Variations of cortisol, fatigue and sleep disturbances in sound engineers: effect of job task and fast backward-rotating shifts

The aim was to study the effect of job task and fast backward-rotating shifts on the time-of-day variations of cortisol, fatigue, and sleep disturbances in broadcasting sound engineers. The concentration of saliva cortisol and ratings of stress, sleepiness, and fatigue were followed at 3-hour intervals during the fast backward-rotating shifts in 26 sound engineers: 14 subjects from control rooms, aged 45.1 +/- 7.3 years, and 12 subjects working in direct transmissions, aged 51.7 +/- 6.0 years. Saliva cortisol was assessed using an radioimmunology kit. The participants reported for stress symptoms after the shifts and filled a sleep diary. The effects of job task, shift, and time-of-day were analyzed by tests of between-subjects effects (SPSS). Cortisol retained the typical diurnal pattern with a highly significant effect of the shift. The job task and the shift interacted significantly. Higher cortisol values during the morning and night shifts in engineers working in direct transmissions were found. Their stress ratings were also higher, as well as the ratings of sleepiness and fatigue. The quality of sleep was worse in engineers working in direct transmissions. In conclusion, our data indicate that stress and fast backward-rotating shifts in sound engineers working in direct transmissions affect physiological stress markers such as cortisol and increase sleepiness, fatigue, and sleep problems.     

Stress and fatigue in sound engineers: the effect of broadcasting in a life show and shift work

The aim was to study the time-of-day variations of cortisol, fatigue and sleep disturbances in sound engineers in relation to job task and shift work. The concentration of saliva cortisol and feeling of stress, sleepiness and fatigue were followed at three hour intervals in 21 sound engineers: 13 sound engineers, aged 45.1 +/- 7.3 years, broadcasting in a life show during fast forward rotating shifts and 8 sound engineers, aged 47.1 +/- 9.8 years, making records in a studio during fast rotating day shifts. Cortisol concentration was assessed in saliva with radioimmunological kits. The participants reported for stress symptoms during the shifts and filled sleep diary. The data were analyzed by tests of between-subjects effects (SPSS). A trend for higher cortisol was found with the group broadcasting in a life show. The sound engineers broadcasting in a life show reported higher scores of stress, sleepiness and fatigue, but no significant differences concerning the sleep disturbances between the groups were found. In conclusion our data show moderate level of stress and fatigue with the studied sound engineers, higher with the subjects broadcasting in a life show. The quality of sleep showed no significant differences between the studied groups, an indication that the sound engineers were able to tolerate the fast forward rotating shifts.     

Different levels of work-related stress and the effects on sleep, fatigue and cortisol

OBJECTIVES: The aim of the study was to relate different levels of work stress to measures of sleep and the diurnal pattern of salivary cortisol and subjective sleepiness. METHODS: Thirty-four white-collar workers participated under two different conditions. One workweek with a relatively high stress level (H) and one with a lower stress level (L) as measured through self-rated stress during workdays. The workers wore activity monitors, filled out a sleep diary, gave saliva samples (for cortisol), and rated their sleepiness and stress during one workday and one free day. RESULTS: During the week with stress the number of workhours increased and total sleep time decreased. Sleepiness showed a significant interaction between weeks and time of day, with particularly high levels towards the evenings of the stress week. Cortisol also showed a significant interaction, with a more flattened pattern, probably due to increased evening levels during the stress week. Stress (restlessness) at bedtime was significantly increased during the stress week. CONCLUSIONS: The results demonstrate that a workweek with a high workload and much stress increases sleepiness and workhours, impairs sleep, and affects the pattern of diurnal cortisol secretion.     

