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Wang Y, Chen H, Li X, Zhao X, Yang X, Zhang H, Zhang J, Liu J. Person-centered exploration of work-related stress patterns, predictors, and their association with subhealth in midwives: A cross-sectional study. Women Birth 2024; 37:101655. [PMID: 39024982 DOI: 10.1016/j.wombi.2024.101655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 06/27/2024] [Accepted: 07/04/2024] [Indexed: 07/20/2024]
Abstract
BACKGROUND Midwives experience elevated levels of work-related stress. However, there is limited understanding of the patterns of this stress, its sociodemographic and work-related determinants, and its association with sub-health. METHOD This multi-center cross-sectional study, conducted in 21 hospitals in Zhuhai City, Guangdong Province, China, involved 300 midwives. Work-related stress levels in midwives were evaluated using the Chinese version of the Nursing Stress Scale, while social, physical and mental sub-health status was measured with the Sub-Health Measurement Scale. Utilizing latent profile analysis, the study aimed to categorize midwives into homogeneous profiles based on patterns of work-related stress. RESULTS Among the 300 midwives examined, three distinct profiles were identified: profile 1 (n=57, 19 %), characterized by low work-related stress; profile 2 (n=149, 50 %), representing the moderate work-related stress class; and profile 3 (n=94, 31 %), indicative of high work-related stress. Midwives in the high work-related stress profile tended to be younger, with lower monthly income, lower professional titles, and a higher likelihood of night shift work (all P<0.01). Significant and noteworthy trends were observed in sociodemographic characteristics (age, monthly income, and professional title) and work-related characteristics (night shift status). After controlling for confounders, the work-related stress profile demonstrated a negative association with social, physical and mental sub-health status. CONCLUSION This study highlights integrating stress domains and adopting a person-centered approach to examine midwives' work-related stress. Identifying predictors of profile membership and their relationship with sub-health can inform tailored interventions to reduce stress and improve midwives' well-being.
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Affiliation(s)
- Yao Wang
- Postnatal Care Center (Department of Postpartum Rehabilitation), Zhuhai Center for Maternal and Child Health Care, Zhuhai, Guangdong, China; Faculty of Medicine, Macau University of Science and Technology, Macao Special Administrative Region of China
| | - Hengying Chen
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiuzhen Li
- Department of Obstetrics, Zhuhai Center for Maternal and Child Health Care, Zhuhai, Guangdong, China
| | - Xiangfeng Zhao
- Department of Nursing, Zhuhai Center for Maternal and Child Health Care, Zhuhai, Guangdong, China
| | - Xiaoyue Yang
- Department of Nursing, the Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Hongzhong Zhang
- Zhuhai Center for Maternal and Child Health Care, Zhuhai, Guangdong, China
| | - Jianduan Zhang
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Junrong Liu
- School of Marxism, Guangzhou Medical University, Guangzhou, China.
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Saner NJ, Lee MJC, Pitchford NW, Broatch JR, Roach GD, Bishop DJ, Bartlett JD. The effect of sleep restriction, with or without high-intensity interval exercise, on behavioural alertness and mood state in young healthy males. J Sleep Res 2024; 33:e13987. [PMID: 37434366 DOI: 10.1111/jsr.13987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/01/2023] [Accepted: 06/20/2023] [Indexed: 07/13/2023]
Abstract
Mood state and alertness are negatively affected by sleep loss, and can be positively influenced by exercise. However, the potential mitigating effects of exercise on sleep-loss-induced changes in mood state and alertness have not been studied comprehensively. Twenty-four healthy young males were matched into one of three, 5-night sleep interventions: normal sleep (NS; total sleep time (TST) per night = 449 ± 22 min), sleep restriction (SR; TST = 230 ± 5 min), or sleep restriction and exercise (SR + EX; TST = 235 ± 5 min, plus three sessions of high-intensity interval exercise (HIIE)). Mood state was assessed using the profile of mood states (POMS) and a daily well-being questionnaire. Alertness was assessed using psychomotor vigilance testing (PVT). Following the intervention, POMS total mood disturbance scores significantly increased for both the SR and SR + EX groups, and were greater than the NS group (SR vs NS; 31.0 ± 10.7 A.U., [4.4-57.7 A.U.], p = 0.020; SR + EX vs NS; 38.6 ± 14.9 A.U., [11.1-66.1 A.U.], p = 0.004). The PVT reaction times increased in the SR (p = 0.049) and SR + EX groups (p = 0.033) and the daily well-being questionnaire revealed increased levels of fatigue in both groups (SR; p = 0.041, SR + EX; p = 0.026) during the intervention. Despite previously demonstrated physiological benefits of performing three sessions of HIIE during five nights of sleep restriction, the detriments to mood, wellness, and alertness were not mitigated by exercise in this study. Whether alternatively timed exercise sessions or other exercise protocols could promote more positive outcomes on these factors during sleep restriction requires further research.
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Affiliation(s)
- Nicholas J Saner
- Institute for Health and Sport (iHeS), College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Matthew J-C Lee
- Institute for Health and Sport (iHeS), College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Nathan W Pitchford
- School of Health Sciences, University of Tasmania, Launceston, Australia
| | - James R Broatch
- Institute for Health and Sport (iHeS), College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Greg D Roach
- Appleton Institute for Behavioural Science, Central Queensland University, Adelaide, Australia
| | - David J Bishop
- Institute for Health and Sport (iHeS), College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Jonathan D Bartlett
- Institute for Health and Sport (iHeS), College of Sport and Exercise Science, Victoria University, Melbourne, Australia
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Zimberg IZ, Ftouni S, Magee M, Ferguson SA, Lockley SW, Rajaratnam SMW, Sletten TL. Circadian adaptation to night shift work is associated with higher REM sleep duration. Sleep Health 2024; 10:S112-S120. [PMID: 37914630 DOI: 10.1016/j.sleh.2023.08.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 11/03/2023]
Abstract
OBJECTIVE To investigate the influence of the degree of circadian adaptation to night work on sleep architecture following night shift. METHODS Thirty four night workers (11 females; 33.8 ± 10.1years) completed a simulated night shift following 2-7 typical night shifts. Participants completed a laboratory-based simulated night shift (21:00-07:00 hours), followed by a recovery sleep opportunity (∼09:00-17:00 hours), recorded using polysomnography. Urinary 6-sulphatoxymelatonin (aMT6s) rhythm acrophase was used as a marker of circadian phase. Sleep duration and architecture were compared between individuals with aMT6s acrophase before (unadapted group, n = 22) or after (partially adapted group, n = 12) bedtime. RESULTS Bedtime occurred on average 2.16 hours before aMT6s acrophase in the partially adapted group and 3.91 hours after acrophase in the unadapted group. The partially adapted group had more sleep during the week before the simulated night than the unadapted group (6.47 ± 1.02 vs. 5.26 ± 1.48 hours, p = .02). After the simulated night shift, both groups had similar total sleep time (partially adapted: 6.68 ± 0.80 hours, unadapted: 6.63 ± 0.88 hours, p > .05). The partially adapted group had longer total rapid eye movement sleep duration than the unadapted group (106.79 ± 32.05 minutes vs. 77.90 ± 28.86 minutes, p = .01). After 5-hours, rapid eye movement sleep accumulation was higher in the partially adapted compared to the unadapted group (p = .02). Sleep latency and other stages were not affected by circadian adaptation. DISCUSSION Partial circadian adaptation to night shift was associated with longer rapid eye movement sleep duration during daytime sleep, highlighting the influence of entrainment between the sleep-wake cycle and the circadian pacemaker in night workers. The findings have important implications for sleep and subsequent alertness associated with shift work.
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Affiliation(s)
- Iona Z Zimberg
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Suzanne Ftouni
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michelle Magee
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, Goodwood, South Australia, Australia
| | - Steven W Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Shantha M W Rajaratnam
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia; Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Tracey L Sletten
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.
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4
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Kosmadopoulos A, Boudreau P, Kervezee L, Boivin DB. Circadian Adaptation of Melatonin and Cortisol in Police Officers Working Rotating Shifts. J Biol Rhythms 2024; 39:49-67. [PMID: 37750410 PMCID: PMC10785562 DOI: 10.1177/07487304231196280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Misalignment of behavior and circadian rhythms due to night work can impair sleep and waking function. While both simulated and field-based studies suggest that circadian adaptation to a nocturnal schedule is slow, the rates of adaptation in real-world shift-work conditions are still largely unknown. The aim of this study was to evaluate the extent of adaptation of 24-h rhythms with 6-sulfatoxymelatonin (aMT6s) and cortisol in police officers working rotating shifts, with a special attention to night shifts. A total of 76 police officers (20 women; aged 32 ± 5.4 years, mean ± SD) from the province of Quebec, Canada, participated in a field study during their 28- or 35-day work cycle. Urine samples were collected for ~32 h before a series of day, evening, and night shifts to assess circadian phase. Before day, evening, and night shifts, 60%-89% of officers were adapted to a day schedule based on aMT6 rhythms, and 71%-78% were adapted based on cortisol rhythms. To further quantify the rate of circadian adaptation to night shifts, initial and final phases were determined in a subset of 37 officers with suitable rhythms for both hormones before and after 3-8 consecutive shifts (median = 7). Data were analyzed with circular and linear mixed-effects models. After night shifts, 30% and 24% of officers were adapted to a night-oriented schedule for aMT6s and cortisol, respectively. Significantly larger phase-delay shifts (aMT6s: -7.3 ± 0.9 h; cortisol: -6.3 ± 0.8 h) were observed in police officers who adapted to night shifts than in non-adapted officers (aMT6s: 0.8 ± 0.9 h; cortisol: 0.2 ± 1.1 h). Consistent with prior research, our results from both urinary aMT6s and cortisol midpoints indicate that a large proportion of police officers remained in a state of circadian misalignment following a series of night shifts in dim-light working environments.
