Acute Mental Stress Research Articles

Cardiac autonomic modulation in response to stress in normotensive young adults with parental history of hypertension.

Background Hypertension is the major health burden associated with increased cardiovascular morbidity and mortality. Positive family history and stress are the risk factors for hypertension. The present study aims to evaluate the effect of acute stress on the cardiac autonomic modulation in normotensive individuals with parental history of hypertension. Methods Sixty healthy male volunteers (30 with parental history of hypertension-NTPH+ group and 30 without parental history of hypertension-NTPH- group) in the age group of 18-24 years were included in the study. Short-term baseline heart rate variability (HRV) evaluation was done in frequency domain. Volunteers performed mental arithmetic stress task (MAST). HRV was measured before MAST, during MAST, and recovery period. HRV in both groups were compared. Results Analysis showed a significant increase in heart rate (p-value = 0.038) and systolic blood pressure (p-value = 0.01) in NTPH+ group compared to the NTPH- during MAST. NTPH+ group showed significantly higher LFnu (p-value = 0.03) and LF/HF ratio (p-value = 0.02) during MAST. Reduction in HFnu (p-value = 0.027) was significantly higher in the study group. ANOVA analysis demonstrated significant increase in LFnu [F(2.602, 75.46) = 18.60; p < 0.001; ηp2 = 0.391] and LF/HF ratio [F(1.76, 51.043) = 29.952; p < 0.001; ηp2 = 0.508] during MAST and 10 min of recovery period from baseline value in NTPH+ group. HFnu has significantly reduced during MAST and 5 min recovery period from baseline value in NTPH+ group [F(2.78, 80.72) = 12.77; p = 0.033, ηp2 = 0.28]. Conclusions Acute mental stress leads to exaggerated sympathetic response and vagal suppression in healthy individuals with parental history of HTN. This study concludes that HRV, which reflects autonomic flexibility, is lower during acute mental stress and post-stress recovery period in normotensive males with parental history of HTN.

Short-term HRV in young adults for momentary assessment of acute mental stress

Mental stress has become a major health threat in our society and its continuous monitoring and timely intervention is key to stress management. Heart rate variability (HRV) has been considered as a potential candidate for ecological momentary assessment of acute mental stress, and growing number of HRV metrics have been developed. However, inconsistency of findings in prior studies necessitates further investigation on what are the appropriate metrics in tracking the momentary variation of mental stress. This study employs a block design inducing low-high-low-high stress variation profile to test the feasibility of a broad range of HRV metrics for measuring the minute-scale stress variation elicited by the commonly used mental arithmetic tasks. After extracting the RR interval series, 42 HRV metrics have been examined in absolute reliability, relative reliability, and the statistical significance in differentiating the low and high stress levels. Among these metrics, 22 show absolute reliability, 21 show relative reliability, and 13 differentiate the low and high stress levels consistently across all four pairs of comparison. Venn’s diagram analysis resulted eight metrics hold both absolute and relative reliability, whereas those metrics robustly differentiating high and low stress levels hold either absolute (3/13) or relative (10/13) reliability. Our results show that, although not all HRV metrics hold both absolute and relative reliability, about one third of the examined HRV metrics can effectively track the variations of mental stress. These findings suggest the importance of HRV metrics selection when applied for monitoring acute mental stress.

Psychoneuroendocrinoimmunology-based meditation (PNEIMED) training reduces salivary cortisol under basal and stressful conditions in healthy university students: Results of a randomized controlled study

