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Burek K, Rabstein S, Kantermann T, Vetter C, Wang-Sattler R, Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Altered coordination between sleep timing and cortisol profiles in night working female hospital employees. Psychoneuroendocrinology 2024; 166:107066. [PMID: 38723404 DOI: 10.1016/j.psyneuen.2024.107066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 06/16/2024]
Abstract
BACKGROUND Cortisol typically peaks in the morning after waking up and declines throughout the day, reaching its lowest levels during nighttime sleep. Shift work can cause misalignment between cortisol levels and sleep-wake timing. We analyzed this misalignment in female shift workers focusing on the timing and extent of these changes. METHODS We conducted a cross-sectional study involving 68 shift workers (aged 37 ± 10 years) and 21 non-shift workers (aged 45 ± 10 years) from a hospital. Shift workers were monitored through two day shifts and three night shifts, whereas non-shift workers were monitored during two day shifts. Each participant collected six to eight saliva samples (depending on their shift type) and provided sleep timing information, which was recorded via polysomnography and sleep diaries. Generalized additive mixed models were used to estimate shift-specific differences in cortisol smooth curves. Summary measures calculated for the cortisol smooth curves included cortisol awakening response, peak-to-bed slope, and total output. RESULTS Between shift workers and non-shift workers, we observed similar diurnal cortisol profiles with a steep negative diurnal slope during day shifts. In shift workers on night shifts, a flattened U-shaped cortisol profile after the post-awakening maximum was observed, with a peak-to-bed slope close to zero. When comparing night to day shifts in the group of shift workers, mean cortisol levels were lower between 42 and 56 minutes and 1.8-11.9 hours after waking up, and higher between 14.9 and 22 hours after waking up. CONCLUSION Our findings indicate altered cortisol profiles in female hospital employees on night shifts. Specifically, cortisol levels were lower at night when higher levels would typically be necessary for work activities, and higher at bedtime after a night shift, when levels should normally be low.
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Affiliation(s)
- Katarzyna Burek
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany.
| | - Sylvia Rabstein
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany
| | - Thomas Kantermann
- Institute for Labor and Personnel (IAP), University of Applied Sciences for Economics and Management (FOM), Essen, Germany; SynOpus, Bochum, Germany
| | - Céline Vetter
- Department of Integrative Physiology, University of Colorado, Boulder, CO, United States
| | - Rui Wang-Sattler
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research (DZD), München, Neuherberg, Germany
| | - Martin Lehnert
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany
| | - Dirk Pallapies
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany
| | - Karl-Heinz Jöckel
- Institute for Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
| | - Thomas Brüning
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany
| | - Thomas Behrens
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Institute of the Ruhr-Universität Bochum, Bochum, Germany
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Nabe-Nielsen K, Larsen AD, Arup AESF, Sallerup M, Schlünssen V, Hansen ÅM, Garde AH. Sleep duration and quality in permanent night work: an observational field study. Int Arch Occup Environ Health 2024:10.1007/s00420-024-02080-0. [PMID: 38907030 DOI: 10.1007/s00420-024-02080-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 06/05/2024] [Indexed: 06/23/2024]
Abstract
PURPOSE Permanent night workers conceivably show better adaptation of circadian rhythms to night work than shift workers and therefore better possibilities of obtaining sufficient sleep of good quality after night shifts. We investigated the effect of night shifts including number of consecutive shifts on sleep among self-selected permanent night workers, and studied if the effect of night shifts differed between morning and evening types and compared with 3-shift workers. METHODS The study population included 90 permanent night workers followed for 14 days (warehouse workers, 1228 observation days, 80% males). For comparison, we included 70 3-shift workers followed for 26 days (police officers, 1774 observation days, 100% men). Total sleep time (TST), primary sleep duration (PSD), and sleep efficiency were assessed by actigraphy. Measures of sleep quality and diurnal type were self-reported. RESULTS Among permanent night workers, TST, PSD, difficulties falling asleep, disturbed sleep, and the number of awakenings decreased after night shifts compared with days without night work. Sleep efficiency, difficulties awakening, and non-refreshing sleep increased. More consecutive night shifts were associated with shorter TST and PSD. Sleep outcomes did not differ by diurnal type. Permanent night workers had fewer awakenings after night shifts than 3-shift workers, but no other differences were observed. CONCLUSION This study does not provide evidence that supports recommendation of permanent night work to reduce adverse effects of night shifts on sleep. A limited number of consecutive night shifts is recommended to reduce accumulation of sleep debt.
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Affiliation(s)
- Kirsten Nabe-Nielsen
- The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark.
- Department of Public Health, Section of Social Medicine, University of Copenhagen, Centre for Health and Society, Øster Farimagsgade 5, 1014, Copenhagen, Denmark.
| | - Ann Dyreborg Larsen
- The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
| | | | - Mette Sallerup
- The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
| | - Vivi Schlünssen
- Department of Public Health, Danish Ramazzini Centre, Research Unit for Environment, Occupation and Health, Bartholins Allé 2, 8000, Aarhus C, Denmark
| | - Åse Marie Hansen
- The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
- Department of Public Health, Section of Social Medicine, University of Copenhagen, Centre for Health and Society, Øster Farimagsgade 5, 1014, Copenhagen, Denmark
| | - Anne Helene Garde
- The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen, Denmark
- Department of Public Health, Section of Social Medicine, University of Copenhagen, Centre for Health and Society, Øster Farimagsgade 5, 1014, Copenhagen, Denmark
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Tseng YJ, Leicht AS, Pagaduan JC, Chien LC, Wang YL, Kao CS, Lu WS, Chen YS. Effects of shift work on sleep quality and cardiovascular function in Taiwanese police officers. Chronobiol Int 2024; 41:530-538. [PMID: 38421010 DOI: 10.1080/07420528.2024.2324023] [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: 04/11/2023] [Accepted: 02/18/2024] [Indexed: 03/02/2024]
Abstract
This study aimed to investigate the effects of shift work on sleep quality, cardiovascular function, and physical activity (PA) levels in Taiwanese police officers. Twenty-one male police officers aged 26.9 ± 4.1 years old located in Taipei voluntarily participated in this study. The participants completed the resting heart rate (HR) and hemodynamic variables (e.g. blood pressure, BP) before and after day-time (DTW) and night-time (NTW) shift work phases (5 working days and 2 resting days for each phase). Additionally, an actigraphy was administered to measure PA and sleep patterns in the last 3 working days. The average total sleep time and sleep efficiency were 278.5 ± 79. 6 min and 72.9 ± 10%, respectively, in the NTW phases, which were significantly lower than that in the DTW phases. A comparison of the PA characteristics between the two phases revealed that a lower proportion of moderate-vigorous PA (1.2 ± 0.8%) and a greater proportion of sedentary behaviour PA (74.8 ± 6.4%) was found in the NTW phases. The results of hemodynamic measures demonstrated that the police officers have significantly elevated systolic BP by 3.3% and diastolic BP by 3.9% after the NTW phases. Furthermore, the NTW phases exhibited a significantly higher percentage change ratio of systolic BP and diastolic BP compared to the DTW phases. Compared with the DTW phases, the NTW phase was significantly more likely to report higher decreasing parasympathetic-related HR variability with a range of -5.9% to -7.8%. In conclusion, night-time shift work resulted in negative physiological changes leading to adverse effects on the health and well-being of Taiwanese police officers.
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Affiliation(s)
- Yen-Ju Tseng
- Department of Exercise and Health Sciences, University of Taipei, Taipei, Taiwan
- Special Police First Headquarters, National Police Agency, Taipei, Taiwan
| | - Anthony S Leicht
- Sport and Exercise Science, James Cook University, Townsville, Australia
- Australian Institute of Tropical Health & Medicine, James Cook University, Townsville, Australia
| | - Jeffrey Cayaban Pagaduan
- Faculty of Physical Culture, Institute of Active Lifestyle, Palacký University, Olomouc, Czechia
| | - Ling-Chu Chien
- School of Public Health, Taipei Medical University, Taipei, Taiwan
- Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan
- Nutrition Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Ying-Lin Wang
- School of Public Health, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan
| | - Chi-Sian Kao
- School of Public Health, Taipei Medical University, Taipei, Taiwan
| | - Wei-Szu Lu
- Department of Administrative Management, Central Police University, Taoyuan, Taiwan
| | - Yung-Sheng Chen
- Department of Exercise and Health Sciences, University of Taipei, Taipei, Taiwan
- Exercise and Health Promotion Association, New Taipei City, Taiwan
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Matre D, Sallinen M, Phillips AJK, Moen LV, Nilsen KB, Haugen F. Night work, season and alertness as occupational safety hazards in the Arctic: protocol for the Noralert observational crossover study among Norwegian process operators. BMJ Open 2023; 13:e075107. [PMID: 37793926 PMCID: PMC10551971 DOI: 10.1136/bmjopen-2023-075107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/11/2023] [Indexed: 10/06/2023] Open
Abstract
INTRODUCTION The objective of this study is to determine the effects of night work, Arctic seasonal factors and cold working environments on human functions relevant to safety. The study aims to quantify the contribution of (1) several consecutive night shifts, (2) seasonal variation on sleepiness, alertness and circadian rhythm and (3) whether a computational model of sleep, circadian rhythms and cognitive performance can accurately predict the observed sleepiness and alertness. METHODS AND ANALYSIS In an observational crossover study of outdoor and indoor workers (n=120) on a three-shift schedule from an industrial plant in Norway (70 °N), measurements will be conducted during the summer and winter. Sleep duration and quality will be measured daily by smartphone questionnaire, aided by actigraphy and heart rate measurements. Sleepiness and alertness will be assessed at regular intervals by the Karolinska Sleepiness Scale and the psychomotor vigilance test, respectively. Saliva samples will assess melatonin levels, and a blood sample will measure circadian time. Thermal exposures and responses will be measured by sensors and by thermography. ETHICS AND DISSEMINATION All participants will give written informed consent to participate in the study, which will be conducted in accordance with the Declaration of Helsinki. The Norwegian Regional Committee for Medical Research Ethics South-East D waivered the need for ethics approval (reference 495816). Dissemination plans include academic and lay publications, and partnerships with national and regional policymakers.