Effects of diurnal and seasonal sleep deficiency on work effort and fatigue of shift workers

Summary This study was designed to assess and compare the quantity and quality of sleep of morning, afternoon, and night shift workers during the winter and summer seasons, and to evaluate the effects of sleep deficiency on the work effort and fatigue of the workers. The subjects studied consisted of a sample of 150 textile workers, working on a monthly rotating 3-shift system: morning shift (06.00–11.00 and 14.00–17.00) afternoon shift (11.00–14.00 and 17.00–22.00), and night shift (22.00–06.00). Information concerning quantity and quality of sleep were registered daily over a week for every subject. The Ratings of Perceived Effort scale and the Feeling and Symptoms of Fatigue scale were used to collect information about feeling of effort and fatigue of the subjects. The results showed that the duration of sleep length is longest in the afternoon and shortest in the night shift both during summer and winter. The amount of sleep is shorter during summer during all three shifts. The workers spent more effort and felt more fatigued during summer than winter. The shift workers, particularly of the tropical region, like Bangladesh, seem to be worst affected in terms of quantity and quality of sleep, health and well-being due to extremely high temperature (30–45° Celsius) during summer than winter (5–25° Celsius). The workers think that the problems of shift work could be minimized by improving the quality of working and living conditions, reducing cycle of rotation, shortening working day and closing night shift during peak summer.     

Elevated salivary cortisol levels as a result of sleep deprivation in a shift worker

BACKGROUND: This paper reports a case from a group of 63 shift-workers for whom adaptation to shift-work was evaluated through measurement of salivary cortisol levels. METHODS: Workers' saliva was sampled and cortisol levels measured at intervals of 2 h during morning, evening and night shifts. RESULTS: For one subject among the 63, very high values of cortisol (an approximately 6-fold increase) were observed for the morning (M) shift, but with normal values found for evening (E) and night (N) shifts. Individual mean and peak cortisol values were 48.4 and 67.8 nmol/l against group mean and peak cortisol values of 8.9 and 11.0 nmol/l. Retrospective questioning showed that this subject was healthy and there were no indicators of long-term stress. CONCLUSION: This cortisol rise was deduced to be caused by sleep deprivation as a result of rapidly rotating shift patterns.     

The effect of work shift and sleep duration on various aspects of police officers' health

Police officers are prone to cardiovascular disease, overweight, and obesity. Because night-shift work affects sleep, a modifiable risk factor linked to chronic disease, the researchers explored the relationship among shift work, sleep, and wellness for police officers. Sleep, C-reactive protein (CRP) levels, stress, fatigue, and body mass index were used to compare officers who worked primarily day shifts to those who worked primarily evening or night shifts, and officers who slept less than 6 hours per day to those who slept at least 6 hours per day. A cross-sectional study of 85 male officers, 20 to 63 years old, was completed at three Midwestern police departments. The Pittsburgh Sleep Quality Index was used to assess sleep. A questionnaire was used to collect officer demographics and work hours. Other measurements included serum CRP, height, weight, perceived stress, and vital exhaustion. The relative risk of sleeping less than 6 hours per day for officers who primarily worked non-day shifts, compared to those who worked day shifts, was 14.27 (95% confidence interval [CI], 1.98-102.95, p < .001), and the relative risk of overall poor sleep quality for officers who slept less than 6 hours per day, compared to those who slept more hours, was 2.44 (95% CI, 1.15-5.20, p = .027). CRP was not associated with shift or sleep duration, even when adjusted for officers' ages.     

The effect of symptom frequency on the fatigue and sleep quality of adolescent cancer patients

This study was performed in order to determine the effects of frequency of symptoms of adolescents with cancer on sleeping quality and fatigue. In order to collect the data, the Children Information Form, Symptom Evaluation Form, the Fatigue Assessment Scale for Pediatric Oncology Patients Between the Ages of 13 and 18 years, and the Pittsburgh Sleep Quality Index (PSQI) were used. Percentage calculations, mean, one-way variance analysis, and advanced analysis such as Scheffe tests were used. p < 0.05 was accepted as the significance. As the symptom frequencies increased in adolescents, total fatigue scale and its subdimension scores decreased and sleep quality total scores increased. There was a low relationship between the scores of symptom frequency and fatigue scale, there was a moderate association between scores of symptom frequency and the sleep quality scale scores, and there was a high relationship between the scores of fatigue (p < 0.001). As the symptom frequencies increased in adolescents, total fatigue scale and its subdimension scores decreased and sleep quality total scores increased.     

