Group Of Shift Workers Research Articles

Circadian rhythm sleep loss impairs motor inhibition more than motor execution in continuous action

Under total sleep deprivation, both inhibitory and motor control are impaired. However, how circadian rhythm sleep loss caused by irregular sleep pattern affects motor inhibition and execution in continuous actions remains unknown. This study utilized a pointing task to investigate the question over 30 days. During regular trials, participants were instructed to tap on a specified location, while in countermanding trials, they were required to countermand their current action. Additionally, there was a control group performed the same task following a normal 24-h rhythm. The results indicated that the decrease in accuracy and the increase in movement time in countermanding trials were more prominent in the shift work group. In contrast, there was no significant difference in reaction time between the two groups. Notably, the shift work group outperformed the control group in terms of movement time in regular trials and radial displacement in countermanding trials. Overall, these results show that circadian rhythm sleep loss predominantly affects inhibitory control, rather than motor control, underscoring the nuanced impacts of sleep disruption on differential aspects of cognitive and motor functions.

The influence of night shift work and associated factors on serum uric acid in aircraft maintenance workers

Background and objectiveThe prevalence of 12-hour shift work is increasing in various occupations. Shift work has been linked to circadian rhythm disruption, which may lead to hormonal changes and metabolic disorders, including alterations in glucose, lipid, and purine metabolism. Despite this, there is limited research on the potential connection between work shifts and abnormal serum uric acid (SUA) levels. Furthermore, the factors that contribute to abnormal SUA levels in shift workers are not well-understood. Therefore, this study aimed to analyze the SUA levels of shift workers employed in an aircraft maintenance company, investigate the potential association between shift work and SUA levels, and explore the factors that may influence abnormal SUA levels in shift workers.MethodsA total of 2263 male workers from an aircraft maintenance company were included in this study using the cluster sampling method. The workers were divided into two groups based on their working shifts: night shift (N = 1047, 46.27%) and day working (N = 1216, 53.73%). A survey was conducted between April 1st and June 30th, 2022 to gather information on work, lifestyle, physical examination results, and other relevant factors. The survey included a self-designed demographic information questionnaire to collect data on workers’ characteristics, medical history, years of employment, smoking and drinking habits, and main lifestyle behaviors. The workers’ SUA levels were measured using uricase colorimetry. One-way ANOVA was used to compare the difference in the abnormal detection rate of SUA between the two groups, and multi-factor logistic regression analysis was used to identify the factors that influence abnormal SUA levels.ResultsThe study indicated that 48.9% of night shift workers and 43.8% in the regular day workers had abnormal SUA levels, with a significant difference between the two groups (χ2 = 6.125, P = 0.013). Factors such as circadian rhythm type, shift work, age, the taste of diet, type of diet, smoking, overweight or obesity based on body mass index (BMI), concentration of urine creatinine (CREA), total cholesterol, triglyceride, and low-density lipoprotein cholesterol were found to be correlated with SUA abnormalities (P < 0.05). The risk of developing SUA abnormalities was found to be higher in individuals with an intermittent (OR = 1.34, 95% CI: 0.83–2.12, P < 0.05) or evening circadian rhythm type (OR = 1.45, 95% CI: 0.86–2.43, P > 0.05) compared to those with a morning type. Additionally, factors such as night shift work, a high-sodium diet, smoking, a diet high in meat and low in vegetables, being overweight or obese, and higher levels of CREA were also found to increase the risk of developing SUA abnormalities. The study also revealed a significant dose-response relationship between BMI and abnormal uric acid levels. After controlling for other factors, the risk of developing SUA abnormalities was found to be 1.18 times higher in the night shift work group than in the day work group (OR = 1.18, 95% CI:1.02–1.34, P = 0.01).ConclusionShift work has been linked to a higher risk of developing SUA abnormalities, and there are several factors that may contribute to this risk. To prevent diseases, it is recommended that enterprises implement better health monitoring and management practices for shift workers.