BackgroundMeditation represents an effective and safe practice to lower distress and promote well-being. PsychoNeuroEndocrinoImmunology-based Meditation (PNEIMED) is a validated method that can reduce stress-related symptoms and salivary cortisol secretion. To date, few randomised controlled trials (RCTs) have assessed cortisol levels through salivary samples, collected both in the morning phase and during acute mental stress elicitation, in healthy young subjects following brief meditation training. AimThe present study aims to investigate, in healthy young undergraduate students, the effects of a brief PNEIMED training course on HPA axis by measuring salivary cortisol levels. MethodsForty students attending the Faculty of Psychology, without comorbidities and previous experience of meditation, were enrolled in the study. Twenty subjects were randomly assigned to 30 h of PNEIMED training (intervention group, IG), and twenty subjects were randomly assigned to 30 h of academic lessons (control group, CG). Salivary cortisol measures included basal morning (t0 = baseline time, collected 30 min after waking) and under stress-eliciting task values. Cortisol measurement under the stress-eliciting task was provided through the Subtraction Stress Task (SST) at scheduled time intervals (t1 = 5 min pre-SST, t2 = 10 min post-SST, t3 = 30 min = post-SST). Salivary cortisol was measured among all subjects (IG + CG) at the beginning (pre-test) and at the end (post-test, four days later) of the study. ResultsANOVA between-group analysis of basal diurnal salivary cortisol showed a significant hormone deflection in the IG at the end of the PNEIMED course (post-test) when compared to the CG (IG post-test 5.64 ± 4.2 vs CG post-test 9.44 ± 4.9; F1,38 = 6.838; p = 0.013). RM-ANOVA within-group analysis for the IG also showed that time and condition effects were statistically significant, with Ftime = 5.438; p = 0.002 and Fcondition = 10.478; p = 0.004, respectively. The IG group presented a significant reduction in basal morning cortisol at the end of the PNEIMED course (post-test) compared to the salivary concentration at baseline (pre-test) (IG pre-test 9.42 ± 6.0 vs IG post-test 5.64 ± 4.2; F1,38 8,354; p = 0.009). RM-ANOVA for the control group showed only the main effect of time (F1,38 = 40.348; p < 0.001). Regarding cortisol measures under the SST-stress eliciting task, ANOVA between-groups analysis showed higher cortisol levels in the IG than in the CG before the PNEIMED course, with significant differences between groups at time t2 and time t3. After the PNEIMED course, the cortisol levels in the IG had decreased, although the differences between groups were not significant. Interestingly, ANOVA within-groups analysis showed that in the IG, the cortisol levels post-test (after the PNEIMED course) were lower than at pre-test (before the PNEIMED course), showing a significant difference of cortisol salivary concentration between conditions at t3 (F = 5.326; p = 0.032). In the control group, the post-hoc analyses for pairwise comparisons between conditions (pre-test vs post-test) did not show significant differences. ConclusionAlthough the low number of subjects enrolled in the study does not allow for definitive conclusions to be drawn, the present findings confirmed the capability of the PNEIMED method to lower stress hormone secretion both at baseline and under acute mental stimulation in a group of young naïve practitioners and make a contribution to the existing literature by increasing the number of published RCTs about the topic.

The salivary-α-amylase level after stroop test in anxious patients can predict the severity of anxiety

Individuals with anxiety disorder often exhibit as imbalance in response to stressors. We sought to explore the relationship between physiological as well as psychological responses under acute mental stress and the severity of the disease. 20 Generalized Anxiety Disorder (GAD) patients (14 males, mean age 46 ± 10 years) were confronted with the stroop test, during which salivary-α-amylase (sAA), salivary cortisol, and heart rate variability (HRV) were assessed. The results showed that stroop test as a stressor induced autonomic nervous response in GAD patients, which was mainly manifested as the increase in HRV representing sympathetic nervous system and the decrease in HRV representing vagal nerve activity. Moreover, the basic function of sympathetic-adrenal medulla system was hyperfunctional in GAD patients while theirs reactivity was limited, which showed the more serious the lesion was, the higher the baseline value of sAA was, and the less sAA secretion increase would be, or even decrease after mental stress. The change of sAA after stroop test in GAD patients can predict the severity of anxiety, but subjective psychological perception can not.

Cardiovascular Reactivity to Acute Mental Stress: THE IMPORTANCE OF TYPE D PERSONALITY, TRAIT ANXIETY, AND DEPRESSION SYMPTOMS IN PATIENTS AFTER ACUTE CORONARY SYNDROMES.

Links between psychophysiological reactions to stress stimuli and perceived mental distress, including type D personality, anxiety, and depression, are still under debate. The aim of this study was to examine associations between cardiovascular reactivity to social stress and mental distress in patients after acute coronary syndrome. Patients (n = 116, 86% males, 52 ± 8 yr) with coronary artery disease 2 wk after acute coronary syndrome were evaluated for sociodemographic, clinical characteristics and coronary artery disease risk factors. The Trier Social Stress Test was employed to measure cardiovascular reactions to social stress (systolic and diastolic blood pressure and heart rate). Mental distress assessment included type D personality (Type D Scale), anxiety and depressive symptoms (Hospital Anxiety and Depression Scale), and state and trait anxiety (State-Trait Anxiety Inventory). Multiple linear regression analysis showed associations between type D personality and lower heart rate during Trier Social Stress Test periods of task instruction (β = -.196, P < .04), preparation time (β = -.232, P < .01), and recovery time (β = -.209, P < .029). Higher trait anxiety was linked with lower heart rate during baseline rest (β = -.287, P < .01), task instruction (β = -.286, P < .01), preparation time (β = -.241, P < .01), and recovery period (β = -.209, P < .05). Depressive symptoms were associated with higher systolic blood pressure during baseline rest (β =.187, P < .05), task instruction (β = .306 P < .01), and free speech (β = .264, P < .05). Mental distress was associated with cardiovascular stress reactions independent from possible covariates, suggesting dysregulated psychophysiological reactions to acute stress.

