Gender differences and the relationships of perceived background stress and psychological distress with cardiovascular responses to laboratory stressors

The primary aim of this study was to evaluate the relationships of perceived background stress and self-reported psychological distress on cardiovascular reactivity during acute laboratory stressors. The Perceived Stress Scale (PSS) was used as the measure of perceived background stress, and the General Health Questionnaire (GHQ) was used as the measure of psychological distress. A secondary aim was to examine whether background stress and psychological distress affected the susceptibility to induction of a negative mood using music. Heart rate (HR) and blood pressure (BP) were measured in 149 female and male college students at rest and during a stressful mental arithmetic (MA) task and a mood induction procedure. Higher scores on the GHQ were associated with lower systolic BP reactivity during the MA task by all participants. Higher scores on the PSS and GHQ were also associated with lower diastolic BP and HR reactivity, but only in females. Thus, higher self-reports of background stress and psychological distress tended to result in blunted reactivity to an acute laboratory challenge. Higher levels of background stress and psychological distress were not associated with greater susceptibility to a negative mood induction. This study adds to the growing literature indicating that potentially negative health outcomes may be associated with diminished cardiovascular reactivity under certain conditions.     

Physiological stress responses in defensive individuals: Age and sex matter

The association between defensiveness and physiological responses to stress were evaluated in 81 healthy working men and 118 women, aged 20 to 64 years (M=41; SD=11.45). Participants underwent laboratory testing during which they were exposed to interpersonal stressors. Heart rate (HR), heart rate variability (HRV), blood pressure (BP), and salivary cortisol were measured. Defensiveness was evaluated using the Marlowe‐Crowne Social Desirability Scale. In women, higher defensiveness was associated with greater BP and HR reactivity to stress (p<.05). In older men, lower defensiveness was associated with increased systolic BP reactivity to stress (p<.02), delayed HRV recovery (p<.02), and greater salivary cortisol levels (p<.02). In conclusion, greater defensiveness was associated with increased reactivity to stress in women whereas in older men, lower defensiveness was associated with elevated cardiovascular, autonomic, and endocrine responses to stress.     

Of larks and hearts--morningness/eveningness, heart rate variability and cardiovascular stress response at different times of day

Inter-individual differences in the circadian period of physical and mental functions can be described on the dimension of morningness/eveningness. Previous findings support the assumption that eveningness is related to greater impulsivity and susceptibility to stress than morningness. Heart rate variability (HRV) serves as a physiological correlate of self- and emotional regulation and has not yet been investigated in relation to chronotypes. The study explores differences in HRV and other cardiovascular measures in morning- and evening-types at rest and under stress at different times of day (8-11 a.m. or 4-7 p.m.). Students (N=471) were screened for chronotype and n=55 females (27 morning- and 28 evening-types) were recruited for testing. These participants performed a mental arithmetic task while heart rate (HR) and blood pressure (BP) were recorded. Spectral components and a time-domain measure of HRV were calculated on HR data from resting and mental stress periods. Evening-types had significantly higher HR and systolic BP, but lower HRV than morning-types both at baseline and during stress. Stress induced in the evening had a significantly stronger impact on absolute and baseline corrected physiological measures in both chronotypes. The interaction of chronotype and testing time did not reach the level of significance for any of the dependent variables. The enhanced physiological arousal in evening-types might contribute to increased vulnerability to psychological distress. Hence, previous behavioral findings are supported by the physiological data of this study.     

The relationship of physiological responses to the coronary-prone behavior pattern in children

Forty-one male and female children were tested for Type A (coronary-prone) behavior using the Bortner test and the MYTH questionnaire. Based on their classification as A or B, three physiological variables were compared: systolic blood pressure (SBP), heart rate (HR) (phasic, tonic, and variability), and skin conductance (SC) (magnitude and latency of responses, number of spontaneous responses) during a 3-min rest period, a 10-min unsignaled reaction time (RT), and a 10-min word task. When using the Bortner to classify groups, Type As showed a tendency toward higher SBP levels and greater SBP reactivity to tasks, and significantly greater HR levels, HR reactivity to tasks, HR variability during rest, and SCR magnitude to RT signals. When using the MYTH, Type A females showed larger increases in SBP and HR to tasks, a lower mean HR, and a faster RT. Type A males showed a higher mean HR. Thus, children classified as Type A resemble Type A adults when compared on physiological responses to stress; however, the results depend on the method used to determine Type A behavior.     

