Cold Pressor Stress Research Articles

Cold pressor stress effects on cardiac repolarization

The cold pressor test (CPT) elicits strong cardiovascular reactions via activation of the sympathetic nervous system (SNS), yielding subsequent increases in heart rate (HR) and blood pressure (BP). However, little is known on how exposure to the CPT affects cardiac ventricular repolarization. Twenty-eight healthy males underwent both a bilateral feet CPT and a warm water (WW) control condition on two separate days, one week apart. During pre-stress baseline and stress induction cardiovascular signals (ECG lead II, Finometer BP) were monitored continuously. Salivary cortisol and subjective stress ratings were assessed intermittently. Corrected QT (QTc) interval length and T-wave amplitude (TWA) were assessed for each heartbeat and subsequently aggregated individually over baseline and stress phases, respectively. CPT increases QTc interval length and elevates the TWA. Stress-induced changes in cardiac repolarization are only in part and weakly correlated with cardiovascular and cortisol stress-reactivity. Besides its already well-established effects on cardiovascular, endocrine, and subjective responses, CPT also impacts on cardiac repolarization by elongation of QTc interval length and elevation of TWA. CPT effects on cardiac repolarization share little variance with the other indices of stress reactivity, suggesting a potentially incremental value of this parameter for understanding psychobiological adaptation to acute CPT stress.

Muscle sympathetic nerve activity during pregnancy: A systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to quantify the impact of healthy and complex pregnancy on muscle sympathetic nerve activity (MSNA) at rest, and in response to stress. Structured searches of electronic databases were performed until February 23, 2022. All study designs (except reviews) were included: population (pregnant individuals); exposures (healthy and complicated pregnancy with direct measures of MSNA); comparator (individuals who were not pregnant, or with uncomplicated pregnancy); and outcomes (MSNA, BP, and heart rate). Twenty-seven studies (N=807) were included. MSNA burst frequency was higher in pregnancy (n=201) versus non-pregnant controls (n=194) (Mean Differences [MD], MD: 10.6 bursts/min; 95% CI: 7.2, 14.0; I2 =72%). Accounting for the normative increase in heart rate with gestation, burst incidence was also higher during pregnancy (Pregnant N=189, non-pregnant N=173; MD: 11 bpm; 95% CI: 8, 13 bpm; I2 =47%; p < 0.0001). Meta-regression analyses confirmed that although sympathetic burst frequency and incidence are augmented during pregnancy, this was not significantly associated with gestational age. Compared to uncomplicated pregnancy, individuals with obesity, obstructive sleep apnea, and gestational hypertension exhibited sympathetic hyperactivity, while individuals with gestational diabetes mellitus or preeclampsia did not. Uncomplicated pregnancies exhibited a lesser response to head-up tilt, but an exaggerated sympathetic responsiveness to cold pressor stress compared to non-pregnant individuals. MSNA is higher in pregnant individuals and further increased with some, but not all pregnancy complications. PROSPERO registration number: CRD42022311590.

Immediate and Delayed Salivary Cytokine Responses during Repeated Exposures to Cold Pressor Stress

Introduction: Excessive stress is increasingly recognized as an important trigger of many diseases prevalent in modern societies, and monitoring such stress-related effects could aid prevention. The measurement of salivary markers of inflammation is emerging as a promising tool to non-invasively quantify stress’ effects on immune processes in everyday life and thereby detect early aberrations before the manifestation of serious health problems. However, more laboratory-controlled research is needed in order to establish the timescale and determinants of salivary cytokine responses to acute stress. Methods: We repeatedly exposed participants to Cold Pressor Stress Test (CPT) or a control procedure and measured a wide array of salivary cytokines as well as subjective, cardiovascular, and cortisol stress reactions. CPT exposure was repeated every 15 min, 3 times in total, with a duration of 3 min each. Saliva was sampled immediately after the first two exposures as well as in 15-min intervals until 60 min after the onset of the first intervention. Results: We found that many cytokines were detectable in saliva. Specific stress effects were limited to IL-8 and IL-6, however, which decreased immediately or 15 min after stress onset, respectively. Moreover, IL-8 was negatively correlated to cortisol output in the stress but not in the control group. Significant increases were also observed in salivary TNFα and IFNγ; however, these effects were similar under both stress and control conditions. Discussion: Our results show that particular salivary cytokines may be sensitive to immediate effects of acute CPT-induced stress and also highlight the importance of employing control procedures to discern stress effects from unrelated variations in salivary cytokines.