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Affiliation(s)
- Anastasi Kosmadopoulos
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
- Appleton Institute for Behavioural Sciences, Central Queensland University, Adelaide, South Australia, Australia
| | - Philippe Boudreau
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Laura Kervezee
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Diane B. Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
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5
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Sprajcer M, Dawson D, Kosmadopoulos A, Sach EJ, Crowther ME, Sargent C, Roach GD. How Tired is Too Tired to Drive? A Systematic Review Assessing the Use of Prior Sleep Duration to Detect Driving Impairment. Nat Sci Sleep 2023; 15:175-206. [PMID: 37038440 PMCID: PMC10082604 DOI: 10.2147/nss.s392441] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/03/2023] [Indexed: 04/12/2023] Open
Abstract
Driver fatigue is a contributory factor in approximately 20% of vehicle crashes. While other causal factors (eg, drink-driving) have decreased in recent decades due to increased public education strategies and punitive measures, similar decreases have not been seen in fatigue-related crashes. Fatigued driving could be managed in a similar way to drink-driving, with an established point (ie, amount of prior sleep) after which drivers are "deemed impaired". This systematic review aimed to provide an evidence-base for the concept of deemed impairment and to identify how much prior sleep may be required to drive safely. Four online databases were searched (PubMed, Web of Science, Scopus, Embase). Eligibility requirements included a) measurement of prior sleep duration and b) driving performance indicators (eg, lane deviation) and/or outcomes (eg, crash likelihood). After screening 1940 unique records, a total of 61 studies were included. Included studies were categorised as having experimental/quasi-experimental (n = 21), naturalistic (n = 3), longitudinal (n = 1), case-control (n = 11), or cross-sectional (n = 25) designs. Findings suggest that after either 6 or 7 hours of prior sleep, a modest level of impairment is generally seen compared with after ≥ 8 hours of prior sleep (ie, well rested), depending on the test used. Crash likelihood appears to be ~30% greater after 6 or 7 hours of prior sleep, as compared to individuals who are well rested. After one night of either 4 or 5 hours of sleep, there are large decrements to driving performance and approximately double the likelihood of a crash when compared with well-rested individuals. When considering the scientific evidence, it appears that there is a notable decrease in driving performance (and associated increase in crash likelihood) when less than 5h prior sleep is obtained. This is a critical first step in establishing community standards regarding the amount of sleep required to drive safely.
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Affiliation(s)
- Madeline Sprajcer
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
- Correspondence: Madeline Sprajcer, Central Queensland University, Appleton Institute, 44 Greenhill Road, Wayville, SA, 5034, Australia, Email
| | - Drew Dawson
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
| | - Anastasi Kosmadopoulos
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
| | - Edward J Sach
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
| | - Meagan E Crowther
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
| | - Charli Sargent
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
| | - Gregory D Roach
- Appleton Institute for Behavioural Sciences, Central Queensland University, Wayville, SA, Australia
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Jensen MA, Hansen ÅM, Nabe-Nielsen K, Garde AH, Kristiansen J. Heart rate variability during sleep after two, four and seven consecutive night shifts and recovery days: a cross-over intervention study. Int Arch Occup Environ Health 2022; 95:1443-1451. [PMID: 35916933 DOI: 10.1007/s00420-022-01873-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 02/17/2021] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Recovery after shift work is an important part reducing the health problems related to shift work. Heart rate variability (HRV) is an indicator of the balance between sympathetic and parasympathetic activity in the autonomic nervous system and can be used as a measure of recovery after night shifts. The aim of the study is to investigate autonomic recovery during sleep in response to night work in a crossover intervention study. METHODS Seventeen male police officers working in call centres in five different police district participated in the HRV measurements. The participants were exposed to three interventions: 2 + 2: two consecutive night shifts followed by two consecutive day recovery days; 4 + 4: four consecutive night shifts followed by four consecutive recovery days; 7 + 7: seven consecutive night shifts followed by seven consecutive recovery days. On the last day with night shift and the last recovery day in each intervention the participants underwent 24 h HRV recordings. We analysed HRV during sleep. The five 5-min intervals with the lowest heart rate during each sleep period were chosen for spectral analysis of the heart interbeat interval time series. The five 5-min intervals could occur at any time during sleep. RESULTS There were overall differences in HRV during sleep between days with night shifts and recovery days, primarily in parasympathetic activity. There was no difference in the lowest heart rate obtained, but the timing was different for the three interventions. The lowest heart rate after night shifts occurred 112 (SD 79) min, 174 (SD 115) min and 135 (SD 94) min after sleep onset for the 2 + 2 night shift, the 4 + 4 night shift and the 7 + 7 night shift, respectively. CONCLUSION Overall sleep-related autonomic recovery had higher parasympathetic modulation of cardiac rhythm on the 2 + 2 shift system compared to the 4 + 4 and 7 + 7 shift system.
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Affiliation(s)
| | - Åse Marie Hansen
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark.,National Research Centre for the Working Environment, Copenhagen, Denmark
| | | | - Anne Helene Garde
- National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Jesper Kristiansen
- National Research Centre for the Working Environment, Copenhagen, Denmark
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Pedersen TT, Sunde E, Wisor J, Mrdalj J, Pallesen S, Grønli J. Sleep Homeostasis and Night Work: A Polysomnographic Study of Daytime Sleep Following Three Consecutive Simulated Night Shifts. Nat Sci Sleep 2022; 14:243-254. [PMID: 35210891 PMCID: PMC8863345 DOI: 10.2147/nss.s339639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 12/04/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Millions of people work at times that overlap with the habitual time for sleep. Consequently, sleep often occurs during the day. Daytime sleep is, however, characterized by reduced sleep duration. Despite preserved time spent in deep NREM sleep (stage N3), daytime sleep is subjectively rated as less restorative. Knowledge on how night work influences homeostatic sleep pressure is limited. Therefore, we aimed to explore the effect of three consecutive simulated night shifts on daytime sleep and markers of sleep homeostasis. PATIENTS AND METHODS We performed continuous EEG, EMG and EOG recordings in the subjects' home setting for one nighttime sleep opportunity, and for the daytime sleep opportunities following three consecutive simulated night shifts. RESULTS For all daytime sleep opportunities, total sleep time was reduced compared to nighttime sleep. While time spent in stage N3 was preserved, sleep pressure at sleep onset, measured by slow wave activity (1-4 Hz), was higher than nighttime sleep and higher on day 3 than on day 1 and 2. Elevated EEG power during daytime sleep was sustained through 6 h of time in bed. Slow wave energy was not significantly different from nighttime sleep after 6 h, reflecting a less efficient relief of sleep pressure. CONCLUSION Adaptation to daytime sleep following three consecutive simulated night shifts is limited. The increased homeostatic response and continuation of sleep pressure relief even after 6 h of sleep, are assumed to reflect a challenge for appropriate homeostatic reduction to occur.
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Affiliation(s)
- Torhild T Pedersen
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, Bergen, Norway
| | - Erlend Sunde
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway
| | - Jonathan Wisor
- Sleep and Performance Research Center and Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Jelena Mrdalj
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, Bergen, Norway
| | - Ståle Pallesen
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway.,Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway.,Optentia Research Focus Area, North-West University, Vanderbijlpark, South Africa
| | - Janne Grønli
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, Bergen, Norway
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Boivin DB, Boudreau P, Kosmadopoulos A. Disturbance of the Circadian System in Shift Work and Its Health Impact. J Biol Rhythms 2021; 37:3-28. [PMID: 34969316 PMCID: PMC8832572 DOI: 10.1177/07487304211064218] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The various non-standard schedules required of shift workers force abrupt changes in the timing of sleep and light-dark exposure. These changes result in disturbances of the endogenous circadian system and its misalignment with the environment. Simulated night-shift experiments and field-based studies with shift workers both indicate that the circadian system is resistant to adaptation from a day- to a night-oriented schedule, as determined by a lack of substantial phase shifts over multiple days in centrally controlled rhythms, such as those of melatonin and cortisol. There is evidence that disruption of the circadian system caused by night-shift work results not only in a misalignment between the circadian system and the external light-dark cycle, but also in a state of internal desynchronization between various levels of the circadian system. This is the case between rhythms controlled by the central circadian pacemaker and clock genes expression in tissues such as peripheral blood mononuclear cells, hair follicle cells, and oral mucosa cells. The disruptive effects of atypical work schedules extend beyond the expression profile of canonical circadian clock genes and affects other transcripts of the human genome. In general, after several days of living at night, most rhythmic transcripts in the human genome remain adjusted to a day-oriented schedule, with dampened group amplitudes. In contrast to circadian clock genes and rhythmic transcripts, metabolomics studies revealed that most metabolites shift by several hours when working nights, thus leading to their misalignment with the circadian system. Altogether, these circadian and sleep-wake disturbances emphasize the all-encompassing impact of night-shift work, and can contribute to the increased risk of various medical conditions. Here, we review the latest scientific evidence regarding the effects of atypical work schedules on the circadian system, sleep and alertness of shift-working populations, and discuss their potential clinical impacts.
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Affiliation(s)
- Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Philippe Boudreau
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Anastasi Kosmadopoulos
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
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Collins BEG, Hartmann TE, Marino FE, Skein M. Inflammatory Status and Cardio-metabolic Risk Stratification of Rotational Shift Work. Ann Work Expo Health 2021; 66:79-88. [PMID: 34219158 DOI: 10.1093/annweh/wxab043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/10/2021] [Accepted: 05/27/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To investigate the physiological effects of rotational shift work on measures of cardio-metabolic function. METHODS Sedentary, healthy men (n = 87; age 37 ± 9 years; body mass index: 30.7 ± 5.1 kg m2) were recruited and categorized via occupation. SHIFT group: currently employed in rotational shift work defined by 8-12 h morning, afternoon, and night rotations; or NSHIFT: working fixed daytime hours. Testing procedures included baseline objective sleep assessment and laboratory testing, conducted between 0600 and 0900 h to assess body composition, cardiorespiratory fitness (VO2peak), inflammatory status [C-reactive protein, interleukin (IL)-6, and tumour necrosis factor-alpha (TNF-α)], glucose metabolism, heart rate variability (HRV), and self-reported leisure time physical activity (PA). RESULTS SHIFT reported significantly less leisure time PA (P = 0.019), reduced VO2peak (P = 0.007), higher body fat percentage (BF%) (P = 0.021), increase response time to oral glucose tolerance test (P = 0.016), and higher IL-6 values (P = 0.008) compared with NSHIFT. A significant difference was observed in actigraphy measured total sleep time, with SHIFT recording reduced sleep following a night shift (P = 0.001). No group difference was observed in HRV or average sleep parameters (P > 0.05). Linear regression identified a significant association between occupation and inflammatory status (P = 0.006). CONCLUSIONS Rotational shift work is associated with increased risk factors for cardio-metabolic disorders, despite no differences in sleep quality and quantity. The results suggest rotational shift work has a detrimental effect on the health and wellbeing of employees; with homeostatic desynchronization identified as potential pathogenic mechanisms.
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Affiliation(s)
- Blake E G Collins
- School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia
| | - Tegan E Hartmann
- School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia
| | - Frank E Marino
- School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia
| | - Melissa Skein
- School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia
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Nieuwenhuys A, Dora J, Knufinke-Meyfroyt M, Beckers D, Rietjens G, Helmhout P. "20,000 leagues under the sea": Sleep, cognitive performance, and self-reported recovery status during a 67-day military submarine mission. APPLIED ERGONOMICS 2021; 91:103295. [PMID: 33130453 DOI: 10.1016/j.apergo.2020.103295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/07/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Employing a field-based monitoring paradigm, the current study examined day-to-day fluctuations in actigraphy-based sleep recordings, cognitive performance (10-min psychomotor vigilance test; PVT), and self-reported recovery status among 14 submariners throughout a 67-day military mission. Mission averages reflected suboptimal sleep that was of short overall duration (5:46 ± 1:29 h per 24-h day) and relatively low efficiency (82.5 ± 9.9%); suboptimal levels of cognitive performance (PVT mRT = 283 ± 35 ms; PVT response errors = 5.3 ± 4.8); and moderate levels of self-reported recovery. Whilst self-reported recovery status remained stable across mission days, small but consistent day-to-day increases in sleep onset latency and PVT mRT accumulated to reflect meaningful deterioration in sleep and cognitive performance across the entire 67-day mission (i.e., 47% and 16% of the overall mission average, respectively). Future work is required to corroborate the current findings, firmly establish underlying causes, and make evidence-based suggestions for interventions to improve and uphold submariners' health and performance.
