Lifestyle behaviors among Canadian nurses working night shifts in the COVID-19 era: a pilot study.

Abstract: Working night shifts has been associated with negative mental health consequences such as depression, anxiety, and sleep problems. The objectives of this study were to determine the lifestyle behaviors (prevalence of nicotine, caffeine, cannabis, sleep-promoting medication, and alcohol use) and the association between job stress, sleep quality, anxiety, and depression among registered nurses working night shifts in the Canadian province of Saskatchewan in the COVID-19 era. Twenty-two registered nurses ranging from ages 25-65 that work permanent or rotating night shifts participated in an online survey from April 11th to July 15th, 2022. The results showed a strong positive association between sleep disturbance, and depression r (19) = 0.50, [p = 0.029, 95% CI, 0.06, 0.78]. A positive correlation was found between higher levels of reported anxiety and sleep disturbance r (19) = 0.69, [p = 0.001, 95% CI, 0.34, 0.87]. There was a positive correlation between depression and occupational exhaustion r (17) = 0.56, [p = 0.021, 95% CI, 0.10, 0.82]. Anxiety was significantly related to occupational exhaustion r (17) = 0.65, [p = 0.005, 95% CI, 0.24, 0.86] and depersonalization r (17) = 0.52, [p = 0.005, 95% CI, 0.06, 0.80], but not significantly related to personal accomplishment r (17) = -0.34, [p = 0.185, 95% CI, -0.70, 0.17]. In conclusion, a sample of Canadian nurses working night shifts in the province of Saskatchewan during the COVID-19 pandemic showed a significant positive relationship among sleep disturbance, anxiety, and depression. Furthermore, most nurses reported using at least one or more of the following substances: sleep-promoting medication, nicotine, alcohol, and cannabis.

Metabolomic profiles in night shift workers: A cross-sectional study on hospital female nurses.

Background and aim: Shift work, especially including night shifts, has been found associated with several diseases, including obesity, diabetes, cancers, and cardiovascular, mental, gastrointestinal and sleep disorders. Metabolomics (an omics-based methodology) may shed light on early biological alterations underlying these associations. We thus aimed to evaluate the effect of night shift work (NSW) on serum metabolites in a sample of hospital female nurses. Methods: We recruited 46 nurses currently working in NSW in Milan (Italy), matched to 51 colleagues not employed in night shifts. Participants filled in a questionnaire on demographics, lifestyle habits, personal and family health history and work, and donated a blood sample. The metabolome was evaluated through a validated targeted approach measuring 188 metabolites. Only metabolites with at least 50% observations above the detection limit were considered, after standardization and log-transformation. Associations between each metabolite and NSW were assessed applying Tobit regression models and Random Forest, a machine-learning algorithm. Results: When comparing current vs. never night shifters, we observed lower levels of 21 glycerophospholipids and 6 sphingolipids, and higher levels of serotonin (+171.0%, 95%CI: 49.1-392.7), aspartic acid (+155.8%, 95%CI: 40.8-364.7), and taurine (+182.1%, 95%CI: 67.6-374.9). The latter was higher in former vs. never night shifters too (+208.8%, 95%CI: 69.2-463.3). Tobit regression comparing ever (i.e., current + former) and never night shifters returned similar results. Years worked in night shifts did not seem to affect metabolite levels. The Random-Forest algorithm confirmed taurine and aspartic acid among the most important variables in discriminating current vs. never night shifters. Conclusions: This study, although based on a small sample size, shows altered levels of some metabolites in night shift workers. If confirmed, our results may shed light on early biological alterations that might be related to adverse health effects of NSW.

Shift work schedule and sleep patterns in relation to incident depression: Evidence from a prospective cohort study.

