Sex and race disparities in the association between work characteristics and vitamin D deficiency: findings from the National Health and Nutrition Examination Survey, 2005-2010.

OBJECTIVES: Vitamin D deficiency is highly prevalent worldwide; however, few large population-based studies have examined occupational risk factors. We examined associations between shift work, work schedule, hours worked, outdoor work, occupation and serum 25-hydroxyvitamin D (25(OH)D) levels in the US working population. METHODS: This cross-sectional study included 8601 workers from the 2005-2010 National Health and Nutrition Examination Survey (NHANES) cycles. NHANES occupational data were supplemented with measures of outdoor work from the Occupational Information Network. Serum 25(OH)D concentration in nanomoles per litre (nmol/L) was categorised as sufficient (≥75), insufficient (50-<75), moderately deficient (30-<50) and severely deficient (<30). Age-adjusted weighted multinomial and binary logistic regression were used to examine associations between work-related factors and vitamin D status with sex-race/ethnicity stratification. RESULTS: Shift workers had higher odds of severe vitamin D deficiency compared with day workers (OR: 1.64, 95% CI 1.22 to 2.19). Compared with those in white-collar occupations, those in natural resources were less likely to be deficient (OR: 0.31, 95% CI 0.19 to 0.52), while those in production were more likely to be deficient (OR: 2.25, 95% CI 1.48 to 3.43). Women working ≥40 hours/week compared with <40 hours/week were more likely to be moderately deficient (OR: 1.30, 95% CI 1.06 to 1.59). Black women working in sales were more likely to be deficient than those in management (OR: 1.53, 95% CI 1.03 to 2.27). Mexican American men working nights had the highest odds of deficiency (OR: 2.64, 95% CI 1.38 to 5.06). CONCLUSIONS: Work-related factors were associated with vitamin D status and there were race/ethnicity and sex differences. Targeted vitamin D screening and supplementation interventions may reduce these disparities.

Relationship between shift type and sleep quality in rotating-shift nurses with chronotype as a moderator variable.

BACKGROUND: Rotating-shift nurses are susceptible to sleep disorders due to numerous factors, such as their biological clock, emotions, and age. At present, a lack of research exists on whether chronotype and shift type jointly influence the sleep quality of nurses. AIM: To verify whether chronotype is a moderator variable of the relationship between shift type and sleep quality in nurses in order to provide empirical evidence for future mental and physical health improvement. METHOD: Clinical rotating-shift nurses at a medical center in northern Taiwan were recruited as participants between November 1, 2023, and December 13, 2023. All of the nurses were working a monthly rotating shift schedule. Hierarchical multiple regression analysis was employed to investigate whether the influence of shift type on sleep quality in nurses varied with chronotype. The STROBE checklist was used for reporting this study. RESULTS: The participants were 255 rotating-shift nurses in this study. Hierarchical multiple regression results revealed that rotating-shift nurses who were older (B = 0.19, p = 0.029), had greater physical fatigue (B = 0.27, p = 0.016), and had more negative emotions (B = 0.17, p = 0.011) suffered from poorer sleep quality. After controlling the above factors, we further found that chronotype indeed had moderating effects on the influence of shift type on sleep quality (B = -1.83, p = 0.049). CONCLUSIONS: This study demonstrates that early- and intermediate-type nurses are more suitable for working the day and evening shifts, whereas late-type nurses are more suitable for working the night shift. IMPLICATION FOR NURSING AND HEALTH POLICY: Coordinating chronotype with shift type will ensure that shift schedules better match the biological clocks of nurses; such individual considerations could help to improve their sleep quality.

Chronic Mealtime Shift Disturbs Metabolic and Urinary Functions in Mice: Effects of Daily Antioxidant Supplementation.

