The Relationship between Shift Work and Depressive Symptom

When and what you eat can be linked to circadian preference (i.e., chronotype) and occupation (e.g., shift worker). Evening chronotypes, with a later circadian preference, tend to have meals later, distribute energy intake toward the end of the day(1), and more unhealthy eating habits than morning chronotypes(2); whereas night shift work is associated with later mealtimes and poor diet quality as a result of circadian disruption due to their work(3). What is unclear is whether chronotype influences the occupation-induced dietary patterns observed in shift workers. This study aimed to investigate associations between chronotype, temporal patterns of eating and diet composition in shift and non-shift workers. Adults from shift (SW) and non-shift (N-SW) populations were recruited. A Chrononutrition Questionnaire captured chronotype, duration of eating window (DEW), time of first eating occasion (FEO) and last eating occasion (LEO) while diet composition (energy, protein, total fat, saturated fat, carbohydrate, fibre, alcohol) was extracted from 7-day food diaries. Associations between chronotype and DEW/FEO/LEO, and between DEW/FEO/LEO and diet composition were determined by Spearman Rank Coefficients. 95 participants were enrolled (N-SW: n = 39; SW: n = 56); predominantly female (71%), morning chronotype (37%), on average 40.46 ± 15.08 years with BMI of 27.04 ± 5.77kg/m2. 84 returned food diaries. Later chronotype was positively associated with later times of FEO (N-SW: r = ,50, SW: r = ,69) and LEO (N-SW: r = ,63, SW: r = ,54) on free (non-work) days (p≤.002), and longer DEW (r = ,42) and later LEO (r = ,60) on workdays for non-shift workers (p<.01). However, there were no significant differences in diet composition by day/shift type between chronotypes across the study population. On afternoon shifts, longer DEW was associated with greater energy (r = ,60) and total fat intake (r = ,60) and later LEO with greater alcohol intake (r = ,59) (p<.05). On night shifts, a longer DEW was associated with lower alcohol intake (r=-.45, p<.05). Amongst non-shift workers, later FEO was associated with lower fibre intake on workdays (r=-.58, p<.001). Additionally, non-shift workers who were later chronotypes had later LEO, which on workdays associated with lower fibre (r=-.45) and alcohol intake (r=-.43); and on work-free days, associated with lower alcohol intake (r=-.45) (p<.05). Not surprisingly, evening chronotypes across the study population had longer and/or later eating windows on work-free days (i.e., free of constraints), as did non-shift workers on workdays, while the influence of chronotype on DEW, FEO, and LEO across shifts were less clear. Hence, for shift workers, occupation appeared to be a greater driver of temporal eating patterns than chronotype. Additionally, later eating times of evening chronotypes was not associated with negative diet composition. The exception was lower fibre intake amongst non-shift workers; but regardless of chronotype, shift workers may benefit from having a shorter and earlier DEW on afternoon shifts to minimise energy, fat, and alcohol intake.

IntroductionShift work is known to reduce productivity and safety at work. Previous studies have suggested that a variety of interrelated factors, such as mood, cognition, and sleep, can affect the performance of shift workers. This study aimed to identify potential pathways from depression, sleep, and cognition to work performance in shift and non-shift workers.Material and methodsOnline survey including the Center for Epidemiologic Studies Depression Scale (CES-D), Cognitive Failure Questionnaire (CFQ), and Pittsburgh Sleep Quality Index (PSQI), as well as two items representing work mistakes were administered to 4,561 shift workers and 2,093 non-shift workers. A multi-group structural equation model (SEM) was used to explore differences in the paths to work mistakes between shift and non-shift workers.ResultsShift workers had higher PSQI, CES-D, and CFQ scores, and made more mistakes at work than non-shift workers. The SEM revealed that PSQI, CES-D, and CFQ scores were significantly related to mistakes at work, with the CFQ being a mediating variable. There were significant differences in the path coefficients of the PSQI and CES-D between shift and non-shift workers. The direct effects of sleep disturbances on mistakes at work were greater in shift workers, while direct effects of depressive symptoms were found only in non-shift workers.DiscussionThe present study found that shift workers made more mistakes at work than non-shift workers, probably because of depressed mood, poor sleep quality, and cognitive inefficiency. Sleep influences work performance in shift workers more directly compared to non-shift workers.