Higher cardiovascular activation, but normal heartbeat-evoked potentials and cardiac interoceptive accuracy in somatoform disorders and major depressive disorder

The perception-filter model posits that the generation of medically-unexplained symptoms is associated with (I.) more intense afferent bodily signals, (II.) impaired filter system activity to differentiate relevant from irrelevant signals, and (III.) altered perception of bodily signals. We tested these assumptions for cardiac perception in patients with somatoform disorders (SFD), patients with major depressive disorder (MDD) and healthy control (HC) individuals. Heart rate (variability; HR/HRV) and blood pressure served as indicators of bodily signals (I.); heartbeat-evoked potentials (HEPs) assessed during a heartbeat counting task (HCT) and a distraction task indicated filter system activity (II.); interoceptive accuracy (IAc) in the HCT was interpreted as an index of perception (III.). All indicators were assessed before and after a socially-evaluated cold pressor stress task (SECPT) and a control intervention. SFD patients (n ​= ​24) showed higher average HR and diastolic blood pressure, as well as lower HRV than HC individuals (n ​= ​22), but there were no differences in HEPs or IAc. Neither were there significant differences between the SFD and the MDD groups (n ​= ​24), nor any stress effect on HEPs or IAc. Our findings suggest that increased intensity of bodily signals (I.) is the only model assumption that could be supported for patients with fully-developed SFD. • We investigated interoception in somatoform disorders (SFD) and depression (MDD). • SFD and MDD patients had higher heart rate (HR) and blood pressure than controls. • Heartbeat-evoked potentials did not differ between SFD, MDD patients and controls. • Cardiac interoception did not differ between SFD, MDD patients and controls. • Acute stress did not affect heartbeat-evoked potentials and cardiac interoception.

Stress-induced HPA activation in virtual navigation and spatial attention performance

BackgroundPrevious research has shown that spatial performance (e.g. navigation, visuospatial memory, attention) can be influenced by acute stress; however, studies have produced mixed findings sometimes showing an improvement after stress, other times showing impairment or no overall effect. Some of these discrepancies may be related to: the type of stress system activated by the stressor (sympathetic adrenal medulla [SAM] or hypothalamic-pituitary-adrenocortical [HPA]); whether cortisol responders vs. nonresponders are analyzed subsequent to main effects; and sex differences in stress responses. In the present study, we examine the influence of HPA activation from an acute laboratory stressor (Socially Evaluated Cold Pressor test [SECPT]) on performance during two spatial tasks: Useful Field of View (UFOV; a measure of spatial attention) and virtual reality (VR) navigation. We assigned 31 males and 30 females to either the SECPT or a Non-Stress condition prior to the two spatial tasks. Cardiovascular measures including heart rate and blood pressure, and salivary cortisol biosamples were obtained at specific time points.ResultsParticipants in the Stress condition showed increases in heart rate, systolic and diastolic blood pressure indicating sympathetic adrenal medulla (SAM) axis activation. Stress also led to increases in salivary cortisol, suggesting hypothalamic-pituitary-adrenocortical (HPA) activation. Stress did not influence overall performance in the spatial attention UFOV or the VR navigation task. However, a sex difference in spatial attention was detected when participants were divided into Stress-cortisol responders and non-responders in the UFOV task. Male Stress-cortisol responders (n = 9) showed better UFOV accuracy than female Stress-cortisol responders (n = 6); no sex differences were found among the Non-Stress control group. Furthermore, for females in the stress condition (n = 14), higher cortisol responses were associated with lower spatial attention performance.ConclusionsSocially Evaluated Cold Pressor stress resulted in no change in speed or accuracy in a VR navigation task. For the spatial attention task, the SECPT led to a sex difference among Stress-cortisol responders with males showing improved accuracy over females. The relationship between HPA activation and prefrontal cortex activity may be necessary to understand sex differences in spatial attention performance.