This study aims to explore the joint associations of shift work and sleep patterns with incident depression. The present prospective cohort using data from UK biobank, included 220,651 participants aged 38 to 71 years recruited between 2006 and 2010. Every participant finished a self-completed touch-screen questionnaire. Hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) of incident depression were reported for shift work and sleep patterns by Cox-proportional hazard models. The average follow-up time was 12.13±1.94 years and the incidence rate of depression was 2.95 (2.89-3.02) per 1000 person-years. After fully adjustment, the participants with irregular and permanent night shifts companied by any sleep pattern were significantly associated with increased risk of incident depression compared with no shift work companied by favorable sleep patterns. The females seemed to be more vulnerable when having night shifts and unfavorable sleep patterns compared with the males. The increased risk of incident depression associated with shift work regardless of night shifts and evening/weekend shifts was not able to offset by favorable sleep patterns. The workers with unhealthy sleep patterns, especially inappropriate sleep duration and insomnia companied by shift work schedule should be paid more attention considering higher risk of depression.

Using Light to Facilitate Circadian Entrainment from Day to Night Flights.

BACKGROUND: As part of a larger project to provide recommendations regarding limitations and best practices for shifting aviators from day to night operations, a study was conducted to assess the efficacy of high energy visible (HEV) light to shift the circadian rhythm in humans. The study attempted to replicate the patterns of military aviators who could be required to shift abruptly from day to night flight operations.METHODS: Simulated flight performance and salivary melatonin levels of 10 U.S. military aviators were collected over a 3-night period using a within-subject dim light melatonin onset (DLMO) study design. Data were collected in a laboratory with participants returning home to sleep following each of the three evenings/nights of data collection. Light treatment included a single 4-h exposure of blue-enriched white light (∼1000 lux) on night 2. Data collected included melatonin levels, light exposure, sleepiness, cognitive workload, and simulated flight performance.RESULTS: The average delay in melatonin onset was 1.32 ± 0.37 h (range: 53 min to 1 h 56 min). Sleepiness (P = 0.044) and cognitive workload (P = 0.081) improved the night following the light treatment compared to the baseline. No systematic differences were identified in flight performance.DISCUSSION: The HEV light treatment successfully delayed the circadian phase of all participants even though participants' ambient light levels (including daylight) outside the laboratory were not controlled. These findings were used to develop circadian synchronization plans for aviators who are asked to transition from day to night operations. These plans will be assessed in a follow-on study in an operational unit.Shattuck NL, Matsangas P, Reily J, McDonough M, Giles KB. Using light to facilitate circadian entrainment from day to night flights. Aerosp Med Hum Perform. 2023; 94(2):66-73.

"Mars Bar and a Tin of Red Bull Kept Me and My Patients Alive": Exploring Barriers to Healthy Eating through Facebook Comments of Shiftworkers.

The negative impact of an unhealthy diet on the shiftworker population has been well-documented. However, little evidence exists on the underlying reasons for unhealthy eating behaviours and the existing barriers to healthy eating withinshiftwork environments. This qualitative study investigated the dietary behaviours reported by shiftworkers through Facebook comments. Comments were collected if they were on public shiftworker-relevant posts pertaining to dietary news or dietary information on Facebook and were posted by self-identified shiftworkers, relatives of shiftworkers, or partners of shiftworkers. A thematic analysis of the 144 comments collected generated four categories that can be used to understand the motivations for eating behaviour on-shift: what shiftworkers eat, where food is sourced from, when food is eaten, and why certain foods are chosen. Results reveal motivations, attitudes, and both internal and external barriers to healthy eating behaviours, as well as similarities and differences across shiftwork industries. Recommendations for future research include further explorations on the link between scheduled eating (e.g., time-restricted eating) and shiftwork, the impact of a rotating shift arrangements on dietary health behaviours, and the impact of interpersonal relationships on shiftworker dietary choices. Understanding these motivations will inform strategies to promote healthy eating and help understand barriers for shiftworkers.

Pilot fatigue survey: A study of the mutual influence among fatigue factors in the "work" dimension.

