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

Clinical Sleep-Wake Disorders II: Focus on Insomnia and Circadian Rhythm Sleep Disorders

Insomnia and circadian rhythm sleep disorders affect large proportions of the population and have pronounced effects on quality of life and daytime performance. While the neurobiology of insomnia is not yet fully understood, circadian rhythm sleep disorders are assumed to be caused by a mismatch between the individual circadian phase position and the desired sleep-wake schedule. Benzodiazepines and non-benzodiazepine positive allosteric GABA_A receptor modulators improve sleep onset and maintenance in the short-term treatment of insomnia. However, tolerance and dependence are important side effects. Sedating antidepressants are frequently prescribed for insomnia, however, only few randomised controlled trials have been published so far. Melatonin and melatonin receptor agonists are considered to be an option for the treatment of insomnia especially because of their minimal abuse potential and safety. First data on orexin (aka hypocretin) receptor antagonists are promising, however, the risk-benefit ratio needs to be further evaluated. With respect to circadian rhythm sleep disorders, there is solid evidence from meta-analyses supporting the use of melatonin in jet lag disorder to accelerate entrainment to the new time zone, and in delayed sleep phase disorder to advance sleep-wake rhythms. In addition to that, there is evidence supporting the use of melatonin in patients with shift work disorder in order to promote daytime sleep after night shifts.

Shift Work and Shift Work Sleep Disorder: Clinical and Organizational Perspectives

Throughout the industrialized world, nearly one in five employees works some form of nontraditional shift. Such shift work is associated with numerous negative health consequences, ranging from cognitive complaints to cancer, as well as diminished quality of life. Furthermore, a substantial percentage of shift workers develop shift work disorder, a circadian rhythm sleep disorder characterized by excessive sleepiness, insomnia, or both as a result of shift work. In addition to adverse health consequences and diminished quality of life at the individual level, shift work disorder incurs significant costs to employers through diminished workplace performance and increased accidents and errors. Nonetheless, shift work will remain a vital component of the modern economy. This article reviews seminal and recent literature regarding shift work, with an eye toward real-world application in clinical and organizational settings.

Fragmentation of daily rhythms associates with obesity and cardiorespiratory fitness in adolescents: The HELENA study

BACKGROUND & AIMS

Chronobiology studies periodic changes in living organisms and it has been proposed as a promising approach to investigate obesity. We analyze the association of the characteristics of the rest-activity rhythms with obesity, cardiorespiratory fitness and metabolic risk in adolescents from nine European countries.

METHODS

1044 adolescents (12.5-17.5 y) were studied. Circadian health was evaluated by actigraphy with accelerometers (Actigraph GT1M). Characteristics of the daytime activity such as fragmentation (intradaily variability), estimated acrophase, and 10 h mean daytime activity index were obtained. Body composition was assessed using Bioelectrical-Impedance-Analysis, skinfold thickness, air-displacement-plethysmography and Dual-energy-X-ray-Absorptiometry. Cardiorespiratory fitness (VO_2max) and metabolic risk were studied.

RESULTS

Highly fragmented activity rhythms were associated with obesity and central adiposity (P < 0.05). Obese adolescents had ∼3 times higher odds of having a high fragmentation of daytime activity compared to normal weight adolescents OR (95% CI) = 2.8 (1.170, 6.443). A highly fragmented rhythm was also related to lower cardiorespiratory fitness and higher metabolic risk (P < 0.05) so those adolescents classified as low fitness showed a significantly higher fragmentation of daytime activity than those included in the high fitness group (P < 0.0001). Other characteristics of the rhythms such as smaller 10 h daytime mean activity index and delayed estimated acrophase were also related to obesity and metabolic risk (P < 0.05).

CONCLUSIONS

Our results indicate that the daily organization of the rest-activity cycle is more fragmented in obese and less fit adolescents and correlates with higher metabolic risk. This fact reinforces our hypothesis that disturbances in daily rhythms can be considered as sensitive markers of poorer adolescent's health.

Comparative Review of Approved Melatonin Agonists for the Treatment of Circadian Rhythm Sleep-Wake Disorders

Circadian rhythm sleep‐wake disorders (CRSWDs) are characterized by persistent or recurrent patterns of sleep disturbance related primarily to alterations of the circadian rhythm system or the misalignment between the endogenous circadian rhythm and exogenous factors that affect the timing or duration of sleep. These disorders collectively represent a significant unmet medical need, with a total prevalence in the millions, a substantial negative impact on quality of life, and a lack of studied treatments for most of these disorders. Activation of the endogenous melatonin receptors appears to play an important role in setting the circadian clock in the suprachiasmatic nucleus of the hypothalamus. Therefore, melatonin agonists, which may be able to shift and/or stabilize the circadian phase, have been identified as potential therapeutic candidates for the treatment of CRSWDs. Currently, only one melatonin receptor agonist, tasimelteon, is approved for the treatment of a CRSWD: non–24‐hour sleep‐wake disorder (or non‐24). However, three additional commercially available melatonin receptor agonists—agomelatine, prolonged‐release melatonin, and ramelteon—have been investigated for potential use for treatment of CRSWDs. Data indicate that these melatonin receptor agonists have distinct pharmacologic profiles that may help clarify their clinical use in CRSWDs. We review the pharmacokinetic and pharmacodynamic properties of these melatonin agonists and summarize their efficacy profiles when used for the treatment of CRSWDs. Further studies are needed to determine the therapeutic potential of these melatonin agonists for most CRSWDs.

