Patients with primary insomnia in the sleep laboratory: do they present with typical nights of sleep?

The insensitivity of sleep to an unfamiliar sleeping environment in patients with insomnia disorder

BACKGROUND

Sleeping in an unfamiliar environment, such as a sleep laboratory, is thought to disturb sleep in healthy individuals and could express a hyperarousal state called the first night effect. Insomnia disorder (ID) is a highly prevalent health problem characterized by increased arousal during the night and daytime. Whether or not a similar phenomenon occurs in patients with ID is unclear. This study aimed to investigate the effect of an unfamiliar environment on the sleep of patients with ID.

METHODS

In an unfamiliar sleep laboratory, polysomnographic recording testing was performed for two consecutive nights in patients with ID and age- and sex-matched healthy control subjects (HC). We collected sleep diaries and questionnaires regarding sleep, medical conditions, psychological status, and health history. Sleep continuity and architecture in both groups were compared and analyzed for two consecutive nights.

RESULTS

Participants with ID (n = 39)  and HC (n = 35) demonstrated differentially poor sleep on laboratory adaptation after exposure to the sleep laboratory. Patients with ID had longer rapid eye movement (REM) latency on the first night than on the second sleep night. HC showed increased duration and percentage of N1, decreased duration and percentage of N3, and decreased REM percentage during initial nights compared to subsequent nights. The other sleep variables showed no differences between the first and second sleep nights in patients with ID and HC.

CONCLUSIONS

An unfamiliar sleep environment does not aggravate the disruption of sleep continuity and sleep architecture but only affects the REM latency in patients with ID compared with HC.

First-night effect in insomnia disorder: a systematic review and meta-analysis of polysomnographic findings

Polysomnographic studies have been performed to investigate the first-night effect in insomnia disorder. However, these studies have revealed discrepant findings. This meta-analysis aimed to summarise and quantify the characteristics of the first-night effect in insomnia disorder. We performed a systematic search of the PubMed, Medline, EMBASE, Web of Science and PsycINFO databases to identify studies published through October 2019. A total of 11,862 articles were identified, and seven studies with eight independent populations were included in the meta-analysis. A total of 639 patients with insomnia disorder and 171 healthy controls underwent more than 2 consecutive nights of in-laboratory polysomnography. Pooled results demonstrated that both variables of sleep continuity and sleep architecture, other than slow-wave sleep were significantly altered in the first-night effect in insomnia disorder. Furthermore, the results indicated that patients with insomnia disorder had a disruption of sleep continuity in the first-night effect, including increased sleep onset latency and reduced total sleep time, compared to healthy controls. Overall, the findings show that patients with insomnia disorder experience the first-night effect, rather than reverse first-night effect, and the profiles of the first-night effect in patients with insomnia are different from healthy controls. These indicate that an adaptation night is necessary when sleep continuity and sleep architecture is to be studied in patients with insomnia disorder. More well-designed studies with large samples are needed to confirm the results.

The first-night effect and the consistency of short sleep in insomnia disorder

The nature and degree of objective sleep impairments in insomnia disorder remain unclear. This issue is complicated further by potential changes in sleep architecture on the first compared with subsequent nights in the laboratory. Evidence regarding differential first-night effects in people with insomnia disorder and controls is mixed. Here, we aimed to further characterize insomnia- and night-related differences in sleep architecture. A comprehensive set of 26 sleep variables was derived from two consecutive nights of polysomnography in 61 age-matched patients with insomnia and 61 good sleeper controls. People with insomnia expressed consistently poorer sleep than controls on several variables during both nights. While poorer sleep during the first night was observed in both groups, there were qualitative differences regarding the specific sleep variables expressing a first-night effect. Short sleep (total sleep time < 6 hr) was more likely during the first night and in insomnia, although approximately 40% of patients with insomnia presenting with short sleep on night 1 no longer met this criterion on night 2, which is important given the notion of short-sleeping insomnia as a robust subtype.

