Daytime Sleep Quality Research Articles

O02 Assessing SleeP in INfants with moderate-severe atopic Dermatitis by Longitudinal Evaluation (The SPINDLE study)

Abstract Introduction Atopic dermatitis (AD) is associated with sleep disruption due to pruritus, inflammation, increased transepidermal water loss (TEWL) and circadian alterations. Little is known about the impact of AD on sleep in early infancy, a critical time for neurodevelopment. The aim of this study was to deeply characterise the sleep architecture of 6-month-old infants with moderate-severe AD, compared to controls. Methods Overnight movements (defined as 10-15 seconds of movement) were measured for five consecutive nights using a novel wearable movement sensor. Infantile and parental sleep measures were reported by parents. Daytime sleep quality and quantity was measured by electroencephalogram (EEG) polysomnography. AD was assessed using clinical severity scoring, skin barrier assessment (TEWL, natural moisturising factor levels, and filaggrin mutational analysis) and inflammatory cytokine analysis by tape stripping. Results 57 controls and 33 cases were recruited. Average EASI at time of 6-month assessment was 7.2 (range 0.8-34.8). Infants with AD recorded almost twice as many overnight movements as controls (19.2 versus 11.2, p<0.05). Infants with AD slept for 13.1 hours versus 13.8 (p<0.05), and woke 3.5 times versus 1.9 (p<0.05). Infants with AD had differences in EEG sleep measures, including sleep spindle power and frequency. Mothers of cases had worse total sleep time (6.3 versus 7.1 hours, p<0.05), sleep-­onset latency (27.1 versus 12.8 minutes, p<0.05), and sleep ­efficiency. Conclusion This is the most detailed study ever performed on sleep in infants with AD using objective sleep measures, and has revealed significant effects on sleep architecture, sleep duration, and overnight movement.

Factors affecting quality of daytime and nighttime sleep among dialysis patients: A single center experience.

Hemodialysis is the most common treatment modality for patients with chronic kidney disease (CKD). Excessive daytime sleepiness and poor nighttime sleep is a common problem among these patients. Patients on maintenance hemodialysis (MHD) are regularly exposed to impaired fluid balance, which may cause overhydration of varying degree. However, the role of hydration status in sleep quality has not been explored in Indian setting. Hence, this study was undertaken to assess the factors affecting sleep quality among patients on MHD in a tertiary care hospital. Patients (N = 55) were enrolled if they aged above18 years, on MHD for at least 3 months, and gave consent. The daytime sleep quality was assessed using Epworth Sleepiness Scale (ESS) and Insomnia Severity Index (ISI). The data were analyzed using SPSS version 20 and STATA software. The mean age of the patients was 40.4 ± 14.7years. The prevalence rate of predialysis fluid overload was 85.4%. The median ESS score was 7 and ISI score was 3 indicating normal daytime sleep and not significant insomnia. Multivariate regression with variables adjustment showed that interdialytic weight gain (P = 0.33), tingling sensation (P = 0.36) and numbness (P = 0.35) were significant predictive factors for quality of sleep. The major factors affecting sleep quality were numbness, tingling sensation, and interdialytic weight gain. Fluid overload did not play any role in sleep quality. Another study may be carried out on assessment of pattern, duration, quality of sleep in multiple dialysis sessions, and effect of optimizing fluid status on the sleep parameters.

Findings from a systematic review of fatigue interventions: What's (not) being tested in mining and other industrial environments.

Fatigue negatively impacts mineworker health and safety. In this paper, we identify fatigue interventions tested on industrial shiftworkers and explore their effects and the factors that may influence application in an industrial setting such as a mine site. This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. A structured, systematic search of the literature was conducted to identify relevant studies published between 1980 and 2020. Researchers independently conducted article screening and study quality appraisals against pre-established criteria, and then extracted data and conducted a narrative synthesis of the included studies. Seven intervention studies, out of 1651 articles initially screened, were retained for narrative synthesis. Four studies tested the alerting effects of bright-light treatment, one evaluated the effectiveness of blue-light blocking glasses at improving daytime sleep quality and nighttime vigilance, and two examined whether sleep hygiene and alertness management trainings improved sleep quality or alertness. There was substantial evidence for the use of bright-light treatments to improve night shiftworker alertness, but insufficient evidence to draw conclusions about the effectiveness of blue-light blocking glasses and sleep hygiene and alertness management trainings due to the small number of studies included. Shiftworkers were mostly male and employed in industrial subsectors such as production and manufacturing, oil and gas, and transportation. No mining-specific intervention studies were identified. Future research is needed to identify effective fatigue risk management interventions for the mining industry as well as best practices for implementing these interventions with mineworkers.

