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Showing papers in "Journal of Sleep Research in 2017"


Journal ArticleDOI
TL;DR: In this article, a European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia.
Abstract: This European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia. The guideline is based on a systematic review of relevant meta-analyses published till June 2016. The target audience for this guideline includes all clinicians involved in the management of insomnia, and the target patient population includes adults with chronic insomnia disorder. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to grade the evidence and guide recommendations. The diagnostic procedure for insomnia, and its co-morbidities, should include a clinical interview consisting of a sleep history (sleep habits, sleep environment, work schedules, circadian factors), the use of sleep questionnaires and sleep diaries, questions about somatic and mental health, a physical examination and additional measures if indicated (i.e. blood tests, electrocardiogram, electroencephalogram; strong recommendation, moderate- to high-quality evidence). Polysomnography can be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders), in treatment-resistant insomnia, for professional at-risk populations and when substantial sleep state misperception is suspected (strong recommendation, high-quality evidence). Cognitive behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (strong recommendation, high-quality evidence). A pharmacological intervention can be offered if cognitive behavioural therapy for insomnia is not sufficiently effective or not available. Benzodiazepines, benzodiazepine receptor agonists and some antidepressants are effective in the short-term treatment of insomnia (≤4 weeks; weak recommendation, moderate-quality evidence). Antihistamines, antipsychotics, melatonin and phytotherapeutics are not recommended for insomnia treatment (strong to weak recommendations, low- to very-low-quality evidence). Light therapy and exercise need to be further evaluated to judge their usefulness in the treatment of insomnia (weak recommendation, low-quality evidence). Complementary and alternative treatments (e.g. homeopathy, acupuncture) are not recommended for insomnia treatment (weak recommendation, very-low-quality evidence).

1,076 citations


Journal ArticleDOI
TL;DR: Across both sleep conditions, use of cognitive reappraisal down‐regulated negative emotion effectively; however, sleep restriction did not impact upon adolescents’ ability to use this strategy, adding to a growing body of literature demonstrating the deleterious effects of sleep restriction on aspects of emotion.
Abstract: Summary Sleep loss is associated with affective disturbances and disorders; however, there is limited understanding of specific mechanisms underlying these links, especially in adolescence. The current study tested the effects of sleep restriction versus idealized sleep on adolescents’ emotional experience, reactivity and regulation (specifically cognitive reappraisal). Following 1 week of sleep monitoring, healthy adolescents (n = 42; ages 13–17 years) were randomized to 1 night of sleep restriction (4 h) or idealized sleep (9.5 h). The following day, adolescents provided self-reports of affect and anxiety and completed a laboratory-based task to assess: (1) emotional reactivity in response to positive, negative, and neutral images from the International Affective Picture System (IAPS); and (2) ability to use cognitive reappraisal to decrease negative emotional responses. Large effects were observed for the adverse impact of sleep restriction on positive affect and anxiety as well as a medium-sized effect for negative affect, compared to the idealized sleep condition. Subjective reactivity to positive and neutral images did not differ between the groups, but a moderate effect was detected for reactivity to negative images whereby sleep-restricted teens reported greater reactivity. Across both sleep conditions, use of cognitive reappraisal down-regulated negative emotion effectively; however, sleep restriction did not impact upon adolescents’ ability to use this strategy. These findings add to a growing body of literature demonstrating the deleterious effects of sleep restriction on aspects of emotion and highlight directions for future research in adolescents.

70 citations


Journal ArticleDOI
TL;DR: In this paper, the authors assessed night-to-night variability of obstructive sleep apnea to reassess the current practice, and found that the variability was higher in less severe OSA patients.
Abstract: Summary One night of a sleep study is the standard for diagnosis and exclusion of obstructive sleep apnea Single testing requires high sensitivity of the test method and a stable disease of interest to warrant a low rate of false-negative tests Obstructive sleep apnea is diagnosed and graded by conventional thresholds of apneas and hypopneas per hour of sleep, and treatment is usually initiated in the presence of symptoms The aim of this study was to assess night-to-night variability of obstructive sleep apnea to reassess the current practice Seventy-seven patients previously diagnosed with obstructive sleep apnea, randomised to continuous positive airway pressure withdrawal within four trials, performed nightly pulse-oximetry over 2 weeks while off continuous positive airway pressure The main outcome of interest was the coefficient of variation of the oxygen desaturation index marking night-to-night variability in obstructive sleep apnea Obstructive sleep apnea was categorised according to conventional thresholds using oxygen desaturation index (no obstructive sleep apnea: 30 per h) High night-to-night variability of obstructive sleep apnea was evidenced by a coefficient of variation of oxygen desaturation index of 311% (SD 165) Differences in oxygen desaturation index of >10 per h between nights were found in 844% and shifts in obstructive sleep apnea severity category in 779% of patients The probability of missing moderate obstructive sleep apnea was up to 60% Variability was higher in less severe obstructive sleep apnea Obstructive sleep apnea shows a considerable night-to-night variability Single-night diagnostic sleep studies are prone to miscategorise obstructive sleep apnea if arbitrary thresholds are used Thus, treatment decisions should be based less on the conventional derivatives from sleep studies, especially in patients with less severe obstructive sleep apnea Clinical trial registration: wwwcontrolled-trialscom (ISRCTN 93153804, ISRCTN 73047833) and wwwclinicaltrialsgov (NCT01332175 & NCT02050425)