Development of evening sleep homeostatic pressure in early adolescent boys

The physiological processes governing sleep regulation show maturational changes during adolescent development. To date, data are available to specify when delays in circadian timing occur; however, no longitudinal data exist to characterize the maturation of the accumulation of sleep pressure across the evening. The aim of this longitudinal study was to test whether this change in evening sleep propensity can be identified during early adolescence. Twenty pre-pubescent boys' (Mage = 10.3, SD = 0.4 years) evening sleep homeostats were assessed using a series of sleep latency tests every hour (7:30 p.m. to 3:30 a.m.) at 6-month intervals across four waves. While results revealed shorter sleep onset latencies with increasing wakefulness (p < .001), this effect was not moderated by study wave (p = .79). Evening sleep propensity thus appears to remain stable in boys during early adolescence. Future studies should expand upon these findings by using larger samples of girls as well as boys across an extended age range during the teenage years.

On the relationship between EEG spectral analysis and pre-sleep cognitive arousal in insomnia disorder: towards an integrated model of cognitive and cortical arousal

According to the hyperarousal model, insomnia is characterised by increased arousal in the cortical, cognitive, and physiological domains. However, the interaction between these arousal domains is poorly understood. The present observational case-control study aimed to investigate cortical arousal during the night, pre-sleep cognitive arousal and the relationship between these two domains. A total of 109 patients with insomnia disorder (ID) and 109 age-and gender matched healthy controls were investigated on two sleep laboratory nights. Electroencephalographic (EEG) spectral power during non-rapid eye movement (NREM) and REM sleep was analysed as a measure of cortical arousal. In addition, patients completed the Pre-Sleep Arousal Scale (PSAS), which consists of two subscales, one for cognitive arousal (PSAS-CA) and one for self-reported somatic arousal (PSAS-SA). The relationship between the subscale scores and EEG spectral power was calculated by multi- and univariate analyses of variance. During NREM and REM sleep, patients with ID showed significantly increased spectral power in the EEG gamma band. In addition, patients with ID showed significantly increased scores on both subscales of the PSAS. The PSAS-CA score was significantly associated with increased NREM and REM gamma power, whereas PSAS-SA was associated with decreases in NREM and REM gamma power. Consistent with our hypothesis, patients with ID showed increased cortical and cognitive arousal. Moreover, there was an association between these two arousal domains, which may indicate that cortical arousal during the night is (at least in part) elicited by pre-sleep worry and rumination.

Insomnia subtypes characterised by objective sleep duration and NREM spectral power and the effect of acute sleep restriction: an exploratory analysis

Insomnia disorder (ID) is a heterogeneous disorder with proposed subtypes based on objective sleep duration. We speculated that insomnia subtyping with additional power spectral analysis and measurement of response to acute sleep restriction may be informative in overall assessment of ID. To explore alternative classifications of ID subtypes, insomnia patients (n = 99) underwent two consecutive overnight sleep studies: (i) habitual sleep opportunity (polysomnography, PSG) and, (ii) two hours less sleep opportunity (electroencephalography, EEG), with the first night compared to healthy controls (n = 25). ID subtypes were derived from data-driven classification of PSG, EEG spectral power and interhemispheric EEG asymmetry index. Three insomnia subtypes with different sleep duration and NREM spectral power were identified. One subtype (n = 26) had shorter sleep duration and lower NREM delta power than healthy controls (short-sleep delta-deficient; SSDD), the second subtype (n = 51) had normal sleep duration but lower NREM delta power than healthy controls (normal-sleep delta-deficient; NSDD) and a third subtype showed (n = 22) no difference in sleep duration or delta power from healthy controls (normal neurophysiological sleep; NNS). Acute sleep restriction improved multiple objective sleep measures across all insomnia subtypes including increased delta power in SSDD and NSDD, and improvements in subjective sleep quality for SSDD (p = 0.03), with a trend observed for NSDD (p = 0.057). These exploratory results suggest evidence of novel neurophysiological insomnia subtypes that may inform sleep state misperception in ID and with further research, may provide pathways for personalised care.

