Associations of life course socioeconomic position and job stress with carotid intima-media thickness. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Abstract

RationaleThe association between life course socioeconomic position (SEP) and subclinical atherosclerosis is not consistent across studies. Socioeconomic adversities early in life are related to an increased probability of a low occupational grade and more stressful jobs in adulthood. However, the role of job stress in explaining the life course social gradient in subclinical atherosclerosis is unknown. ObjectivesTo examine whether life course SEP is associated with carotid intima-media thickness (IMT) and to investigate whether this association is partially mediated by job stress. MethodsThis study used baseline data (2008–2010) for 8806 current workers from ELSA–Brasil. Maternal education, social class of first occupation and social class of current occupation were used to evaluate childhood, youth and adulthood SEP, respectively. Accumulation of risk across the life course was also evaluated. Job stress was assessed by the Swedish Demand–Control–Support Questionnaire. Directed acyclic graph and linear regression models were used. ResultsLow childhood SEP was associated with increased IMT only in women, but low youth and adulthood SEP were associated with higher IMT in both genders. The simultaneous adjustment for all SEP indicators showed that only adulthood SEP continued to be associated with IMT. However, higher IMT values were observed among men and women sequentially exposed to low SEP in more than one period of life. High-strain jobs and low job control were not associated with IMT independent of SEP. ConclusionOur results support a model of the cumulative effects of exposures to SEP across the life span because the highest IMT values were observed in individuals sequentially exposed to low SEP in more than one period of life. We did not find that job stress explained the association between life course SEP and IMT, suggesting that strategies to address socioeconomic inequalities in CVD should target additional steps beyond reducing job stress.