Investigation of the possible effects of night shift on telomere length and mtDNA copy number in nurses

In this study, we aimed to investigate the impacts of altered circadian rhythm on telomere length and mtDNA copy number (mtDNA-CN) in nurses working night shifts. In our study, 52 healthy nurses working in shifts at Ondokuz Mayıs University Hospital and 45 healthy control subjects working during the day were included. qRT-PCR technique was used for the determination of telomere length and mtDNA-CN. It was observed that the shift-work group had poor sleep quality (p = 0.004), feeling tired (p < 0.01) and stressed (p = 0.02) more than control group working during the day. Nurses working in shifts were found to have 1.18 times longer telomeres with respect to the control group working during the day (p = 0.005). When compared among shift workers, poor sleep quality and insufficient sleep duration shortened telomeres (r = 0.32; p = 0.02). There was no statistically significantdisparity regarding mtDNA-CN among the nurses working in shifts and the control group working during the day (p = 0.07). Insufficient sleep was associated with decreased mtDNA-CN when shift-working nurses were compared according to sleep quality (p = 0.006). Furthermore, mtDNA-CN of nurses with poor sleep quality was correlated with lower mtDNA-CN in comparison to nurses with good sleep quality (r = 0.284; p = 0.04). The mtDNA-CN of the nurses was positively associated with the sleep duration the night sleep before the night shift (r = 0.32; p = 0.02). Inadequate sleep duration and quality were observed to cause a reduction in mtDNA-CN of nurses. In conclusion, it has been observed that poor sleep quality and duration are related to shortened telomere length and decreased mtDNA-CN in night shift nurses.

Sleep factors were associated with a higher risk of MAFLD and significant fibrosis.

The relationships of sleep factors separately and jointly with metabolic associated fatty liver disease (MAFLD) and significant fibrosis remain unclear. We intended to explore the relationships in the United States. This cross-sectional study included 4477 individuals from the National Health and Nutrition Examination Survey from 2017 to 2018. Information regarding each sleep factor (sleep duration, trouble sleeping, snoring, excessive daytime sleep, and sleep apnea symptoms) was obtained through questionnaires. MAFLD was diagnosed by transient elastography according to the consensus definitions. Multivariable logistic regression models were employed to explore relationships of sleep factors separately and jointly with MAFLD and significant fibrosis. Participants having a poor sleep pattern was associated with higher MAFLD and significant fibrosis risk, and poor sleep pattern was related to about threefold (OR, 3.67; 95% CI, 1.82-7.37) increased risk of MAFLD remarkably. When examining specific factors of sleep patterns individually, trouble sleeping (OR, 1.53; 95% CI, 1.10-2.12), snoring (OR, 2.11; 95% CI, 1.40-3.19), excessive daytime sleep (OR, 1.57; 95% CI, 0.93-2.62), and sleep apnea symptoms (OR, 1.87; 95% CI, 1.13-3.10) were positively associated with the odds of MAFLD (all P < 0.05). However, sleep duration was not independently correlated with MAFLD or significant fibrosis. Sleep patterns showed similar relationships with MAFLD, regardless of all age, sex, physical activity, and shift work groups. Poor sleep pattern was linked with a considerably higher risk of MAFLD and significant fibrosis.

Dietary Patterns under the Influence of Rotational Shift Work Schedules: A Systematic Review and Meta-Analysis.

Workers employed in rotating shift schedules are at a higher metabolic risk compared with those in regular day and fixed shift schedules; however, the contribution of diet is unclear. This systematic review aimed to investigate how rotating shift work schedules affect dietary energy intake and dietary patterns compared with regular day and fixed shift schedules. In addition, intraperson energy intake and dietary pattern comparisons within rotating shift schedules were investigated. Database searches were conducted on MEDLINE, Cochrane, CINAHL, PSYCinfo, EMBASE, and Scopus, in addition to manual search of bibliographic references, to identify articles. Two separate meta-analyses compared dietary intake between day work and rotating shift work schedules and within the rotational shift work group (morning/day and night shifts). Differences in dietary patterns were synthesized narratively. Thirty-one studies (n = 18,196 participants) were included in the review, and meta-analyses were conducted with 24-hour mean energy intake data from 18 (n = 16,633 participants) and 7 (n = 327 participants) studies, respectively. The average 24-hour energy intake of rotating shift workers was significantly higher than that of workers in regular daytime schedules [weighted mean difference (WMD): 264 kJ; 95% confidence interval (CI): 70, 458 kJ; P < 0.008; I2 = 63%]. However, the mean difference in 24-hour energy intake between morning/day shifts compared with night shifts within rotational shift schedules was not statistically significant (WMD: 101 kJ; 95% CI: -651, 852 kJ; P = 0.79; I2 = 77%). Dietary patterns of rotating shift workers were different from those of day workers, showing irregular and more frequent meals, increased snacking/eating at night, consumption of fewer core foods, and more discretionary foods. This review highlights that dietary intake in rotational shift workers is potentially higher in calories and features different eating patterns as a consequence of rotating shift work schedules. This review was registered at PROSPERO as ID 182507.