The Big Five Personality Traits and Brain Arousal in the Resting State

Based on Eysenck's biopsychological trait theory, brain arousal has long been considered to explain individual differences in human personality. Yet, results from empirical studies remained inconclusive. However, most published results have been derived from small samples and, despite inherent limitations, EEG alpha power has usually served as an exclusive indicator for brain arousal. To overcome these problems, we here selected N = 468 individuals of the LIFE-Adult cohort and investigated the associations between the Big Five personality traits and brain arousal by using the validated EEG- and EOG-based analysis tool VIGALL. Our analyses revealed that participants who reported higher levels of extraversion and openness to experience, respectively, exhibited lower levels of brain arousal in the resting state. Bayesian and frequentist analysis results were especially convincing for openness to experience. Among the lower-order personality traits, we obtained the strongest evidence for neuroticism facet 'impulsivity' and reduced brain arousal. In line with this, both impulsivity and openness have previously been conceptualized as aspects of extraversion. We regard our findings as well in line with the postulations of Eysenck and consistent with the recently proposed 'arousal regulation model'. Our results also agree with meta-analytically derived effect sizes in the field of individual differences research, highlighting the need for large (collaborative) studies.

The Big Five Personality Traits and Brain Arousal in the Resting State

Based on Eysenck's biopsychological trait theory, brain arousal has long been considered to explain individual differences in human personality. Yet, results from empirical studies remained inconclusive. However, most published results have been derived from small samples and, despite inherent limitations, EEG alpha power has usually served as an exclusive indicator for brain arousal. To overcome these problems, we here selected N = 468 individuals of the LIFE-Adult cohort and investigated the associations between the Big Five personality traits and brain arousal by using the validated EEG- and EOG-based analysis tool VIGALL. Our analyses revealed that participants who reported higher levels of extraversion and openness to experience, respectively, exhibited lower levels of brain arousal in the resting state. Bayesian and frequentist analysis results were especially convincing for openness to experience. Among the lower-order personality traits, we obtained the strongest evidence for neuroticism facet 'impulsivity' and reduced brain arousal. In line with this, both impulsivity and openness have previously been conceptualized as aspects of extraversion. We regard our findings as well in line with the postulations of Eysenck and consistent with the recently proposed 'arousal regulation model'. Our results also agree with meta-analytically derived effect sizes in the field of individual differences research, highlighting the need for large (collaborative) studies.

Sleep-Wake Survival Dynamics in People with Insomnia

INTRODUCTION

Assessing objective measures of sleep fragmentation could yield important features reflecting impaired sleep quality in people with insomnia. Survival analysis allows the specific examination of the stability of NREM sleep, REM sleep and wake. The objective of this study was to assess the differences between survival dynamics of NREM sleep, REM sleep and wake between people with insomnia and healthy controls.

METHODS

We analyzed retrospective polysomnography recordings from 86 people with insomnia and 94 healthy controls. For each participant, survival dynamics of REM sleep, NREM sleep and wake were represented using Weibull distributions. We used lasso penalized parameter selection in combination with linear regression to analyze the difference between participant groups with respect to the Weibull scale and shape parameters, while correcting for age, sex, total sleep time and relevant interaction effects.

RESULTS

Significant effects of group were found for the NREM scale parameter, and for the wake scale and shape parameters. Results indicated that people with insomnia had less stable NREM sleep and more stable wake after sleep onset compared to healthy controls. Additionally, the altered distribution of wake segment lengths indicated an increased difficulty to fall asleep after longer awakenings in the insomnia group. However, these differences were mainly observed in younger participants. Significant effects of group for the survival parameters of REM sleep were not found.

