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

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

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Relationship of work-related stress with obesity among Brazilian female shift workers

Public Health Nutrition ◽

10.1017/s1368980020004243 ◽

2020 ◽

pp. 1-7

Author(s):

Janaína Cristina da Silva ◽

Anderson Garcez ◽

Gabriela Herrmann Cibeira ◽

Heloísa Theodoro ◽

Maria Teresa Anselmo Olinto

Keyword(s):

Shift Work ◽

Night Shift ◽

Cross Sectional Study ◽

Cross Sectional ◽

Work Related Stress ◽

Shift Workers ◽

Night Shift Work ◽

Work Related ◽

Prevalence Of Obesity ◽

Related Stress

Abstract Objectives: To explore the relationship between work-related stress and obesity among female shift workers. Additionally, we also aimed to test the interaction between shift work and work-related stress in this association. Design: A cross-sectional study was conducted among Brazilian female shift workers. Work-related stress was assessed through a demand–control questionnaire (Job Stress Scale). Work-related stress was defined by the presence of high psychological demands and low control at work. The obesity cases were defined as those with a BMI of 30 kg/m2 or more. Multivariate Poisson regression with robust variance was used to obtain the prevalence ratios (PR) and their respective 95 % CI. Setting: A group of industries located in southern Brazil in 2017. Participants: Four hundred and twenty female workers aged 18–59 years. Results: The overall prevalence of obesity was 30 % (95 % CI: 25·6, 34·4), and the presence of work-related stress was identified in 24 % (95 % CI: 19·9, 28·1) of the sample. We found an indication of interaction between work-related stress and night shift work on obesity (P = 0·026). After adjusting for confounding factors, work-related stress was associated with a 71 % greater probability of obesity (PR = 1·71; 95 % CI: 1·02, 2·87; P = 0·042) among female night shift workers. Conclusions: In this study, we revealed that exposure to work-related stress and night shift work were associated with obesity among female shift workers. Furthermore, the prevalence of obesity was high among female shift workers.

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Relationship between Sleep and Hedonic Appetite in Shift Workers

Nutrients ◽

10.3390/nu12092835 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2835

Author(s):

Parisa Vidafar ◽

Sean W. Cain ◽

Ari Shechter

Keyword(s):

Weight Gain ◽

Food Intake ◽

Circadian Rhythms ◽

Sleep Quality ◽

Shift Work ◽

Poor Sleep ◽

Shift Workers ◽

Disturbed Sleep ◽

Food Intake Regulation ◽

Intake Regulation

Short and/or poor sleep are established behavioral factors which can contribute to excess food intake, and emerging evidence suggests that disturbed circadian rhythms may also impact food intake regulation. Together, disturbed sleep and circadian rhythms may help explain the excess risk for obesity seen in shift workers. To date, however, the details of how shift work may impact food intake regulation are still not fully defined. Here we examined the relationship between sleep characteristics and hedonic control of appetite in shift workers. A total of 63 shift workers (mean (M) age: 36.7 years, standard deviation (SD): 12.0; 59% women) completed an online survey comprising self-reported measures of body weight regulation, sleep (Pittsburgh Sleep Quality Index, Sleep Hygiene Index), and hedonic control of appetite (Food Craving Inventory, Power of Food Scale). Seventy-one percent reported some weight change since starting shift work, and 84% of those reported weight gain (M = +11.3 kg, SD = 9.1). Worse sleep quality and shorter sleep duration were associated with more food cravings, and worse sleep quality and hygiene were associated with higher appetitive drive to consume palatable food (greater hedonic drive). This preliminary study suggests hedonic pathways are potentially contributing to weight gain in shift workers with disturbed sleep.

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

Circulation ◽

10.1161/circ.142.suppl_3.14384 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Juliane Hannemann ◽

Anika Laing ◽

Benita Middleton ◽

Jonathan Cridland ◽

Bart Staels ◽

...

Keyword(s):

Blood Pressure ◽

Circadian Rhythms ◽

Glucose Tolerance ◽

Shift Work ◽

Therapy Group ◽

Night Shift ◽

Light Therapy ◽

Pressure Control ◽

Shift Workers ◽

Night Shifts

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

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Circadian principles and design of rotating shift work schedules

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1986.251.3.r636 ◽

1986 ◽

Vol 251 (3) ◽

pp. R636-R638 ◽

Cited By ~ 1

Author(s):

F. W. Turek

Keyword(s):

Circadian Rhythms ◽

Shift Work ◽

Sleep Time ◽

New Work ◽

Work Schedules ◽

Work Schedule ◽

Work Time ◽

Shift Workers ◽

Rotating Shift Work ◽

Night Shifts

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

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Psycho-Social Impact of Shift Work

Business, Technology, and Knowledge Management in Asia ◽

10.4018/978-1-4666-2652-2.ch013 ◽

2013 ◽

pp. 166-174

Author(s):

