1028-121 Stressful Public Speaking Elevates Plasma β-Endorphins

Abstract

Public speaking psychological stress has previously been shown to be associated with silent ischemia. To test the hypothesis that psychological stress elevates plasma β-endorphin and that this changes pain threshold, we studied 20 patients with documented CAD and exercise induced ischemia, Following instrumentation and a 30 minute rest period, venous blood samples for β-endorphin were obtained prior to and immediately post psychological stress, Pain threshold was then assessed using a thermal probe technique at baseline and immediately post psychological stress. Patients gave 3 brief speeches lasting a total of 15 minutes about real life hassle situations.Empty CellBaselinePeak StressEmpty CellSBP (mmHg)138 ± 4180 ± 4HR (Beats/min)65 ± 378 ± 4Double Product9,047 ± 50814,240 ± 844Plasma β-endorphin (pMoI/L)4.3 ± 0.98.3 ± 2p < 0.05Pain Threshold (C°)45.0 ± 0.545.4 ± 0.5P = 0.18 There was a significant positive correlation between pain threshold post stress and β-endorphin post stress (r = 0,58, p = 0.008) In patients with CAD and exercise induced ischemia 1) public speaking produces psychological stress manifested by increased cardiovascular reactivity 2) public speaking causes an increase in plasma β-endorphin which is significantly correlated with pain thresholds 3) this may explain the predominance of silent ischemia during psychological stress in patients with CAD.