Physiologic responses to cognitive challenge during pregnancy: effects of task and repeat testing.

Physiological responses to stress during pregnancy are believed to influence birth outcomes. Researchers have studied pregnant women in laboratory stressor paradigms to investigate these associations, yet normative data on cardiovascular and respiratory responses to laboratory challenge during pregnancy are not yet established. To begin to establish such normative data, this study examined the effects of task and repeat stressor exposure on reactivity in third-trimester pregnant women. Thirty-one healthy pregnant women (mean age=27 years; range 18-36) between the 33rd and 39th week of pregnancy, were instrumented for continuous electrocardiography, blood pressure (BP), and respiration data. Subjects rested quietly for a 5-min baseline and then performed both a mental arithmetic stressor and a Stroop color-word-matching task, each 5 min in length and each followed by a 5-min recovery period. The order of the tasks was counterbalanced. After each 5-min period, subjects rated the period on a 10-point stress scale. Averaged across task type and challenge period, systolic and diastolic BP and respiration rate increased significantly in response to cognitive challenge, but heart rate (HR) did not. When data were examined for task and period effects, the following results emerged: the Stroop task elicited significantly greater systolic BP and HR reactivity than the arithmetic task, yet subjects rated the arithmetic task as more stressful. Averaged across task type, subjects showed greater systolic BP reactivity during the second challenge period compared to the first. Finally, women's BP tended to drift upward and did not return to baseline during the first recovery period. These findings indicate that averaging data across tasks and periods can obscure the time course of response patterns that may be important in the study of associations between maternal stress and perinatal development, as well as in other research on reactivity to repeat stress exposure.     

Protective effect of interval exercise on psychophysiological stress reactivity in children

Two studies determined whether interval exercise reduces children's stress reactivity. For Experiment 1 children completed interval exercise ( n =14) or watched TV ( n =14) for 25 min. After 20 min rest children completed a speech task. Speech-induced diastolic blood pressure (DBP) reactivity was dampened in the exercise group ( p <.05). For Experiment 2 children ( n =22) completed interval exercise-speech and TV-speech conditions on separate days. Physical activity was assessed by accelerometry and aerobic fitness estimated by submaximal exercise. DBP, systolic BP, and heart rate (HR) reactivity to the speech stressor were dampened ( p <.05) after exercise compared to TV watching. Fitness was positively associated with HR reactivity. Interval exercise that mimics usual patterns of physically active play dampens cardiovascular reactivity to interpersonal stress.     

Stability of individual differences in cardiovascular reactivity: A thirteen month follow-up

This study concerns the stability of individual differences in cardiovascular reactivity among nineteen male subjects who had participated in a similar investigation thirteen months earlier. In the previous study (Year I), subjects were presented a frustrating task in concept formation to perform at each of two experimental sessions, scheduled one week apart, and recordings of heart rate (HR) and systolic and diastolic blood pressure (SBP, DBP) obtained during periods of rest and task performance on each occasion of testing. Under the current procedure (Year II), subjects were exposed to the same experimental stressor as on year I, as well as a second cognitive task involving a difficult problem in “mental arithmetic”; HR, SBP and DBP were again recorded both at rest and while subjects performed the instructed tasks. Measures of task-related cardiovascular arousal across the two years of observation revealed reproducible individual differences with respect to the magnitude of subjects' HR and SBP, but not DBP, reactivity. Although individual differences in HR and SBP responses correlated positively, neither HR nor SBP reactivity covaried reliably with DBP changes. It was suggested that concomitant response differences in HR and SBP, as observed under these experimental conditions, may reflect an underlying dimension of individual differences in beta-adrenergic reactivity.     