68 citations


Journal ArticleDOI
TL;DR: A 24 h lighting system with enhanced daytime brightness and restricted nocturnal light exposure can improve some aspects of appraisal and objective sleep in hospital patients.
Abstract: Summary Irregular 24 h light/dark cycles with night-time light exposure and a low amplitude are disruptive for sleep, mood and circadian rhythms. Nevertheless such lighting conditions are quite common in medical care facilities. A controlled clinical trial among 196 cardiology ward patients (mean age 66.5 ± 13.1 years SD) investigated how a patient room lighting intervention affects sleep, appraisal and mood across hospitalization. Patients were either assigned to a standardly-lit room or to a room with an interventional lighting system offering a dynamic 24 h light/dark cycle with low nocturnal light exposure and 2 h of bright light (1750 lux) during daytime. Measures included wrist actigraphy and questionnaires assessing alertness, sleep quality, anxiety, depression and lighting appraisal. The median length of hospitalization was 5 days in both study arms. Subjective scores on sleep, alertness, anxiety and depression did not differ between arms. Lighting appraisal in intervention rooms was better as compared to standardly-lit rooms, both in patients (P < 0.001) and staff (P < 0.005). Actigraphic sleep duration of patients improved by 5.9 min (95% CI: 0.6–11.2; P = 0.03 intervention × time effect) per hospitalization day with interventional lighting instead of standard lighting. After 5 days of hospitalization, sleep duration in the lighting intervention rooms increased by 29 min, or a relative 7.3%, as compared to standardly-lit rooms. A 24 h lighting system with enhanced daytime brightness and restricted nocturnal light exposure can improve some aspects of appraisal and objective sleep in hospital patients. More clinical research is needed to establish the best lighting strategy to promote healing and wellbeing within healthcare settings.

67 citations


Journal ArticleDOI
TL;DR: It is revealed that sleep hours and sleep quality were associated with next‐day consequences of work‐to‐family conflict and time inadequacy, whereas psychosocial stressors as antecedents did not predict sleep hours or quality that night.
Abstract: Summary Sleep can serve as both cause and consequence of individuals’ everyday experiences. We built upon prior studies of the correlates of sleep, which have relied primarily on cross-sectional data, to examine the antecedents and consequences of sleep using a daily diary design. Specifically, we assessed the temporal sequence between nightly sleep and daily psychosocial stressors. Parents employed in a US information technology company (n = 102) completed eight consecutive daily diaries at both baseline and 1 year later. In telephone interviews each evening, participants reported on the previous night's sleep hours, sleep quality and sleep latency. They also reported daily work-to-family conflict and time inadequacy (i.e. perceptions of not having enough time) for their child and for themselves to engage in exercise. Multi-level models testing lagged and non-lagged effects simultaneously revealed that sleep hours and sleep quality were associated with next-day consequences of work-to-family conflict and time inadequacy, whereas psychosocial stressors as antecedents did not predict sleep hours or quality that night. For sleep latency, the opposite temporal order emerged: on days with more work-to-family conflict or time inadequacy for child and self than usual, participants reported longer sleep latencies than usual. An exception to this otherwise consistent pattern was that time inadequacy for child also preceded shorter sleep hours and poorer sleep quality that night. The results highlight the utility of a daily diary design for capturing the temporal sequences linking sleep and psychosocial stressors.

61 citations


Journal ArticleDOI
TL;DR: It is argued that going to bed may not be synonymous with going to sleep, and that this fragmentation of bedtime results in a two‐step sleep displacement, and sleep displacement should be redefined as a two-step process.
Abstract: This study argues that going to bed may not be synonymous with going to sleep, and that this fragmentation of bedtime results in a two-step sleep displacement. We separated bedtime (i.e. going to bed) from shuteye time (i.e. attempting to go to sleep once in bed) and assessed the prevalence of electronic media use in both time slots. A convenience sample of 338 adults (aged 18-25 years, 67.6% women) participated in an online survey. Results indicated a gap of 39 min between bedtime and shuteye time, referred to as 'shuteye latency'. Respondents with a shuteye latency of, respectively, ≤30 min, ≤1 or >1 h, were 3.3, 6.1 and 9.3 times more likely to be rated as poor sleepers compared to those who went to sleep immediately after going to bed. Before bedtime, volume of electronic media use (17 h 55 min per week) was higher than non-media activities (14 h per week), whereas the opposite was true after bedtime (media = 3 h 41 min, non-media = 7 h 46 min). Shuteye latency was related exclusively to prebedtime media use. Findings confirmed the proposed fragmentation of bedtime. Sleep displacement should therefore be redefined as a two-step process, as respondents not only engage in the delay of bedtime, but also in the delay of shuteye time once in bed. Theoretical, methodological and practical implications are discussed.

60 citations


Journal ArticleDOI
TL;DR: Examination of the effect of age on several measures of sleep macro‐ and microstructure in 211 women of the ‘Sleep and Health in Women’ study indicates that traditional sleep stage scoring may underestimate age‐related changes in sleep.
Abstract: Summary It is well known that the quantity and quality of physiological sleep changes across age. However, so far the effect of age on sleep microstructure has been mostly addressed in small samples. The current study examines the effect of age on several measures of sleep macro- and microstructure in 211 women (22–71 years old) of the ‘Sleep and Health in Women’ study for whom ambulatory polysomnography was registered. Older age was associated with significantly lower fast spindle (effect size f2 = 0.32) and K-complex density (f2 = 0.19) during N2 sleep, as well as slow-wave activity (log) in N3 sleep (f2 = 0.21). Moreover, total sleep time (f2 = 0.10), N3 sleep (min) (f2 = 0.10), rapid eye movement sleep (min) (f2 = 0.11) and sigma (log) (f2 = 0.05) and slow-wave activity (log) during non-rapid eye movement sleep (f2 = 0.09) were reduced, and N1 sleep (f2 = 0.03) was increased in older age. No significant effects of age were observed on slow spindle density, rapid eye movement density and beta power (log) during non-rapid eye movement sleep. In conclusion, effect sizes indicate that traditional sleep stage scoring may underestimate age-related changes in sleep.