Background: Fatigue risk management for pilots has received increasing attention. The existing fatigue management systems have detailed descriptions of the factors and the mutual influences among the factors that affect the dimension of "sleep", which is one of the most important causes of fatigue. However, the analysis of the influencing factors of the "work" dimension of fatigue causes has not been very detailed or accurate, especially the exploration of the mutual influence among many fatigue-influencing factors in the "work" dimension. Objective: The purpose of this study was to explore the mutual influence among fatigue-influencing factors related to the "work" dimension in the analysis of pilot fatigue causes. Methods: This study designed a questionnaire on the dimension of "work" in the causes of pilot fatigue and collected a total of 270 feedback data points from international flight pilots. Based on the questionnaires and data, descriptive statistical analysis, exploratory factor analysis and confirmatory factor analysis were performed to explore the influencing factors and their mutual influences on the "work" dimension of pilot fatigue. Results: There is a strong, mutual influence relationship among the fatigue causes of long-haul flight pilots - working status, working conditions and working schedules - in the dimension of "work". The workload only has a strong correlation with the working schedule, and the interaction relationships with the working status or working conditions are weak. Conclusion: This study analyses the mutual influence among the influencing factors of the "work" dimension of pilot fatigue, and we expect to provide empirical data for pilot fatigue risk management and to help improve fatigue risk management systems.

Do changes in working hours increase stress in Japanese white-collar workers?

Introduction: High stress at work is associated with negative health outcomes for workers, making stress prevention a critical challenge. Overtime work is an influential stress factor. This study, therefore, aimed to longitudinally evaluate how stress increased depending on changes in working hours among Japanese white-collar workers. Methods: We targeted 3,874 participants who were full-time workers and were recognized as having low stress in a web-based cohort in 2018 (T1) and 2019 (T2). We performed univariate and multivariate logistic regression with the following variables: years of experience, years of education, medical background, income, and roommates. Results: We observed a greater increase in stress among female who worked 41-50 h per week at T1 and more than 50 hours per week at T2, and those who worked more than 50 h per week at T1 and 35-40/41-50 h per week at T2, compared to those who worked 41-50 h per week both at T1 and T2, with odds ratios (ORs) and 95% confidence intervals (95% CI) of OR = 2.09, 95% CI (1.18, 3,70); OR =1.86, 95% CI (1.14, 3.03), respectively. However, no association between change in working hours and stress was found among male. Discussion: These results show that reducing stress requires decreasing working hours as well as identifying factors that lead to high stress.

Alterations in Pregnenolone and Testosterone Levels in Male Shift Workers.

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.

Shift Work and Sleep Disturbance in the Oil Industry.

BACKGROUND: Rotating shift work is common in high-hazard industries, despite documented associations with sleep disturbance and impairment. In the oil industry, where rotating and extended shift schedules are used to staff safety-sensitive positions, work intensification and increasing overtime rates have been broadly documented over the last few decades. Research on the impacts of these work schedules on sleep and health has been limited for this workforce. METHODS: We examined sleep duration and quality among rotating shift workers in the oil industry and explored associations between schedule characteristics, sleep, and health outcomes. We recruited hourly refinery workers from the West and Gulf Coast oil sector members of the United Steelworkers union. FINDINGS: Impaired sleep quality and short sleep durations were common and associated with health and mental health outcomes common among shift workers. Shortest sleep durations followed shift rotations. Early rise and start times were associated with shorter sleep duration and poorer sleep quality. Drowsiness and fatigue-related incidents were common. CONCLUSION/APPLICATION TO PRACTICE: We observed lower sleep duration and quality and increased overtime in 12-hour rotating shift schedules. These long workdays with early start times may reduce available hours for quality sleep; here they were associated with reduced exercise and leisure activity which correlated with good sleep. This safety-sensitive population appears severely impacted by poor sleep quality, which has broader implications for process safety management. Later start times, slower rotation, and a reconsideration of two-shift schedules are interventions to consider for improving sleep quality among rotating shift workers.

Association between Shift Work Schedules and Cardiovascular Events in a Multi-Ethnic Cohort.

