoregulation of Bmal1 expression.

Stroke patients' functions in personal activities of daily living in relation to sleep and socio-demographic and clinical variables in the acute phase after first-time stroke and at six months of follow-up.

PubMed

Bakken, Linda N; Kim, Hesook S; Finset, Arnstein; Lerdal, Anners

2012-07-01

To explore first-time stroke patients' degree of independence in activities of daily life in relation to sleep and other essential variables that might influence activities of daily life. Sleep has received little attention in rehabilitation of activities of daily life in stroke patients. This is a longitudinal survey and observational study design from the acute phase to six months poststroke. First-time stroke patients (n = 90) were recruited from two hospitals in eastern Norway in 2007 and 2008. Data were collected by survey interview, medical records and wrist actigraphy in the first two weeks at the hospital and at six months of follow-up. Actigraph measures patient activity and estimates sleep during the day and night. Linear regression showed that high dependence in personal activities of daily living was directly related to low estimated sleep time at night and higher estimated sleep during the day in the acute phase, controlling for socio-demographic and clinical variables. Furthermore, high estimated numbers of awakenings in the acute phase were related to lower activities of daily life functioning at six months of follow-up after controlling for socio-demographic and clinical variables. Stronger pain and a lower physical functioning showed direct relationships with lower independency level of in activities of daily life both in the acute phase and after six months. Sleep patterns in the acute phase may influence the patients' activities of daily life functioning up to six months poststroke. Furthermore, pain in the acute phase may influence the level of activities of daily life functioning in stroke patients. Nurses should pay attention to stroke patients' sleep quality and pain in the rehabilitation period after a stroke. Facilitating good sleep conditions and screening for pain should be an integral part of the rehabilitation programme. © 2012 Blackwell Publishing Ltd.

Obstructive Sleep Apnea (OSA) in Preadolescent Girls is Associated with Delayed Breast Development Compared to Girls without OSA

PubMed Central

Shaw, Natalie D.; Goodwin, James L.; Silva, Graciela E.; Hall, Janet E.; Quan, Stuart F.; Malhotra, Atul

2013-01-01

Study Objective: Adults with obstructive sleep apnea (OSA) have lower sex steroid levels than controls. We sought to determine whether OSA also interferes with reproductive hormones in adolescence by tracking the pace of pubertal development. Methods: One hundred seventy-two children in the Tucson Children's Assessment of Sleep Apnea study (TuCASA) underwent two home polysomnographic studies, spaced 4-5 years apart. Height and weight were measured at both visits, and Tanner staging of breasts/genitals and pubic hair were self-assessed by a pictorial questionnaire at follow-up. Results: Eighty-seven girls and 85 boys, age 8.9 ± 1.6 years (mean ± SD) at baseline and 13.4 ± 1.6 years at follow-up, participated. Twenty-seven percent of participants were over-weight or obese at baseline, and the majority remained so at follow-up. Twenty-six percent of girls and 28% of boys met criteria for OSA, defined as a respiratory disturbance index (RDI) ≥ 1/h associated with a 3% desaturation (RDI 3%), at baseline. There was an inverse relationship between baseline log RDI 3% and Tanner breast stage at follow-up (coefficient -1.3, p = 0.02) in girls after adjusting for age (p < 0.001), body mass index (p < 0.005), and ethnicity. Girls with OSA at baseline were more than 1 Tanner breast stage behind girls without OSA at follow-up. OSA did not affect genital development in boys or pubic hair development in either sex. Conclusions: OSA in preadolescent girls predicts delayed breast development relative to girls without OSA. Sleep fragmentation and/or hypoxia seen in OSA may interfere with reproductive development in girls. Citation: Shaw ND; Goodwin JL; Silva GE; Hall JE; Quan SF; Malhotra A. Obstructive sleep apnea (OSA) in preadolescent girls is associated with delayed breast development compared to girls without OSA. J Clin Sleep Med 2013;9(8):813-818. PMID:23946712

Improving the understanding of sleep apnea characterization using Recurrence Quantification Analysis by defining overall acceptable values for the dimensionality of the system, the delay, and the distance threshold

PubMed Central

Navarro-Mesa, Juan L.; Juliá-Serdá, Gabriel; Ramírez-Ávila, G. Marcelo; Ravelo-García, Antonio G.

2018-01-01

Our contribution focuses on the characterization of sleep apnea from a cardiac rate point of view, using Recurrence Quantification Analysis (RQA), based on a Heart Rate Variability (HRV) feature selection process. Three parameters are crucial in RQA: those related to the embedding process (dimension and delay) and the threshold distance. There are no overall accepted parameters for the study of HRV using RQA in sleep apnea. We focus on finding an overall acceptable combination, sweeping a range of values for each of them simultaneously. Together with the commonly used RQA measures, we include features related to recurrence times, and features originating in the complex network theory. To the best of our knowledge, no author has used them all for sleep apnea previously. The best performing feature subset is entered into a Linear Discriminant classifier. The best results in the “Apnea-ECG Physionet database” and the “HuGCDN2014 database” are, according to the area under the receiver operating characteristic curve, 0.93 (Accuracy: 86.33%) and 0.86 (Accuracy: 84.18%), respectively. Our system outperforms, using a relatively small set of features, previously existing studies in the context of sleep apnea. We conclude that working with dimensions around 7–8 and delays about 4–5, and using for the threshold distance the Fixed Amount of Nearest Neighbours (FAN) method with 5% of neighbours, yield the best results. Therefore, we would recommend these reference values for future work when applying RQA to the analysis of HRV in sleep apnea. We also conclude that, together with the commonly used vertical and diagonal RQA measures, there are newly used features that contribute valuable information for apnea minutes discrimination. Therefore, they are especially interesting for characterization purposes. Using two different databases supports that the conclusions reached are potentially generalizable, and are not limited by database variability. PMID:29621264

Improving the understanding of sleep apnea characterization using Recurrence Quantification Analysis by defining overall acceptable values for the dimensionality of the system, the delay, and the distance threshold.

PubMed

Martín-González, Sofía; Navarro-Mesa, Juan L; Juliá-Serdá, Gabriel; Ramírez-Ávila, G Marcelo; Ravelo-García, Antonio G

2018-01-01

Our contribution focuses on the characterization of sleep apnea from a cardiac rate point of view, using Recurrence Quantification Analysis (RQA), based on a Heart Rate Variability (HRV) feature selection process. Three parameters are crucial in RQA: those related to the embedding process (dimension and delay) and the threshold distance. There are no overall accepted parameters for the study of HRV using RQA in sleep apnea. We focus on finding an overall acceptable combination, sweeping a range of values for each of them simultaneously. Together with the commonly used RQA measures, we include features related to recurrence times, and features originating in the complex network theory. To the best of our knowledge, no author has used them all for sleep apnea previously. The best performing feature subset is entered into a Linear Discriminant classifier. The best results in the "Apnea-ECG Physionet database" and the "HuGCDN2014 database" are, according to the area under the receiver operating characteristic curve, 0.93 (Accuracy: 86.33%) and 0.86 (Accuracy: 84.18%), respectively. Our system outperforms, using a relatively small set of features, previously existing studies in the context of sleep apnea. We conclude that working with dimensions around 7-8 and delays about 4-5, and using for the threshold distance the Fixed Amount of Nearest Neighbours (FAN) method with 5% of neighbours, yield the best results. Therefore, we would recommend these reference values for future work when applying RQA to the analysis of HRV in sleep apnea. We also conclude that, together with the commonly used vertical and diagonal RQA measures, there are newly used features that contribute valuable information for apnea minutes discrimination. Therefore, they are especially interesting for characterization purposes. Using two different databases supports that the conclusions reached are potentially generalizable, and are not limited by database variability.

Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

PubMed Central

Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

2016-01-01

Within the framework of ‘Network Physiology’, we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain–heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain–heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems. PMID:27044991

Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

NASA Astrophysics Data System (ADS)

Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

2016-05-01

Within the framework of `Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems.

Bad sleep? Don't blame the moon! A population-based study.

PubMed

Haba-Rubio, José; Marques-Vidal, Pedro; Tobback, Nadia; Andries, Daniela; Preisig, Martin; Kuehner, Christine; Vollenweider, Peter; Waeber, Gérard; Luca, Gianina; Tafti, Mehdi; Heinzer, Raphaël

2015-11-01

The aim of this study was to evaluate if there is a significant effect of lunar phases on subjective and objective sleep variables in the general population. A total of 2125 individuals (51.2% women, age 58.8 ± 11.2 years) participating in a population-based cohort study underwent a complete polysomnography (PSG) at home. Subjective sleep quality was evaluated by a self-rating scale. Sleep electroencephalography (EEG) spectral analysis was performed in 759 participants without significant sleep disorders. Salivary cortisol levels were assessed at awakening, 30 min after awakening, at 11 am, and at 8 pm. Lunar phases were grouped into full moon (FM), waxing/waning moon (WM), and new moon (NM). Overall, there was no significant difference between lunar phases with regard to subjective sleep quality. We found only a nonsignificant (p = 0.08) trend toward a better sleep quality during the NM phase. Objective sleep duration was not different between phases (FM: 398 ± 3 min, WM: 402 ± 3 min, NM: 403 ± 3 min; p = 0.31). No difference was found with regard to other PSG-derived parameters, EEG spectral analysis, or in diurnal cortisol levels. When considering only subjects with apnea/hypopnea index of <15/h and periodic leg movements index of <15/h, we found a trend toward shorter total sleep time during FM (FM: 402 ± 4, WM: 407 ± 4, NM: 415 ± 4 min; p = 0.06) and shorter-stage N2 duration (FM: 178 ± 3, WM: 182 ± 3, NM: 188 ± 3 min; p = 0.05). Our large population-based study provides no evidence of a significant effect of lunar phases on human sleep. Copyright © 2015 Elsevier B.V. All rights reserved.

Estradiol and Progesterone Modulate Spontaneous Sleep Patterns and Recovery from Sleep Deprivation in Ovariectomized Rats

PubMed Central

Deurveilher, Samüel; Rusak, Benjamin; Semba, Kazue

2009-01-01

Study Objectives: Women undergo hormonal changes both naturally during their lives and as a result of sex hormone treatments. The objective of this study was to gain more knowledge about how these hormones affect sleep and responses to sleep loss. Design: Rats were ovariectomized and implanted subcutaneously with Silastic capsules containing oil vehicle, 17β-estradiol and/or progesterone. After 2 weeks, sleep/wake states were recorded during a 24-h baseline period, 6 h of total sleep deprivation induced by gentle handling during the light phase, and an 18-h recovery period. Measurements and Results: At baseline and particularly in the dark phase, ovariectomized rats treated with estradiol or estradiol plus progesterone spent more time awake at the expense of non-rapid eye movement sleep (NREMS) and/or REMS, whereas those given progesterone alone spent less time in REMS than ovariectomized rats receiving no hormones. Following sleep deprivation, all rats showed rebound increases in NREMS and REMS, but the relative increase in REMS was larger in females receiving hormones, especially high estradiol. In contrast, the normal increase in NREMS EEG delta power (an index of NREMS intensity) during recovery was attenuated by all hormone treatments. Conclusions: Estradiol promotes arousal in the active phase in sleep-satiated rats, but after sleep loss, both estradiol and progesterone selectively facilitate REMS rebound while reducing NREMS intensity. These results indicate that effects of ovarian hormones on recovery sleep differ from those on spontaneous sleep. The hormonal modulation of recovery sleep architecture may affect recovery of sleep related functions after sleep loss. Citation: Deurveilher S; Rusak B; Semba K. Estradiol and progesterone modulate spontaneous sleep patterns and recovery from sleep deprivation in ovariectomized rats. SLEEP 2009;32(7):865-877. PMID:19639749

Sleep education with self-help treatment and sleep health promotion for mental and physical wellness in Japan.

PubMed

Tanaka, Hideki; Tamura, Norihisa

The purpose of this article was to provide an overview of the effects of the sleep education with self-help treatment for student, teacher, and local resident and sleep health promotion for mental and physical wellness for elderly with actual examples of public health from the community and schools. Sleep education with self-help treatment in schools revealed that delayed or irregular sleep/wake patterns were significantly improved. Also, it was effective for improving sleep-onset latency, sleep satisfaction, mood during the morning, and daytime sleepiness. The strategy of this sleep education included the acquisition of the correct knowledge about sleep and the sleep-related behaviors that are important for improving sleep. Sleep health promotion that included short naps and exercise in the evening (Sleep health class) was effective in promoting sleep and mental health with elderly people. The interventions demonstrated that the proper awakening maintenance, keeping proper arousal level during the evening was effective in improving sleep quality. Furthermore, sleep management that included sleep education and cognitive-behavioral interventions improved sleep-related habits and the quality of sleep. In this study, a sleep educational program using minimal cognitive-behavioral modification techniques was developed. Mental and physical health was also improved with better sleep in the elderly. These results suggest that sleep health promotion is effective for mental and physical wellness for the elderly.

Effects of exercise intensity and duration on nocturnal heart rate variability and sleep quality.

PubMed

Myllymäki, Tero; Rusko, Heikki; Syväoja, Heidi; Juuti, Tanja; Kinnunen, Marja-Liisa; Kyröläinen, Heikki

2012-03-01

Acute physical exercise may affect cardiac autonomic modulation hours or even days during the recovery phase. Although sleep is an essential recovery period, the information on nocturnal autonomic modulation indicated by heart rate variability (HRV) after different exercises is mostly lacking. Therefore, this study investigated the effects of exercise intensity and duration on nocturnal HR, HRV, HR, and HRV-based relaxation, as well as on actigraphic and subjective sleep quality. Fourteen healthy male subjects (age 36 ± 4 years, maximal oxygen uptake 49 ± 4 ml/kg/min) performed five different running exercises on separate occasions starting at 6 p.m. with HR guidance at home. The effect of intensity was studied with 30 min of exercises at intensities corresponding to HR level at 45% (easy), 60% (moderate) and 75% (vigorous) of their maximal oxygen uptake. The effect of duration was studied with 30, 60, and 90 min of moderate exercises. Increased exercise intensity elevated nocturnal HR compared to control day (p < 0.001), but it did not affect nocturnal HRV. Nocturnal HR was greater after the day with 90- than 30- or 60-min exercises (p < 0.01) or control day (p < 0.001). Nocturnal HRV was lower after the 90-min exercise day compared to control day (p < 0.01). Neither exercise intensity nor duration had any impact on actigraphic or subjective sleep quality. The results suggest that increased exercise intensity and/or duration cause delayed recovery of nocturnal cardiac autonomic modulation, although long exercise duration was needed to induce changes in nocturnal HRV. Increased exercise intensity or duration does not seem to disrupt sleep quality.

Variations in Sleep and Performance by Duty Start Time in Short Haul Operations

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin

2016-01-01

Prior studies have confirmed that commercial airline pilots experience circadian phase shifts and short sleep duration following travel with layovers in different time zones. Few studies have examined the impact of early and late starts on the sleep and circadian phase of airline pilots who return to their domicile after each duty period. We recruited 44 pilots (4 female) from a short-haul commercial airline to participate in a study examining sleep and circadian phase over four duty schedules (baseline, early starts, mid-day starts, late starts). Each duty schedule was five days long, separated by three rest days. Participants completed the rosters in the same order. Sleep outcomes were estimated using wrist-borne actigraphy (Actiware Software, Respironics, Bend, OR) and daily sleep diaries. Thirteen participants volunteered to collect urine samples for the assessment of 6-sulfatoxymelatonin (aMT6s). Urine samples were collected in four-hourly bins during the day and eight-hourly bins during sleep episodes, for 24 hours immediately following each experimental duty schedule. The aMT6s results were fit to a cosine in order to obtain the acrophase to estimate circadian phase. Univariate statistics were calculated for acrophase changes, schedule start times and sleep times. All statistical analyses were computed using SAS software (Cary, IN).

Actigraphic Sleep Duration and Fragmentation in Older Women: Associations With Performance Across Cognitive Domains.

PubMed

Spira, Adam P; Stone, Katie L; Redline, Susan; Ensrud, Kristine E; Ancoli-Israel, Sonia; Cauley, Jane A; Yaffe, Kristine

2017-08-01

To determine the association of actigraphic sleep duration and fragmentation with cognition in community-dwelling older women. We studied 782 women (mean age = 87.4) of varied cognitive status from the Study of Osteoporotic Fractures who completed wrist actigraphy and the Modified Mini-Mental State Examination (3MS), California Verbal Learning Test-II-Short Form, digit span, verbal fluency tests, and the Trailmaking Test, Part B (Trails B). Total sleep time (TST) and wake after sleep onset (WASO) tertiles were our primary predictors. There were few significant associations in adjusted analyses. Compared to women with intermediate TST (mean = 430.1 minutes), those with the longest (508.7 minutes) had significantly poorer performance on the 3MS and phonemic and semantic fluency. Compared to women with the least WASO (31.5 minutes), those in the middle tertile (61.5 minutes) had significantly poorer delayed recall and those in the middle tertile and highest tertile (126.2 minutes) had poorer total recall and semantic fluency. We observed significant adjusted associations of TST with impaired 3MS performance and of WASO with impaired delayed recall, semantic fluency, and digit span. After excluding participants with adjudicated dementia diagnoses or indeterminate cognitive status, some adjusted associations remained but decreased in magnitude, others became nonsignificant, and a new association emerged. In community-dwelling older women, longer objectively measured sleep duration and greater sleep fragmentation are associated with poorer performance and impairment in only a subset of cognitive domains. Some of these associations may be driven by women with dementia in whom disturbed sleep and cognitive performance share an underlying neuropathological basis. Published by Oxford University Press on behalf of Sleep Research Society (SRS) 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Effects of chronic sleep fragmentation on wake-active neurons and the hypercapnic arousal response.

PubMed

Li, Yanpeng; Panossian, Lori A; Zhang, Jing; Zhu, Yan; Zhan, Guanxia; Chou, Yu-Ting; Fenik, Polina; Bhatnagar, Seema; Piel, David A; Beck, Sheryl G; Veasey, Sigrid

2014-01-01

Delayed hypercapnic arousals may occur in obstructive sleep apnea. The impaired arousal response is expected to promote more pronounced oxyhemoglobin desaturations. We hypothesized that long-term sleep fragmentation (SF) results in injury to or dysfunction of wake-active neurons that manifests, in part, as a delayed hypercapnic arousal response. Adult male mice were implanted for behavioral state recordings and randomly assigned to 4 weeks of either orbital platform SF (SF4wk, 30 events/h) or control conditions (Ct4wk) prior to behavioral, histological, and locus coeruleus (LC) whole cell electrophysiological evaluations. SF was successfully achieved across the 4 week study, as evidenced by a persistently increased arousal index, P < 0.01 and shortened sleep bouts, P < 0.05, while total sleep/wake times and plasma corticosterone levels were unaffected. A multiple sleep latency test performed at the onset of the dark period showed a reduced latency to sleep in SF4wk mice (P < 0.05). The hypercapnic arousal latency was increased, Ct4wk 64 ± 5 sec vs. SF4wk 154 ± 6 sec, P < 0.001, and remained elevated after a 2 week recovery (101 ± 4 sec, P < 0.001). C-fos activation in noradrenergic, orexinergic, histaminergic, and cholinergic wake-active neurons was reduced in response to hypercapnia (P < 0.05-0.001). Catecholaminergic and orexinergic projections into the cingulate cortex were also reduced in SF4wk (P < 0.01). In addition, SF4wk resulted in impaired LC neuron excitability (P < 0.01). Four weeks of sleep fragmentation (SF4wk) impairs arousal responses to hypercapnia, reduces wake neuron projections and locus coeruleus neuronal excitability, supporting the concepts that some effects of sleep fragmentation may contribute to impaired arousal responses in sleep apnea, which may not reverse immediately with therapy.

Interaction of sleep and emotional content on the production of false memories.

PubMed

McKeon, Shannon; Pace-Schott, Edward F; Spencer, Rebecca M C

2012-01-01

Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep's effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list's "gist." Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details.

Female impulsive aggression: a sleep research perspective.

PubMed

Lindberg, Nina; Tani, Pekka; Putkonen, Hanna; Sailas, Eila; Takala, Pirjo; Eronen, Markku; Virkkunen, Matti

2009-01-01

The rate of violent crimes among girls and women appears to be increasing. One in every five female prisoners has been reported to have antisocial personality disorder. However, it has been quite unclear whether the impulsive, aggressive behaviour among women is affected by the same biological mechanisms as among men. Psychiatric sleep research has attempted to identify diagnostically sensitive and specific sleep patterns associated with particular disorders. Most psychiatric disorders are typically characterized by a severe sleep disturbance associated with decreased amounts of slow wave sleep (SWS), the physiologically significant, refreshing part of sleep. Among men with antisocial behaviour with severe aggression, on the contrary, increased SWS has been reported, reflecting either specific brain pathology or a delay in the normal development of human sleep patterns. In our preliminary study among medication-free, detoxified female homicidal offenders with antisocial personality disorder, the same profound abnormality in sleep architecture was found. From the perspective of sleep research, the biological correlates of severe impulsive aggression seem to share similar features in both sexes.

Effect of oxcarbazepine on sleep architecture.

PubMed

Ayala-Guerrero, Fructuoso; Mexicano, Graciela; González, Valentín; Hernandez, Mario

2009-07-01

The most common side effects following administration of antiepileptic drugs involve alterations in sleep architecture and varying degrees of daytime sleepiness. Oxcarbazepine is a drug that is approved as monotherapy for the treatment of partial seizures and generalized tonic-clonic seizures. However, there is no information about its effects on sleep pattern organization; therefore, the objective of this work was to analyze such effects. Animals (Wistar rats) exhibited three different behavioral and electrophysiological states of vigilance: wakefulness, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Oral treatment with oxcarbazepine (100 mg/kg) produced an increment in total sleep time throughout the recording period. This increment involved both SWS and REM sleep. Mean duration of the REM sleep phase was not affected. In contrast, the frequency of this sleep phase increased significantly across the 10-hour period. REM sleep latency shortened significantly. Results obtained in this work indicate that oxcarbazepine's acute effects point to hypnotic properties.

Effect of bright light on EEG activities and subjective sleepiness to mental task during nocturnal sleep deprivation.

PubMed

Yokoi, Mari; Aoki, Ken; Shimomura, Yoshihiro; Iwanaga, Koichi; Katsuura, Tetsuo; Shiomura, Yoshihiro

2003-11-01

The purpose of this study was to investigate the effect of the exposure to bright light on EEG activity and subjective sleepiness at rest and at the mental task during nocturnal sleep deprivation. Eight male subjects lay awake in semi-supine in a reclining seat from 21:00 to 04:30 under the bright (BL; >2500 lux) or the dim (DL; <150 lux) light conditions. During the sleep deprivation, the mental task (Stroop color-word conflict test: CWT) was performed each 15 min in one hour. EEG, subjective sleepiness, rectal and mean skin temperatures and urinary melatonin concentrations were measured. The subjective sleepiness increased with time of sleep deprivation during both rest and CWT under the DL condition. The exposure to bright light delayed for 2 hours the increase in subjective sleepiness at rest and suppressed the increase in that during CWT. The bright light exposure also delayed the increase in the theta and alpha wave activities in EEG at rest. In contrast, the effect of the bright light exposure on the theta and alpha wave activities disappeared by CWT. Additionally, under the BL condition, the entire theta activity during CWT throughout nocturnal sleep deprivation increased significantly from that in a rest condition. Our results suggest that the exposure to bright light throughout nocturnal sleep deprivation influences the subjective sleepiness during the mental task and the EEG activity, as well as the subjective sleepiness at rest. However, the effect of the bright light exposure on the EEG activity at the mental task diminishes throughout nocturnal sleep deprivation.

Discriminating neurological from psychiatric hypersomnia using the forced awakening test.

PubMed

Peter-Derex, L; Perrin, F; Petitjean, T; Garcia-Larrea, L; Bastuji, H

2013-06-01

Sleep inertia refers to the inability to attain full alertness following awakening from sleep and is a major component of hypersomnia. As event-related potentials (ERPs) are correlated to the degree of consciousness, they allow exploring information processing in transitional states of vigilance. Their modifications during forced awakening (FA) context have been shown to reflect sleep inertia. To assess the diagnostic value of a FA test using an oddball stimulation protocol during a nap in a representative sample of patients with excessive daytime sleepiness (EDS). One hundred and seventy three patients [30 narcolepsy, 62 idiopathic hypersomnia, 33 sleep apnoea syndrome, and 48 other (mainly psychiatric) hypersomnia] performed an auditory target detection stimulation task during pre-, post-nap wakefulness, and during two successive intra-nap FA while the EEG was simultaneously recorded. Both the accuracy of target detection and the ERPs were evaluated. ERPs during forced awakening test were considered to reflect sleep inertia if they presented with a P300 delay and/or sleep negativities (N350/N550). Pre-nap behavior and ERPs were normal in all patients. Behavioral results were significantly worse during FA than during wakefulness for all groups of patients. P300 latencies were significantly delayed on FA conditions in each group of patients except the psychiatric group. Sensitivity and specificity for detection of sleep inertia were 64% and 94%, respectively, with predictive values of 96% (positive) and 50% (negative). Our results suggest that the FA test could be helpful as a diagnostic procedure for discriminating neurological from psychiatric hypersomnia. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Skin Temperature Rhythms in Humans Respond to Changes in the Timing of Sleep and Light.

PubMed

Cuesta, Marc; Boudreau, Philippe; Cermakian, Nicolas; Boivin, Diane B

2017-06-01

Body temperature is known to vary with circadian phase and to be influenced by factors that can mask its circadian expression. We wanted to test whether skin temperature rhythms were sensitive to an abrupt shift of the sleep schedule and to the resetting effects of light. Nineteen healthy subjects spent 6 days in time isolation and underwent a simulated night-shift procedure. They were assigned to either a control group ( n = 10) or bright light group ( n = 9) and measurements were taken under a baseline day-oriented schedule and during the 4 th cycle of a night-oriented schedule. In the bright light group, participants were exposed to a 3-cycle 8-h exposure of ~6,500 lux at night, while the control group remained in dim light conditions (~3 lux). Skin temperature was recorded in 10 and 4 participants from the control and bright light groups, respectively. We found significant circadian rhythms of plasma melatonin, core body temperature (CBT), and skin temperature at baseline for both groups ( p < 0.001 for all). Rhythms of melatonin, CBT, and skin temperature following night shifts were significantly phase delayed by about 7 to 9 h ( p < 0.05) in response to bright light at night, whereas there was no shift in the control group. In addition, we found that at bedtime melatonin does not consistently increase before the increase in distal skin temperature and subsequent decrease in CBT, in contrast to what has been previously reported. The present study shows that, in constant posture conditions, skin temperature rhythms have an evoked component sensitive to abrupt changes in the timing of sleep. They also comprise an endogenous component that is sensitive to the resetting effects of bright light exposure. These results have applications for the determination of circadian phase, as skin temperature is less intrusive than rectal temperature recordings.