倒班制员工的自我效能感与睡眠质量、心理健康的关系

目的探讨倒班制对员工自我效能感、睡眠质量和心理健康的影响,以及员工自我效能感与睡眠质量和心理健康的关系。方法应用自我效能感问卷、睡眠质量问卷和症状自评量表,对某市交通部门100名员工进行问卷调查。结果倒班制员工表现出较高的躯体化、恐怖和精神病性症状(P<0.05),以及较低的睡眠质量和自我效能感(P<0.001);倒班制员工自我效能感与躯体化、人际关系敏感、焦虑、敌对、睡眠质量呈显著负相关(P<0.05)。结论倒班制降低了企业员工的心理健康、睡眠质量和自我效能感。     

Melatonin, sleep, and shift work adaptation

BACKGROUND: Night work is associated with disrupted circadian rhythms, fatigue, accidents, and chronic disease. Melatonin secretion helps regulate sleep and circadian rhythms. OBJECTIVE: Melatonin, sleep disturbances, and symptoms (sleep, fatigue, mental) were compared among workers on permanent day, swing, and night shifts. METHODS: Urinary 6-hydroxymelatonin sulfate (6-OHMS) was measured in postwork and postsleep samples. Disrupted circadian melatonin production was evaluated using the sleep:work 6-OHMS ratio. Wrist actigraphy characterized light exposures and sleep characteristics. RESULTS: Night workers had altered melatonin, disrupted sleep, and elevated symptom prevalence. Subjects grouped by their sleep:work 6-OHMS ratio rather than shift had even greater symptom prevalence. Risks for two or more symptoms were 3.5 to 8 times greater among workers with sleep:work ratios < or =1 compared to those with ratios >1. CONCLUSIONS: This ratio may help identify workers at increased risk for accidents or injuries.     

The acute effects of working time patterns on fatigue and sleep quality using daily measurements of 6195 observations among 223 shift workers

Objectives:This study aimed to estimate acute effects of roster characteristics on fatigue and sleep quality and investigated whether these effects differed by individual characteristics.Methods:Using an ecological measurement assessment survey, fatigue and sleep quality were daily measured among 223 shift workers for up to eight weeks. A questionnaire assessed baseline characteristics, and roster data were retrieved from the company registers to determine roster parameters. The effects between each shift parameter on fatigue and sleep quality were estimated with random- and fixed-effects models.Results:Compared to day shifts, night shifts were related to fatigue [β=0.22; 95% confidence interval (CI) 0.05–0.39] and poorer sleep quality (β =0.64; 95% CI 0.47–0.80), and more successive night shifts with more fatigue (up to β=0.68; 95% CI 0.49–0.87 for ≥2 nights). Fatigue was increased after a quick return (<11 hours) (β=1.94; 95% CI 1.57–2.31) or 11–16 hours (β=0.43; 95% CI 0.26–0.61) compared to >16 hours between shifts. Compared to forward rotation, stable (β=0.22; 95% CI 0.01–0.43) and backward rotation (β=0.49; 95% CI 0.23–0.74) were also associated with more fatigue. Workers with a morning or intermediate chronotype had poorer sleep quality after a night shift, while workers with poor health reported poor sleep quality as well as more fatigue after a night shift.Conclusions:To alleviate acute effects of shift work on fatigue, shift schedules should be optimized by ensuring more time to recover and rotate forwards.     

Studies on fatigue and shift work in nurses]