Cerebrovascular regulation is not blunted during mental stress.

What is the central question of the study? What are the effects of acute mental stress on the mechanisms regulating cerebral blood flow? What is the main finding and its importance? The major new findings are as follows: (i) high mental stress and hypercapnia had an interactive effect on mean middle cerebral artery blood velocity; (ii) high mental stress altered the regulation of cerebral blood flow; (iii) the increased cerebrovascular hypercapnic reactivity was not driven by changes in mean arterial pressure alone; and (iv) this increased perfusion with mental stress appeared not to be justified functionally by an increase in oxygen demand (as determined by near-infrared spectroscopy-derived measures). In this study, we examined the effects of acute mental stress on cerebrovascular function. Sixteen participants (aged 23±4years; five female) were exposed to low and high mental stress using simple arithmetic (counting backwards from 1000) and more complex arithmetic (serial subtraction of 13 from a rapidly changing four-digit number), respectively. During consecutive conditions of baseline, low stress and high stress, end-tidal partial pressure of CO2 ( ) was recorded at normocapnia (37±3mmHg) and clamped at two elevated levels (P<0.01): 41±1 and 46±1mmHg. Mean right middle cerebral artery blood velocity (MCAvmean ; transcranial Doppler ultrasound), right prefrontal cortex haemodynamics (near-infrared spectroscopy) and mean arterial blood pressure (MAP; finger photoplethysmography) were measured continuously. Cerebrovascular hypercapnic reactivity (ΔMCAvmean /Δ ), cerebrovascular conductance (CVC; MCAvmean /MAP), CVC CO2 reactivity (ΔCVC/Δ ) and total peripheral resistance (MAP/cardiac output) were calculated. Acute high mental stress increased MCAvmean by 7±7%, and more so at higher (32±10%; interaction, P=0.03), illustrating increased sensitivity to CO2 (i.e. its major regulator). High mental stress also increased MAP (17±9%; P ≤ 0.01), coinciding with increased near-infrared spectroscopy-derived prefrontal haemoglobin volume and saturation measures. High mental stress elevated both cerebrovascular hypercapnic and conductance reactivities (main effect of stress, P ≤ 0.04). These findings indicate that the cerebrovascular response to acute high mental stress results in a coordinated regulation between multiple processes.

Peripheral Vasoconstriction During Mental Stress and Adverse Cardiovascular Outcomes in Patients With Coronary Artery Disease.

Excessive vasoconstriction in response to mental stress may be a potential mechanism by which acute psychological stress leads to adverse cardiac events. We investigated whether excessive digital vasoconstriction during acute mental stress predicts adverse cardiovascular outcomes among patients with coronary artery disease. Five hundred forty-nine patients with stable coronary artery disease (age 63±9, 76% male, 29% black) underwent mental stress testing with a standardized public speaking stressor and followed prospectively for cardiovascular end points. Digital pulse wave amplitude was continuously measured using peripheral artery tonometry (PAT, Itamar Inc). Stress/rest PAT ratio (sPAT) of pulse wave amplitude during mental stress/baseline was calculated and dichotomized by the median value into low and high sPAT ratio groups. Upon 3-year follow-up, Fine and Gray's subdistribution hazard ratios were used to examine the association between sPAT ratio and the composite end point of cardiovascular death, myocardial infarction, revascularization, and hospitalization for heart failure. The median sPAT ratio was 0.68 (interquartile range, 0.48-0.88), indicating 32% vasoconstriction with mental stress. Men were more likely to have low sPAT ratio than women (odds ratio, 1.79; P=0.007) while those on β-blockers were less likely to have low sPAT ratio (odds ratio, 0.52; P=0.003). After adjusting for demographic and cardiovascular risk factors, medications, and rate-pressure product change during mental stress, those with low sPAT ratio were at significantly higher risk of adverse outcomes (subdistribution hazard ratio, 1.77 [95% CI, 1.12-2.80]). Greater peripheral vasoconstriction with mental stress, denoted by a low sPAT ratio, is associated with a higher risk of adverse cardiovascular outcomes in patients with coronary artery disease.