Phase-Locked Loop for Precisely Timed Acoustic Stimulation during Sleep

PubMed Central

Santostasi, Giovanni; Malkani, Roneil; Riedner, Brady; Bellesi, Michele; Tononi, Giulio; Paller, Ken A.; Zee, Phyllis C.

2016-01-01

Background A Brain-Computer Interface could potentially enhance the various benefits of sleep. New Method We describe a strategy for enhancing slow-wave sleep (SWS) by stimulating the sleeping brain with periodic acoustic stimuli that produce resonance in the form of enhanced slow-wave activity in the electroencephalogram (EEG). The system delivers each acoustic stimulus at a particular phase of an electrophysiological rhythm using a Phase-Locked Loop (PLL). Results The PLL is computationally economical and well suited to follow and predict the temporal behavior of the EEG during slow-wave sleep. Comparison with Existing Methods Acoustic stimulation methods may be able to enhance SWS without the risks inherent in electrical stimulation or pharmacological methods. The PLL method differs from other acoustic stimulation methods that are based on detecting a single slow wave rather than modeling slow-wave activity over an extended period of time. Conclusions By providing real-time estimates of the phase of ongoing EEG oscillations, the PLL can rapidly adjust to physiological changes, thus opening up new possibilities to study brain dynamics during sleep. Future application of these methods hold promise for enhancing sleep quality and associated daytime behavior and improving physiologic function. PMID:26617321

Sleep Pattern of Adolescents in a School in Delhi, India: Impact on their Mood and Academic Performance.

PubMed

Singh, Ruchi; Suri, Jagdish C; Sharma, Renuka; Suri, Tejas; Adhikari, Tulsi

2018-03-16

To examine the sleep pattern and observe differences in sleep routines, phase preferences, mood, attendance, and academic performance among different adolescent age students. Secondly, to observe the age at which sleep phase transition and changes in sleep requirement become evident. A cross-sectional study was conducted among 501 students (aged 11-15 y) of a school in Delhi, India. Students were evaluated for their sleep patterns, sleep duration, habits of napping, quality of sleep, sleepiness, depression, phase preferences by self-reported school sleep habits survey questionnaire along with school performance and attendance. Significant differences were found in sleep pattern of students aged 11-12 y and 13-15 y. Bedtime shifted to a later time with increasing age but early morning schools kept the wake time same, leading to a decline in total sleep duration of older adolescents. Older adolescents had higher depression but poor attendance and academic performance. Prevalence of sleep deprivation increased with age, from 83.7% to 87.1% in 11-12 y to 90.5% to 92.5% in 13-15 y. The study clearly identifies 12-13 y as age of transition of sleep pattern among adolescents. Though significant differences were found in the academic performance, mood and attendance among preteens and teens but no direct association was seen between academic performances and sleep pattern. A complex multifactorial association between sleep patterns, attendance, mood and academic performance which may change over days, months, or years should be explored further in a longitudinal follow up study.

Effects of Chronic Sleep Fragmentation on Wake-Active Neurons and the Hypercapnic Arousal Response

PubMed Central

Li, Yanpeng; Panossian, Lori A.; Zhang, Jing; Zhu, Yan; Zhan, Guanxia; Chou, Yu-Ting; Fenik, Polina; Bhatnagar, Seema; Piel, David A.; Beck, Sheryl G.; Veasey, Sigrid

2014-01-01

Study Objectives: Delayed hypercapnic arousals may occur in obstructive sleep apnea. The impaired arousal response is expected to promote more pronounced oxyhemoglobin desaturations. We hypothesized that long-term sleep fragmentation (SF) results in injury to or dysfunction of wake-active neurons that manifests, in part, as a delayed hypercapnic arousal response. Design: Adult male mice were implanted for behavioral state recordings and randomly assigned to 4 weeks of either orbital platform SF (SF4wk, 30 events/h) or control conditions (Ct4wk) prior to behavioral, histological, and locus coeruleus (LC) whole cell electrophysiological evaluations. Measurements and Results: SF was successfully achieved across the 4 week study, as evidenced by a persistently increased arousal index, P < 0.01 and shortened sleep bouts, P < 0.05, while total sleep/wake times and plasma corticosterone levels were unaffected. A multiple sleep latency test performed at the onset of the dark period showed a reduced latency to sleep in SF4wk mice (P < 0.05). The hypercapnic arousal latency was increased, Ct4wk 64 ± 5 sec vs. SF4wk 154 ± 6 sec, P < 0.001, and remained elevated after a 2 week recovery (101 ± 4 sec, P < 0.001). C-fos activation in noradrenergic, orexinergic, histaminergic, and cholinergic wake-active neurons was reduced in response to hypercapnia (P < 0.05-0.001). Catecholaminergic and orexinergic projections into the cingulate cortex were also reduced in SF4wk (P < 0.01). In addition, SF4wk resulted in impaired LC neuron excitability (P < 0.01). Conclusions: Four weeks of sleep fragmentation (SF4wk) impairs arousal responses to hypercapnia, reduces wake neuron projections and locus coeruleus neuronal excitability, supporting the concepts that some effects of sleep fragmentation may contribute to impaired arousal responses in sleep apnea, which may not reverse immediately with therapy. Citation: Li Y; Panossian LA; Zhang J; Zhu Y; Zhan G; Chou YT; Fenik P; Bhatnagar S; Piel DA; Beck SG; Veasey S. Effects of chronic sleep fragmentation on wake-active neurons and the hypercapnic arousal response. SLEEP 2014;37(1):51-64. PMID:24470695

Characteristics associated with Sleep Duration, Chronotype, and Social jet lag in Adolescents

PubMed Central

Malone, Susan Kohl; Zemel, Babette S.; Compher, Charlene; Souders, Margaret; Chittams, Jesse; Thompson, Aleda Leis; Lipman, Terri H.

2015-01-01

Sleep is a complex behavior with numerous health implications. Identifying socio-demographic and behavioral characteristics of sleep are important for determining those at greatest risk for sleep-related health disparities. In this cross-sectional study, general linear models were used to examine socio-demographic and behavioral characteristics associated with sleep duration, chronotype, and social jet lag in adolescents. One hundred fifteen participants completed Phase I (self-reported sleep measures); 69 of these participants completed Phase II (actigraphy-estimated sleep measures). Black adolescents had shorter free night sleep than Hispanics. Youth with later chronotypes ate fewer fruits and vegetables, drank more soda, were less physically active, and took more daytime naps. Based on these findings, recommendations for individual support and school policies are provided. PMID:26376832

[Hygiene in Sleep: Problems of Sleeping Habits in Shift Workers].

PubMed

Takada, Masumi

2018-01-01

Since World War II, Japan has achieved remarkable economic development and has become an advanced country. Particularly in the industrial field, a production system has been developed to reduce the loss of machining time by adopting a shiftwork in factories operating 24 hours a day, which contributes to the improvement of productivity. Nowadays, this shiftwork practice has spread from the industrial field to other businesses such as 24-hour entertainment facilities and convenience stores, which lead to sleep deprivation in Japanese society. Even at home, certain conditions adversely affect sleeping habits. We are concerned about the risks of physical and mental health, impairments posed by the use of tablets, PCs, smartphones, and other devices so popular in today's Japan, as they delay sleep. It is urgent to improve poor sleeping habits because their outcomes such as sleep disorders and deprivation may also lead to traffic and industrial accidents.

Prevalence and factors associated with poor sleep quality among secondary school teachers in a developing country.

PubMed

Musa, Nor Asma; Moy, Foong Ming; Wong, Li Ping

2018-05-31

This study aimed to determine the prevalence and factors associated with poor sleep quality among secondary school teachers in the state of Selangor, Malaysia. This was a cross sectional study, conducted in two phases. Phase I tested the reliability of the Pittsburgh Sleep Quality Index in the Malay language (M-PSQI), whereas Phase II determined the prevalence and factors associated with poor sleep quality where a total of 1871 secondary school teachers were studied. Participants were recruited using multistage sampling. Self-administered questionnaire was used to collect data on socio-demographic and teaching characteristics, comorbidities and characteristics of sleep. The M-PSQI was used to measure sleep quality. The Depression Anxiety Stress Scale-21 was used to measure mental health status. Results showed that the M-PSQI had a good internal consistency and moderate reliability. The prevalence of poor sleep quality was 61 (95% CI: 54-67) %. Total teaching hours/day, depression and stress were significantly associated with poor sleep quality in the univariate analysis, while only stress (OR 1.04; 95% CI 1.02-1.05%) remained significant in the multivariate analyses. In conclusion, stress level of the secondary school teachers should be reduced to improve sleep quality.

A global quantification of "normal" sleep schedules using smartphone data.

PubMed

Walch, Olivia J; Cochran, Amy; Forger, Daniel B

2016-05-01

The influence of the circadian clock on sleep scheduling has been studied extensively in the laboratory; however, the effects of society on sleep remain largely unquantified. We show how a smartphone app that we have developed, ENTRAIN, accurately collects data on sleep habits around the world. Through mathematical modeling and statistics, we find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep. A country's average bedtime, but not average wake time, predicts sleep duration. We further show that mathematical models based on controlled laboratory experiments predict qualitative trends in sunrise, sunset, and light level; however, these effects are attenuated in the real world around bedtime. Additionally, we find that women schedule more sleep than men and that users reporting that they are typically exposed to outdoor light go to sleep earlier and sleep more than those reporting indoor light. Finally, we find that age is the primary determinant of sleep timing, and that age plays an important role in the variability of population-level sleep habits. This work better defines and personalizes "normal" sleep, produces hypotheses for future testing in the laboratory, and suggests important ways to counteract the global sleep crisis.

General anesthesia alters time perception by phase shifting the circadian clock.

PubMed

Cheeseman, James F; Winnebeck, Eva C; Millar, Craig D; Kirkland, Lisa S; Sleigh, James; Goodwin, Mark; Pawley, Matt D M; Bloch, Guy; Lehmann, Konstantin; Menzel, Randolf; Warman, Guy R

2012-05-01

Following general anesthesia, people are often confused about the time of day and experience sleep disruption and fatigue. It has been hypothesized that these symptoms may be caused by general anesthesia affecting the circadian clock. The circadian clock is fundamental to our well-being because it regulates almost all aspects of our daily biochemistry, physiology, and behavior. Here, we investigated the effects of the most common general anesthetic, isoflurane, on time perception and the circadian clock using the honeybee (Apis mellifera) as a model. A 6-h daytime anesthetic systematically altered the time-compensated sun compass orientation of the bees, with a mean anticlockwise shift in vanishing bearing of 87° in the Southern Hemisphere and a clockwise shift in flight direction of 58° in the Northern Hemisphere. Using the same 6-h anesthetic treatment, time-trained bees showed a delay in the start of foraging of 3.3 h, and whole-hive locomotor-activity rhythms were delayed by an average of 4.3 h. We show that these effects are all attributable to a phase delay in the core molecular clockwork. mRNA oscillations of the central clock genes cryptochrome-m and period were delayed by 4.9 and 4.3 h, respectively. However, this effect is dependent on the time of day of administration, as is common for clock effects, and nighttime anesthesia did not shift the clock. Taken together, our results suggest that general anesthesia during the day causes a persistent and marked shift of the clock effectively inducing "jet lag" and causing impaired time perception. Managing this effect in humans is likely to help expedite postoperative recovery.

Changes in Body Water Caused by Sleep Deprivation in Taeeum and Soyang Types in Sasang Medicine: Prospective Intervention Study

PubMed Central

2017-01-01

Background There is a negative relationship between sleep deprivation and health. However, no study has investigated the effect of sleep deprivation on individuals with different body composition. The aim of this study was to determine the differential effect of sleep deprivation in individuals with different body compositions (fluid) according to Soyang type (SY) and Taeeum type (TE). Methods Sixty-two cognitively normal, middle-aged people with normal sleep patterns were recruited from the local population. The duration of participants' sleep was restricted to 4 h/day during the intervention phase. To examine the physiological changes brought on by sleep deprivation and recovery, 10 ml of venous blood was obtained. Results Total Body Water (TBW) and Extracellular Water (ECW) were significantly different between the groups in the intervention phase. Physiological parameters also varied from the beginning of the resting phase to the end of the experiment. Potassium levels changed more in SY than TE individuals. Conclusion Participants responded differently to the same amount of sleep deprivation depending on their Sasang constitution types. This study indicated that SY individuals were more sensitive to sleep deprivation and were slower to recover from the effects of sleep deprivation than TE individuals. PMID:28676829

Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep.

PubMed

Röösli, Martin; Jüni, Peter; Braun-Fahrländer, Charlotte; Brinkhof, Martin W G; Low, Nicola; Egger, Matthias

2006-06-01

Popular belief holds that the lunar cycle affects human physiology, behaviour and health. We examined the influence of moon phase on sleep duration in a secondary analysis of a feasibility study of mobile telephone base stations and sleep quality. We studied 31 volunteers (18 women and 13 men, mean age 50 years) from a suburban area of Switzerland longitudinally over 6 weeks, including two full moons. Subjective sleep duration was calculated from sleep diary data. Data were analysed using multiple linear regression models with random effects. Mean sleep duration was 6 h 49 min. Subjective sleep duration varied with the lunar cycle, from 6 h 41 min at full moon to 7 h 00 min at new moon (P < 0.001). Average sleep duration was shortened by 68 min during the week compared with weekends (P < 0.001). Men slept 17 min longer than women (P < 0.001) and sleep duration decreased with age (P < 0.001). There was also evidence that rating of fatigue in the morning was associated with moon phase, with more tiredness (P = 0.027) at full moon. The study was designed for other purposes and the association between lunar cycle and sleep duration will need to be confirmed in further studies.

A Randomized, Double-Blind, Single-Dose, Placebo-Controlled, Multicenter, Polysomnographic Study of Gabapentin in Transient Insomnia Induced by Sleep Phase Advance

PubMed Central

Rosenberg, Russell P.; Hull, Steven G.; Lankford, D. Alan; Mayleben, David W.; Seiden, David J.; Furey, Sandy A.; Jayawardena, Shyamalie; Roth, Thomas

2014-01-01

Study Objectives: To evaluate the effects of single doses of gabapentin 250 and 500 mg on polysomnographic (PSG) and participant-reported sleep measures in a 5-h phase advance insomnia model. Methods: Adults reporting occasional disturbed sleep received gabapentin 500 mg (n = 125), 250 mg (n = 125), or placebo (n = 127) 30 min prior to bedtime and were in bed from 17:00 to 01:00, ∼5 h before their habitual bedtime. Sleep was assessed by PSG, post-sleep questionnaire, and the Karolinska Sleep Diary (KSD). Next-day residual effects (Digit Symbol Substitution Test [DSST] and Stanford Sleepiness Scale [SSS]) and tolerability were assessed. Results: Demographics were comparable among groups. Among PSG endpoints, wake after sleep onset (primary endpoint) (135.7 [placebo], 100.7 [250 mg], and 73.2 [500 mg] min) was significantly lower and total sleep time (TST) (311.4, 356.5, and 378.7 min) significantly greater in both gabapentin groups versus placebo. Latency to persistent sleep was not significantly different among groups. Percent slow wave sleep (12.6%, 15.4%, and 17.0%, respectively) was significantly greater and percent stage 1 (15.1%, 11.8%, and 10.8%, respectively) significantly lower relative to placebo. Gabapentin was associated with significantly higher values of KSD Sleep Quality Index and reported TST versus placebo; no other reported outcomes were significant. Neither gabapentin dose produced evidence of next-day residual effects as measured by DSST and SSS. Adverse events were infrequent (< 5%). Conclusion: Participants with occasional disturbed sleep treated with gabapentin showed significantly longer sleep duration and greater depth (versus placebo) in response to a phase advance manipulation known to disrupt sleep maintenance. Citation: Rosenberg RP, Hull SG, Lankford DA, Mayleben DW, Seiden DJ, Furey SA, Jayawardena S, Roth T. A randomized, double-blind, single-dose, placebo-controlled, multicenter, polysomnographic study of gabapentin in transient insomnia induced by sleep phase advance. J Clin Sleep Med 2014;10(10):1093-1100. PMID:25317090

Sleep in octogenarians during the postoperative phase after transcatheter or surgical aortic valve replacement

PubMed Central

Amofah, Hege Andersen; Broström, Anders; Fridlund, Bengt; Bjorvatn, Bjørn; Haaverstad, Rune; Hufthammer, Karl Ove; Kuiper, Karel KJ; Ranhoff, Anette Hylen; Norekvål, Tone M

2015-01-01

Background: Octogenarians with aortic stenosis are an increasing population of patients admitted for surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI). Although adequate sleep is important after illness and surgery, it has scarcely been studied in the immediate postoperative phase. Aims: To determine and compare the nature of self-reported sleep and insomnia, and recorded sleep–wake patterns in octogenarians during the in-hospital postoperative phase after SAVR or TAVI. Methods: A prospective cohort design was used that included octogenarian patients undergoing SAVR or TAVI at a regional university hospital. Self-reports were used to document sleep and insomnia, and actigraphy was used to record sleep–wake patterns. Data were collected at baseline preoperatively, and then daily for the first five postoperative days. Results: SAVR patients experienced the most insomnia on postoperative nights later in recovery, while TAVI patients experienced the most insomnia on postoperative nights early in recovery. The median total sleep time, as measured by actigraphy, was 6.4 h, and the median sleep efficiency was 79% for the five postoperative nights, but no differences were found between SAVR and TAVI patients on this parameter. All patients slept more during daytime than at night, with SAVR patients having significantly more total sleep hours for all five days than TAVI patients (p < 0.01). Conclusion: Octogenarians with aortic stenosis had disturbed self-reported sleep, increased insomnia, and disturbed sleep–wake patterns postoperatively, resulting in more daytime sleep and inactivity. In patients undergoing SAVR or TAVI, sleep evolves differently during the in-hospital postoperative phase. PMID:26635329

Experimental sleep restriction causes endothelial dysfunction in healthy humans.

PubMed

Calvin, Andrew D; Covassin, Naima; Kremers, Walter K; Adachi, Taro; Macedo, Paula; Albuquerque, Felipe N; Bukartyk, Jan; Davison, Diane E; Levine, James A; Singh, Prachi; Wang, Shihan; Somers, Virend K

2014-11-25

Epidemiologic evidence suggests a link between short sleep duration and cardiovascular risk, although the nature of any relationship and mechanisms remain unclear. Short sleep duration has also been linked to an increase in cardiovascular events. Endothelial dysfunction has itself been implicated as a mediator of heightened cardiovascular risk. We sought to determine the effect of 8 days/8 nights of partial sleep restriction on endothelial function in healthy humans. Sixteen healthy volunteers underwent a randomized study of usual sleep versus sleep restriction of two-thirds normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcome was endothelial function measured by flow-mediated brachial artery vasodilatation (FMD). Those randomized to sleep restriction slept 5.1 hours/night during the experimental period compared with 6.9 hours/night in the control group. Sleep restriction was associated with significant impairment in FMD (8.6±4.6% during the initial pre-randomization acclimation phase versus 5.2±3.4% during the randomized experimental phase, P=0.01) whereas no change was seen in the control group (5.0±3.0 during the acclimation phase versus 6.73±2.9% during the experimental phase, P=0.10) for a between-groups difference of -4.40% (95% CI -7.00 to -1.81%, P=0.003). No change was seen in non-flow mediated vasodilatation (NFMD) in either group. In healthy individuals, moderate sleep restriction causes endothelial dysfunction. ClinicalTrials.gov. Unique identifier: NCT01334788. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Sleep Enhances Recognition Memory for Conspecifics as Bound into Spatial Context

PubMed Central

Sawangjit, Anuck; Kelemen, Eduard; Born, Jan; Inostroza, Marion

2017-01-01

Social memory refers to the fundamental ability of social species to recognize their conspecifics in quite different contexts. Sleep has been shown to benefit consolidation, especially of hippocampus-dependent episodic memory whereas effects of sleep on social memory are less well studied. Here, we examined the effect of sleep on memory for conspecifics in rats. To discriminate interactions between the consolidation of social memory and of spatial context during sleep, adult Long Evans rats performed on a social discrimination task in a radial arm maze. The Learning phase comprised three 10-min sampling sessions in which the rats explored a juvenile rat presented at a different arm of the maze in each session. Then the rats were allowed to sleep (n = 18) or stayed awake (n = 18) for 120 min. During the following 10-min Test phase, the familiar juvenile rat (of the Learning phase) was presented along with a novel juvenile rat, each rat at an opposite arm of the maze. Significant social recognition memory, as indicated by preferential exploration of the novel over the familiar conspecific, occurred only after post-learning sleep, but not after wakefulness. Sleep, compared with wakefulness, significantly enhanced social recognition during the first minute of the Test phase. However, memory expression depended on the spatial configuration: Significant social recognition memory emerged only after sleep when the rat encountered the novel conspecific at a place different from that of the familiar juvenile in the last sampling session before sleep. Though unspecific retrieval-related effects cannot entirely be excluded, our findings suggest that sleep, rather than independently enhancing social and spatial aspects of memory, consolidates social memory by acting on an episodic representation that binds the memory of the conspecific together with the spatial context in which it was recently encountered. PMID:28270755

A Biphasic Change of Regional Blood Volume in the Frontal Cortex during Non-Rapid Eye Movement Sleep: A Near-Infrared Spectroscopy Study.

PubMed

Zhang, Zhongxing; Khatami, Ramin

2015-08-01

Current knowledge on hemodynamics in sleep is limited because available techniques do not allow continuous recordings and mainly focus on cerebral blood flow while neglecting other important parameters, such as blood volume (BV) and vasomotor activity. Observational study. Continuous measures of hemodynamics over the left forehead and biceps were performed using near-infrared spectroscopy (NIRS) during nocturnal polysomnography in 16 healthy participants in sleep laboratory. Temporal dynamics and mean values of cerebral and muscular oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), and BV during different sleep stages were compared. A biphasic change of cerebral BV was observed which contrasted a monotonic increase of muscular BV during non-rapid eye movement sleep. A significant decrement in cerebral HbO2 and BV accompanied by an increase of HHb was recorded at sleep onset (Phase I). Prior to slow wave sleep (SWS) HbO2 and BV turned to increase whereas HHb began to decrease in subsequent Phase II suggested increased brain perfusion during SWS. The cerebral HbO2 slope correlated to BV slope in Phase I and II, but it only correlated to HHb slope in Phase II. The occurrence time of inflection points correlated to SWS latencies. Initial decrease of brain perfusion with decreased blood volume (BV) and oxygenated hemoglobin (HbO2) together with increasing muscular BV fit thermoregulation process at sleep onset. The uncorrelated and correlated slopes of HbO2 and deoxygenated hemoglobin indicate different mechanisms underlying the biphasic hemodynamic process in light sleep and slow wave sleep (SWS). In SWS, changes in vasomotor activity (i.e., increased vasodilatation) may mediate increasing cerebral and muscular BV. © 2015 Associated Professional Sleep Societies, LLC.

A cross-syndrome study of the differential effects of sleep on declarative memory consolidation in children with neurodevelopmental disorders.

PubMed

Ashworth, Anna; Hill, Catherine M; Karmiloff-Smith, Annette; Dimitriou, Dagmara

2017-03-01

Sleep plays an active role in memory consolidation. Because children with Down syndrome (DS) and Williams syndrome (WS) experience significant problems with sleep and also with learning, we predicted that sleep-dependent memory consolidation would be impaired in these children when compared to typically developing (TD) children. This is the first study to provide a cross-syndrome comparison of sleep-dependent learning in school-aged children. Children with DS (n = 20) and WS (n = 22) and TD children (n = 33) were trained on the novel Animal Names task where they were taught pseudo-words as the personal names of ten farm and domestic animals, e.g. Basco the cat, with the aid of animal picture flashcards. They were retested following counterbalanced retention intervals of wake and sleep. Overall, TD children remembered significantly more words than both the DS and WS groups. In addition, their performance improved following night-time sleep, whereas performance over the wake retention interval remained stable, indicating an active role of sleep for memory consolidation. Task performance of children with DS did not significantly change following wake or sleep periods. However, children with DS who were initially trained in the morning continued to improve on the task at the following retests, so that performance on the final test was greater for children who had initially trained in the morning than those who trained in the evening. Children with WS improved on the task between training and the first retest, regardless of whether sleep or wake occurred during the retention interval. This suggests time-dependent rather than sleep-dependent learning in children with WS, or tiredness at the end of the first session and better performance once refreshed at the start of the second session, irrespective of the time of day. Contrary to expectations, sleep-dependent learning was not related to baseline level of performance. The findings have significant implications for educational strategies, and suggest that children with DS should be taught more important or difficult information in the morning when they are better able to learn, whilst children with WS should be allowed a time delay between learning phases to allow for time-dependent memory consolidation, and frequent breaks from learning so that they are refreshed and able to perform at their best. © 2015 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

Sleep behaviors in traditional-age college students: A state of the science review with implications for practice.

PubMed

Owens, Heather; Christian, Becky; Polivka, Barbara

2017-11-01

The purpose of this systematic review was to examine influences affecting sleep behavior in traditional-age college students and to advocate for improved sleep behavior assessments. A literature search of CINAHL, MEDLINE, and PubMed databases was performed using the search terms "college students" and "sleep" in the title that were published in English from 1978 to 2016. The circadian clock is reset in traditional-age college students leading to delayed sleep times. Newly realized autonomy and increased use of technology also prevent traditional-age college students from obtaining sufficient sleep. Insufficient sleep experienced by these students has been linked to insulin resistance, hypertension, diabetes, weight gain, and stress. Sleep insufficiency increases the risk for pedestrian, motor vehicle, and domestic and occupational injuries. Insufficient sleep may result in poor academic performance influencing subsequent health outcomes. Evidence supports the need for nurse practitioners and other healthcare providers to incorporate systematic sleep behavior assessments to improve health outcomes among traditional-age college students. ©2017 American Association of Nurse Practitioners.