Family history of hypertension,gender, and cardiovascular responsivity during stress

The relationships of family history of hypertension and gender to cardiovascular responses to stress were investigated in this research. One hundred twenty-three subjects were monitored while they rested and performed two tasks, reaction time and Ravens progressive matrices. Positive-family history males exhibited higher levels of systolic blood pressure than the negative male group and higher levels of rate pressure product than the positive-family history female group. Positive-family history males also had heart rate levels as high as the females. Female subjects did not differ from each other based on family history. In addition, subjects were grouped by gender and by high- or low-heart rate reactivity. The results suggest that heart rate reactivity has equally broad effects on cardiovascular function for males and females; for males, this reactivity during rests and tasks also tends to be associated with family history of hypertension.     

Parental Hypertension and Cardiovascular Response to Cognitive and Isometric Challenge

The purposes of this investigation were to contrast the cardiovascular responses of sons of hypertensive and normotensive parents to tasks involving cognitive and isometric challenge, and lo examine the relationship of individual differences in heart rate (HR) reactivity to baseline blood pressure (BP) measurements. Thirty-six male, undergraduate volunteers (18 with and 18 without a parental history of hypertension) were scheduled for two, 1-hr experimental sessions (Days I and II). On Day 1, HR and BP measurements were obtained while subjects performed each of three laboratory tasks: a difficult test in concept formation, serial subtraction, and a sustained handgrip at 30% of maximum voluntary contraction. Each task lasted 3 min and was preceded by a 3-min baseline interval. On Day II, subjects were instructed to relax quietly while baseline measures of HR and BP were recorded. Relative to sons of normotensive parents, offspring of hypertensives exhibited higher mean Systolic BPs during all task periods; no corresponding group differences were observed on either Day I or Day II baseline recordings. Unlike SBP, Diastolic BP measurements did not vary reliably by parental hypertensive/normotensive status. Although the mean HRs of sons of hypertensives were significantly higher than in offspring of normotensives, these differences obtained uniformly across both the baseline and task intervals. Among subjects identified as High HR reactors during the two cognitive tasks, sons of hypertensive parents exhibited Day II baseline SBPs about 9 mmHg higher than did subjects without a parental history of hypertension. Among subjects identified as Low HR reactors, baseline SBPs did not differ reliably between sons of hypertensive and normotensive parents.     

Frontal electrocortical and cardiovascular reactivity during happiness and anger

The present study investigated electrocortical and cardiovascular reactivity during positive and negative emotion, and examined the relation of asymmetric frontal lobe activation to cardiovascular responses. Participants were 30 healthy, right-handed university students (mean age, 23.9; 60% female; 76% Caucasian). Electroencephalographic (EEG), blood pressure (BP), and heart rate (HR) responses were assessed while subjects engaged in laboratory tasks (personally-relevant recall tasks and film clips) designed to elicit happiness or anger. Happiness-inducing tasks evoked more prominent left than right frontal EEG activation, and greater left frontal EEG activation than anger-inducing tasks. However, anger-inducing tasks were, on average, associated with comparable left and right frontal EEG activation. Irrespective of emotional valence, cardiovascular activation was more pronounced during personally-relevant recall tasks than during the viewing of film clips. During anger recall, both greater left frontal EEG response (r=-0.46, P<0.02) and greater right frontal EEG response (r=-0.45, P<0.02) were correlated significantly with increased HR reactivity during the task. In addition, a right lateralized frontal EEG response during anger-inducing tasks was associated with greater concomitant systolic BP (P<0.03) and diastolic BP (P<0.008) reactivity. Exploratory analyses also indicated that men who displayed a left lateralized frontal EEG response during happiness-inducing tasks showed the greatest concomitant systolic BP and HR reactivity (P's<0.03). These findings suggest that asymmetric frontal EEG responses to emotional arousal may elicit different patterns of cardiovascular reactivity in healthy adults.     

