Circadian principles and design of rotating shift work schedules

1986 ◽  
Vol 251 (3) ◽  
pp. R636-R638 ◽  
Author(s):  
F. W. Turek
Keyword(s):  
Circadian Rhythms ◽  
Shift Work ◽  
Sleep Time ◽  
New Work ◽  
Work Schedules ◽  
Work Schedule ◽  
Work Time ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

Circadian rhythms may be disrupted when shift workers rotate from one work schedule to another. It has been suggested that in order to minimize the time needed to readjust circadian rhythms to a new work schedule the work time of shift workers should be rotated in a delaying rather than an advancing direction. However, delaying or advancing the work time does not imply that the sleep-wake cycle is also shifted in a similar manner. Indeed, after a complete rotation between the day, evening, and night shifts the sleep time will be advanced once, delayed once, and not shifted once, regardless of whether the workers are on a delaying or an advancing work rotation schedule. Thus circadian rhythms are likely to be perturbed in a similar manner whether the work schedule is rotated in a delaying or an advancing direction.

scholarly journals Disturbances of Autonomic Regulation of Cardiovascular System at Different Working Regimes with Night Shifts

Kardiologiia ◽  
2020 ◽  
Vol 60 (9) ◽  
pp. 62-67
Author(s):  
Yu. A. Merkulov ◽  
A. A. Pyatkov ◽  
S. G. Gorokhova ◽  
D. M. Merkulova ◽  
O. Yu. Atkov
Keyword(s):  
Shift Work ◽  
Spectral Characteristics ◽  
Night Shift ◽  
Autonomic Regulation ◽  
Total Power ◽  
Orthostatic Test ◽  
Heart Rhythm Variability ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

Aim        To study temporal and spectral characteristics of heart rhythm variability (HRV) in night shift workers.Materials and methods       Along with traditional risk factors, conditions of labor contribute to development of cardiovascular morbidity, including night shift work, which can be associated with disorders of the autonomic regulation detected by analysis of HRV. This study included 100 healthy men. 74 of them were engaged in shift work, including 53 men with rotating shift work, 21 men with fixed night shifts, and 26 men with day-time work. HRV was analyzed by data of 5-min electrocardiogram recording (background recording and orthostatic test).Results   Night-shift workers had decreases in total power of regulation (ТР, SDNN) and in the parasympathetic branch (HF, pNN50). Rotating night-shift workers displayed significant decreases in SDNN and pNN50 and pronounced changes in the VLF / LF / HF ratio in the orthostatic test.Conclusion            In work with night shifts, the type of autonomic regulation differs from the “standard” functioning of the autonomic nervous system (ANS). This study showed different effects of night work regimens on HRV indexes. With the rotating shift work, the ANS dysregulation was more profound and was evident by a significant decrease in the ANS total tone and parasympathetic activity (SDNN, pNN50) compared to night shifts with fixed working hours. The excessive weakening of the parasympathetic component in the passive orthostatic test can be considered as an early marker for ANS maladaptation. 

scholarly journals Designing Light for Night Shift Workers: Application of Nonvisual Lighting Design Principles in an Industrial Production Line

2021 ◽  
Vol 11 (22) ◽  
pp. 10896
Author(s):  
Johannes Zauner ◽  
Herbert Plischke
Keyword(s):  
Shift Work ◽  
Industrial Production ◽  
Night Shift ◽  
Stimulus Range ◽  
Automation System ◽  
Shift Workers ◽  
Health And Wellbeing ◽  
Rotating Shift Work ◽  
Lighting Simulation ◽  
Night Shifts

Chronodisruption deteriorates the health and wellbeing of shift workers. Artificial light at night and the lack of light during the day are major contributors to chronodisruption and need to be optimized in shift work scenarios. Here, we present one solution for a lighting and automation system in an industrial production workplace. The setting is a rapidly rotating shift work environment with morning, evening, and night shifts. We describe a procedure to specify the new lighting through a software-agnostic nonvisual lighting simulation for artificial and daylighting scenarios. Through this process, a new luminaire is created, called Drosa, that allows for a large melanopic stimulus range between 412 and 73 lx melanopic equivalent daylight (D65) illuminance vertically at eye level, while maintaining a neutral white illuminance at task level between 1250 and 900 lx, respectively. This is possible through a combination of glare-free spotlights with adjustable areal wing lights. An individually programmed automation system controls the light dosage and timing during the day and night. The work is relevant for other shift work scenarios, where the presented example and the discussed rationale behind the automation might provide insights. The work is further relevant for other lighting scenarios beyond industrial shift work, as the nonvisual lighting simulation process can be adapted to any context.