FREQUENCY OF DAYTIME SLEEPINESS OF FACTORY WORKERS WORKING IN SHIFTS AND ITS EFFECT ON ANXIETY

Objective: This descriptive and cross-sectional study was conducted to examine the frequency of daytime sleepiness and its effects on anxiety in factory workers working in shifts. Methods: The population of the research consisted of 1052 workers working in two factories. The data were collected using the data collection form, Epworth Sleepiness Scale, and Beck Anxiety Inventory. Normally distributed data were presented as number, percentage, mean, and standard deviation. Independent samples t test and ANOVA were used in statistical analysis. Results: The mean Epworth Sleepiness Scale score of shift workers was 10.4 ± 4.2 and 42.8% had excessive daytime sleepiness. When the Epworth Sleepiness Scale scores and Beck Anxiety Inventory scores of the workers participating in the research were compared, it was determined that the daytime sleepiness levels of shift workers increased as anxiety risk increased, and the effect on vital characteristics was statistically significant (P < 0.05). Conclusion: Therefore, interventions, effective coping methods, and training strategies should be developed in order to improve the sleep quality, especially daytime sleep quality, and vital characteristics of shift workers.

0779 Circadian Entrainment in 12h Night Shift Workers: The Environmental Lights Matter?

Abstract Introduction Shift workers frequently suffer sleep disturbance in relation with the atypical work schedules. In particular, night shift workers are exposed to inevitable sunlight or bright indoor lights during the morning hours that may disturb their daytime sleep. We aimed to find out the optimal environmental lights to facilitate circadian entrainment of 12h-shift workers by assessing melatonin profiles in the morning and daytime sleep quality. Methods We enrolled 12h-shift female nurses working at one hospital (n=10, mean age 29.4±3.5 years). The schedules of participants are identical such as day-day-night-night shifts and four consecutive off days. Participants admitted to the laboratory at 9:00 following 2nd night shift schedule. Saliva melatonin was taken six times every 30 minute from 10:00 to 12:30 under two different lighting conditions with organic light emitting diodes (OLED) or light emitting diodes (LED) with 150 lux of light intensity. Dim light condition (10 lux) was conducted as controls. Three sessions were randomly ordered with 8-10 days intervals. Participants were allowed to sleep after 12:30 with light off and woke up ad libitum. Results Melatonin concentration had decreased gradually from 10.6±11.4 to 5.0±8.2 pg/ml. Among three different lighting conditions, there were no statistical differences in salivary melatonin and sleep parameters recorded by polysomnography. Circadian entrainment in night shift workers was defined as that salivary melatonin concentration had maintained above 5 pg/ml at the time to bed. 20% of sessions (6/30) were classified as circadian entrainment (CE) and 80% (24/30) were as non-entrainment (NE). Mean melatonin concentration was 22.1±11.2 in CE and 3.9±4.1 pg/ml in NE (p<.001). CE showed significantly shorter sleep latency (0.5±0.3 vs. 1.5±1.4 min, p=.025) and wakefulness after sleep onset (13.6±6.3 vs. 27.9±16.8%, p=.015), and higher sleep efficiency (94.6±2.6 vs. 88.7±6.3%, p=.011) than NE. The number of each lighting condition was not different between CE and NE (p=.847). Conclusion This is a preliminary study with small number of participants. We found that environmental lights including dim light did not affect daytime sleep of 12h shift workers. Instead, daytime sleep quality was influenced by circadian entrainment with higher melatonin concentration in the morning. Support

Stability and change in daytime and nighttime sleep in children attending daycare

Many young children experience insufficient or poor quality sleep, which may have implications for adjustment and cognitive performance. This study tested group-level changes and rank-order stability in both daytime and nighttime sleep parameters over a six-month period, from fall to spring, among children receiving high-quality, center-based daycare. A total of 68 preschoolers (54% girls; Mage = 3.80 years, SD = .68) participated. Sleep was assessed via actigraphy for seven days and nights; sleep duration (actual sleep minutes) and quality parameters were derived. Analyses of group-level changes indicated that children’s daytime and nighttime sleep duration did not change significantly from fall to spring. Nighttime sleep quality showed significant improvement, however, such that children had higher sleep efficiency in the spring than in the fall. Rank-order stability in both nighttime and daytime measures of sleep duration and quality was moderate, and stability in daytime sleep quality was low. Results add to a sparse literature examining stability in sleep parameters in young children using actigraphy.