CONCLUSION

As illustrated by our results, survival analysis can be very useful for disentangling different types of sleep fragmentation in people with insomnia. For instance, the current findings suggest that people with insomnia have an increased fragmentation of NREM sleep, but not necessarily of REM sleep. Additional research into the underlying mechanisms of NREM sleep fragmentation could possibly lead to a better understanding of impaired sleep quality in people with insomnia, and consequently to improved treatment.

The influence of placebo administration on the first- night effect in patients with insomnia disorder

OBJECTIVE

We aimed to investigate the effects of placebo on the first-night effect (FNE) in insomniacs.

METHODS

In sum, 36 patients with insomnia disorder who met the DSM-5 criteria were enrolled in this study. Sixteen patients with insomnia disorder were given two days of placebo intervention (placebo-administration group, PL). Twenty patients with insomnia disorder (drug-free group, DF) were not given any interventions. All participants underwent two consecutive nights of polysomnographic (PSG) testing in the sleep laboratory. Sleep diaries were recorded during one week at home before the PSG nights and on two subsequent nights.

RESULTS

The results demonstrated that compared with the DF group, sleep onset latency (SOL), time in bed (TIB) and wake after sleep onset (WASO) significantly increased and sleep efficiency (SE) significantly decreased in the first sleep lab night in the PL group (all p < 0.05). Moreover, compared with the second night, significant differences were observed in lower self-reported total sleep time (TST) and more subjective WASO during the first night in the PL group (all p < 0.05). However, no significant difference was found in the duration and percentage of N1, N2, N3 and REM between the two groups.

CONCLUSION

In patients with insomnia disorder, placebo administration may increase the occurrence of worse sleep without causing a change in the duration and percentage of N1, N2, N3 and REM on the first sleep lab night. In some cases, a placebo may not serve as treatment but may result in a nocebo effect.

Comparing primary insomnia to the insomnia occurring in major depression and general anxiety disorder

Apart from possibly distinguishing the different clinical causes of insomnia, this article explores the subjective and objective sleep differences amongst primary insomnia, major depression with insomnia and general anxiety disorder with insomnia. Subjective sleep and objective sleep of the participants were evaluated by using the Pittsburgh sleep quality index and polysomnography, respectively. We found that major depression with insomnia exhibited higher daytime dysfunction than primary insomnia; showed significantly higher values of rapid eye movement (REM) periods, time of REM sleep and percentage of REM stage; and presented lower percentage of non-rapid eye movement stage compared with primary insomnia and general anxiety disorder with insomnia (p < 0.05). General anxiety disorder with insomnia showed lower awakening number (AN) than primary insomnia, and other objective and subjective sleep values of general anxiety disorder with insomnia and primary insomnia showed no significant difference (p > 0.05). Our findings showed that major depression with insomnia increased active REM sleep and severe daytime function, which could alert clinicians to the risk of depression. Major depression with insomnia and primary insomnia may be categorically different. However, general anxiety disorder with insomnia and primary insomnia might be a continuum of a disease rather than be categorically distinct.

Association of Short Sleep Duration and Atrial Fibrillation

BACKGROUND

Short sleep may be a risk factor for atrial fibrillation. However, previous investigations have been limited by lack of objective sleep measurement and small sample size. We sought to determine the association between objectively measured sleep duration and atrial fibrillation.

METHODS

All 31,079 adult patients undergoing diagnostic polysomnography from 1999 to 2015 at multiple sites within a large hospital network were identified from electronic medical records. Prevalent atrial fibrillation was identified by continuous ECG during polysomnography. Incident atrial fibrillation was identified by diagnostic codes and 12-lead ECGs. Logistic regression and Cox proportional hazards modeling were used to examine the association of sleep duration and atrial fibrillation prevalence and incidence, respectively, adjusting for age, sex, BMI, hypertension, coronary artery disease, cerebrovascular disease, peripheral vascular disease, heart failure, and sleep apnea severity.

