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Shift Work: Disrupted Circadian Rhythms and Sleep - Implications for Health and Well-Being

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Purpose of review: Our 24/7 society is dependent on shift work, despite mounting evidence for negative health outcomes from sleep displacement due to shift work. This paper reviews short- and long-term health consequences of sleep displacement and circadian misalignment due to shift work. Recent findings: We focus on four broad health domains: metabolic health; risk of cancer; cardiovascular health; and mental health. Circadian misalignment affects these domains by inducing sleep deficiency, sympathovagal and hormonal imbalance, inflammation, impaired glucose metabolism, and dysregulated cell cycles. This leads to a range of medical conditions, including obesity, metabolic syndrome, type II diabetes, gastrointestinal dysfunction, compromised immune function, cardiovascular disease, excessive sleepiness, mood and social disorders, and increased cancer risk. Summary: Interactions of biological disturbances with behavioral and societal factors shape the effects of shift work on health and well-being. Research is needed to better understand the underlying mechanisms and drive the development of countermeasures. The final publication is available at link.springer.com
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CIRCADIAN RHYTHM DISORDERS (F TUREK, SECTION EDITOR)
Shift Work: Disrupted Circadian Rhythms
and SleepImplications for Health and Well-being
Stephen M. James
1,2
&Kimberly A. Honn
1,2
&Shobhan Gaddameedhi
1,3
&
Hans P.A. Van Dongen
1,2
Published online: 27 April 2017
#Springer International Publishing AG 2017
Abstract
Purpose of Review Our 24/7 society is dependent on shift
work, despite mounting evidence for negative health out-
comes from sleep displacement due to shift work. This paper
reviews short- and long-term health consequences of sleep
displacement and circadian misalignment due to shift work.
Recent Findings We focus on four broad health domains: met-
abolic health, risk of cancer, cardiovascular health, and mental
health. Circadian misalignment affects these domains by in-
ducing sleep deficiency, sympathovagal and hormonal imbal-
ance, inflammation, impaired glucose metabolism, and dys-
regulated cell cycles. This leads to a range of medical condi-
tions, including obesity, metabolic syndrome, typeII diabetes,
gastrointestinal dysfunction, compromised immune function,
cardiovascular disease, excessive sleepiness, mood and social
disorders, and increased cancer risk.
Summary Interactions of biological disturbances with behav-
ioral and societal factors shape the effects of shift work on
health and well-being. Research is needed to better understand
the underlying mechanisms and drive the development of
countermeasures.
Keywords Circadian misalignment .Sleep displacement .
Metabolic health .Cancer risk .Heart health .Mental health
Introduction
It has long been recognized that shift work has a negative
impact on health and well-being. Historically, this has been
attributed to adverse effects of long work hours, nighttime
light exposure, and psychosocial factorseffects that are still
recognized as relevant for tolerance to shift work [1,2].
However, the health consequences of shift work should first
be understood in terms of a fundamental misalignment be-
tween the circadian (i.e., near-24-h) rhythmof the endogenous
biological clock and the timing of the sleep/wake cycle [3].
While this paper is concerned primarily with the long-term
health consequences of shift work, the implications of circa-
dian misalignment between the biological clock and the sleep/
wake cycle are perhaps best illustrated by how such misalign-
ment increases the risk of workplace accidents and injuries.
In healthy, non-shift workers with normal sleep patterns,
daytime wakefulness is driven by the biological clock, which
produces circadian rhythmicity driving increased alertness
during the daytime and decreased alertness during the night-
time [4,5]. This circadian process is counteracted by a ho-
meostatic pressure for sleep, which builds across waking
hours [6,7]. When working during daytime hours, these two
processes function in concert and in synchrony with the envi-
ronmental light/dark cycle to maintain alertness while awake
and at work, while allowing for consolidated sleep during the
night. Working nights or early morning shifts means that an
individual must be awake when the circadian drive for alert-
ness is low and asleep when it is high, in opposition to the
natural biological rhythm. This leads to shortened and
disrupted sleep and excessive sleepiness while awake [8,9].
This article is part of the Topical Collection on Circadian Rhythm
Disorders
*Hans P.A. Van Dongen
hvd@wsu.edu
1
Sleep and Performance Research Center, Washington State
University, Spokane, WA, USA
2
Elson S. Floyd College of Medicine, Washington State University,
Spokane, WA, USA
3
College of Pharmacy, Washington State University, Spokane, WA,
USA
Curr Sleep Medicine Rep (2017) 3:104112
DOI 10.1007/s40675-017-0071-6
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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... Work ergonomics and health education of employers and employees regarding potential health hazards at work with excessive night shifts are still underestimated and requiring attention in areas of health care institutions. Proper medical care is also important for maintaining the health of the employee [11]. ...
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