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Affiliation(s)
- Dagfinn Matre
- National Institute of Occupational Health, Oslo, Norway
| | - Mikael Sallinen
- Finnish Institute of Occupational Health, Työterveyslaitos, Finland
| | | | | | | | - Fred Haugen
- National Institute of Occupational Health, Oslo, Norway
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Bracci M, Zingaretti L, Martelli M, Lazzarini R, Salvio G, Amati M, Milinkovic M, Ulissi A, Medori AR, Vitale E, Ledda C, Santarelli L. Alterations in Pregnenolone and Testosterone Levels in Male Shift Workers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3195. [PMID: 36833889 PMCID: PMC9964973 DOI: 10.3390/ijerph20043195] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 06/01/2023]
Abstract
Steroid hormone levels are closely related to the endogenous circadian rhythm induced by sleep-wake and dark-light cycles. Shift work that disrupts the circadian rhythm may influence the levels of steroid hormones. The association between shift work and alterations in female sex steroid hormone levels has been studied, but little is known about testosterone and its precursor pregnenolone levels in male shift workers. The present study investigated serum pregnenolone and testosterone levels in a group of shift and daytime male workers. All participants were sampled at the beginning of the morning shift. Lower levels of serum pregnenolone and total testosterone were found in the shift workers compared to the daytime workers. Variations in pregnenolone levels may have consequences for well-being, and they might produce consequences for the levels of hormones downstream of the steroid hormone cascade, such as testosterone. The low levels of testosterone found in shift workers demonstrate the perturbative effect of shift work on testosterone serum levels, which may be independent and/or related to pregnenolone synthesis.
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Affiliation(s)
- Massimo Bracci
- Occupational Health, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Laura Zingaretti
- Occupational Medicine Unit, Management Staff Department, Marche University Hospital, 60126 Ancona, Italy
| | - Margherita Martelli
- Occupational Health, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Raffaella Lazzarini
- Occupational Health, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Gianmaria Salvio
- Endocrinology Clinic, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Monica Amati
- Occupational Health, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Marijana Milinkovic
- Occupational Medicine Unit, Department of Medical and Surgical Specialties, Marche University Hospital, 60126 Ancona, Italy
| | - Alfio Ulissi
- Occupational Medicine Unit, Management Staff Department, Marche University Hospital, 60126 Ancona, Italy
| | - Anna Rita Medori
- Occupational Medicine Unit, Management Staff Department, Marche University Hospital, 60126 Ancona, Italy
| | - Ermanno Vitale
- Section of Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, 95124 Catania, Italy
| | - Caterina Ledda
- Section of Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, 95124 Catania, Italy
| | - Lory Santarelli
- Occupational Health, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, 60126 Ancona, Italy
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Teoh AN, Kaur S, Shafie SR, Mohd Shukri NH, Ahmad Bustami N, Takahashi M, Shibata S. Chrononutrition is associated with melatonin and cortisol rhythm during pregnancy: Findings from MY-CARE cohort study. Front Nutr 2023; 9:1078086. [PMID: 36687684 PMCID: PMC9852999 DOI: 10.3389/fnut.2022.1078086] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Chrononutrition has been suggested to have an entrainment effect on circadian rhythm which is crucial for metabolic health. Investigating how chrononutrition affects maternal circadian rhythm can shed light on its role during pregnancy. This study aims to determine chrononutrition characteristics of healthy primigravida during pregnancy and its association with melatonin and cortisol rhythm across gestation. A total of 70 healthy primigravidas were recruited from ten randomly selected government maternal and child clinics in Kuala Lumpur, Malaysia. During the second and third trimesters, chrononutrition characteristics including meal timing, frequency, eating window, breakfast skipping, and late-night eating were determined using a 3-day food record. Pregnant women provided salivary samples at five time-points over a 24 h period for melatonin and cortisol assay. Consistently across the second and third trimesters, both melatonin and cortisol showed a rhythmic change over the day. Melatonin levels displayed an increment toward the night whilst cortisol levels declined over the day. Majority observed a shorter eating window (≤12 h) during the second and third trimesters (66 and 55%, respectively). Results showed 23 and 28% skipped breakfast whereas 45 and 37% ate within 2 h pre-bedtime. During the third trimester, a longer eating window was associated with lower melatonin mean (β = -0.40, p = 0.006), peak (β = -0.42, p = 0.006), and AUCG (β = -0.44, p = 0.003). During both trimesters, a lower awakening cortisol level was observed in pregnant women who skipped breakfast (β = -0.33, p = 0.029; β = -0.29, p = 0.044). Only during the second trimester, breakfast-skipping was significantly associated with a greater cortisol amplitude (β = 0.43, p = 0.003). Findings suggest that certain chrononutrition components, particularly eating window and breakfast skipping have a significant influence on maternal melatonin and cortisol rhythm. Dietary intervention targeting these characteristics may be useful in maintaining maternal circadian rhythm.
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Affiliation(s)
- Ai Ni Teoh
- Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia
| | - Satvinder Kaur
- Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia,*Correspondence: Satvinder Kaur,
| | - Siti Raihanah Shafie
- Department of Nutrition, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Nurul Husna Mohd Shukri
- Department of Nutrition, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Normina Ahmad Bustami
- Faculty of Medicine and Health Sciences, School of Healthy Aging, Medical Aesthetics and Regenerative Medicine, UCSI University, Kuala Lumpur, Malaysia
| | - Masaki Takahashi
- Institute for Liberal Arts, Tokyo Institute of Technology, Tokyo, Japan
| | - Shigenobu Shibata
- Department of Electrical Engineering and Biosciences, School of Advanced Engineering and Sciences, Waseda University, Tokyo, Japan
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Huang XX, Jiang XM, Zheng QX, Chen XQ. The association between circadian rhythm of cortisol and shift work regularity among midwives-A multicenter study in Southeast China. Front Public Health 2022; 10:965872. [PMID: 36238237 PMCID: PMC9552840 DOI: 10.3389/fpubh.2022.965872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/05/2022] [Indexed: 01/24/2023] Open
Abstract
Objective This article aims to explore the association between the trends of cortisol rhythm and the regularity of shift work among midwives. Methods Midwives from six Southeast Chinese hospitals were recruited through cluster sampling in a multi-center cross-sectional study. Urine samples were collected half an hour after waking up, at 11:00, 19:00, and 23:00 on two consecutive days in a longitudinal cohort. The urinary cortisol was assayed by the chemiluminescence method. Results A total of 86 midwives were included in this study, contributing 688 cortisol samples. The midwives displayed a circadian rhythm in cortisol secretion, with zeniths in the morning and nadirs in the evening. The trend of the first day was repeated on the second day. Although the total working hours per week of the two groups, namely the regular shift group (N = 43) and the irregular shift group (N = 43), were the same, significant main effects of groups (F = 62.569, p < 0.001), time (F = 45.304, p < 0.001), and group-by-time interaction (F = 226.695, p < 0.001) were indicated through linear mixed models. The main effect of day was not statistically significant, with F = 0.105 and p = 0.746. The fluctuation range of cortisol curve in the group with irregular schedules was slightly lower than that in the group with regular schedules. Conclusion Our results may indicate that cortisol was more inhibited in midwives with irregular shift patterns than those with regular shift patterns. It is necessary to further study the relationship between cortisol rhythm and patterns of midwives' shifts in future so as to lay a foundation for hospital managers to develop a more reasonable scheduling system for midwives with the further purpose to minimize their occupational fatigue and ensure the safety of mothers and infants.
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Jensen MA, Nielsen HB, Sallinen M, Kristiansen J, Hansen ÅM, Garde AH. Self-Reported Sleepiness after 2, 4, and 7 Consecutive Night Shifts and Recovery Days in Danish Police Officers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:10527. [PMID: 36078243 PMCID: PMC9518407 DOI: 10.3390/ijerph191710527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Night shift work often implies shorter sleep duration and this can lead to sleepiness, which has been associated with an increased risk of accidents and injuries. The aim is to study how the number of consecutive night shifts affects self-reported sleepiness. PARTICIPANTS AND METHODS The study was a quasi-experimental, within-subject crossover study with 73 police officers. Three work schedules of two, four, and seven consecutive night shifts followed by the same number of recovery days, i.e., days worked or days off, was performed by all participants. Sleepiness was self-reported using the Karolinska sleepiness scale (KSS) every fourth hour on the last night shift and the last recovery day in each sequence. RESULTS We observed differences in the level of sleepiness between recovery days and night shift days but no differences in the pattern of sleepiness levels on night shift days in the different work schedules. The highest levels of KSS were observed before bedtime (at 07:00 after a night shift and 23:00 on a recovery day). CONCLUSION The number of consecutive night shifts did not affect the self-reported levels of self-reported sleepiness among Danish police officers.
