Sex and gender differences in the associations between psychosocial stressors at work and coronary heart disease incidence: an 18-year longitudinal study of 5192 Canadian workers

Background Psychosocial stressors at work (PSW) are modifiable occupational stressors associated with an increased coronary heart disease (CHD) incidence. While systematic reviews suggest differences between women and men, there has been limited examinations of potential effect modifiers. This study aimed to explore the effect modifications of characteristics related to sex (biological) and gender (sociocultural) in the associations between PSW and CHD incidence over an 18-year follow-up. Methods This study relied on a prospective cohort of 5192 white-collar workers (50 % women) from 19 public and semi-public enterprises in Quebec, Canada. PSW, defined according to the job strain and effort-reward imbalance (ERI) models, were assessed using self-administered, validated questionnaires. Incident CHD cases were identified from medico-administrative databases using validated algorithms. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for the associations between PSW and CHD incidence, stratified by sex, and characteristics related to sex (age) and gender (education level, occupational position, and children load). Results Associations between PSW and CHD incidence differed by sex. In men, being exposed to both job strain and ERI was associated with a 2-fold increased CHD risk (HR: 2.01, 95 % CI: 1.52–2.65), rising to a 2.80-fold risk among those aged 60 and older (HR: 2.80, 95 % CI: 1.90–4.13). Amplified associations were also observed in men with lower education (HR: 3.23, 95 % CI: 1.73–6.03) and a low children load (HR: 2.48, 95 % CI: 1.74–3.54). In women, the association between ERI and CHD was stronger, although it remained marginally non-significant, among those under 60 years-old (HR: 1.57, 95 % CI: 0.96–2.57), with a lower education level (HR: 1.84, 95 % CI: 0.95–3.56) and with an intermediate to high children load (HR: 1.72, 95 % CI: 0.96–3.10). Conclusions This study reinforces the importance of considering sex- and gender-related characteristics — such as age, education, and caregiving responsibilities — when examining the associations between PSW and CHD incidence. However, the findings observed among women require replication in larger prospective cohorts.