Consistency in Physiological Stress Responses and Electromyographic Activity during Induced Stress Exposure in Women and Men

Physiological responses serve the role as objective indicators of stress as well as a link between psychosocial stress and various health outcomes. The aim of the present exposure session was to compare different physiological stress responses (systolic and diastolic blood pressure, heart rate, urinary epinephrine and norepinephrine, salivary cortisol) as well as trapezius muscle activity, measured by surface electromyography, during mental and physical stress in 11 women and ten men. The results show significantly increased activity in all measures but cortisol and significant associations between sympathetic arousal and EMG activity. The association between sympathetic arousal and muscle activity is of importance for understanding the high prevalence of musculoskeletal disorders in mentally stressful but physically light work tasks. Men had higher blood pressure and a more pronounced increase in epinephrine output than women, whereas women had higher heart rate. It was concluded that sympathetic activity is more sensitive to moderately intense stress exposure than pituitary adrenocortical (cortisol) activity and that men respond to performance stress with more epinephrine output than women. Although the correlations between the different indicators of sympathetic arousal were high, together they could still only explain 30-70% of the inter-individual variance. Thus, several parameters are needed in order to obtain a reliable measure of sympathetic activity.     

Chronic stress influences cardiovascular and neuroendocrine responses during acute stress and recovery, especially in men.

This study tests the influence of chronic stress on cardiovascular and neuroendocrine responses to and recovery from acute stressors and whether the effects are gender specific. Sixty-two healthy, middle-aged persons (50% women) performed mental-arithmetic and public-speaking tasks and relaxed thereafter for 1 hr while their cardiovascular and neuroendocrine function was measured. Participants with higher levels of chronic stress showed lower systolic blood pressure (SBP) and epinephrine (E; men only) and marginally lower levels of norepinephrine (NE) responses to the tasks and showed lower levels of cortisol and marginally lower NE responses during recovery. Relative to women, men had high diastolic blood pressure (DBP) responses to the tasks and high SBP, DBP, and E responses during recovery. Gender differences in cardiovascular disease in midlife may be due to gender differences in the inability to recover quickly, in addition to enhanced acute-stress response.     

Lipid reactivity to stress: II. Biological and behavioral influences.

This study examined behavioral and physiological influences on lipid concentrations during acute and chronic stressors. One hundred men (n = 92) and women (n = 8) were tested during a chronic stressor and during 2 acute stressors. During chronic stress, diet, physical activity, exercise, and sleep were examined. During the acute stressors, catecholamines, cortisol, plasma volume, and cardiovascular responses were examined. None of the behavioral influences could explain the lipid response to chronic stress. Responses of the atherogenic lipids to acute stressors were not solely reflecting hemoconcentration of the plasma but were moderately correlated with cardiovascular, epinephrine, and cortisol reactivity. Diastolic blood pressure reactors to the acute stressors had larger lipid responses to the chronic stressor than did nonreactors. Elevations in blood lipids during stress are not artifacts and may be clinically significant.     

Gender differences in cardiovascular and hypothalamic-pituitary-adrenal axis responses to psychological stress in healthy older adult men and women

Gender differences in the neuroendocrine and cardiovascular response to psychological stress may contribute to the gender differences in the prevalence of diseases associated with hypothalamic-pituitary-adrenal (HPA) axis reactivity such as cardiovascular disease (CVD), diabetes and hypertension. We measured plasma ACTH, cortisol, heart rate (HR), and blood pressure (BP) responses in 8 men and 8 women (55-75 years) exposed to the Matt Stress Reactivity Protocol (MSRP), a psychological challenge. The MSRP elicited significant increases in HR, systolic-, and diastolic BP, ACTH and cortisol (all p<0.01). Men had significantly greater cortisol and diastolic BP responses compared to women (p<0.05). Additionally, a positive correlation between the ACTH and cortisol responses was only found in the males (r=0.71, p<0.05). There were no group differences in HR, systolic BP, or ACTH responses. We conclude, that among older adults, men respond to psychological stress with greater increases in cortisol, compared to women. This greater activation of the HPA axis could translate into an elevated risk for CVD, diabetes and hypertension and may be related to the higher prevalence of these diseases in males. Gender differences in brain structures and/or cognitive processes may be responsible for these sexually dimorphic stress responses.     