The Pittsburgh Sleep Diary

NASA Technical Reports Server (NTRS)

Monk, T. H.; Reynolds CF, 3. d.; Kupfer, D. J.; Buysse, D. J.; Coble, P. A.; Hayes, A. J.; Machen, M. A.; Petrie, S. R.; Ritenour, A. M.

1994-01-01

Increasingly, there is a need in both research and clinical practice to document and quantify sleep and waking behaviors in a comprehensive manner. The Pittsburgh Sleep Diary (PghSD) is an instrument with separate components to be completed at bedtime and waketime. Bedtime components relate to the events of the day preceding the sleep, waketime components to the sleep period just completed. Two-week PghSD data is presented from 234 different subjects, comprising 96 healthy young middle-aged controls, 37 older men, 44 older women, 29 young adult controls and 28 sleep disorders patients in order to demonstrate the usefulness, validity and reliability of various measures from the instrument. Comparisons are made with polysomnographic and actigraphic sleep measures, as well as personality and circadian type questionnaires. The instrument was shown to have sensitivity in detecting differences due to weekends, age, gender, personality and circadian type, and validity in agreeing with actigraphic estimates of sleep timing and quality. Over a 12-31 month delay, PghSD measures of both sleep timing and sleep quality showed correlations between 0.56 and 0.81 (n = 39, P < 0.001).

Effects of Partial and Acute Total Sleep Deprivation on Performance across Cognitive Domains, Individuals and Circadian Phase

PubMed Central

Lo, June C.; Groeger, John A.; Santhi, Nayantara; Arbon, Emma L.; Lazar, Alpar S.; Hasan, Sibah; von Schantz, Malcolm; Archer, Simon N.; Dijk, Derk-Jan

2012-01-01

Background Cognitive performance deteriorates during extended wakefulness and circadian phase misalignment, and some individuals are more affected than others. Whether performance is affected similarly across cognitive domains, or whether cognitive processes involving Executive Functions are more sensitive to sleep and circadian misalignment than Alertness and Sustained Attention, is a matter of debate. Methodology/Principal Findings We conducted a 2 × 12-day laboratory protocol to characterize the interaction of repeated partial and acute total sleep deprivation and circadian phase on performance across seven cognitive domains in 36 individuals (18 males; mean ± SD of age = 27.6±4.0 years). The sample was stratified for the rs57875989 polymorphism in PER3, which confers cognitive susceptibility to total sleep deprivation. We observed a deterioration of performance during both repeated partial and acute total sleep deprivation. Furthermore, prior partial sleep deprivation led to poorer cognitive performance in a subsequent total sleep deprivation period, but its effect was modulated by circadian phase such that it was virtually absent in the evening wake maintenance zone, and most prominent during early morning hours. A significant effect of PER3 genotype was observed for Subjective Alertness during partial sleep deprivation and on n-back tasks with a high executive load when assessed in the morning hours during total sleep deprivation after partial sleep loss. Overall, however, Subjective Alertness and Sustained Attention were more affected by both partial and total sleep deprivation than other cognitive domains and tasks including n-back tasks of Working Memory, even when implemented with a high executive load. Conclusions/Significance Sleep loss has a primary effect on Sleepiness and Sustained Attention with much smaller effects on challenging Working Memory tasks. These findings have implications for understanding how sleep debt and circadian rhythmicity interact to determine waking performance across cognitive domains and individuals. PMID:23029352

[Relationships of positive and negative affectivity to sleep quality in Japanese civil servants: 3-year follow-up study].

PubMed

Saeki, Urara; Nasermoaddeli, Ali; Sekine, Michikazu; Kagamimori, Sadanobu

2008-11-01

We conducted this longitudinal study to evaluate the relationships of positive and negative affectivity (Affect Balance Scale) to sleep quality among civil servants. For this study we evaluated 827 civil servants of T city in Toyama prefecture in the springs of 2001 (Baseline) and 2004 with complete information in both phases of the study. Based on the median score at each phase, we divided Affect Balance Scale (ABS) scores into high and low groups. We conducted logistic regression analysis to determine the odds ratios (OR) of 3-yr follow-up sleep quality by baseline and follow-up ABS scores. After adjusting for baseline sleep quality scores, age, sex, employment, job strain, and exercise habits, participants who had high ABS scores were more likely (OR: 3.13, 95% confidence interval (CI): 1.78-5.53) to have better sleep quality than those with low ABS scores at both phases. In addition, participants with low ABS scores at baseline and high ABS scores 3 yr later had better sleep quality (OR: 1.81, 95%CI: 1.02-3.20) than those with low ABS scores at both phases. These findings substantiate the relationships of positive and negative affectivity to sleep quality. Improving the affect balance condition as well as maintaining good affect balance condition may be important determinants of sleep quality in civil servants.

Interaction of Sleep and Emotional Content on the Production of False Memories

PubMed Central

McKeon, Shannon; Pace-Schott, Edward F.; Spencer, Rebecca M. C.

2012-01-01

Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep’s effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list’s “gist.” Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details. PMID:23145159

What drives sleep-dependent memory consolidation: greater gain or less loss?

PubMed

Fenn, Kimberly M; Hambrick, David Z

2013-06-01

When memory is tested after a delay, performance is typically better if the retention interval includes sleep. However, it is unclear what accounts for this well-established effect. It is possible that sleep enhances the retrieval of information, but it is also possible that sleep protects against memory loss that normally occurs during waking activity. We developed a new research approach to investigate these possibilities. Participants learned a list of paired-associate items and were tested on the items after a 12-h interval that included waking or sleep. We analyzed the number of items gained versus the number of items lost across time. The sleep condition showed more items gained and fewer items lost than did the wake condition. Furthermore, the difference between the conditions (favoring sleep) in lost items was greater than the difference in gain, suggesting that loss prevention may primarily account for the effect of sleep on declarative memory consolidation. This finding may serve as an empirical constraint on theories of memory consolidation.

Managing sleep and wakefulness in a 24-hour world

PubMed Central

Coveney, Catherine M

2014-01-01

This article contributes to literature on the sociology of sleep by exploring the sleeping practices and subjective sleep experiences of two social groups: shift workers and students. It draws on data, collected in the UK from 25 semi-structured interviews, to discuss the complex ways in which working patterns and social activities impact upon experiences and expectations of sleep in our wired awake world. The data show that, typically, sleep is valued and considered to be important for health, general wellbeing, appearance and physical and cognitive functioning. However, sleep time is often cut back on in favour of work demands and social activities. While shift workers described their efforts to fit in an adequate amount of sleep per 24-hour period, for students, the adoption of a flexible sleep routine was thought to be favourable for maintaining a work–social life balance. Collectively, respondents reported using a wide range of strategies, techniques, technologies and practices to encourage, overcome or delay sleep(iness) and boost, promote or enhance wakefulness/alertness at socially desirable times. The analysis demonstrates how social context impacts not only on how we come to think about sleep and understand it, but also how we manage or self-regulate our sleeping patterns. PMID:23957268

The Fate of Incoming Stimuli during NREM Sleep is Determined by Spindles and the Phase of the Slow Oscillation.

PubMed

Schabus, Manuel; Dang-Vu, Thien Thanh; Heib, Dominik Philip Johannes; Boly, Mélanie; Desseilles, Martin; Vandewalle, Gilles; Schmidt, Christina; Albouy, Geneviève; Darsaud, Annabelle; Gais, Steffen; Degueldre, Christian; Balteau, Evelyne; Phillips, Christophe; Luxen, André; Maquet, Pierre

2012-01-01

The present study aimed at identifying the neurophysiological responses associated with auditory stimulation during non-rapid eye movement (NREM) sleep using simultaneous electroencephalography (EEG)/functional magnetic resonance imaging (fMRI) recordings. It was reported earlier that auditory stimuli produce bilateral activation in auditory cortex, thalamus, and caudate during both wakefulness and NREM sleep. However, due to the spontaneous membrane potential fluctuations cortical responses may be highly variable during NREM. Here we now examine the modulation of cerebral responses to tones depending on the presence or absence of sleep spindles and the phase of the slow oscillation. Thirteen healthy young subjects were scanned successfully during stage 2-4 NREM sleep in the first half of the night in a 3 T scanner. Subjects were not sleep-deprived and sounds were post hoc classified according to (i) the presence of sleep spindles or (ii) the phase of the slow oscillation during (±300 ms) tone delivery. These detected sounds were then entered as regressors of interest in fMRI analyses. Interestingly wake-like responses - although somewhat altered in size and location - persisted during NREM sleep, except during present spindles (as previously published in Dang-Vu et al., 2011) and the negative going phase of the slow oscillation during which responses became less consistent or even absent. While the phase of the slow oscillation did not alter brain responses in primary sensory cortex, it did modulate responses at higher cortical levels. In addition EEG analyses show a distinct N550 response to tones during the presence of light sleep spindles and suggest that in deep NREM sleep the brain is more responsive during the positive going slope of the slow oscillation. The presence of short temporal windows during which the brain is open to external stimuli is consistent with the fact that even during deep sleep meaningful events can be detected. Altogether, our results emphasize the notion that spontaneous fluctuations of brain activity profoundly modify brain responses to external information across all behavioral states, including deep NREM sleep.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea.

PubMed

Butler, Matthew P; Smales, Carolina; Wu, Huijuan; Hussain, Mohammad V; Mohamed, Yusef A; Morimoto, Miki; Shea, Steven A

2015-11-01

To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. Within-subject and between-subjects. Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea. © 2015 Associated Professional Sleep Societies, LLC.

An Endogenous Circadian Rhythm in Sleep Inertia Results in Greatest Cognitive Impairment upon Awakening during the Biological Night

PubMed Central

Scheer, Frank A. J. L.; Shea, Thomas J.; Hilton, Michael F.; Shea, Steven A.

2011-01-01

Sleep inertia is the impaired cognitive performance immediately upon awakening, which decays over tens of minutes. This phenomenon has relevance to people who need to make important decisions soon after awakening, such as on-call emergency workers. Such awakenings can occur at varied times of day or night, so the objective of the study was to determine whether or not the magnitude of sleep inertia varies according to the phase of the endogenous circadian cycle. Twelve adults (mean, 24 years; 7 men) with no medical disorders other than mild asthma were studied. Following 2 baseline days and nights, subjects underwent a forced desynchrony protocol composed of seven 28-h sleep/wake cycles, while maintaining a sleep/wakefulness ratio of 1:2 throughout. Subjects were awakened by a standardized auditory stimulus 3 times each sleep period for sleep inertia assessments. The magnitude of sleep inertia was quantified as the change in cognitive performance (number of correct additions in a 2-min serial addition test) across the first 20 min of wakefulness. Circadian phase was estimated from core body temperature (fitted temperature minimum assigned 0°). Data were segregated according to: (1) circadian phase (60° bins); (2) sleep stage; and (3) 3rd of the night after which awakenings occurred (i.e., tertiary 1, 2, or 3). To control for any effect of sleep stage, the circadian rhythm of sleep inertia was initially assessed following awakenings from Stage 2 (62% of awakening occurred from this stage; n = 110). This revealed a significant circadian rhythm in the sleep inertia of cognitive performance (p = 0.007), which was 3.6 times larger during the biological night (circadian bin 300°, ~2300–0300 h in these subjects) than during the biological day (bin 180°, ~1500–1900 h). The circadian rhythm in sleep inertia was still present when awakenings from all sleep stages were included (p = 0.004), and this rhythm could not be explained by changes in underlying sleep drive prior to awakening (changes in sleep efficiency across circadian phase or across the tertiaries), or by the proportion of the varied sleep stages prior to awakenings. This robust endogenous circadian rhythm in sleep inertia may have important implications for people who need to be alert soon after awakening. PMID:18663242

An endogenous circadian rhythm in sleep inertia results in greatest cognitive impairment upon awakening during the biological night.

PubMed

Scheer, Frank A J L; Shea, Thomas J; Hilton, Michael F; Shea, Steven A

2008-08-01

Sleep inertia is the impaired cognitive performance immediately upon awakening, which decays over tens of minutes. This phenomenon has relevance to people who need to make important decisions soon after awakening, such as on-call emergency workers. Such awakenings can occur at varied times of day or night, so the objective of the study was to determine whether or not the magnitude of sleep inertia varies according to the phase of the endogenous circadian cycle. Twelve adults (mean, 24 years; 7 men) with no medical disorders other than mild asthma were studied. Following 2 baseline days and nights, subjects underwent a forced desynchrony protocol composed of seven 28-h sleep/wake cycles, while maintaining a sleep/wakefulness ratio of 1:2 throughout. Subjects were awakened by a standardized auditory stimulus 3 times each sleep period for sleep inertia assessments. The magnitude of sleep inertia was quantified as the change in cognitive performance (number of correct additions in a 2-min serial addition test) across the first 20 min of wakefulness. Circadian phase was estimated from core body temperature (fitted temperature minimum assigned 0 degrees ). Data were segregated according to: (1) circadian phase (60 degrees bins); (2) sleep stage; and (3) 3rd of the night after which awakenings occurred (i.e., tertiary 1, 2, or 3). To control for any effect of sleep stage, the circadian rhythm of sleep inertia was initially assessed following awakenings from Stage 2 (62% of awakening occurred from this stage; n = 110). This revealed a significant circadian rhythm in the sleep inertia of cognitive performance (p = 0.007), which was 3.6 times larger during the biological night (circadian bin 300 degrees , approximately 2300-0300 h in these subjects) than during the biological day (bin 180 degrees , approximately 1500-1900 h). The circadian rhythm in sleep inertia was still present when awakenings from all sleep stages were included (p = 0.004), and this rhythm could not be explained by changes in underlying sleep drive prior to awakening (changes in sleep efficiency across circadian phase or across the tertiaries), or by the proportion of the varied sleep stages prior to awakenings. This robust endogenous circadian rhythm in sleep inertia may have important implications for people who need to be alert soon after awakening.

Thalamic Spindles Promote Memory Formation during Sleep through Triple Phase-Locking of Cortical, Thalamic, and Hippocampal Rhythms.

PubMed

Latchoumane, Charles-Francois V; Ngo, Hong-Viet V; Born, Jan; Shin, Hee-Sup

2017-07-19

While the interaction of the cardinal rhythms of non-rapid-eye-movement (NREM) sleep-the thalamo-cortical spindles, hippocampal ripples, and the cortical slow oscillations-is thought to be critical for memory consolidation during sleep, the role spindles play in this interaction is elusive. Combining optogenetics with a closed-loop stimulation approach in mice, we show here that only thalamic spindles induced in-phase with cortical slow oscillation up-states, but not out-of-phase-induced spindles, improve consolidation of hippocampus-dependent memory during sleep. Whereas optogenetically stimulated spindles were as efficient as spontaneous spindles in nesting hippocampal ripples within their excitable troughs, stimulation in-phase with the slow oscillation up-state increased spindle co-occurrence and frontal spindle-ripple co-occurrence, eventually resulting in increased triple coupling of slow oscillation-spindle-ripple events. In-phase optogenetic suppression of thalamic spindles impaired hippocampus-dependent memory. Our results suggest a causal role for thalamic sleep spindles in hippocampus-dependent memory consolidation, conveyed through triple coupling of slow oscillations, spindles, and ripples. Copyright © 2017 Elsevier Inc. All rights reserved.

The benefits of four weeks of melatonin treatment on circadian patterns in resistance-trained athletes.

PubMed

Leonardo-Mendonça, Roberto C; Martinez-Nicolas, Antonio; de Teresa Galván, Carlos; Ocaña-Wilhelmi, Javier; Rusanova, Iryna; Guerra-Hernández, Eduardo; Escames, Germaine; Acuña-Castroviejo, Darío

2015-01-01

Exercise can induce circadian phase shifts depending on the duration, intensity and frequency. These modifications are of special meaning in athletes during training and competition. Melatonin, which is produced by the pineal gland in a circadian manner, behaves as an endogenous rhythms synchronizer, and it is used as a supplement to promote resynchronization of altered circadian rhythms. In this study, we tested the effect of melatonin administration on the circadian system in athletes. Two groups of athletes were treated with 100 mg day(-1) of melatonin or placebo 30 min before bed for four weeks. Daily rhythm of salivary melatonin was measured before and after melatonin administration. Moreover, circadian variables, including wrist temperature (WT), motor activity and body position rhythmicity, were recorded during seven days before and seven days after melatonin or placebo treatment with the aid of specific sensors placed in the wrist and arm of each athlete. Before treatment, the athletes showed a phase-shift delay of the melatonin circadian rhythm, with an acrophase at 05:00 h. Exercise induced a phase advance of the melatonin rhythm, restoring its acrophase accordingly to the chronotype of the athletes. Melatonin, but not placebo treatment, changed daily waveforms of WT, activity and position. These changes included a one-hour phase advance in the WT rhythm before bedtime, with a longer nocturnal steady state and a smaller reduction when arising at morning than the placebo group. Melatonin, but not placebo, also reduced the nocturnal activity and the activity and position during lunch/nap time. Together, these data reflect the beneficial effect of melatonin to modulate the circadian components of the sleep-wake cycle, improving sleep efficiency.

Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans

PubMed Central

Dijk, Derk-Jan; Duffy, Jeanne F.; Silva, Edward J.; Shanahan, Theresa L.; Boivin, Diane B.; Czeisler, Charles A.

2012-01-01

Background The phase and amplitude of rhythms in physiology and behavior are generated by circadian oscillators and entrained to the 24-h day by exposure to the light-dark cycle and feedback from the sleep-wake cycle. The extent to which the phase and amplitude of multiple rhythms are similarly affected during altered timing of light exposure and the sleep-wake cycle has not been fully characterized. Methodology/Principal Findings We assessed the phase and amplitude of the rhythms of melatonin, core body temperature, cortisol, alertness, performance and sleep after a perturbation of entrainment by a gradual advance of the sleep-wake schedule (10 h in 5 days) and associated light-dark cycle in 14 healthy men. The light-dark cycle consisted either of moderate intensity ‘room’ light (∼90–150 lux) or moderate light supplemented with bright light (∼10,000 lux) for 5 to 8 hours following sleep. After the advance of the sleep-wake schedule in moderate light, no significant advance of the melatonin rhythm was observed whereas, after bright light supplementation the phase advance was 8.1 h (SEM 0.7 h). Individual differences in phase shifts correlated across variables. The amplitude of the melatonin rhythm assessed under constant conditions was reduced after moderate light by 54% (17–94%) and after bright light by 52% (range 12–84%), as compared to the amplitude at baseline in the presence of a sleep-wake cycle. Individual differences in amplitude reduction of the melatonin rhythm correlated with the amplitude of body temperature, cortisol and alertness. Conclusions/Significance Alterations in the timing of the sleep-wake cycle and associated bright or moderate light exposure can lead to changes in phase and reduction of circadian amplitude which are consistent across multiple variables but differ between individuals. These data have implications for our understanding of circadian organization and the negative health outcomes associated with shift-work, jet-lag and exposure to artificial light. PMID:22363414

Napping facilitates word learning in early lexical development.

PubMed

Horváth, Klára; Myers, Kyle; Foster, Russell; Plunkett, Kim

2015-10-01

Little is known about the role that night-time sleep and daytime naps play in early cognitive development. Our aim was to investigate how napping affects word learning in 16-month-olds. Thirty-four typically developing infants were assigned randomly to nap and wake groups. After teaching two novel object-word pairs to infants, we tested their initial performance with an intermodal preferential looking task in which infants are expected to increase their target looking time compared to a distracter after hearing its auditory label. A second test session followed after approximately a 2-h delay. The delay contained sleep for the nap group or no sleep for the wake group. Looking behaviour was measured with an automatic eye-tracker. Vocabulary size was assessed using the Oxford Communicative Development Inventory. A significant interaction between group and session was found in preferential looking towards the target picture. The performance of the nap group increased after the nap, whereas that of the wake group did not change. The gain in performance correlated positively with the expressive vocabulary size in the nap group. These results indicate that daytime napping helps consolidate word learning in infancy. © 2015 European Sleep Research Society.

Comparison of obese adults with poor versus good sleep quality during a functional neuroimaging delay discounting task: A pilot study.

PubMed

Martin, Laura E; Pollack, Lauren; McCune, Ashley; Schulte, Erica; Savage, Cary R; Lundgren, Jennifer D

2015-10-30

This study aimed to determine if obese adults with poor versus good sleep quality demonstrate reduced self-regulatory capacity and different patterns of neural activation when making impulsive monetary choices. Six obese, good quality sleepers (M age=44.7 years, M BMI=38.1 kg/m(2)) were compared to 13 obese, poor quality sleepers (M age=42.6, M BMI=39.2 kg/m(2)) on sleep and eating behavior and brain activation in prefrontal and insular regions while engaging in a delay discounting task during functional magnetic resonance imaging (fMRI). Poor quality sleepers demonstrated significantly lower brain activation in the right inferior frontal gyrus, right middle frontal gyrus, and bilateral insula when making immediate and smaller (impulsive) monetary choices compared to the baseline condition. Behaviorally, poor compared to good quality sleepers reported higher scores in the night eating questionnaire. Obese adults with poor sleep quality demonstrate decreased brain activation in multiple regions that regulate cognitive control and interceptive awareness, possibly reducing self-regulatory capacity when making immediately gratifying decisions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparative Effectiveness of Three Occupational Therapy Sleep Interventions: A Randomized Controlled Study.

PubMed

Gutman, Sharon A; Gregory, Kristin A; Sadlier-Brown, Megan M; Schlissel, Marcy A; Schubert, Allison M; Westover, Lee Ann; Miller, Richard C

2017-01-01

Although sleep intervention is within the domain of occupational therapy, few studies exist supporting practice. Effectiveness of three sleep interventions was compared: Dreampad Pillow®, iRest® meditation, and sleep hygiene. Twenty-nine participants were randomly assigned to the Dreampad Pillow® ( n = 10), iRest® meditation ( n = 9), and sleep hygiene ( n = 10) groups. In Phase 1, all participants used a 7-day sleep hygiene regimen to reduce poor sleep habits. In Phase 2 (14 days), 10 participants used the Dreampad Pillow® and sleep hygiene, nine used the iRest meditation and sleep hygiene, and 10 continued sleep hygiene only. At intervention-end, the iRest meditation group experienced statistically greater time asleep than both the Dreampad Pillow® ( p < .006, d = 1.87) and sleep hygiene groups ( p < .03, d = 1.80). The Dreampad Pillow® group experienced statistically fewer nighttime awakenings than the iRest® meditation ( p < .04, d = -1.53) and sleep hygiene ( p < .004, d = -1.43) groups. No differences were found between groups in perceived sleep quality, length of time needed to fall asleep, and fatigue level next day. This study provides support for sleep interventions within occupational therapy's domain.

Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat.

PubMed

Kalauzi, Aleksandar; Spasic, Sladjana; Petrovic, Jelena; Ciric, Jelena; Saponjic, Jelena

2012-06-01

This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (∆Φ) was calculated for each epoch by averaging theta Fourier component phase shifts, and the ∆Φ values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that ∆Φ increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.

Daily touchscreen use in infants and toddlers is associated with reduced sleep and delayed sleep onset

PubMed Central

Cheung, Celeste H. M.; Bedford, Rachael; Saez De Urabain, Irati R.; Karmiloff-Smith, Annette; Smith, Tim J.

2017-01-01

Traditional screen time (e.g. TV and videogaming) has been linked to sleep problems and poorer developmental outcomes in children. With the advent of portable touchscreen devices, this association may be extending down in age to disrupt the sleep of infants and toddlers, an age when sleep is essential for cognitive development. However, this association has not been demonstrated empirically. This study aims to examine whether frequency of touchscreen use is associated with sleep in infants and toddlers between 6 and 36 months of age. An online survey was administered to 715 parents reporting on child media use (daily exposure to TV and use of touchscreens), sleep patterns (night-time and daytime sleep duration, sleep onset - time to fall asleep, and frequencies of night awakenings). Structural equation models controlling for age, sex, TV exposure and maternal education indicated a significant association between touchscreen use and night-time sleep, daytime sleep and sleep onset. No significant effect was observed for the number of night awakenings. To our knowledge, this is the first report linking the use of touchscreen with sleep problems in infants and toddlers. Future longitudinal studies are needed to clarify the direction of effects and the mechanisms underlying these associations using detailed sleep tracking. PMID:28406474

Evaluation of circadian phenotypes utilizing fibroblasts from patients with circadian rhythm sleep disorders.

PubMed

Hida, A; Ohsawa, Y; Kitamura, S; Nakazaki, K; Ayabe, N; Motomura, Y; Matsui, K; Kobayashi, M; Usui, A; Inoue, Y; Kusanagi, H; Kamei, Y; Mishima, K

2017-04-25

We evaluated the circadian phenotypes of patients with delayed sleep-wake phase disorder (DSWPD) and non-24-hour sleep-wake rhythm disorder (N24SWD), two different circadian rhythm sleep disorders (CRSDs) by measuring clock gene expression rhythms in fibroblast cells derived from individual patients. Bmal1-luciferase (Bmal1-luc) expression rhythms were measured in the primary fibroblast cells derived from skin biopsy samples of patients with DSWPD and N24SWD, as well as control subjects. The period length of the Bmal1-luc rhythm (in vitro period) was distributed normally and was 22.80±0.47 (mean±s.d.) h in control-derived fibroblasts. The in vitro periods in DSWPD-derived fibroblasts and N24SWD-derived fibroblasts were 22.67±0.67 h and 23.18±0.70 h, respectively. The N24SWD group showed a significantly longer in vitro period than did the control or DSWPD group. Furthermore, in vitro period was associated with response to chronotherapy in the N24SWD group. Longer in vitro periods were observed in the non-responders (mean±s.d.: 23.59±0.89 h) compared with the responders (mean±s.d.: 22.97±0.47 h) in the N24SWD group. Our results indicate that prolonged circadian periods contribute to the onset and poor treatment outcome of N24SWD. In vitro rhythm assays could be useful for predicting circadian phenotypes and clinical prognosis in patients with CRSDs.