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Affiliation(s)
- Marie Aarrebo Jensen
- The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
| | - Helena Breth Nielsen
- The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
| | - Mikael Sallinen
- Finnish Institute of Occupational Health, 00032 Helsinki, Finland
| | - Jesper Kristiansen
- The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
| | - Åse Marie Hansen
- The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
- Section of Social Medicine, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
| | - Anne Helene Garde
- The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
- Section of Social Medicine, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
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Archer SN, Möller-Levet CS, Laing EE, Dijk DJ. Mistimed sleep and waking activity in humans disrupts glucocorticoid signalling transcripts and SP1, but not plasma cortisol rhythms. Front Physiol 2022; 13:946444. [PMID: 36060675 PMCID: PMC9428761 DOI: 10.3389/fphys.2022.946444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/29/2022] [Indexed: 12/05/2022] Open
Abstract
Cortisol is a robust circadian signal that synchronises peripheral circadian clocks with the central clock in the suprachiasmatic nucleus via glucocorticoid receptors that regulate peripheral gene expression. Misalignment of the cortisol rhythm with the sleep–wake cycle, as occurs in shift work, is associated with negative health outcomes, but underlying molecular mechanisms remain largely unknown. We experimentally induced misalignment between the sleep–wake cycle and melatonin and cortisol rhythms in humans and measured time series blood transcriptomics while participants slept in-phase and out-of-phase with the central clock. The cortisol rhythm remained unchanged, but many glucocorticoid signalling transcripts were disrupted by mistimed sleep. To investigate which factors drive this dissociation between cortisol and its signalling pathways, we conducted bioinformatic and temporal coherence analyses. We found that glucocorticoid signalling transcripts affected by mistimed sleep were enriched for binding sites for the transcription factor SP1. Furthermore, changes in the timing of the rhythms of SP1 transcripts, a major regulator of transcription, and changes in the timing of rhythms in transcripts of the glucocorticoid signalling pathways were closely associated. Associations between the rhythmic changes in factors that affect SP1 expression and its activity, such as STAT3, EP300, HSP90AA1, and MAPK1, were also observed. We conclude that plasma cortisol rhythms incompletely reflect the impact of mistimed sleep on glucocorticoid signalling pathways and that sleep–wake driven changes in SP1 may mediate disruption of these pathways. These results aid understanding of mechanisms by which mistimed sleep affects health.
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Affiliation(s)
- Simon N. Archer
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- *Correspondence: Simon N. Archer,
| | - Carla S. Möller-Levet
- Bioinformatics Core Facility, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Emma E. Laing
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, United Kingdom
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Burek K, Rabstein S, Kantermann T, Vetter C, Rotter M, Wang-Sattler R, Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Night work, chronotype and cortisol at awakening in female hospital employees. Sci Rep 2022; 12:6525. [PMID: 35443768 PMCID: PMC9021274 DOI: 10.1038/s41598-022-10054-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/25/2022] [Indexed: 11/09/2022] Open
Abstract
To examine the effect of night shift on salivary cortisol at awakening (C1), 30 min later (C2), and on the cortisol awakening response (CAR, the difference between C2 and C1). We compared shift and non-shift workers with a focus on the impact of worker chronotype. Our study included 66 shift-working females (mean age = 37.3 years, SD = 10.2) and 21 non-shift working females (mean age = 47.0 years, SD = 8.9). The shift workers collected their saliva samples at C1 and C2 on each two consecutive day shifts and night shifts. Non-shift workers collected their samples on two consecutive day shifts. We applied linear mixed-effects models (LMM) to determine the effect of night shift on CAR and log-transformed C1 and C2 levels. LMMs were stratified by chronotype group. Compared to non-shift workers, shift workers before day shifts (i.e. after night sleep) showed lower cortisol at C1 (exp [Formula: see text]=0.58, 95% CI 0.42, 0.81) but not at C2. In shift workers, the CARs after night shifts (i.e. after day sleep) were lower compared to CARs before day shifts ([Formula: see text]= - 11.07, 95% CI - 15.64, - 6.50). This effect was most pronounced in early chronotypes (early: [Formula: see text]= - 16.61, 95% CI - 27.87, - 5.35; intermediate: [Formula: see text]= - 11.82, 95% CI - 18.35, - 5.29; late: [Formula: see text]= - 6.27, 95% CI - 14.28, 1.74). Chronotype did not modify the association between night shift and CAR. In our population of shift workers, there was a mismatch between time of waking up and their natural cortisol peak at waking up (CAR) both during day and night shift duties.
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Affiliation(s)
- Katarzyna Burek
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany.
| | - Sylvia Rabstein
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Thomas Kantermann
- Institute for Labor and Personnel (IAP), University of Applied Sciences for Economics and Management (FOM), Essen, Germany.,SynOpus, Bochum, Germany
| | - Céline Vetter
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.,XIMES GmbH, Vienna, Austria
| | - Markus Rotter
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Rui Wang-Sattler
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Martin Lehnert
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Dirk Pallapies
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Karl-Heinz Jöckel
- Institute for Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
| | - Thomas Brüning
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Thomas Behrens
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
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11
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Tabarin A, Assié G, Barat P, Bonnet F, Bonneville JF, Borson-Chazot F, Bouligand J, Boulin A, Brue T, Caron P, Castinetti F, Chabre O, Chanson P, Corcuff JB, Cortet C, Coutant R, Dohan A, Drui D, Espiard S, Gaye D, Grunenwald S, Guignat L, Hindie E, Illouz F, Kamenicky P, Lefebvre H, Linglart A, Martinerie L, North MO, Raffin-Samson ML, Raingeard I, Raverot G, Raverot V, Reznik Y, Taieb D, Vezzosi D, Young J, Bertherat J. Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome. ANNALES D'ENDOCRINOLOGIE 2022; 83:119-141. [PMID: 35192845 DOI: 10.1016/j.ando.2022.02.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.
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Affiliation(s)
- Antoine Tabarin
- Service Endocrinologie, Diabète et Nutrition, Université, Hôpital Haut-Leveque CHU de Bordeaux, 33604 Pessac, France.