Objectives Shift work may alter workers' leisure-time and occupational physical activity (PA) levels, which might be one of the potential underlying mechanisms of the negative health effects of shift work. Therefore, we compared objectively measured PA levels between hospital shift and non-shift workers. Methods Data were used from Klokwerk+, a cohort study examining the health effects of shift work among healthcare workers employed in hospitals. In total, 401 shift workers and 78 non-shift workers were included, all of whom wore Actigraph GT3X accelerometers for up to seven days. Time spent sedentary, standing, walking, running, stairclimbing, and cycling during leisure time and at work was estimated using Acti4 software. Linear regression was used to compare proportions of time spent in these activities between hospital shift and non-shift workers. Results Average accelerometer wear-time was 105.9 [standard deviation (SD) 14.0] waking hours over an average of 6.9 (SD 0.6) days. No differences between hospital shift and non-shift workers were found in leisure-time PA (P>0.05). At work, shift workers were less sedentary [B=-10.6% (95% CI -14.3- -6.8)] and spent larger proportions of time standing [B=9.5% (95% CI 6.4-12.6)] and walking [B=1.2% (95% CI 0.1-2.2)] than non-shift workers. However, these differences in occupational PA became smaller when the number of night shifts during accelerometer wear-time increased. Conclusions Leisure-time PA levels of hospital shift workers were similar to those of non-shift workers, but shift workers were less sedentary and more physically active (ie, standing/walking) at work. Future research to the role of occupational activities in the health effects of shift work is recommended.

BackgroundShift work has been related to adverse health outcomes that can partially be attributed to physical inactivity. However, our knowledge of the influence of shift work on physical activity and sedentary behavior is inconclusive. Therefore, this study aimed to assess physical activity levels among shift and non-shift workers among a sample of Iranian adults.MethodsBaseline data of the Ravansar Non-Communicable Disease (RaNCD) cohort study were used. All participants of RaNCD except those excluded due to unemployment or considerable disability were included in the study. We evaluated participants’ physical activity levels using the PERSIAN cohort questionnaire and examined its associations with being a shift worker.ResultsA total of 4695 participants with a mean age of 46.1 (SD = 7.74) were included in the study. In total, 1108 (23.6%) participants were shift workers, 1420 (30.2%) had insufficient physical activity levels, and 4283 (91.2%) were male. The prevalence of physical inactivity was significantly lower among shift workers compared to non-shift workers (21% vs. 33.1%, p < 0.001). Multiple backward stepwise binary logistic regression tests indicated that being a shift worker was significantly associated with a lower chance of having insufficient physical activity levels (OR = 0.77, 95% CI = 0.65–0.92, p = 0.003).ConclusionsThe prevalence of insufficient physical activity was higher among non-shift workers than shift workers in our study. By providing the factors associated with insufficient physical activity among the workers in a region of Iran, the current study findings might help policymakers target groups at higher risk of physical activity in Iran and design interventions to improve physical activity, especially among non-shift workers.

Blood pressure is a critical factor in the circulation system. There are two kinds of blood pressure abnormality known as hypertension or high blood pressure and low blood pressure or hypontension. Many risk factors to enhace it, or person who suffering hypertension, one of them shift work. A research about Malaysian male workers in a firm showed that the prevalence of shift work related to hypertension was significantly higher shift worker than non-shift worker. The result of Medical Check Up PT. X Gresik worker on 2017, that shift worker and non-shift have hypertension risk approxiametly 15.75 % or 26 workers. The purpose of this research, knowing the factors related to blood pressure on shift worker or non-shift worker in PT. X Gresik. This research cross-sectinal designed with 44 workers into 2 grohups and its selected to use purposive sampling. Data taken by through measurement and questionnaire. The data analysis are univariate analysis with cross tabulation and bivariate analysis with statistic test, its chisquared test and spearmen correlation. The result explained that shift worker and non-shift worker who have normal blood pressure 34.1 %, pre hypertension, 52.2%, and hypertension stage one 13.6%. In this research, significantly statistic of the history of family disease and body massa index are correlated to blood pressure (p 0.05). Based on research, it would be suggest to a company provide routine health service, and workers to check routinely blood pressure tension, to set diet with balanced nutrition. Keywords : Blood pressure, Shift and non-shift workers, PT. X Gresik

Introduction: Shift work is associated with increased incidence of obesity and other features of the metabolic syndrome. Health problems in shift workers are caused by several factors, one of these factors is the stress hormone cortisol. Aim of the work: to assess the association between night shift work and the changes in body mass index (BMI), fasting blood glucose, lipid (total cholesterol, HDL, and triglycerides) levels, cortisol hormone secretion, uric acid blood level and salivary cortisol level. Materials & Methods: this study was conducted on 160 male security personnel, their age ranging from 35 to 40 years in Cairo . Regarding the work schedule 80 subjects worked daytime for 8 hours, whereas 80 individuals worked only night shift for 12 hour with one day off, for at least continuous 5 years. Results: the results showed no significant difference between night shift and day workers as regard age and working years. As regard body mass index (BMI) there was highly significant difference (<0.001) between night and day workers. There was no significant difference between night and day shift workers as regard total cholesterol level, triglycerides, and fasting blood glucose (P< 0.05) where as there is a significant difference between night and day shift workers as regard HDL –cholesterol (P<0.05) and a highly significant difference between night and day shift workers as regard uric acid blood level (P<0.001).A significant difference was detected in salivary cortisol levels among night shift workers where the salivary cortisol level is higher in the evening than in the morning, also there is a significant difference in salivary cortisol level among day shift workers where the salivary cortisol level is higher in the morning than in the evening (P<0.05). Conclusion: Our results suggest an association between long-term shift work and increased body mass index, elevation cortisol level, HDL–cholesterol, fasting blood glucose and uric acid level. Further studies are needed to understand the biological mechanisms involved and the complex behavioral and social adaptations experienced by night-shift workers. Regular screening health programs should be done to maintain the health of shift workers.

