Abstract:

A cluster of negative personality traits such as trait anxiety, trait depression, trait anger, trait hostility, has long been viewed as high risk factors that lead to cardiovascular diseases. Patterns of stress cardiovascular responses are the important physiological pathways through which personality traits influence cardiovascular diseases. In the past decades, studies exploring the associations between negative personality traits and patterns of stress cardiovascular responses have mainly focused on a specific negative trait and its cardiovascular responses to a single low/moderate stress exposure, however, no study to date has differentiated two types of negative traits and their relations with patterns of cardiovascular responses to repeated stress exposure under distinct intensity conditions. The present study sought to investigate the associations between avoidance vs. approach negative traits and the patterns of cardiovascular responses to two successive stress exposures under moderate and high intensity psychosocial stress conditions. Moreover, the potential mechanisms underlying these associations were preliminarily explored by considering the mediating role of stress cognitive appraisals.

Eligible 167 healthy undergraduate students recruited from universities in Xi'an (58 males, 109 females), aged 17~25 years (19.23 ± 1.13), took part in the present study. Upon arrival, participants completed a package of questionnaires including trait depression, trait anxiety, trait anger, and trait hostility. Then, participants were randomly assigned to either moderate- or high-intensity psychosocial stress condition, and underwent four laboratory phases: baseline, stress exposure 1, post-stress 1, stress exposure 2. Hierarchical multiple regression analyses were utilized to examine the main effects of stress intensity, avoidance and approach negative traits, as well as interaction effects of negative traits and stress intensity in predicting cardiovascular reactivity to, cardiovascular recovery from stress, and cardiovascular reactivity to repeated stress. Furthermore, mediation effect analyses were conducted to explore whether the associations between negative traits and stress cardiovascular reactivity were mediated by cognitive appraisals.

Results showed that the mock interview tasks used for both two stress exposures were effective in eliciting subjective and physiological stress responses. Intensity of psychosocial stress was successfully manipulated, with high-intensity stress elicited greater psychophysiological responses than low-intensity stress. Regression analyses showed that regardless of the stress intensity, avoidance negative trait predicted blunted stress cardiovascular reactivity to the first and second stress exposures, and predicted poor cardiovascular recovery after the stress exposure. Whereas, approach negative trait predicted greater stress cardiovascular reactivity to the first and second stress exposures, and predicted poor cardiovascular recovery after the stress exposure. In addition, mediation analyses showed that the association between avoidance negative trait and HR reactivity to repeated stress was mediated by perceived personal resources to repeated stress.

Overall, the present study findings suggest that both two types of negative trait are associated with a rigid stress cardiovascular response pattern in coping with a changing environment. In specific, avoidance negative trait is associated with blunted stress cardiovascular reactivity and poor cardiovascular recovery, whereas approach negative trait is associated with greater stress cardiovascular reactivity and poor cardiovascular recovery, implying differential physiological mechanisms underlying cardiovascular diseases.

Key words: avoidance negative trait, approach negative trait, stress cardiovascular response patterns, cognitive appraisals