PURPOSE: Through their biological clocks, organisms on this rotating planet can coordinate physiological processes according to the time of the day. However, the prevalence of circadian rhythm disorders has increased in modern society with the growing number of shift workers, elevating the risk of various diseases. In this study, we employed a mouse model to investigate the effects of urinary rhythm disturbances resulting from dietary changes commonly experienced by night shift workers. METHODS: We established 3 groups based on feeding time and the use of restricted feeding: ad libitum, daytime, and early nighttime feeding. We then examined the urinary rhythm in each group. In addition to the bladder rhythm, we investigated changes in mRNA patterns within the tissues constituting the bladder. Additionally, we assessed the urination rhythm in Per1 and Per2 double-knockout mice and evaluated whether the injection of antioxidants modified the impact of mealtime shift on urination rhythm in wild-type mice. RESULTS: Our study revealed that a shift in mealtime significantly impacted the circadian patterns of water intake and urinary excretion. In Per2::Luc knock-in mouse bladders cultured ex vivo, this shift increased the amplitude of Per2 oscillation and delayed its acrophases by several hours. Daily supplementation with antioxidants did not influence the mealtime shift-induced changes in circadian patterns of water intake and urinary excretion, nor did it affect the modified Per2 oscillation patterns in the cultured bladder. However, in aged mice, antioxidants partially restored the urinary rhythm. CONCLUSION: A shift in mealtime meaningfully impacted the urination rhythm in mice, regardless of the presence of circadian clock genes.

The association between shift work, shift work sleep disorders and premature ejaculation in male workers.

OBJECTIVE: Shift work and Shift Work Sleep Disorder (SWSD) are known to affect the secretion of several neurotransmitters and hormones associated with premature ejaculation (PE). However, their specific influence on the regulation of male ejaculation remains unclear. This study explores the relationship between shift work, SWSD, and PE. METHODS: From April to October 2023, a cross-sectional survey was conducted across five regions of China to explore the work schedules, sleep quality, and sexual function of male workers. Participants' sleep quality was evaluated using a validated SWSD questionnaire, and their erectile function and ejaculatory control were assessed with the International Inventory of Erectile Function (IIEF-5) scores and Premature Ejaculation Diagnostic Tool (PEDT) scores, respectively. Univariate and multivariate linear regression analyses were employed to identify risk factors associated with PE. Confounders were controlled using multiple regression models, and clinical prediction models were developed to predict PE onset and assess the contribution of risk factors. RESULTS: The study included 1239 eligible participants, comprising 840 non-shift workers and 399 shift workers (148 with SWSD and 251 without SWSD). Compared to non-shift working males, those involved in shift work (ß 1.58, 95% CI 0.75 - 2.42, p < 0.001) and those suffering from SWSD (ß 2.86, 95% CI 1.86 - 3.85, p < 0.001) they had significantly higher PEDT scores. Additionally, we identified daily sleep of less than six hours, depression, anxiety, diabetes, hyperlipidemia, frequent alcohol consumption (more than twice a week), and erectile dysfunction as risk factors for PE. The predictive model for PE demonstrated commendable efficacy. CONCLUSION: Both shift work and SWSD significantly increase the risk of premature ejaculation, with the risk magnifying in tandem with the duration of shift work. This study reveals the potential impact of shift work and SWSD on PE and provides new theoretical foundations for the risk assessment and prevention of this condition.

Factors leading to excessive fatigue in nurses - a three-year follow-up study.

BACKGROUND: Global nursing shortages necessitate the identification of mitigatable factors that may reduce nursing absence and turnover. Fatigue has been shown to be associated with these issues. This study aimed to identify factors leading to development of or recovery from excessive fatigue in nurses as these can offer actionable avenues for protecting nurses against fatigue or supporting fatigue recovery. METHODS: A longitudinal study among nurses randomly sampled from the Norwegian Nurse's Organization. The Chalder Fatigue Questionnaire measured fatigue. Dichotomized scoring was used, with scores ≥ 4 considered excessive fatigue. The study included questions on shift work schedules, psychosocial work characteristics, sleep, body mass index, physical activity, caffeine, alcohol, mental health, etc. Two sets of logistic regression analysis were conducted (one for development of and one for recovery from excessive fatigue), evaluating how changes in work, lifestyle and health between baseline (2015) and follow-up (2018) affected first, odds of development of excessive fatigue and second, odds of recovery from excessive fatigue. RESULTS: Among 1,311 included nurses, 21.6% maintained, 13.3% developed, and 18.0% recovered from excessive fatigue (2015-2018). Within work characteristics, increased psychological work demands were associated with development of excessive fatigue OR = 1.77 (CI = 1.11-2.82). Several work characteristics were associated with recovery from excessive fatigue, including decreased decision latitude (OR = 0.39; CI = 0.19-0.82) and increased coworker support (OR = 1.90; CI = 1.11-3.24). Shift work variables were not associated with fatigue outcomes. Amongst lifestyle factors, changes in sleep duration, obesity, and exercise were significant. Notably, developing inappropriate sleep duration (OR = 2.84; CI = 1.47-5.48) increased odds of developing excessive fatigue, while maintaining inappropriate sleep duration (< 6 h or > 8 h) (OR = 0.19; CI = 0.54-0.65) decreased odds of recovering. All assessed health conditions (depression, anxiety, insomnia, and shift work disorder) were related to development of (ORs 2.10-8.07) or recovery from (ORs 0.10-0.50) excessive fatigue. Depression, for example, increased odds of development of (OR = 8.07; CI = 2.35-27.66) and decreased odds of recovery (OR = 0.10; CI = 0.04-0.26) from excessive fatigue. CONCLUSIONS: Changes in lifestyle factors, health conditions, and psychosocial work factors were associated with development of and recovery from excessive fatigue. Sleep and psychosocial work factors played important roles. We found no relationship with shift work schedules.