| | - Guillaume Assié
- Centre de Référence Maladies Rares de la Surrénale (CRMRS), Service d'Endocrinologie, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
| | - Pascal Barat
- Unité d'Endocrinologie-Diabétologie-Gynécologie-Obésité Pédiatrique, Hôpital des Enfants CHU Bordeaux, Bordeaux, France
| | - Fidéline Bonnet
- UF d'Hormonologie Hôpital Cochin, Université de Paris, Institut Cochin Inserm U1016, CNRS UMR8104, Paris, France
| | | | - Françoise Borson-Chazot
- Fédération d'Endocrinologie, Hôpital Louis-Pradel, Hospices Civils de Lyon, INSERM U1290, Université Lyon1, 69002 Lyon, France
| | - Jérôme Bouligand
- Faculté de Médecine Paris-Saclay, Unité Inserm UMRS1185 Physiologie et Physiopathologie Endocriniennes, Paris, France
| | - Anne Boulin
- Service de Neuroradiologie, Hôpital Foch, 92151 Suresnes, France
| | - Thierry Brue
- Aix-Marseille Université, Institut National de la Recherche Scientifique (INSERM) U1251, Marseille Medical Genetics, Marseille, France; Assistance publique-Hôpitaux de Marseille, Service d'Endocrinologie, Hôpital de la Conception, Centre de Référence Maladies Rares HYPO, 13005 Marseille, France
| | - Philippe Caron
- Service d'Endocrinologie et Maladies Métaboliques, Pôle Cardiovasculaire et Métabolique, CHU Larrey, 24, chemin de Pouvourville, TSA 30030, 31059 Toulouse cedex, France
| | - Frédéric Castinetti
- Aix-Marseille Université, Institut National de la Recherche Scientifique (INSERM) U1251, Marseille Medical Genetics, Marseille, France; Assistance publique-Hôpitaux de Marseille, Service d'Endocrinologie, Hôpital de la Conception, Centre de Référence Maladies Rares HYPO, 13005 Marseille, France
| | - Olivier Chabre
- Université Grenoble Alpes, UMR 1292 INSERM-CEA-UGA, Endocrinologie, CHU Grenoble Alpes, 38000 Grenoble, France
| | - Philippe Chanson
- Université Paris-Saclay, Inserm, Physiologie et Physiopathologie Endocriniennes, Assistance publique-Hôpitaux de Paris, Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse HYPO, Le Kremlin-Bicêtre, France
| | - Jean Benoit Corcuff
- Laboratoire d'Hormonologie, Service de Médecine Nucléaire, CHU Bordeaux, Laboratoire NutriNeuro, UMR 1286 INRAE, Université de Bordeaux, Bordeaux, France
| | - Christine Cortet
- Service d'Endocrinologie, Diabétologie, Métabolisme et Nutrition, CHU de Lille, Lille, France
| | - Régis Coutant
- Service d'Endocrinologie Pédiatrique, CHU Angers, Centre de Référence, Centre Constitutif des Maladies Rares de l'Hypophyse, CHU Angers, Angers, France
| | - Anthony Dohan
- Department of Radiology A, Hôpital Cochin, AP-HP, 75014 Paris, France
| | - Delphine Drui
- Service Endocrinologie-Diabétologie et Nutrition, l'institut du Thorax, CHU Nantes, 44092 Nantes cedex, France
| | - Stéphanie Espiard
- Service d'Endocrinologie, Diabétologie, Métabolisme et Nutrition, INSERM U1190, Laboratoire de Recherche Translationnelle sur le Diabète, 59000 Lille, France
| | - Delphine Gaye
- Service de Radiologie, Hôpital Haut-Lêveque, CHU de Bordeaux, 33604 Pessac, France
| | - Solenge Grunenwald
- Service d'Endocrinologie, Hôpital Larrey, CHU Toulouse, Toulouse, France
| | - Laurence Guignat
- Centre de Référence Maladies Rares de la Surrénale (CRMRS), Service d'Endocrinologie, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
| | - Elif Hindie
- Service de Médecine Nucléaire, CHU de Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Frédéric Illouz
- Centre de Référence Maladies Rares de la Thyroïde et des Récepteurs Hormonaux, Service Endocrinologie-Diabétologie-Nutrition, CHU Angers, 49933 Angers cedex 9, France
| | - Peter Kamenicky
- Assistance publique-Hôpitaux de Paris, Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse, 94275 Le Kremlin-Bicêtre, France
| | - Hervé Lefebvre
- Service d'Endocrinologie, Diabète et Maladies Métaboliques, CHU de Rouen, Rouen, France
| | - Agnès Linglart
- Paris-Saclay University, AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR, and Platform of Expertise for Rare Disorders, INSERM, Physiologie et Physiopathologie Endocriniennes, Bicêtre Paris-Saclay Hospital, Le Kremlin-Bicêtre, France
| | - Laetitia Martinerie
- Service d'Endocrinologie Pédiatrique, CHU Robert-Debré, AP-HP, Paris, France; Université de Paris, Paris, France
| | - Marie Odile North
- Service de Génétique et Biologie Moléculaire, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
| | - Marie Laure Raffin-Samson
- Service d'Endocrinologie Nutrition, Hôpital Ambroise-Paré, GHU Paris-Saclay, AP-HP Boulogne, EA4340, Université de Versailles-Saint-Quentin, Paris, France
| | - Isabelle Raingeard
- Maladies Endocriniennes, Hôpital Lapeyronie, CHU Montpellier, Montpellier, France
| | - Gérald Raverot
- Fédération d'Endocrinologie, Centre de Référence Maladies Rares Hypophysaires, "Groupement Hospitalier Est", Hospices Civils de Lyon, Lyon, France
| | - Véronique Raverot
- Hospices Civils de Lyon, LBMMS, Centre de Biologie Est, Service de Biochimie et Biologie Moléculaire, 69677 Bron cedex, France
| | - Yves Reznik
- Department of Endocrinology and Diabetology, CHU Côte-de-Nacre, 14033 Caen cedex, France; University of Caen Basse-Normandie, Medical School, 14032 Caen cedex, France
| | - David Taieb
- Aix-Marseille Université, CHU La Timone, AP-HM, Marseille, France
| | - Delphine Vezzosi
- Service d'Endocrinologie, Hôpital Larrey, CHU Toulouse, Toulouse, France
| | - Jacques Young
- Assistance publique-Hôpitaux de Paris, Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse, 94275 Le Kremlin-Bicêtre, France
| | - Jérôme Bertherat
- Centre de Référence Maladies Rares de la Surrénale (CRMRS), Service d'Endocrinologie, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
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12
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Pundir M, Papagerakis S, De Rosa MC, Chronis N, Kurabayashi K, Abdulmawjood S, Prince MEP, Lobanova L, Chen X, Papagerakis P. Emerging biotechnologies for evaluating disruption of stress, sleep, and circadian rhythm mechanism using aptamer-based detection of salivary biomarkers. Biotechnol Adv 2022; 59:107961. [DOI: 10.1016/j.biotechadv.2022.107961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/30/2022] [Accepted: 04/09/2022] [Indexed: 12/26/2022]
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13
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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: 86] [Impact Index Per Article: 28.7] [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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14
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Cortisol and shiftwork: A scoping review. Sleep Med Rev 2021; 64:101581. [DOI: 10.1016/j.smrv.2021.101581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/20/2022]
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15
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Honn KA. 24 th international symposium on shiftwork and working time: innovations in research and practice improving shiftworker health & safety. Chronobiol Int 2021; 37:1273-1282. [PMID: 33957058 DOI: 10.1080/07420528.2020.1831719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Kimberly A Honn
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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16
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Nie J, Zhou T, Chen Z, Dang W, Jiao F, Zhan J, Chen Y, Chen Y, Pan Z, Kang X, Wang Y, Wang Q, Tang Y, Dong W, Zhou S, Ma Y, Yu X, Zhang G, Shen B. The effects of dynamic daylight-like light on the rhythm, cognition, and mood of irregular shift workers in closed environment. Sci Rep 2021; 11:13059. [PMID: 34158564 PMCID: PMC8219698 DOI: 10.1038/s41598-021-92438-y] [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: 02/08/2021] [Accepted: 06/10/2021] [Indexed: 02/05/2023] Open
Abstract
Shift workers are mostly suffered from the disruption of circadian rhythm and health problems. In this study, we designed proper light environment to maintain stable circadian rhythm, cognitive performance, and mood status of shift workers. We used five-channel light-emitting diodes to build up the dynamic daylight-like light environment. The illuminance, correlated color temperature, and circadian action factor of light were tunable in the ranges of 226 to 678 lx, 2680 to 7314 K, and 0.32 to 0.96 throughout the day (5:30 to 19:40). During the nighttime, these parameters maintained about 200 lx, 2700 K, and 0.32, respectively. In this light environment, three subjects had engaged in shift work for 38 consecutive days. We measured plasma melatonin, activity counts, continuous performance tests, and visual analogue scale on mood to assess the rhythm, cognitive performance, and mood of subjects. After 38-day shift work, the subjects' peak melatonin concentration increased significantly. Their physiological and behavioral rhythms maintained stable. Their cognitive performance improved significantly after night work, compared with that before night work. Their mood status had no significant change during the 38-day shift work. These results indicated that the light environment was beneficial to maintain circadian rhythm, cognitive performance and mood status during long-term shift work in closed environment.
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Affiliation(s)
- Jingxin Nie
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Tianhang Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Zhizhong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China.
| | - Weimin Dang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China.
| | - Fei Jiao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China
| | - Jinglin Zhan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yifan Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yiyong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Zuojian Pan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Xiangning Kang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yongzhi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Qi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Yan Tang
- Department of Physical Education, Peking University, Beijing, 100871, China
| | - Wentian Dong
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Shuzhe Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Yantao Ma
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Xin Yu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Guoyi Zhang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Bo Shen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
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Abstract
The study aimed to explore chronotype-specific effects of two versus four consecutive morning or night shifts on sleep-wake behavior. Sleep debt and social jetlag (a behavioral proxy of circadian misalignment) were estimated from sleep diary data collected for 5 weeks in a within-subject field study of 30 rotating night shift workers (29.9 ± 7.3 years, 60% female). Mixed models were used to examine whether effects of shift sequence length on sleep are dependent on chronotype, testing the interaction between sequence length (two vs. four) and chronotype (determined from sleep diaries). Analyses of two versus four morning shifts showed no significant interaction effects with chronotype. In contrast, increasing the number of night shifts from two to four increased sleep debt in early chronotypes, but decreased sleep debt in late types, with no change in intermediate ones. In early types, the higher sleep debt was due to accumulated sleep loss over four night shifts. In late types, sleep duration did not increase over the course of four night shifts, so that adaptation is unlikely to explain the observed lower sleep debt. Late types instead had increased sleep debt after two night shifts, which was carried over from two preceding morning shifts in this schedule. Including naps did not change the findings. Social jetlag was unaffected by the number of consecutive night shifts. Our results suggest that consecutive night shifts should be limited in early types. For other chronotypes, working four night shifts might be a beneficial alternative to working two morning and two night shifts. Studies should record shift sequences in rotating schedules.
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Affiliation(s)
- Dorothee Fischer
- Department of Sleep and Human Factors, Institute for Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Till Roenneberg
- Institute of Medical Psychology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Céline Vetter
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
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Abstract
Disordered sleep impairs neurocognitive performance, and is now recognized to cause metabolic ill-health. This review assesses the nascent relationship between insufficient, misaligned, and disrupted sleep with andrological health. High-quality cohort studies show a reduced sperm count in men with sleep disturbances. Well-designed interventional studies show a reduction in testosterone with sleep restriction. Studies of long-term shift workers show no effect of misaligned sleep on mean testosterone concentrations. Men with obstructive sleep apnea (OSA) and more severe hypoxemia have lower testosterone levels, although it is unknown if this relationship is entirely explained by concomitant obesity, or is reversible. Nevertheless, erectile dysfunction, which is common in men with OSA, is clinically improved when OSA is properly treated. Few studies manipulating sleep have been performed in older men, in whom the accumulation of sleep disturbances over decades of life may contribute to age-related illnesses. Improving sleep could ameliorate the development of these disorders.