Association of Transient Endothelial Dysfunction Induced by Mental Stress With Major Adverse Cardiovascular Events in Men and Women With Coronary Artery Disease

Acute mental stress can result in transient endothelial dysfunction, but the prognostic relevance of this phenomenon is unknown. To determine the association between mental stress-induced impairment in endothelium-dependent relaxation as assessed by brachial artery flow-mediated vasodilation and adverse cardiovascular outcomes among individuals with stable coronary artery disease. This cohort study was conducted at a university-affiliated hospital network between June 2011 and August 2014. A cohort of individuals with stable coronary artery disease were included. Data analysis took place from November 2018 to May 2019. Study participants were subjected to a laboratory mental stress task (public speaking). Flow-mediated vasodilation was measured before and 30 minutes after a public-speaking mental stress task. We examined the association of the rest (prestress), poststress, and δ flow-mediated vasodilation (poststress minus prestress levels) with an adjudicated composite end point of adverse events, including cardiovascular death, myocardial infarction, unstable angina leading to revascularization, and heart failure hospitalization, after adjusting for sociodemographic factors, medical history, and depression. A total of 569 patients were included (mean [SD] age, 62.6 [9.3] years; 420 men [73.8%]). Flow-mediated vasodilation decreased from a mean (SD) of 4.8% (3.7%) before mental stress to 3.9% (3.6%) after mental stress (a 23% reduction; P < .001), and 360 participants (63.3%) developed transient endothelial dysfunction (a decrease in flow-mediated vasodilation). During a median (interquartile range) follow-up period of 3.0 (2.9-3.1) years, 74 patients experienced a major adverse cardiovascular event. The presence of transient endothelial dysfunction with mental stress was associated with a 78% increase (subdistribution hazard ratio [sHR], 1.78 [95% CI, 1.15-2.76]) in the incidence of major adverse cardiovascular event. Both the δ flow-mediated vasodilation (sHR, 1.15 [95% CI, 1.03-1.27] for each 1% decline) and poststress flow-mediated vasodilation (sHR, 1.14 [95% CI, 1.04-1.24] for each 1% decline) were associated with major adverse cardiovascular event. Risk discrimination statistics demonstrated a significant model improvement after addition of either poststress flow-mediated vasodilation (change in the area under the curve, 0.05 [95% CI, 0.01-0.09]) or prestress plus δ flow-mediated vasodilation (change in the area under the curve, 0.04 [95% CI, 0.00-0.08]) compared with conventional risk factors. In this study, transient endothelial dysfunction with mental stress was associated with adverse cardiovascular outcomes in patients with coronary artery disease. Endothelial responses to stress represent a possible mechanism through which psychological stress may affect outcomes in patients with coronary artery disease.

Influence of Acute Mental Arithmetic Stress on Taste and Pungency.

Mental stress is a known risk factor for disease. This study investigated changes in sensations of taste and pungency before and after mental stress. Thirty healthy male university students rested for 20 min, performed mental arithmetic tasks for 10 min, and then underwent measurement of changes in their taste and ability to discern pungency. Taste was measured with the "Taste Disk®," and pungency was measured by a filter-paper disc method using capsaicin solution. Subjects were not told the order of the reagent solutions used. To quantify pain sensation, a weak current applied to the central inner forearm skin by a Pain Vision® quantitative pain sensation analyzer was gradually increased. The degree of stress was measured by portable electrocardiography (ECG). During mental stress, the cognitive threshold of salty taste, sweet taste, and bitterness was significantly decreased, whereas the sensations of pungency and forearm skin pain were increased and showed significant correlation. Based on sympathetic nerve activity analyzed with the ECG, the subjects were divided into the mental stress group and non-mental stress group. The mental stress group experienced an increase in the pungency threshold and sensation of forearm skin pain with significantly high correlations obtained, whereas no correlation was found between these factors in the non-mental stress group. Acute mental stress increased the sensitivity to taste but decreased the sensitivity to the sensation of pungency on the tongue and pain on the skin. Sympathetic activity activated by stress may affect taste and the sensation of pungency.