BACKGROUND: Shift work is known to increase the risk of cardiometabolic diseases and mortality. We investigate the relationship between shift work schedules and cardiometabolic risk factors (smoking, hypertension, and obesity) and their association with cardiometabolic diseases (diabetes and cardiovascular diseases) in a multi-ethnic population from Singapore. METHODS: 2469 participants from the Singapore-based Multi-Ethnic Cohort underwent physical and clinical assessments. Shift work schedules (morning, evening, night, and mixed) were assessed using a validated questionnaire. RESULTS: Among shift workers, night shift workers had a significantly higher prevalence of smoking (54.5%), diabetes (27.3%), and cardiovascular events (14.1%). Compared to non-shift workers, workers in the night (OR = 2.10, 95%CI: 1.26-3.41) and mixed (OR = 1.74, 95%CI: 1.22-2.48) shift groups were more likely to be current smokers. A significant association between shift duration and smoking (OR = 1.02, 95%CI: 1.00-1.03) was also observed, with longer shift duration (in years) leading to an increase in smoking behavior. No significant associations were found between shift work schedules and hypertension, obesity (BMI), diabetes, and cardiovascular disease, as well as other cardiometabolic risk factors and diseases. CONCLUSION: This study found that shift schedules and shift duration were most strongly associated with smoking status after covariate adjustments (age, gender, ethnicity, socioeconomic status, and work arrangement), with night and mixed shift types being strongly associated with current smoker status. As smoking is a modifiable risk factor for cardiometabolic disease, employers of shift workers should increase work-based health interventions to control smoking and promote a healthier workforce.

Rotating Night Shift Work and Bladder Cancer Risk in Women: Results of Two Prospective Cohort Studies.

Bladder cancer is the sixth most common cancer in the United States. Night shift work has previously been linked with cancer risk. Whether there is an association between rotating night shift work and bladder cancer in women has not been studied previously. Eligible participants in the Nurses' Health Study (NHS, n = 82,147, 1988-2016) and Nurses' Health Study II (NHSII, n = 113,630, 1989-2015) were prospectively followed and a total of 620 and 122 incident bladder cancer cases were documented during the follow-up of NHS and NHSII, respectively. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for bladder cancer incidence. We observed a significantly increased risk of bladder cancer among women with >5 years of night shift work history compared with women who never worked rotating night shifts in NHS (HR = 1.24; 95%CI = 1.01-1.54, p for trend = 0.06), but not in the pooled NHS and NHS II (HR = 1.18; 95%CI = 0.97-1.43, p for trend = 0.08). Secondary analyses stratified by smoking status showed no significant interaction (p = 0.89) between the duration of rotating night shift work and smoking status. In conclusion, our results did not provide strong evidence for an association between rotating night shift work and bladder cancer risk.

Controlled light exposure and intermittent fasting as treatment strategies for metabolic syndrome and gut microbiome dysregulation in night shift workers.

The mammalian circadian clocks are entrained by environmental time cues, such as the light-dark cycle and the feeding-fasting cycle. In modern society, circadian misalignment is increasingly more common under the guise of shift work. Shift workers, accounting for roughly 20% of the workforce population, are more susceptible to metabolic disease. Exposure to artificial light at night and eating at inappropriate times of the day uncouples the central and peripheral circadian clocks. This internal circadian desynchrony is believed to be one of the culprits leading to metabolic disease. In this review, we discuss how alterations in the rhythm of gut microbiota and their metabolites during chronodisruption send conflicting signals to the host, which may ultimately contribute to disturbed metabolic processes. We propose two behavioral interventions to improve health in shift workers. Firstly, by carefully timing the moments of exposure to blue light, and hence shifting the melatonin peak, to improve sleep quality of daytime sleeping episodes. Secondly, by timing the daily time window of caloric intake to the biological morning, to properly align the feeding-fasting cycle with the light-dark cycle and to reduce the risk of metabolic disease. These interventions can be a first step in reducing the worldwide burden of health problems associated with shift work.

Sleep in Residents: A Comparison between Anesthesiology and Occupational Medicine Interns.