The Prolonged Effect of Shift Work and the Impact of Reducing the Number of Nightshifts on Arterial Stiffness-A 4-Year Follow-Up Study.

To assess changes in blood pressure (BP) and arterial stiffness among 84 rotating shift and 25 dayworkers (control subjects) at two industrial plants during a 4-year follow-up, and to assess changes in outcome variables among shift workers at the two plants after a reduction in the number of night shifts during the last year of follow-up in one of the plants. We collected demographic data using a questionnaire, examined systolic and diastolic blood pressure (sBP, dBP), central systolic and diastolic aorta pressure (cSP, cDP), augmentation pressure (AP), central pulse pressure (cPP), and pulse wave velocity (PWV). We registered sleep quality. The last 4-14 months of follow-up one plant implemented a 12-week shift plan reducing the total number of night shifts and consecutive night shifts from 16.8 to 14 and from 7.2 to 4. To assess differences in change of outcomes between study groups we applied linear mixed models. The dayworkers were older, more hypertensive, reported less sleep disturbance, and smoked/snuffed less than the shift workers did. The adjusted annual increase in PWV was 0.34 m/s (95%CI, 0.22, 0.46) among shift workers and 0.09 m/s (95%CI, -0.05, 0.23) in dayworkers, yielding a significant difference of change of 0.25 m/s (95%CI, 0.06, 0.43). No significant differences were found between the two groups of shift workers in any cardiovascular disease (CVD) outcome during the last year of follow-up. Shift work in industry is associated with arterial stiffness, reflecting an increased risk of future CVD. No significant changes in arterial stiffness were identified as a consequence of a small reduction in the number of night shifts and consecutive night shifts.

Effect of night shift work on the reduction of glomerular filtration rate using data from Korea Medical Institute (2016-2020).

Shift work increases the risk of chronic diseases, including metabolic diseases. However, studies on the relationship between shift work and renal function are limited. The aim of this study was to investigate the association between shift work and a decreased glomerular filtration rate (GFR). Data were evaluated for 1,324,930 workers who visited the Korean Medical Institute from January 1, 2016 to December 31, 2020 and underwent a health checkup. Daytime workers were randomly extracted at a ratio of 1:4 after matching for age and sex. In total, 18,190 workers aged over 40 years were included in the analyses; these included 3,638 shift workers and 14,552 daytime workers. Participants were categorized into the shift work group when they underwent a specific health checkup for night shift work or indicated that they were shift workers in the questionnaire. The odds ratio was calculated using a conditional logistic regression to investigate the relevance of shift work for changes in GFR. 35 workers in the shift group and 54 in the daytime group exhibited an estimated GFR (eGFR) value of < 60 mL/min/1.73m2 (p < 0.01). The difference in eGFR values between two checkups differed significantly depending on the type of work (p < 0.01); the difference in the shift work group (-9.64 mL/min/1.73 m2) was larger than that in the daytime work group (-7.45 mL/min/1.73 m2). The odds ratio for eGFR reduction to < 60 mL/min/1.73 m2 in the shift group versus the daytime group was 4.07 (95% confidence interval: 2.54-6.52), which was statistically significant. The results of this study suggest that eGFR decreases by a significantly larger value in shift workers than in daytime workers; thus, shift work could be a contributing factor for chronic kidney disease (CKD). Further prospective studies are necessary to validate this finding and identify measures to prevent CKD in shift workers.

Shift work and nonalcoholic fatty liver disease incidence among Chinese rail workers: a 4-year longitudinal cohort study.