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Affiliation(s)
- Arne Nieuwenhuys
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand; Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands.
| | - Jonas Dora
- Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands
| | - Melanie Knufinke-Meyfroyt
- Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands; Philips Experience Design, Eindhoven, the Netherlands
| | - Debby Beckers
- Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands
| | - Gerard Rietjens
- Training Medicine and Training Physiology, Army Command, Directory of Personnel, Royal Netherlands Army, Utrecht, the Netherlands; Department of Human Physiology and Sports Medicine, Vrije Universiteit Brussel, Brussels, Belgium
| | - Pieter Helmhout
- Training Medicine and Training Physiology, Army Command, Directory of Personnel, Royal Netherlands Army, Utrecht, the Netherlands
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Anvekar AP, Nathan EA, Doherty DA, Patole SK. Effect of shift work on fatigue and sleep in neonatal registrars. PLoS One 2021; 16:e0245428. [PMID: 33444333 PMCID: PMC7808639 DOI: 10.1371/journal.pone.0245428] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/03/2021] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE We aimed to study fatigue and sleep in registrars working 12-hour rotating shifts in our tertiary neonatal intensive unit. METHODS AND PARTICIPANTS This study involved neonatal registrar's working day (08:00-21:00) and night (20:30-08:30) shifts. Participants maintained a sleep diary, answered a self-reported sleepiness questionnaire assessing subjective sleepiness, and performed a 10-minute psychomotor vigilance task (PVT) at the start and end of each shift. Primary outcomes: (1) Fatigue at the (i) "start vs end" of day and night shifts, (ii) end of the "day vs night" shifts, and (iii) end of "first vs last shift" in block of day and night shifts. (2) Duration and quality of sleep before the "day vs night" shifts. Mean reaction time (RTM), relative coefficient of variation (RTCV), and lapses (reaction time > 500ms) were used as measures of fatigue on PVT. Secondary outcome: Subjective sleepiness (self-reported sleepiness questionnaire) at the 'start vs end" of day and night shifts. RESULTS Fifteen registrars completed the study. Acuity was comparable for all shifts. (1) Psychomotor responses were impaired at the end vs start of day shifts [RTM (p = 0.014), lapses (p = 0.001)], end vs start of night shifts [RTM (p = 0.007), RTCV (p = 0.003), lapses (p<0.001)] and end of night vs day shifts [RTM (p = 0.007), RTCV (p = 0.046), lapses (p = 0.001)]. Only lapses were significantly increased at the end of the last (p = 0.013) vs first shift (p = 0.009) in a block of day and night shifts. (2) Duration of sleep before the night (p = 0.019) and consecutive night shifts was decreased significantly (p = 0.034). Subjective sleepiness worsened after day (p = 0.014) and night shifts (p<0.001). CONCLUSION Fatigue worsened after the 12-hour day and night shifts with a greater change after night shifts. Lapses increased after block of day and night shifts. Sleep was decreased before night shifts. Our findings need to be confirmed in larger studies.
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Affiliation(s)
- Ajay P. Anvekar
- Department of Neonatal Paediatrics, Perth Children Hospital, Perth, Australia
| | - Elizabeth A. Nathan
- Women and Infants Research Foundation, KEM Hospital for Women, Perth, Australia
- Division of Obstetrics and Gynaecology, School of Medicine, University of Western Australia, Perth, Australia
| | - Dorota A. Doherty
- Women and Infants Research Foundation, KEM Hospital for Women, Perth, Australia
- Division of Obstetrics and Gynaecology, School of Medicine, University of Western Australia, Perth, Australia
| | - Sanjay K. Patole
- Department of Neonatal Paediatrics, King Edward Memorial Hospital, Perth, Western Australia, Australia
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia
- * E-mail:
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Stone JE, Aubert XL, Maass H, Phillips AJK, Magee M, Howard ME, Lockley SW, Rajaratnam SMW, Sletten TL. Application of a Limit-Cycle Oscillator Model for Prediction of Circadian Phase in Rotating Night Shift Workers. Sci Rep 2019; 9:11032. [PMID: 31363110 PMCID: PMC6667480 DOI: 10.1038/s41598-019-47290-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 06/17/2019] [Indexed: 12/21/2022] Open
Abstract
Practical alternatives to gold-standard measures of circadian timing in shift workers are needed. We assessed the feasibility of applying a limit-cycle oscillator model of the human circadian pacemaker to estimate circadian phase in 25 nursing and medical staff in a field setting during a transition from day/evening shifts (diurnal schedule) to 3-5 consecutive night shifts (night schedule). Ambulatory measurements of light and activity recorded with wrist actigraphs were used as inputs into the model. Model estimations were compared to urinary 6-sulphatoxymelatonin (aMT6s) acrophase measured on the diurnal schedule and last consecutive night shift. The model predicted aMT6s acrophase with an absolute mean error of 0.69 h on the diurnal schedule (SD = 0.94 h, 80% within ±1 hour), and 0.95 h on the night schedule (SD = 1.24 h, 68% within ±1 hour). The aMT6s phase shift from diurnal to night schedule was predicted to within ±1 hour in 56% of individuals. Our findings indicate the model can be generalized to a shift work setting, although prediction of inter-individual variability in circadian phase shift during night shifts was limited. This study provides the basis for further adaptation and validation of models for predicting circadian phase in rotating shift workers.
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Affiliation(s)
- Julia E Stone
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
| | | | | | - Andrew J K Phillips
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Michelle Magee
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Mark E Howard
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
- Institute for Breathing and Sleep, Austin Health, Victoria, Australia
| | - Steven W Lockley
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Shantha M W Rajaratnam
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Tracey L Sletten
- CRC for Alertness, Safety and Productivity, Melbourne, Victoria, Australia.
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Victoria, Australia.
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Analysis of the Effects of Day-Time vs. Night-Time Surgery on Renal Transplant Patient Outcomes. J Clin Med 2019; 8:jcm8071051. [PMID: 31323849 PMCID: PMC6678185 DOI: 10.3390/jcm8071051] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 02/01/2023] Open
Abstract
Sleep deprivation and disruption of the circadian rhythms could impair individual surgical performance and decision making. For this purpose, this study identified potential confounding factors on surgical renal transplant patient outcomes during day and night. Our retrospective cohort study of 215 adult renal cadaver transplant recipients, of which 132 recipients were allocated in the “day-time” group and 83 recipients in the “night-time” group, primarily stratified the patients into two cohorts, depending on the start time. Within a 24 h operational system, “day-time” was considered as being from 8 a.m. to 8 p.m. and “night-time” from 8 p.m. to 8 a.m.. Primary outcomes examined patient and graft survival after three months and one year. Secondary outcomes included the presence of acute rejection (AR) and delayed graft function (DGF), as well as the rate of postoperative complications. In log-rank testing, “day-time” surgery was associated with a significantly higher risk of patient death (p = 0.003), whereas long-term graft survival was unaffected by the operative time of day. The mean cold ischemia time (CIT), which was 12.4 ± 5.3 h in the “night-time” group, was significantly longer compared to 10.7 ± 3.6 for those during the day (p = 0.01). We observed that “night-time” kidney recipients experienced more wound complications. From our single-centre data, we conclude that night-time kidney transplantation does not increase the risk of adverse events or predispose the patient to a worse outcome. Nevertheless, further research is required to explore the effect of fatigue on nocturnal surgical performance.
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Decreased psychomotor vigilance of female shift workers after working night shifts. PLoS One 2019; 14:e0219087. [PMID: 31276523 PMCID: PMC6611661 DOI: 10.1371/journal.pone.0219087] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/14/2019] [Indexed: 11/22/2022] Open
Abstract
Background We compared psychomotor vigilance in female shift workers of the Bergmannsheil University Hospital in Bochum, Germany (N = 74, 94% nurses) after day and night shifts. Methods Participants performed a 3-minute Psychomotor Vigilance Task (PVT) test bout at the end of two consecutive day and three consecutive night shifts, respectively. Psychomotor vigilance was analyzed with respect to mean reaction time, percentage of lapses and false starts, and throughput as an overall performance score, combining reaction time and error frequencies. We also determined the reaction time coefficient of variation (RTCV) to assess relative reaction time variability after day and night shifts. Further, we examined the influence of shift type (night vs. day) by mixed linear models with associated 95% confidence intervals (CI), adjusted for age, chronotype, study day, season, and the presence of obstructive sleep apnea (OSA). Results At the end of a night shift, reaction times were increased (β = 7.64; 95% CI 0.94; 14.35) and the number of lapses higher compared to day shifts (exp(β) = 1.55; 95% CI 1.16–2.08). By contrast, we did not observe differences in the number of false starts between day and night shifts. Throughput was reduced after night shifts (β = -15.52; 95% CI -27.49; -3.46). Reaction times improved across consecutive day and night shifts, whereas the frequency of lapses decreased after the third night. RTCV remained unaffected by both, night shifts and consecutive shift blocks. Discussion Our results add to the growing body of literature demonstrating that night-shift work is associated with decreased psychomotor vigilance. As the analysis of RTCV suggests, performance deficits may selectively be driven by few slow reactions at the lower end of the reaction time distribution function. Comparing intra-individual PVT-performances over three consecutive night and two consecutive day shifts, we observed performance improvements after the third night shift. Although a training effect cannot be ruled out, this finding may suggest better adaptation to the night schedule if avoiding fast-changing shift schedules.
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15
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Bescos R, Boden MJ, Jackson ML, Trewin AJ, Marin EC, Levinger I, Garnham A, Hiam DS, Falcao-Tebas F, Conte F, Owens J, Kennaway DJ, McConell GK. Four days of simulated shift work reduces insulin sensitivity in humans. Acta Physiol (Oxf) 2018; 223:e13039. [PMID: 29356345 DOI: 10.1111/apha.13039] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 01/15/2018] [Accepted: 01/16/2018] [Indexed: 01/30/2023]
Abstract
AIM The aim of this study was to investigate the effects of 4 consecutive simulated night shifts on glucose homeostasis, mitochondrial function and central and peripheral rhythmicities compared with a simulated day shift schedule. METHODS Seventeen healthy adults (8M:9F) matched for sleep, physical activity and dietary/fat intake participated in this study (night shift work n = 9; day shift work n = 8). Glucose tolerance and insulin sensitivity before and after 4 nights of shift work were measured by an intravenous glucose tolerance test and a hyperinsulinaemic euglycaemic clamp respectively. Muscles biopsies were obtained to determine insulin signalling and mitochondrial function. Central and peripheral rhythmicities were assessed by measuring salivary melatonin and expression of circadian genes from hair samples respectively. RESULTS Fasting plasma glucose increased (4.4 ± 0.1 vs. 4.6 ± 0.1 mmol L-1 ; P = .001) and insulin sensitivity decreased (25 ± 7%, P < .05) following the night shift, with no changes following the day shift. Night shift work had no effect on skeletal muscle protein expression (PGC1α, UCP3, TFAM and mitochondria Complex II-V) or insulin-stimulated pAkt Ser473, pTBC1D4Ser318 and pTBC1D4Thr642. Importantly, the metabolic changes after simulated night shifts occurred despite no changes in the timing of melatonin rhythmicity or hair follicle cell clock gene expression across the wake period (Per3, Per1, Nr1d1 and Nr1d2). CONCLUSION Only 4 days of simulated night shift work in healthy adults is sufficient to reduce insulin sensitivity which would be expected to increase the risk of T2D.
