Mechanisms Underlying Psychosocial Associations With Ischemic Heart Disease (Kuopio)

BACKGROUND:

Considerable interest and controversy exist concerning the role of psychosocial factors in the pathogenesis of ischemic heart disease. Studies of the prevalence, incidence, and mortality from ischemic heart disease have implicated socioeconomic status, job strain, Type A behavior, hostility, social support, and other variables.

The study used baseline data previously collected as part of the Kuopio Ischemic Heart Disease Risk Factor Study conducted in eastern Finland by the Research Institute of Public Health and the Research Institute of Exercise Medicine, both in Kuopio, and the Finnish National Public Health Institute in Helsinki. The area of eastern Finland lies within the area of greatest morbidity and mortality from ischemic heart disease in Finland, was part of the reference area for the evaluation of the North Karelia Project, and is part of the World Health Organization MONICA project.

DESIGN NARRATIVE:

The study was longitudinal in design. Physical examinations were conducted at baseline and information collected on behavioral risk factors, medical history, and medications. Evaluations included a maximal exercise tolerance test, four day supervised food recordings, a broad set of hematological and chemical tests from fasting venous blood and two 24-hour urine samples. Holter monitoring and ultrasonography of the carotid arteries were performed in Cohort II only. Psychosocial measures included social support and network participation, socioeconomic status, job strain, Type A behavior pattern, and John Henryism. All members of Cohort II were re-examined three years post-baseline. Cohort I members were not re-examined because they did not undergo Holter monitoring and ultrasonography. Prevalence and ischemic heart disease incidence analyses were performed using both cohorts. Baseline psychosocial factors were examined in relation to study endpoints which included extent of carotid atherosclerosis, presence of ischemia on exercise, presence of arrhythmias, tendency toward blood clotting, four year progression of atherosclerosis, and incidence of fatal and non-fatal ischemic heart disease.

The study was renewed in 1997. Data from a baseline examination, a four-year re-examination, and a proposed one-year re-examination of ultrasonographically assessed carotid and femoral atherosclerosis, and surveillance for myocardial infarctions and other outcomes, will be used to examine the progression or incidence of these outcomes in relation to changes in behavioral, psychosocial and socioeconomic factors. It will also be possible to see to to what extent the input of these behavioral, psychosocial and socioeconomic factors on cardiovascular disease (CVD) in 1,600 men and women is mediated by lipid peroxidation, hemostatic factors, and cardiovascular reactivity. Finally, the investigators state that this will be the first population-based epidemiologic study to examine the association between a carefully developed set of measures of cardiovascular reactivity to stress and the progression of carotid atherosclerosis, risk of myocardial infarction and death, and development of hypertension. The cohorts had previously been all male. Women were added when the study was renewed in FY 1997.