Effects of shift work on physiological parameters and autonomic nervous-adrenal system were studied on six hospital nurses. Their body temperature, heart rate, blood pressure, fluctuation in ECG R-R intervals, serum catecholamines and cortisol, and subjective fatigue ratings before and after day, evening and night shift were determined. Furthermore, mean heart rates, walk steps, estimated energy expenditure, and urinary catecholamine excretion were determined three times for eight hours each during each shift work day. The following results were obtained: 1) No significant changes were detected in the physiological parameters before and after each shift work, except for elevation in plasma adrenaline level after night shift. 2) Heart rate, blood pressure and subjective fatigue rating tended to be higher, though not significantly, at the beginning of night shift, when compared with the data obtained on the some time of day, i.e., at the end of evening shift. 3) On the other hand, the plasma cortisol level tended to be suppressed after night shift, suggesting that even one night shift work may change the circadian rhythm of plasma cortisol. 4) Statistical analyses showed that in contrast to day and evening shift, in night shift there was no significant positive correlation between eight-hour walk steps, and eight-hour mean heart rate and urinary adrenaline excretion, suggesting an altered circadian rhythm in heart rate and urinary adrenaline excretion and also a possible additional psychological load in night shift. These results suggest that even one night shift work could modulate the autonomic nervous-adrenal activity of hospital nurses, compared with day or evening shift, and indicate that it is necessary to lengthen the time interval before and after night shift work.     

Disturbed sleep and fatigue in occupational burnout

OBJECTIVES: The purpose of this study was to investigate sleep with polysomnography and self-ratings and the diurnal pattern of sleepiness and fatigue in a group suffering from severe occupational burnout. METHOD: Twelve white-collar workers on long-term sick leave (>3 months) and 12 healthy controls with high and low scores on the Shirom Melamed Burnout Questionnaire (SMBQ) were included. A 1-night polysomnographic recording (after habituation) was carried out at home, and sleepiness and mental fatigue were rated at different times of the day for weekdays and the weekend. Precipitating factors at the time of the illness at work and real life were considered, and different dimensions of occupational fatigue were described. A repeated-measures analysis of variance using two or three within group factors was used to analyze the data. RESULTS: The main polysomnographic findings were more arousals and sleep fragmentation, more wake time and stage-1 sleep, lower sleep efficiency, less slow wave sleep and rapid eye movement sleep, and a lower delta power density in non-rapid eye movement sleep in the burnout group. The burnout patients showed pronounced sleepiness and mental fatigue at most times of the day for weekdays without reduction during weekends. The precipitating factor was occupational stress (psychiatric interview), and work stress indicators were increased. CONCLUSIONS: Occupational burnout is characterized by impaired sleep. It is suggested that impaired sleep may play a role in the development of fatigue or exhaustion in burnout.     

Effects of shift rotation and the flexibility of a shift system on daytime alertness and cardiovascular risk factors

OBJECTIVES: A controlled intervention study was conducted to evaluate the effects of two changes in shift characteristics on alertness and cardiovascular risk factors: a change in shift rotation (direction and speed) and a change in the flexibility of the shift system. METHODS: Altogether 84 male workers currently working in a backward-rotating shift system volunteered for the study. A total of 40 men changed to a rapidly forward-rotating shift system, 22 changed to a more flexible shift system, and 22 remained with the old shift system. Health effects were studied with the use of clinical measurements, blood tests, and questionnaires before and after the shift changes. Analyses of variance were used with repeated measures to study associations of cardiovascular risk factors and daytime sleepiness according to the change in shift systems. RESULTS: The mean number of days on which the workers reported sleepiness decreased in the group with the forward-rotating shift system when compared with that of the group on the old shift system (from 2.9 to 2.1 days/week, P=0.02). Systolic blood pressure decreased (from 142 to 136 mm Hg, P=0.049), and heart rate showed a declining trend (from 66 to 60 beats/minute, P=0.06) in the flexible shift system when the three groups were compared. CONCLUSIONS: The study indicates that a faster speed, together with a change to the forward direction, in shift rotation alleviates daytime sleepiness. Combining individual flexibility with company-based flexibility in a shift system may have favorable effects on shift workers' blood pressure.     

