scholarly journals Effects of Light on Daytime Sleep in 12 Hours Night Shift Workers: A Field Study

2019 ◽  
Vol 16 (1) ◽  
pp. 26-35
Author(s):  
Su Jung Choi ◽  
Hea Ree Park ◽  
Eun Yeon Joo
Keyword(s):  
Field Study ◽  
Night Shift ◽  
Shift Workers ◽  
Daytime Sleep

scholarly journals 0781 Impact Of Suvorexant On Total Daytime Sleep Hours In Shift Workers: A Randomized, Double-blind, Placebo-controlled Clinical Field Trial

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A297-A297
Author(s):  
J M Zeitzer ◽  
D S Joyce ◽  
A L Sterkel ◽  
Y L Quevedo ◽  
B Hernandez ◽  
...  
Keyword(s):  
Field Study ◽  
Total Sleep Time ◽  
Night Shift ◽  
Sleep Time ◽  
Placebo Condition ◽  
Double Blind ◽  
Shift Workers ◽  
Daytime Sleep ◽  
Therapeutic Mechanism ◽  
Lack Of Sleep

Abstract Introduction Many shift workers have an inability to sleep during the daytime following a night shift not due to insomnia or lack of sleep pressure, but because a circadian signal promoting wakefulness is hampering their ability to maintain sleep. We have previously hypothesized that the neuropeptide hypocretin-1 is, in part, responsible for the physiologic expression of this circadian wake signal. As such, it was our intent to determine whether a pharmacologic blockade of hypocretin would enable shift workers to obtain more daytime sleep. Methods Nineteen shift workers took part in a placebo-controlled, double-blind field study of suvorexant. Following two weeks of baseline, participants received 10 mg suvorexant/placebo for one week and were titrated upward to 20 mg suvorexant/placebo for an additional two weeks. Subjective (diaries) and objective (actigraphy) sleep were monitored throughout. No restrictions were placed on participants’ schedules. Results Both subjective and objective measures of total sleep time significantly improved in the active vs. the placebo condition, increasing by 2.08 ± 0.47 hours (diary) or 1.04 ± 0.53 hours (actigraphy) by the end of the 10 mg condition, and increasing by 2.97 ± 0.56 hours (diary) or 2.16 ± 0.75 hours (actigraphy) by the end of the 20 mg condition. Physician ratings of change in the severity of symptoms similarly improved in the active group. There were no adverse events reported in the active condition. Conclusion Robust changes in total sleep time were observed after administration of suvorexant, a dual-hypocretin antagonist, prior to daytime sleep in a field study of shift workers. The very large changes in total sleep time, coupled with the permissive nature of the therapeutic mechanism (i.e., suppressing wake rather than inducing sleep) indicate that this could be a viable and important therapy for shift workers. Support Merck Sharpe and Dohme investigator-initiated study #53236

The effect of blue-enriched white light on cognitive performances and sleepiness of night-shift workers: A field study

2017 ◽  
Vol 177 ◽  
pp. 208-214 ◽  
Author(s):  
Majid Motamedzadeh ◽  
Rostam Golmohammadi ◽  
Reza Kazemi ◽  
Rashid Heidarimoghadam
Keyword(s):  
Field Study ◽  
White Light ◽  
Night Shift ◽  
Shift Workers

scholarly journals 0007 Daytime Sleep in Night Shift Workers: Quantifying the Role of Circadian Misalignment

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A3-A3
Author(s):  
E Mann ◽  
C Sagong ◽  
A Cuamatzi Castelan ◽  
M Singh ◽  
T Roth ◽  
...  
Keyword(s):  
Sleep Duration ◽  
Sleep Disturbances ◽  
Night Shift ◽  
Sleep Onset ◽  
Sleep Onset Latency ◽  
Shift Workers ◽  
Circadian Misalignment ◽  
Daytime Sleep ◽  
Falling Asleep ◽  
Dim Light

