Aims: To assess the associations of onset of workplace conflict on incident cardiovascular disease (CVD) and changes in biomarkers.

Methods: The study included 2704 employees aged 18–65 years and free of workplace conflict at baseline (T₀), from the Swedish Work, Lipids, Fibrinogen study (proportion of women: 17 %). Exposure to onset of workplace conflict was ascertained at T₁ using self-reports (mean interval between T₀ and T₁: 5 years). Participants were linked to nationwide registers to ascertain incident CVD. Changes in biomarkers, including body mass index, waist-hip ratio, high-density lipoprotein cholesterol, triglycerides, glucose and fibrinogen, were measured and calculated between T₀ and T₁. Cox regressions and linear regressions were applied for analyses on conflicts in relation to CVD and conflicts in relation to changes in biomarkers, respectively. Age, sex, educational level, marital status, pre-existing comorbidities, employment contract, and shift work were adjusted for in the main analyses.

Results: About 10 % experienced onset of workplace conflict between T₀ and T₁. Among 2682 participants who were free from CVD at T₀, 87 CVD events were recorded (mean follow-up from T₁: 7.8 years, incidence rate: 41.5/10,000 person-year). Onset of workplace conflict at T₁ was associated with 2.42 times (95 %CI 1.42, 4.12) higher risk of developing CVD during the follow-up period. Among 877 participants with information on changes in fibrinogen, onset of workplace conflict at T₁ was associated with fibrinogen increase from T₀ to T₁ (mean difference=0.14; 95 %CI 0.02, 0.25) and onset of high fibrinogen (OR=1.41; 95 %CI 1.04,1.90). These associations were largely robust for additional adjustments, restrictions and consideration of selection bias and were not likely to be affected by reverse causation.

Conclusions: Onset of workplace conflict was related to higher risks of developing CVD and fibrinogen increase.