RESULTS

We identified 404 cases of prevalent atrial fibrillation among 30,061 individuals (mean age ± SD, 51.0 ± 14.5 years; 51.6% women) undergoing polysomnography. After adjustment, each 1-h reduction in sleep duration was associated with a 1.17-fold (95% CI, 1.11-1.30) increased risk of prevalent atrial fibrillation. Among 27,589 patients without atrial fibrillation at baseline, we identified 1,820 cases of incident atrial fibrillation over 4.6 years median follow-up. After adjustment, each 1-h reduction in sleep duration was associated with a 1.09-fold (95% CI, 1.05-1.13) increased risk for incident atrial fibrillation.

CONCLUSIONS

Short sleep duration is independently associated with prevalent and incident atrial fibrillation. Further research is needed to determine whether interventions to extend sleep can lower atrial fibrillation risk.

The use of accelerometry as a tool to measure disturbed nocturnal sleep in Parkinson's disease

Sleep disturbances are common in Parkinson’s disease (PD). We used the Parkinson’s KinetiGraph (PKG), an objective movement recording system for PD to assess night time sleep in 155 people aged over 60 and without PD (controls), 72 people with PD (PwP) and 46 subjects undergoing a Polysomnogram (PSG: 36 with sleep disorder and 10 with normal sleep). The PKG system uses a wrist worn logger to capture acceleration and derive a bradykinesia score (BKS) every 2 min over 6 days. The BKS ranges from 0–160 with higher scores associated with lesser mobility. Previously we showed that BKS > 80 were associated with day time sleep and used this to produce scores for night time sleep: Efficiency (Percent time with BKS > 80), Fragmentation (Average duration of runs of BKS > 80) and Sleep Quality (BKS > 111 as a representation of atonia). There was a fair association with BKS score and sleep level as judged by PSG. Using these PKG scores, it was possible to distinguish between normal and abnormal PSG studies with good Selectivity (86%) and Sensitivity (80%). The PKG’s sleep scores were significantly different in PD and Controls and correlated with a subject’s self-assessment (PDSS 2) of the quality, wakefulness and restlessness. Using both the PDSS 2 and the PKG, it was apparent that sleep disturbances were apparent early in disease in many PD subjects and that subjects with poor night time sleep were more likely to have day time sleepiness. This system shows promise as a quantitative score for assessing sleep in Parkinson’s disease.

A movement recording system reveals the occurrence of sleep disturbances in the early stages of Parkinson’s disease (PD). Malcolm Horne, a movement disorders expert at the University in Melbourne, and colleagues assessed night time sleep in 72 patients with PD using a wrist-worn device that captures movement patterns. The Parkinson’s KinetiGraph (PKG) system derives scores that are associated with sleep stages and correlate with patients’ self-assessment of sleep quality, wakefulness and restlessness. Significant differences between the PKG sleep scores of PD patients and age-matched healthy controls confirmed that night time sleep disturbances and day time sleepiness worsen as the disease progresses. Abnormal PKG scores were found in patients affected by the disease for only 3 years highlighting the extent to which sleep is disrupted in early-stage PD.

