Use of a Biofeedback Breathing App to Augment Poststress Physiological Recovery: Randomized Pilot Study

Background The speed of physiological recovery from stress may be a marker for cardiovascular disease risk. Stress management programs that incorporate guided breathing have been shown to moderate the stress response and augment recovery. Objective The aim of this study was to examine the effectiveness of an app-based brief relaxation intervention (BioBase) for facilitating physiological recovery in individuals exposed to a brief psychological stressor. Methods A total of 75 participants (44 women) completed a stressor speech task and were randomly assigned to one of three conditions: control, rumination, or an app-based relaxation breathing (BioBase) conditions. Heart rate variability (HRV) was assessed as a measure of autonomic function at baseline (6 min), during stress (6 min), and during recovery (6 min). Results There was a significant increase in subjective stress following stress exposure, but the ratings returned to baseline after recovery in all three groups. In addition, there was a significant decrease in vagally mediated HRV in the poststress period. During recovery, the root mean square of successive differences (P<.001), the percentage of successive interbeat (RR) intervals that differ by >50 ms (pNN50; P<.001), and high-frequency (P<.02) HRV were significantly higher in the BioBase breathing condition than the rumination and control conditions. There was no difference in HRV values between the rumination and control conditions during recovery. Conclusions App-based relaxed breathing interventions could be effective in reducing cardiovascular disease risk. These results provide additional utility of biofeedback breathing in augmenting physiological recovery from psychological stress.

Use of a Biofeedback Breathing App to Augment Poststress Physiological Recovery: Randomized Pilot Study (Preprint)

BACKGROUND The speed of physiological recovery from stress may be a marker for cardiovascular disease risk. Stress management programs that incorporate guided breathing have been shown to moderate the stress response and augment recovery. OBJECTIVE The aim of this study was to examine the effectiveness of an app-based brief relaxation intervention (BioBase) for facilitating physiological recovery in individuals exposed to a brief psychological stressor. METHODS A total of 75 participants (44 women) completed a stressor speech task and were randomly assigned to one of three conditions: control, rumination, or an app-based relaxation breathing (BioBase) conditions. Heart rate variability (HRV) was assessed as a measure of autonomic function at baseline (6 min), during stress (6 min), and during recovery (6 min). RESULTS There was a significant increase in subjective stress following stress exposure, but the ratings returned to baseline after recovery in all three groups. In addition, there was a significant decrease in vagally mediated HRV in the poststress period. During recovery, the root mean square of successive differences (P<.001), the percentage of successive interbeat (RR) intervals that differ by >50 ms (pNN50; P<.001), and high-frequency (P<.02) HRV were significantly higher in the BioBase breathing condition than the rumination and control conditions. There was no difference in HRV values between the rumination and control conditions during recovery. CONCLUSIONS App-based relaxed breathing interventions could be effective in reducing cardiovascular disease risk. These results provide additional utility of biofeedback breathing in augmenting physiological recovery from psychological stress.

Antagonism of specific corticotropin-releasing factor receptor subtypes selectively modifies weight loss in restrained rats

Rats exposed to 3 h of restraint stress on each of 3 days (RRS) lose weight on the days of RRS and gain weight at the same rate as controls after stress ends, but do not return to the weight of controls. RRS rats also show an exaggerated endocrine response to subsequent novel stressors. Studies described here tested the effects of corticotropin-releasing factor receptor (CRFR) antagonism on RRS-induced weight loss, hypophagia, and corticosterone release during mild stress in the postrestraint period. Weight loss was not prevented by either peripheral or third-ventricle administration of a CRFR1 antagonist, antalarmin, before each restraint. Antalarmin did, however, allow recovery of body weight in the poststress period. Third-ventricle administration of a CRFR2 antagonist, antisauvagine 30, had no effect in RRS rats but caused sustained weight loss in control animals. Surprisingly, third-ventricle administration of the nonselective CRFR antagonist, astressin, caused hypophagia and reversible weight loss in control rats. It had no effect in RRS rats. None of the antagonists modified the corticosterone response to RRS or to mild stress in the post-RRS period, but antalarmin suppressed corticosterone during the period of restraint in Control rats. These results suggest that CRFR1 activation is required for the initiation of events that lead to a prolonged down-regulation of body weight in RRS rats. The sustained reduction in body weight is independent of the severity of hypophagia on the days of restraint and of RRS-induced corticosterone release.

Hemodynamic response pattern predicts susceptibility to stress-induced elevation in arterial pressure in the rat

Cocaine or air jet stress evokes pressor responses due to either a large increase in systemic vascular resistance (vascular responders) or small increases in both cardiac output and vascular resistance (mixed responders) in conscious rats. Repeated cocaine administration results in elevated arterial pressure in vascular responders but not in mixed responders. The present study examined the hypothesis that the pattern of cardiovascular responses to an unconditioned stimulus (UCS; air jet) is related to responses to a conditioned stimulus (CS; tone followed by brief foot shock) in individual rats. Our data demonstrate that presentation of the UCS produced variable cardiac output responses that correlated with responses to the CS ( n = 60). We also determined whether individual cardiovascular response patterns to acute stress correlated with predisposition to a sustained stress-induced elevation in arterial pressure. Rats were exposed to three different stressors presented one per day successively for 4 wk and during a poststress period of 3 wk while arterial pressure was recorded periodically. Mean arterial pressure was elevated in all rats during chronic stress but, during the poststress period, remained at significantly higher levels in vascular responders but not mixed responders. Therefore, we conclude that acute behavioral stress to a conditioned stimulus elicits variable hemodynamic responses that predict the predisposition to a sustained stress-induced elevation in arterial pressure.

Evidence for adrenal insufficiency in acutely stressed captive monkeys

A number of postoperative complications in Macaca nemestrina suggested possible adrenal insufficiency secondary to chronic stress. Adrenal function was assessed by use of plasma 17-hydroxycorticoids, total eosinophil counts, and ACTH-response tests. Surgery or anesthesia resulted in a rise in plasma 17-hydroxycorticoids and a fall in total eosinophils in the majority of monkeys, and all of these animals demonstrated at least a 50% decrease in the total eosinophil count 4 hr following the intramuscular administration of ACTH. However, in three monkeys this type of response did not occur following one or both of the tests that were done. These three animals, unlike the others, presented one or more of the following complications during the poststress period: lethargy, failure to eat properly, diarrhea, and diuresis. These findings indicate that the stress of captivity may deplete adrenal reserve and alter normal physiological responses. primates (Macaca nemestrina); primates, adrenal reserve in primates, total eosinophil counts; primates, corticosteroid levels; adrenal reserve, evaluation of adrenal function, postoperative; captivity, adrenal exhaustion in Submitted on October 21, 1964