Shift work effects on incident neuropsychiatric disorders and shift work tolerance.

BACKGROUND: Shift work is associated with susceptibility to several neuropsychiatric disorders. This study aims to investigate the effect of shift work on the incidence of neuropsychiatric disorders, and highlighting how individual variability may influence the association. METHODS: UK Biobank participants with employment information were included. Cox survival was conducted in main and subgroup analyses. Correlation analyses explored the impact of shift work on brain structures, and mediation analyses were performed to elucidate the shared underlying mechanisms. Shift work tolerance was evaluated through survival analyses contrasting the risks associated with five neuropsychiatric disorders in shift versus non-shift workers across different demographic or occupational strata. RESULTS: The analysis encompassed 254,646 participants. Shift work was associated with higher risk of dementia (HR 1.29, 95 % CI 1.10-1.52), anxiety (1.08, 1.01-1.15), depression (1.29, 1.22-1.36), and sleep disorders (1.18, 1.09-1.28), but not stroke (p = 0.20). Shift work was correlated with decreasing volume of various brain regions, particularly in thalamus, lateral orbitofrontal, and middle temporal. Mediation analysis revealed that increased immune response and glucose levels are common pathways linking shift work to these disorders. We observed diversity in shift work tolerance across different individual characteristics, among which socioeconomic status and length of working hours were the most essential. LIMITATIONS: Self-reported employment information may cause misclassification and recall bias. And since we focused on the middle-aged population, the conclusions may not be representative of younger or older populations. CONCLUSIONS: Our findings indicated the need to monitor shift worker health and provide personalized management to help adapt to shift work.

Association of sleep duration with excess risk of dementia among shift workers in the UK biobank: a population-based cohort study.

BACKGROUND: Shift work was associated with elevated dementia risk. Definitive guidelines for sleep duration among shift workers have not been proposed. We aimed to identify sleep durations associated with elimination of excess dementia risk in shift workers. METHODS: 285,213 dementia-free UK Biobank participants at baseline, aged 38-71 years, were enrolled between 2006 and 2010 and followed up through 2022 in this cohort study. Cox proportional hazards models were used to examine the associations between shift work, sleep duration, and risk of dementia. RESULTS: The 285,213 participants included 49,079 shift workers and 236,134 non-shift workers. Over a median follow-up of 13.8 years, 1887 dementia cases were documented. Current shift workers had significantly higher dementia risk than non-shift workers (hazard ratio [HR] 1.26; 95% CI 1.11-1.42). However, this excess risk was eliminated in shift workers with 8 h of sleep (HR 1.02; 95% CI 0.80-1.29). Analysis of shift work frequency indicated that "sometimes" and "usually/always" shift work were associated with increased dementia risk compared to that of non-shift workers, but excess dementia risk was eliminated in members of either frequency group receiving 8 h of sleep ("sometimes", HR 1.05; 95% CI 0.75-1.48; "usually/always", HR 0.98; 95% CI 0.70-1.35). Both "non-night shift" and "night shift" workers showed increased dementia risk compared to non-shift workers. Workers with 8 h of sleep mitigated the excess risk (HR 1.13; 95% CI 0.84-1.53 and HR 0.86; 95% CI 0.59-1.26, respectively). CONCLUSION: 8-h sleep may eliminate excess dementia risk among shift workers, suggesting a potentially effective dementia prevention guideline for shift workers.

