scholarly journals Environmental circadian disruption suppresses rhythms in kidney function and accelerates excretion of renal injury markers in urine of male hypertensive rats

2020 ◽  
Author(s):  
Atlantis M Hill ◽  
G. Ryan Crislip ◽  
Adam Stowie ◽  
Ivory Ellis ◽  
Anne Ramsey ◽  
...  
Keyword(s):  
Shift Work ◽  
Kidney Injury ◽  
Circadian Disruption ◽  
Light Cycle ◽  
Work Schedules ◽  
Shift Workers ◽  
Spontaneously Hypertensive ◽  
Genetic Manipulations ◽  
Adverse Health Outcomes ◽  
Traditional Work

Non-traditional work schedules, such as shift work, have been associated with numerous health issues including cardiovascular and metabolic disease. These work schedules can chronically misalign environmental timing cues with internal circadian clock systems in the brain and in peripheral organs, leading to dysfunction of those systems and their associated biological processes. Environmental circadian disruption in the kidney may be an important factor in the increased incidence of hypertension and adverse health outcomes in human shift workers. The relationship between renal rhythmicity and injury resilience is not well understood, especially in the context of environmental, rather than genetic manipulations of the circadian system. We conducted a longitudinal study to determine whether chronic shifting of the light cycle that mimics shift work schedules would disrupt output rhythms of the kidney and accelerate kidney injury in salt-loaded male spontaneously hypertensive, stroke-prone rats. We observed that chronic shifting of the light-dark (LD) cycle misaligned and decreased the amplitude of urinary volume rhythms as the kidney phase-shifted to match each new lighting cycle. This schedule also accelerated glomerular and tubular injury marker excretion, as quantified by nephrin and KIM-1 compared with rats kept in a static LD cycle. These data suggest that disrupted rhythms in the kidney may decrease resilience and contribute to disease development in systems dependent on renal and cardiovascular functions.

Circadian Activity Rhythms and Sleep in Nurses Working Fixed 8-hr Shifts

2014 ◽  
Vol 17 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Jiunn-Horng Kang ◽  
Nae-Fang Miao ◽  
Ing-Jy Tseng ◽  
Trevor Sithole ◽  
Min-Huey Chung
Keyword(s):  
Shift Work ◽  
Night Shift ◽  
Circadian Activity ◽  
Subjective Sleep Quality ◽  
Shift Workers ◽  
Activity Rhythms ◽  
Time Frequency ◽  
Subjective Sleep ◽  
Adverse Health Outcomes ◽  
Evening Shift

Shift work is associated with adverse health outcomes. The aim of this study was to explore the effects of shift work on circadian activity rhythms (CARs) and objective and subjective sleep quality in nurses. Female day-shift ( n = 16), evening-shift ( n = 6), and night-shift ( n = 13) nurses wore a wrist actigraph to monitor the activity. We used cosinor analysis and time–frequency analysis to study CARs. Night-shift nurses exhibited the lowest values of circadian rhythm amplitude, acrophase, autocorrelation, and mean of the circadian relative power (CRP), whereas evening-shift workers exhibited the greatest standard deviation of the CRP among the three shift groups. That is, night-shift nurses had less robust CARs and evening-shift nurses had greater variations in CARs compared with nurses who worked other shifts. Our results highlight the importance of assessing CARs to prevent the adverse effects of shift work on nurses’ health.

scholarly journals Impacts of shift work: A study in textile companies in Portugal

2017 ◽  
Vol 1 (1) ◽  
pp. 69-78
Author(s):  
I. S. Silva ◽  
J. Keating ◽  
D. Costa
Keyword(s):  
Shift Work ◽  
Social Life ◽  
Sleep Disturbances ◽  
Night Shift ◽  
The Other ◽  
Work Schedules ◽  
Textile Workers ◽  
Shift Workers ◽  
Work Shifts ◽  
Morning Shift

Shift work, especially if it involves night work and/or weekend work, may represent disadvantages for workers and their families at the level of family, social life, and health. The present study evaluates the impacts of three work shifts (morning, afternoon and night) on sleep, family and social life as well as satisfaction with work schedules. In total, 373 Portuguese textile workers participated in this study; all were men. The results indicated that night shift workers had greater sleep disturbances and less satisfaction with their work schedules. On the other hand, morning shift workers were most satisfied with family and social life in association with their work schedules. Based on the results, implications of the practice have been reflected.

scholarly journals Shift-work: is time of eating determining metabolic health? Evidence from animal models

2018 ◽  
Vol 77 (3) ◽  
pp. 199-215 ◽  
Author(s):  
Natalí N. Guerrero-Vargas ◽  
Estefania Espitia-Bautista ◽  
Ruud M. Buijs ◽  
Carolina Escobar
Keyword(s):  
Food Intake ◽  
Shift Work ◽  
Temporal Patterns ◽  
Experimental Models ◽  
Circadian Disruption ◽  
Metabolic Dysfunction ◽  
Light At Night ◽  
Shift Workers ◽  
Time Signals ◽  
Altered Metabolism

