Introduction
Experts have long puzzled over the fact that many victims of heart attacks do not have risk factors such as high blood pressure and high cholesterol. Arguments have thus been made about the important role played by not only physiological but also behavioral factors. In the last three decades, a group of scientists has championed the idea that the way people think, feel and deal with the daily stresses of life can have a significant effect on their cardiovascular health. Nevertheless, the impact of stress on heart diseases is highly controversial among scientists.
Support for the association between stress and heart disease
Various studies have been conducted to support the hypothesis that stress is highly associated with heart disease. One of the best tools developed for measuring stress level is the self-rating Social Readjustment Scale, which was developed by Dr. Holmes and Dr. Rahe of the University of Washington in the mid-1960s (Kuper, Marmot & Hemingway, 2002). These researchers interviewed thousands of patients, after which they compiled a list of 43 life events that were generally perceived as stressful and ordered them according to the level of stress. Events such as the death of a spouse were top on the list, with stress points as high as 100.
Other events that received considerable stress points included routine events such as opening schools, as well as positive events such as outstanding achievements. The researchers argued that the important thing was how much life change the event required. The researchers followed their patients over a long period of time and concluded that the accumulation of 150 or more stress points in a given year was significantly associated with the risk of major illnesses such as heart attack in a span of two years.
This is probably because of the amount of life change the events necessitated and the ensuing persistent activation of the fight-or-flight response. The researchers recommended anticipating life changes and planning for them in advance so as to avoid the significant accumulation of stress points in a short duration of time (Kuper et al., 2002).
In addition to unexpected life events, work-related stress has also been examined as a cause of heart disease. It is argued that the increasing demands placed on employees are contributing to a rise in an epidemic of work stress, which adversely affects employees’ psychological; and physical health. However, the question of whether it is legitimate to claim that work characteristics can affect the body the same way that a virus or physical injury does is controversial (Kuper et al., 2002). The epidemiological model of disease causation asserts that the effects of pathogens on physical health are mainly independent of subjective factors.
This model has been extended by social epidemiologists to take into consideration social causes of ill health, but the social factors are regarded as objective pathogens which affect the human body regardless of the meaning attached to them by the subject. This is the case with the discourse of work stress, whereby stress-related personal injury is viewed as an unmediated impact of objective conditions.
The discourse of work-related factors on heart disease and other physical health problems has also been supported by Karasek and Theorell (1990), whose model predicts that employees who consistently deal with heavy, intense, and monotonous workload are at an increased risk of health problems such as heart illnesses and psychiatric disorders. Despite the wide support given to the association between stress and heart diseases, a number of scientists oppose the existence of such an association.
Arguments against the association between stress and heart disease
Arguments against the association between stress and heart disease usually revolve around the subjective nature of the data used to assess the association. In the case of the effect of work-related stress on physical health, for instance, it has been argued that such studies rely on individuals’ subjective assessment of their work characteristics as well as their mental health status. Therefore, instead of the work-related stress factors causing psychiatric and physical illnesses, it could be that mental health problems drive the individuals to have a negative evaluation of their work and physical health problems.
The studies include the Framingham Heart Study (Haynes, Feinleib & Kannel, 1980), which was based on a sample of 1822 individuals. This study did not find any significant association between perceived daily stress score and coronary heart disease. In a different study, Rosengren, Orth-Gomer, Wedel, and Wilhelmsen (1993) showed prospectively that middle-aged men with high levels of self-perceived psychological stress have up to 50 percent higher incidence rate of coronary artery disease after controlling for all established risk factors. Another study by Hollis, Connett, Stevens, and Greenlick (1990) found that the relative risk (after adjusting for a number of risk factors) of angina pectoris related to each life event was 1.08, but there was no statistically significant evidence of an association between life events and fatal or non-fatal myocardial infarction.
Macleod et al. (2002), in their study of Scottish men, reported that the association between stress and heart diseases (angina in their case) was most likely as a result of the tendency of the patients who reported higher levels of stress to also report more symptoms than their counterparts. They did not find a corresponding association with the objective measures of heart diseases, which led them to conclude that the positive association between stress and heart disease found in prior literature could be spurious.
The problem with the epidemiological model of work stress is that it does not take into account the role of consciousness in mediating the relationship between stress and heart diseases or other illnesses (Macleod et al., 2002). The model assumes that high job demands and low job control and intrinsically pathogenic at a purely biological level, just like the way tobacco smoke is carcinogenic, for instance. It may be that a heavy workload leads to physical fatigue, which may directly and largely affect the body unconsciously.
Nevertheless, the job strain variables are not fundamentally concerned with fatigue but with psychological stress, anxiety and depression. These events may present themselves as physical symptoms and therefore are measured as physiological changes, but importantly they also contain an aspect of perception, cognition, and reflection.
Conclusion
The debate surrounding the association between stress and heart diseases continues as more studies come up. Those supporting the association between the two variables argue that stress emanating from significant life changes is highly associated with heart diseases, especially if the affected parties do not adopt effective coping strategies. On the other hand, those opposing the association between stress and heart disease argue that much of the evidence is based on subjective rather than objective data, which leads to bias in the results. All in all, the association between risk and heart disease is mixed, and no conclusive findings have so far been found.
Reference List
Haynes, S., Feinleib, M., & Kannel, W. (1980). The relationship of psychosocial factors to coronary heart disease in the Framingham Study. III. Eight-year incidence of coronary heart disease. American Journal of Epidemiology, 111, 37-58.
Hollis, J., Connett, J., Stevens, V., & Greenlick, M. (1990). Stressful life events, type A behavior, and the prediction of cardiovascular and total mortality over six years. Journal of Behavioral Medicine, 13, 263-280.
Karasek, R., & Theorell, T. (1990). Healthy work: stress, productivity, and the reconstruction of working life. New York, NY: Basic Books.
Kuper, H., Marmot, M., & Hemingway, H. (2002). Systematic review of prospective cohort studies of psychosocial factors in the etiology and prognosis of coronary heart disease. Seminal Vascular Med, 2, 267–314.
Macleod, J., Smith, G., Heslop, P., Metcalfe, C., Carroll, D., & Hart, C. (2002). Psychological stress and cardiovascular disease: empirical demonstration of bias in a prospective observational study of Scottish men. British Medical Journal, 324, 1247-1256.
Rosengren, A., Orth-Gomer, K., Wedel, H., & Wilhelmsen, L. (1993). Stressful life events, social support, and mortality in men born in 1933. British Medical Journal, 307, 1102-1105.