Sleep disturbances and depressive symptoms of shift workers: Effects of shift schedules

Endothelial dysfunction and alterations in heart rate variability (HRV) as well as sleep deprivation and shift work have been associated with cardiovascular disease. The aim of this study was to compare HRV and endothelial function among shift and matched non-shift workers in response to total sleep deprivation and recovery sleep under identical laboratory settings. Eleven experienced male shift workers (shift work ≥ 5 years) and 14 non-shift workers were matched for age, body mass index, and cholesterol. HRV parameters [eg, HR variance and low frequency/high frequency (LF/HF) ratio] were derived from 5-minute electrocardiogram bins at 0.25, 4.25, 11.5, 12.5, and 13.5 hours after habitual wake-up time and endothelial function was assessed by flow-mediated dilatation (FMD) using ultrasound at 0.75 and 10.75 hours after habitual wake-up time, following baseline sleep, total sleep deprivation, and recovery sleep (posture- and food-controlled throughout). Circadian phase was assessed before baseline sleep by salivary dim light melatonin onset. There was no difference in circadian phase between shift and non-shift workers. HR variance was highest at 0.25 hours following total sleep deprivation and lowest after recovery sleep. A significantly higher LF/HF ratio, significantly lower HR variance, and a trend for a lower %FMD (P=0.08) were observed among shift compared to non-shift workers. Despite similar demographics, circadian phase, posture and food intake, differences in endothelial function and HRV were observed in the two groups, which may reflect higher sympathetic and/or lower parasympathetic activity, contributing to increased cardiovascular risk among the shift workers.

Purpose: This study was conducted to investigate and analyze the association between stress from shift and non-shift work as well as the effects living habits have on eating habits in order to identify why and how workers can improve their health and form proper eating habits for higher working efficiency. Methods: The subjects of this study were 361 workers from K manufacturing company from April 7 to 11, 2014 and they were surveyed using a questionnaire. The subjects were divided into two groups according to working pattern: shift workers (n = 216) and non-shift workers (n = 110). Results: In the general characteristics, there were significant differences in age, work career, work time, marriage, monthly income, and education levels between the two groups. For healthy behaviors, significant differences in subjective health status, moderate physical activity, drinking, smoking, and sleep time were observed between shift workers and non-shift workers. For eating habits, scores of non-shift workers having a regular mealtime, balanced meal composition, and vegetable and seaweed intakes were significantly higher than those of shift workers. The sum score of dietary habits in non-shift workers was also significantly lower than that in shift workers (p < 0.05). Total job stress score did not significantly differ between the two groups. Conclusion: The sum of eating habit scores according to work types was 16.1 ± 0.6 in non-shift workers and 14.0 ± 0.3 in shift workers. These results suggest that it is necessary to provide food suitable to characteristics of different workers according to work type which should be provided along with daily nutrition counseling to help subjects recognize their status.

ABSTRACTHigher depressive symptoms have been reported in rotating shift workers compared with day workers. Depressive symptoms in adults who do not engage in night work have also been shown to be associated with chronotype and sleep duration. This study examines associations between depressive symptoms, morningness-eveningness (i.e. the degree to which people prefer to be active in the morning or the evening), sleep duration and rotating shift work. Japanese nurses (1252 day workers and 1780 rotating shift workers, aged 20–59) were studied using a self-administered questionnaire. The questionnaire covered depressive symptoms, morningness-eveningness, sleep habits and demographic characteristics of the participants. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to determine the levels of depressive symptoms. A Japanese version of the Morningness-Eveningness Questionnaire (MEQ) was used to measure morningness-eveningness. The CES-D score of shift workers was significantly (p < 0.05) higher than that of day workers. The MEQ score was significantly (p < 0.05) lower (i.e. greater eveningness) in shift workers than in day workers. Sleep duration on the day shift was significantly (p < 0.05) shorter in shift workers than in day workers. Simple linear regression revealed that the MEQ score, sleep duration on the day shift and current work shift (i.e. rotating shift work) were significantly (p < 0.05) associated with the CES-D score. Multivariate linear regression indicated that greater eveningness and shorter sleep duration were independently associated with higher CES-D scores, while rotating shift work was not. These associations between the MEQ score, the sleep duration and the CES-D score were also confirmed in both day workers and shift workers when the groups were analyzed separately. These results suggest that greater eveningness and shorter sleep duration on the day shift were independently associated with higher levels of depressive symptoms, which may explain associations between rotating shift workers and depressive symptoms. These findings have important implications for the development of novel strategies for preventing poor mental health in day workers and rotating shift workers.