Impact of Stress on Resting Skeletal Muscle Oxygen Consumption with and without Prior Exercise

The effects of acute exercise on muscle metabolism are well established, however the impact of mental stress (MS) on muscle metabolism is not well understood. PURPOSE: To assess muscle oxygen consumption (mVO2) after acute MS and evaluate the effect of acute exercise prior to MS on mVO2. METHODS: Participants (N=15 males, 22± 2 yr, VO2peak 40.8 ± 5.7 ml/kg/min) served as their own control in a randomized counter balanced design. Participants completed a total of three visits over 3-5 weeks. On the initial visit, a maximal oxygen uptake test on a cycle ergometer was performed. Near-infrared spectroscopy (NIRS) was used during a five-minute cuff occlusion and the initial slope during the occlusion was used to assess mVO2 in the gastrocnemius muscle. mVO2 was assessed at baseline (BL), after rest (CON) or exercise (EX), and after mental stress (MS). On two separate days, participants either rested for 25 minutes (CON) or completed 25 minutes of exercise (EX) at 90% ventilatory threshold on cycle ergometer. MS was evoked by a serial subtraction test administered by two research assistants dressed in white lab coats. Data were analyzed using a 2x3 repeated measures ANOVA with Fishers LSD post hoc tests, and are presented as mean percent change +/- SD. RESULTS: A significant interaction effect of Condition x Time on mVO2 was observed(F=6.3 p<0.05,η2=0.326). Post hoc comparisons indicated mVO2 was significantly increased after EX compared to CON by 21.8+/- 26.0% (p<0.05). Within CON, MS increased mVO2 by 12.6 +/- 10.2% (p<0.001). In EX, there was an increase in mVO2 from BL to after EX by 12.6 +/- 16.0% (p<0.05) and from BL to after MS by 18.2 +/- 64.1% (p=0.053). CONCLUSION: To our knowledge, these data are the first to suggest that acute MS increases the metabolic rate of resting skeletal muscle. Interestingly, the combination of prior EX and MS does not further augment metabolic activity beyond MS alone.

Coping facilitated troponin T increases and hypo-responsivity in the copeptin-HPA-axis during acute mental stress in a black cohort: The SABPA study

BackgroundDefensive coping (DefS) was associated with a vulnerable cardiovascular profile in blacks. The copeptin/vasopressin system is a manifestation of hypothalamic-pituitary-adrenal-axis activity and may act as an acute compensatory mechanism when there is a disruption in volume-loading homeostasis, i.e. when cardiac stress is evident. Whether DefS will influence associations between copeptin and cardiac stress markers, remains unclear. Here we aimed to determine associations between acute mental stress responses of copeptin, vascular responsiveness and biomarkers of cardiomyocyte injury [cardiac troponin T (cTnT)] and cardiac wall-stress [N-terminal pro-brain natriuretic peptide (NT-proBNP)] in DefS race groups. MethodsSouth African black and white teachers (n = 378) of both sexes, participated in this target population study. Cases with a history of myocardial infarction, stroke and atrial fibrillation were excluded. We obtained coping scores (Coping Strategy Indicator), beat-to-beat blood pressure and fasting blood samples at rest and after 1-min exposure to the Stroop-Colour-Word-Conflict-test. ResultsInteraction effects (p < .05) for copeptin percentage change (%) during the Stroop-Colour-Word-Conflict-test determined stratification of participants into race and DefS (≥26, above-median score) groups. In DefS blacks, Stroop-Colour-Word-Conflict-test exposure elicited increases in cTnT%, NT-proBNP% and diastolic-blood pressure%. Again, in these individuals, multiple regression analyses showed positive associations between copeptin% and total peripheral resistance%; with inverse associations between copeptin% and cTnT% (p < .05). None of these associations were found in DefS whites. ConclusionsUtilisation of DefS in blacks provoked vascular hyper-responsiveness and cardiac wall stress (elevated cTnT and NT-proBNP); possibly mediated via the copeptin/vasopressin system. However, a presumably hypo-responsive hypothalamic-pituitary-adrenal-axis during stress exposure could not counteract coronary perfusion deficits via additional copeptin/vasopressin release. The presence of defensiveness may have clinical implications in preventive cardiology.

Early childhood trauma alters neurological responses to mental stress in patients with coronary artery disease