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Affiliation(s)
- Nora A O'Byrne
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Fiona Yuen
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Warda Niaz
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Peter Y Liu
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA.,Department of Medicine, Division of Endocrinology, David Geffen School of Medicine at UCLA
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Lee S, Park JB, Lee KJ, Ham S, Jeong I. Effects of work organization on the occurrence and resolution of sleep disturbances among night shift workers: a longitudinal observational study. Sci Rep 2021; 11:5499. [PMID: 33750873 PMCID: PMC7970909 DOI: 10.1038/s41598-021-85017-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/23/2021] [Indexed: 11/09/2022] Open
Abstract
This study aimed to investigate the association between work organization and the trajectories of insomnia patterns among night shift workers in a hospital. The health examination data of hospital workers, recorded from January 2014 to December 2018, were collected; 6765 records of 2615 night shift workers were included. Insomnia was defined as a score of ≥ 15 on the Insomnia Severity Index (ISI). Participants were categorized into five groups according to insomnia patterns derived from the analysis of their ISI scores. Work organization and socio-demographic characteristics were also investigated. Generalized estimating equation models and linear mixed models were constructed to analyze the longitudinal data. Of the total participants, 53.0% reported insomnia at least once during the follow-up period. The lack of nap opportunities and work-time control was associated with the occurrence of insomnia, whereas more than 5 years of shift work experience was related to the resolution of insomnia. All work-related factors were significantly related to insomnia risk; however, the effects were not significant in the sustained insomnia group. Although sleep problems are inevitable in night shift workers, well-designed work schedules and better work organization can help reduce the occurrence of insomnia among them.
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Affiliation(s)
- Seungho Lee
- Department of Occupational and Environmental Medicine, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon, 16499, South Korea
| | - Jae Bum Park
- Department of Occupational and Environmental Medicine, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon, 16499, South Korea
| | - Kyung-Jong Lee
- Department of Occupational and Environmental Medicine, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon, 16499, South Korea
| | - Seunghon Ham
- Department of Occupational and Environmental Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, 21565, South Korea
| | - Inchul Jeong
- Department of Occupational and Environmental Medicine, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon, 16499, South Korea.
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20
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Garde AH, Begtrup L, Bjorvatn B, Bonde JP, Hansen J, Hansen ÅM, Härmä M, Jensen MA, Kecklund G, Kolstad HA, Larsen AD, Lie JA, Moreno CR, Nabe-Nielsen K, Sallinen M. How to schedule night shift work in order to reduce health and safety risks. Scand J Work Environ Health 2020; 46:557-569. [PMID: 32895725 PMCID: PMC7737811 DOI: 10.5271/sjweh.3920] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Indexed: 12/22/2022] Open
Abstract
Objectives This discussion paper aims to provide scientifically based recommendations on night shift schedules, including consecutive shifts, shift intervals and duration of shifts, which may reduce health and safety risks. Short-term physiological effects in terms of circadian disruption, inadequate sleep duration and quality, and fatigue were considered as possible links between night shift work and selected health and safety risks, namely, cancer, cardio-metabolic disease, injuries, and pregnancy-related outcomes. Method In early 2020, 15 experienced shift work researchers participated in a workshop where they identified relevant scientific literature within their main research area. Results Knowledge gaps and possible recommendations were discussed based on the current evidence. The consensus was that schedules which reduce circadian disruption may reduce cancer risk, particularly for breast cancer, and schedules that optimize sleep and reduce fatigue may reduce the occurrence of injuries. This is generally achieved with fewer consecutive night shifts, sufficient shift intervals, and shorter night shift duration. Conclusions Based on the limited, existing literature, we recommend that in order to reduce the risk of injuries and possibly breast cancer, night shift schedules have: (i) ≤3 consecutive night shifts; (ii) shift intervals of ≥11 hours; and (iii) ≤9 hours shift duration. In special cases - eg, oil rigs and other isolated workplaces with better possibilities to adapt to daytime sleep - additional or other recommendations may apply. Finally, to reduce risk of miscarriage, pregnant women should not work more than one night shift in a week.
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Affiliation(s)
- Anne Helene Garde
- The National Research Centre for the Working Environment, Lerso Parkallé 105, DK-2100 Copenhagen, Denmark.
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Nie J, Zhou T, Chen Z, Dang W, Jiao F, Zhan J, Chen Y, Chen Y, Pan Z, Kang X, Wang Y, Wang Q, Dong W, Zhou S, Yu X, Zhang G, Shen B. Investigation on entraining and enhancing human circadian rhythm in closed environments using daylight-like LED mixed lighting. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 732:139334. [PMID: 32438188 DOI: 10.1016/j.scitotenv.2020.139334] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Humans can undergo circadian disruption and misalignment when living in closed environments without sufficient daylight. Therefore, it is of great significance to investigate the effects of artificial light on the circadian rhythm. In this work, the red, green, blue, warm white, and cool white (RGBWW) five-channel light-emitting diodes (LEDs) were fabricated as the only light sources in the closed environment. The LED mixed lighting showed a high color rendering index (CRI) all the time. During the day, the light simulated the daylight and increased the tunability of the circadian action factor (CAF) and correlated color temperature (CCT). At night, it maintained low CAF and CCT. Three subjects did irregular shift work in the closed environment for 38 days. Their plasma melatonin and daily activity were measured to assess the circadian rhythm. After 38 days, the subjects' peak melatonin times did not shift significantly (p = 0.676), while their peak melatonin concentrations increased apparently (p = 0.005). The start times of the least active 5-h period (L5) in one day fluctuated in a small range. The standard deviation (SD) was <15.11 min in most times. These results demonstrated that the subjects' rhythms maintained stable and were enhanced. The periods of circular cross-correlation between activity and CAF oscillated around 24 h (SD = 15.4 min), indicating the entrainment of light on the stable 24-h rhythm. It was concluded that the daylight-like LED lighting effectively entrained and enhanced the circadian rhythm in the closed environment.
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Affiliation(s)
- Jingxin Nie
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Tianhang Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Zhizhong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
| | - Weimin Dang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Fei Jiao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China; State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Jinglin Zhan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yifan Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yiyong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Zuojian Pan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Xiangning Kang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yongzhi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan 523808, Guangdong, China
| | - Qi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan 523808, Guangdong, China
| | - Wentian Dong
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Shuzhe Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Xin Yu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Guoyi Zhang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China; Dongguan Institute of Optoelectronics, Peking University, Dongguan 523808, Guangdong, China
| | - Bo Shen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
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Aarrebo Jensen M, Kjærgaard JB, Petersen JD, Hansen ÅM, Kristiansen J, Garde AH. The urinary 6-sulfatoxymelatonin level after three different work schedules with 2, 4 and 7 consecutive night shifts among Danish police officers. Chronobiol Int 2020; 37:1400-1403. [DOI: 10.1080/07420528.2020.1807560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Marie Aarrebo Jensen
- Department of Psychosocial work environment, National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Julie Boye Kjærgaard
- Department of Psychosocial work environment, National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Jindong Ding Petersen
- Research Unit for General Practice, Department of Public Health, University of Southern Denmark, Odense, Denmark
- Research Unit for General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Åse Marie Hansen
- Department of Psychosocial work environment, National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Kristiansen
- Department of Psychosocial work environment, National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Anne Helene Garde
- Department of Psychosocial work environment, National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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Milliard B. Utilization and Impact of Peer-Support Programs on Police Officers' Mental Health. Front Psychol 2020; 11:1686. [PMID: 32765375 PMCID: PMC7381167 DOI: 10.3389/fpsyg.2020.01686] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/22/2020] [Indexed: 11/15/2022] Open
Abstract
Police officer suicide rates hit an all-time high in the province of Ontario, Canada, in 2018. Sadly, this statistic is somewhat unsurprising, as research has shown that police officers suffer from higher rates of mental health disorder diagnoses compared to the general public. One key reason for the elevated levels of suicide and other mental health issues among police officers is believed to stem from the stigma associated with seeking help. In an attempt to address these serious issues, Ontario’s police services have begun to create internal peer support programs as a way of supporting their members. The present research explores the experiences of police officers serving as peer-support team members, particularly with regards to the impacts of peer support. In addition, this research also examines the importance of discussing shared experiences regarding a lack of standardized procedures for the administration and implementation of peer support in relation to the Policy Feedback Theory. The Policy Feedback Theory (PFT) posits that, when a policy becomes established and resources are devoted to programs, it helps structure current activity. This study utilized a phenomenological, qualitative approach, with data collection consisting of face-to-face interviews with nine police officers serving on the York Regional Police’s peer-support team. The findings revealed that peer support is more than just a “conversation”; rather, it suggests to contribute to enhancing mental health literacy among police officers, and it significantly contributes to stigma reduction. The findings also revealed that internal policy demonstrated an organizational commitment to mental health and peer-support, and that a provincial standard is necessary to ensure best practices and risk management in the creation and maintenance of peer-support programs.