Occupational harmful factors, such as shift work, are attracting increasing attention as a potential cause of nonalcoholic fatty liver disease (NAFLD). In this study, we aimed to identify the association between shift work and NAFLD incidence in Chinese rail population. A cohort study was conducted among 14,112 rail workers for 4-year follow-up. Shift work frequency and other potential variables were recorded by questionnaires, including demographic, lifestyle, and occupation information. Besides, body mass index, blood pressure, fasting blood glucose, total cholesterol, triglyceride, alanine aminotransferase, and aspartate aminotransferase were measured by anthropometric measurement and blood test. Diagnosis of new NAFLD case was based on abdominal ultrasonography. Cox proportional hazards regression model was used to determine whether shift work has effect on occurrence of NAFLD. The incidence of NAFLD was 30.43% in total subjects. After adjustment for possible confounders, the RRs of NAFLD were 1.069 (95% CI 0.998-1.146) and 1.179 (95% CI 1.059-1.312) in occasionally shift work group and frequently shift work group respectively, compared to the seldom shift work group. In stratified analyses, the RRs of NAFLD incidence linked to shift work exposure seems increase among female and elder. The results of three sensitivity analyses were similar with main analysis. This research provided further evidence of positive harmful effect of shift work on NAFLD incidence in Chinese rail workers, particularly in frequently shift work population. The risk estimate of shift work on NAFLD was higher in female and elder.

The Impact of Rotating Night Shift Work and Daytime Recharge on Cognitive Performance Among Retired Nurses.

IntroductionThe exact relationship between long-term shift work (SW) and cognitive impairment (CI) has been poorly understood. The effects of the long-term rotating night SW (RNSW) combining daytime recharge (DTR) on cognitive function were investigated.MethodsA total 920 retired nurses and 656 retired female teachers aged ≥50 years were analyzed. Participants who worked at least once per week for 8 hat night for more than 1 year were defined as the SW group, and those without a regular nighttime shift were defined as the control group. The associations among duration, frequency, and DTR of RNSW, and neuropsychological assessments were ascertained by regression models.ResultsParticipants with RNSW had a significantly higher proportion of mild CI (MCI), both amnestic MCI (aMCI) (14.4% in 11–20 years, p < 0.05, and 17.8% in > 20 years, p < 0.001) and non-amnestic MCI (naMCI) (8.1% in 11–20 years, p < 0.05), as well as dementia (1.5% in 1–10 years, and 11.7% in > 20 years, p < 0.05) compared to controls (8.4% with aMCI, 4.4% with naMCI, and 7.0% with dementia, respectively). There were significant negative relationships between general times of night SW and scores of Mini-Mental State Examination (MMSE) (R squared = 0.01, p = 0.0014) and Montreal Cognitive Assessment (MoCA) (R squared = 0.01, p = 0.0054). Participants with ≥1 h of DTR and ≥ 11 years of RNSW were about 2-fold more likely to experience MCI compared with the subjects in the control group, especially with 3–5 h (odds ratio [OR]: 2.35; 95% confidence interval: 1.49–3.68, p < 0.001).ConclusionThe long-term RNSW was associated with a higher risk of CI, especially aMCI and dementia, and the problem cannot be improved by DTR.

Study of the physiological effects of shift work using the HRV analysis method

Shift work in industry and services cannot be avoided, but the adverse health effects of shift work are well known. The results of workplace physiological measurements in the Hungarian solid mineral mining oil and gas extraction and processing industry was, carried out under the coordination of the Scientific Committee on Mining Health and Ergonomics of the Hungarian Academy of Sciences, The Committee studiedy the variations of age and life characteristics of the workers, the various working conditions and environment and the heart rate variability (HRV) parameters. Our workplace studies covered 8, 12 and 24-hour shift works alike during morning, afternoon and night shifts with 2, 5 or 7 days per shift. In the evaluation, the significant differences in HRV parameters reflecting different physiological conditions, working conditions and work environment are presented for the morning only (control group) and the shift work groups. Evaluation of the results of the measurements carried out at the workplaces adjusted to the actual work schedule using known methods of mathematical statistics made it possible to investigate the effects of different circumstances and conditions. Based on the reviewed research results regarding the health effects of shift work, IARC/WHO concluded in 2010 that shift work was probably carcinogenic to humans (category 2A) - a recommendation that was changed to night shift work in 2019, based on the research results revealed in the meantime. Our studies call attention to the potential for using the results of new methods developed through innovation and to the justification for their use in occupational health.