The circadian disruption in shift-workers is suggested to be a risk factor to develop overweight and metabolic dysfunction. The conflicting time signals given by shifted activity, shifted food intake and exposure to light at night occurring in the shift-worker are proposed to be the cause for the loss of internal synchrony and the consequent adverse effects on body weight and metabolism. Because food elicited signals have proven to be potent entraining signals for peripheral oscillations, here we review the findings from experimental models of shift-work and verify whether they provide evidence about the causal association between shifted feeding schedules, circadian disruption and altered metabolism. We found mainly four experimental models that mimic the conditions of shift-work: protocols of forced sleep deprivation, of forced activity during the normal rest phase, exposure to light at night and shifted food timing. A big variability in the intensity and duration of the protocols was observed, which led to a diversity of effects. A common result was the disruption of temporal patterns of activity; however, not all studies explored the temporal patterns of food intake. According to studies that evaluate time of food intake as an experimental model of shift-work and studies that evaluate shifted food consumption, time of food intake may be a determining factor for the loss of balance at the circadian and metabolic level.

Circadian principles and design of rotating shift work schedules

1986 ◽  
Vol 251 (3) ◽  
pp. R636-R638 ◽  
Author(s):  
F. W. Turek
Keyword(s):  
Circadian Rhythms ◽  
Shift Work ◽  
Sleep Time ◽  
New Work ◽  
Work Schedules ◽  
Work Schedule ◽  
Work Time ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

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

scholarly journals The effect of three shift systems as perceived by the partners of emergency services workers

2001 ◽  
Vol 27 (2) ◽  
Author(s):  
Marion Fourie ◽  
Delene Vsser
Keyword(s):  
Shift Work ◽  
Emergency Services ◽  
Work Schedules ◽  
Domestic Life ◽  
Shift Workers ◽  
The Social ◽  
The Family

This study is aimed at determining the effect of different shift systems on the social and domestic life of a sample of emergency services workers. The opinions of the partners of these workers were sought, because the influence of shift work should be viewed within the context of the family as its members are directly affected by the work schedules of shift workers. Opsomming Die doel van die ondersoek was om die effek van verskillende skofstelsels op die sosiale en huislike lewe van n steekproef van workers in die nooddienste te bepaal. Die menings van die gades van hierdie werkers is nagevors, want die uitwerking van skofwerkstelsels behoort in die konteks van die gesin gesien te word, aangesien gesinslede direk bemvloed word deur die skofskedules van die werker.

scholarly journals Shift work influences the outcomes of Chlamydia infection and pathogenesis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephanie R. Lundy ◽  
Shakyra Richardson ◽  
Anne Ramsey ◽  
Debra Ellerson ◽  
Yan Fengxia ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Shift Work ◽  
Chlamydial Infection ◽  
Severe Disease ◽  
Fertility Rate ◽  
Circadian Disruption ◽  
Chlamydia Infection ◽  
Control Group ◽  
Adverse Health Outcomes ◽  
Normal Light

AbstractShift work, performed by approximately 21 million Americans, is irregular or unusual work schedule hours occurring after 6:00 pm. Shift work has been shown to disrupt circadian rhythms and is associated with several adverse health outcomes and chronic diseases such as cancer, gastrointestinal and psychiatric diseases and disorders. It is unclear if shift work influences the complications associated with certain infectious agents, such as pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility resulting from genital chlamydial infection. We used an Environmental circadian disruption (ECD) model mimicking circadian disruption occurring during shift work, where mice had a 6-h advance in the normal light/dark cycle (LD) every week for a month. Control group mice were housed under normal 12/12 LD cycle. Our hypothesis was that compared to controls, mice that had their circadian rhythms disrupted in this ECD model will have a higher Chlamydia load, more pathology and decreased fertility rate following Chlamydia infection. Results showed that, compared to controls, mice that had their circadian rhythms disrupted (ECD) had higher Chlamydia loads, more tissue alterations or lesions, and lower fertility rate associated with chlamydial infection. Also, infected ECD mice elicited higher proinflammatory cytokines compared to mice under normal 12/12 LD cycle. These results imply that there might be an association between shift work and the increased likelihood of developing more severe disease from Chlamydia infection.

scholarly journals Environmental Circadian Disruption Increases Stroke Severity and Dysregulates Immune Response

2020 ◽  
Vol 35 (4) ◽  
pp. 368-376
Author(s):  
Anne M. Ramsey ◽  
Adam Stowie ◽  
Oscar Castanon-Cervantes ◽  
Alec J. Davidson
Keyword(s):  
Shift Work ◽  
Inflammatory Responses ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Circadian Disruption ◽  
Stroke Severity ◽  
Shift Workers ◽  
History Of ◽  
Cerebral Artery Occlusion ◽  
The Brain