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Affiliation(s)
- R. Bescos
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Institute of Health & Community; Faculty of Health & Human Sciences; University of Plymouth; Plymouth UK
| | - M. J. Boden
- Robinson Research Institute and Adelaide School of Medicine; University of Adelaide; Adelaide SA Australia
- Syneos Health; Hindmarsh SA Australia
| | - M. L. Jackson
- College of Arts; Victoria University; Melbourne Vic. Australia
- School of Health and Biomedical Sciences; RMIT University; Bundoora Vic. Australia
| | - A. J. Trewin
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Department of Anesthesiology; University of Rochester Medical Center; Rochester NY USA
| | - E. C. Marin
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Department of Medicine (Austin Health); Austin Hospital; The University of Melbourne; Melbourne Victoria Australia
| | - I. Levinger
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Australian Institute for Musculoskeletal Science (AIMSS); Western Health; Melbourne Australia
| | - A. Garnham
- School of Exercise and Nutrition Sciences; Deakin University; Melbourne Vic. Australia
| | - D. S. Hiam
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
| | - F. Falcao-Tebas
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
| | - F. Conte
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
| | - J. A. Owens
- Robinson Research Institute and Adelaide School of Medicine; University of Adelaide; Adelaide SA Australia
| | - D. J. Kennaway
- Robinson Research Institute and Adelaide School of Medicine; University of Adelaide; Adelaide SA Australia
| | - G. K. McConell
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
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Saadat S, Karbakhsh M, Saremi M, Alimohammadi I, Ashayeri H, Fayaz M, Sadeghian F, Rostami R. A prospective study of psychomotor performance of driving among two kinds of shift work in Iran. Electron Physician 2018; 10:6417-6425. [PMID: 29629067 PMCID: PMC5878038 DOI: 10.19082/6417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/17/2017] [Indexed: 02/01/2023] Open
Abstract
Background and aim Driving after a night shift imposes a risk on health care professionals and other road users. The aim of this study was to measure psychomotor performance of driving of night shift nurses compared to day-shift nurses. Methods Forty-seven volunteer female nurses working at Sina hospital in Tehran, Iran, with a call in all departments of hospital, participated in this study (23 night shift and 24 day shift nurses) in 2016. The tests included RT for simple reaction time, ATAVT for perceptual speed, LVT for visual orientation and ZBA for time anticipation. Data collection tools were individual characteristics, 11-item circadian type inventory (CTI), Stanford sleepiness scale (SSS), and Swedish occupational fatigue inventory (SOFI-20) questionnaires. Psychomotor driving performance was assessed using validated computerized traffic psychological battery of Vienna Test System (VTS), before and after the shifts. Data analysis was performed using paired-samples t-test and Linear Regression. Results The mean age of day and night-shift nurses were 31.4±5.6 and 28.7±3.9 years respectively, no significant difference between two groups. Thirty percent of night shift and 16.7% of day shift nurses reported traffic accidents in the past year. The results revealed that, scores based on viewing times in visual orientation test (p=0.005), and median reaction time score in choice reaction time and reactive stress tolerance test (p=0.045), had a significant association with a 12-hour night shift with a 3-hour nap. Conclusions Twelve-hour night shift work impairs choice reaction time and visual orientation in nurses, even though they take a 3- hour nap during the shift. These skills are required for safe driving.
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Affiliation(s)
- Soheil Saadat
- MD, PhD, Associate Professor of Epidemiology, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Mojgan Karbakhsh
- MD, PhD of Community Medicine, Associate Professor of Community Medicine, Department of Community Medicine, School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Mahnaz Saremi
- PhD of Ergonomics, Associate Professor, School of Health, Safety and Environment, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Iraj Alimohammadi
- PhD of Occupational Health, Associate Professor of Occupational Health, Department of Occupational Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Ashayeri
- MD, PhD, Professor of Neurology and Psychiatry, Department of Basic Sciences in Rehabilitation, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Mahsa Fayaz
- MSc of Biostatistics, Department of Epidemiology and Biostatistics, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Farideh Sadeghian
- PhD Candidate, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Reza Rostami
- Psychiatrist, Associate Professor, Department of Psychology, Faculty of Psychology and Educational Science, University of Tehran, Tehran, Iran
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Paech GM, Crowley SJ, Fogg LF, Eastman CI. Advancing the sleep/wake schedule impacts the sleep of African-Americans more than European-Americans. PLoS One 2017; 12:e0186887. [PMID: 29059251 PMCID: PMC5653363 DOI: 10.1371/journal.pone.0186887] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 10/09/2017] [Indexed: 12/16/2022] Open
Abstract
There are differences in sleep duration between Blacks/African-Americans and Whites/European-Americans. Recently, we found differences between these ancestry groups in the circadian system, such as circadian period and the magnitude of phase shifts. Here we document the role of ancestry on sleep and cognitive performance before and after a 9-h advance in the sleep/wake schedule similar to flying east or having a large advance in sleep times due to shiftwork, both of which produce extreme circadian misalignment. Non-Hispanic African and European-Americans (N = 20 and 17 respectively, aged 21-43 years) were scheduled to four baseline days each with 8 h time in bed based on their habitual sleep schedule. This sleep/wake schedule was then advanced 9 h earlier for three days. Sleep was monitored using actigraphy. During the last two baseline/aligned days and the first two advanced/misaligned days, beginning 2 h after waking, cognitive performance was measured every 3 h using the Automated Neuropsychological Assessment Metrics (ANAM) test battery. Mixed model ANOVAs assessed the effects of ancestry (African-American or European-American) and condition (baseline/aligned or advanced/misaligned) on sleep and cognitive performance. There was decreased sleep and impaired performance in both ancestry groups during the advanced/misaligned days compared to the baseline/aligned days. In addition, African-Americans obtained less sleep than European-Americans, especially on the first two days of circadian misalignment. Cognitive performance did not differ between African-Americans and European-Americans during baseline days. During the two advanced/misaligned days, however, African-Americans tended to perform slightly worse compared to European-Americans, particularly at times corresponding to the end of the baseline sleep episodes. Advancing the sleep/wake schedule, creating extreme circadian misalignment, had a greater impact on the sleep of African-Americans than European-Americans. Ancestry differences in sleep appear to be exacerbated when the sleep/wake schedule is advanced, which may have implications for individuals undertaking shiftwork and transmeridian travel.
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Affiliation(s)
- Gemma M. Paech
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Stephanie J. Crowley
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Louis F. Fogg
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Charmane I. Eastman
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, United States of America
- * E-mail:
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Kazemi R, Motamedzade M, Golmohammadi R, Mokarami H, Hemmatjo R, Heidarimoghadam R. Field Study of Effects of Night Shifts on Cognitive Performance, Salivary Melatonin, and Sleep. Saf Health Work 2017; 9:203-209. [PMID: 29928535 PMCID: PMC6005914 DOI: 10.1016/j.shaw.2017.07.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 07/02/2017] [Accepted: 07/12/2017] [Indexed: 01/08/2023] Open
Abstract
Background Night shift work is associated with many problems such as sleep deprivation, sleepiness, decreased cognitive performance, increased human errors, and fatigue. This study set out to measure cognitive performance, melatonin rhythms, and sleep after different consecutive night shifts (7 vs. 4) among control room operators (CORs). Methods The participants included 60 CORs with a mean age of 30.2 years (standard deviation, 2.0) from a petrochemical complex located in Southern Iran. Cognitive performance was assessed using the n-back task and continuous performance test. To evaluate melatonin, saliva was collected and tested by enzyme-linked immunosorbent assay. To assess sleep and sleepiness, the Pittsburgh Sleep Quality Index and Karolinska Sleepiness Scale were used, respectively. Results Individuals who worked 7 consecutive night shifts had a significantly better cognitive performance and sleep quality than those who worked 4 consecutive night shifts. However, salivary melatonin profile and sleepiness trend were not affected by shift type. Conclusion The main duty of CORs working night shifts at the studied industry included managing safety-critical processes through complex displays; a responsibility that demands good cognitive performance and alertness. It is suggested that an appropriate number of consecutive night shifts in a rotating shift system should be planned with the ultimate aim of improving CROs performance/alertness and enhancing safety.
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Affiliation(s)
- Reza Kazemi
- Department of Ergonomics, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Majid Motamedzade
- Department of Ergonomics, School of Health, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rostam Golmohammadi
- Department of Ergonomics, School of Health, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamidreza Mokarami
- Department of Ergonomics, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Rasoul Hemmatjo
- Department of Occupational Health, School of Health, Urmia University of Medical Sciences, Urmia, Iran
| | - Rashid Heidarimoghadam
- Department of Ergonomics, School of Health, Hamadan University of Medical Sciences, Hamadan, Iran
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Niu SF, Miao NF, Liao YM, Chi MJ, Chung MH, Chou KR. Sleep Quality Associated With Different Work Schedules: A Longitudinal Study of Nursing Staff. Biol Res Nurs 2017. [DOI: 10.1177/1099800417695483] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose: To explore the differences in sleep parameters between nurses working a slow, forward rotating shift and those working a fixed day shift. Method: A longitudinal parallel-group comparison design was used in this prospective study. Participants (female) were randomly assigned to a rotating shift or a fixed day shift group. Participants in the rotating shift group worked day shift for the first 4 weeks, followed by evening shift for the second and night shift the third. Those in the day shift group worked day shift for all 12 weeks. Each kept a sleep diary and wore an actigraph (actigraph data were used to calculate total sleep time [TST], sleep onset latency [SOL], wake after sleep onset [WASO], and sleep efficiency [SE]) for 12 days, from Workday 1–4 in each of Weeks 4, 8, and 12. Results: TST in nurses working evening rotating shift was higher than that for those working the day or night rotating shift and fixed day shift. WASO was significantly longer on Day 2 for rotating shift participants working evening versus day shift. SOL and SE were significantly shorter and lower in rotating shift nurses working night versus both day and evening shifts. Conclusions: A comprehensive understanding of the sleep patterns and quality of nurses with different work shifts may lead to better management of work shifts that reduces the influence of shift work on sleep quality.
