Insulin Metabolism, Sympathetic Nervous System Regulation, and Coronary Heart Disease Prevention
Neil Schneiderman Jay S. Skyler University of Miami
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 CHID. 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.
The incompleteness of our knowledge concerning CHD risk factors has led to a search for additional risk factors. These include: diabetes mellitus ( 4), smoking ( 5), obesity ( 6), physical inactivity ( 7), excessive alcohol consumption ( 8), poor dietary habits ( 9), and psychosocial variables such as Type A behavior pattern ( 10), hostility ( 11), depression ( 12), excessive fatigue ( 13), lack of social support ( 14, 15), occupational stress ( 16), and low socioeconomic status (SES) ( 17). Although the search for risk factors has been useful, it is necessary to understand the exact mechanisms by which they operate if we are to maximize our strategies for primary and secondary prevention.
The search for underlying causes of CHD has focused on increased understanding of metabolic mechanisms. In the present chapter, we intend to explore the hypothesis that insulin metabolism ( 18- 21) and stress hormones, including