Impact of Night Shift Work on Circadian Rhythm and Performance of Workers

This article discusses the impact of night shift work on circadian rhythm and performance of workers. It explores the concept of circadian rhythm, the effects of night shift work on sleep patterns and health, and the positive influence of light on the circadian rhythm of night-shift workers.

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Management
2/13/2019

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Contents
Introduction................................................................................................................................2
Circadian Rhythm......................................................................................................................2
Impact of night Shift work on Circadian rhythm and Performance of workers.........................4
Positive influence of the light on the circadian rhythm of the night-shift workers....................5
Conclusion..................................................................................................................................7
References..................................................................................................................................8

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Introduction
The report brings about the discussion on the aspect of night shift workers, circadian rhythm,
and the resulting performance within their workplace. The report will analyse these issues or
concepts through the perspective of the multiple authors and their studies leading to the
findings of the research.
Circadian Rhythm
Circadian rhythm is the term defined as physical, mental, and behavioural changes that occur
in the daily life activities of an individual. These provide responses to the light and darkness
in the environment of an organism. For an instance, a light-related circadian rhythm may
include the issue or aspect of sleeping during the night and getting up during the day.
Circadian rhythms influences a number of aspect related to an individual such as the cycles of
sleep-wake, release of hormones, or secretion, eating behaviour, temperature of the body. In
this respect, the biological clocks, which operate at a high, speed or generate slow results in
disrupted circadian rhythm; therefore, related to an individual’s health, sleep patterns, and
other functions of the human body (Agostinelli et al., 2016).
According to some studies, and data on the issue of night shift work and circadian rhythm, it
has been analysed that metabolic, physiological, and behavioural processes play an important
role or exhibit 24-hour rhythms in most of the organisms, including humans. In this concept,
a self-sustained clock and the environmental cues such as light-dark cycles, and the intake of
food drive these rhythms. The author in their study has revealed about the concept of
disturbed circadian rhythms which are known to be closely related to some disorders, and
sleeping disorder is found common amongst them (McKenna, Reiss and Martin, 2017).
The sleep disorders, includes the aspects of advanced sleep, and delayed sleep type phase
along with the non-entrained disorders affecting circadian rhythm sleep disorders, i.e. called
as CRSDs. The aspect of non-entrained type of sleep characterises the timing of sleep, which
occurs with a 30 minute to 1-hour delay on the daily basis. Another issue associated with the
sleep disorders in context to circadian rhythm is the shift work. The same issue will be
described in detail, in the later part of the section, along with the impact on the performance
of people (Lin et al., 2015).

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The researchers Morris et al. (2016) throughout their study analysed through the literature
review about the misalignment and the relationship with the problems causing, depressive
symptoms in the delayed sleep phase, or any other cardiovascular health diseases.
For analysing the association between these two things, the study conducted on around 182
DSPD students, who fall under the age group of 16-64 years. These were the individuals who
were engaged either, in employment or they were the school students. After the screening and
other tests of monitoring, observed that some students did not show the relation or association
between the DSPD and the misalignment of circadian rhythm.
Furthermore, the research carried out on the assessment of the sleep disorders, it has found
that there are certain factors, which lead to misalignment of the human circadian rhythm, and
these include aspects such as (Roenneberg and Merrow, 2016):
 Disrupted body clock
 Inappropriate timed sleep and wake
 Dysregulation of the feeding behaviour
 Changes in the appetite leading to stimulation of hormones and,
 Glucose metabolism and mood
In addition, there are some of the extrinsic and intrinsic factors, which lead to misalignment
of the human circadian rhythm. Shift work has been attributed as the extrinsic factors where,
the health illness or disorders associated with circadian rhythm are included in intrinsic
factors (Cuesta, Boudreau and Boivin, 2017).
Impact of night Shift work on Circadian rhythm and Performance of workers
From the above section, it has understood that there are various factors, which lead to the
circadian misalignment, and one of them is the shift work. Night shift work has found as one
major issue affecting the circadian rhythm, and leads to degradation in the performance of the
workers. A general idea in context to the negative impacts on their performance may consist
of increased alertness, and high prevalence to the errors and mistakes at workplace.
In simple terms, it refers to the individuals who are required to sleep at times except, during
night and staying up and working all night affects their cycle. The impact on the cycle occurs