58 citations


Journal ArticleDOI
TL;DR: It is demonstrated that sleep problems are likely to become chronic for one in every third child with a sleep problem early in life and given the many negative consequences of insomnia in adulthood, these findings call for increased awareness of childhood sleep problems as a public health concern.
Abstract: Summary The aim of the current study was to assess the development and stability of sleep problems from childhood to late adolescence. This was a longitudinal cohort study of 2026 children, who completed three comprehensive health surveys, at age 7–9, 11–13 and 16–19 years. Data on difficulties with initiating and/or maintaining sleep (DIMS: assessed using a single item) and time in bed (TIB) were collected at all three waves, while insomnia assessed in line with the DSM-5 criteria and sleep duration were also assessed in the last wave. Negative binomial regression analyses were used to examine prospective associations. Sleep problems in 7–9-year-old children were found to persist into late adolescence for approximately one-third of the participants, both with regard to DIMS and short TIB. Children having chronic DIMS at the first two waves had nearly twice the risk of fulfilling the DSM-5 criteria later for insomnia in late adolescence [adjusted relative risk RR: 1.91]. Short TIB at age 11–13 was also associated with increased risk of subsequent short sleep duration (adjusted RR: 1.32) and TIB (adjusted RR: 1.40). These findings have important implications for practitioners and families. Although the majority of children will outgrow their problems once they reach late adolescence, the results also demonstrate that sleep problems are likely to become chronic for one in every third child with a sleep problem early in life. Given the many negative consequences of insomnia in adulthood, these findings call for increased awareness of childhood sleep problems as a public health concern.

58 citations


Journal ArticleDOI
TL;DR: There are multiple possible mechanisms through which morningness–eveningness affects daytime functioning in university students, and sleep characteristics are a significant mechanism.
Abstract: Summary 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.

55 citations


Journal ArticleDOI
TL;DR: Results suggest that dissociative experiences during wakefulness are reflected in dissociatives experiences during REM sleep; while sleep paralysis is related primarily to issues of sleep quality and wellbeing, lucid dreaming may reflect a continuation of greater imaginative capacity and positive imagery in waking states.
Abstract: Sleep paralysis and lucid dreaming are both dissociated experiences related to rapid eye movement (REM) sleep. Anecdotal evidence suggests that episodes of sleep paralysis and lucid dreaming are related but different experiences. In this study we test this claim systematically for the first time in an online survey with 1928 participants (age range: 18-82 years; 53% female). Confirming anecdotal evidence, sleep paralysis and lucid dreaming frequency were related positively and this association was most apparent between lucid dreaming and sleep paralysis episodes featuring vestibular-motor hallucinations. Dissociative experiences were the only common (positive) predictor of both sleep paralysis and lucid dreaming. Both experiences showed different associations with other key variables of interest: sleep paralysis was predicted by sleep quality, anxiety and life stress, whereas lucid dreaming was predicted by a positive constructive daydreaming style and vividness of sensory imagery. Overall, results suggest that dissociative experiences during wakefulness are reflected in dissociative experiences during REM sleep; while sleep paralysis is related primarily to issues of sleep quality and wellbeing, lucid dreaming may reflect a continuation of greater imaginative capacity and positive imagery in waking states.

52 citations


Journal ArticleDOI
TL;DR: 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, adding weight to the mounting evidence that delaying school start time benefits adolescent sleep.
Abstract: Summary 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.

Journal ArticleDOI
TL;DR: Night‐shift work is associated with poorer glycaemic control in patients with type 2 diabetes, and day work compared with day work was associated with significantly higher haemoglobin A1c.
Abstract: Summary The circadian system plays a role in regulating metabolism Night-shift work, a form of circadian misalignment, is associated with increased type 2 diabetes risk This study aimed to determine if night-shift workers with type 2 diabetes experience poorer glycaemic control than non-shift workers Patients with type 2 diabetes (104 unemployed, 85 day workers and 60 night-shift workers) participated Sleep duration, sleep quality, morningness–eveningness preference, depressive symptoms and dietary intake were assessed using standardized questionnaires Haemoglobin A1c levels were measured Night-shift workers had significantly higher haemoglobin A1c levels compared with others, while there were no differences between day workers and unemployed participants (median 786% versus 724% versus 709%, respectively) Additionally, night-shift workers were younger, had a higher body mass index, and consumed more daily calories than others Among night-shift workers, there were no significant differences in haemoglobin A1c levels between those performing rotating versus non-rotating shifts (P = 0856), or those with clockwise versus counterclockwise shift rotation (P = 0833) After adjusting for age, body mass index, insulin use, sleep duration, morningness–eveningness preference and percentage of daily intake from carbohydrates, night-shift work, compared with day work, was associated with significantly higher haemoglobin A1c (B = 0059, P = 0044), while there were no differences between unemployed participants and day workers (B = 0016, P = 0572) In summary, night-shift work is associated with poorer glycaemic control in patients with type 2 diabetes