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Affiliation(s)
- Beth Milliard
- York Regional Police, Aurora, ON, Canada.,Criminal Justice, Walden University, Minneapolis, MN, United States
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Larsen AD, Rugulies R, Hansen J, Kolstad HA, Hansen ÅM, Hannerz H, Garde AH. Night work and risk of ischaemic heart disease and anti-hypertensive drug use: a cohort study of 145 861 Danish employees. Eur J Public Health 2020; 30:259-264. [PMID: 31722388 PMCID: PMC7183362 DOI: 10.1093/eurpub/ckz189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Ischaemic heart disease (IHD) and hypertension are leading causes of mortality and night work has been suspected as a risk factor. Meta-analyses and previous studies are often limited by power and various definitions of exposure and outcomes. This study aimed to investigate if night work increases the risk of IHD or anti-hypertensive drug usage in a large cohort of Danish employees. Methods Individual participant data on night work were drawn from the Danish Labour Force Survey (1999–2013). We included 145 861 participants (53% men) 21–59 years of age working 32 h or more per week. Participants with diagnosis or drug use in the year prior to baseline were excluded. Data on outcomes were obtained from nationwide health registers. Using Poisson regression we analyzed incidence rates of the outcomes as functions of night work adjusted for relevant covariates. Results We observed 3635 cases of IHD and 20 648 cases used anti-hypertensive drugs. When examining main effects the association of night work with drug use was estimated at rate ratio (RR): 1.05 (95% CI: 1.01–1.09). A sensitivity analysis suggested a dose-response association. The association of night work with IHD was estimated at RR: 1.08 (95% CI: 0.98–1.19). Overall likelihood ratio test showed no statistically significant associations between night work and IHD or drug use when including interactions with sex and socioeconomic status. Conclusions Night work was associated with an increased risk of anti-hypertensive drug use. Small estimates suggested a dose-response association. No statistically significant association between night work and IHD were found.
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Affiliation(s)
- Ann D Larsen
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Reiner Rugulies
- The National Research Centre for the Working Environment, Copenhagen, Denmark.,Department of Public Health, University of Copenhagen, Copenhagen, Denmark.,Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Johnni Hansen
- Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Henrik A Kolstad
- Department of Occupational Medicine, Danish Ramazzini Centre, University of Aarhus, Aarhus, Denmark
| | - Åse Marie Hansen
- The National Research Centre for the Working Environment, Copenhagen, Denmark.,Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Harald Hannerz
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Anne Helene Garde
- The National Research Centre for the Working Environment, Copenhagen, Denmark.,Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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26
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Liu PY. A Clinical Perspective of Sleep and Andrological Health: Assessment, Treatment Considerations, and Future Research. J Clin Endocrinol Metab 2019; 104:4398-4417. [PMID: 31042277 PMCID: PMC6735730 DOI: 10.1210/jc.2019-00683] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 04/25/2019] [Indexed: 12/29/2022]
Abstract
CONTEXT Sleep that is insufficient, misaligned, or disrupted causes hypersomnolence and neuropsychological deficits, adversely affects cardiometabolic health, and is increasingly recognized to impair other biological processes that lead to conditions important to men, such as hypogonadism, erectile dysfunction, and infertility. EVIDENCE ACQUISITION Literature review from 1970 to December 2018. EVIDENCE SYNTHESIS High-quality and complementary epidemiological and interventional studies establish that abnormal sleep is associated with increased mortality, hypertension, and other cardiometabolic disorders (insufficient, disrupted, and misaligned sleep), as well as reduced fecundity and total sperm count (insufficient sleep), erectile dysfunction (disrupted sleep), and low testosterone (both). Circadian misalignment shifts the peak of testosterone's diurnal rhythm to occur soon after waking up, irrespective of the biological clock time, but it does not change the mean concentration. Preliminary studies show that extending sleep in individuals who are chronically sleep deprived may become a strategy to reduce insulin resistance and hypertension. Continuous positive airway pressure therapy can improve erectile function, and possibly systemic testosterone exposure, but only when used adherently by men with obstructive sleep apnea. Both high-dose and replacement-dose testosterone therapies modestly worsen sleep-disordered breathing, but they also improve cardiometabolic function and sexual desire. Persistence of either the adverse or beneficial outcomes over the longer term requires further investigation. CONCLUSIONS Sleep is increasingly recognized to be essential for healthy living. Establishing the effect of abnormal sleep, and of improving sleep, on andrological issues of prime interest to men will promote prioritization of sleep, and may thereby improve overall long-term health outcomes.
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Affiliation(s)
- Peter Y Liu
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California
- David Geffen School of Medicine at UCLA, Los Angeles, California
- Correspondence and Reprint Requests: Peter Y. Liu, PhD, Division of Endocrinology and Metabolism, Department of Medicine, Harbor UCLA Medical Center and Los Angeles Biomedical Research Institute, 1124 West Carson Street, Box 446, Torrance, California 90502. E-mail:
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Ni W, Liu K, Hou G, Pan C, Wu S, Zheng J, Cao J, Chen Q, Huang X. Diurnal variation in sperm DNA fragmentation: analysis of 11,382 semen samples from two populations and in vivo animal experiments. Chronobiol Int 2019; 36:1455-1463. [PMID: 31418296 DOI: 10.1080/07420528.2019.1649275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Circadian rhythms have been found in some reproductive functions phenotypes but remain unclear for sperm DNA fragmentation index (DFI). The present study aims to investigate the diurnal variation of DFI in mice model and men sperm. Adult male mice were sacrificed for sperm DFI with Sperm Chromatin Structure Assay (SCSA) in 24 hours at 6 evenly distributed time points. A cosinor pattern of DFI was observed with a nadir at zeitgeber time 10 AM. In a community population with 630 semen samples collected between 8 AM and 20 PM, the temporal variation of DFI also fit a cosinor pattern with a - 343° acrophase and a nadir at 11 AM (P = .031). In a reproductive-medical-center dataset of 10752 semen samples collected between 7 AM and 11 AM, the decreasing trend of DFI was also confirmed. For the males with multiple samples, intra-individual comparison between different timepoints was performed, and each consecutive hour after 7 AM was also associated with 2.5 (95% CI: -1.0, 5.9)% lower DFI by SCSA or 4.9 (1.9, 7.8)% lower DFI by SCD. Our study reveals a daily diurnal variance in sperm DFI which may suggest a practical approach to get more qualified sperms for natural or assisted reproduction. Abbreviations: BMI, Body mass index; DFI, DNA fragmentation index; MARHCS, Male Reproductive Health in the Chongqing College Students; RMC, Reproductive Medical Center; SCD, Sperm Chromatin Dispersion; SCSA, Sperm Chromatin Structure Assay.
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Affiliation(s)
- Wuhua Ni
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou , China
| | - Kun Liu
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University) , Chongqing , China
| | - Guizhong Hou
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University) , Chongqing , China
| | - Chengshuang Pan
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou , China
| | - Suichun Wu
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou , China
| | - Jiujia Zheng
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou , China
| | - Jia Cao
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University) , Chongqing , China
| | - Qing Chen
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Army Medical University (Third Military Medical University) , Chongqing , China
| | - Xuefeng Huang
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou , China
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28
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Oldenburg M, Jensen HJ. Saliva cortisol level as a strain parameter for crews aboard merchant ships. Chronobiol Int 2019; 36:1005-1012. [PMID: 31056955 DOI: 10.1080/07420528.2019.1604540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Seafarers working in maritime settings are affected by a great number of psychosocial stressors. The testing of cortisol in saliva is a well-established method for judging the individual strain. Therefore, this study aims to assess the crews' strain on container ships on the basis of this parameter, taking occupational groups and the three voyage episodes of the vessel into account (stay at port, river passage and sea passage). One scientist accompanied 22 sea voyages and examined 304 crew members who had provided a minimum of 5 saliva samples from at least one day. Altogether, 4,073 saliva samples were collected. An evaluation of stress hormones was conducted by analyzing on the basis of groups and day profiles. The present study revealed that the average concentration of cortisol in the saliva of the examined seafarers was lower during the first hour after waking up than that of a healthy reference population. There were significant differences in the cortisol between nautical officers, deck ratings, and engine room personnel with decreasing levels (p < .001). Furthermore, the highest cortisol level was measured during port stay followed by sea passages and river passages (p = .002). After adjustment, the average level of cortisol in saliva of the whole study group was positively associated with acute shipboard stressors, namely the average current working time (p = .050) and the average number of terminals that had been served during the last 7 days (p = .008). In contrast, no association of saliva cortisol was observed with age (p = .130), smoking status (p = .436), the current stay on board of the vessel (p = .230) or with the subjective stress evoked by noise, vibration, ship motion or psychophysical demands on board. Only the deck ratings and the engine room personnel displayed a continuous decrease in the cortisol level in the daily profile (p < .001). In total, the present study revealed an association of the saliva cortisol level among the examined crew with acute shipboard stressors, the working group, and the ship's voyage episode. A reliable collection of samples over several days on board is well possible through the presence of a specially trained person on site. In maritime studies, this high level of personal effort seems to be inevitable in order to allow a differentiated judgement of the hormone stress reaction of seafarers and meet high quality standards.