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Affiliation(s)
- Shu-Fen Niu
- School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Nursing Department, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
- Department of Nursing, Fu Jen Catholic University, Taipei, Taiwan
| | - Nae-Fang Miao
- Accelerated Bachelor of Science in Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Yuan-Mei Liao
- School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Institute of Clinical Nursing, School of Nursing, National Yang-Ming University
| | - Mei-Ju Chi
- School of Gerontology Health Management, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Master Program in Long-term Care, College of Nursing, Taipei Medical University
| | - Min-Huey Chung
- School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Kuei-Ru Chou
- School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Department of Nursing, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan
- Psychiatric Research Center, Taipei Medical University Hospital, Taipei, Taiwan
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Sahni JN, Czanner G, Gutu T, Taylor SA, Bennett KM, Wuerger SM, Grierson I, Murray-Dunning C, Holland MN, Harding SP. Safety and acceptability of an organic light-emitting diode sleep mask as a potential therapy for retinal disease. Eye (Lond) 2016; 31:97-106. [PMID: 27983728 DOI: 10.1038/eye.2016.259] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/13/2016] [Indexed: 11/09/2022] Open
Abstract
PurposeThe purpose of the study was to study the effect of an organic light-emitting diode sleep mask on daytime alertness, wellbeing, and retinal structure/function in healthy volunteers and in diabetic macular oedema (DMO).Patients and methodsHealthy volunteers in two groups, 18-30 yrs (A), 50-70 yrs (B) and people with DMO (C) wore masks (504 nm wavelength; 80 cd/m2 luminance; ≤8 h) nightly for 3 months followed by a 1-month recovery period. Changes from baseline were measured for (means): psychomotor vigilance task (PVT) (number of lapses (NL), response time (RT)), sleep, depression, psychological wellbeing (PW), visual acuity, contrast sensitivity, colour, electrophysiology, microperimetry, and retinal thickness on OCT.ResultsOf 60 participants, 16 (27%) withdrew, 8 (13%) before month 1, due to sleep disturbances and mask intolerance. About 36/55 (65%) who continued beyond month 1 reported ≥1 adverse event. At month 3 mean PVT worsened in Group A (RT (7.65%, P<0.001), NL (43.3%, P=0.005)) and mean PW worsened in all groups (A 28.0%, P=0.01, B 21.2%, P=0.03, C 12.8%, P<0.05). No other clinically significant safety signal was detected. Cysts reduced/resolved in the OCT subfield of maximal pathology in 67% Group C eyes. Thinning was greater at 3 and 4 months for greater baseline thickness (central subfield P<0.001, maximal P<0.05).ConclusionSleep masks showed no major safety signal apart from a small impairment of daytime alertness and a moderate effect on wellbeing. Masks were acceptable apart from in some healthy participants. Preliminary data suggest a beneficial effect on retinal thickness in DMO. This novel therapeutic approach is ready for large clinical trials.
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Affiliation(s)
- J N Sahni
- St Paul's Eye Unit, Royal Liverpool University Hospitals NHS Trust, Liverpool, UK.,Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - G Czanner
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK.,Department of Biostatistics, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - T Gutu
- St Paul's Eye Unit, Royal Liverpool University Hospitals NHS Trust, Liverpool, UK
| | - S A Taylor
- St Paul's Eye Unit, Royal Liverpool University Hospitals NHS Trust, Liverpool, UK
| | - K M Bennett
- Department of Psychological Sciences, Institute of Psychology, Health and Society, Liverpool, UK
| | - S M Wuerger
- Department of Psychological Sciences, Institute of Psychology, Health and Society, Liverpool, UK
| | - I Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - C Murray-Dunning
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | | | - S P Harding
- St Paul's Eye Unit, Royal Liverpool University Hospitals NHS Trust, Liverpool, UK.,Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
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21
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Gupta CC, Dorrian J, Grant CL, Pajcin M, Coates AM, Kennaway DJ, Wittert GA, Heilbronn LK, Della Vedova CB, Banks S. It’s not just what you eat but when: The impact of eating a meal during simulated shift work on driving performance. Chronobiol Int 2016; 34:66-77. [DOI: 10.1080/07420528.2016.1237520] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Charlotte C. Gupta
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia, Australia
| | - Jill Dorrian
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia, Australia
| | - Crystal L. Grant
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia, Australia
| | - Maja Pajcin
- School of Pharmacy and Medical Sciences, University of Australia, Australia
| | - Alison M. Coates
- Division of Health Sciences, University of South Australia, Australia
| | - David J. Kennaway
- Robinson Research Institute, Adelaide Medical School, University of Adelaide, Australia
| | - Gary A. Wittert
- Discipline of Medicine, Adelaide Medical School, University of Adelaide, Australia
| | - Leonie K. Heilbronn
- Robinson Research Institute, Discipline of Medicine, Adelaide Medical School, University of Adelaide and South Australia Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | | | - Siobhan Banks
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia, Australia
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22
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Nabe-Nielsen K, Jensen MA, Hansen ÅM, Kristiansen J, Garde AH. What is the preferred number of consecutive night shifts? results from a crossover intervention study among police officers in Denmark. ERGONOMICS 2016; 59:1392-1402. [PMID: 26947135 DOI: 10.1080/00140139.2015.1136698] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 12/19/2015] [Indexed: 06/05/2023]
Abstract
Among police officers in Denmark, we studied (i) how many consecutive night shifts participants preferred at baseline; (ii) preferences regarding three intervention conditions (two, four, and seven consecutive night shifts followed by the same number of days off/day shifts: '2 + 2', '4 + 4', '7 + 7') at follow-up; (iii) characteristics of participants preferring each of these intervention conditions. Questionnaire data from a crossover intervention study were used (baseline: n = 73; follow-up: n = 68). At baseline, 49% preferred four consecutive night shifts. At follow-up, 57% preferred '4 + 4', 26% preferred '2 + 2' and 26% preferred '7 + 7'. Participants, who preferred longer spells of night work experienced that night work was less demanding, found it easier to sleep at different times of the day, and were more frequently evening types compared with participants who preferred shorter spells of night work. The participants' preferences are likely to be influenced by their previous shift work experience. Practitioner Summary: We investigated police officers' preferences regarding the number of consecutive night shifts. The majority preferred four consecutive night shifts. Those who preferred the longer spells of night work found night work less demanding, found it easier to sleep at different times of the day, and were more frequently evening types.
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Affiliation(s)
- Kirsten Nabe-Nielsen
- a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark
| | - Marie Aarrebo Jensen
- a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark
- b The National Research Centre for the Working Environment , Copenhagen , Denmark
| | - Åse Marie Hansen
- a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark
- b The National Research Centre for the Working Environment , Copenhagen , Denmark
| | - Jesper Kristiansen
- b The National Research Centre for the Working Environment , Copenhagen , Denmark
| | - Anne Helene Garde
- a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark
- b The National Research Centre for the Working Environment , Copenhagen , Denmark
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23
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Chinoy ED, Harris MP, Kim MJ, Wang W, Duffy JF. Scheduled evening sleep and enhanced lighting improve adaptation to night shift work in older adults. Occup Environ Med 2016; 73:869-876. [PMID: 27566781 DOI: 10.1136/oemed-2016-103712] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 07/13/2016] [Accepted: 07/20/2016] [Indexed: 01/06/2023]
Abstract
OBJECTIVES We tested whether a sleep and circadian-based treatment shown to improve circadian adaptation to night shifts and attenuate negative effects on alertness, performance and sleep in young adults would also be effective in older adults. METHODS We assessed subjective alertness, sustained attention (psychomotor vigilance task, PVT), sleep duration (actigraphy) and circadian timing (salivary dim-light melatonin onset, DLMO) in 18 older adults (57.2±3.8 years; mean±SD) in a simulated shift work protocol. 4 day shifts were followed by 3 night shifts in the laboratory. Participants slept at home and were randomised to either the treatment group (scheduled evening sleep and enhanced lighting during the latter half of night shifts) or control group (ad-lib sleep and typical lighting during night shifts). RESULTS Compared with day shifts, alertness and sustained attention declined on the first night shift in both groups, and was worse in the latter half of the night shifts. Alertness and attention improved on nights 2 and 3 for the treatment group but remained lower for the control group. Sleep duration in the treatment group remained similar to baseline (6-7 hours) following night shifts, but was shorter (3-5 hours) following night shifts in the control group. Treatment group circadian timing advanced by 169.3±16.1 min (mean±SEM) but did not shift (-9.7±9.9 min) in the control group. CONCLUSIONS The combined treatment of scheduled evening sleep and enhanced lighting increased sleep duration and partially aligned circadian phase with sleep and work timing, resulting in improved night shift alertness and performance.
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Affiliation(s)
- Evan D Chinoy
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Warfighter Performance Department, Naval Health Research Center, San Diego, California, USA‡
| | - Michael P Harris
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Min Ju Kim
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, Davos Hospital, Yongin, Korea‡
| | - Wei Wang
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeanne F Duffy
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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24
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Vincent GE, Aisbett B, Hall SJ, Ferguson SA. Fighting fire and fatigue: sleep quantity and quality during multi-day wildfire suppression. ERGONOMICS 2016; 59:932-940. [PMID: 26452576 DOI: 10.1080/00140139.2015.1105389] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study examined firefighters' sleep quantity and quality throughout multi-day wildfire suppression, and assessed the impact of sleep location, shift length, shift start time and incident severity on these variables. For 4 weeks, 40 volunteer firefighters' sleep was assessed using wrist actigraphy. Analyses revealed that the quantity of sleep obtained on fire days was restricted, and pre- and post-sleep fatigue ratings were higher, compared to non-fire days. On fire days, total sleep time was less when: (i) sleep location was in a tent or vehicle, (ii) shifts were greater than 14 h and (iii) shifts started between 05:00 and 06:00 h. This is the first empirical investigation providing objective evidence that firefighters' sleep is restricted during wildfire suppression. Furthermore, sleep location, shift length and shift start time should be targeted when designing appropriate controls to manage fatigue-related risk and preserve firefighters' health and safety during wildfire events. Practitioner Summary: During multi-day wildfire suppression, firefighters' sleep quantity was restricted, and pre- and post-sleep fatigue ratings were higher, compared to non-fire days. Furthermore, total sleep time was less when: (i) sleep occurred in a tent/vehicle, (ii) shifts were >14 h and (iii) shifts started between 05:00 and 06:00 h.