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due to the reason that an individual changes their natural body functions, which further leads
to the disruption of circadian rhythm.
Daily circadian misalignment impairs human cognitive performance task-
dependently
The authors Chellappa, Morris and Scheer (2018), were of the view that daily circadian
misalignment leads to the impairment of the human cognitive performance dependent on the
nature of task to be done. Moreover, it has been already analysed in the preceding part of the
report, that one of the major issue is sleep disorders, which are associated with the circadian
rhythm. The occurrence of sleeping disorders is highly affected by the shift timings of the
workers; therefore, increased shift work enhances the risk for human error, such as
drowsiness due to the shift work (Reynolds et al., 2017).
It has been analysed that working overnight or night shift workers, found to be experiencing
the issue of cognitive vulnerabilities beyond the aspect of differences in work conditions.
Overnight work or operations have considered the issue as it challenges the circadian rhythm,
which is observed to be supporting the aspect of daytime vigilance of the workers and
nocturnal sleep. Thus, this creates the issue of misalignment between internal circadian
rhythms, and the society requirements for gaining desired sleep or effective wake times
(Chang et al., 2015).
On the other hand, it has been analysed that the shift work, which disrupts circadian rhythms,
treated as major human issues. In addition, there has been a link between the shift working
and increases incidence of breast cancers and other health issues. To explain this, in an
effective manner it has been observed that exposure-to-light, which is a common factor for
night-shift workers can lead to the reduced secretion of melatonin, and cause breast cancer
(Potter et al., 2016).
Impact of the light on the night shift workers has found in terms of high risks of tumours and
the metastatic cancers because of the low levels of melatonin. Thus, it has observed through
the research that the effect of low or dim light has been high on the night shift workers, and
caused a negative impact on their performance and productivity. However, several studies
have revealed the difference in the effect of light during night on the workers on the grounds
of ethnic and race backgrounds. Studies stated the fact in consideration to the Asian and
Asian American women, working as night shift working in the night shifts, has reported the

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lack of melatonin as compared to the white woman. It reveals the fact that there has been a
high impact of the light at night on the health of women workers. Moreover, these issues are
observed in the work or occupations such as nursing, or health professionals, and airline
candidates. These studies were carried out by conduct of the surveys on around 15 young
female nurses in the healthcare of Australia, who were consecutively working in night shifts
were exposed to the issue of bright light led to the decreased proficiency in their profession.
Thus, these are some of the evidences, which provide relevant knowledge and information
representing the effect of light on the night shift workers (Figueiro et al., 2016).
Positive influence of the light on the circadian rhythm of the night-shift workers
Night work, light exposure, and melatonin on workdays and days off
Light has been considered crucial in leading to the positive impact on the circadian rhythms
of the night shift workers. The authors Daugaard et al (2017), through their research has
stated well that the exposure to light tend to affect our biological clock and may lead to delay
and advance of the sleep and awake patterns. Thereupon, it leads to two different situations or
impact on the person’s biological clock and the performance. An advance means the situation
when the person will wake up earlier than the following days, whereas the delay caused due
to light exposure due to sleeping will make the person wake up later in the following days.
Therefore, if the person or workers during their night shift are provided enough or bright light
will help in enhancing their commitment and productivity in the work (Buss, Wirth and
Burch, 2018).
Thus, it can be stated that the proper alignment between light, the circadian clock, and the
output behavioural patterns produces a temporal order, which is essential for the survival
within environment. Now, there will be an analysis or assessment of the impact of the light,
i.e. positive impacts leading to high performance or improved productivity of the night shift
workers within organisations (Fernandez et al., 2018).
Prevention of fatigue and insomnia in shift workers—a review of non-
pharmacological measure
According to Richter et al (2016), it has found that individuals who were working under the
exposure of the bright light therapy become effective and capable enough to control or alter