Reproducibility of blood pressure and heart rate reactivity: A meta-analysis

Reproducibilities of blood pressure and heart rule (HR) reactivity reported in studies assessing responses to the same laboratory stressors across occasions were reviewed with meta-analytic techniques. Changes in HR had the greatest reproducibility (r =.555), followed by systolic blood pressure (SBP) (.407) and diastolic blood pressure (DBF) (.348), Both SBP and HR response reproducibility was higher at shorter lest-retest intervals, whereas DBP values varied unsystematically with length of test-retest interval Older samples exhibited higher SBP and DBP reproducibility to stressors. SBP and DBP reproducibilities were better for tasks that did not make speech demands. The reliability of reactivity assessment was higher when based on three or more measurements, On the basis of able evidence, the drop in stress reproducibility, as test-retest interval increases, places limits on the viability of BP reactivity as a strong marker or risk factor for coronary heart disease.     

Parental Hypertension and Cardiovascular Response to Stress in Healthy Young Adults

One indicator of elevated risk for subsequent development of essential hypertension is the presence of the disorder in either or both parents. Exaggerated cardiovascular responsivity to stress has also been suggested as a possible precursor to hypertension. This study examined the relationship between parental hypertension and the heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP) levels of 103 healthy college-age men, during two resting conditions and stressful cold pressor and reaction time tasks. Sons of hypertensive parents (N = 25) showed higher HR and SBP than sons of normotensive parents (N = 78) during both rest and stress, but these differences were greatest during the stressful reaction time (RT) task. No reliable differences in DBP were seen. A subsample of 45 subjects, including 14 with hypertensive parents, were also monitored during a second stress, the cold pressor test; only trends toward HR or BP differences related to parental hypertension were seen for this stress, although HR and SBP differences during the RT task were still significant (p<.05) even in this smaller group. Since the incidence of high blood pressure is known to be greater among the offspring of hypertensive parents, these findings suggest that cardiovascular responses to certain types of stress (e.g., active coping tasks) may help predict future risk of hypertension.     

Does cardiovascular reactivity to stress measured in the laboratory generalize to thesis and dissertation meetings among doctoral students?

This study extends previous work investigating the generalizability of cardiovascular reactivity to stress obtained in response to laboratory-based tasks to cardiovascular reactivity measured in response to a naturally occurring event. Heart rate (HR) and blood pressure reactivity to stress were measured with ambulatory monitoring equipment in 6 male and 16 female healthy, White, graduate students in two settings: during five standardized stressors in the laboratory, and during the proposal or defense of a thesis or dissertation. Results indicate that for all cardiovascular parameters, the magnitude of change was greatest in response to the natural event, and that among the laboratory tasks, the greatest degree of reactivity was observed in response to a speech task. However, the cardiovascular reactivity associated with the speech task was not the best predictor of the natural speech task, despite the structural similarity of these two tasks. Overall, greater correlations were noted among all of the tasks based on absolute values of HR and blood pressure versus residualized change scores for HR and blood pressure, and greater correlations also were observed among anticipation periods than among task periods. Partial support was provided for the hypothesis that the generalizability of cardiovascular reactivity to stress would be enhanced by using multiple laboratory tasks rather than single tasks. This effect was observed for HR but not blood pressure. Consistent with the literature in this field, we observed only limited generalizability of cardiovascular response to stress from laboratory to the field. This project was supported through the grant-in-aid program of the American Heart Association’s West Virginia Affiliate (Grant 93–7854S). Portions of this article were presented at the 30th Annual Meeting of the Association for the Advancement of Behavior Therapy in November 1996 and at the 20th Annual Meeting of the Society for Behavioral Medicine in March 1999.     

