Abstract
Background
Shift work is a risk factor for many diseases, including cardiovascular disease. Although
the biological pathways are still unclear, it is hypothesized that cortisol disruption
during night work is an intermediate. The objective of this study is to determine
whether total cortisol production and cortisol pattern mediate the relationship between
current shift work and cardiometabolic risk (CMR) among female hospital employees.
Methods
A cross-sectional study was conducted among 326 female employees (166 rotating shift
workers, 160 day workers), recruited from a hospital in Southeastern Ontario, Canada,
during 2011 to 2014. Participants completed a baseline interview, questionnaire, and
clinical exam. Urine samples were collected over two 24-hour periods and used to analyze
creatinine-adjusted cortisol, which was then used to calculate total cortisol production
(AUCG), and pattern (AUCI). Mediation analysis was performed to test the mediating effect of cortisol in the
relationship between shift work and a continuous CMR score.
Results
Current shift work is associated with a 0.52 higher CMR score (95% CI: 0.15, 0.89),
a lower cortisol output (AUCG), and a flatter pattern (AUCI) over a 2-day period. AUCG is a partial mediator in the relationship between shift work and CMR, whereas AUCI is not. AUCG is also associated with CMR while controlling for shift work, suggesting that lower
total cortisol production is also linked to CMR in non-shift workers.
Conclusions
Total cortisol production is a partial mediator in the relationship between rotating
shift work and CMR among female hospital employees, whereas cortisol pattern is not
a mediator.
Résumé
Contexte
Le travail par roulement est un facteur de risque de nombreuses maladies, y compris
les maladies cardiovasculaires. Bien que les mécanismes biologiques en cause ne soient
pas encore élucidés, une hypothèse voudrait que la perturbation du métabolisme du
cortisol pendant le travail de nuit soit un mécanisme intermédiaire. L’objectif de
cette étude est de déterminer si la production de cortisol total et le profil du cortisol
assurent la médiation du lien entre le travail par roulement en cours et le risque
cardiométabolique (RCM) chez des femmes travaillant dans un hôpital.
Méthodologie
Une étude transversale a été menée auprès de 326 employées (166 employées ayant un
travail en rotation et 160 employées de jour) recrutées dans un hôpital du sud-est
de l’Ontario (Canada) entre 2011 et 2014. Les participantes ont passé une entrevue
initiale, elles ont répondu à un questionnaire et passé un examen clinique. Des échantillons
d’urine ont été recueillis pendant deux périodes de 24 heures aux fins d’analyse des
taux de cortisol corrigés selon la créatinine; ces taux ont ensuite servi à calculer
la production de cortisol total (ASCG) et le profil du cortisol (ASCI). Une analyse a été réalisée pour tester l’effet médiateur du cortisol dans le contexte
du lien existant entre le travail par roulement et un score de RCM continu.
Résultats
Le travail par roulement en cours est associé à un score de RCM plus élevé de 0,52
(intervalle de confiance [IC] à 95 %: 0,15 à 0,89), à une élimination inférieure du
cortisol (ASCG) et à un profil plus plat (ASCI) du cortisol sur une période de deux jours. L’ASCG est un médiateur partiel du lien entre le travail par roulement et le RCM, ce qui
n’est pas le cas de l’ASCI. L’ASCG est également associée au RCM lorsqu’une correction est apportée en fonction du travail
par roulement, ce qui indique que la production inférieure de cortisol total est également
liée au RCM chez les personnes n’ayant pas un travail par roulement.
Conclusion
Contrairement au cycle du cortisol, la production de cortisol total est un médiateur
partiel du lien existant entre le travail en rotation et le RCM chez les employées
de l’hôpital de l’étude.
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Article info
Publication history
Published online: February 09, 2018
Accepted:
February 6,
2018
Received:
November 14,
2017
Footnotes
See page 688 for disclosure information.
Identification
Copyright
© 2018 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
