Israel Ischemic Heart Disease Study

Background/Question:

The Israel Ischemic Heart Disease Study started in 1963 to analyze factors having a positive or negative correlation with ischemic heart disease. The study cohort was followed for 23 years with the first results published after two years, in 1971.

Population/Methods:

The study population was civil servants living in Israel, having origins outside as well as inside Israel. It ranged from 40 to 75 years, and included 10,059 men, 86.5 percent of those asked to participate. The variables examined focused in six areas: genetic, sociodemographic, clinical, biochemical, behavioral, and psychosocial.

Results:

Among genetic factors, blood type correlated with higher rates of infarction. The study also risk related to birth location. Subjects having an entry diagnosis in 1963 of angina pectoris, peripheral arterial disease, and diabetes mellitus showed a significantly higher rate of infarction during the first five years. The clinical factors of weight-height ratio, blood pressure, and pulse rate all showed a direct association with risk of infarction. Blood pressure levels were more associated with infarction if the measurements varied than if they were stable. Abnormalities in the electrocardiographic readings at entry showed an association with incidence of myocardial infarction. Biochemical measurements of serum cholesterol, hemoglobin, hematocrit, cholesterol in beta lipoprotein, and glucose all showed an association with infarction. Risk for infarction was also higher for smokers. Problem with superiors at work was associated with higher risk of infarction and religious beliefs with lower risk.

Conclusions/Discussion:

The Israel Ischemic Heart Disease Study data were used for other research on physical activity and diabetes, and on serum cholesterol and coronary heart disease mortality. Physical activity, for example, predicted lower coronary and total mortality rates.

This study was unique in its early support from the U.S. National Heart Institute, for its interest in the effect of different origins of the Jewish immigrant populations, and for its collaboration among several disciplines early in the field of CVD epidemiology. It was also pioneering in the use of computer-diagnosed electrocardiograms. The 1975 report indicates higher than predicted infarction rates (based on a traditional risk factors score) in those from Poland, Germany and USSR and lower than expected from Iraq and Yemen, which they felt was compatible with the idea that unknown risk factors influenced risk. Diabetes and its complications were also related to country of origin. (FB/HB)