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their clock or circadian rhythm. This was a benefit to them for enhancement of their
performance during the night shift. In addition, it also helps to continue the interaction with
the peers, and other superiors in the workplace. The study under this research carried out with
around the sample size of 3504 people, which included individuals from different fields or
occupations. These consist of the workers in the industries or factories, office employees,
aircraft maintenance engineers, and the non-shift workers, along with the people or
employees working in simulated shifts. Thus, another batch of several 26 workers were also
analysed for the aspect of assessing the issue of the insomnia due to the unhealthy working
conditions (James et al., 2017).
Moreover, it has been analysed that the light therapy, sunglasses, and strict schedules of sleep
helped the night shift workers in the adjustment or creation of a compromised circadian phase
position. This adjustment leads to an increased level of the performance and high alertness
especially, during night shifts while still managing enough time for sleep on off days.
Light induces productivity and alertness of workers during night shift, and leads to their high
performance and attainment of their goals in the longer period. The authors in their study
have revealed that melatonin is supressed by the indoor (light), and this was the reason that
the high levels of melatonin were found in the workers in the night shifts. However, the light
therapy or the exposure to light has been considered to counteract this suppression, and often
leads to effective circadian adjustment or adaptation (Touitou, Reinberg and Touitou, 2017).
Inability to the adjustment to the shift work may result in extortion or fatigue, which results
in undesirable impacts and loss of efficiency, concentration difficulties, and reduced
productivity. Thus, it has been analysed that the factor or element of bright light is essential
for the health and wellbeing of workers, in order to attain high work performance (Laposky et
al., 2016).
The researchers have conducted study in several other hospitals, which has led to an analysis
stating that utilising the ‘bright light exposure therapy’ has increased the productivity and
performance. The study conducted using the sample size of 36 nurses, in the hospitals who
were not exposed to bright light, faced issues regarding their health, and reduced levels of
performance (Van Maanen et al., 2016). Therefore, it was taken as one of the major issue
which was further resolved through the treatment provided to the nurses regarding their
health issues. Therefore, work in the rotating shifts has been one major issue in the

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productivity and performance of the female workers especially nurses in the hospitals. The
report has described well through the aspect of literature review on the night shift work,
highlighting the positive effect of light on the workers, and their productivity and
performance. Thus, the use of bright light exposure therapy has represented as one major
aspect establishing relationship between the shift work and adaptation to the circadian
rhythm. The feature or benefit of the bright light therapy has linked to some other benefits
also, such as reduced depression, and improvement in the cognitive behavioural techniques
(Van Maanen et al., 2016).
Conclusion
To conclude the above discussion it has been analysed that the concept of the circadian
rhythm and the night shift work has been common in the modern organisations. The aspect of
night shift work has represented some issues such as excessive fatigue and insomnia,
absenteeism and reduced work performance.