Sleep deprivation is a significant risk to the health and judgment of physicians. We wanted to investigate whether anesthesiology residents (ARs) who work only one night shift per week have different physical and mental health from occupational medicine residents (OMRs) who do not work at night. A total of 21 ARs and 16 OMRs attending a university general hospital were asked to wear an actigraph to record sleep duration, heart rate and step count and to complete a questionnaire for the assessment of sleep quality, sleepiness, fatigue, occupational stress, anxiety, depression and happiness. ARs had shorter sleep duration than OMRs; on average, they slept 1 h and 20 min less (p < 0.001). ARs also had greater daytime sleepiness, a higher heart rate and lower happiness than OMRs. These results should be interpreted with caution given the cross-sectional nature of the study and the small sample size, but they are an incentive to promote sleep hygiene among residents.

Association Between Night Shift and Hypertension: A Cross-Sectional Study in Chinese Adults.

OBJECTIVE: The purpose of this study was to explore the effect of night-shift work on the risk of hypertension for improving workers' health. METHODS: A total of 10,038 Chinese participants were constituted in the cross-sectional study. Logistic regression and restricted cubic spline were used to estimate the effect of night shift on hypertension. RESULTS: There were higher odds of having hypertension in any night-shift workers (odds ratio [OR], 1.16 [95% confidence interval, 1.03-1.30]) when compared with day workers. Having 5 to 10 night shifts per month were significantly more likely to be hypertensive (OR, 1.19 [95% confidence interval, 1.03-1.38]). The OR for hypertension increased as the number of night shifts increased as the result of the restricted cubic spline. CONCLUSIONS: Our results support the hypothesis that night shift is associated with an elevated risk of hypertension.

A Survey Exploring How Watch Officers Manage Effects of Sleep Restrictions during Maritime Navigation.

Merchant marine officers work shifted hours with a sometimes very tiring work/rest rhythm that can lead to sleep restrictions and increased sleepiness during navigation. The aim of this study is to assess the risk of sleep deprivation-related sleepiness during navigation and the factors contributing to this risk. A second objective is to evaluate the use and effectiveness of sleepiness countermeasures. An online quantitative survey of 43 questions was conducted on 183 French maritime officers. A total of 39.9% of the participants experienced at least occasionally severe sleepiness and 29% had fallen asleep during navigation. A total of 42.6% reported not being able to experience enough sleep on board. Sleep requirements were affected by time spent on board, area of activity, and watch system. Sleepiness was more common during monotonous than demanding sailing. Officers frequently use caffeine, as well as vigilance-enhancing activities that they consider effective, which are not yet validated, (i.e., social interactions). However, they are not inclined to seek replacements in case of severe sleepiness. Sleep deprivation is common among maritime officers and leads to the risk of severe sleepiness while operating the vessel, with few effective countermeasures available. Strategies used for sleep management and sleepiness prevention should focus more on sleep duration, safety culture, and improving countermeasures to sleepiness.

Associations between the Timing and Nutritional Characteristics of Bedtime Meals and Sleep Quality for Nurses after a Rotating Night Shift: A Cross-Sectional Analysis.

The purpose of this study was to investigate the associations of the timing and nutritional characteristics of bedtime meals with sleep quality in nurses after rotating night shifts. In total, 128 nurses from a university hospital in South Korea participated in this cross-sectional study. Data were collected on the first night of two or three consecutive routine night shifts. Participants recorded all food eaten before going to bed after work. An accelerometer was used to objectively measure sleep quality, and subjective sleep quality was assessed by self-report using the Korean version of the Verran and Snyder-Halpern Sleep Scale. The associations of timing and nutritional characteristics of bedtime meals with sleep quality after night shifts were analyzed using multivariate linear regression. A short time interval between meals and sleep was associated with longer objectively measured total sleep time (ß = -0.37, p = 0.002), and the proportion of protein in meals was associated with better objectively measured sleep efficiency (ß = 0.31, p = 0.007). The shorter the time interval, the better the subjective sleep quality (ß = -0.23, p = 0.048), and high-calorie meals were positively associated with subjective sleep quality (ß = 0.23, p = 0.043). Based on our findings, we encourage nurses to have protein-rich meals after night shifts and reduce the delay between meals and sleep. Although high-calorie meals were shown to have a positive effect on subjective sleep quality, it is necessary to confirm this effect through additional research.

