My Healthy Heart Blogs
Stress at Work Linked to Heart Disease
01/23/08
Living Well
Stress may affect more than psychological health. A new study has better identified the link between work stress and coronary heart disease.
The relationship between work stress and the onset of heart disease has been better defined by new research.
The study, published in the European Heart Journal, was the first large-scale study to look how work stress affects cardiovascular mechanisms. In the study, researchers found that stress could lead to coronary heart disease directly by activating stress pathways controlled by the interaction between the nervous system, the endocrine glands and their hormones, and indirectly by its association with unhealthy lifestyles.
“Stress at work is associated with an increased risk of coronary heart disease but the mechanisms underlying this association have remained unclear until now,” said Dr. Tarani Chandola, first author of the study.
Chandola and other researchers gathered information on the incidence of coronary heart disease, death from coronary heart disease, non-fatal heart attack, chest pain, heart rate variability, increases in the levels of cortisol (the stress hormone), metabolic syndrome, and behavioral risk factors like diet, exercise, smoking, and drinking.
During more than a decade of follow-up, researchers found that chronic work stress was associated with coronary heart disease. Interestingly, the association was stronger among men and women younger than 50. Their risk of coronary heart disease was 68 percent higher than people without work-related stress.
The most important finding was the evidence linking work stress with the biological mechanisms that cause coronary heart disease. The autonomic nervous system (ANS) is the part of the nervous system that regulates involuntary actions, such as the action of the heart, and it has a central role in the stress responses. The signals that are sent to the heart that tell it how to work and control the variability of the heart rate, are mediated by the ANS. Workers who suffered from greater stress were more likely to have lowered heart rate variability and poor vagal tone. They also found that the hypothalamic-pituitary-adrenal axis (HPA) – a major part of the neuroendocrine system – was disturbed by greater stress, and this was shown by the fact that stressed workers had higher than normal morning levels of cortisol.
Adjusting for lifestyle behaviors did not change the association between stress and the chance of developing heart disease. Moreover, higher levels of stress are also associated with less-healthy lifestyles. For example, people reporting high levels of work stress did not eat as many fruits and vegetables and exercised less.