Relationship between sleep disorders and hypertension in oil workers in Karamay City

To investigate the effect of sleep disorders on hypertension in oil workers and its mediating effect analysis. Between June and September 2019, 1420 workers aged 20-60 years(745 males and 675 females; 384 aged 30 years, 563 aged 30-45 years and 473 aged 45 years) from six oilfield bases in Karamay City, Xinjiang Uygur Autonomous Region were surveyed using a two-stage randomized whole-group sampling method. Their current conditions, and the information on gender, age, ethnicity, personal monthly income, education level, job title, smoking, alcohol consumption, height, weight, and shift work of the oil workers were investigated by the basic questionnaire. The Pittsburgh Sleep Index was used to assess the sleep status, and the Logistic regression model was used to analyze the influencing factors of hypertension, and the Process program(version 3.3) was used to conduct the mediating effect model test. (1) The detection rate of sleep disorders was 52.5% and the prevalence of hypertension was 16.3%, with 21.6%(161) higher in women than 10.5%(71) in men(χ~2=31.877, P& lt; 0.001). The prevalence of hypertension increased with increasing age and body mass index(BMI)(χ~2=25.117, P& lt; 0.001), 20.1%(149) in the sleep disorder group were higher than 12.2%(83) in the non-sleep disorder group(χ~2=16.113, P& lt; 0.001). (2) After adjusting for gender, age, ethnicity, education, personal monthly income, smoking, alcohol consumption, shift work and BMI, sleep disorders(OR=1.686, 95% CI 1.232-2.308), gender(OR=1.565, 95% CI 1.035-2.367), age(OR_(30-45)=1.710, 95% CI 1.085-2.697; OR_(& gt; 45)=1.717, 95% CI 1.055-2.797), shift work(OR=2.698, 95% CI 1.889-3.855), BMI(OR_(24.0-27.9)=2.557, 95% CI 1.736-3.765; OR_(≥28.0)=4.001, 95% CI 2.553-6.318) increased the risk of hypertension. (3) The result of stratified analysis showed that with age(OR_(30-45)=1.642, 95% CI 1.019-2.645; OR_(& gt; 45)=1.998, 95% CI 1.223-3.263) and BMI(OR_(24.0-27.9)=1.652, 95% CI 1.079-2.528; OR_(≥28.0)=2.259, 95% CI 1.165-4.381) increased, the risk of hypertension due to sleep disorders increased. Sleep disorders(OR=2.002, 95% CI 1.336-2.936) were also risk factors for hypertension in the shift work group. (4) The result of the mediating effect test showed that there was a mediating effect(P& lt; 0.05) between sleep disorders in age(β=0.240, Z=2.239), shift work(β=0.656, Z=3.999), and BMI(β=0.516, Z=7.258) and hypertension. Sleep disorders may be a risk factor affecting hypertension in oil workers in Karamay City, and there were mediating effects between age, shift work, and BMI and hypertension.

Association between metabolic syndrome and shift work in chemical plant workers.