Journal ArticleDOI
TL;DR: It is suggested that sustained attention in adolescents is affected negatively by sleep restriction, particularly in the early morning, and that a weekend of recovery sleep is insufficient to restore performance.
Abstract: This laboratory study investigated the impact of restricted sleep during a simulated school week on circadian phase, sleep stages and daytime functioning. Changes were examined across and within days and during a simulated weekend recovery. Participants were 12 healthy secondary school students (six male) aged 15-17 years [mean = 16.1 years, standard deviation (SD) = 0.9]. After 2 nights with 10 h (21:30-07:30 hours), time in bed was restricted to 5 h for 5 nights (02:30-07:30 hours), then returned to 10 h time in bed for 2 nights (21:30-07:30 hours). Saliva was collected in dim light on the first and last sleep restriction nights to measure melatonin onset phase. Sleep was recorded polysomnographically, and the Psychomotor Vigilance Task (PVT) and Karolinska Sleepiness Scale were undertaken 3-hourly while awake. Average phase delay measured by melatonin was 3 h (SD = 50 min). Compared to baseline, sleep during the restriction period contained a smaller percentage of Stages 1 and 2 and rapid eye movement (REM) and a greater percentage of Stage 4. PVT lapses increased significantly during sleep restriction and did not return to baseline levels during recovery. Subjective sleepiness showed a similar pattern during restriction, but returned to baseline levels during recovery. Results suggest that sustained attention in adolescents is affected negatively by sleep restriction, particularly in the early morning, and that a weekend of recovery sleep is insufficient to restore performance. The discrepancy between sleepiness ratings and performance may indicate a lack of perception of this residual impairment.

Journal ArticleDOI
TL;DR: It was concluded that sleepiness ratings are strongly associated with time of day, sleep quality, stress, work day/day off, being ill, age, and sex.
Abstract: Summary Self-rated sleepiness responds to sleep loss, time of day and work schedules. There is, however, a lack of a normative reference showing the diurnal pattern during a normal working day, compared with a day off, as well as differences depending on stress, sleep quality, sex, age and being sick listed. The present study sought to provide such data for the Karolinska Sleepiness Scale. Participants were 431 individuals working in medium-sized public service units. Sleepiness (Karolinska Sleepiness Scale, scale 1–9) was rated at six times a day for a working week and 2 days off (>90.000 ratings). The results show a clear circadian pattern, with high values during the morning (4.5 at 07:00 hours) and evening (6.0 at 22:00 hours), and with low values (3–4) during the 10:00–16:00 hours span. Women had significantly higher (0.5 units) Karolinska Sleepiness Scale values than men, as did younger individuals (0.3 units), those with stress (1.3 units above the low-stress group) and those with poor sleep quality (1.0 units above those with qood sleep quality). Days off showed reduced sleepiness (0.7 units), while being sick listed was associated with an increased sleepiness (0.8 units). Multiple regression analysis of mean sleepiness during the working week yielded mean daytime stress, mean sleep quality, age, and sex as predictors (not sleep duration). Improved sleep quality accounted for the reduced sleepiness during days off, but reduced stress was a second factor. Similar results were obtained in a longitudinal mixed-model regression analysis across the 7 days of the week. The percentage of ratings at Karolinska Sleepiness Scale risk levels (8 + 9) was 6.6%, but most of these were obtained at 22:00 hours. It was concluded that sleepiness ratings are strongly associated with time of day, sleep quality, stress, work day/day off, being ill, age, and sex.

Journal ArticleDOI
TL;DR: In response to this epidemic‐like increase in sleep disorders, their prevention, identification and aggressive treatment should become a health‐care priority of the US military.
Abstract: Sleep disorders are a critical issue for the military, as they impact operational readiness, personnel health, wellbeing and health-care costs. The incidence of insomnia and obstructive sleep apnea (OSA) are increasing in the United States civilian population, and rates in military personnel exceed those of civilians. Using a comprehensive database, rates of medical encounters for insomnia and OSA were investigated and their associations with various demographic factors examined in the total US military population [1,381,406 ± 25,123, mean ± standard deviation (SD) personnel per year] from 2005 to 2014. Encounters for insomnia increased from 16 of 1000 in 2005 to 75 of 1000 in 2014 (372%). Encounters for OSA increased from 44 of 1000 in 2005 to 273 of 1000 in 2014 (517%). Those experiencing the greatest increases in insomnia included women, individuals ≥40 years of age, blacks, senior enlisted personnel and Army personnel compared to other military services. Those experiencing the greatest rates of OSA included men, individuals ≥40 years of age, blacks, senior officers and Army personnel. Rates of insomnia and OSA increased linearly over time (R2 = 0.95-0.99; P < 0.01) for every subpopulation except those aged <20 years. In response to this epidemic-like increase in sleep disorders, their prevention, identification and aggressive treatment should become a health-care priority of the US military.