Prevention of fatigue and insomnia in shift workers-a review of non-pharmacological measures

Background

Excessive fatigue and insomnia are common among shift workers and can lead to negative effects such as reduced work performance, processing errors, accidents at work, absenteeism, reduced quality of life, and symptoms of depression. Moreover, work in rotating shifts can be a risk factor for different somatic and psychiatric diseases and may contribute to poor health, especially in elder adults and women. This review aims to show non-pharmacological preventive measures against fatigue and insomnia in shift workers.

Method

Computerized literature searches in MedLine and in the Cochrane Library were performed with the following key words: shift work disorder, fatigue, insomnia, shift work, measures, treatment, therapy, strategies and coping. The search was limited to non-pharmacological studies that were conducted on human subjects and published as English-language articles in peer-reviewed journals since 1970. Additional studies were identified through the reference sections of relevant articles. Eighteen articles on fatigue in shift workers, including six original research articles with a total sample size of 3504 probands consisting of industrial workers, office employees, aircraft maintenance engineers, and non-shift workers working in simulated shifts, were analyzed, as well as seven articles on insomnia, including an original research article with a sample size of 26 media workers. Also, 4 reviews on shift work disorder were analyzed.

Main

The occurrence of fatigue and insomnia in shift workers associated with a working period is described as shift work disorder. Estimations on the prevalence of shift work disorder in shift workers vary between 5 % and about 20 %; about one in three shift workers is affected by insomnia and up to 90 % of shift workers report regular fatigue and sleepiness at the workplace. We concluded that there is a necessity for treatments to improve the sleep quality of the shift working population. The most common non-pharmacological recommendations to improve sleep quality and to reduce insomnia and fatigue were scheduling, bright light exposure, napping, psychoeducation for sleep hygiene, and cognitive-behavioral measures.

Conclusion

Some important preventive coping strategies for fatigue associated with shift work such as napping and exposure to bright light have already been investigated and are generally approved. A few studies also provide good evidence for the efficacy of cognitive-behavioral techniques in the treatment of chronic primary and comorbid insomnia. These coping strategies summarized in this paper should be considered in the workplace health promotion programs of each work environment to improve working conditions for shift workers and to save money.

Treatment of Sleep Disorders in Dementia

OPINION STATEMENT

Sleep and circadian disorders occur frequently in all types of dementia. Due to the multifactorial nature of sleep problems in dementia, we propose a structured approach to the evaluation and treatment of these patients. Primary sleep disorders such as obstructive sleep apnea should be treated first. Comorbid conditions and medications that impact sleep should be optimally managed to minimize negative effects on sleep. Patients and caregivers should maintain good sleep hygiene, and social and physical activity should be encouraged during the daytime. Given the generally benign nature of bright light therapy and melatonin, these treatments should be tried first. Pharmacological treatments should be added cautiously, due to the risk of cognitive side effects, sedation, and falls in the demented and older population. Regardless of treatment modality, it is essential to follow patients with dementia and sleep disorders closely, with serial monitoring of individual response to treatment.

Short Blue Light Pulses (30 Min) in the Morning Support a Sleep-Advancing Protocol in a Home Setting

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.

Diagnosis, Cause, and Treatment Approaches for Delayed Sleep-Wake Phase Disorder

Delayed sleep-wake phase disorder (DSWPD) is commonly defined as an inability to fall asleep and wake at societal times resulting in excessive daytime sleepiness. Although the cause is multifaceted, delays in sleep time are largely driven by misalignment between the circadian pacemaker and the desired sleep-wake timing schedule. Current treatment approaches focus on correcting the circadian delay; however, there is a lack of data investigating combined therapies for treatment of DSWPD.

Comparisons of Portable Sleep Monitors of Different Modalities: Potential as Naturalistic Sleep Recorders

BACKGROUND

Humans spend more than one-fourth of their life sleeping, and sleep quality has been significantly linked to health. However, the objective examination of ambulatory sleep quality remains a challenge, since sleep is a state of unconsciousness, which limits the reliability of self-reports. Therefore, a non-invasive, continuous, and objective method for the recording and analysis of naturalistic sleep is required.

