The Polysomnographical Meaning of Changed Sleep Quality-A Study of Treatment with Reduced Time in Bed.

BACKGROUND: Reports of poor sleep are widespread, but their link with objective sleep (polysomnography-PSG) is weak in cross-sectional studies. In contrast, the purpose of this study was to investigate the association between changes in subjective and objective sleep variables using data from a study of the reduction in time in bed (TIB). METHODS: One sleep recording was carried out at baseline and one at treatment week 5 (end of treatment) (N = 34). RESULTS: The Karolinska Sleep Quality Index improved and was correlated with improvement in sleep efficiency (r = 0.41, p < 0.05) and reduction in TIB (r = -0.47, p < 0.01) and sleep latency (r = 0.36, p < 0.05). The restorative sleep index showed similar results. Improvements in the insomnia severity index (ISI) essentially lacked correlations with changes in the PSG variables. It was suggested that the latter may be due to the ISI representing a week of subjective sleep experience, of which a single PSG night may not be representative. CONCLUSIONS: It was concluded that changes in the subjective ratings of sleep are relatively well associated with changes in the PSG-based sleep continuity variables when both describe the same sleep.

Habitual Videogame Playing Does Not Compromise Subjective Sleep Quality and Is Associated with Improved Daytime Functioning.

Research on the effects of videogames (VGs) on health has produced mixed results. Here, we assess the relationships of VG playing with sleep; chronotype; sleepiness; and levels of depression, anxiety, and stress; and how they are modulated by the level of exposure to VGs. Four hundred-and two adult participants (age = 26.2 ± 7.84; 227 F) completed an online survey including questions on VG use and a set of standardized questionnaires. The sample was divided into three groups: habitual gamers (HGs, 42.2%), nonhabitual gamers (NHGs, 36.5%), and non-gamers (NGs, 21.3%). No between-group differences emerged in sleepiness (Epworth Sleepiness Scale) or Pittsburgh Sleep Quality Index measures except the sleep disturbances subscore, which was higher in NHGs. HGs showed delayed bed- and risetimes and higher eveningness (reduced Morningness-Eveningness Questionnaire). HGs and NHGs showed higher depression subscores (Depression Anxiety Stress Scale) but remained in the subclinical range. Moreover, hours/week of VG playing predicted delayed sleep timing, lower daytime dysfunction, and lower sleepiness. Our data suggest that VG playing does not necessarily compromise sleep quality and may even benefit daytime functioning, underlining the need to reconsider the relationships between VG use and health by taking into account possible modulating factors such as habitual VG exposure.

A comparison of sleep restriction and sleep compression on objective measures of sleep: A sub-sample from a large randomised controlled trial.

Sleep restriction therapy is a central component of cognitive behavioural therapy for insomnia, but can lead to excessive sleepiness, which may impede treatment adherence. Sleep compression therapy has been suggested as a possibly gentler alternative. The aim of this study was to compare the effects of sleep restriction therapy and sleep compression therapy on objective measures of sleep, with a focus on magnitude and timing of effects. From a larger study of participants with insomnia, a sub-sample of 36 underwent polysomnographic recordings, before being randomised to either sleep restriction (n = 19) or sleep compression (n = 17) and receiving online treatment for 10 weeks. Assessments with polysomnography were also carried out after 2, 5, and 10 weeks of treatment. Data were analysed with multilevel linear mixed effect modelling. As per treatment instructions, participants in sleep restriction initially spent shorter time in bed compared with sleep compression. Participants in sleep restriction also showed an initial decrease of total sleep time, which was not seen in the sleep compression group. Both treatments led to improvements in sleep continuity variables, with a tendency for the improvements to come earlier during treatment in sleep restriction. No substantial differences were found between the two treatments 10 weeks after the treatment start. The results indicate that homeostatic sleep pressure may not be as important as a mechanism in sleep compression therapy as in sleep restriction therapy, and an investigation of other mechanisms is needed. In conclusion, the treatments led to similar changes in objective sleep at a somewhat different pace, and possibly through different mechanisms.

High sleep fragmentation parallels poor subjective sleep quality during the third wave of the Covid-19 pandemic: An actigraphic study.