Is Metabolic Rate Increased in Insomnia Disorder? A Systematic Review

Background: Insomnia disorder is a highly prevalent health condition, affecting ~10-15% of the adult population worldwide. A central feature of insomnia is hyperarousal characterized as persistent and increased somatic, cognitive and cortical stimulation. Hyperarousal leads to a state of conditioned arousal that disrupts both sleep and daytime function. Research studies have shown increases in body temperature, heart rate, electroencephalographic activity, catecholamines, and oxygen consumption as a measure of metabolic rate. These findings provide evidence of increased physiological activation in insomnia however results are not consistent. The aim of the systematic review was to determine if metabolic rate in patients with insomnia is increased in keeping with the hyperarousal hypothesis. Methods: We searched Pubmed, Web of Science, CINAHL, PsycINFO, EMBASE, and Scopus databases for observational and interventional studies that have measured metabolic rate in insomnia. Study characteristics were extracted and summarized and a risk of bias was performed for each of the studies. Results: Two reviewers screened 963 abstracts with 35 articles of interest for full-text review. Four articles evaluating 75 participants were included in this systematic review. Two studies showed increased oxygen consumption across 24 h in insomnia patients compared with good-sleeping controls. One study which measured oxygen consumption at only a single timepoint showed no difference between insomnia patients and good-sleeping controls. A further study evaluating the effect of lorazepam on oxygen consumption in patients with chronic insomnia showed that lorazepam reduced metabolic rate during the night time only. Conclusions: These findings show that metabolic rate appears to be increased across 24 h in line with the hyperarousal model of insomnia. However, these increases in metabolic rate in insomnia were minor compared to good-sleeping controls and the clinical significance is unclear. Larger, methodologically robust studies are required to confirm these findings and the effect of any increase in metabolic rate on sleep-wake disturbances or pathophysiology.

Perfectionism and Polysomnography-Determined Markers of Poor Sleep

STUDY OBJECTIVES

Perfectionism has been suggested to represent a predisposing factor for poor sleep. However, previous studies have relied on self-reported measures. The association between perfectionism and poor sleep measured by polysomnography (PSG) warrants further investigation.

METHODS

The current retrospective exploratory study used the Frost Multidimensional Perfectionism Scale and PSG in an unselected sample of 334 consecutive sleep laboratory patients (140 males, 194 females, 44.6 ± 15.9 years). Data were analyzed using linear regression analyses.

RESULTS

High levels of perfectionism were associated with PSG-determined markers of poor sleep in the first sleep laboratory night. The total Frost Multidimensional Perfectionism Scale score was significantly associated with the number of nocturnal awakenings in the first sleep laboratory night. The subscales "concern over mistakes" and "personal standards" of perfectionism were significantly associated with markers of poor sleep. In contrast, there were only a few associations between perfectionism and PSG variables of the second sleep laboratory night.

CONCLUSIONS

This pattern of results suggests that high levels of perfectionism may predispose individuals to sleep disturbances in the context of acute stressors. Thus, the influence of perfectionism on poor sleep should be further investigated to improve treatment.

Insomnia with objective short sleep duration is associated with longer duration of insomnia in the Freiburg Insomnia Cohort compared to insomnia with normal sleep duration, but not with hypertension

STUDY OBJECTIVES

To replicate the association between insomnia with objective short sleep duration and hypertension, type 2 diabetes and duration of insomnia.

DESIGN

Retrospective case-control study.

SETTING

Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg.

PARTICIPANTS

328 patients with primary insomnia classified according to DSM-IV criteria (125 males, 203 females, 44.3 ± 12.2 years).

INTERVENTIONS

N/A.

MEASUREMENTS

All participants were investigated using polysomnography, blood pressure measurements, and fasting routine laboratory.

RESULTS

Insomnia patients with short sleep duration (< 6 hours) in the first night of laboratory sleep presented with a longer duration of insomnia compared to those with normal sleep duration (≥ 6 hours) in the first night of laboratory sleep. Insomnia patients who were categorised as short sleepers in either night were not more likely to suffer from hypertension (systolic blood pressure of ≥ 140 mm Hg, diastolic blood pressure of ≥ 90 mm Hg, or a previously established diagnosis). Data analysis showed that insomnia patients with objective short sleep duration were not more likely to suffer from type 2 diabetes (fasting plasma glucose level of ≥ 126 mg/dl, or a previously established diagnosis). However, the diabetes analysis was only based on a very small number of diabetes cases. As a new finding, insomnia patients who were categorised as short sleepers in either night presented with increases in liver enzyme levels.

CONCLUSIONS

The finding on insomnia duration supports the concept of two distinct sub-groups of insomnia, namely insomnia with, and without, objectively determined short sleep duration. However, our data challenges previous findings that insomnia patients with short sleep duration are more likely to suffer from hypertension.