BackgroundThe study aimed to determine the association between shift work and metabolic syndrome and the prevalence of metabolic syndrome in the shift and day work groups among workers working in chemical plants.MethodsBased on medical examination data collected in February 2019, 3,794 workers working at a chemical plant in Korea were selected. Multiple logistic regression analysis was performed by adjusting for age, sex, body mass index (BMI), drinking, exercise, smoking, employment period and organic compounds exposure.ResultsThe prevalence of metabolic syndrome in the entire study group was 23.4%, and the prevalence and components of metabolic syndrome in shift worker; waist circumference were higher than those of day workers (84.77 ± 8.64 vs. 83.41 ± 9.42, p < 0.001), systolic blood pressure (129.89 ± 9.47 vs. 127.57 ± 9.47, p < 0.001), diastolic blood pressure (81.22 ± 7.59 vs. 79.34 ± 7.46, p < 0.001), fasting blood glucose (99.27 ± 17.13 vs. 97.87 ± 13.07, p = 0.007), triglycerides (149.70 ± 101.15 vs. 133.55 ± 105.17, p < 0.001), and decreased high-density lipoprotein (53.18 ± 12.82 vs. 55.61 ± 14.17, p < 0.001). As a result of logistic regression analysis on the risk of metabolic syndrome, even after adjusting for age, sex BMI, drinking, smoking, exercise, employment period, organic compound exposure. the odds ratio (OR) for the shift group was 1.300 for daytime workers (Model 1, OR: 1.491; 95% confidence interval [CI]: 1.273–1.747; Model 2, OR: 1.260; 95% CI: 1.070–1.483; Model 3, OR: 1.309, 95% CI: 1.081–1.585; Model 4, OR: 1.300; 95% CI: 1.063–1.591).ConclusionsShift work in chemical plant workers increased the risk of metabolic syndrome, even after adjusting for general factors. To analyze the occupational cause and risk control, it is necessary to analyze the hazardous substances the workers were exposed to and their working environment. Additionally, a large-scale prospective analysis including general factors not analyzed in this study, such as eating habits, is required.

Effect of night shiftwork on lipid profile, hematological, and immunoinflammatory parameters in adult male wistar rats

Background: Adverse health outcomes of night shiftwork (NSW) have been reported from observational studies but interventional researches mimicking NSW are dearth. This study aimed to simulate NSW and investigate its effect on lipid profile, hematological, and immunoinflammatory parameters in adult male Wistar rats. Materials and Methods: Sixteen male Wistar rats aged between 8 and 10 weeks, weighing 100 g ± 12 g were equally and randomly divided into control and NSW groups. Night shift-work group was sleep restricted and exposed to light at night for 6 weeks. Lipids were analyzed using their respective Randox kits and chemistry Autoanalyser (mindry Ba-88a). Full blood count was done using an Automated Hematology analyzer (Mindray BC-10) and CD 4+ T-cells were estimated using an automated Partec Cyflow counter. Data were analyzed using SPSS V20.0 and summarized using mean ± standard error of means. Student's t-test was used to investigate differences between the groups and P ≤ 0.05 was considered as statistically significant. Results: The results demonstrated NSW rats to exhibit trends toward lower high-density lipoprotein, higher triglycerides, low-density lipoprotein, and lipid ratios compared to controls (P > 0.05). In addition, NSW group exhibited significant reduction in total WBC count, marginal decrease in CD4+ T-cells, and absolute lymphopenia. In addition, while erythrothrombotic parameters of the two groups appeared statistically similar, platelets-to-lymphocytes ratio is slightly higher and red cell distribution width coefficient is significantly lower in the NSW group. Conclusion: The present study has demonstrated the potentials of night shiftwork to increase atherogenic lipids, lower cardioprotective lipids, impair immunological competence and increase systemic inflammation in male Wistar rats. These finding have highlighted the need for extensive research effort in order to fully understand mechanisms through which NSW affect immunoinflammation, metabolic and cardiovascular health.

Shift Work: Impact on Nurses’ Health and Quality Life in Pointe-Noire (Congo)

Introduction: The consequences of shift work on health, psychological balance and socio-family life are multiple and universally known. Objective: The aim of this survey was to describe the impact of shift work on nurses’ health and quality life. Methodology: This was a cross-sectional descriptive study of the exposed and non-exposed type from May 2013 to July 2013, i.e. for a period of 3 months. We had included and divided into two groups the nurses working in the various departments of the Loandjili General Hospital (LGH). A questionnaire derived from the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale had been used to collect the data. Results: Of the 91 nurses considered, including 59 in shift work (group I) and 32 in daytime work (group II), significant associations were found between shift work on the one hand and sleep problems on the other hand in all these aspects, stress and appetite disturbances. However, no significant association was found between shift work on the one hand and the use of sleeping pills on the other hand. Fatigue, mood disorders and the notion of free time (at home and for leisure), although the frequencies are relatively high in the group of nurses on shift work. Conclusion: Our results show that nurses’ health, social and family life at Loandjili General Hospital are negatively impacted by shift work. There is a need to put in place means of prevention.

