Baroreflex sensitivity derived from the Valsalva manoeuvre: A physiological protective factor for anxiety induced by breathing CO2-enriched air.

ABSTRACT

This study aimed to determine the capacity of baroreflex sensitivity, derived from the Valsalva manoeuvre (BRS_v), to predict state anxiety induced by a biological stressor (CO2 inhalation). Healthy adults (n = 50) breathed 7.5 % CO2-enriched air for 8 min, preceded and followed by breathing medical air for 5 min. State anxiety was evaluated with a visual analogue scale. Anxiety sensitivity (Anxiety Sensitivity Index-3; ASI-3) and trait anxiety (Trait form of the State-Trait Anxiety Inventory; STAI_T) served as cognitive-affective predictors. BRS_v was adopted as a physiological predictor. Multiple regression analysis revealed that BRS_v predicted lower anxiety during CO2 exposure, and attenuated the effect of ASI-3 in increasing anxiety. No significant effects were found for STAI_T. This is the first study to identify baroreflex sensitivity as a strong protective physiological factor for anxiety beyond the effect of anxiety sensitivity.