Factors facilitating and hindering the implementation of digital sleep coaching for bus drivers.

Improving fatigue management is critical to the occupational safety of professional drivers. We aimed to identify the factors that facilitated or hindered the implementation of digital sleep coaching in bus companies and to explore bus drivers' experiences with it. Two bus companies implemented coaching for bus drivers. Using a mixed methods design, we collected data through two workshops (n = 30 and n = 27) attended by key personnel from the organisations and through questionnaires to the drivers (n = 30). Implementation was facilitated by, for example, the flexible participation and multichannel information of coaching, and hindered by restrictions on social support due to the COVID-19 pandemic, and lack of interest and inspiring examples. On average, the drivers rated the appropriateness and the feasibility of coaching as good. However, further development could lead to wider dissemination. It would also be important to involve the key people in the organisations and stakeholders more in supporting the implementation.

Effect of shift work on dietary habits and occupational stress among nurses in a tertiary care centre: An observational study.

Introduction: Shift work comprises work hours other than 9 am to 5 pm. Healthcare jobs such as nursing have been associated with shift work, which can affect their overall health status. Due to excessive workload and instability in working hours, nurses are also prone to higher occupational stress. Materials and Methods: A descriptive study, Cornell Medical Index (CMI) questionnaire, 24-h recall method, and occupational stress score (OSS) were used to assess overall health, calorie intake, and occupational stress among nurses working in a tertiary care centre in Central India. Results: The mean age of participants in the control and study groups was 43.2 ± 6.059 years and 43.93 ± 5.20 years, respectively. Neither of the group's participants had poor nutritional status. CMI health scores revealed poor mental health among the study group. Severe occupational stress was observed in 57% of participants, and 33% had moderate occupational stress. Among the causes of occupational stress, 92% cited unfavourable work conditions, and 88% pointed out the workload. Poor peer relations and low status were cited by 77% and 57% of participants. Conclusion: This study highlights the harmful effects of shift work on health of nurses. These negative effects are usually linked to poor diet and stress, which can be induced by overwork, poor sleep, or both. This study found that high workload is the main cause of occupational stress. Sleep disruption, lack of exercise and excess work load are major contributors for occupational stress and unhealthy eating habits. More awareness regarding importance of good diet and stress management may aid in improving health of nurses working in shifts.

Rotating shift and BMI increase among healthcare workers in a military hospital: pre- and post-pandemic analysis in Taiwan.

Background: The increasing prevalence of high body mass index (BMI) emphasizes the need for action. Understanding of BMI factors among military hospital healthcare workers remains limited. This study aims to address this gap by analyzing BMI risk factors and changes pre- and post-coronavirus 2019 pandemic among military hospital healthcare workers in central Taiwan from 2019 to 2021. Methods: Conducted at a military hospital in central Taiwan, this study analyzed anonymized health examination data from 2019 to 2021 for 483 healthcare workers. We performed generalized estimating equations to investigate trends in BMI and its association with various factors, including age, sex, job titles, military status, job tenure, work shifts, and lifestyle habits. Results: The risk of increased BMI was higher in 2021 compared to 2019 (risk ratio [RR]: 1.008, 95% confidence interval [CI]: 1.001-1.014). Individuals on rotating shifts had a higher risk of increased BMI compared to day shift workers (RR: 1.021; 95% CI: 1.008-1.035) and higher odds of obesity (odds ratio: 1.546; 95% CI: 1.099-2.175). Among obese individuals, BMI in soldiers was approximately 4.9% lower than in non-soldiers (RR: 0.951; 95% CI: 0.915-0.988). Conclusions: This study identified a significant post-pandemic increase in BMI among healthcare workers in a Taiwanese military hospital, with rotating shifts being a key risk factor for both increased BMI and obesity. Work-related factors influenced BMI changes among obese individuals, while non-work-related factors were significant for non-obese individuals. These findings highlight the broader effects of the pandemic and the specific impact of work-related factors on obese healthcare workers.

Association between Circadian Rhythm-Disturbing Factors and Metabolic Syndrome in Korean Adults: Korea National Health and Nutrition Examination Survey (2016-2020).