Excess heart rate and systolic blood pressure during psychological stress in relation to metabolic demand in adolescents

Cardiovascular responses during exercise are matched to the increased metabolic demand, but this may not be the case during psychological stress. No studies to date have tested this hypothesis in youth. Fifty-four youth, ages 13-16 years completed two visits. Heart rate (HR), systolic blood pressure (SBP), and oxygen (O(2)) consumption were measured during a graded exercise test on one day and during psychological stress reactivity (star tracing, speech) on another day. Predicted HR and SBP values during psychological stress were calculated based on HR-O(2) and SBP-O(2) relationships calculated during graded exercise. At a given O(2) consumption, actual HR was greater (p<0.02) than predicted for all stress tasks. Actual SBP was greater (p<0.001) than predicted for all stress tasks. This was the first study to demonstrate that cardiovascular responses were in excess of what would be expected based on metabolic demand in youth.     

The impact of physical proximity and attachment working models on cardiovascular reactivity: Comparing mental activation and romantic partner presence

Close relationships, especially high‐quality romantic relationships, are consistently associated with positive physical health outcomes. Attenuated cardiovascular reactivity is one physiological mechanism implicated in explaining these effects. Drawing on attachment and social baseline theories, this experimental study evaluated two potential affiliative cues as mechanisms through which romantic relationships may attenuate cardiovascular reactivity to a laboratory‐based stressor. Prior to a cold pressor task, 102 participants were randomly assigned to either have their partner physically present, call upon a mental representation of their partner, or think about their day during the stressor. Consistent with our preregistered hypotheses, participants in both the partner present and mental activation conditions had significantly lower blood pressure (BP) reactivity during the cold pressor task compared to control participants for both systolic (d = ?0.54) and diastolic BP (d = ?0.53), but no significant differences emerged for heart rate or heart rate variability. Although participants in the partner present and mental activation conditions had similar BP reactivity to the cold pressor task, those in the partner present condition reported significantly less pain as a result of the task. The difference in BP reactivity by condition was moderated—BP reactivity was greater for people with lower self‐reported relationship satisfaction. The results suggest that accessing the mental representation of a romantic partner and a partner’s presence each buffer against exaggerated acute stress responses to a similar degree.     

Stability of individual differences in cardiovascular reactivity

Examining the stability of individual differences in cardiovascular reactivity, 42 male subjects were presented a difficult cognitive task to perform at each of two experimental sessions, scheduled 1 week apart, and recordings of hear rate and systolic and diastolic blood pressure obtained during periods of rest and task performance on each occasion of testing. Measures of task-related arousal (reactivity) across the two experimental sessions revealed substantial and reliable individual differences on all three response variables, as evidenced by (1) subsets of subjects representing clearly differentiated groups of Reactors and NonReactors on each measure and (2) correlation of reactivity scores of all subjects between the first and second sessions. While individual differences in systolic blood pressure and heart rate reactivity correlated positively, magnitude of systolic and diastolic blood pressure responses did not covary reliably among subjects. It was concluded that the present data demonstrate consistency, or reproducibility, of idiosyncratic cardiovascular reactivity and suggested that the variability of relationships among response measures may reflect more basic dimensions of individual differences involving neuroregulatory mechanisms underlying cardiovascular adjustments.     

Features of autonomic cardiovascular control during cognition in major depressive disorder

Previous research has suggested reduced parasympathetic cardiac regulation during cognitive activity in major depressive disorder (MDD). However, little is known about possible abnormalities in sympathetic control and cardiovascular reactivity. This study aimed to provide a comprehensive analysis of autonomic cardiovascular control in the context of executive functions in MDD. Thirty six MDD patients and 39 healthy controls participated. Parameters of sympathetic (pre‐ejection period, PEP) and parasympathetic control (high and low frequency heart rate variability, HF HRV, LF HRV; and baroreflex sensitivity, BRS) as well as RR interval were obtained at rest and during performance of executive function tasks (number‐letter task, n‐back task, continuous performance test, and Stroop task). Patients, as compared to controls, exhibited lower HF HRV and LF HRV during task execution and smaller shortenings in PEP and RR interval between baseline and tasks. They displayed longer reaction times during all conditions of the tasks and more omission errors and false alarms on the continuous performance test. In the total sample, on‐task HF HRV, LF HRV and BRS, and reactivity in HF HRV, LF HRV, and PEP, were positively associated with task performance. As performance reduction arose independent of executive function load of the tasks, the behavioral results reflect impairments in attention and processing speed rather than executive dysfunctions in MDD. Abnormalities in cardiovascular control during cognition in MDD appear to involve both divisions of the autonomic nervous system. Low tonic parasympathetic control and blunted sympathetic reactivity imply reduced physiological adjustment resources and, by extension, provide suboptimal conditions for cognitive performance.     

