Bullying or Violence on the Job May Boost CVD Risk

Being bullied or exposed to violence or the threat of violence in the workplace can take a toll in terms of cardiovascular health, a Scandinavian study suggests.

In pooled results from three population-based studies, the risk of developing CVD during follow-up was heightened both in people who said they had been bullied at work (HR 1.59; 95% CI 1.28-1.98) and in those who said they had been exposed to violence (HR 1.25; 95% CI 1.12-1.40), researchers led by Tianwei Xu, a PhD student at the University of Copenhagen, Denmark, report in a study published online November 19, 2018, ahead of print in the European Heart Journal.

“More research needs to be done to investigate the effective prevention measures for workplace bullying and violence,” Xu told TCTMD in an email. “Also, research needs to be done to understand the potential mechanism of CVD development after being exposed to workplace bullying and violence. By understanding the mechanism, people can be introduced, for example, to a better coping strategy or a better workplace coping resource to reduce their future disease risk.

“This is of great importance,” she continued, “as workplace violence, for example, might be difficult to be completely eliminated due to the nature of some occupations.”

The idea that exposure to violence can harm the heart recently took center stage—literally—at the American Heart Association 2018 Scientific Sessions, where researchers highlighted direct and indirect ways that various types of violence have been associated with poorer cardiovascular health.

Prior research has shown that bullying and violence in the workplace are associated with the development of type 2 diabetes, Xu noted. “And with a plausible mechanistic pathway to the development of cardiovascular disease through behavioral (passive coping-related), emotional, and physiological reactions after being exposed, we think it is very likely that bullying and violence at work also contribute to the development of CVD.”

To explore the issue, the investigators looked at data from three population-based studies in Sweden and Denmark. The analysis included 79,201 working men and women ages 18 to 65 (mean age 43 years; 53% women) who were free from CVD at baseline. Exposure to workplace bullying or violence was self-reported at baseline, and incident CVD events during follow-up were identified using national registries.

Overall, 9% of participants said they had been bullied at work during the past year, mostly by colleagues, supervisors, or subordinates. Exposure to violence or the threat of violence, mostly stemming from clients and not coworkers, was reported by 13%. There was little overlap between the two groups.

Mean follow-up was 3.8 years for the analysis of bullying and 12.4 years for the analysis of violence. Both exposures were related to incident CVD in a dose-response fashion after adjustment for various confounders, with consistent associations for both coronary and cerebrovascular disease.

The researchers estimated that 5.0% and 3.1% of cases of CVD could have been avoided if workplace bullying and violence, respectively, were eliminated. Those population attributable risks are similar to those seen with some standard cardiovascular risk factors like diabetes (4.0%) and “risky drinking” (3.0% to 6.0%).

Mechanisms Unknown

The observational nature of the study makes it impossible to establish causality, and there are numerous potential mechanisms to explain the observed relationships.

For one, exposure to bullying or violence may lead to negative emotions, depression, or anxiety, which in turn could trigger coping mechanisms—such as overeating or excessive alcohol use—that increase the risk of CVD.

“It has been hypothesized that these coping-oriented behaviors and negative emotions increase CVD risk, along with various stress-related physiological reactions, including elevated blood pressure, increased heart rate, and systemic inflammation level,” Xu et al explain. “They can also result in reduced insulin sensitivity, increased platelet aggregation, and hypercoagulability, endothelial dysfunction, and arrhythmias.”

Further research is needed, but “we think elevated blood pressure might be a very important mechanism for the association between workplace bullying and incident CVD,” Xu noted.

‘Cautious Interpretation’ Needed

In an accompanying editorial, Christoph Herrmann-Lingen, MD (University of Göttingen Medical Center, Germany), says the study requires “cautious interpretation and independent replication.”

He raises questions about how exposure to bullying and violence were measured, how adverse experiences might relate to disease outcomes up to 12 years later, and how participants’ preexisting psychological state might have contributed to the workplace problems they encountered.

“We therefore do not know to what degree the increased CVD incidence was driven by objective events (that could best be prevented by workplace interventions), subjective perceptions of the events, and psychobiological reactions to them (which might require efforts addressing individual stress resilience and coping) or preexisting psychological conditions (which are per se associated with increased CVD risk and would call for early recognition, treatment, or even prevention of the underlying problems),” Herrmann-Lingen argues.

Though “workplace bullying or violence are two factors that might need more attention in future CVD prevention programs,” he concludes, “future observational studies and intervention trials should elaborate on their relative relevance in the broader context of psychosocial CVD risk factors.”