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Affiliation(s)
- Grace E Vincent
- a Centre for Physical Activity and Nutrition Research , Deakin University , Burwood , Australia
- b Bushfire Co-operative Research Centre , East Melbourne , Australia
| | - Brad Aisbett
- a Centre for Physical Activity and Nutrition Research , Deakin University , Burwood , Australia
- b Bushfire Co-operative Research Centre , East Melbourne , Australia
| | - Sarah J Hall
- a Centre for Physical Activity and Nutrition Research , Deakin University , Burwood , Australia
| | - Sally A Ferguson
- b Bushfire Co-operative Research Centre , East Melbourne , Australia
- c Appleton Institute , Central Queensland University , Wayville , Australia
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25
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Narciso FV, Barela JA, Aguiar SA, Carvalho ANS, Tufik S, de Mello MT. Effects of Shift Work on the Postural and Psychomotor Performance of Night Workers. PLoS One 2016; 11:e0151609. [PMID: 27115868 PMCID: PMC4845980 DOI: 10.1371/journal.pone.0151609] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 03/01/2016] [Indexed: 11/18/2022] Open
Abstract
The purpose of the study was to investigate the effects of shift work on the psychomotor and postural performance of night workers. The study included 20 polysomnography technicians working schedule of 12-h night shift by 36-h off. On the first day of protocol, the body mass and height were measured, and an actigraph was placed on the wrist of each participant. On the second day of protocol, sleepiness by Karolinska Sleepiness Scale, postural control by force platform (30 seconds) and psychomotor performance by Psychomotor Vigilance Task (10 minutes) were measured before and after 12-h night work. Results showed that after 12-h night work, sleepiness increased by 59% (p<0.001), postural control variables increased by 9% (p = 0.048), and 14% (p = 0.006). Mean reaction time, and the number of lapses of attention increased by 13% (p = 0.006) and 425% (p = 0.015), respectively, but the mean reciprocal reaction time decreased by 7%. In addition, there were correlations between sleepiness and postural control variables with opened eyes (r = 0.616, 95% confidence interval [CI] = 0.361-0.815; r = 0.538; 95% CI = 0.280-0.748) and closed eyes (r = 0.557; 95% CI = 0.304-0.764, r = 0497; 95% CI = 0.325-0.715) and a pronounced effect of sleepiness on postural sway (R2 = 0.393; 95% CI = 0.001-0.03). Therefore, 12-h night work system and sleepiness showed a negative impact in postural and psychomotor vigilance performance of night workers. As unexpected, the force platform was feasibility to detect sleepiness in this population, underscoring the possibility of using this method in the workplace to prevent occupational injuries and accidents.
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Affiliation(s)
| | | | | | | | - Sergio Tufik
- Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Marco Túlio de Mello
- Universidade Federal de São Paulo, São Paulo, SP, Brazil
- Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
- * E-mail:
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26
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Leung M, Tranmer J, Hung E, Korsiak J, Day AG, Aronson KJ. Shift Work, Chronotype, and Melatonin Patterns among Female Hospital Employees on Day and Night Shifts. Cancer Epidemiol Biomarkers Prev 2016; 25:830-8. [DOI: 10.1158/1055-9965.epi-15-1178] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/22/2016] [Indexed: 11/16/2022] Open
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27
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Jensen MA, Garde AH, Kristiansen J, Nabe-Nielsen K, Hansen ÅM. The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV): a systematic review of field studies. Int Arch Occup Environ Health 2015; 89:531-45. [PMID: 26464315 DOI: 10.1007/s00420-015-1093-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 09/28/2015] [Indexed: 04/24/2023]
Abstract
PURPOSE The purpose of this review is to summarize the current knowledge from field studies on how many consecutive night shifts are required for adaptation of diurnal rhythms in cortisol, melatonin and heart rate variability (HRV) to night work. METHODS A systematic search of the databases PubMed and Web of Science resulted in 18 studies selected for review. RESULTS Cortisol was measured in five studies, melatonin in 11 studies and HRV in four studies. Diurnal rhythms were assessed by use of several different measures based on three to eight samples per day for cortisol and melatonin and 24-h recordings for HRV. Most of the studies in the review were small studies with less than 30 participants, and most studies evaluated diurnal rhythms after only two consecutive night shifts whereas only six studies used seven or more consecutive night shifts. The majority of studies found that adaptation to night work had not occurred after two consecutive night shifts, whereas a small number found evidence for full adaptation after seven consecutive night shifts based on diurnal rhythms in cortisol and melatonin. CONCLUSION There are methodological differences in the field studies analyzing diurnal rhythms and large diversity in the occupational fields studied. Nevertheless, we conclude that diurnal rhythms in cortisol, melatonin and HRV are not adapted to night work after 1-3 consecutive night shifts. Studies are needed to establish how many consecutive night shifts are needed for full adaptation of diurnal rhythms to night work.
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Affiliation(s)
- Marie Aarrebo Jensen
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014, København K, Denmark.
| | - Anne Helene Garde
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, København Ø, Denmark
| | - Jesper Kristiansen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, København Ø, Denmark
| | - Kirsten Nabe-Nielsen
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014, København K, Denmark
| | - Åse Marie Hansen
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014, København K, Denmark.,National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, København Ø, Denmark
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28
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Petrov ME, Clark CB, Molzof HE, Johnson RL, Cropsey KL, Gamble KL. Sleep Strategies of Night-Shift Nurses on Days Off: Which Ones are Most Adaptive? Front Neurol 2014; 5:277. [PMID: 25566182 PMCID: PMC4271573 DOI: 10.3389/fneur.2014.00277] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/04/2014] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES To determine the off-shift sleep strategies of bi-ethnic night-shift nurses, the relationship between these sleep strategies and adaptation to shift work, and identify the participant-level characteristics associated with a given sleep strategy. METHODS African-American and non-Hispanic White female, night-shift nurses from an academic hospital were recruited to complete a survey on sleep-wake patterns (n = 213). Participants completed the standard shiftwork index and the biological clocks questionnaire to determine sleep strategies and adaptation to night-shift work. In addition, chronotype was determined quantitatively with a modified version of the Munich ChronoType Questionnaire. Most participants worked ~3 consecutive 12-h night-shifts followed by several days off. RESULTS Five sleep strategies used on days off were identified: (a) night stay, (b) nap proxy, (c) switch sleeper, (d) no sleep, and (e) incomplete switcher. Nap proxy and no sleep types were associated with poorer adaptation to night-shift work. The switch sleeper and incomplete switcher types were identified as more adaptive strategies that were associated with less sleep disturbance, a later chronotype, and less cardiovascular problems. CONCLUSION Behavioral sleep strategies are related to adaptation to a typical night-shift schedule among hospital nurses. Nurses are crucial to the safety and well-being of their patients. Therefore, adoption of more adaptive sleep strategies may reduce sleep/wake dysregulation in this population, and improve cardiovascular outcomes.
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Affiliation(s)
- Megan E. Petrov
- College of Nursing and Health Innovation, Arizona State University, Phoenix, AZ, USA
| | - C. Brendan Clark
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hylton E. Molzof
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Russell L. Johnson
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karen L. Cropsey
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karen L. Gamble
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
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29
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Cheng YH, Roach GD, Petrilli RM. Current and future directions in clinical fatigue management: An update for emergency medicine practitioners. Emerg Med Australas 2014; 26:640-4. [PMID: 25394226 DOI: 10.1111/1742-6723.12319] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2014] [Indexed: 12/15/2022]
Abstract
Physicians worldwide are working round the clock to meet the demands of healthcare systems, especially in acute medical settings such as EDs. Demanding shift work schedules cause fatigue and thus deterioration in mood and motor performance. This article explores the effects of sleep deprivation, focusing on cognition, executive decision-making and the implications for clinical care. Humans are capable of functioning and even adapting to sleep restriction; however, clinicians should be aware of pitfalls and absolute minimums for sleep. Fatigue management training shows promise in enhancing safety in aviation and might have a role in medical shift work. Strategic napping improves performance during night shift in the ED, but does not fully negate fatigue. Drugs offer limited benefit for performance under sleep-deprived conditions, and whenever possible, sleep and/or strategic napping takes precedence.
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Affiliation(s)
- Yi Han Cheng
- Appleton Institute, Central Queensland University, Adelaide, South Australia, Australia
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30
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PAECH GM, FERGUSON SA, BANKS S, DORRIAN J, ROACH GD. The influence of break timing on the sleep quantity and quality of fly-in, fly-out shiftworkers. INDUSTRIAL HEALTH 2014; 52:521-30. [PMID: 25224336 PMCID: PMC4273020 DOI: 10.2486/indhealth.2014-0102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/24/2014] [Indexed: 06/03/2023]
Abstract
Although shift and break timing is known to affect the sleep of shiftworkers, this has not been demonstrated in Fly-in, Fly-out (FIFO) settings which, compared to residential based settings, may be favourable for sleep. This study investigated the sleep quantity and quality of shiftworkers working a FIFO operation comprising of shifts, and therefore breaks, across the 24-h day. The sleep of 24 males (50.43 ± 8.57 yr) was measured using actigraphy and sleep diaries. Morning breaks were associated with less sleep (09:00-12:00 h; 4.4 ± 1.3 h) and a poorer sleep quality (06:00-09:00 h; 3.1 ± 1.0, "average") compared to breaks beginning between 00:00 h and 03:00 h (6.8 ± 1.7 h; 2.2 ± 0.9, "good"). Sleep efficiency remained constant regardless of break timing (85.9 ± 5.0% to 89.9 ± 3.5%). Results indicate that even in operations such as FIFO where sleeping conditions are near-optimal and the break duration is held constant, the influence of the endogenous circadian pacemaker on sleep duration is evident.
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Affiliation(s)
- Gemma M. PAECH
- Centre for Sleep Research, University of South Australia,
Australia
| | - Sally A. FERGUSON
- Centre for Sleep Research, University of South Australia,
Australia
- Appleton Institute, Central Queensland University,
Australia
| | - Siobhan BANKS
- Centre for Sleep Research, University of South Australia,
Australia
| | - Jillian DORRIAN
- Centre for Sleep Research, University of South Australia,
Australia
| | - Gregory D. ROACH
- Centre for Sleep Research, University of South Australia,
Australia
- Appleton Institute, Central Queensland University,
Australia
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31
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TAI SY, LIN PC, CHEN YM, HUNG HC, PAN CH, PAN SM, LEE CY, HUANG CT, WU MT. Effects of marital status and shift work on family function among registered nurses. INDUSTRIAL HEALTH 2014; 52:296-303. [PMID: 24909112 PMCID: PMC4243015 DOI: 10.2486/indhealth.2014-0009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/18/2014] [Indexed: 06/03/2023]
Abstract
This study aims to assess the interactive effect of marital status and shift work on family function. A population-based sample of 1,438 nurses between the ages of 20-45 yr was recruited from Taiwan during the period from July 2005 to April 2006 using a mailed questionnaire. The self-administered questionnaire contained information about demographic data, work status, shift work schedule, and the Family APGAR (Adaptation, Partnership, Growth, Affection, and Resolve) Scale, to evaluate family function. Compared to day shift nurses, non-night and rotation shift nurses had 1.53- and 1.38-fold (95% CI=1.09-2.14 and 1.01-1.88) risk to have poor family function after adjusting for other covariates. Married nurses, by contrast, had a 0.44-fold (95% CI=0.29-0.66) risk to have poor family function compared to single nurses. In addition, married nurses who worked non-night or rotation shifts had a significantly higher percent of poor family function than those married nurses working day shifts; however, similar results were not replicated in single nurses. We concluded that shift work and marital status could influence family function.