Blunted cardiovascular responses to acute psychological stress predict low behavioral but not self‐reported perseverance

Emerging evidence relates attenuated physiological stress reactions to poor behavioral regulation. However, only a small number of behaviors such as impulsivity and risk taking have been explored. Nevertheless, one opportunistic study suggested that blunted reactivity might relate to poor perseverance. The present study examined the relationship between cardiovascular reactivity to acute active psychological stress and self‐reported and behavioral perseverance. Participants (N = 64) completed a self‐report perseverance questionnaire before heart rate (HR) and blood pressure (BP) were measured at rest and in response to 4‐min active (paced auditory serial addition; PASAT) and passive (cold pressor) stress tests. This was followed by an unsolvable Euler puzzle tracing task, with the time spent and number of attempts endeavoring to solve the puzzle recorded as behavioral perseverance measures. Blunted systolic and diastolic BP reactivity to the PASAT was associated with fewer attempts at the impossible puzzle, and lower diastolic BP PASAT reactivity related to less time persevering at the puzzle. Moreover, attenuated diastolic BP and HR PASAT reactivity predicted poorer perseverance at keeping one's hand in the iced water of the cold pressor task. There was no association between reactivity and self‐reported perseverance. These preliminary findings add to the evidence that implicates blunted reactivity as a physiological marker of poor behavioral regulation, and this may indicate why individuals with blunted reactivity are at increased risk of developing negative health outcomes (e.g., obesity and addictions).     

Heart rate variability in acute psychosis

Heart rate variability (HRV) provides reliable tools to assess the integrity and reactivity of autonomic nervous function. Our aim was to examine HRV in the resting condition and during different mental loads in acute psychosis compared to healthy controls. HRV was measured in 17 first-episode drug-naive patients with psychosis and 21 healthy controls during oddball tasks and while performing the Wisconsin Card Sorting Test. A discrete event series was constructed by an adaptive QRS detector algorithm and power spectrum estimation was carried out. The RMSSD (representing interval differences of successive heartbeats) and the amount of high frequency (HF) power were significantly reduced in patients. Moreover, the patients' HRV remained unaltered during the tasks, whereas in controls the HRV diminished with increasing mental load of the task. Patients with psychosis displayed less short-term HR reactivity than healthy controls. They also failed to adapt HRV according to the task-connected strain. Acute psychosis is characterized by a limited capacity to respond to external demands at the level of autonomic nervous system.     

Ethnic differences in cardiovascular responses to laboratory stress: A comparison between asian and white americans

Compared to other ethnic groups, Asian Americans show significantly lower rates of cardiovascular disease (CVD). We tested the hypothesis that Asian Americans would show reduced cardiovascular responses to laboratory stressors than Caucasians. Forty-three Asians (18 men, 25 women) and 77 Caucasians (36 men, 41 women) with a mean age of 24 years (SD = 3.93) participated in a stress reactivity protocol consisting of four tasks (speech, serial subtraction, mirror tracing, handgrip) while heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured. Asian Americans demonstrated overall lower reactivity across tasks for SBP F(1,117 = 7.48, p < .01) and a trend toward lower HR response F(1,117 = 3.18, p < .10). A significant ethnicity by task interaction was observed for HR reactivity F(3,351 = 2.94, p < .05) such that Caucasians showed greater responses for the subtraction task.