Background: Circadian misalignment is associated with metabolic syndrome. This study aimed to examine the association between circadian rhythm-disturbing factors and metabolic syndrome. Methods: We used data from the 7th and 8th Korea National Health and Nutrition Examination Survey conducted between 2016 and 2020, which surveyed 16,253 individuals. Circadian rhythm-disturbing factors were defined as follows: sleep duration outside the reference group (6-8 hours), irregular breakfast, shift work, and physical inactivity. The adjusted odds ratio (aOR) for metabolic syndrome was calculated based on the number of circadian rhythm-disturbing factors present in adults over the age of 19 years. Results: Among a total of 16,253 participants (mean age 48.2±15 years), metabolic syndrome was found in 5,237 participants (29.3 %). The participants were classified into three categories based on the number of circadian rhythm-disturbing factors as follows: 2,627 (15.6%) did not have any factors, 6,406 (38.13%) had one factor, and 7,220 (46.3%) had two or more factors. Participants with a single circadian rhythm-disturbing factor were 21% more likely to have metabolic syndrome (aOR, 1.21; 95% confidence interval [CI], 1.08-1.36), and participants with two or more factors were 27% more likely to have metabolic syndrome (aOR, 1.27; 95% CI, 1.12-1.43). Conclusion: Circadian rhythm-disturbing factors were significantly associated with the prevalence of metabolic syndrome in Korean adults. This finding has potential clinical implications for maintaining circadian rhythms by avoiding certain factors to prevent metabolic syndrome. Further studies are required to confirm these findings.

The relationship between night shift work, sleep patterns, psychological well-being, and mental health among Jordanian healthcare workers.

This study examines the associations between working night shifts and various outcomes, including sleep patterns, healthcare workers' sleep quality, and physical, mental, and social well-being. A descriptive cross-sectional study was conducted, where the findings revealed that night shift healthcare workers experienced poor sleep quality and pattern. In addition, night shift healthcare workers were more likely to express their intent to leave, the impact of work on their social lives, and a low level of job satisfaction. Healthcare workers showed moderate anxiety and mild depression levels. Lower job satisfaction correlated with higher anxiety and depression levels among healthcare workers, while the negative impact of working hours on social life was associated with increased anxiety and depression. Organizations should consider establishing comprehensive wellness initiatives covering work-life balance, stress management strategies, and mental health resources.

More than sleep problems? Testing five key health behaviors as reasons for quality of life issues among shift workers.

BACKGROUND: The shift work schedule is a common work arrangement that can disrupt typical sleep-wake rhythms and lead to negative health consequences. The present study aims to examine the effect of shift work on health-related quality of life (QoL) and explore potential behaviorial mediators (i.e., sleep, eating, exercise, smoking, drinking). METHODS: A cross-sectional survey was conducted among 4,449 petroleum workers in southwest China. Data on shift work status, health behaviors, and physical and mental health QoL were collected. We tested our model using path analysis and the Monte Carlo approach among 2,129 included participants. RESULTS: After adjusting for covariates, shift work did not exhibit a significant direct association with QoL. However, shift work indirectly related to poorer physical health quality of life via less frequent healthy food consumption; shift work also indirectly related to poorer mental health QoL via both less frequent healthy food consumption and physical exercise. No significant indirect effects were found via sleeping, smoking, or drinking. CONCLUSIONS: Results suggest that shift work presents a challenge for QoL among Chinese petroleum workers due to their lesser engagement in two specific health behaviors: healthy eating and physical exercise. Healthy eating and exercise may present an even more prominent threat to shift workers' QoL than sleep and substance use. Strategies targeting shift work schedule as well as eating and exercise behaviors may help protect against poor QoL and adverse physical and mental health outcomes in this vulnerable group.

Effect of serial night shifts on the cognitive, psychomotor, and moral performance of residents in the department of Emergency Medicine.