Journal ArticleDOI
TL;DR: It is suggested that acute sleep loss increases dietary intake in preschoolers both on the day of and the day after sleep restriction, which may promote weight gain over time and be a mechanism through which short sleep contributes to childhood obesity risk.
Abstract: Epidemiological findings suggest short sleep duration is associated with overweight and obesity across the lifespan. In adults, experimental sleep loss increases caloric intake more than total daily energy needs, thus leading to weight gain. To date, little is known about the relationship between sleep restriction and dietary intake in preschool children. Healthy children (n = 10; 41.2 ± 5.4 months; 5 females) followed a strict sleep schedule for 5 days before each experimental condition: 1 day of baseline sleep (nap and scheduled bedtime/wake time) and 1 day of sleep restriction (no-nap and ~2.3 h bedtime delay). Standardized parent-report dietary intake measures were obtained on baseline, sleep restriction and sleep recovery (ad libitum sleep opportunity in the 24-h following sleep restriction) days. As designed, children slept ~3 h less on the sleep restriction than the baseline day (P < 0.001), with no significant differences in sleep between baseline and recovery days (verified with actigraphy). Repeated-measures anovas indicated differences across conditions in total kilocalories, sugar, carbohydrate and fat intake (all P < 0.05; no differences in protein). Post hoc tests revealed that compared with baseline, children consumed 21% more kilocalories, 25% more sugar and 26% more carbohydrates on the day of sleep restriction, as well as 14% more kilocalories and 23% more fat on the day of sleep recovery (all P < 0.05). Findings suggest that acute sleep loss increases dietary intake in preschoolers both on the day of and the day after sleep restriction. Increased kilocalorie intake may promote weight gain over time and be a mechanism through which short sleep contributes to childhood obesity risk.

Journal ArticleDOI
TL;DR: In these patients with narcolepsy, sodium oxybate showed improvements in the sleep continuity and nocturnal sleep quality that are characteristic of disrupted nighttime sleep.
Abstract: This post hoc analysis evaluated the dose-related effects of sodium oxybate on sleep continuity and nocturnal sleep quality in patients with narcolepsy-cataplexy. Polysomnography data, including shifts to Stage N1/Wake, were from a randomized, placebo-controlled trial of sodium oxybate. Patients were ≥16 years old with a diagnosis of narcolepsy including symptoms of cataplexy and excessive daytime sleepiness. Treatment was for 8 weeks with placebo or sodium oxybate 4.5, 6 or 9 g administered as two equally divided nightly doses. Relative to baseline, significant dose-dependent reductions in the number of shifts per hour from Stages N2/3/rapid eye movement and Stages N2/3 to Stage N1/Wake were observed at week 8 with sodium oxybate (P < 0.05); sodium oxybate 6- and 9-g doses also resulted in similar reductions in shifts per hour of rapid eye movement to Stage N1/Wake (both P < 0.05). Across all shift categories, the shift reductions with sodium oxybate 9 g were significantly greater than those observed with placebo (P < 0.05). Improvements from baseline in reported sleep quality were significantly greater with sodium oxybate 4.5 and 9 g at week 8 (P < 0.05). Correlations between change from baseline in number of shifts per hour to Stage N1/Wake and cataplexy frequency, patient-reported nocturnal sleep quality, and excessive daytime sleepiness assessed using the Epworth Sleepiness Scale were numerically highest for the sodium oxybate 9-g dose across all sleep stage shift categories. In these patients with narcolepsy, sodium oxybate showed improvements in the sleep continuity and nocturnal sleep quality that are characteristic of disrupted nighttime sleep (ClinicalTrials.gov identifier NCT00049803).

Journal ArticleDOI
TL;DR: A power spectral analysis was conducted using a large database of sleep electroencephalographic recordings to evaluate differences between patients with insomnia and good sleepers, while simultaneously accounting for potentially important confounding factors of age, sex and part of the night.
Abstract: Previous studies of the differences between patients with insomnia and good sleepers with regard to quantitative electroencephalographic measures have mostly utilized small samples and consequently had limited ability to account for potentially important confounding factors of age, sex and part of the night. We conducted a power spectral analysis using a large database of sleep electroencephalographic recordings to evaluate differences between patients with insomnia (N = 803) and good sleepers (N = 811), while simultaneously accounting for these factors and their interaction. Comparisons of power as a function of age and part of the night were made between cohorts (patients with insomnia versus good sleepers) by sex. Absolute power in the delta, theta and sigma bands declined with age for both females and males. Females had significantly greater power than males at all ages, and for each band, cohort and part of the night. These sex differences were much greater than differences between patients with insomnia and good sleepers. Compared with good sleepers, patients with insomnia under age 40-45 years had reduced delta band power during Part 1 of the night. Females with insomnia over age 45 years had increased delta and theta band power in Parts 2 and 3 of the night, and males with insomnia under age 40 years had reduced theta power in Part 1. Females with insomnia had increased beta2 power in all parts of the night, and males with insomnia had reduced alpha power during all parts of the night. Relative power (the proportion that an individual frequency band contributes to the total power) decreased in the delta band and increased in all other bands with age for both cohorts, sexes and all parts of the night. This analysis provides a unique resource for quantitative information on the differences in power spectra between patients with insomnia and good sleepers accounting for age, sex and part of the night.

Journal ArticleDOI
TL;DR: This work integrated VOR changes via vHIT implementation, postural arrangement by studying both classical parameters and frequency spectra (PS) and correlation between these findings, polygraphic (PG) and subjective scores along Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS).
Abstract: Vestibular dysfunction was linked to moderate-to-severe obstructive sleep apnea syndrome (OSAS) patients in literature. However, due to a lack of knowledge among valid and recent implementations conceived to study postural control on static posturography (SP) and vestibulo-ocular reflex (VOR) gain under physiological conditions (video Head Impulse Test; vHIT), the aim of this work was to integrate (i) VOR changes via vHIT implementation, (ii) postural arrangement by studying both classical parameters and frequency spectra (PS) and (iii) correlation between these findings, polygraphic (PG) and subjective scores along Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS). Thus, 32 moderate-to-severe OSAS patients and 32 healthy subjects - studied by using PG, DHI and ESS - underwent vHIT and SP posturographic assessment. Analysis of variance was performed to disclose between-group effects and correlation analysis was implemented between otoneurological, PG, DHI and ESS values. OSAS group demonstrated a significant decay of VOR gain and an increase in both frequency spectra PS values, especially within the low-frequency interval, and in classical posturographic SP parameters. Further, positive and negative correlations between mean SaO2 and gain and low frequency interval spectra PS were found, respectively. Strengthening previous hypothesis related to brainstem chronic hypoxemia phenomena affecting vestibular network, implementation of these data could generate future attentions (i) for screening under physiological conditions postural and vestibular detriments in OSAS subjects, especially exposed at risk settings, and (ii) among PG parameters, such as mean SaO2 , to propose further reliable tools in monitoring postural and vestibular decay in these patients demonstrating PG parameters detriments.

