Endothelial function and hemodynamic responses during mental stress

Objective: The hemodynamic basis of blood pressure responses during psychol ogical stress shows striking individual differences that share an interesti ng similarity with risk for cardiovascular disease. Factors accounting for these individual differences are poorly understood. The present study exami ned the relationship of vascular endothelial function to stress-induced hem odynamic responses. Methods: Subjects were 40 healthy men and women, aged 2 5 to 44 years. Hemodynamic responses were assessed during exposure to a bat tery of four diverse laboratory stressors. Endothelium-dependent arterial d ilation (EDAD) was measured by ultrasound imaging of the brachial artery in response to reactive hyperemia. Results: High EDAD response was associated with lower resting systolic (p < .01) and diastolic blood pressure (p < .0 5). EDAD response was unrelated to blood pressure responses during stress. However, systemic Vascular resistance responses during laboratory stress we re significantly greater (p < .02) for individuals with low EDAD responses. Conclusions: Exaggerated systemic vascular resistance responses during str ess may reflect endothelial dysfunction. This association may help explain the growing evidence of a relationship between stress hemodynamics and card iovascular disease risk. The nature of this association is discussed in ter ms of a possible interplay between the sympathetic nervous system and the e ndothelium in regulation of vascular tone.