Embodiment of an Emotional State Concurs with a Stress-Induced Reconsolidation Impairment Effect on an Auditory Verbal Word-List Memory

Stress alters memory. Understanding how and when acute stress improves or impairs memory is a challenge. Stressors can affect memory depending on a combination of factors. Typically, mild stressors and stress hormones might promote consolidation of memory processing and impair memory retrieval. However, studies have shown that during reconsolidation, stressors may either enhance or impair recalled memory. We propose that a function of reconsolidation is to induce changes in the behavioral expression of memory. Here, we adapted the Rey Auditory Verbal Learning Test (RAVLT) to evaluate the effect of cold pressor stress (CPS) during the reconsolidation of this declarative memory. A decay in memory performance attributable to forgetting was found at the time of memory reactivation 5 d after training (day 6). Contrary to our initial predictions, the administration of CPS after memory reactivation impaired long-term memory expression (day 7), an effect dependent on the presence of a mismatch during Reactivation Session. No differences in recognition tests were found. To assess putative sources of the negative memory modulation effects induced during reconsolidation, current emotional state was evaluated immediately after Testing Session (day 7). An increase in arousal was revealed only when CPS was administered concurrently with memory reactivation–labilization. The possibility of integration during reconsolidation of independent associations of these emotive components in the trace is a critical factor in modulating neutral memories during reconsolidation by stressors.

130 Individual Differences in Skin Temperature Responses to Cold Pressor Stress During Sleep Restriction and Circadian Misalignment

Abstract Introduction Individual differences in cognition during sleep restriction and circadian misalignment have been shown to be trait-like. Here we explored the consistency of individual differences in cardiovascular responses to the cold pressor test (CPT) measured by changes in the distal-proximal skin temperature gradient (DPG) using the contralateral hand to that immersed in the ice water bath, which reflects a reflex cutaneous vasoconstriction. Methods Eighteen healthy participants (8 females) mean (±SD) age 25.28 (±4.3), underwent two identical in-laboratory combined sleep restriction and circadian misalignment protocols preceded by an 8h baseline in-laboratory sleep opportunity. The participants were given a 3h sleep opportunity on night 2 and a 3h sleep opportunity on days 3 and 4 followed by recovery sleep. The CPT occurred the morning after the baseline sleep opportunity and the morning before recovery sleep. Participants maintained a seated posture beginning 30 min prior to the CPT and skin temperature was assessed starting 15 min before until 45 min after the CPT. DPG (proximal=subclavicular; distal=hand palmar) data were averaged into 3 min bins. Changes in DPG from pre-CPT and 5 min post-CPT were assessed as the primary outcome using mixed-model ANOVAs. Intra-class correlation coefficients (ICC) were calculated to measure consistency of individual differences for DPG responses. Results Mixed-model ANOVA revealed significant effects of time and combined sleep restriction and circadian misalignment on DPG during the CPT (both p&amp;lt;0.05), such that the DPG was wider (i.e., more negative) post-CPT and during sleep restriction and circadian misalignment. Participants showed moderately consistent DPG responses across visits 1 and 2 at baseline (ICC=0.59) and substantially consistent DPG responses during sleep restriction and circadian misalignment (ICC=0.67). Further, participants showed moderately consistent DPG responses when comparing changes between baseline and sleep restriction and circadian misalignment across visits (ICC=0.58). Conclusion Findings support that combined sleep restriction and circadian misalignment is associated with sympathetic activation and that individual differences in the DPG response to cold pressor stress are consistent. Support (if any) Office of Naval Research MURI grant N00014-15-1-2809, NIH/NCATS Colorado CTSA Grant UL1TR002535

