








key: cord-334543-gavnscor
authors: Lim, Rachel K.; Wambier, Carlos G.; Goren, Andy
title: Are night shift workers at an increased risk for COVID-19?
date: 2020-07-29
journal: Med Hypotheses
DOI: 10.1016/j.mehy.2020.110147
sha: 
doc_id: 334543
cord_uid: gavnscor

Recent data has revealed an association between coronavirus disease-19 (COVID-19) incidence and seasonally regulated androgen sensitivity. This potential relationship between SARS-CoV-2 infection and clock genes, coupled with previously reported effects of night shift work on health leads us to hypothesize that night shift workers may be at an increased physiological risk of coronavirus disease-19 (COVID-19). Shift work, especially night shift work, has long been associated with several chronic health conditions. The mechanisms that drive these associations are not well understood; however, current literature suggests that the disruption of circadian rhythms may cause downstream hormonal and immune effects that render night shift workers more susceptible to disease. First, circadian rhythms may play a role in the mechanism of viral infection, as viral vaccines administered in the morning elicit greater immune responses than those administered in the afternoon. Next, increased exposure to light at night may inhibit melatonin production, which has been observed to enhance DNA repair and shown to upregulate expression of Bmal1, an established as an inhibitor of herpes simplex virus and influenza. Finally, abnormal immune cell and cytokine levels have been observed following night-shift work. These data suggest that further research is warranted and that high-risk occupations should be considered as public health policies are introduced and evolve.

(COVID- 19) incidence and seasonally regulated androgen sensitivity. This potential relationship between SARS-CoV-2 infection and clock genes, coupled with previously reported effects of night shift work on health leads us to hypothesize that night shift workers may be at an increased physiological risk of coronavirus disease-19 (COVID- 19) .

Shift work, especially night shift work, has long been associated with several chronic health conditions. The mechanisms that drive these associations are not well understood; however, current literature suggests that the disruption of circadian rhythms may cause downstream hormonal and immune effects that render night shift workers more susceptible to disease. First, circadian rhythms may play a role in the mechanism of viral infection, as viral vaccines administered in the morning elicit greater immune responses than those administered in the afternoon. Next, increased exposure to light at night may inhibit melatonin production, which has been observed to enhance DNA repair and shown to upregulate expression of Bmal1, an established as an inhibitor of herpes simplex virus and influenza. Finally, abnormal immune cell and cytokine levels have been observed following night-shift work. These data suggest that further research is warranted and that high-risk occupations should be considered as public health policies are introduced and evolve. Although many occupations have transitioned to remote settings during the pandemic, certain "essential" workers such as health care workers, food industry workers, and police officers have continued to work in-person. It would be interesting to test this hypothesis through a large-scale survey of essential shift workers who have continued to work night shifts as the COVID-19 pandemic began and progressed.

Comparing the incidence of COVID-19 infections among night shift and day-shift workers will shed light upon this topic.

PERSPECTIVES AND CONCLUSIONS: 7 In conclusion, because several viral infections, including influenza, are closely linked to circadian rhythms, and night shift workers regularly disrupt their circadian rhythms, it is likely that night shift workers are at a greater risk of COVID-19 infection and further research is warranted.

A Novel Coronavirus from Patients with Pneumonia in China

A four year seasonal survey of the relationship between outdoor climate and epidemiology of viral respiratory tract infections in a temperate climate

Androgenetic Alopecia Present in the Majority of Hospitalized COVID-19 Patients -the "Gabrin sign

What does androgenetic alopecia have to do with COVID-19? An insight into a potential new therapy

Clock genes may drive seasonal variation in SARS-CoV-2 infectivity: Are we due for a second wave of COVID-19 in the fall?

Genetics of Circadian Rhythms

Health consequences of shift work and insufficient sleep

Night Shift Work and Risk of Breast Cancer

Night-Shift Work and Risk of Prostate Cancer: Results From a Canadian Case-Control Study, the Prostate Cancer and Environment Study

Metabolic syndrome in shift healthcare workers

Rotating night shift work and adherence to unhealthy lifestyle in predicting risk of type 2 diabetes: results from two large US cohorts of female nurses

Is shift work associated with a higher risk of overweight or obesity? A systematic review of observational studies with metaanalysis

The effects of nocturnal life on endocrine circadian patterns in healthy adults

Interplay between circadian clock and viral infection

Preliminary evidence that morning vaccination is associated with an enhanced antibody response in men

Morning vaccination enhances antibody response over afternoon vaccination: A cluster-randomised trial

Cell autonomous regulation of herpes and influenza virus infection by the circadian clock

Genome-wide effect of pulmonary airway epithelial cell-specific Bmal1 deletion

Epidemiology of urinary melatonin in women and its relation to other hormones and night work

Melatonin for the prevention and treatment of cancer

A Versatile Protector against Oxidative DNA Damage

Simulated Night Shift Disrupts Circadian Rhythms of Immune Functions in Humans

Conflicts of interest: The authors do not have any conflicts of interest to report

None 9

The authors do not have any conflicts of interest to report. 10 