BackgroundEarly childhood trauma is known to independently increase adverse outcome risk in coronary artery disease (CAD) patients, although the neurological correlates are not well understood. The purpose of this study was to examine whether early childhood trauma alters neural responses to acute mental stress in CAD patients. MethodsParticipants (n = 152) with CAD underwent brain imaging with High Resolution Positron Emission Tomography and radiolabeled water during control (verbal counting, neutral speaking) and mental stress (mental arithmetic, public speaking). Traumatic events in childhood were assessed with the Early Trauma Inventory (ETI-SR-SF) and participants were separated by presence (ETI+) or absence (ETI-) of early childhood trauma. Brain activity during mental stress was compared between ETI+ and ETI-. ResultsCompared to ETI-, ETI+ experienced greater (p < 0.005) activations during mental stress within the left anterior cingulate, bilateral frontal lobe and deactivations (p < 0.005) within the left insula, left parahippocampal gyrus, right dorsal anterior cingulate, bilateral cerebellum, bilateral fusiform gyrus, left inferior temporal gyrus, and right parietal lobe. Significant (p < 0.005) positive correlations between brain activation and ETI-SR-SF scores were observed within the left hippocampus, bilateral frontal lobe, left occipital cuneus, and bilateral temporal lobe. LimitationsResults in non-CAD samples may differ and ETI may be subject to recall bias. ConclusionEarly childhood trauma exacerbated activations in stress-responsive limbic and cognitive brain areas with direct and indirect connections to the heart, potentially contributing to adverse outcomes in CAD patients.

Exploring common changes after acute mental stress and acute tryptophan depletion: Resting-state fMRI studies

Stress and low serotonin levels are important biological factors in depression and anxiety etiologies. Although studies indicate that low serotonin levels, stress, and other factors may interact in depression/anxiety psychopathology, few studies have investigated the potentially shared neural substrates. We conducted resting-state fMRI scans pre- and post-stress task, and under control and tryptophan depletion condition, to explore the common changes induced by acute mental stress (AMS) and acute tryptophan depletion (ATD). The present study targeted regions within core brain networks – default mode network, salience network, executive control network, and emotion network – reported altered in AMS and ATD, and used regional homogeneity (ReHo) and functional connectivity (FC) analyses to explore their overlapped effects. We additionally examined the relationships among core neural networks – operationalized as an index of resource allocation bias that quantifies the shift from internal to external modes of processing. We found both manipulations induced increased ReHo of the amygdala and decreased ReHo of the posterior cingulate cortex (PCC). The PCC-amygdala FC was negatively correlated with the change of negative affect, whereas the right dorsolateral prefrontal cortex and right anterior insula FC was positively associated with anxiety level. In addition, we found that a greater shift to an external mode was correlated with higher anxiety level under both conditions. Common changes induced by acute mental stress and acute tryptophan depletion confirmed our hypothesis that AMS and ATD induce changes in common neural pathways, which in turn might mark vulnerability to depression and anxiety.

Attenuated Mental Stress‐Induced Brachial Artery Hyperemia in Women Relative to Men

While the contributing factors resulting in hypertension and cardiovascular disease (CVD) are multifactorial, vascular dysfunction and exposure to chronic stress are key contributors. In this regard, previous research has indicated that men and women exhibit differential responses to stress. Acute mental stress (MS) elicits increases in peripheral blood flow that are predominately mediated by the actions of nitric oxide (NO) and thus is a technique that can be utilized to assess vascular function. Previous research has focused on sex differences in the response to MS in a variety of physiological variables; however, the impact of sex on the peripheral blood flow response to MS is less clear. Accordingly, the purpose of this study was to investigate the brachial BF hyperemic response during acute MS between men and women. We hypothesized that the hyperemic response to MS would be similar between the groups. Nine women (studied between days 2–7 of the follicular phase of the menstrual cycle) and seventeen men participated in this study. All measurements were obtained in the supine position following a 15 min baseline period. After the baseline period, the left arm was instrumented for continuous assessment of brachial artery diameter and blood velocity, which were used for subsequent calculation of brachial BF. Continuous arterial blood pressure was obtained on the contralateral arm for calculation of forearm vascular conductance (FVC; Flow/MAP). Brachial BF and FVC were continuously calculated during 2 min of baseline and 3 min of MS induced by asking subjects to subtract 7 continuously from a 3‐digit number while attempting to report answers at a pace set by a 60 bpm metronome. Compared to men, women had a reduced baseline blood flow (men: 84.39 ± 49.39 mL/min, women: 36.79 ± 15.41 mL/min; p = 0.01). In response to mental stress, women also had attenuated responses in the following variables: peak BF achieved during MS (men: 244.94 ± 119.06, women: 141.75 ± 86.98 ml/min; p = 0.03), total BF throughout the duration of MS (men: 408.91 ± 131.10, women: 196.84 ± 86.72 ml/min; p &lt; 0.01) and peak FVC achieved during MS (men: 2.86 ± 1.24, women: 1.13 ± 0.63 mL/min/mmHg; p &lt; 0.01). In conclusion, contrary to our hypothesis, these preliminary findings indicate that women had a reduced hyperemic response in the brachial artery during MS relative to men. Further research is warranted to assess mechanisms of these differential responses between sexes.Support or Funding InformationUTA Start‐up funds to R. Matthew BrothersThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