Changes in sympathetic nervous system activity after renal denervation: results from the randomised Oslo RDN study

Purpose Sympathetic nervous system (SNS) over-activity is associated with essential hypertension. Renal sympathetic denervation (RDN) possibly lowers office- and ambulatory blood pressure (BP) in patients with treatment-resistant hypertension (TRH). We aimed to assess the effect of RDN compared to drug adjustment on SNS activity among patients with TRH by measuring plasma catecholamines and heart rate variability (HRV) during stress tests. Materials and methods Patients with TRH were randomised to RDN (n = 9) or Drug Adjustment (DA) (n = 10). We measured continuous HRV and beat-to-beat-BP using FinaPres® and obtained plasma catecholamines during standardised orthostatic- and cold-pressor stress tests (CPT) before- and six months after randomisation. Results CPT revealed no differences between groups at baseline in peak adrenaline concentration (69.3 pg/mL in the DA group vs. 70.0 pg/mL in the RDN group, p = 0.38) or adrenaline reactivity (Δ23.1 pg/mL in the DA group vs. Δ29.3 pg/mL in the RDN group, p = 0.40). After six months, adrenaline concentrations were statistically different between groups after one minute (66.9 pg/mL in the DA group vs. 55.3 pg/mL in the RDN group, p = 0.03), and six minutes (62.4 pg/mL in the DA group vs. 50.1 pg/mL in the RDN group, p = 0.03). There was a tendency of reduction in adrenaline reactivity after six months in the RDN group (Δ26.3 pg/mL at baseline vs. Δ12.8 pg/ml after six months, p = 0.08), while it increased in the DA group (Δ13.6 pg/mL at baseline vs. Δ19.9 pg/mL after six months, p = 0.53). We also found a difference in the Low Frequency band at baseline following the CPT (667µs2 in the DA group vs. 1628µs2 in the RDN group, p = 0.03) with a clear tendency of reduction in the RDN group to 743µs2 after six months (p = 0.07), compared to no change in the DA group (1052µs2, p = 0.39). Conclusion Our data suggest that RDN reduces SNS activity after six months. This finding warrants investigation in a larger study. Clinical Trial Number registered at www.clinicaltrials.gov: NCT01673516

Acute Exposure to the Cold Pressor Stress Impairs Working Memory Functions: An Electrophysiological Study.

The results of previous literature focusing on the effects of acute stress on human working memory (WM) are equivocal. The present study explored the effects of acute stress on human WM processing using event-related potential (ERP) techniques. Twenty-four healthy participants were submitted to stressful treatments and control treatment at different times. Cold pressor stress (CPS) was used as stressful treatment, while warm water was used as the control treatment before the WM task. Exposure to CPS was associated with a significant increase in blood pressure and salivary cortisol. After the 3-min resting period, systolic blood pressure (SBP) and diastolic blood pressure (DBP) for the CPS session significantly increased relative to the control treatment session (all p ≤ 0.01), and data also showed a significant increase of 20-min post-treatment cortisol concentration (p < 0.001) for CPS. Data from the CPS session showed significantly longer reaction times, lower accuracy, and WM capacity scores than that of the control treatment session. Interestingly, a difference between the two sessions was also found in N2pc and the late contralateral delay activity (late CDA) components. Specifically, although non-significant main effects of treatment were found for N2pc amplitudes, there was a significant interaction between treatments and stimuli conditions (processing load) [F(2,46) = 3.872, p = 0.028, η2 p = 0.14], which showed a pronounced trend toward equalization of N2pc amplitude across stimuli conditions during the CPS session clearly different from that of control treatment. As for amplitudes for late CDA, a nearly significant main effect of Treatment was found (p = 0.069). That is, the mean amplitude of the late CDA (−2.56 ± 0.27) for CPS treatment was slightly larger than that (−2.27 ± 0.22) for warm water treatment. To summarize, this study not only reported performance impairments in the WM task during CPS trials but also provided high temporal resolution evidence for the detrimental effects of acute stress on processes of information encoding and maintenance.