Impact of sleep restriction on local immune response and skin barrier restoration with and without "multinutrient" nutrition intervention.

PubMed

Smith, Tracey J; Wilson, Marques A; Karl, J Philip; Orr, Jeb; Smith, Carl D; Cooper, Adam D; Heaton, Kristin J; Young, Andrew J; Montain, Scott J

2018-01-01

Systemic immune function is impaired by sleep restriction. However, the impact of sleep restriction on local immune responses and to what extent any impairment can be mitigated by nutritional supplementation is unknown. We assessed the effect of 72-h sleep restriction (2-h nightly sleep) on local immune function and skin barrier restoration of an experimental wound, and determined the influence of habitual protein intake (1.5 g·kg -1 ·day -1 ) supplemented with arginine, glutamine, zinc sulfate, vitamin C, vitamin D3, and omega-3 fatty acids compared with lower protein intake (0.8 g·kg -1 ·day -1 ) without supplemental nutrients on these outcomes. Wounds were created in healthy adults by removing the top layer of less than or equal to eight forearm blisters induced via suction, after adequate sleep (AS) or 48 h of a 72-h sleep restriction period (SR; 2-h nightly sleep). A subset of participants undergoing sleep restriction received supplemental nutrients during and after sleep restriction (SR+). Wound fluid was serially sampled 48 h postblistering to assess local cytokine responses. The IL-8 response of wound fluid was higher for AS compared with SR [area-under-the-curve (log 10 ), 5.1 ± 0.2 and 4.9 ± 0.2 pg/ml, respectively; P = 0.03]; and both IL-6 and IL-8 concentrations were higher for SR+ compared with SR ( P < 0.0001), suggestive of a potentially enhanced early wound healing response. Skin barrier recovery was shorter for AS (4.2 ± 0.9 days) compared with SR (5.0 ± 0.9 days) ( P = 0.02) but did not differ between SR and SR+ ( P = 0.18). Relatively modest sleep disruption delays wound healing. Supplemental nutrition may mitigate some decrements in local immune responses, without detectable effects on wound healing rate. NEW & NOTEWORTHY The data herein characterizes immune function in response to sleep restriction in healthy volunteers with and without nutrition supplementation. We used a unique skin wound model to show that sleep restriction delays skin barrier recovery, and nutrition supplementation attenuates decrements in local immune responses produced by sleep restriction. These findings support the beneficial effects of adequate sleep on immune function. Additional studies are necessary to characterize practical implications for populations where sleep restriction is unavoidable.

Chronic Artificial Blue-Enriched White Light Is an Effective Countermeasure to Delayed Circadian Phase and Neurobehavioral Decrements

PubMed Central

Najjar, Raymond P.; Wolf, Luzian; Taillard, Jacques; Schlangen, Luc J. M.; Salam, Alex

2014-01-01

Studies in Polar Base stations, where personnel have no access to sunlight during winter, have reported circadian misalignment, free-running of the sleep-wake rhythm, and sleep problems. Here we tested light as a countermeasure to circadian misalignment in personnel of the Concordia Polar Base station during the polar winter. We hypothesized that entrainment of the circadian pacemaker to a 24-h light-dark schedule would not occur in all crew members (n = 10) exposed to 100–300 lux of standard fluorescent white (SW) light during the daytime, and that chronic non-time restricted daytime exposure to melanopsin-optimized blue-enriched white (BE) light would establish an a stable circadian phase, in participants, together with increased cognitive performance and mood levels. The lighting schedule consisted of an alternation between SW lighting (2 weeks), followed by a BE lighting (2 weeks) for a total of 9 weeks. Rest-activity cycles assessed by actigraphy showed a stable rest-activity pattern under both SW and BE light. No difference was found between light conditions on the intra-daily stability, variability and amplitude of activity, as assessed by non-parametric circadian analysis. As hypothesized, a significant delay of about 30 minutes in the onset of melatonin secretion occurred with SW, but not with BE light. BE light significantly enhanced well being and alertness compared to SW light. We propose that the superior efficacy of blue-enriched white light versus standard white light involves melanopsin-based mechanisms in the activation of the non-visual functions studied, and that their responses do not dampen with time (over 9-weeks). This work could lead to practical applications of light exposure in working environment where background light intensity is chronically low to moderate (polar base stations, power plants, space missions, etc.), and may help design lighting strategies to maintain health, productivity, and personnel safety. PMID:25072880

Delayed Diagnosis, Range of Severity, and Multiple Sleep Comorbidities: A Clinical and Polysomnographic Analysis of 100 Patients of the Innsbruck Narcolepsy Cohort

PubMed Central

Frauscher, Birgit; Ehrmann, Laura; Mitterling, Thomas; Gabelia, David; Gschliesser, Viola; Brandauer, Elisabeth; Poewe, Werner; Högl, Birgit

2013-01-01

Study Objectives: Narcolepsy is reported to affect 26-56/100,000 in the general population. We aimed to describe clinical and polysomnographic features of a large narcolepsy cohort in order to comprehensively characterize the narcoleptic spectrum. Methods: We performed a chart- and polysomnographybased review of all narcolepsy patients of the Innsbruck narcolepsy cohort. Results: A total of 100 consecutive narcolepsy patients (87 with cataplexy [NC], 13 without cataplexy [N]) were included in the analysis. All subjects had either excessive daytime sleepiness or cataplexy as their initial presenting clinical feature. Age at symptom onset was 20 (6-69) years. Diagnostic delay was 6.5 (0-39) years. The complete narcolepsy tetrad was present in 36/100 patients; 28/100 patients had three cardinal symptoms; 29/100 had two; and 7/100 had only excessive daytime sleepiness. Severity varied broadly with respect to excessive daytime sleepiness (median Epworth Sleepiness Scale score: 18, range 10-24), cataplexy (8-point Likert scale: median 4.5, range 1-8), hypnagogic hallucinations (median 4.5, range 1-7), and sleep paralysis (median 3, range 1-7). Sleep comorbidity was highly prevalent and ranged from sleeprelated movement disorders (n = 55/100), parasomnias (n = 34/100), and sleeprelated breathing disorders (n = 24/100), to insomnia (n = 28/100). REM sleep without atonia or a periodic limb movement in sleep index > 5/h were present in most patients (90/100 and 75/100). A high percentage of narcoleptic patients in the present study had high frequency leg movements (35%) and excessive fragmentary myoclonus (22%). Of the narcolepsy patients with clinical features of REM sleep behavior disorder (RBD), 76.5% had EMG evidence for RBD on the multiple sleep latency test (MSLT), based on a standard cutoff of a minimum of 18% of 3-sec miniepochs. Conclusion: This study is one of the largest monocentric polysomnographic studies to date of patients with narcolepsy and confirms the frequent comorbidity of narcolepsy with many other sleep disorders. Our study is the first to evaluate the percentage of patients with high frequency leg movements and excessive fragmentary myoclonus in narcolepsy and is the first to demonstrate EMG evidence of RBD in the MSLT. These findings add to the growing body of literature suggesting that motor instability is a key feature of narcolepsy. Citation: Frauscher B; Ehrmann L; Mitterling T; Gabelia D; Gschliesser V; Brandauer E; Poewe W; Högl B. Delayed diagnosis, range of severity, and multiple sleep comorbidities: a clinical and polysomnographic analysis of 100 patients of the Innsbruck narcolepsy cohort. J Clin Sleep Med 2013;9(8):805-812. PMID:23946711

A Cryptochrome 2 mutation yields advanced sleep phase in humans.

PubMed

Hirano, Arisa; Shi, Guangsen; Jones, Christopher R; Lipzen, Anna; Pennacchio, Len A; Xu, Ying; Hallows, William C; McMahon, Thomas; Yamazaki, Maya; Ptáček, Louis J; Fu, Ying-Hui

2016-08-16

Familial Advanced Sleep Phase (FASP) is a heritable human sleep phenotype characterized by very early sleep and wake times. We identified a missense mutation in the human Cryptochrome 2 (CRY2) gene that co-segregates with FASP in one family. The mutation leads to replacement of an alanine residue at position 260 with a threonine (A260T). In mice, the CRY2 mutation causes a shortened circadian period and reduced phase-shift to early-night light pulse associated with phase-advanced behavioral rhythms in the light-dark cycle. The A260T mutation is located in the phosphate loop of the flavin adenine dinucleotide (FAD) binding domain of CRY2. The mutation alters the conformation of CRY2, increasing its accessibility and affinity for FBXL3 (an E3 ubiquitin ligase), thus promoting its degradation. These results demonstrate that CRY2 stability controlled by FBXL3 plays a key role in the regulation of human sleep wake behavior.

Experience-dependent phase-reversal of hippocampal neuron firing during REM sleep.

PubMed

Poe, G R; Nitz, D A; McNaughton, B L; Barnes, C A

2000-02-07

The idea that sleep could serve a cognitive function has remained popular since Freud stated that dreams were "not nonsense" but a time to sort out experiences [S. Freud, Letter to Wilhelm Fliess, May 1897, in The Origins of Psychoanalysis - Personal Letters of Sigmund Freud, M. Bonaparte, A. Freud, E. Kris (Eds.), Translated by E. Mosbacher, J. Strachey, Basic Books and Imago Publishing, 1954]. Rapid eye movement (REM) sleep, which is associated with dream reports, is now known to be is important for acquisition of some tasks [A. Karni, D. Tanne, B.S. Rubenstein, J.J.M. Askenasy, D. Sagi, Dependence on REM sleep of overnight improvement of a perceptual skill, Science 265 (1994) 679-682; C. Smith, Sleep states and learning: a review of the animal literature, Biobehav. Rev. 9 (1985) 157-168]; although why this is so remains obscure. It has been proposed that memories may be consolidated during REM sleep or that forgetting of unnecessary material occurs in this state [F. Crick, G. Mitchison, The function of dream sleep, Nature 304 (1983) 111-114; D. Marr, Simple memory: a theory for archicortex, Philos. Trans. R. Soc. B. 262 (1971) 23-81]. We studied the firing of multiple single neurons in the hippocampus, a structure that is important for episodic memory, during familiar and novel experiences and in subsequent REM sleep. Cells active in familiar places during waking exhibited a reversal of firing phase relative to local theta oscillations in REM sleep. Because firing-phase can influence whether synapses are strengthened or weakened [C. Holscher, R. Anwyl, M.J. Rowan, Stimulation on the positive phase of hippocampal theta rhythm induces long-term potentiation that can be depotentiated by stimulation on the negative phase in area CA1 in vivo, J. Neurosci. 15 (1977) 6470-6477; P.T. Huerta, J.E. Lisman, Bidirectional synaptic plasticity induced by a single burst during cholinergic theta oscillation in CA1 in vitro, Neuron 15 (1995) 1053-1063; C. Pavlides, Y.J. Greenstein, M. Grudman, J. Winson, Long-term potentiation in the dentate gyrus is induced preferentially on the positive phase of theta-rhythm, Brain Res. 439 (1988) 383-387] this experience-dependent phase shift, which developed progressively over multiple sessions in the environment, is consistent with the hypothesis that circuits may be restructured during REM sleep by selectively strengthening recently acquired memories and weakening older ones.

Energetic constraints, not predation, influence the evolution of sleep patterning in mammals.

PubMed

Capellini, I; Nunn, C L; McNamara, P; Preston, B T; Barton, R A

2008-10-01

Mammalian sleep is composed of two distinct states - rapid-eye-movement (REM) and non-REM (NREM) sleep - that alternate in cycles over a sleep bout. The duration of these cycles varies extensively across mammalian species. Because the end of a sleep cycle is often followed by brief arousals to waking, a shorter sleep cycle has been proposed to function as an anti-predator strategy. Similarly, higher predation risk could explain why many species exhibit a polyphasic sleep pattern (division of sleep into several bouts per day), as having multiple sleep bouts avoids long periods of unconsciousness, potentially reducing vulnerability.Using phylogenetic comparative methods, we tested these predictions in mammals, and also investigated the relationships among sleep phasing, sleep-cycle length, sleep durations and body mass.Neither sleep-cycle length nor phasing of sleep was significantly associated with three different measures of predation risk, undermining the idea that they represent anti-predator adaptations.Polyphasic sleep was associated with small body size, shorter sleep cycles and longer sleep durations. The correlation with size may reflect energetic constraints: small animals need to feed more frequently, preventing them from consolidating sleep into a single bout. The reduced daily sleep quotas in monophasic species suggests that the consolidation of sleep into one bout per day may deliver the benefits of sleep more efficiently and, since early mammals were small-bodied and polyphasic, a more efficient monophasic sleep pattern could be a hitherto unrecognized advantage of larger size.

Increased Disease Activity is Associated with Altered Sleep Architecture in an Experimental Model of Systemic Lupus Erythematosus

PubMed Central

Palma, Beatriz Duarte; Tufik, Sergio

2010-01-01

Study Objectives: The aim of this study was to evaluate sleep patterns during the course of the disease in (NZB/NZW)F1 mice, an experimental model of systemic lupus erythematosus (SLE). Design: Female mice were implanted with electrodes for chronic recording of sleep-wake cycles during the entire experimental phase (9, 19, and 29 weeks of age). The disease course was also assessed. At each time-point, blood samples were collected from the orbital plexus to evaluate serum antinuclear antibodies (ANA), which are important serologic parameters of disease evolution. Pain perception was also evaluated. Measurements and Results: During the dark phase, (NZB/NZW)F1 mice aged 19 weeks spent more time in sleep, and, as a consequence, the total waking time was lower when compared with earlier periods. An augmented number of sleep-stage transitions and microarousals were observed at the 29th week of life in both light and dark phases. At this same time-point, the mice showed lower pain thresholds than they had at 9 weeks of life. The disease status was confirmed; the entire group of mice at 29 weeks of life showed positive ANA with high titer levels. Conclusions: The sleep-recording data showed that, during the progress and severe phases of the disease (19 and 29 wks of age, respectively), sleep architecture is altered. According to these results, increased sleep fragmentation, disease activity, and pain sensitivity are features observed in these mice, similar to symptoms of SLE. Citation: Palma BD; Tufik S. Increased disease activity is associated with altered sleep architecture in an experimental model of systemic lupus erythematosus. SLEEP 2010;33(9):1244-1248. PMID:20857872

Role of REM Sleep, Melanin Concentrating Hormone and Orexin/Hypocretin Systems in the Sleep Deprivation Pre-Ischemia

PubMed Central

Pace, Marta; Adamantidis, Antoine; Facchin, Laura; Bassetti, Claudio

2017-01-01

Study Objectives Sleep reduction after stroke is linked to poor recovery in patients. Conversely, a neuroprotective effect is observed in animals subjected to acute sleep deprivation (SD) before ischemia. This neuroprotection is associated with an increase of the sleep, melanin concentrating hormone (MCH) and orexin/hypocretin (OX) systems. This study aims to 1) assess the relationship between sleep and recovery; 2) test the association between MCH and OX systems with the pathological mechanisms of stroke. Methods Sprague-Dawley rats were assigned to four experimental groups: (i) SD_IS: SD performed before ischemia; (ii) IS: ischemia; (iii) SD_Sham: SD performed before sham surgery; (iv) Sham: sham surgery. EEG and EMG were recorded. The time-course of the MCH and OX gene expression was measured at 4, 12, 24 hours and 3, 4, 7 days following ischemic surgery by qRT-PCR. Results A reduction of infarct volume was observed in the SD_IS group, which correlated with an increase of REM sleep observed during the acute phase of stroke. Conversely, the IS group showed a reduction of REM sleep. Furthermore, ischemia induces an increase of MCH and OX systems during the acute phase of stroke, although, both systems were still increased for a long period of time only in the SD_IS group. Conclusions Our data indicates that REM sleep may be involved in the neuroprotective effect of SD pre-ischemia, and that both MCH and OX systems were increased during the acute phase of stroke. Future studies should assess the role of REM sleep as a prognostic marker, and test MCH and OXA agonists as new treatment options in the acute phase of stroke. PMID:28061506

Sleep and circadian rhythms in long duration space flight - Antarctica as an analogue environment

NASA Technical Reports Server (NTRS)

Gander, Philippa H.

1992-01-01

The feasibility of using Antarctica as an environment for studying the impact of unusual 24 h environmental cycles (zeitgebers) on the circadian system is discussed. Adaptation of circadian rhythms and sleep of three scientists travelling from New Zealand to Antarctica during summer (which is analogous to arrival at a lunar base during the lunar day) has been studied. Data obtained indicate that sleep occurred at the same clock time, but sleep quality was poorer in Antarctica, which can be explained by the fact that the circadian system delayed by about 2 h in Antarctica, as would be expected in a weaker zeitgeber environment. It is suggested that sleep could be improved by altering patterns of exposure to the available zeitgebers to increase their effective strength.

Electronic media use and sleep in school-aged children and adolescents: A review.

PubMed

Cain, Neralie; Gradisar, Michael

2010-09-01

Electronic media have often been considered to have a negative impact on the sleep of children and adolescents, but there are no comprehensive reviews of research in this area. The present study identified 36 papers that have investigated the relationship between sleep and electronic media in school-aged children and adolescents, including television viewing, use of computers, electronic gaming, and/or the internet, mobile telephones, and music. Many variables have been investigated across these studies, although delayed bedtime and shorter total sleep time have been found to be most consistently related to media use. A model of the mechanisms by which media use may affect sleep is presented and discussed as a vehicle for future research. Copyright 2010 Elsevier B.V. All rights reserved.

The missing link between sleep disorders and age-related dementia: recent evidence and plausible mechanisms.

PubMed

Zhang, Feng; Zhong, Rujia; Li, Song; Chang, Raymond Chuen-Chung; Le, Weidong

2017-05-01

Sleep disorders are among the most common clinical problems and possess a significant concern for the geriatric population. More importantly, while around 40% of elderly adults have sleep-related complaints, sleep disorders are more frequently associated with co-morbidities including age-related neurodegenerative diseases and mild cognitive impairment. Recently, increasing evidence has indicated that disturbed sleep may not only serve as the consequence of brain atrophy, but also contribute to the pathogenesis of dementia and, therefore, significantly increase dementia risk. Since the current therapeutic interventions lack efficacies to prevent, delay or reverse the pathological progress of dementia, a better understanding of underlying mechanisms by which sleep disorders interact with the pathogenesis of dementia will provide possible targets for the prevention and treatment of dementia. In this review, we briefly describe the physiological roles of sleep in learning/memory, and specifically update the recent research evidence demonstrating the association between sleep disorders and dementia. Plausible mechanisms are further discussed. Moreover, we also evaluate the possibility of sleep therapy as a potential intervention for dementia.

Declarative and Non-declarative Memory Consolidation in Children with Sleep Disorder.

PubMed

Csábi, Eszter; Benedek, Pálma; Janacsek, Karolina; Zavecz, Zsófia; Katona, Gábor; Nemeth, Dezso

2015-01-01

Healthy sleep is essential in children's cognitive, behavioral, and emotional development. However, remarkably little is known about the influence of sleep disorders on different memory processes in childhood. Such data could give us a deeper insight into the effect of sleep on the developing brain and memory functions and how the relationship between sleep and memory changes from childhood to adulthood. In the present study we examined the effect of sleep disorder on declarative and non-declarative memory consolidation by testing children with sleep-disordered breathing (SDB) which is characterized by disrupted sleep structure. We used a story recall task to measure declarative memory and Alternating Serial Reaction time (ASRT) task to assess non-declarative memory. This task enables us to measure two aspects of non-declarative memory, namely general motor skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 12 h offline period with sleep. Our data showed that children with SDB exhibited a generally lower declarative memory performance both in the learning and testing phase; however, both the SDB and control groups exhibited retention of the previously recalled items after the offline period. Here we showed intact non-declarative consolidation in SDB group in both sequence-specific and general motor skill. These findings suggest that sleep disorders in childhood have a differential effect on different memory processes (online vs. offline) and give us insight into how sleep disturbances affects developing brain.

Declarative and Non-declarative Memory Consolidation in Children with Sleep Disorder

PubMed Central

Csábi, Eszter; Benedek, Pálma; Janacsek, Karolina; Zavecz, Zsófia; Katona, Gábor; Nemeth, Dezso

2016-01-01

Healthy sleep is essential in children’s cognitive, behavioral, and emotional development. However, remarkably little is known about the influence of sleep disorders on different memory processes in childhood. Such data could give us a deeper insight into the effect of sleep on the developing brain and memory functions and how the relationship between sleep and memory changes from childhood to adulthood. In the present study we examined the effect of sleep disorder on declarative and non-declarative memory consolidation by testing children with sleep-disordered breathing (SDB) which is characterized by disrupted sleep structure. We used a story recall task to measure declarative memory and Alternating Serial Reaction time (ASRT) task to assess non-declarative memory. This task enables us to measure two aspects of non-declarative memory, namely general motor skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 12 h offline period with sleep. Our data showed that children with SDB exhibited a generally lower declarative memory performance both in the learning and testing phase; however, both the SDB and control groups exhibited retention of the previously recalled items after the offline period. Here we showed intact non-declarative consolidation in SDB group in both sequence-specific and general motor skill. These findings suggest that sleep disorders in childhood have a differential effect on different memory processes (online vs. offline) and give us insight into how sleep disturbances affects developing brain. PMID:26793090

Short Blue Light Pulses (30 Min) in the Morning Support a Sleep-Advancing Protocol in a Home Setting.

PubMed

Geerdink, Moniek; Walbeek, Thijs J; Beersma, Domien G M; Hommes, Vanja; Gordijn, Marijke C M

2016-10-01

Many people in our modern civilized society sleep later on free days compared to work days. This discrepancy in sleep timing will lead to so-called 'social jetlag' on work days with negative consequences for performance and health. Light therapy in the morning is often proposed as the most effective method to advance the circadian rhythm and sleep phase. However, most studies focus on direct effects on the circadian system and not on posttreatment effects on sleep phase and sleep integrity. In this placebo-controlled home study we investigated if blue light, rather than amber light therapy, can phase shift the sleep phase along with the circadian rhythm with preservation of sleep integrity and performance. We selected 42 participants who suffered from 'social jetlag' on workdays. Participants were randomly assigned to either high-intensity blue light exposure or amber light exposure (placebo) with similar photopic illuminance. The protocol consisted of 14 baseline days without sleep restrictions, 9 treatment days with either 30-min blue light pulses or 30-min amber light pulses in the morning along with a sleep advancing scheme and 7 posttreatment days without sleep restrictions. Melatonin samples were taken at days 1, 7, 14 (baseline), day 23 (effect treatment), and day 30 (posttreatment). Light exposure was recorded continuously. Sleep was monitored through actigraphy. Performance was measured with a reaction time task. As expected, the phase advance of the melatonin rhythm from day 14 to day 23 was significantly larger in the blue light exposure group, compared to the amber light group (84 min ± 51 (SD) and 48 min ± 47 (SD) respectively; t36 = 2.23, p < 0.05). Wake-up time during the posttreatment days was slightly earlier compared to baseline in the blue light group compared to slightly later in the amber light group (-21 min ± 33 (SD) and +12 min ± 33 (SD) respectively; F1,35 = 9.20, p < 0.01). The number of sleep bouts was significantly higher in the amber light group compared to the blue light group during sleep in the treatment period (F1,32 = 4.40, p < 0.05). Performance was significantly worse compared to baseline at all times during (F1,13 = 10.1, p < 0.01) and after amber light treatment (F1,13 = 17.1, p < 0.01), while only in the morning during posttreatment in the blue light condition (F1,10 = 9.8, p < 0.05). The data support the conclusion that blue light was able to compensate for the sleep integrity reduction and to a large extent for the performance decrement that was observed in the amber light condition, both probably as a consequence of the advancing sleep schedule. This study shows that blue light therapy in the morning, applied in a home setting, supports a sleep advancing protocol by phase advancing the circadian rhythm as well as sleep timing. © 2016 The Author(s).

Age-related change in the association between a polymorphism in the PER3 gene and preferred timing of sleep and waking activities.

PubMed

Jones, Kay H S; Ellis, Jason; von Schantz, Malcolm; Skene, Debra J; Dijk, Derk-Jan; Archer, Simon N

2007-03-01

The objective of this study was to investigate the effect of age on the association between preferred timing of sleep and waking activities and a coding-region variable number tandem repeat (VNTR) polymorphism in the clock gene PER3. We have previously reported this polymorphism to associate with diurnal preference and delayed sleep phase syndrome (DSPS). Participants (n = 1590; 707 males and 883 females) completed the Horne-Ostberg (HO) questionnaire for diurnal preference and provided a DNA sample. Overall HO scores were plotted against age. The 5% extremes and intermediates were selected for genotyping. Frequencies of the PER3 4- and 5-repeat alleles were examined in separate age groups (18-29, 30-39, 40-49 and 50+ years of age). The 4-repeat allele was significantly more frequent in evening types, and the 5-repeat allele more frequent in morning types (Fisher's exact test, P = 0.016). Analysis in the four age groupings revealed that the strength of this association attenuated with age and was significant only in the youngest group (18-29 years). These results extend our previous finding of an association between the PER3 VNTR and diurnal preference. They also demonstrate that diurnal preference in young people is more closely associated with this polymorphism than it is in other age groups.

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay.

PubMed

Tassino, Bettina; Horta, Stefany; Santana, Noelia; Levandovski, Rosa; Silva, Ana

2016-01-01

In humans, a person's chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals' chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light-dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration.

Auditory feedback blocks memory benefits of cueing during sleep

PubMed Central

Schreiner, Thomas; Lehmann, Mick; Rasch, Björn

2015-01-01

It is now widely accepted that re-exposure to memory cues during sleep reactivates memories and can improve later recall. However, the underlying mechanisms are still unknown. As reactivation during wakefulness renders memories sensitive to updating, it remains an intriguing question whether reactivated memories during sleep also become susceptible to incorporating further information after the cue. Here we show that the memory benefits of cueing Dutch vocabulary during sleep are in fact completely blocked when memory cues are directly followed by either correct or conflicting auditory feedback, or a pure tone. In addition, immediate (but not delayed) auditory stimulation abolishes the characteristic increases in oscillatory theta and spindle activity typically associated with successful reactivation during sleep as revealed by high-density electroencephalography. We conclude that plastic processes associated with theta and spindle oscillations occurring during a sensitive period immediately after the cue are necessary for stabilizing reactivated memory traces during sleep. PMID:26507814

Circadian rhythms and risk for substance use disorders in adolescence

PubMed Central

Hasler, Brant P.; Soehner, Adriane M.; Clark, Duncan B.