OBJECTIVE

Portable sleep recording devices provide a suitable solution for the ambulatory analysis of sleep quality. In this study, the performance of two activity-based sleep monitors (Actiwatch and MTN-210) and a single-channel electroencephalography (EEG)-based sleep monitor (SleepScope) were compared in order to examine their reliability for the assessment of sleep quality.

METHODS

Twenty healthy adults were recruited for this study. First, data from daily activity recorded by Actiwatch and MTN-210 were compared to determine whether MTN-210, a more affordable device, could yield data similar to Actiwatch, the de facto standard. In addition, sleep detection ability was examined using data obtained by polysomnography as reference. One simple analysis included comparing the sleep/wake detection ability of Actiwatch, MTN-210, and SleepScope. Furthermore, the fidelity of sleep stage determination was examined using SleepScope in finer time resolution.

RESULTS

The results indicate that MTN-210 demonstrates an activity pattern comparable to that of Actiwatch, although their sensitivity preferences were not identical. Moreover, MTN-210 provides assessment of sleep duration comparable to that of the wrist-worn Actiwatch when MTN-210 was attached to the body. SleepScope featured superior overall sleep detection performance among the three methods tested. Furthermore, SleepScope was able to provide information regarding sleep architecture, although systemic bias was found.

CONCLUSION

The present results suggest that single-channel EEG-based sleep monitors are the superior option for the examination of naturalistic sleep. The current results pave a possible future use for reliable portable sleep assessment methods in an ambulatory rather than a laboratory setting.

Sleep, daily activity rhythms and postpartum mood: A longitudinal study across the perinatal period

Women with a diagnosis of bipolar and major depressive disorders are at higher risk to develop postpartum depression. The primary objective of this longitudinal study was to determine whether daily activity rhythms and sleep parameters differ between women with and without a history of a mood disorder across the perinatal period. A secondary objective was to determine whether changes in these parameters were associated with postpartum mood. In total, 33 women were included in this study, 15 of which had a history of a mood disorder (high-risk group) and 18 who did not (low-risk group). Sleep and daily rhythms were assessed subjectively and objectively during the third trimester (≥26 weeks gestation) and again at 6-12 weeks postpartum. Mood was also assessed at both time points. Women in the high-risk group showed greater subjective daily rhythms and sleep disturbances across the perinatal period. Objective sleep efficiency was worse in the high-risk group in the postpartum period. Changes in both subjective daily rhythms and objective sleep efficiency were predictive of changes in depressive symptoms across the perinatal period. These findings encourage the development of preventative therapeutics to ensure circadian rhythm and sleep stability throughout the perinatal period.

Annual Research Review: Sleep problems in childhood psychiatric disorders--a review of the latest science

BACKGROUND

Hippocrates flagged the value of sleep for good health. Nonetheless, historically, researchers with an interest in developmental psychopathology have largely ignored a possible role for atypical sleep. Recently, however, there has been a surge of interest in this area, perhaps reflecting increased evidence that disturbed or insufficient sleep can result in poor functioning in numerous domains. This review outlines what is known about sleep in the psychiatric diagnoses most relevant to children and for which associations with sleep are beginning to be understood. While based on a comprehensive survey of the literature, the focus of the current review is on the latest science (largely from 2010). There is a description of both concurrent and longitudinal links as well as possible mechanisms underlying associations. Preliminary treatment research is also considered which suggests that treating sleep difficulties may result in improvements in behavioural areas beyond sleep quality.

FINDINGS

To maximise progress in this field, there now needs to be: (a) greater attention to the assessment of sleep in children; (b) sleep research on a wider range of psychiatric disorders; (c) a greater focus on and examination of mechanisms underlying associations; (d) a clearer consideration of developmental questions and (e) large-scale well-designed treatment studies.

CONCLUSIONS

While sleep problems may sometimes be missed by parents and healthcare providers; hence constituting a hidden risk for other psychopathologies - knowing about these difficulties creates unique opportunities. The current excitement in this field from experts in diverse areas including developmental psychology, clinical psychology, genetics and neuropsychology should make these opportunities a reality.

Occupational Sleep Medicine

Sleep and circadian rhythms significantly impact almost all aspects of human behavior and are therefore relevant to occupational sleep medicine, which is focused predominantly around workplace productivity, safety, and health. In this article, 5 main factors that influence occupational functioning are reviewed: (1) sleep deprivation, (2) disordered sleep, (3) circadian rhythms, (4) common medical illnesses that affect sleep and sleepiness, and (5) medications that affect sleep and sleepiness. Consequences of disturbed sleep and sleepiness are also reviewed, including cognitive, emotional, and psychomotor functioning and drowsy driving.