Brain activity during a post-stress working memory task differs between the hormone-present and hormone-absent phase of hormonal contraception

Taking hormonal contraceptives (HCs) affects the magnitude of the hormonal stress response and cognition. HCs are usually administered in a monthly cycle with both synthetic-hormone-containing and synthetic-hormone-absent phases. The synthetic hormones contained in HCs affect a wide range of neurophysiological systems, suggesting that effects of the medication might only be observed during the synthetic-hormone-containing phase of the HC cycle. To test this, women were seen twice, once during the hormone-present phase and once during the hormone-absent phase of the HC cycle. In each session, women performed an n-back working memory task to assess pre-stress performance outside of the magnetic resonance imaging scanner, were then exposed to cold pressor stress, and again completed the n-back task during functional magnetic resonance imaging. The free cortisol response to stress remained the same across the HC cycle. Women also performed comparably on the n-back task after stress exposure across the two phases. However, despite these similarities, women displayed greater disengagement of default mode network as task demands increased during the hormone-present phase only, a pattern more in line with working memory-related brain activation under non-stressful conditions reported in other studies. The results suggest that the synthetic hormones contained in HCs may mitigate stress-related disruptions of typical brain activation patterns during the hormone-present phase of the HC cycle, despite exhibiting comparable cortisol responses across the HC cycle. Additional research is required to determine the mechanisms contributing to, and the extent of, such mitigating effects.

High blood pressure responders show largest increase in heartbeat perception accuracy after post-learning stress following a cardiac interoceptive learning task

Mental disorders with physical symptoms, e.g. somatic symptom disorder, are characterized by altered interoceptive accuracy (IAc), which can be explained by individual differences in interoceptive learning (IL). We investigated if stress facilitates IL. Seventy-three healthy participants performed a heartbeat counting task (HCT: T1) and a heartbeat perception training (HBPT). After exposure to a socially-evaluated cold pressor stress test (SECPT; n = 48) or a control condition (n = 25), two more HCTs were performed (T2: 30 min after SECPT; T3: 24 h later). After the HBPT, all participants showed an increase in IAc. We separated the stress group into high vs. low systolic blood pressures (SBP) responders (n = 24 each), with high SBP responders showing the largest IAc increases. Only SBP, but not cortisol responsiveness significantly predicted IAc increase from T1 to T2. Our results indicate that post-learning autonomic stress response facilitates IL, whereas the HPA axis response may be less important for this effect.

Childhood Trauma Affects Stress-Related Interoceptive Accuracy.

Early life adversity (ELA) may cause permanent disturbances in brain–body signaling. These disturbances are thought to contribute to physical symptoms and emotional dysregulation in adulthood. The current study investigated the effects of childhood trauma on young adults’ interoceptive accuracy as an indicator of brain–body communication that may be dysregulated by ELA. Sixty-six participants completed an online questionnaire followed by a laboratory session including the socially evaluated cold pressor stress test during which ECG, salivary cortisol, and interoceptive accuracy were assessed. Childhood trauma was negatively related to interoceptive accuracy (IAc) after the stressor. This stress effect could not be observed for heart rate and cortisol, which were unrelated to IAc. Participants reporting higher baseline unpleasantness exhibited lower IAc after the stressor, while increases in unpleasantness due to the stressor were associated with higher IAc. Unpleasantness at baseline mediated the effect of childhood trauma on IAc after the stressor.