2014-01-01

Purpose of the review This article explores recent research in adolescent circadian rhythms, neurobiological changes influencing affective regulation and reward responding, and the emergence of substance use and related problems. Recent findings Recent findings have confirmed that adolescents with drug and alcohol problems are also beset by sleep problems, and have advanced our understanding of the relationship between sleep problems and substance involvement in this developmental period. During adolescence, a shift to later preferred sleep times interacts with early school start times to cause sleep loss and circadian misalignment. Sleep loss and circadian misalignment may disrupt reward-related brain function and impair inhibitory control. Deficits or delays in mature reward and inhibitory functions may contribute to adolescent alcohol use and other substance involvement. Summary An integration of the available research literature suggests that changes in sleep and circadian rhythms during adolescence may contribute to accelerated substance use and related problems. PMID:25247459

A global quantification of “normal” sleep schedules using smartphone data

PubMed Central

Walch, Olivia J.; Cochran, Amy; Forger, Daniel B.

2016-01-01

The influence of the circadian clock on sleep scheduling has been studied extensively in the laboratory; however, the effects of society on sleep remain largely unquantified. We show how a smartphone app that we have developed, ENTRAIN, accurately collects data on sleep habits around the world. Through mathematical modeling and statistics, we find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep. A country’s average bedtime, but not average wake time, predicts sleep duration. We further show that mathematical models based on controlled laboratory experiments predict qualitative trends in sunrise, sunset, and light level; however, these effects are attenuated in the real world around bedtime. Additionally, we find that women schedule more sleep than men and that users reporting that they are typically exposed to outdoor light go to sleep earlier and sleep more than those reporting indoor light. Finally, we find that age is the primary determinant of sleep timing, and that age plays an important role in the variability of population-level sleep habits. This work better defines and personalizes “normal” sleep, produces hypotheses for future testing in the laboratory, and suggests important ways to counteract the global sleep crisis. PMID:27386531

[Habits and problems of sleep in adolescent students].

PubMed

Lazaratou, E; Dikeos, D; Anagnostopoulos, D; Soldatos, C

2008-07-01

The evaluation of sleep habits and sleep related problems in high school adolescent students in the Athens area and the assessment of these problems' relation to demographic and other variables was investigated by the Athens Insomnia Scale - 5 item version (AIS-5), which was administered to 713 adolescent Senior High School students in the Greater Athens Area. Data such as age, sex, school records, and time spent per week in school-related and extracurricular activities were collected. The sample's mean sleep duration was 7,5 hours, mean bedtime 12:20 am and wake-up time 7:15 am. Total sleep time was not affected by gender, but was influenced by time spent in various activities. Sleep complaints were related to delayed sleep, onset latency and insufficient total duration of sleep. Girls complained more than boys, while correlations showed that students with lower academic per formance and those in second grade were more likely to have higher AIS-5 scores. The results show that sleep time of high school students is dependent on practical matters such as school schedule and other activities, while sleep complaints are related to female gender, bad school performance as well as to the second grade. The difference between actual sleep time and sleep complaints should be considered when studying the sleep of adolescents.

Co-Sleeping among School-Aged Anxious and Non-Anxious Children: Associations with Sleep Variability and Timing.

PubMed

Palmer, Cara A; Clementi, Michelle A; Meers, Jessica M; Alfano, Candice A

2018-01-05

Little is known about the co-sleeping behaviors of school-aged children, particularly among anxious youth who commonly present for the treatment of sleep problems. The current study examined the occurrence of co-sleeping in both healthy and clinically anxious children and its associated sleep patterns. A total of 113 children (ages 6-12), 75 with primary generalized anxiety disorder and 38 healthy controls, participated along with their primary caregiver. Families completed structured diagnostic assessments, and parents reported on their child's co-sleeping behaviors and anxiety severity. Children provided reports of anxiety severity and completed one week of wrist-based actigraphy to assess objective sleep patterns. A significantly greater proportion of anxious youth compared to healthy children co-slept, and greater anxiety severity was related to more frequent co-sleeping. Co-sleeping in anxious youth was associated with a delay in sleep timing and with greater sleep variability (i.e., more variable nightly sleep duration). All analyses controlled for child age, race/ethnicity, family income, and parental marital status. Co-sleeping is highly common in anxious school-aged children, with more than 1 in 3 found to co-sleep at least sometimes (2-4 times a week). Co-sleeping was even more common for youth with greater anxiety severity. Increased dependence on others to initiate and maintain sleep may contribute to poorer sleep in this population via shifted schedules and more variable sleep patterns.

Parkinsonian syndromes presenting with circadian rhythm sleep disorder- advanced sleep-phase type.

PubMed

Shukla, Garima; Kaul, Bhavna; Gupta, Anupama; Goyal, Vinay; Behari, Madhuri

2015-01-01

Circadian rhythm sleep disorder-advanced sleep-phase type is a relatively uncommon disorder, mostly seen among the elderly population. Impaired circadian rhythms have been reported in neurodegenerative conditions; however, there are no reports of any circadian rhythm sleep disorder among patients with Parkinsonian syndromes. We report two patients who presented with this circadian rhythm disorder, and were then diagnosed with a Parkinsonian syndrome. The cases. A 65-year-old retired man presented with history of abrupt change in sleep schedules, sleeping around 6.30-7 p.m. and waking up around 3-4 a.m. for the last 2 months. On detailed examination, the patient was observed to have symmetrical bradykinesia and cogwheel rigidity of limbs. A diagnosis of multiple system atrophy was made, supported by MRI findings and evidence of autonomic dysfunction. Symptoms of change in sleep-wake cycles resolved over the next 1 year, while the patient was treated with dopaminergic therapy. A 47-year-old man, who was being evaluated for presurgical investigation for refractory temporal lobe epilepsy, presented with complaints suggestive of dysarthria, bradykinesia of limbs and frequent falls for 5 months. Simultaneously, he began to sleep around 7 p.m. and wake up at about 2-3 a.m. Examination revealed severe axial rigidity, restricted vertical gaze and bradykinesia of limbs. A diagnosis of progressive supranuclear palsy was made. This is the first report of Parkinson's plus syndromes presenting with a circadian rhythm sleep disorder-advanced sleep-phase type. More prospective assessment for circadian sleep disorders may introduce useful insights into similar associations. Copyright 2015, NMJI.

Chronotype, Light Exposure, Sleep, and Daytime Functioning in High School Students Attending Morning or Afternoon School Shifts: An Actigraphic Study.

PubMed

Martin, Jeanne Sophie; Gaudreault, Michael M; Perron, Michel; Laberge, Luc

2016-04-01

Adolescent maturation is associated with delays of the endogenous circadian phase. Consequently, early school schedules may lead to a mismatch between internal and external time, which can be detrimental to adolescent sleep and health. In parallel, chronotype is known to play a role in adolescent health; evening chronotype adolescents are at higher risk for sleep problems and lower academic achievement. In the summer of 2008, Kénogami High School (Saguenay, Canada) was destroyed by fire. Kénogami students were subsequently relocated to Arvida High School (situated 5.3 km away) for the 2008-2009 academic year. A dual school schedule was implemented, with Arvida students attending a morning schedule (0740-1305 h) and Kénogami students an afternoon schedule (1325-1845 h). This study aimed to investigate the effects of such school schedules and chronotype on sleep, light exposure, and daytime functioning. Twenty-four morning and 33 afternoon schedule students wore an actigraph during 7 days to measure sleep and light exposure. Academic achievement was obtained from school. Subjects completed validated questionnaires on daytime sleepiness, psychological distress, social rhythms, school satisfaction, alcohol, and chronotype. Overall, afternoon schedule students had longer sleep duration, lower sleepiness, and lower light exposure than morning schedule students. Evening chronotypes (E-types) reported higher levels of sleepiness than morning chronotypes (M-types) in both morning and afternoon schedules. Furthermore, M-types attending the morning schedule reported higher sleepiness than M-types attending the afternoon schedule. No difference was found between morning and afternoon schedule students with regard to academic achievement, psychological distress, social rhythms, school satisfaction, and alcohol consumption. However, in both schedules, M-type had more regular social rhythms and lower alcohol consumption. In summary, this study emphasizes that an early school schedule is associated with detrimental effects in terms of sleep deprivation and daytime sleepiness, even for M-types. Furthermore, irrespective of school schedule, E-type adolescents face an increased risk for poor daytime functioning. © 2016 The Author(s).

A control system formulation of the mechanism that controls the secretions of serum group hormone in humans during sleep

NASA Technical Reports Server (NTRS)

Howard, J. C.; Young, D. R.

1975-01-01

Plasma growth hormone concentrations during sleep were determined experimentally. An elevated level of plasma growth hormone was observed during the initial phase of sleep and remained elevated for approximately 3 hr before returning to the steady-state level. Moreover, subsequent to a prolonged interruption of sleep, of the order of 2-3 hr, an elevated level of plasma growth hormone was again observed during the initial phase of resumed sleep. A control system formulation of the mechanism that controls the secretions of serum growth hormone in humans was used to account for the growth hormone responses observed.

Two pedigrees of familial advanced sleep phase syndrome in Japan.

PubMed

Satoh, Kohtoku; Mishima, Kazuo; Inoue, Yuichi; Ebisawa, Takashi; Shimizu, Tetsuo

2003-06-15

To determine whether a known missense mutation (bp2106 A/G) in hPer2 (a human homolog of the Drosophila period gene) for familial advanced sleep phase syndrome in a Caucasian family is involved in Japanese familial advanced sleep phase syndrome pedigrees. We identified 2 new Japanese families with advanced sleep phase syndrome, and a systematic survey was carried out in 28 relatives of theses 2 families. A total of 9 affected subjects were identified. The affected members showed significantly strong morningness tendencies compared with the unaffected members in various circadian parameters including the Horne-Ostberg Morningness-Eveningness Questionnaire score (77.3 +/- 4.8 vs 57.5 +/- 7.6, p < 0.001), average sleep-onset time (20:45 +/- 75 min vs 23:16 +/- 64 min, p < 0.02), and average wake time (4:55 +/- 38 min vs 6:13 +/- 25 min, p < 0.01), as well as saliva dim-light melatonin-onset time (20:15 +/- 21 min vs 22:25 +/- 65 min, p < 0.02). DNA samples were obtained from 7 affected and 7 unaffected subjects. None of the tested subjects possessed the missense mutation (bp2106 A/G) in hPer2. Furthermore, there is no significant linkage between affected subjects with hPer2 region by 2-point mapping and by direct sequencing of 23 exons of hPer2. These findings support the notion of genetic heterogeneity of familial advanced sleep phase syndrome cases in humans. The search for more familial advanced sleep phase syndrome cases and for loci other than hPer2 are necessary to further examine the roles of circadian-related genes in genetically determined human circadian rhythm disorders.

Sleep difficulties and academic performance in Norwegian higher education students.

PubMed

Hayley, Amie C; Sivertsen, Børge; Hysing, Mari; Vedaa, Øystein; Øverland, Simon

2017-12-01

Sleep difficulties are common among university students and may detrimentally affect academic outcomes. Despite this, remarkably little information is currently available during this critical developmental period of early adulthood, and thus, the direct effect on measurable domains of academic ability and proficiency is equivocal. To evaluate the associations between difficulties initiating and maintaining sleep (DIMS) and subjective and objective academic performance in a large sample of university students. A total of 12,915 students who participated in large student survey in Norway from 24 February 2014 to 27 March 2014. DIMS was assessed by the Hopkins Symptoms Checklist (HSCL-25), and academic outcomes included failed examinations, delayed study progress, and school-related self-efficacy (General Self-Efficacy Scale). Difficulties initiating and maintaining sleep was independently associated with increased odds for poor school performance for all academic outcomes. Reporting 'extreme' DIMS was associated with increased odds of reporting delayed study progress (adjusted odds ratio [OR] = 1.25, 95% CI 1.01-1.57, p < .05), increased odds for having failed several examinations (adjusted OR = 1.91, 95% CI 1.56-2.34, p < .001), and being in the lowest self-efficacy quartile (adjusted OR = 4.94, 95% CI: 4.04-6.03, p < .001). Self-reported sleep difficulties are associated with poorer objective markers of academic outcomes as well as poorer self-rated academic proficiency among higher education students. Amelioration of sleep difficulties may improve overall academic performance and health outcomes in affected students. © 2017 The British Psychological Society.

Prospection and emotional memory: how expectation affects emotional memory formation following sleep and wake

PubMed Central

Cunningham, Tony J.; Chambers, Alexis M.; Payne, Jessica D.

2014-01-01

Successful prospective memory is necessarily driven by an expectation that encoded information will be relevant in the future, leading to its preferential placement in memory storage. Like expectation, emotional salience is another type of cue that benefits human memory formation. Although separate lines of research suggest that both emotional information and information explicitly expected to be important in the future benefit memory consolidation, it is unknown how expectation affects the processing of emotional information and whether sleep, which is known to maximize memory consolidation, plays a critical role. The purpose of this study was to investigate how expectation would impact the consolidation of emotionally salient content, and whether this impact would differ across delays of sleep and wake. Participants encoded scenes containing an emotionally charged negative or neutral foreground object placed on a plausible neutral background. After encoding, half of the participants were informed they would later be tested on the scenes (expected condition), while the other half received no information about the test (unexpected condition). At recognition, following a 12-h delay of sleep or wakefulness, the scene components (objects and backgrounds) were presented separately and one at a time, and participants were asked to determine if each component was old or new. Results revealed a greater disparity for memory of negative objects over their paired neutral backgrounds for both the sleep and wake groups when the memory test was expected compared to when it was unexpected, while neutral memory remained unchanged. Analyzing each group separately, the wake group showed a threefold increase in the magnitude of this object/background trade-off for emotional scenes when the memory test was expected compared to when it was unexpected, while those who slept performed similarly across conditions. These results suggest that emotional salience and expectation cues interact to benefit emotional memory consolidation during a delay of wakefulness. The sleeping brain, however, may automatically tag emotionally salient information as important, such that explicit instruction of an upcoming memory test does not further improve memory performance. PMID:25136328

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea

PubMed Central

Butler, Matthew P.; Smales, Carolina; Wu, Huijuan; Hussain, Mohammad V.; Mohamed, Yusef A.; Morimoto, Miki; Shea, Steven A.

2015-01-01

Study Objective: To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. Design: Within-subject and between-subjects. Settings: Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. Participants: Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. Interventions: Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. Measurements and Results: Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. Conclusions: The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea. Citation: Butler MP, Smales C, Wu H, Hussain MV, Mohamed YA, Morimoto M, Shea SA. The circadian system contributes to apnea lengthening across the night in obstructive sleep apnea. SLEEP 2015;38(11):1793–1801. PMID:26039970

Impact of sleep inertia on visual selective attention for rare targets and the influence of chronotype.

PubMed

Ritchie, Hannah K; Burke, Tina M; Dear, Tristan B; Mchill, Andrew W; Axelsson, John; Wright, Kenneth P

2017-10-01

Sleep inertia is affected by circadian phase, with worse performance upon awakening from sleep during the biological night than biological day. Visual search/selective visual attention performance is known to be sensitive to sleep inertia and circadian phase. Individual differences exist in the circadian timing of habitual wake time, which may contribute to individual differences in sleep inertia. Because later chronotypes awaken at an earlier circadian phase, we hypothesized that later chronotypes would have worse visual search performance during sleep inertia than earlier chronotypes if awakened at habitual wake time. We analysed performance from 18 healthy participants [five females (22.1 ± 3.7 years; mean ± SD)] at ~1, 10, 20, 30, 40 and 60 min following electroencephalogram-verified awakening from an 8 h in-laboratory sleep opportunity. Cognitive throughput and reaction times of correct responses were impaired by sleep inertia and took ~10-30 min to improve after awakening. Regardless whether chronotype was defined by dim light melatonin onset or mid-sleep clock hour on free days, derived from the Munich ChronoType Questionnaire, the duration of sleep inertia for cognitive throughput and reaction times was longer for later chronotypes (n = 7) compared with earlier chronotypes (n = 7). Specifically, performance for earlier chronotypes showed significant improvement within ~10-20 min after awakening, whereas performance for later chronotypes took ~30 min or longer to show significant improvement (P < 0.05). Findings have implications for decision making immediately upon awakening from sleep, and are consistent with circadian theory suggesting that sleep inertia contributes to longer-lasting impairments in morning performance in later chronotypes. © 2017 European Sleep Research Society.

Sleep and circadian rhythms in children and adolescents: relevance for athletic performance of young people.

PubMed

Carskadon, Mary A

2005-04-01

The amount and timing of sleep play significant roles in forming a solid foundation for competitive performance in young athletes. As children mature into and through adolescence, their need for sleep does not decline substantially, although the opportunity to sleep is limited by lifestyle choices, academic and practice schedules, and compelling changes in the biological processes. The biological changes include a more "permissive" pace for the accumulation of sleep pressure across the day in older adolescents and a longer day length in the more mature. These factors all favor later bedtimes and rising times as children pass into adolescence, and a concomitant delay in the optimal timing for waking activities. Among the important threats to athletic performance are insufficient sleep during training and competition and poor appreciation for the best time of day for competitive activities. The specific consequences of these issues for individual athletes are not clear, though when considering young people as a group, support for adequate sleep is a rational intervention to maximize performance.

Changes in sleep theta rhythm are related to episodic memory impairment in early Alzheimer's disease.

PubMed

Hot, Pascal; Rauchs, Géraldine; Bertran, Françoise; Denise, Pierre; Desgranges, Béatrice; Clochon, Patrice; Eustache, Francis

2011-07-01

Impairments have been reported both in sleep structure and episodic memory in Alzheimer's disease [AD]. Our objective was to investigate the relationships between episodic memory deficits and electro-encephalography [EEG] abnormalities occurring during sleep in patients with early AD. Postlearning sleep was recorded in 14 patients with mild to moderate AD, and 14 healthy elderly controls after they performed an episodic memory task derived from the Grober and Buschke's procedure. For each sleep stage, the relative power and mean frequency in each band were analyzed. Relative to agematched controls, AD patients presented faster mean theta frequency in both REM sleep and slow wave sleep [SWS]. In AD patients, a correlative analysis revealed that faster theta frequency during SWS was associated with better delayed episodic recall. We assume that increased theta activity reflects changes in neuronal activity to maintain memory performance, indicating that compensatory mechanisms already described at the waking state could also be engaged during SWS. Copyright © 2011 Elsevier B.V. All rights reserved.

Melatonin for sleep disturbance in children with neurodevelopmental disorders: prospective observational naturalistic study.

PubMed

Ayyash, Hani F; Preece, Phillip; Morton, Richard; Cortese, Samuele

2015-06-01

Although melatonin is increasingly used for sleep disturbances in children with neurodevelopmental disorders, evidence on effective dose and impact on specific types of sleep disturbance is limited. We assessed 45 children (35 males, mean age: 6.3 ± 1.7 years) with neurodevelopmental disorders (n = 29: intellectual disability; n = 9: autism spectrum disorder; n = 7: attention-deficit/hyperactivity disorder) and sleep disturbances, treated with melatonin (mean duration: 326 days) with doses increased according to response. Thirty-eight percent of children responded to low (2.5-3 mg), 31% to medium (5-6 mg) and 9% to high doses (9-10 mg) of melatonin, with a significant increase in total hours of sleep/night, decreased sleep onset delay and decreased number of awakenings/night (all: p = 0.001), as measured with sleep diaries. No serious adverse events were reported. Melatonin is generally effective and safe in children with neurodevelopmental conditions. Increasing above 6 mg/night adds further benefit only in a small percentage of children.

Sleeping Habits among School Children and their Effects on Sleep Pattern.

PubMed

Mishra, Apurva; Pandey, Ramesh Kumar; Minz, Anurag; Arora, Varuni

2017-12-01

Introduction: Sleep problems can occur at any age. Inadequate sleep affects the physiological as well as psychological well-being of an individual. Thus, the objective of the present study is, to determine the pre sleep habits, duration and pattern of sleep among school children and to determine association between their sleep schedules and sleep habits. Methods: This cross-sectional study comprised of 1050 children attending the government school. Based on inclusion and exclusion criteria children were from three age groups: 4-5 years, 6-10 years and 11-15 years of age. A questionnaire about demographical data, sleep problems and habits, was duly filled by the parents. The parents of children were questioned for bed time, wakeup time, sleep time and sleep duration during both weekdays and weekends. Results: Total sleep time during weekdays was 8.9 (1.2) hours and 10.7 (1.1) hours during weekends. The wakeup time was significantly delayed during weekends in all age groups. Moreover, total sleep time increased significantly during weekends in all age groups. Children using media after 8 pm and sleeping alone are also in significant sleep debt. Screen activities such as TV, internet and cellular phones in a child's bedroom had a negative effect on children's sleep/wake patterns and duration of sleep. Children in higher grades are sleep debt compared to younger ones. Practices such as co sleeping and sharing bed with parents significantly improve the duration and quality of sleep. Conclusion: The sleep durations reported in the present study were lower than recommended sleep duration for children.

The effect of intermittent fasting during Ramadan on sleep, sleepiness, cognitive function, and circadian rhythm.

PubMed

Qasrawi, Shaden O; Pandi-Perumal, Seithikurippu R; BaHammam, Ahmed S

2017-09-01

Studies have shown that experimental fasting can affect cognitive function, sleep, and wakefulness patterns. However, the effects of experimental fasting cannot be generalized to fasting during Ramadan due to its unique characteristics. Therefore, there has been increased interest in studying the effects of fasting during Ramadan on sleep patterns, daytime sleepiness, cognitive function, sleep architecture, and circadian rhythm. In this review, we critically discuss the current research findings in those areas during the month of Ramadan. Available data that controlled for sleep/wake schedule, sleep duration, light exposure, and energy expenditure do not support the notion that Ramadan intermittent fasting increases daytime sleepiness and alters cognitive function. Additionally, recent well-designed studies showed no effect of fasting on circadian rhythms. However, in non-constrained environments that do not control for lifestyle changes, studies have demonstrated sudden and significant delays in bedtime and wake time. Studies that controlled for environmental factors and sleep/wake schedule reported no significant disturbances in sleep architecture. Nevertheless, several studies have consistently reported that the main change in sleep architecture during fasting is a reduction in the proportion of REM sleep.

Sleep disorder among medical students: relationship to their academic performance.

PubMed

Abdulghani, Hamza M; Alrowais, Norah A; Bin-Saad, Norah S; Al-Subaie, Nourah M; Haji, Alhan M A; Alhaqwi, Ali I

2012-01-01

Medical students are exposed to a significant level of pressure due to academic demands. Their sleep pattern is characterized by insufficient sleep duration, delayed sleep onset, and occurrence of napping episodes during the day. To examine the prevalence of sleep disorder among medical students and investigate any relationship between sleep disorder and academic performance. This is a cross-sectional self-administered questionnaire-based study. The participants were medical students of the first, second, and third academic years. The Epworth Sleepiness Scale (ESS) was also included to identify sleep disorder and grade point average was recorded for academic performance. There were 491 responses with a response rate of 55%. The ESS score demonstrated that 36.6% of participants were considered to have abnormal sleep habits, with a statistically significant increase in female students (p = 0.000). Sleeping between 6-10 h per day was associated with normal ESS scores (p = 0.019) as well as the academic grades ≥ 3.75. Abnormal ESS scores were associated with lower academic achievement (p = 0.002). A high prevalence of sleep disorder was found in this group of students, specifically female students. Analysis of the relationship between sleep disorder and academic performance indicates a significant relationship between abnormal ESS scores, total sleeping hours, and academic performance.

The effects of partial sleep restriction and altered sleep timing on olfactory performance.

PubMed

McNeil, J; Forest, G; Hintze, L J; Brunet, J-F; Doucet, É

2017-12-01

Olfaction can increase the drive to eat and may partially explain the consistent increases in energy intake (EI) following sleep restriction. We investigated the effects of 50% sleep restriction with altered sleep timing on olfactory performance. We also evaluated whether changes (Δ) in olfactory performance were associated with Δ24 h EI. Twelve men and six women (age: 23±4 years; BMI: 23±3 kg/m 2 ) completed three randomized cross-over conditions: habitual sleep duration, 50% sleep restriction with advanced wake-time, and 50% sleep restriction with delayed bedtime. Sleep was measured in-laboratory (polysomnography). Olfactory performance ('sniffin sticks') and 24 h EI (food menu) were evaluated the next day. A trend for a significant condition*sex interaction was noted for threshold-discrimination-identification (TDI) scores (P=0.09); TDI scores were lowest in women and highest in men, following sleep restriction with advanced wake-time. Δolfactory performance were not associated with Δ24 h EI. The impact of sleep restriction on olfactory performance may differ between sexes. Changes in olfactory performance were not associated with changes in 24 h EI. Studies investigating prolonged effects of sleep loss on the relationship between olfactory performance with EI are needed.