Abstract 14384: Light Therapy Improves Circadian Blood Pressure Control and Glucose Homeostasis in Rotating Night Shift Workers via Mechanisms Independent of Melatonin

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Juliane Hannemann ◽  
Anika Laing ◽  
Benita Middleton ◽  
Jonathan Cridland ◽  
Bart Staels ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Circadian Rhythms ◽  
Glucose Tolerance ◽  
Shift Work ◽  
Therapy Group ◽  
Night Shift ◽  
Light Therapy ◽  
Pressure Control ◽  
Shift Workers ◽  
Night Shifts

Introduction: Night shift work is associated with high rates of hypertension, heart disease, and metabolic syndrome. These cardiometabolic diseases have been linked to the disruption of circadian rhythms in night shift workers. Rotating night shift work is increasingly common in the working population worldwide. Hypothesis: We hypothesized that light therapy might help to normalize disrupted circadian rhythms and stabilize diurnal control of blood pressure and glucose tolerance in rotating night shift workers. Methods: We randomized 24 rotating night shift workers (mean age, 36±13 years, 7 males) who had spent a median of 6 years on rotating night shifts with a median of 6 night shifts/month to 12 weeks of light therapy (light during first half of each night shift and in the morning of off-work days) or no intervention and compared them with 12 daytime workers (37±11 years, 6 males). We measured oral glucose tolerance (OGTT), 24h blood pressure and arterial stiffness, and the circadian profiles of melatonin, cortisol, metanephrine and normetanephrine at baseline, after 12 weeks of intervention, and 12 weeks after the end of intervention. Results: At baseline, fewer night shift workers showed dipper status of blood pressure as compared to daytime workers (21% vs. 55%; p<0.001). After 12 weeks of light therapy, there was a highly significant increase in the proportion of dippers (to 42%; p<0.0001). We also observed a significant decrease in serum glucose during OGTT in the light therapy group (-22%; p<0.05), with no change in serum insulin. Whilst circadian profiles of melatonin and cortisol were unchanged, there was a significant reduction in nighttime plasma metanephrine and normetanephrine levels in the light therapy group (p<0.01). Conclusions: Chronotherapeutic light therapy significantly improves diurnal blood pressure control and glucose tolerance in rotating night shift workers. This effect is unrelated to mechanisms traditionally linked to the circadian clock like melatonin and cortisol, but it is paralleled by reduced catecholamine levels. Our data suggest that chronotherapeutic light therapy may improve the adjustment to atypical working hours in rotating night shift workers, thereby reducing stress and improving cardiometabolic function.

296 Sex differences in sleep and wakefulness of police officers working shifts: evidence from a field study

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A118-A118
Author(s):  
Gabriela Caetano ◽  
Laura Kervezee ◽  
Fernando Gonzales-Aste ◽  
Philippe Boudreau ◽  
Diane Boivin
Keyword(s):  
Sex Differences ◽  
Circadian Rhythms ◽  
Shift Work ◽  
Police Officers ◽  
Field Studies ◽  
Time Of Day ◽  
Cycle Phase ◽  
Shift Workers ◽  
Work Related ◽  
Time Awake

Abstract Introduction National reports of work-related injuries found the excess risk of work injury attributed to shift work to be significantly higher among women. The Working Time Society (WTS) concluded that male sex is one of the few factors that is “consistently associated with perceived or actual shift work tolerance”. However, it is unclear if physiological parameters are involved. Laboratory-controlled studies report sex differences in circadian rhythms (body temperature, melatonin). In sleep deprivation protocols, alertness and cognitive performances were affected by sex, menstrual cycle phase and hormonal contraceptives [HC] use. Nevertheless, field studies that compare male and female shift workers are scarce. Methods An observational study including 76 police officers working on patrol: 56 males and 20 females (11 using [HC], 6 not using [non-HC] and 3 with unknown use of hormonal contraception) aged 32.0 ± 5.3 years. Participants were followed throughout a month-long work cycle (1,457 morning, evening, night, or other shifts, plus rest days). They filled out time-stamped questionnaires (Samn-Perelli, KSS, Visual Analogue Scales, ~5/day; sleep and work-related information, ~1–2/day), completed 5-min Psychomotor Vigilance Tasks (PVT, ~2/day), and wore an actigraph to collect activity data. Linear mixed-effects models were used to analyze the effects of group, time awake and time-of-day on fatigue, sleepiness, alertness, mood and PVT measures. Results Self-reported measures and psychomotor performance significantly varied with time awake and time-of-day. Fatigue and sleepiness levels were significantly higher among female compared to male police officers, both with time awake and across the 24-h day. These variations were similar between non-HC females and the other groups. Compared to males, HC females were more fatigued and less alert, both with time awake and across the 24-h day, and sleepier with time awake. Having children at home did not explain these differences. Conclusion The results of this study expand our knowledge on the sex differences in the sleep and circadian physiology and demonstrate a critical effect of HC on women fatigue, sleepiness and alertness when working shifts. Sex and hormonal parameters must be considered in occupational medicine as well as in future laboratory and field studies on shift workers and circadian rhythms. Support (if any) IRSST, FRQS.