Preliminary examination of the orexin system on relapse-related factors in cocaine use disorder

Rationale. Current evidence and literature reviews provide a strong justification for examining the orexin receptor (OXR) system as a therapeutic target in substance use disorders, including cocaine and other psychostimulants. Objectives. In this preliminary, proof-of-concept examination of orexin modulation in humans with cocaine use disorder, we measured changes in domains tied to relapse: stress, sleep, cue reactivity, and inhibitory control. Additionally, mood symptoms (anxiety, depression), medication compliance, and side effects were assessed. Methods. Twenty non-treatment seeking subjects with cocaine use disorder (CUD) received either the OX1R / OX2R antagonist suvorexant PO or placebo at 10 PM daily for two weeks (10 mg week 1, 20 mg week 2). Using psychometrics, smart-watch actigraphy, a cold-pressor stress challenge, and eye-tracking technology, the following domains were examined: sleep, stress/anxiety, cue-reactivity (attentional bias, craving), and inhibitory control. Psychometric data were collected every M/W/F (7 time points). Laboratory data were collected weekly (3 time points). Results. Bayesian and frequentist generalized linear models were employed in parallel to examine the effects of suvorexant compared to placebo, with a Bayesian posterior probability threshold >80% as evidence of a signal for suvorexant. Notable results favoring suvorexant over placebo included fewer total anti-saccade errors, improved sleep actigraphy (sleep/awake periods), pre/post cold-pressor change in heart rate and salivary cortisol (all posterior probabilities >94%), and craving (posterior probability >87%). Conclusions. Initial but restricted evidence is provided supporting the orexin system as a modulator of relapse-related processes in cocaine use disorder. Baseline differences in the main outcome variables were not experimentally controlled and differences in craving were observed at baseline. This, in combination with a limited sample size, constrain the nature of the project. The results may serve to inform more comprehensive future research.

HIV-1 Infection, Injecting Drug Use, and Neuroendocrine Response to Psychological Stress.

Previous studies have suggested that HIV-1 infection is associated with neuroendocrine abnormalities including alterations in autonomic nervous system (ANS) activity. The norepinephrine (NE) response to cold pressor stress, an α-adrenergic challenge, is blunted in HIV-1 infection. Given the relation of ANS activity to the function of the hypothalamic-pituitary-adrenal (HPA) axis and its role in cognitive functioning, changes in response to stress may be a factor in HIV-related cognitive dysfunction. In this study, we evaluated the NE and cortisol response of persons in three groups. We studied stress response in three groups: (1) those with HIV-1 infection and a history of injecting drug use (IDU), those with HIV-1 infection but no IDU, and a control group of uninfected individuals without a history of IDU. Stress was induced by administering a neuropsychological test known to induce an immediate increase in NE, the Stroop Color-Word Test. Blood samples were obtained immediately before and after participants completed the Stroop and then at two intervals over the next 20 minutes. Data were analyzed using mixed-effects repeated measures models. Serum norepinephrine, epinephrine, and cortisol. Analyses showed that those with both HIV-1 infection and history of IDU had a significantly greater NE response to stress that did not return to baseline over 20 minutes compared to those without infection or IDU history. Epinephrine and cortisol responses followed similar patterns, but between-group differences were not statistically significant. The combination of history of IDU and HIV infection may produce an exaggerated neuroendocrine response that does not quickly return to baseline levels. Given the potential impact of these on cognitive and physical function in affected these individuals, implementing stress management techniques with them may be important.

Emotional stress regulation: The role of relative frontal alpha asymmetry in shaping the stress response

Frontal EEG asymmetry has been proposed as an index of emotional regulation, reflecting both state and trait components, and there is evidence that these factors influence the cortisol response to stress. Here, we asked whether cold pressor stress modulates frontal asymmetry and whether this is predictive of the neuroendocrine stress response. Twenty-four male participants underwent an automatized bilateral feet cold pressor test (bfCPT) and a warm water control procedure in counterbalanced order on two separate days, one week apart. EEG, heart rate and blood pressure were assessed at baseline as well as during and after the bfCPT. Salivary cortisol and subjective ratings of stress and arousal were assessed before and after the bfCPT. The bfCPT led to a significant increase in cortisol, cardiovascular parameters and in subjective ratings of stress and arousal that was absent in the control condition. Furthermore, analysis of relative frontal alpha-band asymmetry revealed a stronger relative right frontal activation during the bfCPT compared to the control condition at electrode pairs F7/8 but not F3/4. However, frontal asymmetry scores during the bfCPT were not predictive for neither physiological responses nor subjective ratings. Moreover, an association between physiological responses and frontal asymmetry assessed during rest at baseline could be observed at electrode pairs F3/F4, with stronger responses being associated with stronger relative right frontal activation. Our results show that cold pressor stress leads to an alteration of emotional processes as reflected in frontal EEG asymmetry at F7/F8. Moreover, physiological responses to the CPT seem to be differentially moderated by trait and state components present in frontal asymmetry.