AT1R Blockade Inhibits Endothelial Dysfunction in Response to Mental Stress in Overweight/Obese Men

Acute exposure to mental stress (MS) leads to endothelial activation, microparticles release and, consequently, transient endothelial dysfunction in overweight/obesity grade 1 men. Considering that angiotensin II generates an oxidative imbalance mediated by angiotensin II type 1 receptors (AT1R), it is unknown whether this process is responsible for transient endothelial dysfunction present in MS in overweight/obesity grade 1. Therefore, the aim of this study was to determine endothelial responses to angiotensin II mediated by AT1R after MS in overweight/obesity grade I men. For this, fourteen overweight/obese men (27±7 years; 30.1±2.9 Kg/m2) participated in two randomized experimental sessions with oral administration of the AT1 receptor blocker (AT1R block) or placebo. Endothelial function was determined by flow‐mediated dilation (FMD) before (baseline), 30 (30MS) and 60 (60MS) minutes after a five minute session of acute MS (Stroop Color Word Test). Blood samples (n=11) were obtained at before (baseline), during (MS) and 60 minutes (60MS) after MS for measurement of: endothelial microparticle (EMP, flow cytometry); endothelial progenitor cells (EPC, flow cytometry); nitrite (chemoluminescence); and oxidative stress [lipid peroxidation (TBARS), protein oxidation (carbonylated proteins) and antioxidant enzyme (catalase) by colorimetry]. During MS, heart rate, systolic, diastolic and mean blood pressure increased similarly in both conditions (p=0.01 vs. baseline). At the placebo session, FMD decreased significantly in 30MS (p=0.04 vs. baseline) and returned to baseline levels in 60MS (p=0.03 vs. 30MS). There was a significant increase in EPC in 60MS (p=0.04 vs. baseline). Carbonylated proteins (p=0.01 vs. baseline) and catalase activity increased during MS (p=0.02 vs. baseline) and returned to baseline in 60MS (p=0.01 vs. MS). No differences were observed in nitrite levels at the placebo session. At AT1R block session, FMD increased in 30MS (p =0.01 vs. baseline) and 60MS (p=0.02 vs. baseline), while EPC levels were different from placebo only 60MS (p=0.04 vs. placebo). There was a significant increase in nitrite (p=0.01 vs. baseline) while no change was observed in carbonylated proteins in 30MS and 60MS. Carbonylated protein concentration was lower during AT1R blockade in MS (p=0.04 vs. placebo). Catalase increased only in 60EM (p=0.02 vs. placebo). There were no differences in the concentrations of EMP and TBARS. In conclusion, AT1R blockade appears to increase flow‐mediated dilatation and nitrite bioavailability in response to MS in addition to preventing the increase of protein oxidation after MS in overweight/obese men.Support or Funding InformationCoordination for the Improvement of Higher Education Personnel (CAPES)Foundation for Research Support of the State of Rio de Janeiro (FAPERJ)National Council for Scientific and Technological Development (CNPq)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ethnicity-Specific Changes in Cardiac Troponin T in Response to Acute Mental Stress and Ethnicity-Specific Cutpoints for the R Wave of the aVL Lead.

Acute mental stressor-induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007-2008 in South Africa. In the cross-sectional phase of the SABPA study, 388 black and white participants underwent a 1-minute acute mental stressor, during which blood pressure was continuously measured. Fasting blood samples for cardiac stress markers were obtained before and 10 minutes after stress (% change). Resting 10-lead electrocardiogram measured the R wave of the aVL lead (RaVL). Black participants exhibited greater cardiac stress responses (P < 0.001), diastolic blood pressure, total peripheral resistance, and stroke volume compared with white participants, who displayed decreases in cardiac stress and increases in cardiac output. Prestress and stressor cTnT cutpoints of 4.2 pg/mL predicted 24-hour, daytime, and nighttime diastolic hypertension in black participants (P < 0.001). These cTnT cutpoints were associated with an ethnicity-specific RaVL cutpoint of 0.28 mV (odds ratio = 3.49, 95% confidence interval: 2.18, 5.83; P = 0.021). Acute mental stress elicited an α-adrenergic activation pattern and cardiac stress hyperreactivity only in black participants. Mental stress might increase the black population's risk for ischemic episodes and heart disease.