Do night naps impact driving performance and daytime recovery sleep?

Short, nighttime naps are used as a fatigue countermeasure in night shift work, and may offer protective benefits on the morning commute. However, there is a concern that nighttime napping may impact upon the quality of daytime sleep. The aim of the current project was to investigate the influence of short nighttime naps (<30min) on simulated driving performance and subsequent daytime recovery sleep. Thirty-one healthy subjects (aged 21–35 y; 18 females) participated in a 3-day laboratory study. After a 9-h baseline sleep opportunity (22:00h–07:00h), subjects were kept awake the following night with random assignment to: a 10-min nap ending at 04:00h plus a 10-min nap at 07:00h; a 30-min nap ending at 04:00h; or a no-nap control. A 40-min driving simulator task was administered at 07:00h and 18:30h post-recovery sleep. All conditions had a 6-h daytime recovery sleep opportunity (10:00h–16:00h) the next day. All sleep periods were recorded polysomnographically. Compared to control, the napping conditions did not significantly impact upon simulated driving lane variability, percentage of time in a safe zone, or time to first crash on morning or evening drives (p>0.05). Short nighttime naps did not significantly affect daytime recovery total sleep time (p>0.05). Slow wave sleep (SWS) obtained during the 30-min nighttime nap resulted in a significant reduction in SWS during subsequent daytime recovery sleep (p<0.05), such that the total amount of SWS in 24-h was preserved. Therefore, short naps did not protect against performance decrements during a simulated morning commute, but they also did not adversely affect daytime recovery sleep following a night shift. Further investigation is needed to examine the optimal timing, length or combination of naps for reducing performance decrements on the morning commute, whilst still preserving daytime sleep quality.

Wearing Blue-Blockers in the Morning Could Improve Sleep of Workers on a Permanent Night Schedule: A Pilot Study

Night shiftworkers often complain of disturbed sleep during the day. This could be partly caused by morning sunlight exposure during the commute home, which tends to maintain the circadian clock on a daytime rhythm. The circadian clock is most sensitive to the blue portion of the visible spectrum, so our aim was to determine if blocking short wavelengths of light below 540 nm could improve daytime sleep quality and nighttime vigilance of night shiftworkers. Eight permanent night shiftworkers (32–56 yrs of age) of Quebec City's Canada Post distribution center were evaluated during summertime, and twenty others (24–55 yrs of age) during fall and winter. Timing, efficacy, and fragmentation of daytime sleep were analyzed over four weeks by a wrist activity monitor, and subjective vigilance was additionally assessed at the end of the night shift in the fall–winter group. The first two weeks served as baseline and the remaining two as experimental weeks when workers had to wear blue-blockers glasses, either just before leaving the workplace at the end of their shift (summer group) or 2 h before the end of the night shift (fall–winter group). They all had to wear the glasses when outside during the day until 16:00 h. When wearing the glasses, workers slept, on average ±SD, 32±29 and 34±60 more min/day, increased their sleep efficacy by 1.95±2.17% and 4.56±6.1%, and lowered their sleep fragmentation by 1.74±1.36% and 4.22±9.16% in the summer and fall–winter group, respectively. Subjective vigilance also generally improved on Fridays in the fall–winter group. Blue-blockers seem to improve daytime sleep of permanent night-shift workers.

Are Individuals' Nighttime Sleep Characteristics Prior to Shift‐Work Exposure Predictive for Parameters of Daytime Sleep after Commencing Shift Work?