Rupashree Goswami ◽

R. K. Jena ◽

B. B. Mahapatro

Keyword(s):

Job Satisfaction ◽

Shift Work ◽

Systematic review of shift work and nurses’ health

Occupational Medicine ◽

10.1093/occmed/kqz063 ◽

2019 ◽

Vol 69 (4) ◽

pp. 237-243 ◽

Cited By ~ 9

Author(s):

D Rosa ◽

S Terzoni ◽

F Dellafiore ◽

A Destrebecq

Keyword(s):

Circadian Rhythms ◽

Shift Work ◽

Family Relationships ◽

Healthcare Providers ◽

Work Schedule Tolerance ◽

Work Related ◽

Randomized Controlled ◽

Search Terms ◽

Related Stress ◽

Metabolic Cardiovascular Syndrome

Abstract Background Nursing is characterized by a working articulation in shifts to ensure continuity of care throughout the 24 h. However, shift work and the resulting desynchronization of circadian rhythms may have adverse effects on nurses’ health. Aims To describe the effects of shift work and desynchronization of circadian rhythms on nurse’s health. Methods Databases: PubMed, Cinahl, Scopus, Embase and Ilisi. Search terms (free terms, MeSH): ‘nurses’, ‘shiftwork’, ‘nightwork’, ‘sleep disorder, circadian rhythm’, ‘work schedule tolerance’, ‘breast neoplasm’, ‘metabolic syndrome X’, ‘metabolic cardiovascular syndrome’, ‘Cardiovascular disease’, ‘stress’, ‘diabetes’. We included all randomized controlled trials, observational studies, reviews and papers studying nurses’ shift work. Quality assessment of the retrieved papers was verified according to Dixon-Woods checklist. Results Twenty-four articles were analyzed. Literature review has shown that shift work involves an alteration in psychophysical homeostasis, with a decrease in performance. It is an obstacle for social and family relationships, as well as a risk factor for stress, sleep disorders, metabolic disorders, diabetes, cardiovascular disorders and breast cancer. Conclusions An organized ergonomic turnaround can be less detrimental to the health of nurses and more beneficial for the healthcare providers. Therefore, we suggest organizing studies to assess whether improving nurses’ health would lead to a reduction in miscarriages, absenteeism and work-related stress.

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The Effects of Shift Work on Cardio-Metabolic Diseases and Eating Patterns

Nutrients ◽

10.3390/nu13114178 ◽

2021 ◽

Vol 13 (11) ◽

pp. 4178

Author(s):

Alexandra Hemmer ◽

Julie Mareschal ◽

Charna Dibner ◽

Jacques A. Pralong ◽

Victor Dorribo ◽

...

Keyword(s):

Circadian Rhythms ◽

Health Outcomes ◽

Shift Work ◽

Metabolic Disorders ◽

Metabolic Diseases ◽

Eating Patterns ◽

Shift Workers ◽

Circadian Misalignment ◽

The Metabolic Syndrome ◽

Physiological Markers

Energy metabolism is tightly linked with circadian rhythms, exposure to ambient light, sleep/wake, fasting/eating, and rest/activity cycles. External factors, such as shift work, lead to a disruption of these rhythms, often called circadian misalignment. Circadian misalignment has an impact on some physiological markers. However, these proxy measurements do not immediately translate into major clinical health outcomes, as shown by later detrimental health effects of shift work and cardio-metabolic disorders. This review focuses on the effects of shift work on circadian rhythms and its implications in cardio-metabolic disorders and eating patterns. Shift work appears to be a risk factor of overweight, obesity, type 2 diabetes, elevated blood pressure, and the metabolic syndrome. However, past studies showed discordant findings regarding the changes of lipid profile and eating patterns. Most studies were either small and short lab studies, or bigger and longer cohort studies, which could not measure health outcomes in a detailed manner. These two designs explain the heterogeneity of shift schedules, occupations, sample size, and methods across studies. Given the burden of non-communicable diseases and the growing concerns about shift workers’ health, novel approaches to study shift work in real contexts are needed and would allow a better understanding of the interlocked risk factors and potential mechanisms involved in the onset of metabolic disorders.

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Psycho-Social Impact of Shift Work

International Journal of Asian Business and Information Management ◽

10.4018/jabim.2011100103 ◽

2011 ◽

Vol 2 (4) ◽

pp. 20-28

Author(s):

Rupashree Goswami ◽

R. K. Jena ◽

B. B. Mahapatro

Keyword(s):

Shift Work ◽

Adverse effects of circadian desynchrony on the male reproductive system: an epidemiological and experimental study

Human Reproduction ◽

10.1093/humrep/deaa101 ◽

2020 ◽

Vol 35 (7) ◽

pp. 1515-1528 ◽

Cited By ~ 2

Author(s):

Kun Liu ◽

Guizhong Hou ◽

Xiaogang Wang ◽

Huatao Chen ◽

Fuquan Shi ◽

...