scholarly journals Personality Traits and Insomnia Symptoms in Shift Workers

2021 ◽  
Vol 12 ◽  
Author(s):  
Brigitte Holzinger ◽  
Lucille Mayer ◽  
Gerhard Klösch
Keyword(s):  
Sleep Quality ◽  
Personality Traits ◽  
Sleep Duration ◽  
Total Sleep Time ◽  
Sleep Time ◽  
Work Schedule ◽  
Shift Workers ◽  
Time In Bed ◽  
Shift Schedules ◽  
Insomnia Symptoms

The discrepancy between natural sleep-wake rhythm and actual sleep times in shift workers can cause sleep loss and negative daytime consequences. Irregular shift schedules do not follow a fixed structure and change frequently, which makes them particularly harmful and makes affected individuals more susceptible to insomnia. The present study compares insomnia symptoms of non-shift workers, regular shift workers, and irregular shift workers and takes into account the moderating role of the Big Five personality traits and levels of perfectionism. Employees of an Austrian railway company completed an online survey assessing shift schedules, sleep quality and duration, daytime sleepiness, and personality traits. A total of 305 participants, of whom 111 were non-shift workers, 60 regular shift workers, and 134 irregular shift workers, made up the final sample. Irregular shift workers achieved significantly worse scores than one or both of the other groups in time in bed, total sleep time, sleep efficiency, sleep duration, sleep quality, sleep latency, and the number of awakenings. However, the values of the irregular shifts workers are still in the average range and do not indicate clinical insomnia. Participants working regular shifts reported the best sleep quality and longest sleep duration and showed the least nocturnal awakenings, possibly due to higher conscientiousness- and lower neuroticism scores in this group. Agreeableness increased the effect of work schedule on total sleep time while decreasing its effect on the amount of sleep medication taken. Perfectionism increased the effect of work schedule on time in bed and total sleep time. Generalization of results is limited due to the high percentage of males in the sample and using self-report measures only.

scholarly journals 0409 The Efficacy of Afternoon-Evening Sleep Following Night Shifts on Sleep and Alertness in Nurses with Rotating Shift Work Schedule: Real World Data

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A156-A157
Author(s):  
J Kim ◽  
S Han ◽  
S Kim ◽  
J Duffy
Keyword(s):  
Sleep Duration ◽  
Shift Work ◽  
Total Sleep Time ◽  
Sleep Time ◽  
Hospital Nurses ◽  
Sleep Timing ◽  
Time In Bed ◽  
Shift Schedules ◽  
Sleep Schedule ◽  
Night Shifts