Esophageal sensation in premature human neonates: temporal relationships and implications of aerodigestive reflexes and electrocortical arousals

PubMed Central

Parks, Vanessa N.; Peng, Juan; Dzodzomenyo, Samuel; Fernandez, Soledad; Shaker, Reza; Splaingard, Mark

2012-01-01

Electrocortical arousal (ECA) as an effect of visceral provocation or of its temporal relationships with aerodigestive reflexes in premature neonates is not known. We tested the hypothesis that esophageal provocation results in both esophageal reflex responses and ECAs during sleep and that ECAs are dependent on the frequency characteristics of esophageal neuromotor responses. We defined the spatiotemporal relationship of ECAs in relation to 1) spontaneous pharyngoesophageal swallow sequences and gastroesophageal reflux (GER) events and 2) sensory-motor characteristics of esophageal reflexes. Sixteen healthy premature neonates born at 27.9 ± 3.4 wk were tested at 36.8 ± 1.9 wk postmenstrual age. Ninety-five midesophageal and 31 sham stimuli were given in sleep during concurrent manometry and videopolysomnography. With stimulus onset as reference point, we scored the response latency, frequency occurrence and duration of arousals, peristaltic reflex, and upper esophageal sphincter contractile reflex (UESCR). Changes in polysomnography-respiratory patterns and esophageal sensory-motor parameters were scored by blinded observers. Significantly (for each characteristic listed, P < 0.05), swallow sequences were associated with arousals and sleep state changes, and arousals were associated with incomplete peristalsis, response delays to lower esophageal sphincter relaxation, and prolonged esophageal clearance. GER events (73.5%) provoked arousals, and arousals were associated with response delays to peristaltic reflexes or clearance, sleep state modification, and prolonged respiratory arousal. Midesophageal stimuli (54%) provoked arousals and were associated with increased frequency, prolonged latency, prolonged response duration of peristaltic reflexes and UESCR, and increased frequency of sleep state changes and respiratory arousals. In human neonates, ECAs are provoked upon esophageal stimulation; the sensory-motor characteristics of esophageal reflexes are distinct when accompanied by arousals. Aerodigestive homeostasis is defended by multiple tiers of aerodigestive safety mechanisms, and when esophageal reflexes are delayed, cortical hypervigilance (ECAs) occurs. PMID:21852361

Circadian misalignment, reward-related brain function, and adolescent alcohol involvement.

PubMed

Hasler, Brant P; Clark, Duncan B

2013-04-01

Developmental changes in sleep and circadian rhythms that occur during adolescence may contribute to reward-related brain dysfunction, and consequently increase the risk of alcohol use disorders (AUDs). This review (i) describes marked changes in circadian rhythms, reward-related behavior and brain function, and alcohol involvement that occur during adolescence, (ii) offers evidence that these parallel developmental changes are associated, and (iii) posits a conceptual model by which misalignment between sleep-wake timing and endogenous circadian timing may increase the risk of adolescent AUDs by altering reward-related brain function. The timing of sleep shifts later throughout adolescence, in part due to developmental changes in endogenous circadian rhythms, which tend to become more delayed. This tendency for delayed sleep and circadian rhythms is at odds with early school start times during secondary education, leading to misalignment between many adolescents' sleep-wake schedules and their internal circadian timing. Circadian misalignment is associated with increased alcohol use and other risk-taking behaviors, as well as sleep loss and sleep disturbance. Growing evidence indicates that circadian rhythms modulate the reward system, suggesting that circadian misalignment may impact adolescent alcohol involvement by altering reward-related brain function. Neurocognitive function is also subject to sleep and circadian influence, and thus circadian misalignment may also impair inhibitory control and other cognitive processes relevant to alcohol use. Specifically, circadian misalignment may further exacerbate the cortical-subcortical imbalance within the reward circuit, an imbalance thought to explain increased risk-taking and sensation-seeking during adolescence. Adolescent alcohol use is highly contextualized, however, and thus studies testing this model will also need to consider factors that may influence both circadian misalignment and alcohol use. This review highlights growing evidence supporting a path by which circadian misalignment may disrupt reward mechanisms, which may in turn accelerate the transition from alcohol use to AUDs in vulnerable adolescents. Copyright © 2013 by the Research Society on Alcoholism.

The Sleep–Wake Cycle in the Nicotinic Alpha-9 Acetylcholine Receptor Subunit Knock-Out Mice

PubMed Central

Madrid-López, Natalia; Estrada, Jorge; Díaz, Javier; Bassi, Alejandro; Délano, Paul H.; Ocampo-Garcés, Adrián

2017-01-01

There is a neural matrix controlling the sleep–wake cycle (SWC) embedded within high ranking integrative mechanisms in the central nervous system. Nicotinic alpha-9 acetylcholine receptor subunit (alpha-9 nAChR) participate in physiological processes occurring in sensory, endocrine and immune systems. There is a relationship between the SWC architecture, body homeostasis and sensory afferents so that disruption of afferent signaling is expected to affect the temporal organization of sleep and wake states. The analysis of the SWC of 9 nAChR knock-out animals may help to reveal the contribution of alpha-9 nAChR to sleep chronobiological determinants. Here we explore the polysomnogram in chronically implanted alpha-9 nAChR knock-out (KO) and wild-type (WT) individuals of the hybrid CBA/Sv129 mouse strain. Records were obtained in isolation chambers under a stable 12:12 light:dark cycle (LD). To unmask the 24-h modulation of the SWC a skeleton photoperiod (SP) protocol was performed. Under LD the daily quota (in %) of wakefulness (W), NREM sleep and REM sleep obtained in KO and WT animals were 45, 48 and 7, and 46, 46 and 8 respectively. Both groups exhibit nocturnal phase preference of W as well as diurnal and unimodal phase preference of NREM and REM sleep. The acrophase mean angles of KO vs. WT genotypes were not different (Zeitgeber Time: 6.5 vs. 14.9 for W, 4.3 vs. 2.8 for NREM sleep and 5.3 vs. 3.4 for REM sleep, respectively). Transference to SP do not affect daily state quotas, phase preferences and acrophases among genotypes. Unmasking phenomena of the SWC such as wake increment during the rest phase under SP was evident only among WT mice suggesting the involvement of retinal structures containing alpha-9 nAChR in masking processes. Furthermore, KO animals exhibit longer NREM and REM sleep episodes that is independent of illumination conditions. Consolidated diurnal NREM sleep contributed to obtain higher values of NREM sleep delta-EEG activity among KO mice during rest phase. In conclusion, circadian and sleep homeostatic aspects of the SWC are operative among alpha-9 nAChR KO animals. We propose that alpha-9 nAChR participate in retinal signaling processes responsible of the positive masking of sleep by light. PMID:29066952

Low Latency MAC Protocol in Wireless Sensor Networks Using Timing Offset

NASA Astrophysics Data System (ADS)

Choi, Seung Sik

This paper proposes a low latency MAC protocol that can be used in sensor networks. To extend the lifetime of sensor nodes, the conventional solution is to synchronize active/sleep periods of all sensor nodes. However, due to these synchronized sensor nodes, packets in the intermediate nodes must wait until the next node wakes up before it can forward a packet. This induces a large delay in sensor nodes. To solve this latency problem, a clustered sensor network which uses two types of sensor nodes and layered architecture is considered. Clustered heads in each cluster are synchronized with different timing offsets to reduce the sleep delay. Using this concept, the latency problem can be solved and more efficient power usage can be obtained.

Sleep-Dependent Oscillatory Synchronization: A Role in Fear Memory Consolidation.

PubMed

Totty, Michael S; Chesney, Logan A; Geist, Phillip A; Datta, Subimal

2017-01-01

Sleep plays an important role in memory consolidation through the facilitation of neuronal plasticity; however, how sleep accomplishes this remains to be completely understood. It has previously been demonstrated that neural oscillations are an intrinsic mechanism by which the brain precisely controls neural ensembles. Inter-regional synchronization of these oscillations is also known to facilitate long-range communication and long-term potentiation (LTP). In the present study, we investigated how the characteristic rhythms found in local field potentials (LFPs) during non-REM and REM sleep play a role in emotional memory consolidation. Chronically implanted bipolar electrodes in the lateral amygdala (LA), dorsal and ventral hippocampus (DH, VH), and the infra-limbic (IL), and pre-limbic (PL) prefrontal cortex were used to record LFPs across sleep-wake activity following each day of a Pavlovian cued fear conditioning paradigm. This resulted in three principle findings: (1) theta rhythms during REM sleep are highly synchronized between regions; (2) the extent of inter-regional synchronization during REM and non-REM sleep is altered by FC and EX; (3) the mean phase difference of synchronization between the LA and VH during REM sleep predicts changes in freezing after cued fear extinction. These results both oppose a currently proposed model of sleep-dependent memory consolidation and provide a novel finding which suggests that the role of REM sleep theta rhythms in memory consolidation may rely more on the relative phase-shift between neural oscillations, rather than the extent of phase synchronization.

Brainwave entrainment for better sleep and post-sleep state of young elite soccer players - a pilot study.

PubMed

Abeln, Vera; Kleinert, Jens; Strüder, Heiko K; Schneider, Stefan

2014-01-01

The effect of sleep deprivation on psychophysical performance and well-being is comprehensively investigated. Research investigating the effect of improved sleep is rare. Just as little exists about attempts to support athletic mental state and performance by improving sleep quality. This study aims to investigate whether sleep quality of top athletes can be improved by auditory brainwave entrainment and whether this leads to enhancements of post-sleep psychophysical states. In a pilot study, 15 young elite soccer players were stimulated for eight weeks during sleep with binaural beats around 2-8 Hz. Once a week after wake-up, participants completed three different questionnaires: a sleep diary, an adjective list for psychophysical and motivational state, and a self-assessment questionnaire for sleep and awakening quality. Fifteen sport students executed the same protocol sleeping on the same pillow, but without stimulation. Subjective ratings of sleep and awakening quality, sleepiness and motivational state were significantly improved only in the intervention group, but did not impact their perceived physical state. In summary, eight weeks of auditory stimulation with binaural beats improved perceived sleep quality and the post-sleep state of athletes, whereas the effect on physical level is assumed to occur in a time-delayed fashion. It seems to be worthwhile - to further elaborate long-time effects and consequences on physical and mental performance.

Sound Asleep: Processing and Retention of Slow Oscillation Phase-Targeted Stimuli

PubMed Central

Cox, Roy; Korjoukov, Ilia; de Boer, Marieke; Talamini, Lucia M.

2014-01-01

The sleeping brain retains some residual information processing capacity. Although direct evidence is scarce, a substantial literature suggests the phase of slow oscillations during deep sleep to be an important determinant for stimulus processing. Here, we introduce an algorithm for predicting slow oscillations in real-time. Using this approach to present stimuli directed at both oscillatory up and down states, we show neural stimulus processing depends importantly on the slow oscillation phase. During ensuing wakefulness, however, we did not observe differential brain or behavioral responses to these stimulus categories, suggesting no enduring memories were formed. We speculate that while simpler forms of learning may occur during sleep, neocortically based memories are not readily established during deep sleep. PMID:24999803

Sound asleep: processing and retention of slow oscillation phase-targeted stimuli.

PubMed

Cox, Roy; Korjoukov, Ilia; de Boer, Marieke; Talamini, Lucia M

2014-01-01

The sleeping brain retains some residual information processing capacity. Although direct evidence is scarce, a substantial literature suggests the phase of slow oscillations during deep sleep to be an important determinant for stimulus processing. Here, we introduce an algorithm for predicting slow oscillations in real-time. Using this approach to present stimuli directed at both oscillatory up and down states, we show neural stimulus processing depends importantly on the slow oscillation phase. During ensuing wakefulness, however, we did not observe differential brain or behavioral responses to these stimulus categories, suggesting no enduring memories were formed. We speculate that while simpler forms of learning may occur during sleep, neocortically based memories are not readily established during deep sleep.

Effects of school start time on students' sleep duration, daytime sleepiness, and attendance: a meta-analysis.

PubMed

Bowers, Jennifer M; Moyer, Anne

2017-12-01

Research conducted over the past three decades finds that many children and adolescents do not meet recommended sleep guidelines. Lack of sleep is a predictor of a number of consequences, including issues at school such as sleepiness and tardiness. Considering the severity of this public health issue, it is essential to understand more about the factors that may compromise children's and adolescents' sleep. This meta-analysis examined the effects of school start time (SST) on sleep duration of students by aggregating the results of five longitudinal studies and 15 cross-sectional comparison group studies. Results indicated that later starting school times are associated with longer sleep durations. Additionally, later start times were associated with less daytime sleepiness (7 studies) and tardiness to school (3 studies). However, methodological considerations, such as a need for more longitudinal primary research, lead to a cautious interpretation. Overall, this systematic analysis of SST studies suggests that delaying SST is associated with benefits for students' sleep and, thus, their general well-being. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Digital Media and Sleep in Childhood and Adolescence.

PubMed

LeBourgeois, Monique K; Hale, Lauren; Chang, Anne-Marie; Akacem, Lameese D; Montgomery-Downs, Hawley E; Buxton, Orfeu M

2017-11-01

Given the pervasive use of screen-based media and the high prevalence of insufficient sleep among American youth and teenagers, this brief report summarizes the literature on electronic media and sleep and provides research recommendations. Recent systematic reviews of the literature reveal that the vast majority of studies find an adverse association between screen-based media consumption and sleep health, primarily via delayed bedtimes and reduced total sleep duration. The underlying mechanisms of these associations likely include the following: (1) time displacement (ie, time spent on screens replaces time spent sleeping and other activities); (2) psychological stimulation based on media content; and (3) the effects of light emitted from devices on circadian timing, sleep physiology, and alertness. Much of our current understanding of these processes, however, is limited by cross-sectional, observational, and self-reported data. Further experimental and observational research is needed to elucidate how the digital revolution is altering sleep and circadian rhythms across development (infancy to adulthood) as pathways to poor health, learning, and safety outcomes (eg, obesity, depression, risk-taking). Copyright © 2017 by the American Academy of Pediatrics.

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay

PubMed Central

Tassino, Bettina; Horta, Stefany; Santana, Noelia; Levandovski, Rosa; Silva, Ana

2016-01-01

In humans, a person’s chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals’ chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light–dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration. PMID:27226819

The Effects of Sleep Continuity Disruption on Positive Mood and Sleep Architecture in Healthy Adults.

PubMed

Finan, Patrick H; Quartana, Phillip J; Smith, Michael T

2015-11-01

The purpose of this study was to test an experimental model of the effects of sleep continuity disturbance on sleep architecture and positive mood in order to better understand the mechanisms linking insomnia and depression. Participants were randomized to receive 3 consecutive nights of sleep continuity disruption via forced nocturnal awakenings (FA, n = 21), or one of two control conditions: restricted sleep opportunity (RSO, n = 17) or uninterrupted sleep (US, n = 24). The study was set in an inpatient clinical research suite. Healthy, good-sleeping men and women were included. Polysomnography was used to measure sleep architecture, and mood was assessed via self-report each day. Compared to restricted sleep opportunity controls, forced awakenings subjects had significantly less slow wave sleep (P < 0.05) after the first night of sleep deprivation, and significantly lower positive mood (P < 0.05) after the second night of sleep deprivation. The differential change in slow wave sleep statistically mediated the observed group differences in positive mood (P = 0.002). To our knowledge, this is the first human experimental study to demonstrate that, despite comparable reductions in total sleep time, partial sleep loss from sleep continuity disruption is more detrimental to positive mood than partial sleep loss from delaying bedtime, even when controlling for concomitant increases in negative mood. With these findings, we provide temporal evidence in support of a putative biologic mechanism (slow wave sleep deficit) that could help explain the strong comorbidity between insomnia and depression. © 2015 Associated Professional Sleep Societies, LLC.

Experimental Evidence for Phase Synchronization Transitions in the Human Cardiorespiratory System

NASA Astrophysics Data System (ADS)

Bartsch, Ronny; Kantelhardt, Jan W.; Penzel, Thomas; Havlin, Shlomo

2007-02-01

Transitions in the dynamics of complex systems can be characterized by changes in the synchronization behavior of their components. Taking the human cardiorespiratory system as an example and using an automated procedure for screening the synchrograms of 112 healthy subjects we study the frequency and the distribution of synchronization episodes under different physiological conditions that occur during sleep. We find that phase synchronization between heartbeat and breathing is significantly enhanced during non-rapid-eye-movement (non-REM) sleep (deep sleep and light sleep) and reduced during REM sleep. Our results suggest that the synchronization is mainly due to a weak influence of the breathing oscillator upon the heartbeat oscillator, which is disturbed in the presence of long-term correlated noise, superimposed by the activity of higher brain regions during REM sleep.

Sleep, Hormones, and Circadian Rhythms throughout the Menstrual Cycle in Healthy Women and Women with Premenstrual Dysphoric Disorder.

PubMed

Shechter, Ari; Boivin, Diane B

2010-01-01

A relationship exists between the sleep-wake cycle and hormone secretion, which, in women, is further modulated by the menstrual cycle. This interaction can influence sleep across the menstrual cycle in healthy women and in women with premenstrual dysphoric disorder (PMDD), who experience specific alterations of circadian rhythms during their symptomatic luteal phase along with sleep disturbances during this time. This review will address the variation of sleep at different menstrual phases in healthy and PMDD women, as well as changes in circadian rhythms, with an emphasis on their relationship with female sex hormones. It will conclude with a brief discussion on nonpharmacological treatments of PMDD which use chronotherapeutic methods to realign circadian rhythms as a means of improving sleep and mood in these women.

Sleep quality in medical students: a comparison across the various phases of the medical course

PubMed Central

Corrêa, Camila de Castro; de Oliveira, Felipe Kazan; Pizzamiglio, Diego Scherlon; Ortolan, Erika Veruska Paiva; Weber, Silke Anna Theresa

2017-01-01

ABSTRACT Objective: To evaluate and compare subjective sleep quality in medical students across the various phases of the medical course. Methods: This was a cross-sectional study involving medical undergraduates at one medical school in the city of Botucatu, Brazil. All first- to sixth-year students were invited to complete the Pittsburgh Sleep Quality Index, which has been validated for use in Brazil. Participants were divided into three groups according to the phase of the medical course: group A (first- and second-years); group B (third- and fourth-years); and group C (fifth- and sixth-years). The results obtained for the instrument components were analyzed for the total sample and for the groups. Results: Of the 540 students invited to participate, 372 completed the instrument fully. Of those, 147 (39.5%) reported their sleep quality to be either very or fairly bad; 110 (29.5%) reported taking more than 30 min to fall asleep; 253 (68.0%) reported sleeping 6-7 h per night; 327 (87.9%) reported adequate sleep efficiency; 315 (84.6%) reported no sleep disturbances; 32 (8.6%) reported using sleeping medication; and 137 (36.9%) reported difficulty staying awake during the day at least once a week. Group comparison revealed that students in group A had worse subjective sleep quality and greater daytime dysfunction than did those in groups B and C. Conclusions: Medical students seem to be more exposed to sleep disturbance than other university students, and first- and second-years are more affected than those in other class years because they have worse subjective sleep quality. Active interventions should be implemented to improve sleep hygiene in medical students. PMID:29365004

Association between elder abuse and poor sleep: A cross-sectional study among rural older Malaysians.

PubMed

Yunus, Raudah Mohd; Wazid, Syeda Wasfeea; Hairi, Noran N; Choo, Wan Yuen; Hairi, Farizah M; Sooryanarayana, Rajini; Ahmad, Sharifah N; Razak, Inayah A; Peramalah, Devi; Aziz, Suriyati A; Mohamad, Zaiton L; Mohamad, Rosmala; Ali, Zainudin M; Bulgiba, Awang

2017-01-01

To examine the association between elder abuse and poor sleep using a Malay validated version of Pittsburgh Sleep Quality Index (PSQI). This study was divided into two phases. Phase I tested the construct validity and reliability of the Malay version of PSQI. Phase II was a population-based, cross-sectional study with a multi-stage cluster sampling method. Home-based interviews were conducted by trained personnel using a structured questionnaire, to determine exposure and outcome. Kuala Pilah, a district in Negeri Sembilan which is one of the fourteen states in Malaysia. 1648 community-dwelling older Malaysians. The Malay version of PSQI had significant test re-test reliability with intra-class correlation coefficients of 0.62. Confirmatory factor analyses revealed that one factor PSQI scale with three components (subjective sleep quality, sleep latency, and sleep disturbances) was most suitable. Cronbach's Alpha was 0.60 and composite reliability was 0.63. PSQI scores were highest among neglect (4.11), followed by physical (4.10), psychological (3.96) and financial abuse (3.60). There was a dose-response relationship between clustering of abuse and PSQI scores; 3.41, 3.50 and 3.84 for "no abuse", "1 type of abuse" and "2 types or more". Generalized linear models revealed six variables as significant determinants of sleep quality-abuse, co-morbidities, self-rated health, income, social support and gait speed. Among abuse subtypes, only neglect was significantly associated with poor sleep. The Malay PSQI was valid and reliable. Abuse was significantly associated with poor sleep. As sleep is essential for health and is a good predictor for mortality among older adults, management of abuse victims should entail sleep assessment. Interventions or treatment modalities which focus on improving sleep quality among abuse victims should be designed.

Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training

PubMed Central

Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

2011-01-01

This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was divided into the initial spatial learning phase (3.5 d) immediately followed by the reversal phase (2.5 d). During the 6 h following four or 12 training trials/day of initial or reversal learning phases, REM sleep was eliminated and non-REM sleep left intact using the multiple inverted flowerpot method. Contrary to our hypotheses, REM sleep deprivation during four or 12 trials/day of initial spatial or reversal learning did not affect training performance. However, some probe trial measures indicated REM sleep-deprivation–associated impairment in initial spatial learning with four trials/day and enhancement of subsequent reversal learning. In naive animals, REM sleep deprivation during normal initial spatial learning was followed by a lack of preference for the subsequent reversal platform location during the probe. Our findings contradict reports that REM sleep is essential for spatial learning in the Morris water maze and newly reveal that short periods of REM sleep deprivation do not impair concurrent reversal learning. Effects on subsequent reversal learning are consistent with the idea that REM sleep serves the consolidation of incompletely learned items. PMID:21677190

The Neuroprotective Aspects of Sleep.

PubMed

Eugene, Andy R; Masiak, Jolanta

2015-03-01

Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of sleep is a serious concern that people need to be aware of. When one sleeps, the brain reorganizes and recharges itself, and removes toxic waste byproducts which have accumulated throughout the day. This evidence demonstrates that sleeping can clear the brain and help maintain its normal functioning. Multiple studies have been done to determine the effects of total sleep deprivation; more recently some have been conducted to show the effects of sleep restriction, which is a much more common occurrence, have the same effects as total sleep deprivation. Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment. As a background for this paper we have reviewed literature and research of sleep phases, effects of sleep deprivation, and the glymphatic system of the brain and its restorative effect during the sleep cycle.

The Neuroprotective Aspects of Sleep

PubMed Central

Eugene, Andy R.; Masiak, Jolanta

2015-01-01

Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of sleep is a serious concern that people need to be aware of. When one sleeps, the brain reorganizes and recharges itself, and removes toxic waste byproducts which have accumulated throughout the day. This evidence demonstrates that sleeping can clear the brain and help maintain its normal functioning. Multiple studies have been done to determine the effects of total sleep deprivation; more recently some have been conducted to show the effects of sleep restriction, which is a much more common occurrence, have the same effects as total sleep deprivation. Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment. As a background for this paper we have reviewed literature and research of sleep phases, effects of sleep deprivation, and the glymphatic system of the brain and its restorative effect during the sleep cycle. PMID:26594659

Relationship of chronotype to sleep pattern in a cohort of college students during work days and vacation days.

PubMed

Yadav, Arjita; Singh, Sudhi

2014-05-01

To study whether the chronotype is linked with the sleep characteristics among college going students assessed during college days and vacation days, adult female students at undergraduate level were asked to answer the Hindi/English version of the Munich Chronotype Questionnaire (MCTQ), fill a sleep log, and drinking and feeding logs for three weeks covering college and vacation days. Based on chronotype categorization as morning type, intermediate type and evening type, sleep onset and offset times, sleep duration and mid-sleep times for each group were compared, separately for college and vacation days. Results indicate that the sleep duration of the morning types was significantly longer than the evening types, both, during college and vacation days. Similarly, the sleep onset and sleep offset times were significantly earlier in the morning types than the evening type students. During the vacation days, the individuals exhibited longer sleep duration with delayed mid-sleep times. Further there was no significant difference among the chronotypes regarding their feeding and drinking frequency per cent during the college and the vacation days. It is suggested that the students should be made aware of their chronotype, so that they can utilize their time optimally, and develop a schedule more suitable to their natural needs.

Identifying some determinants of "jet lag" and its symptoms: a study of athletes and other travellers.

PubMed

Waterhouse, J; Edwards, B; Nevill, A; Carvalho, S; Atkinson, G; Buckley, P; Reilly, T; Godfrey, R; Ramsay, R

2002-02-01

Travelling across multiple time zones disrupts normal circadian rhythms and induces "jet lag". Possible effects of this on training and performance in athletes were concerns before the Sydney Olympic Games. To identify some determinants of jet lag and its symptoms. A mixture of athletes, their coaches, and academics attending a conference (n = 85) was studied during their flights from the United Kingdom to Australia (two flights with a one hour stopover in Singapore), and for the first six days in Australia. Subjects differed in age, sex, chronotype, flexibility of sleeping habits, feelings of languor, fitness, time of arrival in Australia, and whether or not they had previous experience of travel to Australia. These variables and whether the body clock adjusted to new local time by phase advance or delay were tested as predictors for jet lag and some of its symptoms by stepwise multiple regression analyses. The amount of sleep in the first flight was significantly greater in those who had left the United Kingdom in the evening than the morning (medians of 5.5 hours and 1.5 hours respectively; p = 0.0002, Mann-Whitney), whereas there was no significant difference on the second flight (2.5 hours v 2.8 hours; p = 0.72). Only the severity of jet lag and assessments of sleep and fatigue were commonly predicted significantly (p<0.05) by regression analysis, and then by only some of the variables. Thus increasing age and a later time of arrival in Australia were associated with less jet lag and fatigue, and previous experience of travel to Australia was associated with an earlier time of getting to sleep. Subjects who had adjusted by phase advance suffered worse jet lag during the 5th and 6th days in Australia. These results indicate the importance of an appropriate choice of itinerary and lifestyle for reducing the negative effects of jet lag in athletes and others who wish to perform optimally in the new time zone.

Transitions in Physiologic Coupling: Sleep Stage and Age Dependence of Cardio-respiratory Phase Synchronization

NASA Astrophysics Data System (ADS)

Bartsch, Ronny P.; Ivanov, Plamen Ch.