This study aimed to examine prospectively whether individual nighttime sleep characteristics at baseline (prior to shift‐work exposure) are related to parameters of daytime sleep after commencing shift work. A longitudinal field study was carried out with novice police officers of the Dutch Police Force. A total of 26 subjects were examined at baseline before they entered shift work and re‐examined during follow‐up sessions after four and twelve months of shift‐work exposure. Wrist actigraphy and sleep diaries were used to study nocturnal sleep at baseline and daytime sleep after night shifts during follow‐up sessions. As outcome variables, estimated total sleep time, sleep efficiency, and subjective sleep quality were analyzed. Daytime total sleep time showed a 66 min decline during the first year of shift‐work exposure. Systematic inter‐individual differences were observed for daytime total sleep time and subjective sleep quality (explaining 53% and 38% of the variance, respectively), suggesting potential predictability of these sleep parameters. Although no predictors were found for daytime total sleep time, the subjective quality of nighttime sleep before the onset of shift work predicted 40% of the variance in the subjective quality of daytime sleep after commencing shift work. Follow‐up studies may reveal whether the subjective quality of baseline nighttime sleep also predicts long‐term overall tolerance for shift work.

How nursing staff perceive the duration and quality of sleep and levels of alertness

This study was conducted among health care personnel (registered nurses and nurse aides) in a public hospital in São Paulo, Brazil. Work was organized in 12-hour daytime or nighttime shifts, followed by 36 hours off. The study aimed to evaluate how the nursing staff perceived the duration and quality of sleep both during and off work days, as well as their perception of alertness during working hours. There were significant differences between night and day in the duration of sleep (Student t test = 10.82; p < 0.000). Quality of daytime sleep after working night shifts was perceived as worse than nighttime sleep (Wilcoxon test, Z = 2.67; p < 0.007). Significant differences were detected in self-evaluation of alertness after the 2nd, 6th, and 10th hour of night shifts (Friedman = 63.0; p < 0.00). Alertness was perceived as worse during dawn hours. This is an indication of sleepiness at work and can have serious consequences for both health care workers and patients.

Exposure to Bright Light and Darkness to Treat Physiologic Maladaptation to Night Work

Working at night results in a misalignment between the sleep-wake cycle and the output of the hypothalamic pacemaker that regulates the circadian rhythms of certain physiologic and behavioral variables. We evaluated whether such physiologic maladaptation to nighttime work could be prevented effectively by a treatment regimen of exposure to bright light during the night and darkness during the day. We assessed the functioning of the circadian pacemaker in five control and five treatment studies in order to assess the extent of adaptation in eight normal young men to a week of night work. In the control studies, on the sixth consecutive night of sedentary work in ordinary light (approximately 150 lux), the mean (+/- SEM) nadir of the endogenous temperature cycle continued to occur during the night (at 3:31 +/- 0:56 hours), indicating a lack of circadian adaptation to the nighttime work schedule. In contrast, the subjects in the treatment studies were exposed to bright light (7000 to 12,000 lux) at night and to nearly complete darkness during the day, and the temperature nadir shifted after four days of treatment to a significantly later, midafternoon hour (14:53 +/- 0:32; P less than 0.0001), indicating a successful circadian adaptation to daytime sleep and nighttime work. There were concomitant shifts in the 24-hour patterns of plasma cortisol concentration, urinary excretion rate, subjective assessment of alertness, and cognitive performance in the treatment studies. These shifts resulted in a significant improvement in both alertness and cognitive performance in the treatment group during the night-shift hours. We conclude that maladaptation of the human circadian system to night work, with its associated decline in alertness, performance, and quality of daytime sleep, can be treated effectively with scheduled exposure to bright light at night and darkness during the day.

Effects of Temazepam on Sleep Quality and Subsequent Mental Efficiency under Normal Sleeping Conditions and following Delayed Sleep Onset

A group of 24 healthy, normal sleepers participated in 2 experiments. The 1st experiment was designed to investigate the effects of 2 nocte doses of temazepam on subjective sleep quality and performance next morning. In contrast to placebo or no-capsule conditions both temazepam 10 and 20 mg improved a number of assessments of sleep quality, although no residual effects on performance were detected. The 2nd experiment was designed to study the effects of temazepam 20 mg on daytime sleeping and subsequent performance following a simulated night shift. Compared to placebo, temazepam had favourable effects on the subjective duration and quality of daytime sleep, but had no overall beneficial or detrimental residual effects on performance.