Understanding the health consequences of chronic disruption of circadian rhythms can contribute to improving prevention strategies for shift workers. Chronic circadian disruption in shift work has been linked to a higher risk of stroke. Dysregulated immune responses are also linked to circadian disruption and may be a factor in stroke outcomes in shift workers. In this study, we test the hypotheses that specific schedules of circadian disruption exacerbate inflammatory responses in the brain, causing an increase in infarct size after experimentally induced ischemic stroke. Mice were exposed to 1 of 5 different lighting schedules followed by a 30-min middle cerebral artery occlusion, then reperfusion and 3-day recovery. A history of weekly phase advances resulted in an increased infarct volume versus the control lighting schedule. These effects were shift-direction specific, nonpermanent, and required multiple shifts to occur. In a separate cohort, stereotaxic injections of lipopolysaccharide were given bilaterally after exposure to 1 of 3 different lighting schedules. Ratios of pro- to anti-inflammatory cytokine expression show dysregulated responses after a history of phase advances. We conclude that chronic circadian disruption leads to worsened stroke outcome in a direction- and schedule-specific manner likely because of priming of the inflammatory response in the brain. These pieces of evidence suggest that the health impacts of shift work may be improved by targeting shift work scheduling, inflammatory mediators, or both.

scholarly journals The impact of different shift work schedules on the levels of anxiety and stress in workers in a petrochemicals company

2009 ◽  
Vol 26 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Katie Moraes de Almondes ◽  
John Fontenele Araújo
Keyword(s):  
Shift Work ◽  
Trait Anxiety ◽  
Work Conditions ◽  
Work Schedules ◽  
Test Results ◽  
State Trait Anxiety Inventory ◽  
Shift Workers ◽  
Stress Symptom ◽  
Informed Consent Form ◽  
The Impact

This study evaluated anxiety and stress in workers under different shift work conditions. The sample comprised 239 workers, with an average age of 42.6, standard deviation = 5.7 years, divided into fixed daytime working (n=52) and different working shifts (n=187). Documentation: Free and informed consent form; ID's; State-Trait Anxiety Inventory; Lipp's Stress Symptom Inventory for Adults. We used the t-test for independent samples, ANOVA, Pearson's correlation and the two-sample Comparison of proportions Test. Results showed that shift workers had higher State-Trait Anxiety scores than fixed daytime workers (t=-4.994; p=0.0001; t=-2.816; p=0.005, respectively). Both samples exhibited stress, but there were no statistically significant differences between the groups (t=-1.052; p=0.294). Shift work schedules caused more situational and dispositional anxiety, but did not significantly increase stress levels when compared to fixed daytime working.

scholarly journals Modeling the circadian regulation of the immune system: sexually dimorphic effects of shift work

2020 ◽  
Author(s):  
Stéphanie M.C. Abo ◽  
Anita T. Layton
Keyword(s):  
Mathematical Model ◽  
Immune System ◽  
Circadian Clock ◽  
Shift Work ◽  
Acute Inflammation ◽  
Clock Genes ◽  
Work Schedules ◽  
Shift Workers ◽  
Natural Sleep ◽  
Males And Females

AbstractThe circadian clock exerts significance influence on the immune system and disruption of circadian rhythms has been linked to inflammatory pathologies. shift workers often experience circadian misalignment as their irregular work schedules disrupt the natural sleep-wake cycle, which in turn can cause serious health problems associated with alterations in genetic expressions of clock genes. In particular, shift work is associated with impairment in immune function, and those alterations are sex-specific. The goal of this study is to better understand the mechanisms that explain the weakened immune system in shift workers. To achieve that goal, we have constructed a mathematical model of the mammalian pulmonary circadian clock coupled to an acute inflammation model. shift work was simulated by an 8h-phase advance of the circadian system with sex-specific modulation of clock genes. The model reproduces the clock gene expression in the lung and the immune response to various doses of lipopolysaccharide (LPS). Under normal conditions, our model predicts that a host is more sensitive to LPS at CT12 versus CT0 due to a change in the dynamics of IL-10. We identify REV-ERB as a key modulator of IL-10 activity throughout the circadian day. The model also predicts a reversal of the times of lowest and highest sensitivity to LPS, with males and females exhibiting an exaggerated response to LPS at circadian time (CT) 0, which is countered by a blunted immune response at CT12. Overall, females produce fewer pro-inflammatory cytokines than males, but the extent of sequelae experienced by males and females varies across the circadian day. This model can serve as an essential component in an integrative model that will yield mechanistic understanding of how shift work-mediated circadian disruptions affect the inflammatory and other physiological responses.Author summaryShift work has a negative impact on health and can lead to chronic diseases and illnesses. Under regular work schedules, rest is a night time activity and work a daytime activity. Shift work relies on irregular work schedules which disrupt the natural sleep-wake cycle. This can in turn disrupt our biological clock, called the circadian clock, a network of molecular interactions generating biochemical oscillations with a near 24-hour period. Clock genes regulate cytokines before and during infection and immune agents can also impact the clock function. We provide a mathematical model of the circadian clock in the lung coupled to an acute inflammation model to study how the disruptive effect of shift work manifests itself in males and females during inflammation. Our results show that the extent of sequelae experienced by male and female mice depends on the time of infection. The goal of this study is to provide a mechanistic insight of the dynamics involved in the interplay between these two systems.

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