Journal ArticleDOI
TL;DR: It is concluded that the majority of vegetative state patients retain some important circadian changes, including spindles and rapid eye movements, which are characteristic for normal sleep.
Abstract: Polysomnographic recording of night sleep was carried out in 15 patients with the diagnosis vegetative state (syn. unresponsive wakefulness syndrome). Sleep scoring was performed by three raters, and confirmed by means of a spectral power analysis of the electroencephalogram, electrooculogram and electromyogram. All patients but one exhibited at least some signs of sleep. In particular, sleep stage N1 was found in 13 patients, N2 in 14 patients, N3 in nine patients, and rapid eye movement sleep in 10 patients. Three patients exhibited all phenomena characteristic for normal sleep, including spindles and rapid eye movements. However, in all but one patient, sleep patterns were severely disturbed as compared with normative data. All patients had frequent and long periods of wakefulness during the night. In some apparent rapid eye movement sleep episodes, no eye movements were recorded. Sleep spindles were detected in five patients only, and their density was very low. We conclude that the majority of vegetative state patients retain some important circadian changes. Further studies are necessary to disentangle multiple factors potentially affecting sleep pattern of vegetative state patients.

Journal ArticleDOI
TL;DR: Subgroup analysis found that the association of long sleep duration and falls was more pronounced among Caucasians, and the lowest risk of falls was shown at 7–8 h day−1 of sleep duration.
Abstract: Summary Several epidemiological studies have linked sleep duration with falls; however, the findings yielded inconsistent results. No quantitative analysis has specifically assessed the influence of sleep duration on falls. PubMed and Embase were screened for observational studies from inception to 13 September 2016. A generic inverse-variance method was used to pool the outcome data for sleep duration categories of the lowest category versus reference, and the highest category versus reference with a random-effects model. Dose–response analysis was performed to evaluate the potential relationship of sleep duration with falls. Finally, seven eligible observational studies involving a total of 212 829 participants were included in the present meta-analysis. Compared with the reference category, both short and long sleep duration were significantly associated with falls, and the pooled odds ratios (95% confidence intervals) were 1.32 (1.21, 1.46) and 1.35 (1.17, 1.56), respectively, both with evidence of significant heterogeneity. An approximately ‘U-shaped’ curve was observed, and the lowest risk of falls was shown at 7–8 h day−1 of sleep duration. Further subgroup analysis found that the association of long sleep duration and falls was more pronounced among Caucasians. The present study is limited to its small number of included studies, considerable heterogeneity, observational study design and the large contribution of a single article. Further researches are still needed to confirm the causal association between sleep duration and falls in populations with different gender, age and ethnicity.

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TL;DR: It is concluded that interindividual differences in the parameters of the dynamics of the sleep homeostatic Process S are trait‐like.
Abstract: The sleep homeostatic Process S reflects the build-up of sleep pressure during waking and its dissipation during sleep. Process S is modelled as a saturating exponential function during waking and a decreasing exponential function during sleep. Slow wave activity is a physiological marker for non-rapid eye movement (non-REM) sleep intensity and serves as an index of Process S. There is considerable interindividual variability in the sleep homeostatic responses to sleep and sleep deprivation. The aim of this study was to investigate whether interindividual differences in Process S are trait-like. Polysomnographic recordings of 8 nights (12-h sleep opportunities, 22:00-10:00 hours) interspersed with three 36-h periods of sustained wakefulness were performed in 11 healthy young adults. Empirical mean slow wave activity per non-REM sleep episode at episode mid-points were used for parameter estimation. Parameters of Process S were estimated using different combinations of consecutive sleep recordings, resulting in two to three sets of parameters per subject. Intraclass correlation coefficients were calculated to assess whether the parameters were stable across the study protocol and they showed trait-like variability among individuals. We found that the group-average time constants of the build-up and dissipation of Process S were 19.2 and 2.7 h, respectively. Intraclass correlation coefficients ranged from 0.48 to 0.56, which reflects moderate trait variability. The time constants of the build-up and dissipation varied independently among subjects, indicating two distinct traits. We conclude that interindividual differences in the parameters of the dynamics of the sleep homeostatic Process S are trait-like.