OBJECTIVES: The objective was to study the effect of serial night shifts on the cognitive, psychomotor, and moral performance of emergency medicine residents of an academic Emergency Medicine Department. METHODS: This prospective case-crossover study compared emergency medicine residents' sleep time, subjective sleepiness, cognitive function, moral judgment, and psychomotor skills after 5 consecutive days versus night shifts using sleep diaries, activity monitors, and multiple performance tests. Paired t-tests and Wilcoxon signed-rank tests were used to analyze data based on normality. Correlation analysis was done using Spearman's correlation test. Subgroup analysis was also performed to find any difference based on gender and year of residency. RESULTS: Twenty-seven emergency medicine residents participated (13 males, 48.1%). The distribution across residency years was as follows: 44.4% in their first year, 25.9% in their second year, and 29.6% in their third year. Following five consecutive night shifts, total sleep duration decreased significantly from 338.1 ± 67.8 to 307.4 ± 71.0 min (p < 0.001), while subjective sleepiness scores increased from 9.6 ± 3.3 to 13.6 ± 4.6. Psychomotor performance and reaction times did not significantly differ between night and day shifts. However, working memory declined, assessed by self-paced three-back test scores (median [IQR] 517.1 [471.9-546.7] vs. 457.6 [334.4-508.8]; p = 0.034) and interference test scores (445.5 ± 59.9 vs. 407.2 ± 56.8; p < 0.001), along with moral judgment (median [IQR] 19 [18-28] vs. 15 [11-21]; p = 0.010) after serial night shifts. No correlations existed between performance measures nor differences based on gender or residency year. CONCLUSIONS: Residents sleep less following night versus day shifts, reporting the highest sleepiness levels after 5 consecutive nights. Despite this, psychomotor performance and reaction times did not significantly differ. However, considerable reductions occurred in moral judgment, working memory, and interference test performance after serial night shifts.

Acute effects of a simulated quick return on subjective sleepiness, mood, and cognitive performance: A laboratory crossover controlled trial.

Sleep loss due to short time off between shifts has been proposed as a mechanism contributing to impaired functioning in occupational settings. This laboratory crossover trial (ClinicalTrials.gov identifier: NCT05162105, N = 66) compared subjective sleepiness, mood, and cognitive performance on a day shift after an evening shift with only 8 h off between shifts (quick return, QR) to a day shift after another day shift with 16 h off between shifts (control). Results indicated higher subjective sleepiness (Karolinska Sleepiness Scale) during the QR condition compared to the control condition (p < 0.001). No significant differences were found on mood (Positive and Negative Affect Schedule) and cognitive performance (Psychomotor Vigilance- and Digit Symbol Substitution Test) between the conditions. Findings of increased subjective sleepiness corroborate previous field studies. This trial is to our knowledge the first to compare mood and cognitive performance after a QR to a longer shift transition using an experimental design. Future research should explore the effects of accumulated sleep loss associated with QRs (e.g. having several QRs within a short time period) on behavioral outcomes.

Healthily Nourished but Depleted? Is It Possible to Improve the Health of Shift Workers through Lifestyle Interventions?

The relationship between diet and health is well-researched, and there is also information regarding the effects of diet on mental health. This study aimed to investigate whether motivation to optimize lifestyles without regulations or restrictions could improve the health of rotating shift workers. In this pilot study, 18 male shift workers were randomly divided into two groups. All participants completed the Short Form Health Survey-36 questionnaire (SF-36) before the start and at the end of the study. Group I (n = 9, mean age 42 ± 6.6 y) received dietary and lifestyle information every other month for one year, and the other, Group II (n = 9 mean age 36 ± 7.3 y), one year later. All participants were motivated to follow the trained dietary recommendations and to engage in physical activity. Almost all scores had improved. Surprisingly, physical performance scores worsened, which was not expected. The impairment in mental health due to the change in ownership of the company could have been better explained. Nutritional advice over a longer period and the motivation to integrate more exercise into everyday life can potentially improve the health of rotating shift workers.

Understanding perceptions about the health effects of night working and the barriers and enablers to taking part in nutritional research: A qualitative study among night workers in England.