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Affiliation(s)
- Shu-Yu TAI
- Department of Family Medicine, Kaohsiung Medical University
Hospital, Taiwan
- Department of Family Medicine, Kaohsiung Municipal Ta-Tung
Hospital, Taiwan
| | - Pei-Chen LIN
- Graduate Institute of Department of Public Health, College of
Health Sciences, Kaohsiung Medical University, Taiwan
| | - Yao-Mei CHEN
- School of Nursing, Kaohsiung Medical University, Taiwan
- Department of Nursing, Kaohsiung Municipal Hsiao-Kang
Hospital, Taiwan
| | - Hsin-Chia HUNG
- Graduate Institute of Health Care, Meiho Institute of
Technology, Taiwan
| | - Chih-Hong PAN
- Institute of Occupational Safety and Health, Council of Labor
Affairs, Executive Yuan, Taiwan
| | - Shung-Mei PAN
- Department of Nursing, Kaohsiung Municipal Ta-Tung Hospital,
Taiwan
| | - Chung-Yin LEE
- Department of Family Medicine, Kaohsiung Medical University
Hospital, Taiwan
| | - Chia-Tsuan HUANG
- Department of Family Medicine, Kaohsiung Medical University
Hospital, Taiwan
| | - Ming-Tsang WU
- Department of Family Medicine, Kaohsiung Medical University
Hospital, Taiwan
- Department of Public Health, Kaohsiung Medical University,
Taiwan
- Center of Environmental & Occupational Medicine,
Kaohsiung Municipal Hsiao-Kang Hospital, Taiwan
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32
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Papantoniou K, Pozo OJ, Espinosa A, Marcos J, Castaño-Vinyals G, Basagaña X, Ribas FC, Mirabent J, Martín J, Carenys G, Martín CR, Middleton B, Skene DJ, Kogevinas M. Circadian Variation of Melatonin, Light Exposure, and Diurnal Preference in Day and Night Shift Workers of Both Sexes. Cancer Epidemiol Biomarkers Prev 2014; 23:1176-86. [DOI: 10.1158/1055-9965.epi-13-1271] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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33
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Khajehnasiri F, Akhondzadeh S, Mortazavi SB, Allameh A, Khavanin A, Zamanian Z. Oxidative Stress and Depression among Male Shift Workers in Shahid Tondgouyan Refinery. IRANIAN JOURNAL OF PSYCHIATRY 2014; 9:76-82. [PMID: 25632284 PMCID: PMC4300469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to determine the oxidative stress; serum level of Total Antioxidant Capacity (TAC)and Malondialdehyde (MDA) level and the depression score among the depressed rotational shift workers in Shahid Tondgouyan Refinery in Tehran (Iran). METHODS A cross-sectional study was conducted among all the 189 shift workers in Shahid Tondgouyan oil refinery who were eligible to participate in the study. They did not take any antidepressants for two months or any supplements for two weeks prior to the study entry. Written consent was obtained from the participants. 21- Item Beck Depression Inventory was used to measure the depression level. Furthermore, body weight, height and systolic and diastolic blood pressure were collected from all the participants. The levels of Total Antioxidant Capacity (TAC) and Malondialdehyde (MDA) were measured by 8 ml fasting blood sample. MDA was determined by thiobarbituric acid reaction. Serum total antioxidants were measured using the spectrophotometric ABTS. In the ABTS test, 2,2'-azinobis (3-ethylbenzthiazoline-6-acid) (ABTS) is converted into its radical cation (ABTS•+) by addition of sodium persulphate. This blue-green radical cation absorbs light at 734 nm. ABTS•+ is reactive towards most antioxidants. Descriptive statistics, ANOVA, ANCOVA and regression tests and correlation were used to analyze the data using SPSS software version 16. RESULTS The age of the participants ranged from 21 to 52 years. The mean age of the participants was 30.58 year (±6.97yr). Of all the participants, 28% (n= 53) had no depression symptoms (depression score between 0 and 9), 65.1% (n=123) were categorized as having mild depression (depression score between 10 and 18) and 6.9% (n=13) were categorized as having moderate depression (depression score between 19 and 29). The participants' BMI ranged from 15.9 to 34.3; the mean BMI of the participants was 24.82 kg/m(2) (+ 3.81 kg/m(2)). The mean of the serum TAC level was 2.51 (± 0.56) mg/dl, and the mean serum MDA level was 3.67(± 1.08) μmol/l. There was a significant difference in the mean TAC concentration between the non-depressed group and the group with mild depression (p=0.029). CONCLUSION Depression was associated with reduced mean TAC concentration and an increase in MDA level. There was a linear relationship between the depression score and shift work experience among the rotational shift workers, which showed a high level of stress and depression among the shift-workers.
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Affiliation(s)
- Farahnaz Khajehnasiri
- Department of Social Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahin Akhondzadeh
- Psychiatry and Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences. Tehran, Iran
| | - Seyed Bagher Mortazavi
- Department of Occupational Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abdolamir Allameh
- Department of Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ali Khavanin
- Department of Occupational Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Zahra Zamanian
- Department of occupational Health, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
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Gumenyuk V, Howard R, Roth T, Korzyukov O, Drake CL. Sleep loss, circadian mismatch, and abnormalities in reorienting of attention in night workers with shift work disorder. Sleep 2014; 37:545-56. [PMID: 24587577 DOI: 10.5665/sleep.3494] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Permanent night-shift workers may develop shift-work disorder (SWD). In the current study, we evaluated neurophysiological and behavioral indices of distractibility across times prior to the night shift (T1), during night hours (T2), and after acute sleep deprivation (T3) in permanent hospital night workers with and without SWD. METHODS Ten asymptomatic night workers (NW) and 18 NW with SWD participated in a 25-h sleep deprivation study. Circadian phase was evaluated by dim-light salivary melatonin onset (DLMO). Objective sleepiness was evaluated using the Multiple Sleep Latency Test (MSLT). Electrophysiological distractibility was evaluated by brain event-related potentials (ERP), whereas behavioral distractibility was evaluated by performance on a visual task in an auditory-visual distraction paradigm. STATISTICAL ANALYSES Comparisons of ERP results were performed by repeated-measures analysis of variance, and t-tests were used where appropriate. A Mann-Whitney U test was used for comparison of variables (MLST, Stanford Sleepiness Scale, and DLMO) that deviated from normal. RESULTS First, in the SWD group, the reorienting negativity ERP amplitude was significantly attenuated compared to that in the NW group. Second, the SWD group had shorter MSLT during night shift hours (4.8 ± 4.9 min) compared to that in NW (7.8 ± 3.7 min; U = 47; z = -2.1; P < 0.03). Third, NW with SWD had a DLMO at 20:27 ± 5.0 h, whereas healthy NW had a DLMO at 05:00 ± 3.4 h (U = 43.5; z = -2.22, P < 0.03). Finally, acute sleep deprivation impaired behavioral performance and the P3a ERP in both groups. CONCLUSIONS Our results demonstrate specific deficits in neurophysiological activity in the attentional domain among the shift-work disorder group relative to night workers.
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Affiliation(s)
- Valentina Gumenyuk
- Henry Ford Health System, Sleep Disorders and Research Center, Detroit, MI
| | - Ryan Howard
- Henry Ford Health System, Sleep Disorders and Research Center, Detroit, MI
| | - Thomas Roth
- Henry Ford Health System, Sleep Disorders and Research Center, Detroit, MI
| | - Oleg Korzyukov
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL
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Boughattas W, Maalel OE, Chikh RB, Maoua M, Houda K, Braham A, Rhif H, Chatti S, Debbabi F, Dogui M, Mrizak N. Hospital Night Shift and Its Effects on the Quality of Sleep, the Quality of Life, and Vigilance Troubles among Nurses. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ijcm.2014.510079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Chau YM, West S, Mapedzahama V. Night Work and the Reproductive Health of Women: An Integrated Literature Review. J Midwifery Womens Health 2013; 59:113-26. [DOI: 10.1111/jmwh.12052] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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Boudreau P, Dumont GA, Boivin DB. Circadian adaptation to night shift work influences sleep, performance, mood and the autonomic modulation of the heart. PLoS One 2013; 8:e70813. [PMID: 23923024 PMCID: PMC3724779 DOI: 10.1371/journal.pone.0070813] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 06/23/2013] [Indexed: 12/19/2022] Open
Abstract
Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV). Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laboratory for 48 h before and after a series of 7 consecutive night shifts in the field. The nighttime and daytime sleep periods were scheduled during the first and second laboratory visit, respectively. The subjects were considered "adapted" to night shifts if their peak salivary melatonin occurred during their daytime sleep period during the second visit. The sleep duration and quality were comparable between laboratory visits in the adapted group, whereas they were reduced during visit 2 in the non-adapted group. Reaction speed was higher at the end of the waking period during the second laboratory visit in the adapted compared to the non-adapted group. Sleep onset latency (SOL) and subjective mood levels were significantly reduced and the LF∶HF ratio during daytime sleep was significantly increased in the non-adapted group compared to the adapted group. Circadian adaptation to night shift work led to better performance, alertness and mood levels, longer daytime sleep, and lower sympathetic dominance during daytime sleep. These results suggest that the degree of circadian adaptation to night shift work is associated to different health indices. Longitudinal studies are required to investigate long-term clinical implications of circadian misalignment to atypical work schedules.
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Affiliation(s)
- Philippe Boudreau
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Guy A. Dumont
- Department of Electrical and Computer Engineering, University of British Colombia, Vancouver, British Colombia, Canada
| | - Diane B. Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
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38
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Rahman SA, Shapiro CM, Wang F, Ainlay H, Kazmi S, Brown TJ, Casper RF. Effects of filtering visual short wavelengths during nocturnal shiftwork on sleep and performance. Chronobiol Int 2013; 30:951-62. [PMID: 23834705 PMCID: PMC3786545 DOI: 10.3109/07420528.2013.789894] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Circadian phase resetting is sensitive to visual short wavelengths (450-480 nm). Selectively filtering this range of wavelengths may reduce circadian misalignment and sleep impairment during irregular light-dark schedules associated with shiftwork. We examined the effects of filtering short wavelengths (<480 nm) during night shifts on sleep and performance in nine nurses (five females and four males; mean age ± SD: 31.3 ± 4.6 yrs). Participants were randomized to receive filtered light (intervention) or standard indoor light (baseline) on night shifts. Nighttime sleep after two night shifts and daytime sleep in between two night shifts was assessed by polysomnography (PSG). In addition, salivary melatonin levels and alertness were assessed every 2 h on the first night shift of each study period and on the middle night of a run of three night shifts in each study period. Sleep and performance under baseline and intervention conditions were compared with daytime performance on the seventh day shift, and nighttime sleep following the seventh daytime shift (comparator). On the baseline night PSG, total sleep time (TST) (p < 0.01) and sleep efficiency (p = 0.01) were significantly decreased and intervening wake times (wake after sleep onset [WASO]) (p = 0.04) were significantly increased in relation to the comparator night sleep. In contrast, under intervention, TST was increased by a mean of 40 min compared with baseline, WASO was reduced and sleep efficiency was increased to levels similar to the comparator night. Daytime sleep was significantly impaired under both baseline and intervention conditions. Salivary melatonin levels were significantly higher on the first (p < 0.05) and middle (p < 0.01) night shifts under intervention compared with baseline. Subjective sleepiness increased throughout the night under both conditions (p < 0.01). However, reaction time and throughput on vigilance tests were similar to daytime performance under intervention but impaired under baseline on the first night shift. By the middle night shift, the difference in performance was no longer significant between day shift and either of the two night shift conditions, suggesting some adaptation to the night shift had occurred under baseline conditions. These results suggest that both daytime and nighttime sleep are adversely affected in rotating-shift workers and that filtering short wavelengths may be an approach to reduce sleep disruption and improve performance in rotating-shift workers.