Exercise, diet, and sleep habits of nurses working full-time during the COVID-19 pandemic: An observational study.

BACKGROUND: Healthy diet, exercise, and sleep practices may mitigate stress and prevent illness. However, lifestyle behaviors of acute care nurses working during stressful COVID-19 surges are unclear. PURPOSE: To quantify sleep, diet, and exercise practices of 12-hour acute care nurses working day or night shift during COVID-19-related surges. METHODS: Nurses across 10 hospitals in the United States wore wrist actigraphs and pedometers to quantify sleep and steps and completed electronic diaries documenting diet over 7-days. FINDINGS: Participant average sleep quantity did not meet national recommendations; night shift nurses (n = 23) slept significantly less before on-duty days when compared to day shift nurses (n = 34). Proportionally more night shift nurses did not meet daily step recommendations. Diet quality was low on average among participants. DISCUSSION: Nurses, especially those on night shift, may require resources to support healthy sleep hygiene, physical activity practices, and diet quality to mitigate stressful work environments.

Shift work organization on nurse injuries: A scoping review.

BACKGROUND: Extended work hours and shift work can result in mistimed sleep, excessive sleepiness, and fatigue, which affects concentration and cognition. Impaired concentration and cognition negatively affect employee safety. OBJECTIVE: To examine the evidence of the impact of shift work organization, specifically work hours and scheduling, on nurse injuries including needlestick and sharps injuries, drowsy driving and motor vehicle crashes, and work-related accidents causing a near miss or actual injury to the nurse. METHODS: A scoping review was conducted using search results from five bibliographic databases. RESULTS: Through database searching, 7788 articles were identified. During the title and abstract screening, 5475 articles were excluded. Full text screening eliminated 1971 articles. During the data extraction phase, 206 articles were excluded leaving 34 articles from 14 countries in the scoping review. The results of the review suggest a strong association in nurses between long work hours and overtime and an increased risk for needlestick and sharps injuries, drowsy driving and motor vehicle crashes, and other work-related accidents. Rotating shifts increase the risk for needlestick and sharps injuries and other work-related accidents while night and rotating shifts increase the risk for drowsy driving and motor vehicle crashes. CONCLUSIONS: Proper management of work hours and scheduling is essential to maximize recovery time and reduce or prevent nurse injuries. Nurse leaders, administrators, and managers, have a responsibility to create a culture of safety. This begins with safe scheduling practices, closely monitoring for near miss and actual nurse injuries, and implementing evidence-based practice strategies to reduce these occurrences.

Sleep Traits, Night Shift Work and Lung Cancer Risk among Women: Results from a Population-Based Case-Control Study in France (The WELCA Study).

Circadian rhythm disruption due to night shift work and/or sleep disorders is associated with negative health outcomes including cancer. There is only scant evidence of an association with lung cancer, unlike breast and prostate cancer. We explore the role of sleep disorders and night shift work in lung cancer risk among women in a population-based case-control study, including 716 lung cancer cases and 758 controls. Multivariable logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) associated with sleep duration per day (<7 h, 7−7.9 h, ≥8 h), a summary index of sleep disorders, chronotype, and night shift work exposure metrics. When compared to women with an average sleep duration of 7−7.9 h per day, the OR was 1.39 (95% CI 1.04−1.86) in long sleepers (≥8 h) and 1.16 (95% CI 0.86−1.56) in short sleepers (<7 h). Overall, lung cancer was not associated with the sleep disorder index, nor with night shift work, regardless of the duration of night work or the frequency of night shifts. However, elevated OR associated with the sleep disorder index were found in the subgroup of current smokers. The U-shaped association of lung cancer with sleep duration was more particularly pronounced among women who worked at night ≥5 years. Our findings suggested that sleep patterns are associated with lung cancer risk in women with a potential modifying effect by night shift work duration or tobacco smoking.