2012-02-01

Recent studies have focused on various features of cardiac and respiratory dynamics with the aim to better understand key aspects of the underlying neural control of these systems. We investigate how sleep influences cardio-respiratory coupling, and how the degree of this coupling changes with transitions across sleep stages in healthy young and elderly subjects. We analyze full night polysomnographic recordings of 189 healthy subjects (age range: 20 to 90 years). To probe cardio-respiratory coupling, we apply a novel phase synchronization analysis method to quantify the adjustment of rhythms between heartbeat and breathing signals. We investigate how cardio-respiratory synchronization changes with sleep-stage transitions and under healthy aging. We find a statistically significant difference in the degree of cardio-respiratory synchronization during different sleep stages for both young and elderly subjects and a significant decline of synchronization with age. This is a first evidence of how sleep regulation and aging influence a key nonlinear mechanism of physiologic coupling as quantified by the degree of phase synchronization between the cardiac and respiratory systems, which is of importance to develop adequate modeling approaches.

The Effects of Sleep Continuity Disruption on Positive Mood and Sleep Architecture in Healthy Adults

PubMed Central

Finan, Patrick H.; Quartana, Phillip J.; Smith, Michael T.

2015-01-01

Objective: The purpose of this study was to test an experimental model of the effects of sleep continuity disturbance on sleep architecture and positive mood in order to better understand the mechanisms linking insomnia and depression. Design: Participants were randomized to receive 3 consecutive nights of sleep continuity disruption via forced nocturnal awakenings (FA, n = 21), or one of two control conditions: restricted sleep opportunity (RSO, n = 17) or uninterrupted sleep (US, n = 24). Setting: The study was set in an inpatient clinical research suite. Participants: Healthy, good-sleeping men and women were included. Measurement and Results: Polysomnography was used to measure sleep architecture, and mood was assessed via self-report each day. Compared to restricted sleep opportunity controls, forced awakenings subjects had significantly less slow wave sleep (P < 0.05) after the first night of sleep deprivation, and significantly lower positive mood (P < 0.05) after the second night of sleep deprivation. The differential change in slow wave sleep statistically mediated the observed group differences in positive mood (P = 0.002). Conclusions: To our knowledge, this is the first human experimental study to demonstrate that, despite comparable reductions in total sleep time, partial sleep loss from sleep continuity disruption is more detrimental to positive mood than partial sleep loss from delaying bedtime, even when controlling for concomitant increases in negative mood. With these findings, we provide temporal evidence in support of a putative biologic mechanism (slow wave sleep deficit) that could help explain the strong comorbidity between insomnia and depression. Citation: Finan PH, Quartana PJ, Smith MT. The effects of sleep continuity disruption on positive mood and sleep architecture in healthy adults. SLEEP 2015;38(11):1735–1742. PMID:26085289

National data showed that delayed sleep in six-year-old children was associated with excessive use of electronic devices at 12 years.

PubMed

Kato, Tsuguhiko; Yorifuji, Takashi; Yamakawa, Michiyo; Inoue, Sachiko

2018-01-31

Cross-sectional studies have shown associations between adolescent sleep problems and the use of electronic devices, such as mobile phones, but longitudinal studies remain scarce. We explored any association between delayed bedtimes at six years old and the excessive use of electronic devices at 12 years of age. Texting was a prime focus. We analysed 9607 adolescents who owned mobile phones in 2013 using the Japanese Longitudinal Survey of Newborns in the 21st Century, which started in 2001. The outcomes were daily excessive use of a mobile phone, television (TV) and video games. Delayed bedtime at the age of six years was associated with excessive texting at weekends. The adjusted odds ratios and 95% confidence intervals obtained from logistic regression analyses were 1.88 (1.14-3.10) for the 10-11 pm group and 1.98 (1.08-3.63) for the after 11 pm group, compared with the before 9 pm group. Later bedtimes were also associated with increased risks of excessive TV viewing and video game use. Our study indicated that six-year-olds who regularly stayed up late at night used electronic devices more frequently, or for longer, at the age of 12. Parents need to be more aware of links between sleep issues and electronic devices. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

The Effects of Changing the Phase and Duration of Sleep

ERIC Educational Resources Information Center

Taub, John M.; Berger, Ralph J.

1976-01-01

The purpose of the present experiment was to compare the effects on performance and mood of reduced and extended sleep with those following temporal shifts of sleep in a single group of subjects who characteristically sleep 9.5-10.5 hours per night. (Author)

Effect of timed bright light treatment for rest-activity disruption in institutionalized patients with Alzheimer's disease.

PubMed

Dowling, Glenna A; Mastick, Judy; Hubbard, Erin M; Luxenberg, Jay S; Burr, Robert L

2005-08-01

Disturbances in rest-activity rhythm are prominent and disabling symptoms in Alzheimer's disease (AD). Nighttime sleep is severely fragmented and daytime activity is disrupted by multiple napping episodes. In most institutional environments, light levels are very low and may not be sufficient to entrain the circadian clock to the 24-hour day. The purpose of this randomized clinical trial was to test the effectiveness of timed bright light therapy in reducing rest-activity (circadian) disruption in institutionalized patients with AD. The experimental groups received either morning (9.30-10.30 am) or afternoon (3.30-4.30 pm) bright light exposure ( > or = 2500 lux in gaze direction) Monday through Friday for 10 weeks. The control group received usual indoor light (150-200 lux). Nighttime sleep, daytime wake, and rest-activity parameters were determined by actigraphy. Repeated measures analysis of variance was employed to test the primary study hypotheses. Seventy institutionalized subjects with AD (mean age 84) completed the study. No significant differences in actigraphy-based measures of nighttime sleep or daytime wake were found between groups. Subjects in either experimental light condition evidenced a significantly (p < 0.01) more stable rest-activity rhythm acrophase over the 10-week treatment period compared to the control subjects whose rhythm phase delayed by over two hours. One hour of bright light, administered to subjects with AD either in the morning or afternoon, did not improve nighttime sleep or daytime wake compared to a control group of similar subjects. However, exposure to one-hour of bright light in either the morning or afternoon may provide sufficient additional input to the circadian pacemaker to facilitate entrainment to the 24-hour day. (c) 2005 John Wiley & Sons, Ltd.

Effect of timed bright light treatment for rest-activity disruption in institutionalized patients with Alzheimer’s disease

PubMed Central

Dowling, Glenna A.; Mastick, Judy; Hubbard, Erin M.; Luxenberg, Jay S.; Burr, Robert L.

2008-01-01

SUMMARY Background Disturbances in rest-activity rhythm are prominent and disabling symptoms in Alzheimer’s disease (AD). Nighttime sleep is severely fragmented and daytime activity is disrupted by multiple napping episodes. In most institutional environments, light levels are very low and may not be sufficient to entrain the circadian clock to the 24-hour day. Method The purpose of this randomized clinical trial was to test the effectiveness of timed bright light therapy in reducing rest-activity (circadian) disruption in institutionalized patients with AD. The experimental groups received either morning (9.30–10.30 am) or afternoon (3.30–4.30 pm) bright light exposure (≥ 2500 lux in gaze direction) Monday through Friday for 10 weeks. The control group received usual indoor light (150–200 lux). Nighttime sleep, daytime wake, and rest-activity parameters were determined by actigraphy. Repeated measures analysis of variance was employed to test the primary study hypotheses. Results Seventy institutionalized subjects with AD (mean age 84) completed the study. No significant differences in actigraphy-based measures of nighttime sleep or daytime wake were found between groups. Subjects in either experimental light condition evidenced a significantly (p < 0.01) more stable rest-activity rhythm acrophase over the 10-week treatment period compared to the control subjects whose rhythm phase delayed by over two hours. Conclusions One hour of bright light, administered to subjects with AD either in the morning or afternoon, did not improve nighttime sleep or daytime wake compared to a control group of similar subjects. However, exposure to one-hour of bright light in either the morning or afternoon may provide sufficient additional input to the circadian pacemaker to facilitate entrainment to the 24-hour day. PMID:16035127

Association between lunar phase and sleep characteristics.

PubMed

Turányi, Csilla Zita; Rónai, Katalin Zsuzsanna; Zoller, Rezső; Véber, Orsolya; Czira, Mária Eszter; Újszászi, Ákos; László, Gergely; Szentkirályi, András; Dunai, Andrea; Lindner, Anett; Szőcs, Julianna Luca; Becze, Ádám; Kelemen, Andrea; Lendvai, Zsófia; Molnar, Miklos Z; Mucsi, István; Novák, Márta

2014-11-01

Popular belief holds that the lunar cycle affects human physiology, behavior, and health, including sleep. To date, only a few and conflicting analyses have been published about the association between lunar phases and sleep. Our aim was to analyze the relationship between lunar phases and sleep characteristics. In this retrospective, cross-sectional analysis, data from 319 patients who had been referred for sleep study were included. Individuals with apnea-hypopnea index ≥ 15/h were excluded. Socio-demographic parameters were recorded. All participants underwent one-night standard polysomnography. Associations between lunar cycle (new moon, full moon and alternate moon) and sleep parameters were examined in unadjusted and adjusted models. Fifty-seven percent of patients were males. Mean age for men was 45 ± 14 years and 51 ± 12 years for women. In total, 224 persons had their sleep study done during alternate moon, 47 during full moon, and 48 during new moon. Full moon was associated with lower sleep efficiency [median (%) (IQR): new moon 82 (18), full moon 74 (19), alternate moon 82 (15); P < 0.001], less deep sleep [median (%) (IQR): new moon 9 (9), full moon 6 (4), alternate moon 11 (9); P < 0.001], and increased REM latency [median (min) (IQR): new moon 98 (74), full moon 137 (152), alternate moon 97 (76); P < 0.001], even after adjustment for several covariables. The results are consistent with a recent report and the widely held belief that sleep characteristics may be associated with the full moon. Copyright © 2014 Elsevier B.V. All rights reserved.

Characteristics of Sleep and Wakefulness inWild-Derived Inbred Mice

PubMed Central

HIYOSHI, Hideyuki; TERAO, Akira; OKAMATSU-OGURA, Yuko; KIMURA, Kazuhiro

2014-01-01

Genetic variations in the wild-derived inbred mouse strains are more diverse than that of classical laboratory inbred mouse strains, including C57BL/6J (B6). The sleep/wake and monoamine properties of six wild-derived inbred mouse strains (PGN2, NJL, BLG2, KJR, MSM, HMI) were characterized and compared with those of B6 mice. All examined mice were nocturnal and had a polyphasic sleep pattern with a “main sleep period” identified during the light period. However, there were three sleep/wake phenotypic differences between the wild-derived mouse strains and B6 strain. First, the amount of sleep during the dark phase was comparable with that of B6 mice. However, the amount of sleep during the light phase was more varied among strains, in particular, NJL and HMI had significantly less sleep compared with that of B6 mice. Second, PGN2, NJL, BLG2, and KJR mice showed a “highly awake period” (in which the hourly total sleep time was <10%) immediately after the onset of the dark period, which was not seen in B6 mice. Third, relative to that of B6 mice, PGN2 and KJR mice showed longer duration of wakefulness episodes during the 12-h dark phase. Differences in whole brain noradrenaline, dopamine, and 5-hydroxy-tryptamine contents between the wild-derived mouse strains and B6 strain were also found. These identified phenotypes might be potentially under strong genetic control. Hence, wild-derived inbred mice could be useful for identifying the genetic factors underlying the regulation of sleep and wakefulness. PMID:24770646

Brain gene expression during REM sleep depends on prior waking experience.

PubMed

Ribeiro, S; Goyal, V; Mello, C V; Pavlides, C

1999-01-01

In most mammalian species studied, two distinct and successive phases of sleep, slow wave (SW), and rapid eye movement (REM), can be recognized on the basis of their EEG profiles and associated behaviors. Both phases have been implicated in the offline sensorimotor processing of daytime events, but the molecular mechanisms remain elusive. We studied brain expression of the plasticity-associated immediate-early gene (IEG) zif-268 during SW and REM sleep in rats exposed to rich sensorimotor experience in the preceding waking period. Whereas nonexposed controls show generalized zif-268 down-regulation during SW and REM sleep, zif-268 is upregulated during REM sleep in the cerebral cortex and the hippocampus of exposed animals. We suggest that this phenomenon represents a window of increased neuronal plasticity during REM sleep that follows enriched waking experience.

Prediction of Vigilant Attention and Cognitive Performance Using Self-Reported Alertness, Circadian Phase, Hours since Awakening, and Accumulated Sleep Loss

PubMed Central

Bermudez, Eduardo B.; Klerman, Elizabeth B.; Czeisler, Charles A.; Cohen, Daniel A.; Wyatt, James K.; Phillips, Andrew J. K.

2016-01-01

Sleep restriction causes impaired cognitive performance that can result in adverse consequences in many occupational settings. Individuals may rely on self-perceived alertness to decide if they are able to adequately perform a task. It is therefore important to determine the relationship between an individual’s self-assessed alertness and their objective performance, and how this relationship depends on circadian phase, hours since awakening, and cumulative lost hours of sleep. Healthy young adults (aged 18–34) completed an inpatient schedule that included forced desynchrony of sleep/wake and circadian rhythms with twelve 42.85-hour “days” and either a 1:2 (n = 8) or 1:3.3 (n = 9) ratio of sleep-opportunity:enforced-wakefulness. We investigated whether subjective alertness (visual analog scale), circadian phase (melatonin), hours since awakening, and cumulative sleep loss could predict objective performance on the Psychomotor Vigilance Task (PVT), an Addition/Calculation Test (ADD) and the Digit Symbol Substitution Test (DSST). Mathematical models that allowed nonlinear interactions between explanatory variables were evaluated using the Akaike Information Criterion (AIC). Subjective alertness was the single best predictor of PVT, ADD, and DSST performance. Subjective alertness alone, however, was not an accurate predictor of PVT performance. The best AIC scores for PVT and DSST were achieved when all explanatory variables were included in the model. The best AIC score for ADD was achieved with circadian phase and subjective alertness variables. We conclude that subjective alertness alone is a weak predictor of objective vigilant or cognitive performance. Predictions can, however, be improved by knowing an individual’s circadian phase, current wake duration, and cumulative sleep loss. PMID:27019198

Preliminary randomized double-blind placebo-controlled trial of tryptophan combined with fluoxetine to treat major depressive disorder: antidepressant and hypnotic effects.

PubMed Central

Levitan, R D; Shen, J H; Jindal, R; Driver, H S; Kennedy, S H; Shapiro, C M

2000-01-01

OBJECTIVE: Because the initial phase of treatment of depression with a selective serotonin reuptake inhibitor is often complicated by a delayed onset of action of the antidepressant or severe insomnia or both, we investigated whether tryptophan, an amino acid with both antidepressant-augmenting and hypnotic effects, would benefit patients with depression at the beginning of treatment with fluoxetine. DESIGN: Randomized, double-blind, placebo-controlled trial. PATIENTS: Thirty individuals with major depressive disorder. INTERVENTIONS: Treatment over 8 weeks with 20 mg of fluoxetine per day and either tryptophan (2 to 4 g per day) or placebo. OUTCOME MEASURES: Mood was assessed using the 29-item Hamilton Depression Rating Scale (HDRS-29) and the Beck Depression Inventory (BDI). Laboratory sleep studies were done at baseline and after 4 and 8 weeks of treatment using standard procedures. RESULTS: During the first week of treatment, there was a significantly greater decrease in HDRS-29 depression scores, and a similar trend in BDI scores, in the tryptophan/fluoxetine group than in the placebo/fluoxetine group. No significant differences were noted at later time points. With respect to sleep measures, there was a significant group-by-time interaction for slow-wave sleep at week 4. Further analysis revealed a significant decrease in slow-wave sleep after 4 weeks of treatment in the placebo/fluoxetine group, but not in the tryptophan/fluoxetine group. No cases of serotonin syndrome occurred, and the combination was well tolerated, although the 4 g per day dosage of tryptophan produced daytime drowsiness. CONCLUSIONS: Combining 20 mg of fluoxetine with 2 g of tryptophan daily at the outset of treatment for major depressive disorder appears to be a safe protocol that may have both a rapid antidepressant effect and a protective effect on slow-wave sleep. Further large-scale studies are needed to confirm these initial findings. PMID:11022398

Sleep phenotypes in infants and toddlers with neurogenetic syndromes.

PubMed

Abel, Emily A; Tonnsen, Bridgette L

2017-10-01

Although sleep problems are well characterized in preschool- and school-age children with neurogenetic syndromes, little is known regarding the early emergence of these problems in infancy and toddlerhood. To inform syndrome-specific profiles and targets for intervention, we compared parent-reported sleep problems in infants and toddlers with Angelman syndrome (AS), Williams syndrome (WS), and Prader-Willi syndrome (PWS) with patterns observed among same-aged typically developing (TD) controls. Mothers of 80 children (18 AS, 19 WS, 19 PWS, and 24 TD) completed the Brief Infant Sleep Questionnaire. Primary dependent variables included (1) sleep onset latency, (2) total sleep duration, (3) daytime and nighttime sleep duration, and (4) sleep problem severity, as measured by both maternal impression and National Sleep Foundation guidelines. Sleep problems are relatively common in children with neurogenetic syndromes, with 41% of mothers reporting problematic sleep and 29% of children exhibiting abnormal sleep durations as per national guidelines. Across genetic subgroups, problems are most severe in children with AS and WS, particularly in relation to nighttime sleep duration. Although atypical sleep is characteristically reported in each syndrome later in development, infants and toddlers with PWS exhibited largely typical patterns, potentially indicating delayed onset of sleep problems in concordance with other medical features of PWS. Our findings suggest that sleep problems in neurogenetic syndromes emerge as early as infancy and toddlerhood, with variable profiles across genetic subgroups. This work underscores the importance of early sleep screenings as part of routine medical care of neurosyndromic populations and the need for targeted, syndrome-sensitive treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Managing sleep and wakefulness in a 24-hour world.

PubMed

Coveney, Catherine M

2014-01-01

This article contributes to literature on the sociology of sleep by exploring the sleeping practices and subjective sleep experiences of two social groups: shift workers and students. It draws on data, collected in the UK from 25 semi-structured interviews, to discuss the complex ways in which working patterns and social activities impact upon experiences and expectations of sleep in our wired awake world. The data show that, typically, sleep is valued and considered to be important for health, general wellbeing, appearance and physical and cognitive functioning. However, sleep time is often cut back on in favour of work demands and social activities. While shift workers described their efforts to fit in an adequate amount of sleep per 24-hour period, for students, the adoption of a flexible sleep routine was thought to be favourable for maintaining a work-social life balance. Collectively, respondents reported using a wide range of strategies, techniques, technologies and practices to encourage, overcome or delay sleep(iness) and boost, promote or enhance wakefulness/alertness at socially desirable times. The analysis demonstrates how social context impacts not only on how we come to think about sleep and understand it, but also how we manage or self-regulate our sleeping patterns. © 2013 The Author. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

School-Based Sleep Education Programs for Short Sleep Duration in Adolescents: A Systematic Review and Meta-Analysis.

PubMed

Chung, Ka-Fai; Chan, Man-Sum; Lam, Ying-Yin; Lai, Cindy Sin-Yee; Yeung, Wing-Fai

2017-06-01

Insufficient sleep among students is a major school health problem. School-based sleep education programs tailored to reach large number of students may be one of the solutions. A systematic review and meta-analysis was conducted to summarize the programs' effectiveness and current status. Electronic databases were searched up until May 2015. Randomized controlled trials of school-based sleep intervention among 10- to 19-year-old students with outcome on total sleep duration were included. Methodological quality of the studies was assessed using the Cochrane's risk of bias assessment. Seven studies were included, involving 1876 students receiving sleep education programs and 2483 attending classes-as-usual. Four weekly 50-minute sleep education classes were most commonly provided. Methodological quality was only moderate, with a high or an uncertain risk of bias in several domains. Compared to classes-as-usual, sleep education programs produced significantly longer weekday and weekend total sleep time and better mood among students at immediate post-treatment, but the improvements were not maintained at follow-up. Limited by the small number of studies and methodological limitations, the preliminary data showed that school-based sleep education programs produced short-term benefits. Future studies should explore integrating sleep education with delayed school start time or other more effective approaches. © 2017, American School Health Association.

Sleep Habits and Sleep Problems in Healthy Preschoolers.

PubMed

Murthy, C L Srinivasa; Bharti, Bhavneet; Malhi, Prahbhjot; Khadwal, Alka

2015-07-01

To describe the sleep patterns and problems in children aged between 12 and 36 mo of age. This cross sectional survey was collected over a span of 1 y in Advanced Pediatric Centre, PGIMER, Chandigarh and crèches of Chandigarh. Children in the age group of 12 to 36 mo were included in study. Children with chronic illness, developmental delay, seizure disorder and lack of consent were excluded. A total of 368 children were enrolled. Main outcome measures were sleep duration over 1 to 3 y of life; sleep behavior at onset, during and waking of sleep and parent reported sleep problems and their predictors. The average duration of sleep was 12.5 h (S.D = 1.9). The mean total sleep duration and mean day time sleep duration decreased, while mean night time sleep increased as the age advanced from 12 to 36 mo. Following were the frequency of sleep habits seen in the index study; bed time routine was seen only in 68(18.5 %), a regular bed time ritual was seen in 281(76.4 %), 329(89.4 %) children frequently required 0-20 min time to fall asleep, 11(3 %) parents used sleep inducing drugs. Night waking (1 to 3 times a night) was seen in 297(80.7 %) and its frequency declined with age. Parent reported sleep problems were seen in 12.8 % (47/368). Lack of co-sleeping and night waking were considered as strongest predictors of parent reported sleep problems. Toddlers' sleep duration, night waking behavior, and day time naps decrease as the age progress while night time sleep duration increases with age. Lack of co-sleeping and night waking are considered as strongest predictors of parent reported sleep problems.

Contribution of sleep to the repair of neuronal DNA double-strand breaks: evidence from flies and mice.

PubMed

Bellesi, Michele; Bushey, Daniel; Chini, Mattia; Tononi, Giulio; Cirelli, Chiara

2016-11-10

Exploration of a novel environment leads to neuronal DNA double-strand breaks (DSBs). These DSBs are generated by type 2 topoisomerase to relieve topological constrains that limit transcription of plasticity-related immediate early genes. If not promptly repaired, however, DSBs may lead to cell death. Since the induction of plasticity-related genes is higher in wake than in sleep, we asked whether it is specifically wake associated with synaptic plasticity that leads to DSBs, and whether sleep provides any selective advantage over wake in their repair. In flies and mice, we find that enriched wake, more than simply time spent awake, induces DSBs, and their repair in mice is delayed or prevented by subsequent wake. In both species the repair of irradiation-induced neuronal DSBs is also quicker during sleep, and mouse genes mediating the response to DNA damage are upregulated in sleep. Thus, sleep facilitates the repair of neuronal DSBs.

Circadian rhythms and sleep patterns in urban Greek couples.

PubMed

Lee, Kathryn A; Beyene, Yewoubdar; Paparrigopoulos, Thomas J; Dikeos, Dimitris G; Soldatos, Constantin R

2007-07-01

A convenience sample of 14 adults (seven couples) who intentionally nap regularly was recruited to describe circadian rhythms and sleep patterns in a culture in which afternoon naps are routine. Participants wore a wrist actigraph for 48 hr during May to obtain two peaks and troughs of activity data. Peak activity, estimated by cosinor analysis (acrophase), occurred at 1542 hours for men and at 1600 hours for women. Compared to their male partners, women had a later acrophase and a significantly stronger 24-hr rhythm, despite similar nap and nighttime sleep schedules. Men had more awakenings during the night and slightly shorter naps than did women. For the 24-hr period, men averaged 6.8 +/- 1.0 hr of sleep and women averaged 7.4 +/- 1.1 hr. Results indicate that Greek adults delay sleep onset at night and awaken early in the morning. Among this small group, naps are an accepted cultural behavior.

Effects of Sport-Specific Training Intensity on Sleep Patterns and Psychomotor Performance in Adolescent Athletes.

PubMed

Suppiah, Haresh T; Low, Chee Yong; Chia, Michael

2016-11-01

Adolescent student-athletes face time constraints due to athletic and scholastic commitments, resulting in habitually shortened nocturnal sleep durations. However, there is a dearth of research on the effects of sleep debt on student-athlete performance. The study aimed to (i) examine the habitual sleep patterns (actigraphy) of high-level student-athletes during a week of training and academic activities, (ii) ascertain the effects of habitual sleep durations experienced by high-level student-athletes on psychomotor performance, and (iii) examine the impact of sport training intensities on the sleep patterns of high-level student-athletes that participate in low and high intensity sports. Sleep patterns of 29 high-level student-athletes (14.7 ± 1.3 yrs) were monitored over 7 days. A psychomotor vigilance task was administered on weekdays to ascertain the effects of habitual sleep durations. Weekend total sleep time was longer than weekdays along with a delay in bedtime, and waketimes. Psychomotor vigilance reaction times on Monday were faster than on Thursday and Friday, with reaction times on Tuesday also faster than on Friday. False starts and lapses were greater on Friday compared with Monday. There was a negative impact of sleep debt on student-athletes' psychomotor performance.

Effects of intrauterine growth restriction on sleep and the cardiovascular system: The use of melatonin as a potential therapy?

PubMed

Yiallourou, Stephanie R; Wallace, Euan M; Miller, Suzanne L; Horne, Rosemary S C

2016-04-01

Intrauterine growth restriction (IUGR) complicates 5-10% of pregnancies and is associated with increased risk of preterm birth, mortality and neurodevelopmental delay. The development of sleep and cardiovascular control are closely coupled and IUGR is known to alter this development. In the long-term, IUGR is associated with altered sleep and an increased risk of hypertension in adulthood. Melatonin plays an important role in the sleep-wake cycle. Experimental animal studies have shown that melatonin therapy has neuroprotective and cardioprotective effects in the IUGR fetus. Consequently, clinical trials are currently underway to assess the short and long term effects of antenatal melatonin therapy in IUGR pregnancies. Given melatonin's role in sleep regulation, this hormone could affect the developing infants' sleep-wake cycle and cardiovascular function after birth. In this review, we will 1) examine the role of melatonin as a therapy for IUGR pregnancies and the potential implications on sleep and the cardiovascular system; 2) examine the development of sleep-wake cycle in fetal and neonatal life; 3) discuss the development of cardiovascular control during sleep; 4) discuss the effect of IUGR on sleep and the cardiovascular system and 5) discuss the future implications of melatonin therapy in IUGR pregnancies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Consolidating the effects of waking and sleep on motor-sequence learning.