Studies on sleep during the Covid-19 pandemic have mostly been conducted during the first wave of contagion (spring 2020). To follow up on two Italian studies addressing subjective sleep features during the second wave (autumn 2020), here we assess sleep during the third wave (spring 2021) in a sample of healthy adults from Campania (Southern Italy). Actigraphic data (on 2 nights) and the Pittsburgh Sleep Quality Index were collected from 82 participants (40 F, mean age: 32.5 ± 11.5 years) from 11 March to 18 April 2021, when Campania was classified as a "red zone", i.e. it was subjected to strict restrictions, only slightly looser than those characterizing the first national lockdown (spring 2020). Although objective sleep duration and architecture appeared in the normal range, the presence of disrupted sleep was indexed by a relevant degree of sleep fragmentation (number of awakenings ≥ 1 min: 12.7 ± 6.12; number of awakenings ≥ 5 min: 3.04 ± 1.52), paralleled by poor subjective sleep quality (Pittsburgh Sleep Quality Index global score: 5.77 ± 2.58). These data suggest that the relevant subjective sleep impairments reported during the first wave could have relied on subtle sleep disruptions that were undetected by the few objective sleep studies from the same period. Taken together with sleep data on previous phases of the pandemic, our findings show that the detrimental effects on sleep determined by the initial pandemic outbreak have not abated across the subsequent waves of contagion, and highlight the need for interventions addressing sleep health in global emergencies.

Gray Matter Volume Correlates of Sleepiness: A Voxel-Based Morphometry Study in Younger and Older Adults.

BACKGROUND: Subjectively experienced sleepiness is a problem in society, possibly linked with gray matter (GM) volume. Given a different sleep pattern, aging may affect such associations, possibly due to shrinking brain volume. PURPOSE: The purpose of the present study was to investigate the association between subjectively rated sleepiness and GM volume in thalamus, insula, hippocampus, and orbitofrontal cortex of young and older adults, after a normal night's sleep. METHODS: Eighty-four healthy individuals participated (46 aged 20-30 years, and 38 aged 65-75 years). Morphological brain data were collected in a 3T magnetic resonance imaging (MRI) scanner. Sleepiness was rated multiple times during the imaging sessions. RESULTS: In older, relative to younger, adults, clusters within bilateral mid-anterior insular cortex and right thalamus were negatively associated with sleepiness. Adjustment for the immediately preceding total sleep time eliminated the significant associations. CONCLUSION: Self-rated momentary sleepiness in a monotonous situation appears to be negatively associated with GM volume in clusters within both thalamus and insula in older individuals, and total sleep time seems to play a role in this association. Possibly, this suggests that larger GM volume in these clusters may be protective against sleepiness in older individuals. This notion needs confirmation in further studies.

The pain alarm response - an example of how conscious awareness shapes pain perception.

Pain is subjective and largely shaped by context, yet, little is known about the boundaries for such influences, in particular in relation to conscious awareness. Here, we investigated processing of noxious stimuli during sleep. Four experiments were performed where participants (n = 114) were exposed to repetitions of noxious heat, either when awake or during sleep. A test-phase followed where participants were awake and exposed to painful stimuli and asked to rate pain. Two control experiments included only the test-phase, without any prior pain exposures. Participants in the awake condition rated all test-phase stimuli the same. Conversely, participants who had been sleeping, and thus unaware of getting noxious heat, displayed heightened pain during the first part of the test-phase. This heightened reaction to noxious stimuli-a pain alarm response-was further pronounced in the control conditions where participants were naïve to noxious heat. Results suggest that the pain alarm response is partly dependent on conscious awareness.

Effects of late-night short-sleep on in-home polysomnography: relation to adult age and sex.