Variability in Cumulative Habitual Sleep Duration Predicts Waking Functional Connectivity

STUDY OBJECTIVES

We examined whether interindividual differences in habitual sleep patterns, quantified as the cumulative habitual total sleep time (cTST) over a 2-w period, were reflected in waking measurements of intranetwork and internetwork functional connectivity (FC) between major nodes of three intrinsically connected networks (ICNs): default mode network (DMN), salience network (SN), and central executive network (CEN).

METHODS

Resting state functional magnetic resonance imaging (fMRI) study using seed-based FC analysis combined with 14-d wrist actigraphy, sleep diaries, and subjective questionnaires (N = 33 healthy adults, mean age 34.3, standard deviation ± 11.6 y). Data were statistically analyzed using multiple linear regression. Fourteen consecutive days of wrist actigraphy in participant's home environment and fMRI scanning on day 14 at the Birmingham University Imaging Centre. Seed-based FC analysis on ICNs from resting-state fMRI data and multiple linear regression analysis performed for each ICN seed and target. cTST was used to predict FC (controlling for age).

RESULTS

cTST was specific predictor of intranetwork FC when the mesial prefrontal cortex (MPFC) region of the DMN was used as a seed for FC, with a positive correlation between FC and cTST observed. No significant relationship between FC and cTST was seen for any pair of nodes not including the MPFC. Internetwork FC between the DMN (MPFC) and SN (right anterior insula) was also predicted by cTST, with a negative correlation observed between FC and cTST.

CONCLUSIONS

This study improves understanding of the relationship between intranetwork and internetwork functional connectivity of intrinsically connected networks (ICNs) in relation to habitual sleep quality and duration. The cumulative amount of sleep that participants achieved over a 14-d period was significantly predictive of intranetwork and inter-network functional connectivity of ICNs, an observation that may underlie the link between sleep status and cognitive performance.

Evaluation of Berlin Questionnaire Validity for Sleep Apnea Risk in Sleep Clinic Populations

INTRODUCTION

The Berlin questionnaire (BQ) is a common tool to screen for Obstructive Sleep Apnea (OSA) in the general population, but its application in the clinical sleep setting is still challenging. The aim of this study was to determine the specificity and sensitivity of the BQ compared to the apnea-hypopnea index obtained from polysomnography recordings obtained from a sleep clinic in Iran.

METHODS

We recruited 100 patients who were referred to the Sleep Disorders Research Center of Kermanshah University of Medical Sciences for the evaluation of suspected sleep-disorder breathing difficulties. Patients completed a Persian version of BQ and underwent one night of PSG. For each patient, Apnea-Hypopnea Index (AHI) was calculated to assess the diagnosis and severity of OSA. Severity of OSA was categorized as mild when AHI was between 5 and 15, moderate when it was between 15 and 30, and severe when it was more than 30.

RESULTS

BQ results categorized 65% of our patients as high risk and 35% as low risk for OSA. The sensitivity and the specificity of BQ for OSA diagnosis with AHI>5 were 77.3% and 23.1%, respectively. Positive predictive value was 68.0% and negative predictive value was 22.0%. Moreover, the area under curve was 0.53 (95% CI: 0.49 - 0.67, P=0.38).

DISCUSSION

Our findings suggested that BQ, despite its advantages in the general population, is not a precise tool to determine the risk of sleep apnea in the clinical setting, particularly in the sleep clinic population.

Evaluation of the Charité Jet Lag Scale

The first German Charité Jet Lag Scale (CJS), based on the only validated English questionnaire, was introduced in a former study. In addition to providing further jet lag investigations, this second method-comparison study aims to evaluate the CJS. Consistent interviewing methods are essential for future research in identifying possible cross-cultural tendencies, advancing jet lag definition, and establishing potential alleviation methods. Jet lag in 17 German chorus members (5 male, 12 female, mean age 42.35 ± 13.06 years) was monitored on their 2½-week trip from Germany to Argentina and back by use of actigraphy, sleep diaries, and the CJS. Cronbach’s alpha, Pearson and Lin correlations, and Bland-Altman diagrams were applied to assess CJS reliability and validity between all measurement methods. CJS study analysis results reconfirmed the prevalence of jet lag at approximately 60%. Moreover, the study assessed high Cronbach’s alpha values and significant positive correlations for several corresponding and related sleep parameters and CJS items such as total sleep time (TST) and sleep onset latency (SOL). The confidence limits in the Bland-Altman diagrams remained within the limits of earlier studies (TST ± 1 h, SOL ± 30 min). Overall, jet lag measures in this study confirmed previous jet lag studies. Evidence indicates positive reliability and validity of the CJS, with lower specificity in some parameters. We conclude that the CJS is applicable for complex jet lag studies. The findings provide support for further development of the scale and its capability as a consistent jet lag interviewing method.