The effects of acute stress on the calibration of persistence

People frequently fail to wait for delayed rewards after choosing them. These preference reversals are sometimes thought to reflect self-control failure. Other times, however, continuing to wait for a delayed reward may be counterproductive (e.g., when reward timing uncertainty is high). Research has demonstrated that people can calibrate how long to wait for rewards in a given environment. Thus, the role of self-control might be to integrate information about the environment to flexibly adapt behavior, not merely to promote waiting. Here we tested effects of acute stress, which has been shown to tax control processes, on persistence, and the calibration of persistence, in young adult human participants. Half the participants (n = 60) performed a task in which persistence was optimal, and the other half (n = 60) performed a task in which it was optimal to quit waiting for reward soon after each trial began. Each participant completed the task either after cold pressor stress or no stress. Stress did not influence persistence or optimal calibration of persistence. Nevertheless, an exploratory analysis revealed an “inverted-U” relationship between cortisol increase and performance in the stress groups, suggesting that choosing the adaptive waiting policy may be facilitated with some stress and impaired with severe stress.

Perinatal Depression, Adverse Life Events, and Hypothalamic–Adrenal–Pituitary Axis Response to Cold Pressor Stress in Latinas: An Exploratory Study

BackgroundLatinas are disproportionately affected by perinatal depression (PND) as well as by adverse life events (ALEs), an independent predictor of PND. Dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis has been seen both in women with PND and with a history of ALEs in non-Latinas. Although some evidence suggests that HPA axis dysregulation may mediate the link between ALEs and PND, this hypothesis has received little attention and there are no studies that have examined these pathways in Latinas. The primary aim of the present study was to explore, in a Latina sample, associations between ALEs, PND, and HPA axis stress reactivity to a physical stressor, the cold pressor test (CPT). The secondary aim was to explore whether HPA axis reactivity and PND were associated with pain sensitivity to the CPT. MethodsThirty-four Latinas were enrolled in their third trimester of pregnancy and interviewed at 4 and 8 weeks postpartum. Depression status was determined using the Edinburgh Postnatal Depression Scale (≥10). At 8 weeks postpartum, 27 women underwent laboratory-induced pain testing using the CPT. Plasma adrenocorticotropic hormone and cortisol were sampled before and after the CPT to generate a stress reactivity score (post–pre). Pain sensitivity and ALEs were also assessed. ResultsAt enrollment, 26% of women were depressed, and 18% were depressed at 8 weeks postpartum. Fifty-two percent reported at least one childhood ALE. There was a significant and positive association between any childhood ALE and prenatal depression scores (p = .025). Infant-related ALEs were significantly associated with greater adrenocorticotropic hormone reactivity to the CPT (p = .030). Women with a history of any childhood ALE exhibited a blunted cortisol response to the CPT (p = .045). Women with a history of PND at 4 weeks had greater adrenocorticotropic hormone stress reactivity to the CPT (p = .027). No effects of PND were seen for pain sensitivity measures in response to the CPT, although there was a positive and significant correlation between pain tolerance and cortisol response to the CPT in the whole sample. ConclusionsGiven the associations between ALEs and PND and their individual effect on HPA axis stress reactivity, future studies on PND should include a larger sample of Latinas to test the mediating effects of HPA axis reactivity on associations between ALEs and PND.