Impaired visual processing in patients with insomnia disorder revealed by a dissociation in visual search

Insomnia disorder is associated with both subjective and objective daytime impairments. In particular, cognitive impairments are frequently reported. However, little is known about the effects of this pathology on perceptual processes. In this study we aim at evaluating the effect of insomnia disorder on visual processing by employing a visual search paradigm. Twenty-three patients with insomnia disorder and 20 healthy age- and sex-matched control subjects participated in the study. After a polysomnographic recording night patients performed a visual search task in which they had to respond to the presence/absence of a target (letter T) embedded into a set of distractors (letters Os, Xs or Ls). Target's salience and distractors' numerosity were manipulated, while accuracy and reaction times were recorded as dependent variables. The results mainly confirmed the typical effects of a visual search task. An overall delay in performing the task was observed for patients with insomnia disorder. However, distinguishing the reaction times to stimuli containing the target from reaction times to stimuli in which the target was absent, the clinical group differed from controls solely in the condition of target absent. The performance (reaction times) of the subjects correlated with the age in the control group, whereas no correlation between reaction times and age, disease duration and quality of sleep was found in patients with insomnia disorder. These results experimentally demonstrate the presence of a daytime impairment in patients with insomnia disorder revealed by a dissociation in visual search, and are discussed in the light of the hyperarousal concept of insomnia.

Sleep and mental disorders: A meta-analysis of polysomnographic research

Investigating sleep in mental disorders has the potential to reveal both disorder-specific and transdiagnostic psychophysiological mechanisms. This meta-analysis aimed at determining the polysomnographic (PSG) characteristics of several mental disorders. Relevant studies were searched through standard strategies. Controlled PSG studies evaluating sleep in affective, anxiety, eating, pervasive developmental, borderline and antisocial personality disorders, attention-deficit-hyperactivity disorder (ADHD), and schizophrenia were included. PSG variables of sleep continuity, depth, and architecture, as well as rapid-eye movement (REM) sleep were considered. Calculations were performed with the "Comprehensive Meta-Analysis" and "R" software. Using random effects modeling, for each disorder and each variable, a separate meta-analysis was conducted if at least 3 studies were available for calculation of effect sizes as standardized means (Hedges' g). Sources of variability, that is, sex, age, and mental disorders comorbidity, were evaluated in subgroup analyses. Sleep alterations were evidenced in all disorders, with the exception of ADHD and seasonal affective disorders. Sleep continuity problems were observed in most mental disorders. Sleep depth and REM pressure alterations were associated with affective, anxiety, autism and schizophrenia disorders. Comorbidity was associated with enhanced REM sleep pressure and more inhibition of sleep depth. No sleep parameter was exclusively altered in 1 condition; however, no 2 conditions shared the same PSG profile. Sleep continuity disturbances imply a transdiagnostic imbalance in the arousal system likely representing a basic dimension of mental health. Sleep depth and REM variables might play a key role in psychiatric comorbidity processes. Constellations of sleep alterations may define distinct disorders better than alterations in 1 single variable. (PsycINFO Database Record

Deficits in attention performance are associated with insufficiency of slow-wave sleep in insomnia

OBJECTIVE

Cognitive impairment is associated with insomnia. However, there is a lack of evidence suggesting a link between insomnia and cognitive dysfunction in objective testing. The objectives of our current study were to assess the differences in components of attentional performance between primary insomnia patients and normal-sleeping controls and to examine potential predictors of attention impairment in patients with insomnia.

METHODS

We studied 36 patients (age 40.39 ± 12.36 years; 57.1% male) with insomnia and 25 normal-sleeping controls (age 39.88 ± 12.50 years; 52.9% male) who underwent one-night polysomnography followed by Multiple Sleep Latency Test (MSLT) and Attention Network Task (ANT). ANT reflected three attentional networks termed the alerting, orienting, and executive control networks.