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Affiliation(s)
- Marcus Oldenburg
- a Department of Maritime Medicine , Institute for Occupational and Maritime Medicine Hamburg (ZfAM), University Medical Center Hamburg-Eppendorf (UKE) , Hamburg , Germany
| | - Hans-Joachim Jensen
- a Department of Maritime Medicine , Institute for Occupational and Maritime Medicine Hamburg (ZfAM), University Medical Center Hamburg-Eppendorf (UKE) , Hamburg , Germany
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Specht IO, Hammer PEC, Flachs EM, Begtrup LM, Larsen AD, Hougaard KS, Hansen J, Hansen ÅM, Kolstad HA, Rugulies R, Garde AH, Bonde JP. Night work during pregnancy and preterm birth-A large register-based cohort study. PLoS One 2019; 14:e0215748. [PMID: 30998803 PMCID: PMC6472821 DOI: 10.1371/journal.pone.0215748] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/08/2019] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Melatonin stimulates the production of progesterone, which is essential for the maintenance of pregnancy. Since melatonin in blood is reduced due to work under illuminated conditions during night work, it has been hypothesized that night work may increase the risk of preterm birth. Previous meta-analyses have not revealed increased risk of preterm birth in women working night shifts during pregnancy. Still, these studies might have been limited by inaccurate self-reports of timing, intensity and duration of night work most likely causing bias towards the null. The aim of this is study was to investigate if the frequency and duration of night work during the first (week 1-12) and second (week 13-22) trimester of pregnancy were associated with risk of preterm birth when objective and prospective data on night work are used. METHOD In a register-based prospective cohort study, we obtained individual day-to-day information on working hours from The Danish Working Hour Database (DWHD, a payroll database including all public service employees in administrative Danish Regions from 2007-2013) and information on preterm birth from the Danish Medical Birth Registry. Night-shift was defined as at least three working hours between 23:00 and 06:00. Preterm birth was defined as giving birth during gestational weeks 23-37. Odds of preterm birth according to working night shifts were analysed by logistic regression. RESULTS We identified 16,501 pregnant women eligible for the study, of which 10,202 women (61.8%) had at least one night-shift during the first 22 gestational weeks. The risk of preterm birth was not elevated among women working night shifts compared to women working only day shifts during either the first or second trimester. Within night-shift workers, the risk was not related to the number of night shifts, the duration of night shifts, consecutive night shifts or quick returns defined as short intervals between shifts. Odds of preterm birth was not related to change of working schedule from the first to second trimester, although women changing from night shifts in the first trimester to day work only in the second trimester displayed a weak increased odds of preterm birth (OR 1.21, 95%CI 0.98-1.49) compared to women working night shifts in both trimesters. CONCLUSION Our results, which are without bias from self-report of either exposure or outcome, are in line with the results of previous meta-analyses. Due to the detailed information on hours worked during pregnancy, we were able to investigate several dimensions of night work not previously investigated, of which none were associated with elevated risk of preterm birth.
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Affiliation(s)
- Ina Olmer Specht
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- The Parker Institute, Bispebjerg and Frederiksberg Hospital, Frederiksberg, Denmark
| | - Paula E. C. Hammer
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Esben M. Flachs
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Luise M. Begtrup
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Ann D. Larsen
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Karin S. Hougaard
- The National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Johnni Hansen
- Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Åse M. Hansen
- The National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Henrik A. Kolstad
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Reiner Rugulies
- The National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
- Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Anne Helene Garde
- The National Research Centre for the Working Environment, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Jens Peter Bonde
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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30
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Garde AH, Harris A, Vedaa Ø, Bjorvatn B, Hansen J, Hansen ÅM, Kolstad HA, Koskinen A, Pallesen S, Ropponen A, Härmä MI. Working hour characteristics and schedules among nurses in three Nordic countries - a comparative study using payroll data. BMC Nurs 2019; 18:12. [PMID: 30962763 PMCID: PMC6438001 DOI: 10.1186/s12912-019-0332-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/26/2019] [Indexed: 01/14/2023] Open
Abstract
Background Organisation of working hour schedules in the Northern European countries are rather similar. EU countries are obliged to adopt national legislation regarding duration of weekly working hours and rest periods. Yet, working hour characteristics and schedules are likely to differ with respect to starting times and duration depending e.g. on culture and tradition. Yet, very little is known about potential differences between shifts and schedules across countries among nursing personel. This knowledge is relevant, since the potential differences in working hour characteristics may influence and possibly explain some of the differences observed in studies of health and safety.The aim of the study was to compare characteristics of working hours and work schedules among nursing personel in three Nordic countries: Denmark, Finland and Norway. Methods The study populations included nursing personnel holding a ≥ 50% position at public hospitals in Denmark (n = 63,678), Finland (n = 18,257) or Norway (n = 1538) in 2013. Objective payroll based registry data with information on daily starting and ending times were used to compare working hour characteristics e.g. starting time, duration of shift, and quick returns (< 11 h between two shifts), as well as work schedules e.g. permanent or 3-shift work between the three countries. Results Night shifts generally started earlier and lasted longer in Finland (10-11 h starting at 20:00-22:59) than in Norway (10 h starting at 21:00-21:59) and in Denmark (8 h starting at 23:00-23:59). Very long shifts (≥12 h) were more common in Denmark (12%) compared to Finland (8%) and Norway (3%). More employees had many (> 13/year) quick returns in Norway (64%) and Finland (47%) compared to Denmark (16%). The frequency of 3-shift rotation workers was highest in Norway (41%) and lower in Denmark (22%) and Finland (22%). There were few differences across the countries in terms of early morning shifts and (very) long weekly working hours. Conclusion Despite similar distribution of operational hours among nurses in the three countries, there were differences in working hour characteristics and the use of different types of work schedules. The observed differences may affect health and safety.
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Affiliation(s)
- Anne Helene Garde
- The National Research Center for the Working Environment, DK-2100 Copenhagen, Denmark.,2Department of Public Health, Copenhagen University, DK-1014 Copenhagen, Denmark
| | - Anette Harris
- 3Department of Psychosocial Science, University of Bergen, N-5020 Bergen, Norway
| | - Øystein Vedaa
- 3Department of Psychosocial Science, University of Bergen, N-5020 Bergen, Norway
| | - Bjørn Bjorvatn
- 4Department of Global Public Health and Primary Care, University of Bergen, N-5018 Bergen, Norway
| | - Johnni Hansen
- 5Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark
| | - Åse Marie Hansen
- The National Research Center for the Working Environment, DK-2100 Copenhagen, Denmark.,2Department of Public Health, Copenhagen University, DK-1014 Copenhagen, Denmark
| | - Henrik A Kolstad
- 6Danish Ramazzini Centre, Department of Occupational Medicine, Aarhus University Hospital, DK-8200 Aarhus, Denmark
| | - Aki Koskinen
- Finnish Institute of Occupation Health, FI-00251 Helsinki, Finland
| | - Ståle Pallesen
- 3Department of Psychosocial Science, University of Bergen, N-5020 Bergen, Norway
| | - Annina Ropponen
- Finnish Institute of Occupation Health, FI-00251 Helsinki, Finland
| | - Mikko I Härmä
- Finnish Institute of Occupation Health, FI-00251 Helsinki, Finland
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Hammer PEC, Garde AH, Begtrup LM, Flachs EM, Hansen J, Hansen ÅM, Hougaard KS, Kolstad HA, Larsen AD, Pinborg AB, Specht IO, Bonde JP. Night work and sick leave during pregnancy: a national register-based within-worker cohort study. Occup Environ Med 2019; 76:163-168. [DOI: 10.1136/oemed-2018-105331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/05/2018] [Accepted: 12/19/2018] [Indexed: 11/03/2022]
Abstract
ObjectiveThe aim of our study was to investigate the acute effect of night work during pregnancy on the risk of calling in sick the following day using register-based information and the workers as their own controls.MethodsUsing the payroll-based national Danish Working Hour Database, including all public hospital employees in Denmark, we identified 9799 pregnant women with ≥1 day shift and ≥1 night shift and ≥1 day of sick leave during the first 32 pregnancy weeks from January 2007 to December 2013. We performed fixed effects logistic regression, that is, within-worker comparisons, of the risk of sick leave of any duration starting within 24 hours after night shifts of different length versus day shifts.ResultsMost of the participants were nurses (64%) or physicians (16%). We found an increased relative risk of sick leave following night shifts compared with day shifts during all pregnancy trimesters. The risk was highest for night shifts lasting >12 hours (OR 1.37, 95% CI 1.15 to 1.63 for nurses; OR 1.87, 95% CI 1.69 to 2.08 for physicians) and among women aged >35 years (OR 1.42, 95% CI 1.24 to 1.63).ConclusionAmong Danish public hospital employees night shifts during pregnancy, especially shifts longer than 12 hours, increased the risk of calling in sick the following day independent of personal factors and time-invariant confounders in all pregnancy trimesters.