Sleep Disturbances and Behavioral Disturbances in Children and Adolescents

Sleep deprivation and sleep disorders are commonly seen in children and adolescents. They are often undiagnosed and undertreated. A balance of circadian rhythm and homeostatic drive determine sleep quality, quantity, and timing, which changes across the developmental years. Environmental and lifestyle factors can affect sleep quality and quantity and lead to sleep deprivation. A comprehensive assessment of sleep disorders includes parental report, children's self-report, and school functioning. Diagnostic tools are used in diagnosing and treating sleep disorders.

Circadian Rhythm Sleep-Wake Disorders

The circadian system regulates the timing and expression of nearly all biological processes, most notably, the sleep-wake cycle, and disruption of this system can result in adverse effects on both physical and mental health. The circadian rhythm sleep-wake disorders (CRSWDs) consist of 5 disorders that are due primarily to pathology of the circadian clock or to a misalignment of the timing of the endogenous circadian rhythm with the environment. This article outlines the nature of these disorders, the association of many of these disorders with psychiatric illness, and available treatment options.

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: An American Academy of Sleep Medicine Clinical Practice Guideline

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.

Sleep Disorders Among People With Schizophrenia: Emerging Research

Up to 80 % of individuals with schizophrenia spectrum disorders experience sleep disturbances, which impact physical and mental health, as well as quality of life. In this paper, we review and integrate emerging literature, published between 2012 and 2014, regarding approaches to diagnosis and treatment of major sleep disorders for people with schizophrenia spectrum disorders, including insomnia, obstructive sleep apnea (OSA), circadian rhythm dysfunction, and restless legs syndrome (RLS). We advocate for (1) the need to evaluate the utility of nonpharmacological approaches in people with schizophrenia spectrum disorders; (2) documentation of guidelines to assist providers in clinically tailoring such interventions when their clients experience positive, negative, and/or cognitive symptoms; (3) research on the best ways providers can capitalize on clients' self-identified needs and motivation to engage in sleep treatments through shared decision making; and (4) the importance of investigating whether and how mental health and sleep treatment services should be better connected to facilitate access for people with schizophrenia spectrum disorders. Assessment and tailored treatment of sleep disorders within mental health treatment settings has the potential to reduce sleep problems and improve functioning, quality of life, and recovery of this population.

Synchrony and desynchrony in circadian clocks: impacts on learning and memory

Circadian clocks evolved under conditions of environmental variation, primarily alternating light dark cycles, to enable organisms to anticipate daily environmental events and coordinate metabolic, physiological, and behavioral activities. However, modern lifestyle and advances in technology have increased the percentage of individuals working in phases misaligned with natural circadian activity rhythms. Endogenous circadian oscillators modulate alertness, the acquisition of learning, memory formation, and the recall of memory with examples of circadian modulation of memory observed across phyla from invertebrates to humans. Cognitive performance and memory are significantly diminished when occurring out of phase with natural circadian rhythms. Disruptions in circadian regulation can lead to impairment in the formation of memories and manifestation of other cognitive deficits. This review explores the types of interactions through which the circadian clock modulates cognition, highlights recent progress in identifying mechanistic interactions between the circadian system and the processes involved in memory formation, and outlines methods used to remediate circadian perturbations and reinforce circadian adaptation.

Prescription monitoring programs and emergency department visits involving benzodiazepine misuse: Early evidence from 11 United States metropolitan areas

BACKGROUND

Emergency department (ED) visits involving benzodiazepines have increased in the United States. Most states have created prescription monitoring programs (PMPs) to improve drug prescribing safety. To determine the association between PMP implementation and ED visits involving benzodiazepine misuse, we conducted a retrospective analysis of data from 11 metropolitan areas in the United States from 2004 to 2011.

METHODS

We estimated rates of ED visits per 100,000 residents involving benzodiazepine misuse from the Drug Abuse Warning Network dataset. Dates of PMP implementation were obtained from program administrators. We used linear regression models to assess whether PMP implementation was associated with a change in ED visits involving benzodiazepines. Models were adjusted for calendar quarter, metropolitan area, and metropolitan area-specific linear time trends.

RESULTS

Rates of ED visits involving benzodiazepine misuse increased in all metropolitan areas during the study period. PMP implementation was not associated with a change in ED visits (mean difference: 0.9 [95% CI: -0.09 to 1.9] visits per 100,000 population per quarter; p=0.08). When analyzed by number of years after implementation, PMPs were associated with a higher visit rate in year one (0.8 [95% CI: 0.2-1.5]; p=0.01]), but not in year two (0.3 [95% CI: -2.1-2.8]; p=0.78) or year three or later (2.1 [95% CI: -0.4-4.7]; p=0.10).

CONCLUSION

We did not find evidence that PMP implementation was associated with reductions in ED visits involving benzodiazepine misuse. Future work should identify PMP features and capabilities that improve benzodiazepine safety.