PubMed

Brawn, Timothy P; Fenn, Kimberly M; Nusbaum, Howard C; Margoliash, Daniel

2010-10-20

Sleep is widely believed to play a critical role in memory consolidation. Sleep-dependent consolidation has been studied extensively in humans using an explicit motor-sequence learning paradigm. In this task, performance has been reported to remain stable across wakefulness and improve significantly after sleep, making motor-sequence learning the definitive example of sleep-dependent enhancement. Recent work, however, has shown that enhancement disappears when the task is modified to reduce task-related inhibition that develops over a training session, thus questioning whether sleep actively consolidates motor learning. Here we use the same motor-sequence task to demonstrate sleep-dependent consolidation for motor-sequence learning and explain the discrepancies in results across studies. We show that when training begins in the morning, motor-sequence performance deteriorates across wakefulness and recovers after sleep, whereas performance remains stable across both sleep and subsequent waking with evening training. This pattern of results challenges an influential model of memory consolidation defined by a time-dependent stabilization phase and a sleep-dependent enhancement phase. Moreover, the present results support a new account of the behavioral effects of waking and sleep on explicit motor-sequence learning that is consistent across a wide range of tasks. These observations indicate that current theories of memory consolidation that have been formulated to explain sleep-dependent performance enhancements are insufficient to explain the range of behavioral changes associated with sleep.

Flight Crew Sleep in Long-Haul Aircraft Bunk Facilities: Survey Results

NASA Technical Reports Server (NTRS)

Rosekind, Mark R.; Miller, Donna L.; Gregory, Kevin B.; Dinges, David F.; Shafto, Michael G. (Technical Monitor)

1995-01-01

Modem long-haul aircraft can fly up to 16 continuous hours and provide a 24-hour, global capability. Extra (augmented) flight crew are available on long flights to allow planned rest periods, on a rotating basis, away from the flight deck in onboard crew rest facilities (2 bunks). A NASA/FAA study is under-way to examine the quantity and quality of sleep obtained in long-haul aircraft bunks and the factors that promote or interfere with that sleep. The first phase of the study involved a retrospective survey, followed by a second phase field study to collect standard polysomnographic data during inflight bunk sleep periods. A summary of the Phase I survey results are reported here. A multi-part 54-question retrospective survey was completed by 1,404 flight crew (37% return rate) at three different major US air carriers flying B747-100, 200, 400, and MD- 11 long-haul aircraft. The questions examined demographics, quantity and quality of sleep at home and in onboard bunks, factors that promote or interfere with sleep, and effects on subsequent performance and alertness. Flight crew reported a mean bunk sleep latency of 39.4 mins (SD=28.3 mins) (n=1,276) and a mean total sleep time of 2.2 hrs (SD=1.3 hrs) (n=603). (Different flight lengths could affect overall time available for sleep.) Crew rated 25 factors for their interference or promotion of bunk sleep. Figure I portrays the average ratings for each factor across all three carriers. A principal components analysis of the 25 factors revealed three areas that promoted bunk sleep: physiological (e.g., readiness for sleep), physical environment (e.g., bunk size, privacy), and personal comfort (e.g., blankets, pillows). Five areas were identified that interfered with sleep: environmental disturbance (e.g., background noise, turbulence), luminosity (e.g., lighting), personal disturbances (e.g., bathroom trips, random thoughts), environmental discomfort (e.g., low humidity, cold), and interpersonal disturbances (e.g., bunk partner).

Orexin OX2 Receptor Antagonists as Sleep Aids.

PubMed

Jacobson, Laura H; Chen, Sui; Mir, Sanjida; Hoyer, Daniel

The discovery of the orexin system represents the single major progress in the sleep field of the last three to four decades. The two orexin peptides and their two receptors play a major role in arousal and sleep/wake cycles. Defects in the orexin system lead to narcolepsy with cataplexy in humans and dogs and can be experimentally reproduced in rodents. At least six orexin receptor antagonists have reached Phase II or Phase III clinical trials in insomnia, five of which are dual orexin receptor antagonists (DORAs) that target both OX 1 and OX 2 receptors (OX 2 Rs). All clinically tested DORAs induce and maintain sleep: suvorexant, recently registered in the USA and Japan for insomnia, represents the first hypnotic principle that acts in a completely different manner from the current standard medications. It is clear, however, that in the clinic, all DORAs promote sleep primarily by increasing rapid eye movement (REM) and are almost devoid of effects on slow-wave (SWS) sleep. At present, there is no consensus on whether the sole promotion of REM sleep has a negative impact in patients suffering from insomnia. However, sleep onset REM (SOREM), which has been documented with DORAs, is clearly an undesirable effect, especially for narcoleptic patients and also in fragile populations (e.g. elderly patients) where REM-associated loss of muscle tone may promote an elevated risk of falls. Debate thus remains as to the ideal orexin agent to achieve a balanced increase in REM and non-rapid eye movement (NREM) sleep. Here, we review the evidence that an OX 2 R antagonist should be at least equivalent, or perhaps superior, to a DORA for the treatment of insomnia. An OX 2 R antagonist may produce more balanced sleep than a DORA. Rodent sleep experiments show that the OX 2 R is the primary target of orexin receptor antagonists in sleep modulation. Furthermore, an OX 2 R antagonist should, in theory, have a lower narcoleptic/cataplexic potential. In the clinic, the situation remains equivocal, since OX 2 R antagonists are in early stages: MK-1064 has completed Phase I, and MIN202 is currently in clinical Phase II/III trials. However, data from insomnia patients have not yet been released. Promotional material suggests that balanced sleep is indeed induced by MIN-202, whereas in volunteers MK-1064 has been reported to act similarly to DORAs.

Treatment of GABA from Fermented Rice Germ Ameliorates Caffeine-Induced Sleep Disturbance in Mice

PubMed Central

Mabunga, Darine Froy N.; Gonzales, Edson Luck T.; Kim, Hee Jin; Choung, Se Young

2015-01-01

γ-Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is involved in sleep physiology. Caffeine is widely used psychoactive substance known to induce wakefulness and insomnia to its consumers. This study was performed to examine whether GABA extracts from fermented rice germ ameliorates caffeine-induced sleep disturbance in mice, without affecting spontaneous locomotor activity and motor coordination. Indeed, caffeine (10 mg/kg, i.p.) delayed sleep onset and reduced sleep duration of mice. Conversely, rice germ ferment extracts-GABA treatment (10, 30, or 100 mg/kg, p.o.), especially at 100 mg/kg, normalized the sleep disturbance induced by caffeine. In locomotor tests, rice germ ferment extracts-GABA slightly but not significantly reduced the caffeine-induced increase in locomotor activity without affecting motor coordination. Additionally, rice germ ferment extracts-GABA per se did not affect the spontaneous locomotor activity and motor coordination of mice. In conclusion, rice germ ferment extracts-GABA supplementation can counter the sleep disturbance induced by caffeine, without affecting the general locomotor activities of mice. PMID:25995826

Two- and 4-hour bright-light exposures differentially effect sleepiness and performance the subsequent night.

PubMed

Thessing, V C; Anch, A M; Muehlbach, M J; Schweitzer, P K; Walsh, J K

1994-03-01

The effect of two durations of bright light upon sleepiness and performance during typical night shift hours was assessed. Thirty normal, healthy young adults participated in a 2-night protocol. On the 1st night subjects were exposed to bright or dim light beginning at 2400 hours, under one of the following three conditions: bright light for 4 hours, dim light for 2 hours followed by bright light for 2 hours or dim light for 4 hours. Following light exposure, subjects remained awake until 0800 hours in a dimly lit room and slept in the laboratory between 0800 and 1600 hours, during which time sleep was estimated with actigraphy. Throughout the 2nd night, the multiple sleep latency test (MSLT), simulated assembly line task (SALT) performance, and subjective sleepiness were recorded. The single, 4-hour exposure to bright light was found to significantly increase MSLT scores and improve SALT performance during the early morning hours on the night following bright-light exposure. No significant effects were noted with a 2-hour exposure. The most likely explanation for these findings is a phase delay in the circadian rhythm of sleepiness-alertness.

"Sleep is not tangible" or what the Hebrew tradition has to say about sleep.

PubMed

Ancoli-Israel, S

2001-01-01

Much of what is known about sleep disorders has been uncovered in the last forty years. As scientists, we consider these discoveries to be landmarks. Yet there is a tremendous amount of information written about sleep in the Bible and its commentaries. Sleep, and even sleep disorders, are referred to in many instances and can be directly interpreted by what we know today. Our forefathers and foremothers generally viewed sleep as both pleasant and necessary and were aware that sleep was not one continuous stage. They referred to the function of sleep as being restorative. They deplored sleep deprivation, believing that it impaired life. They felt that excessive sleepiness was harmful. They understood that insomnia could be caused by stress and anxiety and by excessive alcohol, and that physical activity (exercise) and drinking milk could improve sleep. They suggested cures for insomnia, including some of the ideas included in today's sleep hygiene rules. They understood that there was a rhythm or timing to sleep. They even understood that it is easier to delay the circadian rhythm that to advance it. Although naps are not recommended, they sometimes took naps in the afternoon, but suggested just how long that nap should last-about one-half hour. And they knew that with age, although sleep is advanced, healthy elderly do not have difficulty sleeping. Although we think we have discovered many new features about sleep disorders, much of what we know today was suggested thousands of years ago and documented in the Bible and the Talmud.

A Rodent Model of Night-Shift Work Induces Short-Term and Enduring Sleep and Electroencephalographic Disturbances.

PubMed

Grønli, Janne; Meerlo, Peter; Pedersen, Torhild T; Pallesen, Ståle; Skrede, Silje; Marti, Andrea R; Wisor, Jonathan P; Murison, Robert; Henriksen, Tone E G; Rempe, Michael J; Mrdalj, Jelena

2017-02-01

Millions of people worldwide are working at times that overlap with the normal time for sleep. Sleep problems related to the work schedule may mediate the well-established relationship between shift work and increased risk for disease, occupational errors and accidents. Yet, our understanding of causality and the underlying mechanisms that explain this relationship is limited. We aimed to assess the consequences of night-shift work for sleep and to examine whether night-shift work-induced sleep disturbances may yield electrophysiological markers of impaired maintenance of the waking brain state. An experimental model developed in rats simulated a 4-day protocol of night-work in humans. Two groups of rats underwent 8-h sessions of enforced ambulation, either at the circadian time when the animal was physiologically primed for wakefulness (active-workers, mimicking day-shift) or for sleep (rest-workers, mimicking night-shift). The 4-day rest-work schedule induced a pronounced redistribution of sleep to the endogenous active phase. Rest-work also led to higher electroencephalogram (EEG) slow-wave (1-4 Hz) energy in quiet wakefulness during work-sessions, suggesting a degraded waking state. After the daily work-sessions, being in their endogenous active phase, rest-workers slept less and had higher gamma (80-90 Hz) activity during wake than active-workers. Finally, rest-work induced an enduring shift in the main sleep period and attenuated the accumulation of slow-wave energy during NREM sleep. A comparison of recovery data from 12:12 LD and constant dark conditions suggests that reduced time in NREM sleep throughout the recorded 7-day recovery phase induced by rest-work may be modulated by circadian factors. Our data in rats show that enforced night-work-like activity during the normal resting phase has pronounced acute and persistent effects on sleep and waking behavior. The study also underscores the potential importance of animal models for future studies on the health consequences of night-shift work and the mechanisms underlying increased risk for diseases.

The Relative Contributions of the Homeostatic and Circadian Processes to Sleep Regulation under Conditions of Severe Sleep Restriction

PubMed Central

Paech, Gemma M.; Ferguson, Sally A.; Sargent, Charli; Kennaway, David J.; Roach, Gregory D.

2012-01-01

Study Objectives: To investigate the relative contributions of the homeostatic and circadian processes on sleep regulation under conditions of severe sleep restriction. Design: The 13-day laboratory based study consisted of 3 × 24-h baseline days (8 h sleep opportunity, 16 h wake) followed by 7 × 28-h forced desynchrony days (4.7 h sleep opportunity, 23.3 h wake). Setting: The study was conducted in a time isolation unit at the Centre for Sleep Research, University of South Australia. Participants: Fourteen healthy, nonsmoking males, aged 21.8 ± 3.8 (mean ± SD) years participated in the study. Interventions: N/A Measurements: Sleep was measured using standard polysomnography. Core body temperature (CBT) was recorded continuously using a rectal thermistor. Each epoch of sleep was assigned a circadian phase based on the CBT data (6 × 60-degree bins) and an elapsed time into sleep episode (2 × 140-min intervals). Results: The percentage of SWS decreased with elapsed time into the sleep episode. However, no change in the percentage of REM sleep was observed with sleep progression. Whilst there was a circadian modulation of REM sleep, the amplitude of the circadian variation was smaller than expected. Sleep efficiency remained high throughout the sleep episode and across all circadian phases. Conclusions: Previous forced desynchrony studies have demonstrated a strong circadian influence on sleep, in the absence of sleep restriction. The current study suggests that in the presence of high homeostatic pressure, the circadian modulation of sleep, in particular sleep efficiency and to a lesser extent, REM sleep, are reduced. Citation: Paech GM; Ferguson SA; Sargent C; Kennaway DJ; Roach GD. The relative contributions of the homeostatic and circadian processes to sleep regulation under conditions of severe sleep restriction. SLEEP 2012;35(7):941-948. PMID:22754040

Coordinated infraslow neural and cardiac oscillations mark fragility and offline periods in mammalian sleep

PubMed Central

Lecci, Sandro; Fernandez, Laura M. J.; Weber, Frederik D.; Cardis, Romain; Chatton, Jean-Yves; Born, Jan; Lüthi, Anita

2017-01-01

Rodents sleep in bouts lasting minutes; humans sleep for hours. What are the universal needs served by sleep given such variability? In sleeping mice and humans, through monitoring neural and cardiac activity (combined with assessment of arousability and overnight memory consolidation, respectively), we find a previously unrecognized hallmark of sleep that balances two fundamental yet opposing needs: to maintain sensory reactivity to the environment while promoting recovery and memory consolidation. Coordinated 0.02-Hz oscillations of the sleep spindle band, hippocampal ripple activity, and heart rate sequentially divide non–rapid eye movement (non-REM) sleep into offline phases and phases of high susceptibility to external stimulation. A noise stimulus chosen such that sleeping mice woke up or slept through at comparable rates revealed that offline periods correspond to raising, whereas fragility periods correspond to declining portions of the 0.02-Hz oscillation in spindle activity. Oscillations were present throughout non-REM sleep in mice, yet confined to light non-REM sleep (stage 2) in humans. In both species, the 0.02-Hz oscillation predominated over posterior cortex. The strength of the 0.02-Hz oscillation predicted superior memory recall after sleep in a declarative memory task in humans. These oscillations point to a conserved function of mammalian non-REM sleep that cycles between environmental alertness and internal memory processing in 20- to 25-s intervals. Perturbed 0.02-Hz oscillations may cause memory impairment and ill-timed arousals in sleep disorders. PMID:28246641

Procedural performance following sleep deprivation remains impaired despite extended practice and an afternoon nap

PubMed Central

Kurniawan, Irma Triasih; Cousins, James Nicholas; Chong, Pearlynne L. H.; Chee, Michael W. L.

2016-01-01

The negative impact of sleep loss on procedural memory is well established, yet it remains unclear how extended practice opportunities or daytime naps can modulate the effect of a night of sleep deprivation. Here, participants underwent three training and test conditions on a sequential finger tapping task (SFTT) separated by at least one week. In the first condition they were trained in the evening followed by a night of sleep. Two further conditions took place where evening training was followed by a night of total sleep deprivation (TSD). One of the TSD conditions included a one-hour nap opportunity (15:00). Compared to the condition in which sleep was permitted, a night of TSD resulted in poorer performance across 4 practices the following day (10:00–19:00). The deleterious effect of a single night of TSD on procedural performance, was neither clearly alleviated by an afternoon nap nor by multiple practice opportunities. Interestingly, significant gains in performance were observed in all conditions after a one-week delay. Recovery sleep on subsequent nights thus appeared to nullify the effect of a single night of sleep deprivation, underscoring the importance of offline consolidation on the acquisition of procedural skill. PMID:27782172

[The ultradian rhythm of sleep: diverse relations with pituitary and adrenal hormones].

PubMed

Brandenberger, G

2003-11-01

We evaluated the relationship between the ultradian rhythm of sleep and the secretory episodes of pituitary-adrenal hormones. Prolactin (PRL) and TSH exhibited opposite phase relationships with delta waves, PRL increasing and TSH decreasing when delta waves developed. Delta waves never increased together with an increase in cortisol secretion. They oscillated independently from each other throughout the 24 hour period, but when they were present at the same time, they oscillated in opposing phases. Concerning growth hormone (GH), its major peak which occurred shortly after sleep onset in association with the first slow wave sleep episode was blunted during sleep deprivation. However, this blunting was compensated during the day, so that the amount of GH secreted during a 24-hr period was similar whether or not a person had slept during the night. The physiological significance and the clinical implications of the various relationships of the endocrine systems with sleep are poorly known.

RGS Proteins and Gαi2 Modulate Sleep, Wakefulness, and Disruption of Sleep/ Wake States after Isoflurane and Sevoflurane Anesthesia.

PubMed

Zhang, Hao; Wheat, Heather; Wang, Peter; Jiang, Sha; Baghdoyan, Helen A; Neubig, Richard R; Shi, X Y; Lydic, Ralph

2016-02-01

This study tested the hypothesis that Regulators of G protein Signaling (RGS) proteins contribute to the regulation of wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep, and to sleep disruption caused by volatile anesthetics. The three groups used in this study included wild-type (WT; n = 7) mice and knock-in mice that were heterozygous (+/GS; n = 7) or homozygous (GS/GS; n = 7) for an RGS-insensitive allele that causes prolonged Gαi2 signaling. Mice were implanted with electrodes for recording sleep and conditioned for 1 week or more to sleep in the laboratory. Using within and between groups designs, 24-h recordings of wakefulness, NREM sleep, and REM sleep were compared across three interventions: (1) baseline (control) and after 3 h of being anesthetized with (2) isoflurane or (3) sevoflurane. Baseline recordings during the light phase revealed that relative to WT mice, homozygous RGS-insensitive (GS/GS) mice exhibit significantly increased wakefulness and decreased NREM and REM sleep. During the dark phase, these state-specific differences remained significant but reversed direction of change. After cessation of isoflurane and sevoflurane anesthesia there was a long-lasting and significant disruption of sleep and wakefulness. The durations of average episodes of wakefulness, NREM sleep, and REM sleep were significantly altered as a function of genotype and isoflurane and sevoflurane anesthesia. RGS proteins and Gαi2 play a significant role in regulating states of wakefulness, NREM sleep, and REM sleep. Genotype-specific differences demonstrate that RGS proteins modulate sleep disruption caused by isoflurane and sevoflurane anesthesia. The results also support the conclusion that isoflurane and sevoflurane anesthesia do not satisfy the homeostatic drive for sleep. © 2016 Associated Professional Sleep Societies, LLC.

The inappropriate occurrence of rapid eye movement sleep in narcolepsy is not due to a defect in homeostatic regulation of rapid eye movement sleep.

PubMed

Roman, Alexis; Meftah, Soraya; Arthaud, Sébastien; Luppi, Pierre-Hervé; Peyron, Christelle

2018-06-01

Narcolepsy type 1 is a disabling disorder with four primary symptoms: excessive-daytime-sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. The later three symptoms together with a short rapid eye movement (REM) sleep latency have suggested impairment in REM sleep homeostatic regulation with an enhanced propensity for (i.e. tendency to enter) REM sleep. To test this hypothesis, we challenged REM sleep homeostatic regulation in a recognized model of narcolepsy, the orexin knock-out (Orex-KO) mice and their wild-type (WT) littermates. We first performed 48 hr of REM sleep deprivation using the classic small-platforms-over-water method. We found that narcoleptic mice are similarly REM sleep deprived to WT mice. Although they had shorter sleep latency, Orex-KO mice recovered similarly to WT during the following 10 hr of recovery. Interestingly, Orex-KO mice also had cataplexy episodes immediately after REM sleep deprivation, anticipating REM sleep rebound, at a time of day when cataplexy does not occur in baseline condition. We then evaluated REM sleep propensity using our new automated method of deprivation that performs a specific and efficient REM sleep deprivation. We showed that REM sleep propensity is similar during light phase in Orex-KO and WT mice. However, during the dark phase, REM sleep propensity was not suppressed in Orex-KO mice when hypocretin/orexin neuropeptides are normally released. Altogether our data suggest that in addition to the well-known wake-promoting role of hypocretin/orexin, these neuropeptides would also suppress REM sleep. Therefore, hypocretin/orexin deficiency would facilitate the occurrence of REM sleep at any time of day in an opportunistic manner as seen in human narcolepsy.

Using the integrative model of behavioral prediction to identify promising message strategies to promote healthy sleep behavior among college students.

PubMed

Robbins, Rebecca; Niederdeppe, Jeff

2015-01-01

This research used the Integrative Model of Behavioral Prediction (IMBP) to examine cognitive predictors of intentions to engage in healthy sleep behavior among a population of college students. In doing so, we identify promising message strategies to increase healthy sleep behavior during college. In Phase 1, members of a small sample of undergraduates (n = 31) were asked to describe their beliefs about expected outcomes, norms, and perceived behavioral control associated with sleep on an open-ended questionnaire. We analyzed these qualitative responses to create a closed-ended survey about sleep-related attitudes, perceived norms, control beliefs, behavioral intentions, and behavior. In Phase 2, a larger sample of undergraduate students (n = 365) completed the survey. Attitudes and perceived behavioral control were the strongest predictors of both intentions to engage in sleep behavior and self-reported sleep behavior. Control beliefs associated with time management and stress also had substantial room to change, suggesting their potential as message strategies to better promote healthy sleep behavior in college. We conclude with a broader discussion of the study's implications for message design and intervention.

Sleep patterns and predictors of disturbed sleep in a large population of college students.

PubMed

Lund, Hannah G; Reider, Brian D; Whiting, Annie B; Prichard, J Roxanne

2010-02-01

To characterize sleep patterns and predictors of poor sleep quality in a large population of college students. This study extends the 2006 National Sleep Foundation examination of sleep in early adolescence by examining sleep in older adolescents. One thousand one hundred twenty-five students aged 17 to 24 years from an urban Midwestern university completed a cross-sectional online survey about sleep habits that included the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, the Horne-Ostberg Morningness-Eveningness Scale, the Profile of Mood States, the Subjective Units of Distress Scale, and questions about academic performance, physical health, and psychoactive drug use. Students reported disturbed sleep; over 60% were categorized as poor-quality sleepers by the PSQI, bedtimes and risetimes were delayed during weekends, and students reported frequently taking prescription, over the counter, and recreational psychoactive drugs to alter sleep/wakefulness. Students classified as poor-quality sleepers reported significantly more problems with physical and psychological health than did good-quality sleepers. Students overwhelmingly stated that emotional and academic stress negatively impacted sleep. Multiple regression analyses revealed that tension and stress accounted for 24% of the variance in the PSQI score, whereas exercise, alcohol and caffeine consumption, and consistency of sleep schedule were not significant predictors of sleep quality. These results demonstrate that insufficient sleep and irregular sleep-wake patterns, which have been extensively documented in younger adolescents, are also present at alarming levels in the college student population. Given the close relationships between sleep quality and physical and mental health, intervention programs for sleep disturbance in this population should be considered. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

Abnormal secretion of melatonin and cortisol in relation to sleep disturbances in children with Williams syndrome.

PubMed

Sniecinska-Cooper, Anna Maria; Iles, Ray Kruse; Butler, Stephen Andrew; Jones, Huw; Bayford, Richard; Dimitriou, Dagmara

2015-01-01

A high rate of sleep disturbances has been reported in individuals with Williams syndrome (WS) but the underlying aetiology has yet to be identified. Melatonin and cortisol levels display circadian rhythmicity and are known to affect and regulate sleep/wake patterns. The current study examined the levels of these two endocrine markers and explored a possible relationship with sleep patterns in children with WS. Twenty-five children with WS and 27 typically developing age- and gender-matched comparison children were recruited. Saliva was collected from each child at three time points: 4-6 pm, before natural bedtime, and after awakening. The levels of salivary melatonin and cortisol were analysed by specific enzyme-linked immunoassays. Sleep patterns were examined using actigraphy and the Children's Sleep Habit Questionnaire. The WS group had shallower drops in cortisol and less pronounced increase in melatonin at bedtime compared to the controls. Furthermore, they also had significantly higher levels of cortisol before bedtime. Increased bedtime cortisol and less pronounced rise in melatonin levels before sleep may play a role in the occurrence of sleep disturbances, such as delayed sleep onset, observed in children with WS. As both markers play a significant role in our circadian rhythm and sleep/wake cycle, it is necessary to examine sleep using multi-system analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Insufficient sleep in adolescents: causes and consequences.

PubMed

Owens, Judith A; Weiss, Miriam R

2017-08-01

Insufficient sleep poses an important and complicated set of health risks in the adolescent population. Not only is deficient sleep (defined as both sleep duration inadequate to meet sleep needs and sleep timing misaligned with the body's circadian rhythms) at epidemic levels in this population, but the contributing factors are both complex and numerous and there are a myriad of negative physical and mental health, safety and performance consequences. Causes of inadequate sleep identified in this population include internal biological processes such as the normal shift (delay) in circadian rhythm that occurs in association with puberty and a developmentally-based slowing of the "sleep drive", and external factors including extracurricular activities, excessive homework load, evening use of electronic media, caffeine intake and early school start times. Consequences range from inattentiveness, reduction in executive functioning and poor academic performance to increased risk of obesity and cardio-metabolic dysfunction, mood disturbances which include increased suicidal ideation, a higher risk of engaging in health risk behaviors such as alcohol and substance use, and increased rates of car crashes, occupational injuries and sports-related injuries. In response to these concerns, a number of promising measures have been proposed to reduce the burden of adolescent sleep loss, including healthy sleep education for students and families, and later school start times to allow adolescents to obtain sufficient and appropriately-timed sleep.