Keyword(s):

Reproductive Health ◽

Mouse Model ◽

Shift Work ◽

Sperm Count ◽

Reproductive Hormones ◽

Semen Parameters ◽

Shift Workers ◽

Chinese Men ◽

Work Related ◽

Male Reproductive Health

Abstract STUDY QUESTION Is circadian desynchrony a risk factor of male reproductive damage in semen parameters and/or reproductive hormones? SUMMARY ANSWER Circadian desynchrony correlates with decrease of sperm count, which was improved when circadian desynchrony was attenuated. WHAT IS KNOWN ALREADY Circadian desynchrony caused by work (shift work) and non-work-related reasons is prevalent worldwide and has been found to be associated with decreased female fertility, but whether it harms male reproductive health is unclear. STUDY DESIGN, SIZE, DURATION A hybrid research was conducted. (i) A cross-sectional study of 1346 Chinese men in 2007 was used to analyze the association between semen/hormone biomarkers and work-related circadian desynchrony, which was divided into rotating shift work and permanent shift work against non-shift work. (ii) A cohort of 796 Chinese undergraduates from 2013 to 2014 was used to analyzed the association between semen/hormone biomarkers and non-work-related circadian desynchrony (between school days and days off). (iii) The biomarker identified simultaneously in both populations was further validated in male C57BL/6J mice housed under conditions simulating circadian desynchrony. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 17 semen/hormone biomarkers were compared among rotating shift workers and permanent shift workers against non-shift workers in the 1346 reproductive-age Chinese men. A total of 14 semen/hormone biomarker was analyzed in the undergraduate cohort for correlation with non-work-related circadian desynchrony (measured by Munich Chronotype Questionnaire) in 2013 and 2014 and compared between the 2 years. Photoperiod-shifting method was used to establish the mouse model, in which the biomarker was examined and molecular mechanism was explored by apoptosis analysis, DNA content analysis, transcriptome sequencing, real-time PCR and western blotting. MAIN RESULTS AND THE ROLE OF CHANCE Among the semen/hormone biomarkers, sperm count was found to be lower in rotating shift workers, who had a higher risk of low sperm count defined by Chinese Ministry of Health (total sperm/ejaculate < 120 × 106) than non-shift workers (odds ratio = 1.26, 95% CI 1.05–1.52). This biomarker was replicated in the undergraduate cohort, where each hour of circadian desynchrony was associated with 1.16 (95% CI 1.02–1.31) fold odds of low sperm count, and sperm count increased during 2014 in men who reduced circadian desynchrony after 2013. A decrease of sperm count with circadian desynchrony and its recovery after removal of circadian desynchrony was also observed in the mouse model. During asynchrony, increased apoptosis was found in seminiferous tubules and the marker genes of post-spermatocyte stage cells were down-regulated. The most enriched functional pathway was homologous recombination, which happened during meiosis. LIMITATIONS, REASONS FOR CAUTION The study of human beings was observational while the animal study has potential difference in circadian desynchrony exposure and species susceptibility. Further researches are needed to clarify the causal relationship in men. WIDER IMPLICATIONS OF THE FINDINGS These findings provide novel insight to the effect of circadian desynchrony on male reproductive health and a potential strategy for prevention of reproductive damage. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the National Key R&D Program of China [2017YFC1002001] and National Natural Science Foundation of China [81871208]. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER NA.

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An Exploration of Shift Work, Fatigue, and Gender Among Police Officers: The BCOPS Study

Workplace Health & Safety ◽

10.1177/2165079918754586 ◽

2018 ◽

Vol 66 (11) ◽

pp. 530-537 ◽

Cited By ~ 3

Author(s):

John M. Violanti ◽

Sherry L. Owens ◽

Desta Fekedulegn ◽

Claudia C. Ma ◽

Luenda E. Charles ◽

...

Keyword(s):

Shift Work ◽

Police Officers ◽

Poisson Regression ◽

Prevalence Ratio ◽

Lower Prevalence ◽

Work History ◽

Shift Workers ◽

Item Questionnaire ◽

And Gender ◽

History Database

The present study examined the association between shift work and fatigue among male ( n = 230) and female ( n = 78) police officers. A 15-year work history database was used to define dominant shifts as day, afternoon, or night. A 10-item questionnaire created from the Standard Shiftwork Index (SSI) assessed fatigue. Gender-stratified analyses of variance and covariance and Poisson regression were used to compare means and prevalence of individual items across shifts. No significant differences in total fatigue scores were observed across shifts. However, the prevalence of the fatigue item “feelings of tiredness” was 89% higher among male officers working the afternoon shift compared with officers working the day shift (prevalence ratio [PR] = 1.89, 95% confidence interval [CI] = [1.12, 3.23], p = .020), after adjustment for covariates. Women reported a lower prevalence of tiredness than men on the afternoon shift. Organizations with afternoon shift workers should consider reducing fatigue at work through education and other methods.

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