Self-Reported Recovery from 2-Week 12-Hour Shift Work Schedules: A 14-Day Follow-Up

Background

Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work.

Methods

Sixty-one male offshore employees—20 night workers, 16 swing shift workers, and 25 day workers—rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1–11) for 14 days after an offshore tour. After the two night-work schedules, differences on the 1^st day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis.

Results

After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05–1.89) and swing shift workers (1.42, 95% confidence interval 1.03–1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found.

Conclusion

After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the 1^st day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

Sleep in the intensive care unit

Sleep is an important physiologic process, and lack of sleep is associated with a host of adverse outcomes. Basic and clinical research has documented the important role circadian rhythm plays in biologic function. Critical illness is a time of extreme vulnerability for patients, and the important role sleep may play in recovery for intensive care unit (ICU) patients is just beginning to be explored. This concise clinical review focuses on the current state of research examining sleep in critical illness. We discuss sleep and circadian rhythm abnormalities that occur in ICU patients and the challenges to measuring alterations in circadian rhythm in critical illness and review methods to measure sleep in the ICU, including polysomnography, actigraphy, and questionnaires. We discuss data on the impact of potentially modifiable disruptors to patient sleep, such as noise, light, and patient care activities, and report on potential methods to improve sleep in the setting of critical illness. Finally, we review the latest literature on sleep disturbances that persist or develop after critical illness.

Sleeping under the Ocean: Despite Total Isolation, Nuclear Submariners Maintain Their Sleep and Wake Patterns throughout Their Under Sea Mission

BACKGROUND

To assess the effects of isolation, inadequate exposure to light and specific shift work on the subjective and objective measurements of sleep and alertness of submariners.

PURPOSE

A strictly controlled randomized crossover study with the polysomnography recorded twice during the mission.

METHODS

Setting: Shift and night work with prolonged (70 days) social isolation from the real world (with no phone or Internet contact with families or friends during a routine mission aboard the "Téméraire" French Strategic Submarine with Ballistic Nuclear missiles (SSBN). Participants: 19 submariners working on a 24-hour shift for three days in a row schedule. Interventions: The participants attended two polysomnographic (PSG) recordings of night sleep on Day 21 (D21) and Day 51 (D51) of the 70-day patrol; urine cortisol levels were also taken after sleep, and subjective assessments of sleep, sleepiness, mood and anxiety on D21 and D51. The light and temperature on board were also recorded.

RESULTS

PSG analyses showed that sleep did not significantly vary in length (total sleep time) or in quality between D21 and D51. The mariners reported the same subjective sleep, sleepiness, anxiety or mood (except for a slightly worse score for confusion on D51). Blood cortisol levels did not vary significantly.

CONCLUSIONS

These results show that humans living in an isolated environment for more than two months with this specific shift schedule do not suffer from any significant effects on sleep, sleepiness and confusion between D21 and D51, when they follow an organized regular shift pattern with controlled light and temperature.

Sleep disturbances and dementia

Sleep is a complex behavioural state, the ultimate functions of which remain poorly understood. It becomes more fragmented as we age, with more night-time awakenings and greater tendency for daytime sleep. The magnitude of disordered sleep among individuals affected by dementia has been clearly demonstrated, and disturbed sleep is a major clinical problem in dementia. Comorbid insomnia and other sleep disturbances are common in patients with neurodegenerative disorders, such Alzheimer's disease and other dementing disorders. How and when sleep problems manifest themselves can depend on the type of dementia involved as well as the stage of the dementia. However, differences in sleep pattern presentation show more variation during the initial stages of dementias than they do during the later stages. Effective, pragmatic interventions are largely anecdotal and untested.

Impact of hypnotics use on daytime function and factors associated with usage by female shift work nurses

OBJECTIVE

We investigated quality of life (QOL) and work performance of hypnotics users, and explored the factors associated with multiple hypnotics usage in shift work nurses.

METHODS

We conducted a questionnaire-based, cross-sectional survey on nurses in university hospitals. We analyzed responses from 1202 nurses; 997 were female shift work nurses (82.9%), including 696 and 281 two- and three-shift workers, respectively.

RESULTS

The rate of hypnotics use was 10% (6.9% were single hypnotic users and 3.1% were multiple hypnotics users). The rate of insomnia did not differ between the single and multiple hypnotics users. However, multiple hypnotics users showed lower QOL, more severe depressive symptoms, and greater frequencies of work-related errors than those using a single hypnotic. A multiple logistic regression analysis revealed that age ≥27 years, presence of depression, eveningness chronotype, and presence of insomnia symptoms were significantly associated with hypnotics use. On the other hand, only the existence of shift work disorder (SWD) was significantly associated with usage of multiple hypnotics.

CONCLUSIONS

The present study suggested that usage of multiple hypnotics is not beneficial for relieving insomnia or for keeping better QOL in shift work nurses. It would be desirable to explore the causal relationship between SWD and multiple hypnotics use in a future longitudinal study.