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References
Agostinelli, F., Ceglia, N., Shahbaba, B., Sassone-Corsi, P. and Baldi, P. (2016) What time is
it? Deep learning approaches for circadian rhythms. Bioinformatics, 32(12), pp.8-17.
Buss, M.R., Wirth, M.D. and Burch, J.B. (2018) Association of shiftwork and leukocytes
among national health and nutrition examination survey respondents. Chronobiology
international, 35(3), pp. 435-439.
Chang, A.M., Aeschbach, D., Duffy, J.F. and Czeisler, C.A. (2015) Evening use of light-
emitting eReaders negatively affects sleep, circadian timing, and next-morning
alertness. Proceedings of the National Academy of Sciences, 112(4), pp. 1232-1237.
Chellappa, S.L., Morris, C.J. and Scheer, F.A. (2018) Daily circadian misalignment impairs
human cognitive performance task-dependently. Scientific reports, 8(1), p.3041.
Cuesta, M., Boudreau, P. and Boivin, D.B. (2017) Basic circadian timing and sleep-wake
regulation. In Sleep Disorders Medicine (pp. 79-102). New York: Springer.
Daugaard, S., Garde, A.H., Bonde, J.P.E., Christoffersen, J., Hansen, Ä.M., Markvart, J.,
Schlünssen, V., Skene, D.J., Vistisen, H.T. and Kolstad, H.A. (2017) Night work, light
exposure and melatonin on work days and days off. Chronobiology international, 34(7), pp.
942-955.
Fernandez, D.C., Fogerson, P.M., Ospri, L.L., Thomsen, M.B., Layne, R.M., Severin, D.,
Zhan, J., Singer, J.H., Kirkwood, A., Zhao, H. and Berson, D.M. (2018) Light affects mood
and learning through distinct retina-brain pathways. Cell, 175(1), pp.71-84.
Figueiro, M.G., Sahin, L., Wood, B. and Plitnick, B. (2016) Light at night and measures of
alertness and performance: implications for shift workers. Biological research for
nursing, 18(1), pp. 90-100.
James, S.M., Honn, K.A., Gaddameedhi, S. and Van Dongen, H.P. (2017) Shift work:
Disrupted circadian rhythms and sleep—implications for health and well-being. Current
sleep medicine reports, 3(2), pp.104-112.
Laposky, A.D., Van Cauter, E. and Diez-Roux, A.V. (2016) Reducing health disparities: the
role of sleep deficiency and sleep disorders. Sleep medicine, 18, pp. 3-6.

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Lin, X., Chen, W., Wei, F., Ying, M., Wei, W. and Xie, X. (2015) Night-shift work increases
morbidity of breast cancer and all-cause mortality: a meta-analysis of 16 prospective cohort
studies. Sleep medicine, 16(11), pp.1381-1387.
McKenna, H.T., Reiss, I.K. and Martin, D.S. (2017) The significance of circadian rhythms
and dysrhythmias in critical illness. Journal of the Intensive Care Society, 18(2), pp.121-129.
Morris, C.J., Purvis, T.E., Hu, K. and Scheer, F.A. (2016) Circadian misalignment increases
cardiovascular disease risk factors in humans. Proceedings of the National Academy of
Sciences, 113(10), pp. 1402-1411.
Potter, G.D., Skene, D.J., Arendt, J., Cade, J.E., Grant, P.J. and Hardie, L.J. (2016) Circadian
rhythm and sleep disruption: causes, metabolic consequences, and
countermeasures. Endocrine reviews, 37(6), pp.584-608.
Reynolds, A.C., Paterson, J.L., Ferguson, S.A., Stanley, D., Wright Jr, K.P. and Dawson, D.
(2017) The shift work and health research agenda: considering changes in gut microbiota as a
pathway linking shift work sleep loss and circadian misalignment, and metabolic
disease. Sleep medicine reviews, 34, pp.3-9.
Richter, K., Acker, J., Adam, S. and Niklewski, G. (2016) Prevention of fatigue and insomnia
in shift workers—a review of non-pharmacological measures. EPMA journal, 7(1), p. 16.
Roenneberg, T. and Merrow, M. (2016) The circadian clock and human health. Current
biology, 26(10), pp. 432-443.
Touitou, Y., Reinberg, A. and Touitou, D. (2017) Association between light at night,
melatonin secretion, sleep deprivation, and the internal clock: Health impacts and
mechanisms of circadian disruption. Life sciences, 173, pp.94-106.
Van Maanen, A., Meijer, A.M., van der Heijden, K.B. and Oort, F.J. (2016) The effects of
light therapy on sleep problems: a systematic review and meta-analysis. Sleep medicine
reviews, 29, pp.52-62.