ABSTRACT
High blood pressure, elevated serum cholesterol, and advancing age have long been recognized as major risk factors for coronary heart disease (CHD) (1). Unfortunately, knowledge about these risk factors, either alone or in combination, does not predict most new cases of CHD. Moreover, the exact causal relationships between risk factors and CHD are not firmly established. Thus, for example, we know that the risk of atherosclerotic CHD is directly related to blood pressure level (2), but antihypertensive medications, which have been valuable in reducing mortality from stroke and congestive heart failure, have been far less successful in reducing CHD morbidity and mortality (3). This suggests that another variable or other variables may be mediating the relationship between elevated blood pressure and CHD.