Sleep in patients with remitted bipolar disorders: a meta-analysis of actigraphy studies

OBJECTIVE

Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls.

METHOD

A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI).

RESULTS

Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07).

CONCLUSION

This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms.

Sleep hygiene awareness: its relation to sleep quality and diurnal preference

Background

Sleep hygiene is a core component for psychological treatments of insomnia and essential for maintaining a satisfactory sleep. Our study aimed to measure the sleep hygiene awareness and the self-reported quality of sleep among three age groups (young adults, adults and middle-aged adults) and to determine their relation. We also measured their relation with diurnal preference.

Methods

Using an online questionnaire, we surveyed six hundred fifty two participants, recruited nationwide from the community and from the students in three main cities in Romania.

Results

Sleep hygiene awareness was moderate on the whole and significantly worse in young adults (compared to the other age groups) and in those complaining of poor sleep (compared to those with good sleep). Sleep quality was average and linked positively with diurnal preference (the more evening oriented, the poorer the sleep). Diurnal preference was not found to play a role regarding sleep hygiene awareness.

Conclusions

Our results suggest that better sleep hygiene awareness does not necessarily guarantee better sleep quality and that it may actually be an indicator of dissatisfaction with the obtained sleep.

Electronic supplementary material

The online version of this article (doi:10.1186/s40303-015-0008-2) contains supplementary material, which is available to authorized users.

Consumer sleep monitors: is there a baby in the bathwater?

The rapid expansion of consumer sleep devices is outpacing the validation data necessary to assess the potential use of these devices in clinical and research settings. Common sleep monitoring devices utilize a variety of sensors to track movement as well as cardiac and respiratory physiology. The variety of sensors and user-specific factors offer the potential, at least theoretically, for clinically relevant information. We describe the current challenges for interpretation of consumer sleep monitoring data, since the devices are mainly used in non-medical contexts (consumer use) although medically-definable sleep disorders may commonly occur in this setting. A framework for addressing questions of how certain devices might be useful is offered. We suggest that multistage validation efforts are crucially needed, from the level of sensor data and algorithm output, to extrapolations beyond healthy adults and into other populations and real-world environments.

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

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 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.

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-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.

CONCLUSIONS

A 30-min morning bright-light exposure with afternoon melatonin is an efficient treatment to phase-advance human circadian rhythms.

Current Evaluation and Management of Excessive Daytime Sleepiness

Excessive daytime sleepiness has significant impact on neurological function, and has societal implications. Sleepiness is a common feature of many neurological conditions. A careful history will often reveal one of many common causes of excessive daytime sleepiness and suggest appropriate treatment. Neurophysiological testing can provide objective assessment. Behavioural management is an important first step in management. Treatment of common concurrent sleep disorders is also essential. Currently available medications can further symptomatically improve function in many individuals. The strongest evidence base is for the treatment of narcolepsy - a prototype disorder of excessive daytime sleepiness. Currently used medications include modafinil, stimulants, and sodium oxybate amongst others. This review discusses important features in the diagnosis of daytime sleepiness in adults, and outlines a treatment approach. Further evidence-based information about the management of this common problem is essential.

Does Pilates Exercise Increase Physical Activity, Quality of Life, Latency, and Sleep Quantity in Middle-Aged People?

This prospective study assessed the effects of a 12-wk. exercise program based on the Pilates method (2 one-hr. sessions per week) on 99 sedentary middle-aged volunteers ( M age = 47.6 yr., SD = 0.8), using an accelerometry, the Pittsburgh Sleep Quality Index, and the SF-36 questionnaire to measure changes in physical activity, quality of life, sleep latency, and quantity. The variables (quality of life, sleep latency, and quantity) were compared before and after applying the Pilates program. All of the physical and emotional components of the SF-36 questionnaire showed significant improvement, and the latency and sleep quantity also showed significant increases. The results indicate that Pilates is an accessible, interesting exercise program that can generate important changes in middle age.

Circadian biomarkers in patients with bipolar disorder: promising putative predictors of lithium response

Bipolar disorder (BD) is a common, severe mental disorder with a high recurrence rate. Lithium (Li) is the cornerstone of BD treatments to reduce recurrence, suicide, and mortality risks. However, only 30% of patients treated with Li achieve complete remission, and few markers of the response to treatment have yet been identified for application in routine practice. Circadian biomarkers may be relevant predictors of individual responses to Li because (1) Li has been shown to affect circadian rhythms, (2) disrupted circadian rhythms are a core expression of susceptibility to BD, and (3) circadian abnormalities during euthymia are associated with relapses.

