A new study has found a link between being bullied at work or experiencing violence at work and a higher risk of heart attacks and stroke.

“If there is a causal link between bullying or violence at work and cardiovascular disease, then the removal of workplace bullying would mean we could avoid 5 percent of all cardiovascular cases, and the eradication of violence at work would avoid more than 3 percent of all cases,” said Tianwei Xu, a Ph.D. student at the University of Copenhagen in Denmark, who led the study.

For the study, researchers analyzed data from 79,201 working men and women in Denmark and Sweden, between the ages of 18 and 65, who had no history of cardiovascular disease (CVD). The men and women were participants in three studies that started between 1995 and 2011 and have been followed ever since, the researchers reported.

When they joined the studies, the participants were asked about bullying and violence in the workplace and how frequently they experienced each of them. Information on the number of cases of heart and brain blood vessel disease and deaths was obtained from nationwide registries, the researchers explained.

The researchers also took into account other factors that could affect whether the participants were affected by CVD, such as body mass index, alcohol consumption, smoking, mental disorders, other pre-existing health conditions, shift work, and occupation.

According to the study’s findings, 9 percent of participants reported being bullied at work, while 13 percent reported experiencing violence or threats of violence at work in the past year.

After adjusting for age, sex, country of birth, marital status, and level of education, the researchers found that those who were bullied at work had a 59 percent higher risk of CVD, while those who experienced violence (or threats of violence) had a 25 percent higher risk.

The more bullying or violence that was encountered, the greater the risk of CVD, the researchers discovered.

Compared with people who did not suffer bullying, people who reported being bullied frequently — the equivalent to being bullied almost every day — in the past 12 months had 120 percent higher risk of CVD. People who were exposed most frequently to workplace violence had a 36 percent higher risk of cerebrovascular disease, such as stroke, than those not exposed to violence, but there did not appear to be a corresponding increase in heart disease, according to the study’s findings.

The researchers discovered that bullying in the workplace occurred mostly from colleagues (79 percent) rather than from people outside the organization (21 percent), while violence or threats of violence at work originated mainly from people outside the organization (91 percent), than from within (9 percent).

This, combined with the fact that those exposed most frequently to workplace violence were not more likely to suffer from heart disease, suggests that workers may have received training about how to deal with violence they encounter as part of their jobs and may be better equipped to deal with it and avoid long-term consequences, the researchers said.

“Workplace bullying and workplace violence are distinct social stressors at work,” Xu said. “Only 10 to 14 percent of those exposed to at least one type of exposure were suffering from the other at the same time. These stressful events are related to a higher risk of cardiovascular disease in a dose-response manner — in other words, the greater the exposure to the bullying or violence, the greater the risk of cardiovascular disease.”

She adds that the researchers cannot conclude from this study that this is a “causal relation between workplace bullying or workplace violence and cardiovascular disease.”

“But we provide empirical evidence in support of such a causal relation, especially given the plausible biological pathway between workplace major stressors and cardiovascular disease,” she said. “This is further supported by the dose-response trend and the robustness of the results in various sensitivity analyses. Experimental studies on violence and bullying would be highly unethical and our study thus provides the best evidence of this association.”

She added that the effect of bullying and violence on the incidence of cardiovascular disease in the general population is comparable to other risk factors, such as diabetes and drinking alcohol. This “further highlights the importance of workplace bullying and workplace violence in relation to cardiovascular disease prevention,” she said.

The study was published in The European Heart Journal.

Source: European Society of Cardiology