Effects of pre-learning stress on memory for neutral, positive and negative words: Different roles of cortisol and autonomic arousal

Stress can have enhancing or impairing effects on memory. Here, we addressed the effect of pre-learning stress on subsequent memory and asked whether neutral and emotionally valent information are differentially affected by specific stress components, autonomic arousal and stress-induced cortisol. Ninety-six healthy men and women underwent either a stressor (modified cold pressor test) or a control warm water exposure. During stress, participants showed comparable autonomic arousal (heart rate, blood pressure), while 60 percent showed an increase of cortisol (responders vs. 40 percent non-responders). Ten minutes after the cold pressor test neutral, positive and negative words were presented. Free recall was tested 1 and 24 h later. Overall, positive and negative words were better recalled than neutral words. Stress enhanced the recall of neutral words independently of cortisol response. In contrast, the free recall of negative words was enhanced in cortisol responders in the 1-h but not 24-h test which might suggest different effects of cortisol on consolidation and reconsolidation processes. Recall for positive words was unaffected by stress-induced cortisol. To summarize, (i) pre-learning stress can enhance memory for neutral words independently of cortisol and (ii) stress effects on memory for negative words appear to rely on stress-induced cortisol elevations, the absence of this effect for positive words might be at least partly due to differences in arousal evoked by positive vs. negative words.     

Individual response differences in spider phobia: comparing phobic and non-phobic women of different reactivity levels

In contrast to previous stress research, studies concerning phobic disorders have never systematically investigated individual response differences between phobic participants integrating numerous different response measures. The aim of this article is to clarify the existence of significant individual response differences in psychophysiological responses (e.g., heart rate, skin conductance responses (SCR), corrugator, cortisol), subjective ratings (e.g., valence, arousal), and avoidance behavior in 46 spider phobic and 44 non-phobic women when exposed to 20 phobic and 20 neutral pictures. Previous studies that did not attend to individual response differences showed that, during phobic stimulation, phobic individuals have increased psychophysiological responses (heart rate, SCR, and corrugator responses), more negative valence rating, and more subjective arousal than non-phobic individuals. These results were confirmed by our data. With regard to individual response uniqueness, 1/3-2/3 of spider-phobic women with low responsiveness in heart rate, cortisol, and avoidance behavior were indistinguishable from non-phobic women during phobic stimulation. With SCR, corrugator EMG, and subjective ratings, no individual response uniqueness was found. Based on the findings, exposure therapy might be improved by tailoring interventions to individuals with a therapeutic focus on those psychophysiological measures that show the highest individual responsivity.     

Cardiovascular and neuroendocrine activity in preschool children: Comparison between day-care and home levels

Thirty boys and 30 girls at nine day-care centers were examined at the mean age of 3.5 and 5.5 with regard to systolic and diastolic blood pressure, heart rate and neuroendocrine activity (urinary catecholamines and cortisol) during a day at their day-care center and in their home, respectively. Compared to home levels, day-care was associated with increased heart rate, epinephrine and norepinephrine excretion and decreased cortisol levels. Systolic blood pressure decreased at the day-care centers at the age of 3.5 and increased at the age of 5.5. No significant sex differences were found. The possible role of mental and physical arousal and the dissociation between the sympathetic-adrenal medullary and the pituitary-adrenal cortical responses are discussed.     

Biological basis of the stress response

Chronic, as well as acute emotional arousal, is a consequence of various types of social interaction, i.e., those between mother and infant and between controlling dominant and less effective subordinate. The neurohumoral accompaniments of this social stress include the sympathetic adrenal medullary and hypothalamic pituitary adrenal responses. A common ensuing pathophysiological state involves a chronic increase of blood pressure. Although Selye’s General Adaptation Syndrome presupposed the same response to a variety of stimuli; recent work shows that specific perceptions of control result in different patterns of neuroendocrine activation. A challenge perceived as easy to handle will elicit an active coping response and release of the neurosympathetic system’s norepinephrine. Testosterone will rise as the subject savors success. With increasing anxiety this active coping shifts to a more passive mode and the behavior becomes less assured as the animal loses control. The norepinephrine/epinephrine ratio decreases as epinephrine, prolactin, renin and fatty acids rise. As the outcome becomes still less certain and distress grows, adrenocorticotropic hormone and cortisol levels arise. Thus, the effort required on the one hand and the degree of frustration conflict and uncertainty on the other, determine the ratio of catecholamines to corticoids. With severe emotional trauma, brain dysfunction may occur. These effects can be lasting, and corticoids paradoxically return to normal as the behavior changes to that of post-traumatic stress disorder. Repression and denial set in and the organism responds with decreased concern of impaired attachment and increased irritability.     

