Time of exposure to night work and carotid atherosclerosis: a structural equation modeling approach using baseline data from ELSA-Brasil

  • Aline Silva-Costa
  • Joanna Guimarães
  • Dora Chor
  • Maria de Jesus Mendes da Fonseca
  • Isabela Bensenor
  • Itamar Santos
  • Sandhi Barreto
  • Rosane Härter Griep
Original Article



The study of cardiovascular diseases (CVD) associated with night work is difficult due to the long period required for conditions to manifest and the healthy-worker effect. Analyzing asymptomatic pre-clinical changes in the atherosclerotic process is a way to assess the pathways between exposure to night work and CVD.


To evaluate the associations between night work and subclinical atherosclerosis measured by carotid intima-media thickness (CIMT) using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).


We conducted cross-sectional analyses using baseline data (2008–2010) from 9785 civil servants, aged 35–74 years. The associations between time of exposure to night work and mean CIMT were examined using a structural equation model.


The sample included 4259 men and 5526 women, mean age of 51.6 years. A total of 1778 (18.2%) individuals were exposed to night work (594 current and 1184 former night workers), and the mean years of night work exposed was 11.47 (SD = 9.45) years. On average, mean CIMT was 0.606 (SD = 0.130) mm. Among men, the increase in exposure to night work was significantly associated with an increase in BMI and CIMT. Among women, night work was not associated with increased CIMT. In relation to the indirect associations, results suggest a possible mediation by BMI, diabetes and hypertension on the association between the years of night work and mean CIMT only among men.


Night work was associated with increased CIMT only among men. These findings add to the knowledge of the possible pathways that link night work and carotid atherosclerosis. Additionally, these results contribute to the recognition of work schedules as a public health problem that should be addressed by the medical community and policy makers.


Carotid intima-media thickness Atherosclerosis Work schedule Night shift work 



The ELSA-Brasil baseline was supported by the Brazilian Ministry of Health (Science and Technology Department) and the Brazilian Ministry of Science and Technology (Financiadora de Estudos e Projetos and CNPq National Research Council) [Grants 01 06 0010.00 RS, 0106 0212.00 BA, 01 06 0300.00 ES, 01 06 0278.00 MG, 01 06 0115.00 SP, 01 06 0071.00 RJ]. ASC was the recipient of scholarships from CNPq-Brasil (150551/2015-0).

Compliance with ethical standards

Conflict of interest

All authors declare that they do not have any competing interests.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Aline Silva-Costa
    • 1
  • Joanna Guimarães
    • 2
  • Dora Chor
    • 2
  • Maria de Jesus Mendes da Fonseca
    • 2
  • Isabela Bensenor
    • 3
  • Itamar Santos
    • 3
  • Sandhi Barreto
    • 4
  • Rosane Härter Griep
    • 5
  1. 1.Department of Collective HealthFederal University of Triângulo Mineiro (UFTM)UberabaBrazil
  2. 2.Sergio Arouca National School of Public HealthOswaldo Cruz Foundation (FIOCRUZ)Rio de JaneiroBrazil
  3. 3.Center for Clinical and Epidemiological ResearchUniversity of São Paulo (USP)São PauloBrazil
  4. 4.Department of Preventive and Social MedicineFederal University de Minas Gerais (UFMG)Belo HorizonteBrazil
  5. 5.Laboratory of Health and Environmental EducationOswaldo Foundation (FIOCRUZ)Rio de JaneiroBrazil

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