Modelling and association of stress related biomarkers and Socioeconomic Status over the working life-course

  • José Cuitún Coronado

Student thesis: Phd

Abstract

This thesis empirically assesses the associations between socioeconomic status, acute and chronic stressors and stress related biomarkers during the working life-course for men and women living in England aged over 50 years. Specifically, this thesis seeks to understand the extent to which, acute and chronic stressors over the working life-course, help to explain socioeconomic differences in stress related biomarkers among older adults. To rigorously undertake this research, the basis of the thesis is comprised by three empirical papers: 1. Socioeconomic status and Perceived stress differences in diurnal cortisol: Longitudinal evidence from the Whitehall II Study. 2. Are socioeconomic differences in diurnal cortisol profiles underestimated by missing values? Compensating for Missing Data in the Whitehall II Study. 3. Allostatic Load and Effort-Reward Imbalance: Associations over the Working-Career. The contribution of this thesis to the research literature is unique in its treatment and modelling of the determinants of stress related biomarkers. Firstly, I explored the role that acute stress (perceived stress) and chronic stress (socioeconomic status) have in explaining the levels of stress (cortisol) throughout the day. I found that there were socioeconomic differences in diurnal cortisol profiles, which persisted even after controlling for perceived stress. However, perceived stress did not help to explain why the poorest civil servants had flatter diurnal cortisol slopes. Secondly, due to the amount of missing data, I analysed if missing data could lead to an underestimation of the socioeconomic differences in the diurnal cortisol slope. Using multiple imputation, and I found that imputed estimates of cortisol tended to be a bit higher at awakening for the middle and high socioeconomic groups, while the estimates for the low-grade jobs group diverged at bedtime, showing a flatter diurnal slope for the multiple imputation estimates. This suggests that the presence of missing data could lead to an underestimation in socioeconomic differences in biomarker of the stress response. Thirdly, using allostatic load, I explored if work stress (measured by effort-reward imbalance) over the working career predicts higher levels of allostatic load. Repeated exposure to effort-reward imbalance towards the end of the working career predicted higher levels of allostatic load, with employees working in semi-routine and routine jobs reporting more accumulated effort-reward imbalance. We now have a better understanding of the association between socioeconomic status and biomarker of the stress response. Through the analysis of acute (perceived stress) and chronic stressors, the former may not be as important in understanding socioeconomic differences in stress compared to chronic stressors like work related stressors over the working life-course.
Date of Award1 Aug 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorNicholas Shryane (Supervisor) & Tarani Chandola (Supervisor)

Keywords

  • Multiple imputation
  • Life-course
  • Work stress
  • Effort-reward imbalance
  • Allostatic load
  • Missing data
  • Perceived stress
  • Diurnal cortisol slope
  • Socioeconomic status
  • Biomarkers
  • Stress

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