Working at night is associated with adverse cardiometabolic health outcomes. However, there are a lack of nutritional intervention studies conducted amongst night workers, subsequently contributing to a lack of evidence-based guidelines for night workers. The aim of The Eating on the Night Shift study was to understand how night shift workers view working at night in relation to nutritional health and wellbeing, the barriers and enablers to participate in research and what kind of guidance would be useful to them. Semi-structured qualitative interviews were conducted with a convenience sample (n = 18) of night workers based in England. The interview covered experiences of working night shifts, perceptions about night work and their health, and perceptions of and likely engagement with nutritional research. Interviews were audio recorded and transcribed verbatim. Transcripts were coded using an inductive thematic analysis approach. Of the final sample 13 were female (72%), 39% worked a rotating shift pattern and 78% had worked night shifts for 1 year or more. Four overarching themes were identified: (1) the consequences of night work on health and wellbeing, (2) eating at night means a less healthy diet, (3) working at night has wider knock-on effects on aspects of lifestyle and wellbeing and (4) nutritional research is perceived as important, but there are barriers to participation. Night workers are aware that working at night can negatively impact their diet as well as their health. Nutritional researchers need to engage with night workers when considering intervention design and implementation as well as in the development of any resultant evidence-based guidance to ensure its relevance.

Multimorbidity and its Associated Factors in Korean Shift Workers: Population-Based Cross-Sectional Study.

BACKGROUND: Multimorbidity is a crucial factor that influences premature death rates, poor health, depression, quality of life, and use of health care. Approximately one-fifth of the global workforce is involved in shift work, which is associated with increased risk for several chronic diseases and multimorbidity. About 12% to 14% of wage workers in Korea are shift workers. However, the prevalence of multimorbidity and its associated factors in Korean shift workers are rarely reported. OBJECTIVE: This study aimed to assess multimorbidity prevalence, examine the factors associated with multimorbidity, and identify multimorbidity patterns among shift workers in Korea. METHODS: This study is a population-based cross-sectional study using Korea National Health and Nutrition Examination Survey data from 2016 to 2020. The study included 1704 (weighted n=2,697,228) Korean shift workers aged 19 years and older. Multimorbidity was defined as participants having 2 or more chronic diseases. Demographic and job-related variables, including regular work status, average working hours per week, and shift work type, as well as health behaviors, including BMI, smoking status, alcohol use, physical activity, and sleep duration, were included in the analysis. A survey-corrected logistic regression analysis was performed to identify factors influencing multimorbidity among the workers, and multimorbidity patterns were identified with a network analysis. RESULTS: The overall prevalence of multimorbidity was 13.7% (302/1704). Logistic regression indicated that age, income, regular work, and obesity were significant factors influencing multimorbidity. Network analysis results revealed that chronic diseases clustered into three groups: (1) cardiometabolic multimorbidity (hypertension, dyslipidemia, diabetes, coronary heart disease, and stroke), (2) musculoskeletal multimorbidity (arthritis and osteoporosis), and (3) unclassified diseases (depression, chronic liver disease, thyroid disease, asthma, cancer, and chronic kidney disease). CONCLUSIONS: The findings revealed that several socioeconomic and behavioral factors were associated with multimorbidity among shift workers, indicating the need for policy development related to work schedule modification. Further organization-level screening and intervention programs are needed to prevent and manage multimorbidity among shift workers. We also recommend longitudinal studies to confirm the effects of job-related factors and health behaviors on multimorbidity among shift workers in the future.

Sleep duration and quality in permanent night work: an observational field study.

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.

Ecological momentary assessment of physical activity and sedentary behaviour in shift workers and non-shift workers: Validation study.

This study examined the criterion validity of an ecological momentary assessment (EMA)-reported physical activity and sedentary time compared with accelerometry in shift workers and non-shift workers. Australian workers (n = 102) received prompts through a mobile EMA app and wore the Actigraph accelerometer on the right hip for 7-10 days. Participants received five EMA prompts per day at 3-hour intervals on their mobile phones. EMA prompts sent to shift workers (SW-T) were tailored according to their work schedule. Non-shift workers (NSW-S) received prompts at standardised times. To assess criterion validity, the association of EMA-reported activities and the Actigraph accelerometer activity counts and number of steps were used. Participants were 36 ± 11 years and 58% were female. On occasions where participants reported physical activity, acceleration counts per minute (CPM) and steps were significantly higher (ß = 1184 CPM, CI 95%: 1034, 1334; ß = 20.9 steps, CI 95%: 18.2, 23.6) than each of the other EMA activities. Acceleration counts and steps were lower when sitting was reported than when no sitting was reported by EMA. Our study showed that EMA-reported physical activity and sedentary time was significantly associated with accelerometer-derived data. Therefore, EMA can be considered to assess shift workers' movement-related behaviours with accelerometers to provide rich contextual data.