Workplace Stress and Heart Disease

In a 12-year population study of over 10,000 London-based civil servants, Tarani Chandola, D.Phil., senior lecturer in the department of epidemiology and public health at University College London and his colleagues, examined the effects of work stress on heart disease in people ages 35 to 55. At the start of the study in 1985 and then again in 1989, participants were asked to complete the job strain questionnaire, a standard measure of psychological stress involving questions on decision making power, support from colleagues and overall work demands. To determine how the autonomic nervous system (ANS), which regulates your organs and hormones, responds to a prolonged state of stress, researchers checked levels of cortisol, a stress hormone, and assessed heart rate variability, a measure of heart health.

 

In this study, people who suffered from ongoing work stress had higher than normal morning levels of cortisol, which remained elevated throughout the day. Also, those who reported greater work stress were more likely to have a lowered heart rate variability, indicating strain on the heart. During the 12 years of follow up, researchers found that the individuals who experienced prolonged work stress had a 68% higher risk of coronary artery disease compared with those who reported no stress at work or retired during the course of the study. Finally, 32% of the effect of work stress on heart disease was attributed to metabolic syndrome, unhealthy habits such as over eating, smoking, or a couch potato lifestyle.

 

“What’s unique about this study is how we were able to demonstrate that chronic stress is linked to heart attack indirectly through unhealthy habits, and also directly through its effect on your cortisol levels and heart rate functioning,” said Dr. Chandola. “We found that chronically stressed out people had lower heart rate variability and higher levels of circulating cortisol in the bloodstream, which damages the heart and blood vessels and weakens normal body functions like tissue repair.”



Reference

  1. Chandola T. et al. Work Stress and Coronary Heart Disease: What are the mechanisms? European Heart Journal, January 2008