RESULTS

After controlling for age, gender, body mass index, depression, anxiety, and education levels, patients with insomnia scored higher on the executive control variable of the ANT compared with normal-sleeping controls (96.75 ± 7.60 vs. 57.00 ± 10.49, p = 0.01). This higher score was independently associated with insufficiency of slow-wave sleep during nighttime sleep (β = -0.38, p = 0.04).

CONCLUSION

Our findings suggest that insomnia is associated with deficits in executive control of attention and that the underlying mechanism may be insufficiency of slow-wave sleep in chronic insomnia.

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.

Acute stress alters autonomic modulation during sleep in women approaching menopause

Hot flashes, hormones, and psychosocial factors contribute to insomnia risk in the context of the menopausal transition. Stress is a well-recognized factor implicated in the pathophysiology of insomnia; however the impact of stress on sleep and sleep-related processes in perimenopausal women remains largely unknown. We investigated the effect of an acute experimental stress (impending Trier Social Stress Task in the morning) on pre-sleep measures of cortisol and autonomic arousal in perimenopausal women with and without insomnia that developed in the context of the menopausal transition. In addition, we assessed the macro- and micro-structure of sleep and autonomic functioning during sleep. Following adaptation to the laboratory, twenty two women with (age: 50.4 ± 3.2 years) and eighteen women without (age: 48.5 ± 2.3 years) insomnia had two randomized in-lab overnight recordings: baseline and stress nights. Anticipation of the task resulted in higher pre-sleep salivary cortisol levels and perceived tension, faster heart rate and lower vagal activity, based on heart rate variability measures, in both groups of women. The effect of the stress manipulation on the autonomic nervous system extended into the first 4 h of the night in both groups. However, vagal tone recovered 4-6 h into the stress night in controls but not in the insomnia group. Sleep macrostructure was largely unaltered by the stress, apart from a delayed latency to REM sleep in both groups. Quantitative analysis of non-rapid eye movement sleep microstructure revealed greater electroencephalographic (EEG) power in the beta1 range (15-≤23 Hz), reflecting greater EEG arousal during sleep, on the stress night compared to baseline, in the insomnia group. Hot flash frequency remained similar on both nights for both groups. These results show that pre-sleep stress impacts autonomic nervous system functioning before and during sleep in perimenopausal women with and without insomnia. Findings also indicate that women with insomnia had increased EEG arousal and lacked recovery in vagal activity across the stress night suggesting a greater sensitivity to stress in this group.

Gender Differences in Real-Home Sleep of Young and Older Couples

STUDY OBJECTIVES

To understand gender differences in sleep quality, architecture and duration of young healthy couples in comparison to older couples in their natural sleep environment.

DESIGN

Sleep was monitored in a naturalistic setting using a headband sleep monitoring device over a period of two weeks for young couples and home polysomnography for the older couples.

PARTICIPANTS

Ten heterosexual young couples (male mean age: 28.2±1.0[SD] years/female mean age: 26.8±0.9 years) and 14 older couples (male mean age: 59.3±9.6 years/female mean age: 58.8±9.1 years).

MEASUREMENTS AND RESULTS

In the young couples, total sleep time (395±66 vs. 367±54 min., p<0.05), sleep efficiency (97.0±3.0 vs. 91.1±7.9, p<0.001), and % REM (31.1±4.8 vs. 23.6±5.5, p<0.001) in males was higher than in females. In contrast, % light sleep (51.7±7.1 vs. 59.7±6.7, p<0.001) and number of arousals (2.9±1.9 vs. 5.3±1.9, p<0.001) were lower. These differences persisted after controlling for evening mood and various evening pre-sleep activities. In the older couples, there were no differences between genders. In addition, children in the household adversely impacted sleep.

CONCLUSIONS

In couples recorded in the home, young males slept longer and had better sleep quality than young females. This difference appears to dissipate with age. In-home assessment of couples can aid in understanding of gender differences in sleep and how they are affected by age and social environment.