Impact of breast cancer treatments on sleep disturbances - A systematic review

Sleep disturbances are highly prevalent in women with breast cancer; side effects of cancer treatment may worsen pre-existing sleep problems and have been pointed to as important determinants of their incidence. Therefore, we aimed to assess the association between different types of breast cancer treatment and sleep disturbances, through a systematic review. Medline (using PubMed), CINAHL Plus with full text, PsycINFO and Cochrane Central Register of Controlled Trials (Central) were searched from inception to January 2014. Studies that evaluated samples of women with breast cancer, assessed sleep disturbances with standardized sleep-specific measures, and provided data for different cancer treatments were eligible. A total of 12 studies met the inclusion criteria. Three studies evaluated insomnia, five studies assessed sleep quality, two provide data on general sleep disturbances and two analysed specific sleep parameters. Women submitted to chemotherapy, or radiotherapy, tended to report higher levels of sleep disturbances. More heterogeneous findings were observed regarding the effect of surgical treatment and hormonal therapy. However, a sound assessment of the impact of these treatments was hampered by differences across studies regarding the outcomes assessed, reporting bias and the fact that most studies did not control for the effect of potential confounders. The present review highlights the potential relation between breast cancer treatments and sleep disturbances, particularly of chemotherapy, though more robust evidence is needed for a proper understanding of these associations.

Attitudes, beliefs, and perceptions of caregivers and rehabilitation providers about disabled children's sleep health: a qualitative study

BACKGROUND

Children with disabilities are more likely to have sleep disturbances than children without disabilities. Identifying attitudes, beliefs, knowledge, and perceptions of caregivers and health professionals is essential in developing effective intervention programs to improve disabled children's sleep health. However, no such qualitative data about adults who have key roles in the life and daytime activities of children with disabilities are available. This qualitative study aimed to understand attitudes, beliefs, knowledge, and perceptions about disabled children's sleep hygiene among caregivers and rehabilitation providers of children with disabilities.

METHODS

Twenty seven adults, including nine primary caregivers and eighteen rehabilitation providers, participated in five focus group discussions between September and December 2012 at the Rehabilitation Center in Punta Arenas, Chile. A trained facilitator guided focus group discussions using a semi-structured script. Audiotapes and transcripts of focus group discussions were reviewed and analyzed for recurrent themes.

RESULTS

Participants identified seven themes related to children's sleep hygiene: lifestyle behaviors, family factors, children's disabilities and/or comorbidities, environmental factors, adults' responsibilities for children's sleep, perception of good sleep, and parental distress about children's sleep problems. While both caregivers and rehabilitation providers recognized the importance of sleep for children's health and functioning, they differed in their understanding of how sleep hygiene practices influence sleep. Rehabilitation providers recognized the negative influence of electronics on sleep and the positive influence of sleep routines. In contrast, caregivers reported use of television/movie watching and stimulants as coping strategies for managing children's sleep problems.

CONCLUSIONS

Caregivers may benefit from better understanding the influence of electronics and stimulant use on child sleep health. Rehabilitation providers are well positioned to provide educational messages to both children and caregivers in order to change their attitudes, perceptions, and practices surrounding sleep. These qualitative data are valuable in developing intervention programs aimed at improving sleep health among children with disabilities.

Millisecond flashes of light phase delay the human circadian clock during sleep

The human circadian timing system is most sensitive to the phase-shifting effects of light during the biological nighttime, a time at which humans are most typically asleep. The overlap of sleep with peak sensitivity to the phase-shifting effects of light minimizes the effectiveness of using light as a countermeasure to circadian misalignment in humans. Most current light exposure treatments for such misalignment are mostly ineffective due to poor compliance and secondary changes that cause sleep deprivation. Using a 16-day, parallel group design, we examined whether a novel sequence of light flashes delivered during sleep could evoke phase changes in the circadian system without disrupting sleep. Healthy volunteers participated in a 2-week circadian stabilization protocol followed by a 2-night laboratory stay. During the laboratory session, they were exposed during sleep to either darkness (n = 7) or a sequence of 2-msec light flashes given every 30 sec (n = 6) from hours 2 to 3 after habitual bedtime. Changes in circadian timing (phase) and micro- and macroarchitecture of sleep were assessed. Subjects exposed to the flash sequence during sleep exhibited a delay in the timing of their circadian salivary melatonin rhythm compared with the control dark condition (p < 0.05). Confirmation that the flashes penetrated the eyelids is presented by the occurrence of an evoked response in the EEG. Despite the robust effect on circadian timing, there were no large changes in either the amount or spectral content of sleep (p values > 0.30) during the flash stimulus. Exposing sleeping individuals to 0.24 sec of light spread over an hour shifted the timing of the circadian clock and did so without major alterations to sleep itself. While a greater number of matched subjects and more research will be necessary to ascertain whether these light flashes affect sleep, our data suggest that this type of passive phototherapy might be developed as a useful treatment for circadian misalignment in humans.