Journal ArticleDOI
TL;DR: Both longerSleep duration and higher sleep efficiency were significantly associated with better diet quality among US Hispanic/Latino adults and the dietary components most strongly associated with sleep duration and sleep efficiency differed, suggesting potentially independent mechanisms by which each aspect of sleep impacts dietary choices.
Abstract: Summary Using a cross-sectional probability sample with actigraphy data and two 24-h dietary recalls, we quantified the association between sleep duration, continuity, variability and timing with the Alternative Healthy Eating Index-2010 diet quality score and its components in 2140 Hispanic Community Health Study/Study of Latinos participants. The Alternative Healthy Eating Index diet quality-2010 score ranges from 0 to 110, with higher scores indicating greater adherence to the dietary guidelines and lower risk from major chronic disease. None of the sleep measures was associated with total caloric intake as assessed using dietary recalls. However, both an increase in sleep duration and sleep efficiency were associated with healthier diet quality. Each standard deviation increase in sleep duration (1.05 h) and sleep efficiency (4.99%) was associated with a 0.30 point increase and 0.28 point increase, respectively, in the total Alternative Healthy Eating Index-2010 score. The component of Alternative Healthy Eating Index-2010 most strongly associated with longer sleep duration was increased nuts and legumes intake. The components of Alternative Healthy Eating Index-2010 most strongly associated with higher sleep efficiency were increased whole fruit intake and decreased sodium intake. Both longer sleep duration and higher sleep efficiency were significantly associated with better diet quality among US Hispanic/Latino adults. The dietary components most strongly associated with sleep duration and sleep efficiency differed, suggesting potentially independent mechanisms by which each aspect of sleep impacts dietary choices. Longitudinal research is needed to understand the directionality of these identified relationships and the generalizability of these data across other ethnic groups.

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TL;DR: A shorter circadian period in African Americans compared to non‐Hispanic European Americans is found, and selection pressures in Europe made men develop a slightly longer period than women to help them track dawn which could be useful for hunters, but less important for women as gatherers.
Abstract: The endogenous, free-running circadian period (τ) determines the phase relationship that an organism assumes when entrained to the 24-h day. We found a shorter circadian period in African Americans compared to non-Hispanic European Americans (24.07 versus 24.33 h). We speculate that a short circadian period, closer to 24 h, was advantageous to humans living around the equator, but when humans migrated North out of Africa, where the photoperiod changes with seasons, natural selection favoured people with longer circadian periods. Recently, in evolutionary terms, immigrants came from Europe and Africa to America ('the New World'). The Europeans were descendents of people who had lived in Europe for thousands of years with changing photoperiods (and presumably longer periods), whereas Africans had ancestors who had always lived around the equator (with shorter periods). It may have been advantageous to have a longer circadian period while living in Europe early in the evolution of humans. In our modern world, however, it is better to have a shorter period, because it helps make our circadian rhythms earlier, which is adaptive in our early-bird-dominated society. European American women had a shorter circadian period than men (24.24 versus 24.41), but there was no sex difference in African Americans (24.07 for both men and women). We speculate that selection pressures in Europe made men develop a slightly longer period than women to help them track dawn which could be useful for hunters, but less important for women as gatherers.

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TL;DR: It is demonstrated that sleep apneas are a core feature of CDKL5 disorder and a respiratory biomarker of CDkL5 deficiency in mice, and suggest that sleep‐disordered breathing should be evaluated routinely in CDKl5 patients.
Abstract: A recently discovered neurodevelopmental disorder caused by the mutation of the cyclin-dependent kinase-like 5 gene (CDKL5) entails complex autistic-like behaviours similar to Rett syndrome, but its impact upon physiological functions remains largely unexplored. Sleep-disordered breathing is common and potentially life-threatening in patients with Rett syndrome; however, evidence is limited in children with CDKL5 disorder, and is lacking altogether in adults. The aim of this study was to test whether the breathing pattern during sleep differs between adult Cdkl5 knockout (Cdkl5-KO) and wild-type (WT) mice. Using whole-body plethysmography, sleep and breathing were recorded non-invasively for 8 h during the light period. Sleep apneas occurred more frequently in Cdkl5-KO than in WT mice. A receiver operating characteristic (ROC) analysis discriminated Cdkl5-KO significantly from WT mice based on sleep apnea occurrence. These data demonstrate that sleep apneas are a core feature of CDKL5 disorder and a respiratory biomarker of CDKL5 deficiency in mice, and suggest that sleep-disordered breathing should be evaluated routinely in CDKL5 patients.

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TL;DR: The lower regional CBF values were correlated with higher clinical disease severity and leucocyte apoptosis, and the apparent correlation between systemic inflammation and cerebral perfusion may be indicative of haemodynamic alterations and their consequences in OSA.
Abstract: Systemic inflammation and alterations to regional cerebral blood flow (CBF) have been reported previously in obstructive sleep apnea (OSA). This study utilized arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI) to evaluate CBF in OSA patients and determine its relationship with systemic inflammation. Twenty male patients with moderate and severe OSA [apnea-hypopnea index (AHI) >15] and 16 healthy male volunteers (AHI <5) were recruited. Early- or late-phase changes in leucocyte apoptosis and its subsets were determined by flow cytometry. Perfusion MRI data were acquired with a pulsed continuous ASL technique. The CBF maps were compared using voxel-based statistics to determine differences between the OSA and control groups. The differences in CBF, clinical severity and leucocyte apoptosis were correlated. Exploratory groupwise comparison between the two groups revealed that the OSA patients exhibited low CBF values in the vulnerable regions. The lower regional CBF values were correlated with higher clinical disease severity and leucocyte apoptosis. OSA impairs cerebral perfusion in vulnerable regions, and this deficit is associated with increased disease severity. The apparent correlation between systemic inflammation and cerebral perfusion may be indicative of haemodynamic alterations and their consequences in OSA.