Abstract Introduction The aim of this study was to investigate the efficacy of changing sleep timing to afternoon-evening following nightshifts in hospital nurses with three rapid rotating shift schedules. Methods Hospital nurses with three rotating shift schedules were enrolled for a 1-month pre-intervention and a 1-month intervention study. During the Intervention, sleep timing following nightshifts was directed to afternoon-evening sleep for 8h time-in-bed (TIB) after 1 PM, and ad-lib sleep schedule for other shifts. Baseline and follow-up evaluation included sleep schedule, sleep duration, Epworth sleepiness scale (ESS), insomnia severity index (ISI) for each shift, Beck depression inventory (BDI), and Beck anxiety inventory (BAI). Sleep was assessed by sleep diary and actigraphy. Alertness during the night shift was evaluated using the Karolinska sleepiness scale (KSS) in the beginning and at the end of the shift by texts sent to their cell phones. The participants were asked to give feedback and a willingness to continue this intervention. Results A total of 26 subjects (30.7±8.5years, 25 female) finished the study among 29 nurses who participated in the study. The shift work was 6.5±8.0years. The mean morningness-eveningness scale was 42.1±8.0(31-62). TIB following nightshifts were 379.9±91.2 and 478.4±48.7 min for preintervention and intervention, respectively (p=0.001). Total sleep time (TST) was 328.0±91.0 vs. 361.0±70.4min, respectively following nightshifts (p=0.187, Cohen’s drm = 0.467). BDI, BAI, ESS, and ISI were significantly improved after the intervention. 60.7% and 49% of the participants reported improved alertness, and work efficiency during the nightshift. 17.9% and 42.9% of the participants reported increased sleep duration, and improved sleep quality after nightshift, respectively. Only eight participants were willing to continue the afternoon-evening sleep schedule following night shifts. KSS was not different between pre-intervention and intervention. Conclusion The afternoon-evening sleep schedule modestly increased total sleep time following nightshift. The overall mood, sleepiness and insomnia scale improved after the intervention although the alertness assessed by KSS failed to show the difference. The individual difference should be considered for applying afternoon-evening sleep for rapid rotating shift schedules. Support 2018 Research award grants from the Korean sleep research society and NRF-2019R1A2C1090643 funded by the Korean national research foundation

Jet Lag, Shift Work, and Maladaption

Physiology ◽  
1986 ◽  
Vol 1 (5) ◽  
pp. 156-160 ◽  
Author(s):  
MC Moore-Ede
Keyword(s):  
Phase Shift ◽  
Shift Work ◽  
Circadian System ◽  
Multiple Time ◽  
Jet Lag ◽  
Work Schedules ◽  
Human Species ◽  
Time Zones ◽  
Rotating Shift Work ◽  
Circadian Pacemakers

The circadian pacemakers, which time the approximately 24-h cycle of sleep and wakefulness, resynchronize only slowly after an abrupt phase shift in environmental time cues. Consequently, we are not well equipped to cope with jet travel across multiple time zones or with rotating shift work schedules, neither of which was in the evolutionary experience of the human species. Recent studies of the human circadian system suggest some strategies to minimize the ill effects of jet lag and shift work.

Diurnal and Seasonal Variations in Industrial Fatigue of Shift Workers

1976 ◽  
Vol 20 (22) ◽  
pp. 515-518
Author(s):  
Andrzej Ogiński ◽  
Lucyna Koźlakowska-Swigoń ◽  
Janusz Pokorski
Keyword(s):  
Heart Rate ◽  
Shift Work ◽  
Pulse Rate ◽  
Seasonal Variations ◽  
Shift Workers ◽  
Seasonal Factor ◽  
Analysis Of Results ◽  
Fatigue Estimation ◽  
Continuous Work ◽  
Night Shifts

The interview was carried out with 1664 steelworkers in the aim of obtaining their opinion on subjective fatigue accompanying the work on morning, afternoon and night shifts. Warm and cold seasons of the year were treated separately. Continuous work observations and telemetric heart rate registration were conducted at some workplaces. Analysis of results exhibited a great differentiation of fatigue estimation on particular shifts. Influence of the seasonal factor was found to be very important both in the reported feeling of fatigue as in changes of the pulse rate. Conclusions concern the ergonomic approach to fatigue problems in shift work.

scholarly journals Impacts of shift work: A study in textile companies in Portugal

2017 ◽  
Vol 1 (1) ◽  
pp. 69-78
Author(s):  
I. S. Silva ◽  
J. Keating ◽  
D. Costa
Keyword(s):  
Shift Work ◽  
Social Life ◽  
Sleep Disturbances ◽  
Night Shift ◽  
The Other ◽  
Work Schedules ◽  
Textile Workers ◽  
Shift Workers ◽  
Work Shifts ◽  
Morning Shift

Shift work, especially if it involves night work and/or weekend work, may represent disadvantages for workers and their families at the level of family, social life, and health. The present study evaluates the impacts of three work shifts (morning, afternoon and night) on sleep, family and social life as well as satisfaction with work schedules. In total, 373 Portuguese textile workers participated in this study; all were men. The results indicated that night shift workers had greater sleep disturbances and less satisfaction with their work schedules. On the other hand, morning shift workers were most satisfied with family and social life in association with their work schedules. Based on the results, implications of the practice have been reflected.

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