Assessment of the Relationship between Sleep Disorders and Circadian Type in Nurses with Shift and Daytime Work

Background and Objective: Chronotypes vary in different people, and the daily function outside of the framework of this rhythm can affect the quality of work. This study aimed to investigate the association between sleep disorders and chronotypes among the shift and day work nurses. Materials and Methods: This cross-sectional study was performed among nurses in two teaching hospitals in Mash-had, Iran, during 2016-2017. A total of 180 randomly-selected nurses were divided into shift work and day work groups. Participants completed demographic information form, Circadian Type Inventory (CTI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI). Results: A total of 180 female nurses (90 participants in each group) with a mean age of 35.62 ± 4.07 years were stud-ied. The prevalence of rigid circadian rhythm in the day work group (93.3%) was significantly (P = 0.004) higher than shift work group (78.9%). However, the groups did not show any significant difference regarding the languid/vigorous (LV) index of the CTI (P = 0.080). There was a significant difference in the mean score of CTI between individuals with rigid and flexible circadian rhythms in the shift work group (P = 0.021). Conclusion: In the present study, although there was no association between circadian type and sleep problems includ-ing insomnia and daytime sleepiness in shift work nurses, we observed the capability of coping with working in the rotating shifts in nurses with flexible circadian rhythms.

Evaluating the Effects of Different Sleep Supplement Modes in Attenuating Metabolic Consequences of Night Shift Work Using Rat Model.

PurposeTo study the effects of chronic-simulated night shift work using the rat model and examines if a particular sleep supplement mode could be better in alleviating the effects.MethodsThe male Wistar rats were randomly divided into the control (CTL: 8 rats) and night shift work (NW: 24 rats) groups of rats. Based on the sleep supplement strategy, the NW group was further segregated into three subgroups (8 rats each); late sleep supplement group (LSS), early sleep supplement group (ESS), and intermittent sleep supplement group (ISS). Sleep deprivation was achieved using the standard small-platform-over water method. Parameters such as animal body weight and food intake were measured daily. The intraperitoneal glucose tolerance test, fasting plasma insulin concentration, insulin resistance index and insulin sensitivity were measured twice, in the 4th and 8th weeks of the study. Plasma corticosterone concentration and pathological changes in islets (insulitis) were measured at the end of the 8th week.ResultsIn NW group, night work resulted in a gain of body weight and albeit lower than that of the CTL group. NW rats also had higher food intake, showed impaired glucose metabolism and higher plasma corticosterone concentration. The sleep supplement experiments suggested that compared to the other modes, intermittent sleep supplement had significantly low changes in the body weight, glucose metabolism and the islet cells.ConclusionSimilar to previous studies, we also found that night shift work adversely impacts the body weight and glucose metabolism in rats. However, upon evaluating different sleep supplement strategies, we found the intermittent sleep supplement strategy to be most effective.

The Effects of Circadian Rhythm Disruption on Mental Health and Physiological Responses among Shift Workers and General Population.

Background: The effect of circadian disruption on the bio-psychological clock system has been widely studied. However, the mechanism and the association of circadian rhythm disruption with mental health and physiological responses are still unclear. Therefore, this study was conducted to investigate the effects of circadian rhythm disruption on mental health and physiological responses among shift workers and the general population. Methods: A total of 42 subjects participated in this quasi-experimental study. Participants were divided into a group of shift workers (n = 20) and a general population group (n = 22). Polysomnography tests, blood tests (cortisol, triglycerides and glucose), and psychological tests (Abbreviated Profile of Mood States, General Health Questionnaire-28, Working Memory and Processing Speed Indexes of the Wechsler Adult Intelligent Scale (WAIS-IV) were used to examine the effects of circadian rhythm disruption. Results: The results showed a significant relationship between circadian rhythm disruption and mood (r = 0.305, p < 0.05). The findings of this study also indicated that there was a significant effect of circadian rhythm disruption on mood (F(2,40) = 8.89, p < 0.001, η2 =0.182), processing speed (F(2,40) = 9.17, p < 0.001, η2 = 0.186) and working memory (F(2,40) = 4.963, p < 0.01, η2 = 0.11) in shift workers and the general population. Conclusions: Our findings showed that circadian rhythm disruption affects mood and cognitive performance, but it does not significantly affect psychological wellbeing and physiological responses. Future studies are warranted to examine moderator and mediator variables that could influence the circadian rhythm disruption.