Abstract Introduction Circadian misalignment is commonly cited as a culprit of daytime sleep disturbances in night shift workers; however, the specific impact and magnitude that circadian misalignment has on daytime sleep has not been well-characterized in larger samples of night shift workers. Methods Participants included fixed-night shift workers (n=52, ages 18–50) who completed an 8-hour daytime polysomnography (PSG) in the lab following a night shift. Measures of sleep disturbances included: difficulty falling asleep (sleep onset latency [SOL], latency to persistent sleep [LPS]), difficulty staying asleep (sleep efficiency [SE], wake after sleep onset [WASO]), and sleep duration (total sleep time [TST]). Melatonin samples were collected hourly for 24 hours under dim light (<10 lux) and used to determine dim light melatonin offset (DLMOff). Circadian misalignment (CM) was calculated as the time difference between bedtime and DLMOff (higher values represented sleeping after DLMOff), and correlated with PSG sleep variables. Results CM was significantly associated with difficulty staying asleep (WASO: r=0.48, p<0.001; SE: r=-0.45, p<0.001), and sleep duration (TST: r=-0.38, p<0.01). Specifically, every 3 hours of CM on average added 19.2 minutes of WASO and reduced TST by 15 minutes. In contrast, CM was not significantly correlated with sleep onset difficulties (SOL: r=-0.27; LPS: r=-0.02). Conclusion These data suggest that circadian misalignment in shift workers may be a better predictor of difficulties staying asleep and sleep duration during the day relative to difficulties falling asleep. Because longer work hours (10–12 hours) are common in night shift worker, it may be that sleep initiation difficulties associated with circadian misalignment is masked by elevated fatigue or an increased homeostatic drive from prolonged wakefulness. These results may help guide decisions about the magnitude of phase shifts required (e.g., with light therapy) for the desired improvement in daytime sleep. Support Support for this study was provided to PC by the NHLBI (K23HL138166)

scholarly journals Differences in Daytime Activity Levels and Daytime Sleep Between Night and Day Duty: An Observational Study in Italian Orthopedic Nurses

2021 ◽  
Vol 12 ◽  
Author(s):  
Eliana Roveda ◽  
Lucia Castelli ◽  
Letizia Galasso ◽  
Antonino Mulè ◽  
Emiliano Cè ◽  
...  
Keyword(s):  
Night Shift ◽  
Rest Period ◽  
Activity Levels ◽  
Shift Workers ◽  
Daytime Sleep ◽  
Daytime Activity ◽  
Rest Periods ◽  
Sleep Debt ◽  
Sleep Parameters ◽  
Night And Day

Working nonstandard work schedules is often associated with increased sedentary behavior and risk of sleep disorders. Night shift workers are prone to accumulating sleep debt, which they recover by sleeping during the day. The effect on daytime activity levels is unknown. The present study aims to objectively assess whether daytime sleep could affect daytime activity levels of shift worker nurses, resulting in an accumulation of their activity debt differently between working and rest periods. The study population (N = 37; mean age 41.7 ± 9.1 years) was composed of orthopedic nurses working on a rotating schedule, including either a night shift (NS) or only day/afternoon shift (DS). Actigraph monitoring lasted both on the working and the rest period. For the NS nurses, the working period recorded higher daytime activity levels than the rest period, while daytime sleep during the working and rest periods was similar. Conversely, DS nurses showed higher daytime activity levels and shorter daytime sleep during the working period. NS nurses were less active than DS nurses during the working period, probably because NS tended to have a longer daytime sleep. During the rest period, daytime activity levels for both groups were decreased. For NS nurses, sleep recorded the better sleep parameters during the rest period, while sleep parameters did not show significant differences between the working and the rest periods in DS. During the working period, NS nurses slept worse than the DS nurses. Both groups tended to accumulate a debt in daytime activity levels during the rest period. While daytime sleep may be an excellent way to counteract sleep debt and increase sleep duration over 24 h period, on the other hand, it makes nurses less active.

299 Limited Time for Sleep in Night Shift Workers is associated with Risk of Insomnia and Shift Work Disorder

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A119-A120
Author(s):  
Heidi Lammers-van der Holst ◽  
Yuan Zhang ◽  
Laura Barger ◽  
John Wise ◽  
Audra Murphy ◽  
...  
Keyword(s):  
Shift Work ◽  
Night Shift ◽  
Free Time ◽  
Shift Workers ◽  
Severe Problem ◽  
Work Activities ◽  
Daytime Sleep ◽  
Shift Work Disorder ◽  
Recovery Sleep ◽  
Insomnia Severity

Abstract Introduction Sleep deficiency is a severe problem faced by night shift workers. Approximately one-third of night workers report insomnia during daytime sleep and excessive sleepiness during nighttime work; when severe, these symptoms characterize shift work disorder (SWD). Difficulty sustaining 7 to 9 hours of sleep during the daytime is partly due to a circadian drive for wakefulness. Not much is known, however, about how non-work activities contribute to the inability to obtain recovery sleep. We sought to explore how much time night workers are able to allocate for daytime sleep, and how this relates to insomnia-like symptoms and the likelihood of developing SWD. Methods Night shift workers (n=452, 19–69 years old, 54% men) from various occupations who worked at least four night shifts per month completed an online survey. This included questions related to shift duration, hours per workday of non-optional non-work activities, self-rated sleep need, the Insomnia Severity Index (ISI) and a validated 4-item SWD screening questionnaire. For each participant, we calculated the duration of work plus non-optional activities and compared the remaining available time for sleep to their self-described sleep need. Non-parametric Chi-square analyses and Pearson correlations were conducted. Results On average, shift duration was 8.9±1.6 hours, non-optional activities were 3.6±2.9 hours, and sleep need was 7.6±1.6 hours, leaving 15% of shift workers with insufficient free time to obtain the amount of sleep they needed. The percentage of workers at high risk for SWD was significantly greater among those who did not have enough free time for sleep compared to those whose schedules allowed sufficient sleep time (72% vs. 42%; χ2=20.2, p<0.0001). We also found that shift workers with insufficient free time for sleep reported higher insomnia severity (r2=-0.20, p<0.0001). Conclusion About 15% of night workers have non-optional activities outside work that limit their time to obtain sufficient sleep, and this contributes to greater insomnia-like symptoms and increased risk for SWD. Future research should focus on understanding what these non-optional activities are and whether they differ between night and day workers. These insights will enable personalized countermeasures to maximize the sleep and health of shift workers. Support (if any) Supported by US NIH grant R01-AG044416.