Retrieval under stress decreases the long-term expression of a human declarative memory via reconsolidation

Acute stress impairs memory retrieval of several types of memories. An increase in glucocorticoids, several minutes after stressful events, is described as essential to the impairing retrieval-effects of stressors. Moreover, memory retrieval under stress can have long-term consequences. Through what process does the reactivated memory under stress, despite the disrupting retrieval effects, modify long-term memories? The reconsolidation hypothesis proposes that a previously consolidated memory reactivated by a reminder enters a vulnerability phase (labilization) during which it is transiently sensitive to modulation, followed by a re-stabilization phase. However, previous studies show that the expression of memories during reminder sessions is not a condition to trigger the reconsolidation process since unexpressed memories can be reactivated and labilized. Here we evaluate whether it is possible to reactivate-labilize a memory under the impairing-effects of a mild stressor. We used a paradigm of human declarative memory whose reminder structure allows us to differentiate between a reactivated-labile memory state and a reactivated but non-labile state. Subjects memorized a list of five cue-syllables associated with their respective response-syllables. Seventy-two hours later, results showed that the retrieval of the paired-associate memory was impaired when tested 20min after a mild stressor (cold pressor stress (CPS)) administration, coincident with cortisol levels increase. Then, we investigated the long-term effects of CPS administration prior to the reminder session. Under conditions where the reminder initiates the reconsolidation process, CPS impaired the long-term memory expression tested 24h later. In contrast, CPS did not show effects when administered before a reminder session that does not trigger reconsolidation. Results showed that memory reactivation-labilization occurs even when retrieval was impaired. Memory reactivation under stress could hinder -via reconsolidation- the probability of the traces to be expressed in the long term.

Acute Effects of Moderate Continuous Training on Stress Test-Related Pulse Pressure and Wave Reflection in Healthy Men.

Arterial dysfunction develops early in life even in individuals with modest cardiovascular risk. Stress is associated with increased risk in cardiovascular morbidity and mortality. The main objectives of this study were to investigate the acute effects of moderate continuous training (MCT) on established markers of arterial stiffness and cardiovascular risk during standardized cold pressor stress testing (CPT). 29 young healthy male subjects (33.7±8years, BMI 24±2kg/m2) performed a 60-min period of moderate upright bicycle exercise with 65% of maximum heart rate. Before (t0), 45 (t45) as well as 60 (t60) min after exercise peripheral pulse pressure (PP) as well as augmentation index at a set heart rate (AIx@75) were assessed non-invasively at rest using an oscillometric device. Immediately after t0 and t60 PP and AIx@75 were registered at the end of a 2min CPT. PP (p=0.005) and AIx@75 (p=0.04) were reduced below pre-exercise level at t60. In contrast to CPT before exercise, there were significant reductions in PP (p=0.039) as well as AIx@75 (p=0.002) during CPT after exercise. Additionally, there was a negative correlation between maximal oxygen consumption and AIx@75 (r=-0.42, p=0.044). Acute MCT decreased PP and reduces AIx@75 after 60min of recovery. Furthermore, PP and AIx@75 showed reduced values after completion of MCT indicating attenuated hemodynamic response to stress testing after MCT. Moreover, higher physical conditioning status was associated with more favorable effects on stress test-related arterial compliance.

Do women tend while men fight or flee? Differential emotive reactions of stressed men and women while viewing newborn infants

Infant care often is carried out under stressful circumstances. Little is known about differences in caretaking motivation between men and women under stress. In the present study, stress was induced in 40 participants (21 women, 19 men) by means of the cold pressor stress test, 40 (22 women, 18 men) serving as controls. Participants then rated their urge to care for newborn infants shown on 20 short video clips. The infants in the videos were either crying (N=10) or were showing typical neonatal facial movements (N=10). Skin conductance was obtained while participants viewed the videos and salivary cortisol was measured to capture stress responses. We found sex differences in caretaking motivation, such that stress led to decreased caretaking motivation in men but not in women. Furthermore, stressed men elicited a stronger skin conductance change while viewing infant videos than stressed women. These findings provide further evidence for differential stress reactions in men and women and may have crucial implications for parental care.