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Li J, Bidlingmaier M, Petru R, Pedrosa Gil F, Loerbroks A, Angerer P. Impact of shift work on the diurnal cortisol rhythm: a one-year longitudinal study in junior physicians. J Occup Med Toxicol 2018; 13:23. [PMID: 30123312 PMCID: PMC6090626 DOI: 10.1186/s12995-018-0204-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/11/2018] [Indexed: 01/03/2023] Open
Abstract
Background Cumulative epidemiological evidence suggests that shift work exerts harmful effects on human health. However, the physiological mechanisms are not well understood. This study aimed to examine the impact of shift work on the dysregulation of the hypothalamic-pituitary-adrenal axis, i.e. diurnal cortisol rhythm. Methods Seventy physicians with a mean age 30 years participated in this one-year longitudinal study. Working schedules, either shift work or regular schedules with day shift, were assessed at baseline. Salivary cortisol samples were collected on two consecutive regular working days, four times a day (including waking, + 4 h, + 8 h, and + 16 h), at both baseline and the one-year follow-up. The diurnal cortisol decline (slope) and total cortisol concentration (area under the curve, AUC) were calculated. Results After adjusting for cortisol secretion at baseline and numerous covariates, shift work at baseline significantly predicted a steeper slope (p < 0.01) and a larger AUC (p < 0.05) of diurnal cortisol rhythm at follow-up in this sample of physicians. In particular, waking cortisol at follow-up was significantly higher among those engaged in shift work than day shift (p < 0.01). Conclusions Our findings support the notion that shift work changes the diurnal cortisol pattern, and is predictive of increased cortisol secretion consequently in junior physicians.
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Affiliation(s)
- Jian Li
- 1Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Faculty of Medicine, University of Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Martin Bidlingmaier
- 2Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Ludwig-Maximilians-University, Munich, Germany
| | - Raluca Petru
- 3Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, WHO Collaborating Centre for Occupational Health, Ludwig-Maximilians-University, Munich, Germany
| | - Francisco Pedrosa Gil
- Clinic for Psychiatry, Psychotherapy and Psychosomatics, Helios Vogtland Clinical Center, Plauen, Germany
| | - Adrian Loerbroks
- 1Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Faculty of Medicine, University of Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Peter Angerer
- 1Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Faculty of Medicine, University of Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
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Deng N, Haney NM, Kohn TP, Pastuszak AW, Lipshultz LI. The Effect of Shift Work on Urogenital Disease: a Systematic Review. Curr Urol Rep 2018; 19:57. [PMID: 29808235 DOI: 10.1007/s11934-018-0815-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE OF REVIEW Non-standard shift work schedules negatively impact the overall health of shift workers, and several studies have shown that shift work, specifically, is detrimental to urogenital health. The aims of this study are to systematically review the literature and determine the effect of shift work on the outcomes of hypogonadism, male infertility, lower urinary tract symptoms, and urogenital cancers. RECENT FINDINGS Recent evidence supports associations between non-standard shift work and an increase in the frequency of prostate cancer and the severity of erectile dysfunction, lower urinary tract symptoms, and hypogonadal symptoms, as well as worsening of semen parameters and fertility. These associations are strengthened by the presence of shift work sleep disorder (SWSD) which affects up to 20% of shift workers. No studies have assessed the impact of shift work on the frequency or severity of nephrolithiasis, interstitial cystitis, pelvic pain, prostatitis, or urinary tract infections. Non-standard shift work has been associated with a variety of negative health outcomes and urologic complications, especially with concurrent shift work sleep disorder. Recognition of these elevated risks among shift workers can aid in more effective screening for urologic conditions.
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Affiliation(s)
- Nanfu Deng
- Baylor College of Medicine, Houston, TX, USA
| | - Nora M Haney
- Tulane University School of Medicine, New Orleans, LA, USA
| | | | - Alexander W Pastuszak
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA
- Scott Department of Urology, Baylor College of Medicine, 6624 Fannin Street Suite 1700, Houston, TX, 77030, USA
| | - Larry I Lipshultz
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA.
- Scott Department of Urology, Baylor College of Medicine, 6624 Fannin Street Suite 1700, Houston, TX, 77030, USA.
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Abstract
PURPOSE OF REVIEW Night work is increasingly common and a necessity in certain sectors of the modern 24-h society. The embedded exposure to light-at-night, which suppresses the nocturnal hormone melatonin with oncostatic properties and circadian disruption, i.e., misalignment between internal and external night and between cells and organs, are suggested as main mechanisms involved in carcinogenesis. In 2007, the International Agency for Research on Cancer (IARC) classified shift work that involves circadian disruption as probably carcinogenic to humans based on limited evidence from eight epidemiologic studies on breast cancer, in addition to sufficient evidence from animal experiments. The aim of this review is a critical update of the IARC evaluation, including subsequent and the most recent epidemiologic evidence on breast cancer risk after night work. RECENT FINDINGS After 2007, in total nine new case-control studies, one case-cohort study, and eight cohort studies are published, which triples the number of studies. Further, two previous cohorts have been updated with extended follow-up. The assessment of night shift work is different in all of the 26 existing studies. There is some evidence that high number of consecutive night shifts has impact on the extent of circadian disruption, and thereby increased breast cancer risk, but this information is missing in almost all cohort studies. This in combination with short-term follow-up of aging cohorts may explain why some cohort studies may have null findings. The more recent case-control studies have contributed interesting results concerning breast cancer subtypes in relation to both menopausal status and different hormonal subtypes. The large differences in definitions of both exposure and outcome may contribute to the observed heterogeneity of results from studies of night work and breast cancer, which overall points in the direction of an increased breast cancer risk, in particular after over 20 years of night shifts. Overall, there is a tendency of increased risk of breast cancer either after over 20 years of night shift or after shorter periods with many consecutive shifts. More epidemiologic research using standardized definitions of night work metrics and breast cancer subtypes as well as other cancers is needed in order to improve the epidemiologic evidence in combination with animal models of night work. Also, evidence-based preventive interventions are needed.
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Affiliation(s)
- Johnni Hansen
- Danish Cancer Society Research Center, Strandboulevarden 49, 2100, Copenhagen, Denmark.
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Daugaard S, Garde AH, Bonde JPE, Christoffersen J, Hansen ÄM, Markvart J, Schlünssen V, Skene DJ, Vistisen HT, Kolstad HA. Night work, light exposure and melatonin on work days and days off. Chronobiol Int 2017; 34:942-955. [DOI: 10.1080/07420528.2017.1327867] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Stine Daugaard
- Aarhus University Hospital, Department of Occupational Medicine, Aarhus, Denmark
| | - Anne Helene Garde
- National Research Centre for the Working Environment, Copenhagen, Denmark
- University of Copenhagen, Institute of Public Health, Copenhagen, Denmark
| | - Jens Peter Ellekilde Bonde
- Bispebjerg Hospital, Department of Occupational Medicine, Copenhagen, Denmark
- University of Copenhagen, Institute of Public Health, Copenhagen, Denmark
| | - Jens Christoffersen
- Velux Danmark A/S, Stakeholder Communications and Sustanability, Horsholm, Denmark
| | - Äse Marie Hansen
- National Research Centre for the Working Environment, Copenhagen, Denmark
- University of Copenhagen, Institute of Public Health, Copenhagen, Denmark
| | - Jakob Markvart
- Aalborg Universitet, Department of Energy Performance, Indoor Environment and Sustainability, Danish Building Research Institute, Copenhagen, Denmark
| | - Vivi Schlünssen
- National Research Centre for the Working Environment, Copenhagen, Denmark
- Aarhus Universitet, Department of Public Health, Aarhus, Denmark
| | - Debra J. Skene
- University of Surrey, Faculty of Health and Medical Sciences, Chronobiology, Guildford GU2 7XH, Surrey, United Kingdom
| | - Helene Tilma Vistisen
- Aarhus University Hospital, Department of Occupational Medicine, Aarhus, Denmark
- Aarhus University Hospital, Aarhus, Denmark
| | - Henrik A. Kolstad
- Aarhus University Hospital, Department of Occupational Medicine, Aarhus, Denmark
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The Impact of Shiftwork on Skeletal Muscle Health. Nutrients 2017; 9:nu9030248. [PMID: 28282858 PMCID: PMC5372911 DOI: 10.3390/nu9030248] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/26/2017] [Accepted: 03/03/2017] [Indexed: 01/11/2023] Open
Abstract
(1) Background: About one in four workers undertake shift rosters that fall outside the traditional 7 a.m.-6 p.m. scheduling. Shiftwork alters workers' exposure to natural and artificial light, sleep patterns, and feeding patterns. When compared to the rest of the working population, shiftworkers are at a greater risk of developing metabolic impairments over time. One fundamental component of metabolic health is skeletal muscle, the largest organ in the body. However, cause-and-effect relationships between shiftwork and skeletal muscle health have not been established; (2) Methods: A critical review of the literature was completed using online databases and reference lists; (3) Results: We propose a conceptual model drawing relationships between typical shiftwork consequences; altered light exposure, sleep patterns, and food and beverage consumption, and drivers of skeletal muscle health-protein intake, resistance training, and hormone release. At present, there is no study investigating the direct effect of shiftwork on skeletal muscle health. Instead, research findings showing that acute consequences of shiftwork negatively influence skeletal muscle homeostasis support the validity of our model; (4) Conclusion: Further research is required to test the potential relationships identified in our review, particularly in shiftwork populations. Part of this testing could include skeletal muscle specific interventions such as targeted protein intake and/or resistance-training.
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