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Affiliation(s)
- Shadab A Rahman
- Fran and Lawrence Bloomberg Department of Obstetrics and Gynecology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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Barber LK, Barnes CM, Carlson KD. Random and Systematic Error Effects of Insomnia on Survey Behavior. ORGANIZATIONAL RESEARCH METHODS 2013. [DOI: 10.1177/1094428113493120] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Insomnia is a prevalent experience among employees and survey respondents. Drawing from research on sleep and self-regulation, we examine both random (survey errors) and systematic (social desirability) effects of research participant insomnia on survey responses. With respect to random effects, we find that insomnia leads to increased survey errors, and that this effect is mediated by a lack of self-control and a lack of effort. However, insomnia also has a positive systematic effect, leading to lower levels of social desirability. This effect is also mediated by self-control depletion and a lack of effort. In supplemental analyses, we find that psychometric side effects of random and systematic error introduced by individuals high in insomnia negatively affect internal consistency estimates and measurement invariance on various organizational measures. Results were replicated across two studies, with alternative operationalizations of survey errors and social desirability and some alternative explanations examined. These findings suggest sleep may be a key methodological issue for conducting survey research. Recommendations from the sleep and self-regulation literature regarding potential strategies for counteracting the effect of insomnia on survey responses are discussed.
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Affiliation(s)
- Larissa K. Barber
- Department of Psychology, Northern Illinois University, DeKalb, IL, USA
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Total antioxidant capacity and malondialdehyde in depressive rotational shift workers. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2013; 2013:150693. [PMID: 23690799 PMCID: PMC3649589 DOI: 10.1155/2013/150693] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Revised: 02/20/2013] [Accepted: 03/07/2013] [Indexed: 11/18/2022]
Abstract
Shift work is associated with sleep deprivation, occupational stress, and increased risk of depression. Depressed patients show increased oxidative stress. During excessive oxidative stress, Malondialdehyde (MDA) increases and total antioxidant capacity (TAC) decreases in body. This cross-sectional study was conducted to determine the serum level of TAC and MDA among depressed rotational shift workers in Shahid Tondooyan Tehran Oil Refinery. 21-item Beck Depression Inventory was used to measure depression level. The level of TAC and MDA was measured by 8 mL fasting blood sample. MDA was determined by thiobarbituric acid reaction. Serum total antioxidants were measured using the ABTS. Results of this study showed that TAC mean and standard deviation concentration was 2.451 (±0.536) mg/dL and MDA was 3.725 (±1.098) mic·mol/L, and mean and standard deviation of depression score and BMI were 14.07 (±3.84) and 24.92 (±3.65) kg/m2, respectively. Depression score had a positive correlation with rotational shift work experience and work experience (r = 0.218 and r = 0.212), respectively, (P < 0.05).
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Boivin DB, Boudreau P, James FO, Kin NMKNY. Photic resetting in night-shift work: impact on nurses' sleep. Chronobiol Int 2012; 29:619-28. [PMID: 22621359 DOI: 10.3109/07420528.2012.675257] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleep/darkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1 ± .1 h (mean ± SEM) versus 6.6 ± .2 h for workers in the control group (p = .04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca ).
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Affiliation(s)
- Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, Québec, Canada.
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Nahm ES, Warren J, Zhu S, An M, Brown J. Nurses' self-care behaviors related to weight and stress. Nurs Outlook 2012; 60:e23-31. [DOI: 10.1016/j.outlook.2012.04.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 04/01/2012] [Accepted: 04/22/2012] [Indexed: 10/28/2022]
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Vetter C, Juda M, Roenneberg T. The Influence of Internal Time, Time Awake, and Sleep Duration on Cognitive Performance in Shiftworkers. Chronobiol Int 2012; 29:1127-38. [DOI: 10.3109/07420528.2012.707999] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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44
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Boivin DB, Boudreau P, Tremblay GM. Phototherapy and Orange-Tinted Goggles for Night-Shift Adaptation of Police Officers on Patrol. Chronobiol Int 2012; 29:629-40. [DOI: 10.3109/07420528.2012.675252] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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45
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Niu SF, Chu H, Chen CH, Chung MH, Chang YS, Liao YM, Chou KR. A Comparison of the Effects of Fixed- and Rotating-Shift Schedules on Nursing Staff Attention Levels. Biol Res Nurs 2012; 15:443-50. [DOI: 10.1177/1099800412445907] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Purpose: Sleep deficit affects neurobehavioral functioning, reduces attention and cognitive function, and negatively impacts occupational safety. This study investigated selective attention levels of nursing staff on different shifts. Methods: Using a prospective, randomized parallel group study, selective attention was measured using the d2 test in 62 nursing staff in a medical center in Taiwan. Findings: There were significant differences in selective attention indicators (E%) between the fixed-day-shift group (control group) and rotating-shift group (experimental group): The percentage of errors (E%) for night-shift workers in the rotating-shift group was higher than that of fixed-day-shift workers, while the total number of items scanned minus error (TN − E) and concentration performance (CP) scores were higher for fixed-day-shift workers. Within the experimental group, the error rate on night shift was 0.44 times more than that on day shift and .62 times more than on evening shift; the TN-E on night shift was 38.99 items less than that on day shift, and the CP was 27.68 items less on night shift than on day shift; indicating that staff on the night shift demonstrated poorer speed and accuracy on the overall test than did the staff on day shifts. Conclusions: Inadequate sleep and a state of somnolence adversely affected the attention and operation speed of work among night-shift workers. More than 2 days off is suggested when shifting from the night shift to other shifts to provide adequate time for circadian rhythms to adjust.
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Affiliation(s)
- Shu-Fen Niu
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Department of Nursing, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Hsin Chu
- Institute of Aerospace Medicine, School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Department of Neurology, Tri-Service General Hospital, Taipei , Taiwan
| | | | - Min-Huey Chung
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Yu-Shiun Chang
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Yuan-Mei Liao
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Kuei-Ru Chou
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
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Abstract
The study investigated the number of days off nurses working night shifts need to recover their sleep quality to the level of daytime workers during their days off. This study included 30 day-shift nurses and 32 night-shift nurses. It was conducted as a randomized clinical trial in the medical and surgical wards of a medical center in northern Taiwan in May and June 2010 using sleep diaries and sleep parameters collected by actigraphy on different workdays and days off. On workdays, the night-shift group had significantly less total sleep time (TST) on Day 5 and significantly lower sleep efficiency (SE) on Day 3 than the day-shift group. TSTs of the two groups on days off were higher than those on workdays. On the 4th consecutive day off, higher TST, a decrease in WASO, and an increase in SE suggests that the night-shift group had recovered their sleep quality to the level of the day-shift group on their days off. The SE of the night-shift group exceeded that of the day-shift group after the 4th consecutive day off, though the difference was not statistically significant in the present study. Based on these data, it is recommended that night-shift workers arrange a period of at least 4 days off after 5 consecutive night shifts and at least 5 days off if the staff who have previously worked night shifts are being assigned a set of different shifts.
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Affiliation(s)
- Shu-Fen Niu
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
- Department of Nursing, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Hsin Chu
- Institute of Aerospace and Undersea Medicine, School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Department of Neurology, Tri-Service General Hospital, Taipei, Taiwan
| | - Min-Huey Chung
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Chun-Chieh Lin
- Department of Neurology, Tri-Service General Hospital, Taipei, Taiwan
| | - Yu-Shiun Chang
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Kuei-Ru Chou
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan
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CHAPDELAINE SIMON, PAQUET JEAN, DUMONT MARIE. Effects of partial circadian adjustments on sleep and vigilance quality during simulated night work. J Sleep Res 2012; 21:380-9. [DOI: 10.1111/j.1365-2869.2012.00998.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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48
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Atypical work schedules are associated with poor sleep quality and mental health in Taiwan female nurses. Int Arch Occup Environ Health 2011; 85:877-84. [DOI: 10.1007/s00420-011-0730-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 12/07/2011] [Indexed: 11/29/2022]
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The effect of shift rotation on employee cortisol profile, sleep quality, fatigue, and attention level: a systematic review. J Nurs Res 2011; 19:68-81. [PMID: 21350389 DOI: 10.1097/jnr.0b013e31820c1879] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Disrupted circadian rhythm, especially working night duty together with irregular sleep patterns, sleep deprivation, and fatigue, creates an occupational health risk associated with diminished vigilance and work performance. PURPOSE This study reviewed the effect of shift rotations on employee cortisol profile, sleep quality, fatigue, and attention level. METHODS Researchers conducted a systematic review of relevant articles published between 1996 and 2008 that were listed on the following databases: SCOPUS, OVID, Blackwell Science, EBSCO Host, PsycINFO, Cochrane Controlled Trials Register, and CEPS. A total of 28 articles were included in the review. RESULTS Previous research into the effects of shift work on cortisol profiles, sleep quality, fatigue, and attention used data assessed at evidence Levels II to IV. Our systematic review confirmed a conflict between sleep-wake cycle and light-dark cycle in night work. Consequences of circadian rhythm disturbance include disruption of sleep, decreased vigilance, general feeling of malaise, and decreased mental efficiency. Shift workers who sleep during the day (day sleepers) experience cortisol secretion increases, which diminish the healing power of sleep and enjoy 1 to 4 hours less sleep on average than night sleepers. Sleep debt accumulation results in chronic fatigue. Prolonged fatigue and inadequate recovery result in decreased work performance and more incidents. Rotation from day shift to night shift and its effect on shift workers was a special focus of the articles retained for review. CONCLUSIONS Disturbed circadian rhythm in humans has been associated with a variety of mental and physical disorders and may negatively impact on work safety, performance, and productivity.
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50
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Anjum B, Verma NS, Tiwari S, Singh R, Mahdi AA, Singh RB, Singh RK. Association of salivary cortisol with chronomics of 24 hours ambulatory blood pressure/heart rate among night shift workers. Biosci Trends 2011; 5:182-8. [DOI: 10.5582/bst.2011.v5.4.182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Baby Anjum
- Departments of Biochemistry, C S M Medical University
| | | | | | - Ranjana Singh
- Departments of Biochemistry, C S M Medical University
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