Recently, there has been interest in whether shift work may enhance susceptibility to infection. Our aim was to determine whether shift workers in the health-care field have a higher incidence, duration, and/or severity of influenza-like illness (ILI) and acute respiratory infection (ARI) than non–shift workers. From September 2016 to June 2017, 501 rotating and/or night-shift workers and 88 non–shift workers from the Klokwerk+ Study (the Netherlands, 2016–2017) registered the occurrence of ILI/ARI symptoms daily using a smartphone application. The incidence rate of ILI/ARI (defined as ≥2 symptoms on the same day/≥1 symptom on 2 consecutive days), the mean duration of each episode, and the incidence rate of severe episodes were compared between shift workers and non–shift workers using negative binomial regression and linear mixed-model analysis. In total, participants completed 110,347 diaries. Shift workers’ incidence rate of ILI/ARI was 1.20 (95% confidence interval (CI): 1.01, 1.43) times higher than that of non–shift workers, and for severe ILI/ARI episodes, shift workers’ incidence rate was 1.22 (95% CI: 1.01, 1.49) times higher. The mean duration of an ILI/ARI episode did not differ (ratio between means = 1.02, 95% CI: 0.87, 1.19). In conclusion, shift workers in health care had more ILI/ARI episodes and more severe ILI/ARI episodes than non–shift workers, but with a similar duration. Insight into underlying mechanisms connecting shift work and infection susceptibility will contribute to the design of preventive initiatives.

ObjectiveShift work has been implicated in cardiovascular disease (CVD), a major cause of death globally. The aim of this study was to evaluate the risk of developing CVD in shift work.DesignA cross-sectional study involving secondary analysis of shift and non-shift work from an industry in Ghana.ParticipantsTwo hundred (113 shift and 87 non-shift) consecutive workers who consented were recruited into the study. A structured questionnaire was administered to deduce information on participant’s age, alcohol consumption pattern, smoking habits, history of diabetes, stroke and hypertension.ResultsShift workers were found to be associated with higher body mass index (26.9 ± 4.6 vs 25.2 ± 3.3, p = 0.013); fasting blood glucose (5.9 ± 1.8 vs 5.3 ± 0.8, p ≤ 0.0001); glycated haemoglobin (4.9 ± 0.9 vs 4.2 ± 0.8, p ≤ 0.0001); high sensitivity C-reactive protein (2.5 ± 1.1 vs 1.8 ± 1.1, p < 0.0001); total cholesterol (5.9 ± 1.3 vs 5.2 ± 1.7, p = 0.002); triglycerides (1.3 ± 0.8 vs 1.1 ± 0.6, p = 0.015) and LDL cholesterol (3.6 ± 0.9 vs 3.2 ± 1.3, p = 0.04) than controls. Shift work however, had no associations with HDL-cholesterol.ConclusionIt can be concluded that shift work is associated with risk factors of CVD.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1750-3) contains supplementary material, which is available to authorized users.

Associations of eating duration and shift work with accelerated biological aging among U.S. workers

Prediction of suicidal ideation in shift workers compared to non-shift workers using machine learning techniques

Night shift work can associate with an increased risk for depression. As night workers experience a ‘misalignment’ between their circadian system and daily sleep–wake behaviors, with negative health consequences, we investigated whether exposure to circadian misalignment underpins mood vulnerability in simulated shift work. We performed randomized within-subject crossover laboratory studies in non-shift workers and shift workers. Simulated night shifts were used to induce a misalignment between the endogenous circadian pacemaker and sleep/wake cycles (circadian misalignment), while environmental conditions and food intake were controlled. Circadian misalignment adversely impacted emotional state, such that mood and well-being levels were significantly decreased throughout 4 days of continuous exposure to circadian misalignment in non-shift workers, as compared to when they were under circadian alignment (interaction of “circadian alignment condition” vs. “day”, mood: p < 0.001; well-being: p < 0.001; adjusted p-values). Similarly, in shift workers, mood and well-being levels were significantly reduced throughout days of misalignment, as compared to circadian alignment (interaction of “circadian alignment condition” vs. “day”, mood: p = 0.002; well-being: p = 0.002; adjusted p-values). Our findings indicate that circadian misalignment is an important biological component for mood vulnerability, and that individuals who engage in shift work are susceptible to its deleterious mood effects.