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TL;DR: A lower spike rate in phasic REM sleep is found, both within and outside the seizure onset zone, and this effect seems to be independent from the histopathological substrate and from the brain region, where epileptic activity is produced.
Abstract: Tonic and phasic rapid eye movement (REM) sleep seem to represent two different brain states exerting different effects on epileptic activity. In particular, interictal spikes are suppressed strongly during phasic REM sleep. The reason for this effect is not understood completely. A different level of synchronization in phasic and tonic REM sleep has been postulated, yet never measured directly. Here we assessed the interictal spike rate across non-REM (NREM) sleep, phasic and tonic REM sleep in nine patients affected by drug resistant focal epilepsy: five with type II focal cortical dysplasia and four with hippocampal sclerosis. Moreover, we applied different quantitative measures to evaluate the level of synchronization at the local and global scale during phasic and tonic REM sleep. We found a lower spike rate in phasic REM sleep, both within and outside the seizure onset zone. This effect seems to be independent from the histopathological substrate and from the brain region, where epileptic activity is produced (temporal versus extra-temporal). A higher level of synchronization was observed during tonic REM sleep both on a large (global) and small (local) spatial scale. Phasic REM sleep appears to be an interesting model for understanding the mechanisms of suppression of epileptic activity.

Journal ArticleDOI
TL;DR: The results suggest that each clinical sign and symptom of sleep bruxism represents different aspects of jaw motor activity during sleep.
Abstract: The aim of this study was to investigate the association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism. A total of 35 university students and staff members participated in this study after providing informed consent. All participants were divided into either a sleep bruxism group (n = 21) or a control group (n = 14), based on the following clinical diagnostic criteria: (1) reports of tooth-grinding sounds for at least two nights a week during the preceding 6 months by their sleep partner; (2) presence of tooth attrition with exposed dentin; (3) reports of morning masticatory muscle fatigue or tenderness; and (4) presence of masseter muscle hypertrophy. Video-polysomnography was performed in the sleep laboratory for two nights. Sleep bruxism episodes were measured using masseter electromyography, visually inspected and then categorized into phasic or tonic episodes. Phasic episodes were categorized further into episodes with or without grinding sounds as evaluated by audio signals. Sleep bruxism subjects with reported grinding sounds had a significantly higher total number of phasic episodes with grinding sounds than subjects without reported grinding sounds or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Similarly, sleep bruxism subjects with tooth attrition exhibited significantly longer phasic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Furthermore, sleep bruxism subjects with morning masticatory muscle fatigue or tenderness exhibited significantly longer tonic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). These results suggest that each clinical sign and symptom of sleep bruxism represents different aspects of jaw motor activity during sleep.

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TL;DR: In young adults with primary sleep bruxism, clonidine was significantly more effective in suppressing sleep bruXism than clonazepam, and may be mediated by suppression of autonomic nervous system activity and non‐rapid eye movement–rapidEye movement sleep processes.
Abstract: Summary The aim of this study was to assess the acute effects of clonazepam and clonidine on rhythmic masticatory muscle activity in young adults with primary sleep bruxism, as well as accompanying effects on sleep architecture and cardiac activity. This study used a double-blind, crossover, placebo-controlled design. Polysomnography was performed on 19 subjects [nine men and 10 women; mean age (±SE): 25.4 ± 2.7 years] for 5 nights. The first 2 nights were used for the habituation and diagnosis of sleep bruxism. The other 3 nights were randomly assigned for clonazepam (1.0 mg), clonidine (0.15 mg) or placebo (all administered 30 min before bedtime). Sleep, oromotor activity and cardiac activity variables were assessed and compared among the three drug conditions. Clonidine significantly reduced the median percentage of time spent in the rapid eye movement sleep stage compared with placebo and clonazepam. The number of rhythmic masticatory muscle activity episodes was reduced with clonidine by >30% compared with placebo and clonazepam. The reduction of rhythmic masticatory muscle activity index by clonidine was associated with an increase of mean RR intervals (slower heart rate) during quiet sleep periods and during a 70-s period before the onset of rhythmic masticatory muscle activity episodes. However, no changes in cardiac activity variables were observed for clonazepam. In young adults with primary sleep bruxism, clonidine was significantly more effective in suppressing sleep bruxism than clonazepam. The acute effects of clonidine on rhythmic masticatory muscle activity episodes may be mediated by suppression of autonomic nervous system activity and non-rapid eye movement–rapid eye movement sleep processes.

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TL;DR: Eating behaviours are responsible for the associations of diet with sleep among children, and health promotion programmes aiming to improve sleep should focus on discouraging eating behaviours such as eating alone or in front of the TV, and snacking between meals and after supper.
Abstract: Both diet quality and sleep duration of children have declined in the past decades. Several studies have suggested that diet and sleep are associated; however, it is not established which aspects of the diet are responsible for this association. Is it nutrients, food items, diet quality or eating behaviours? We surveyed 2261 grade 5 children on their dietary intake and eating behaviours, and their parents on their sleep duration and sleep quality. We performed factor analysis to identify and quantify the essential factors among 57 nutrients, 132 food items and 19 eating behaviours. We considered these essential factors along with a diet quality score in multivariate regression analyses to assess their independent associations with sleep. Nutrients, food items and diet quality did not exhibit independent associations with sleep, whereas two groupings of eating behaviours did. 'Unhealthy eating habits and environments' was independently associated with sleep. For each standard deviation increase in their factor score, children had 6 min less sleep and were 12% less likely to have sleep of good quality. 'Snacking between meals and after supper' was independently associated with sleep quality. For each standard deviation increase in its factor score, children were 7% less likely to have good quality sleep. This study demonstrates that eating behaviours are responsible for the associations of diet with sleep among children. Health promotion programmes aiming to improve sleep should therefore focus on discouraging eating behaviours such as eating alone or in front of the TV, and snacking between meals and after supper.