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

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A296-A296
Author(s):  
S Choi ◽  
H Park ◽  
E Joo
Keyword(s):  
Sleep Quality ◽  
Light Emitting Diodes ◽  
Night Shift ◽  
Shift Workers ◽  
Melatonin Concentration ◽  
Light Emitting ◽  
Daytime Sleep ◽  
Lighting Conditions ◽  
Salivary Melatonin ◽  
Dim Light

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  

scholarly journals Alterations in Rev-ERBα/BMAL1 ratio and glycated hemoglobin in rotating shift workers: the EuRhythDia study

2021 ◽  
Author(s):  
Stefano Rizza ◽  
Alessio Luzi ◽  
Maria Mavilio ◽  
Marta Ballanti ◽  
Arianna Massimi ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Glycated Hemoglobin ◽  
Night Shift ◽  
Multivariate Regression Analysis ◽  
Peripheral Blood Mononuclear ◽  
Cross Sectional ◽  
Shift Workers ◽  
Metabolic Defects ◽  
Clock Gene Expression ◽  
Cell Counts

Abstract Objective To detect premature gluco-metabolic defects among night shift workers with disturbances in circadian rhythms. Design and methods We performed a hypothesis-generating, cross-sectional analysis of anthropometric, metabolic, lipid, and inflammation parameters, comparing active (a-NSW, n = 111) and former (f-NSW, n = 98) rotating night shift workers with diurnal workers (controls, n = 69). All participants were hospital nurses. We also evaluated the Pittsburgh Sleep Quality Index (PSQI) and assessed expression of transcription factors REV-ERBα and BMAL1 in peripheral blood mononuclear cells (PBMCs), as indicators of the molecular clock. Results Both a-NSW and f-NSW participants had significantly higher glycated hemoglobin (HbA1c) and white blood cell counts (WBC) (p < 0.001 for both), PSQI global score (p = 0.001) and diastolic blood pressure levels (p = 0.024) compared with controls. Expression of REV-ERBα/BMAL1 RNA in PBMC was significantly higher in a-NSW (p = 0.05) than in f-NSW or control participants. Multivariate regression analysis showed that working status and PSQI were independent determinants of higher HbA1c levels (p < 0.001). Conclusions We demonstrated that young, healthy night shift workers show subclinical abnormalities in HbA1c and changes in peripheral clock gene expression.

scholarly journals Effects of work organization on the occurrence and resolution of sleep disturbances among night shift workers: a longitudinal observational study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seungho Lee ◽  
Jae Bum Park ◽  
Kyung-Jong Lee ◽  
Seunghon Ham ◽  
Inchul Jeong
Keyword(s):  
Work Experience ◽  
Sleep Disturbances ◽  
Sleep Problems ◽  
Night Shift ◽  
Work Organization ◽  
Severity Index ◽  
Estimating Equation ◽  
Health Examination ◽  
Related Factors ◽  
Shift Workers

AbstractThis study aimed to investigate the association between work organization and the trajectories of insomnia patterns among night shift workers in a hospital. The health examination data of hospital workers, recorded from January 2014 to December 2018, were collected; 6765 records of 2615 night shift workers were included. Insomnia was defined as a score of ≥ 15 on the Insomnia Severity Index (ISI). Participants were categorized into five groups according to insomnia patterns derived from the analysis of their ISI scores. Work organization and socio-demographic characteristics were also investigated. Generalized estimating equation models and linear mixed models were constructed to analyze the longitudinal data. Of the total participants, 53.0% reported insomnia at least once during the follow-up period. The lack of nap opportunities and work-time control was associated with the occurrence of insomnia, whereas more than 5 years of shift work experience was related to the resolution of insomnia. All work-related factors were significantly related to insomnia risk; however, the effects were not significant in the sustained insomnia group. Although sleep problems are inevitable in night shift workers, well-designed work schedules and better work organization can help reduce the occurrence of insomnia among them.

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