Evaluating the quality and duration of sleep using actigraphy in petroleum industry shift workers

IntroductionIncreased use of shift work has led to more and more people working outside a traditional daytime schedule. Currently, approximately 20% of the labor force in developed countries is shift workers. Shift work can have devastating effects on employees’ quality of life and sleep, leading to negative consequences for individuals and their families. This study evaluates the effect of different shift schedules (seven days/seven nights, fixed-day or fixed-night, and stand-by shift) on the sleep of oil rig shift workers. Participants and methodsIn this cross-sectional study, 43 offshore workers from the National Iranian Drilling Company were enrolled. Subjects were asked to complete a questionnaire package consisting of the Epworth Sleepiness scale and Pittsburgh Sleep Quality Index (PSQI). Changes in sleep patterns were measured using actigraphy for different shift schedules. ResultsThe mean age of the participants was 35.9 ± 7.9 years and the mean tenure with the drilling company was 10 ± 6.8 years. The mean total sleep time was 353 ± 58 min. The seven day/seven night shift workers had less total sleep time than the other three groups of shift workers. The mean PSQI and Epworth Sleepiness scale scores were 6.77 ± 3.1 and 7.49 ± 4.3, respectively. Twelve shift workers (27%) were diagnosed with shift work disorder in the current study and 31 participants had poor sleep quality according to PSQI score (≥5). ConclusionPoor sleep quality is common in oil rig shift workers. Further research is needed to evaluate sleep problems in oil rig shift workers.

The prevalence of excessive sleepiness is higher in shift workers than in patients with obstructive sleep apnea.

Excessive daytime sleepiness (EDS) is a common feature among shift workers as well as in obstructive sleep apnea (OSA) patients. There are several important accidents related to sleep disturbances causing EDS. The aim of this study was to evaluate EDS in a group of shift workers (regular rotating) from civil aviation and to compare them with OSA patients (n=300) and with a group of regular workers (RW) (n=140). Our sample was composed of 730 working-age individuals (aged 18-67years). The regular rotating shift workers (SW) sample was composed of 290 aeronautical mechanics. EDS was evaluated with the Epworth Sleepiness Scale (ESS) and defined as a score≥11. The prevalence value obtained for the EDS of RW was 37.1%, for SW it was 60.7% and for OSA patients it was 40.7%. A logistic regression model for EDS in a subsample composed of men and matched for age and BMI, controlling for self-reported sleep duration, showed an increased risk of EDS for SW (OR=3.91, p=.001), with the RW group as reference. OSA patients did not differ from RW on EDS levels. This study emphasizes the presence of EDS in a shift work group of civil aviation professionals, which exceeded the EDS level of a positive control group of OSA patients. Sleep hygiene education for companies' workers and management is important and mitigation strategies should be implemented to reduce excessive sleepiness among workers.

Night Shift Work-A Risk Factor for Breast Cancer.

Shift work is considered a risk factor for some health problems. This study aimed to determine whether night shift work is a significant factor for breast cancer risk. The case–control study was conducted from 2015–2019 in the Łódź region. The case group included 494 women diagnosed with malignant breast cancer; the control group included 515 healthy women. The research tool was an anonymous questionnaire. In the case group, the percentage of women working shift work was 51.9%, whereas in the control group, it was 34.1% (OR = 2.08 (95% CI: 1.61; 2.69)). A more insightful examination of shift work showed that only night work has a significant impact on breast cancer (OR = 2.61 (95% CI: 1.94; 3.53)). Even after considering the effect of other possible cancer factors (like high BMI, smoking, early menstruation, late menopause, pregnancy history, age, place of living, education), the odds of developing cancer were twice as high in the group of shift workers (OR = 2.20 (95% CI: 1.57; 3.08)). Considering a significantly higher risk of cancer among people working at night and a high percentage of such employees in Poland, the government should consider special action in the prophylactic treatment of cancers.