Bedtime is frequently delayed by many factors in life, and a homeostatic response to the delay may compensate partly for increased time awake and shortened sleep. Because sleep becomes shorter with age and women complain of disturbed sleep more often than men, age and sex differences in the homeostatic response to a delayed bedtime may modify the homeostatic response. The purpose of the present study was to investigate the effect of late-night short-sleep (3 h with awakening at about 07:00 hours) on in-home recorded sleep in men and women in two age groups (20-30 and 65-75 years). Results (N = 59) showed that late-night short-sleep was associated with an increase in percentage of N3 sleep and a decrease in percentage of rapid eye movement sleep, as well as decreases in several measures of sleep discontinuity and rapid eye movement density. Men showed a smaller decrease in percentage of rapid eye movement sleep than women in response to late-night short-sleep, as did older individuals of both sexes compared with younger. Older men showed a weaker percentage of N3 sleep in response to late-night short-sleep than younger men. In general, men showed a greater percentage of rapid eye movement sleep and a lower percentage of N3 sleep than women, and older individuals showed a lower percentage of N3 sleep than younger. In particular, older men showed very low levels of percentage of N3 sleep. We conclude that older males show less of a homeostatic response to late-night short-sleep. This may be an indication of impaired capacity for recovery in older men. Future studies should investigate if this pattern can be linked to gender-associated differences in morbidity and mortality.

Thank god it's Friday - sleep improved.

The weekend is usually seen as a window of recovery. Thus, sleep before a day off may be less impaired than that before a workday. However, very few polysomnographical studies have investigated this hypothesis. Therefore, the aim of the present study was to compare sleep before a workday with that before a weekend. Seventeen teachers participated. Sleep was recorded with polysomnography on one weekday night during the workweek, and on a workday (Friday) followed by a day off. Sleep diaries and actigraphs were also used. Weekend sleep showed delayed bedtime and time of rising, a longer total sleep time (45 min), increased N3 and N1, and decreased N2 and REM. Sleep spindles were reduced. The results remained after truncation to the shortest common sleep duration (5 h). The increase in N3 from weekday sleep to Friday night sleep was positively correlated with N1 change (r = 0.853, P ≤ 0.001), and negatively correlated with N2 change (r = -0.614, P ≤ 0.001). Subjective ratings showed that weekend sleep was associated with less awakening problems and lower subjective arousal during the day. The authors concluded that weekend sleep was longer, and showed increased N3 and N1. The authors suggest that the N3 increase before the day off is a result of lower stress, while the N1 increase may be an effect of sleep spindle suppression via the increase of N3 (which would suppress sleep spindles), thus reducing N2 and enhancing N1.

Stress vulnerability and the effects of moderate daily stress on sleep polysomnography and subjective sleepiness.

The purpose of this study was to investigate if and how sleep physiology is affected by naturally occurring high work stress and identify individual differences in the response of sleep to stress. Probable upcoming stress levels were estimated through weekly web questionnaire ratings. Based on the modified FIRST-scale (Ford insomnia response to stress) participants were grouped into high (n = 9) or low (n = 19) sensitivity to stress related sleep disturbances (Drake et al., 2004). Sleep was recorded in 28 teachers with polysomnography, sleep diaries and actigraphs during one high stress and one low stress condition in the participants home. EEG showed a decrease in sleep efficiency during the high stress condition. Significant interactions between group and condition were seen for REM sleep, arousals and stage transitions. The sensitive group had an increase in arousals and stage transitions during the high stress condition and a decrease in REM, whereas the opposite was seen in the resilient group. Diary ratings during the high stress condition showed higher bedtime stress and lower ratings on the awakening index (insufficient sleep and difficulties awakening). Ratings also showed lower cognitive function and preoccupation with work thoughts in the evening. KSS ratings of sleepiness increased during stress for the sensitive group. Saliva samples of cortisol showed no effect of stress. It was concluded that moderate daily stress is associated with a moderate negative effect on sleep sleep efficiency and fragmentation. A slightly stronger effect was seen in the sensitive group.

Effects of prolonged wakefulness: the role of PERIOD3 genotypes and personality traits.

The roles of personality traits, as assessed by Eysenck Personality Inventory, and of the clock gene PERIODS (PER3) were analysed on the subjective effects of prolonged wakefulness. A sample of 70 healthy participants (7 men, 63 women; M age = 24.2 yr., SD = 3.2) was studied during forced wakefulness between 7:30 p.m. and 9:30 a.m. According to Eysenck's arousal model, it was hypothesized that prolonged wakefulness might affect in a different way those classified as Introverted and Extraverted. During the forced wakefulness period, the Introverted group showed greater decrease in subjective measures of vigilance than did the Extraverted group, but no differences were observed between groups with high and low scores on Psychoticism and Neuroticism. Prolonged wakefulness had a negative effect on subjective sleepiness and mood in all three PER3 polymorphisms analysed.