护士职业倦怠与唾液中皮质醇水平的相关性研究

目的探讨护士职业倦怠与唾液中皮质醇水平的相关性。方法采用分层-随机-整群的抽样方法,在某市中心医院32个病区抽取10个病区符合纳入标准的在职护士130人,采用职业倦怠调查表(MBI)对其进行测试,并于早晨8:00收集唾液标本,采用酶联免疫吸附测定法(ELISA)分析唾液中皮质醇浓度。结果调查对象职业倦怠状况处于中等偏高状态;皮质醇浓度在情绪枯竭和去人格化倾向方面随倦怠水平增高而升高,而在个人成就感方面则降低,差异有统计学意义(P<0.05)。结论护士职业倦怠会引起唾液中皮质醇分泌增加,医院管理者应了解职业倦怠对个体的影响,重视护士的身心健康;唾液中皮质醇水平测试分析,使职业倦怠研究更加量化、科学。     

Influence of overtime work, sleep duration, and perceived job characteristics on the physical and mental status of software engineers

To investigate the impact of overtime work, sleep duration, and perceived job characteristics on physical and mental status, a cross-sectional study was conducted on 377 workers (average age; 28 years old) in an information-technology (IT) company, engaged in consultation, system integration solution, and data management relevant to IT system. The psychophysical outcomes of overtime work were assessed using the Hamilton Depression Scale (HDS), Profile of Mood Status (POMS), major physical symptoms, and overtime work data for the preceding three-months. Sleep duration was directly asked by a physician. A job strain index was defined as the ratio of job-demands to job-control scores evaluated using the Job Content Questionnaire (JCQ). In a univariate analysis, overtime work was significantly related with HDS scores, POMS anger-hostility scores, and the total physical symptom count in both sexes (all p < 0.05), but not in multiple regression models, after controlling for sleep duration and the job strain index. Sleep duration was negatively related to the symptom count in men and to POMS tension-anxiety scores in women (both p < 0.05); the job strain index was positively related to POMS anger-hostility scores in both sexes and to HDS scores and POMS tension-anxiety scores in men (all p < 0.05). Although overtime work was associated with physical and mental complaints, sleep duration and the job strain index seemed to be better indicators for physical and mental distress in overloaded workers.     

The effect of furniture arrangement on movement,on-task behavior,and sound in an early childhood setting

The effects of structured furniture arrangement in an early childhood classroom were compared with an open arrangement using movement, on-task behavior and sound levels as the dependent variables. A single subject reversal design construing the classroom with fourteen five-year-olds as the single subject was used. More movement, less on-task behavior, and higher sound levels were predicted in the open arrangement than in the structured condition. The results of observations during free play did not support the predictions.Maine Agricultural Experiment Station No. 1135. An earlier version of this paper was presented at the annual meeting of the New England Educational Research Organization, Rockland, ME, April, 1986.     

The mediating role of sleep,physical activity,and diet in the association between shift work and respiratory infections

Objectives:Shift work may be associated with an increased incidence of respiratory infections. However, underlying mechanisms are unclear. Therefore, our aim was to examine the mediating role of sleep, physical activity, and diet in the association between shift work and respiratory infections.Methods:This prospective cohort study included 396 shift and non-shift workers employed in hospitals. At baseline, sleep duration and physical activity were measured using actigraphy and sleep/activity diaries, sleep quality was reported, and frequency of meal and snack consumption was measured using food diaries. In the following six months, participants used a smartphone application to report their influenza-like illness/acute respiratory infection (ILI/ARI) symptoms daily. Mediation analysis of sleep, physical activity, and diet as potential mediators of the effect of shift work on ILI/ARI incidence rate was performed using structural equation modeling with negative binomial and logistic regression.Results:Shift workers had a 23% [incidence rate ratio (IRR) 1.23, 95% CI 1.01–1.49] higher incidence rate of ILI/ARI than non-shift workers. After adding the potential mediators to the model, this reduced to 15% (IRR 1.15, 95% CI 0.94–1.40). The largest mediating (ie, indirect) effect was found for poor sleep quality, with shift workers having 29% more ILI/ARI episodes via the pathway of poorer sleep quality (IRR 1.29, 95% CI 1.02–1.95).Conclusions:Compared to non-shift workers, shift workers had a higher incidence rate of ILI/ARI that was partly mediated by poorer sleep quality. Therefore, it may be relevant for future research to focus on perceived sleep quality as an underlying mechanism in the relation between shift work and increased infection susceptibility.