Abstract P360: Blunted Hemodynamic Response to Acute Mental Stress Among African Americans With Coronary Heart Disease

Introduction: Racial differences in cardiovascular disease morbidity and mortality are well established by middle age with African Americans contributing to higher rates of cardiovascular disease. In addition to traditional risk factors, African Americans experience greater exposure to stressful life events. Both an enhanced and a blunted hemodynamic reactivity to acute psychological stress have been associated with worse cardiovascular health status and may contribute to these disparities. Methods: We studied 920 patients with stable coronary artery disease (CAD) and 109 controls without CAD. Systolic blood pressure (SBP), heart rate (HR), and rate-pressure product (RPP) were measured prior to, and following a public speaking stress task. We examined the association between race and hemodynamic reactivity to stress using mixed linear regression models adjusting for cardiovascular disease severity, medication usage and psychosocial, demographic and lifestyle factors. Results: Of the 920 patients (mean age 59 years), 39% were African American. African Americans had a more adverse socioeconomic and cardiometabolic profile (hypertension, diabetes, and body mass index) compared to white Americans. In response to mental stress, African American patients exhibited a lower increase in SBP (23 vs 27 mmHg; p &lt;.0001), HR (11 vs 13 beats/minute; p =0.008) and RPP (3205 vs 3718 mmHg x beat/min; p =0.004) compared to white Americans, after adjusting for demographics, lifestyle and medical risk factors. Among controls (41% African American), there were no significant differences in hemodynamic reactivity to mental stress by race, and among CAD patients, there were also no differences in the hemodynamic reactivity to an exercise stress test by race. Conclusions: African Americans with CAD exhibit a blunted hemodynamic response to mental stress compared to white Americans. Further research is needed to clarify the determinants of such differences and whether they contribute to race disparities in cardiovascular disease risk.

Computational Psychometrics Using Psychophysiological Measures for the Assessment of Acute Mental Stress

The goal of this study was to provide reliable quantitative analyses of psycho-physiological measures during acute mental stress. Acute, time-limited stressors are used extensively as experimental stimuli in psychophysiological research. In particular, the Stroop Color Word Task and the Arithmetical Task have been widely used in several settings as effective mental stressors. We collected psychophysiological data on blood volume pulse, thoracic respiration, and skin conductance from 60 participants at rest and during stressful situations. Subsequently, we used statistical univariate tests and multivariate computational approaches to conduct comprehensive studies on the discriminative properties of each condition in relation to psychophysiological correlates. The results showed evidence of a greater discrimination capability of the Arithmetical Task compared to the Stroop test. The best predictors were the short time Heart Rate Variability (HRV) indices, in particular, the Respiratory Sinus Arrhythmia index, which in turn could be predicted by other HRV and respiratory indices in a hierarchical, multi-level regression analysis. Thus, computational psychometrics analyses proved to be an effective tool for studying such complex variables. They could represent the first step in developing complex platforms for the automatic detection of mental stress, which could improve the treatment.

Sex differences in interleukin-6 stress responses in people with Type 2 diabetes.

People with Type 2 diabetes (T2D) show dysregulated inflammatory responses to acute stress, but the effect of sex on inflammatory responses in T2D remains unclear. The purpose of this study was to investigate differences in interleukin (IL)‐6 stress responses between older men and women with T2D. One hundred and twenty‐one people (76 men; mean age = 64.09, SD = 7.35, 45 women; mean age = 63.20, SD = 6.70) with doctor‐verified T2D took part in this laboratory‐based stress testing study. Participants carried out acute mental stress tasks, and blood was sampled at baseline, immediately poststress, 45 min poststress, and 75 min poststress to detect plasma IL‐6 concentrations. IL‐6 change scores were computed as the difference between the baseline measurement and the three time points poststress. Main effects and interactions were tested using mixed model analysis of covariance. We found a significant main effect of time on IL‐6 levels, and a significant Sex × Time interaction. In adjusted analyses including the three change scores and all the covariates, the significant Sex × Time interaction was maintained; IL‐6 responses were greater in women at 45 and 75 min poststress compared with men, adjusting for age, body mass index, smoking, household income, glycated hemoglobin, oral antidiabetic medication, insulin/other injectable antidiabetic medication, depressive symptoms, and time of day of testing. Different inflammatory stress response pathways are present in men and women with T2D, with women producing larger IL‐6 increases. The long‐term implications of these differences need to be elucidated in future studies.

A Comparative Study of Heart Rate Variability During Acute Mental Stress in Obese

A Comparative Study of Heart Rate Variability During Acute Mental Stress in Obese