BETA-ENDORPHIN RESPONSE TO EXERCISE AND MENTAL STRESS IN PATIENTS WITH ISCHEMIC-HEART-DISEASE

We compared symptomatic, hemodynamic and opioid responses of heart disease patients to exercise testing and a stressful public speaking task. Plasma beta-endorphins were measured at rest and immediately post stress. Nineteen of 50 patients had angina during exercise; 31 had asymptomatic ischemia. No patient had angina during the speech, but two had ECG changes and 39% had radionuclide changes indicating ischemia. Patients with asymptomatic ischemia on exercise had a significantly greater beta-endorphin response than those with angina. Public speaking elicited a significantly larger beta-endorphin increase relative to change in double product (an index of stress) than did exercise. Conclusions: (1) Patients with silent vs painful ischemia experience a greater beta-endorphin response to exercise. (2) beta-endorphin response to a speech stressor is greater than to exercise when controlled for an index of stress. (3) Increased beta-endorphin response to a speech stressor may partially explain the predominance of silent ischemia during psychological stress.