Biological basis of the stress response.

Chronic, as well as acute emotional arousal, is a consequence of various types of social interaction, i.e., those between mother and infant and between controlling dominant and less effective subordinate. The neurohumoral accompaniments of this social stress include the sympathetic adrenal medullary and hypothalamic pituitary adrenal responses. A common ensuing pathophysiological state involves a chronic increase of blood pressure. Although Selye's General Adaptation Syndrome presupposed the same response to a variety of stimuli; recent work shows that specific perceptions of control result in different patterns of neuroendocrine activation. A challenge perceived as easy to handle will elicit an active coping response and release of the neurosympathetic system's norepinephrine. Testosterone will rise as the subject savors success. With increasing anxiety this active coping shifts to a more passive mode and the behavior becomes less assured as the animal loses control. The norepinephrine/epinephrine ratio decreases as epinephrine, prolactin, renin and fatty acids rise. As the outcome becomes still less certain and distress grows, adrenocorticotropic hormone and cortisol levels arise. Thus, the effort required on the one hand and the degree of frustration conflict and uncertainty on the other, determine the ratio of catecholamines to corticoids. With severe emotional trauma, brain dysfunction may occur. These effects can be lasting, and corticoids paradoxically return to normal as the behavior changes to that of post-traumatic stress disorder. Repression and denial set in and the organism responds with decreased concern of impaired attachment and increased irritability.     

Individual response differences in spider phobia: Comparing phobic and non-phobic women of different reactivity levels

Abstract

In contrast to previous stress research, studies concerning phobic disorders have never systematically investigated individual response differences between phobic participants integrating numerous different response measures. The aim of this article is to clarify the existence of significant individual response differences in psychophysiological responses (e.g., heart rate, skin conductance responses (SCR), corrugator, cortisol), subjective ratings (e.g., valence, arousal), and avoidance behavior in 46 spider phobic and 44 non-phobic women when exposed to 20 phobic and 20 neutral pictures. Previous studies that did not attend to individual response differences showed that, during phobic stimulation, phobic individuals have increased psychophysiological responses (heart rate, SCR, and corrugator responses), more negative valence rating, and more subjective arousal than non-phobic individuals. These results were confirmed by our data. With regard to individual response uniqueness, 1/3–2/3 of spider-phobic women with low responsiveness in heart rate, cortisol, and avoidance behavior were indistinguishable from non-phobic women during phobic stimulation. With SCR, corrugator EMG, and subjective ratings, no individual response uniqueness was found. Based on the findings, exposure therapy might be improved by tailoring interventions to individuals with a therapeutic focus on those psychophysiological measures that show the highest individual responsivity.     

Enhancing effects of acute psychosocial stress on priming of non-declarative memory in healthy young adults

Social stress affects cognitive processes in general, and memory performance in particular. However, the direction of these effects has not been clearly established, as it depends on several factors. Our aim was to determine the impact of the hypothalamus-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) reactivity to psychosocial stress on short-term non-declarative memory and declarative memory performance. Fifty-two young participants (18 men, 34 women) were subjected to the Trier Social Stress Task (TSST) and a control condition in a crossover design. Implicit memory was assessed by a priming test, and explicit memory was assessed by the Rey Auditory Verbal Learning Test (RAVLT). The TSST provoked greater salivary cortisol and salivary alpha-amylase (sAA) responses than the control task. Men had a higher cortisol response to stress than women, but no sex differences were found for sAA release. Stress was associated with an enhancement of priming but did not affect declarative memory. Additionally, the enhancement on the priming test was higher in those whose sAA levels increased more in response to stress (r(48)?=?0.339, p?=?0.018). Our results confirm an effect of acute stress on priming, and that this effect is related to SNS activity. In addition, they suggest a different relationship between stress biomarkers and the different memory systems.     

Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge

The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms; however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure; however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.     

Selective cardiovascular effects of stress and cigarette smoking in young women

In an earlier study, we found that men who smoked a cigarette and then engaged in a mildly stressful activity (video game) evidenced pronounced increases in heart rate and blood pressure, which were approximately equal to the sum of the effects produced by either smoking alone or stress alone. In the present study, a 2 (smoke vs. sham smoke) X 2 (stress vs. no stress) factorial design was used to evaluate the impact of stress and smoking on the cardiovascular responses of young women. The results revealed that the combination of stress and cigarette smoking produced blood pressure and heart rate responses that were larger than the additive effects of smoking and stress taken separately.     

The effects of cortisol increase on long-term memory retrieval during and after acute psychosocial stress

In this study the effects of stress-induced cortisol increases on long-term memory retrieval during and after acute psychosocial stress were examined. Seventy male students were exposed to either a psychosocial stress task or to a non-stressful control task. During and after this task, retrieval was tested for idiosyncratic emotionally negative and neutral word pair associations that were learned 1 day or 5 weeks earlier. Within the stress condition, retrieval of negative words, 5 weeks after learning, was impaired both during and after the stress task compared to the control group. Further, during the stress task, when sympathetic activity was enhanced, impaired retrieval of both neutral and emotional words was significantly related to enhanced cortisol response. In contrast, after the stress task, when cortisol levels were still increased but sympathetic activity was low again, no association was found between cortisol increase and retrieval of either neutral or emotional material. These results are in line with the previous animal research showing that when arousal is high, cortisol increase can impair memory retrieval.     

Repression-sensitization,gender, and discrepancies in psychobiological reactions to examination stress

Psychobiological responses to examination stress in repressors and sensitizers have rarely been investigated with respect to intraindividual response discrepancies. Furthermore, possible sex differences have rarely been taken into consideration. Therefore the present study investigated if repressors and sensitizers differ in their psychobiological responses to stress and if gender plays a modulating role. 30 and 29 students of both sexes selected from a total group of 96 students were classified as repressors or sensitizers each according to the repression-sensitization-coping-inventory (RSCI, Huwe et al.). State anxiety, heart rate, and cortisol in saliva served as indicators of stress. Sensitizers reported higher state anxiety and showed higher physiological stress responses than repressors. On the intraindividual level sensitizers reported high anxiety as compared to their low cortisol responses whereas repressors reported low anxiety as compared to their high cortisol increases. Gender had no modulating influence on stress responses in repressors and sensitizers.     

Timing is everything: Anticipatory stress dynamics among cortisol and blood pressure reactivity and recovery in healthy adults

Psychological states of anticipation modulate biological stress responsivity. While researchers generally investigate how subjective distress corresponds to the magnitude of stress reactivity, physiological recovery after acute stressors must also be considered when investigating disease vulnerabilities. This study assessed whether anticipatory stress would correspond to stress reactivity and recovery of salivary cortisol and blood pressure levels in response to a well-validated psychosocial stressor. Thirty participants (63% female; mean?±?SEM age 45.4?±?2.12 years) were exposed to the Trier Social Stress Test (TSST) consisting of a public speech and mental arithmetic. Ten salivary cortisol samples and systolic and diastolic blood pressure recordings were collected at time points spanning 50?min before and up to 50?min after stress exposure. These data were transformed into parameters representing stress reactivity (area under the curve) and stress recovery (percent change). The Primary Appraisal Secondary Appraisal scale assessed anticipatory stress before exposure to the TSST. Our results revealed that increased anticipatory stress predicted increased stress reactivity for cortisol (p?=?0.009) but not blood pressure. For stress recovery, increased anticipatory stress predicted greater decrements of cortisol concentration (p?=?0.015) and blood pressure (p?=?0.039), even when controlling for total systemic "output" by incorporating baseline activity. This efficient shutdown of stress responses would have otherwise been ignored by solely investigating reactive increases. These findings underscore the importance of measuring multiple dynamic parameters such as recovery when investigating physiological stress response patterns as a function of psychosocial factors.     

Psychosocial stress and HPA functioning: no evidence for a reduced resilience in healthy elderly men

In order to investigate if HPA functioning is altered with age, the present study was conducted. Fifteen healthy elderly men (60-76 years; mean age 66.5 +/- 1.48 yrs.) and 12 younger adults (20-29 years; mean age 25.6 +/- 0.77 yrs.) collected salivary free cortisol profiles after awakening for basal HPA activity. Then, all subjects were exposed to the "Trier Social Stress Test" (TSST). This psychosocial stress protocol consists of a free speech and a mental arithmetic task of 13 minutes duration performed in front of an audience. Beside the assessment of endocrine and cardiovascular responses to the stressful task ratings of depression, mood and perceived stressfulness were obtained. Results show that younger and elderly men had similar morning cortisol profiles after awakening with both groups showing the expected rise after awakening (P=0.004). The TSST induced significant increases in ACTH, total plasma cortisol, saliva free cortisol, and heart rates (all P<0.0001). Regardless of age, both age groups showed comparable endocrine response patterns when confronted with the stressor. However, cardiovascular responses were significantly higher in younger men compared to elderly men (P=0.03). Catecholamine data revealed significant norepinephrine and epinephrine increases due to the stressor (both P<0.0001) with a trend toward elevated norepinephrine levels in elderly men (P=0.058). In sum, the investigated basal and response parameters of HPA functioning neither support the idea of a reduced resilience in healthy aged humans nor do they appear to strengthen assumptions derived from the so called "glucocorticoid cascade hypothesis".     

Hardiness and stress moderation: a test of proposed mechanisms

High and low hardy male and female undergraduates completed an evaluative threat task that was manipulated to influence appraisals of the task in a manner consistent with hardiness theory. High hardy subjects displayed higher frustration tolerance, appraised the task as less threatening, and responded to the task with more positive and less negative affect than did low hardy subjects. Although all subjects displayed increased heart rate (HR) in response to the experimental task, high hardy men displayed lower HR elevations during the task than did low hardy men. Hardiness did not influence HR responses among women. Manipulations of task appraisal revealed a similar pattern where men in the high hardiness appraisal conditions displayed lower levels of physiological arousal during the task than did men in the low hardiness appraisal conditions. Appraisal manipulations had either no effect or the opposite effect among women.     

Stress impairs acquisition of delay eyeblink conditioning in men and women

In rodents stress impairs delay as well as trace eyelid conditioning in females, but enhances it in males. The present study tested the effects of acute psychosocial stress exposure on classical delay eyeblink conditioning in healthy men and women. In a between subject design, participants were exposed to psychosocial stress using the Trier Social Stress Test (TSST) or a control condition which was followed by a delay eyeblink classical conditioning procedure. Stress exposure led to a significant increase in salivary cortisol and impaired acquisition of conditioned eyeblink responses (CRs). This was evident by a later first CR and an overall lower CR rate of the stress group. The stress-induced acquisition impairment was observed in both women and men. Subjects failing to show a stress-induced cortisol increase (cortisol non-responder) were not impaired in acquisition. Our findings indicate that acute stress, possibly via activation of the hypothalamus–pituitary–adrenal (HPA) axis, reduces the ability to acquire a simple conditioned motor response in humans.     

Anxiety and chronic couple relationship stress moderate adrenocortical response to couple interaction in expectant parents

The study examines whether anxiety or chronic relationship stress alter the way that couple conflict affects cortisol levels for women and men during the transition to parenthood. Saliva samples, assayed for cortisol, were collected before and after couple interaction from 128 heterosexual couples expecting their first child. Confirming prior research, expectant mothers had higher cortisol levels than their spouses, and gestational age was linked to women's cortisol level. Negativity during couple interaction was associated with greater cortisol reactivity for men, but not women. Tests of moderation indicated little relation between negativity and cortisol recovery for individuals with a low level of anxiety or little history of chronic arguing with the partner. However, among individuals with elevated levels of either of these two factors, negativity was linked to less cortisol recovery for men, but more cortisol recovery for women. Consistent results were also found for the relation between low warmth in the couple interaction and both reactivity and recovery for men and women high in anxiety. Future research should examine whether pregnancy is responsible for these different gender patterns, or whether the inhibition of negativity is stressful for women with high levels of risk.