Prediction of resting cardiovascular functioning in youth with family histories of essential hypertension: a 5-year follow-up

Blunted cardiovascular reactivity to psychological stress and prospective health: a systematic review

Novel research demonstrates that lower or 'blunted' cardiovascular reactions to stress are associated with a range of adverse outcomes. The aim of the current review was (1) to examine the prospective outcomes predicted by blunted cardiovascular reactivity and (2) to identify a range of blunted cardiovascular reaction levels that predict these outcomes. Electronic databases were systematically searched (Medline, PsycArticles, PsycInfo, CINAHL, PubMed, Web of Science). Studies were included if they examined the prospective influence of blunted cardiovascular reactivity to psychological stress (SBP, DBP or HR) on a negative health, behavioural or psychological outcome. A total of 23 studies were included in the review. Blunted reactivity predicted (1) adverse cardiovascular health, primarily in cardiac samples (e.g., myocardial infarction, carotid atherosclerosis) and (2) outcomes associated with motivational and behavioural dysregulation in healthy samples (e.g., obesity, smoking addiction, depression). The cardiovascular reactivity threshold levels that were predictive of adverse health outcomes ranged between -3.00-12.59 bpm (14.41% to 136.59% lower than the sample mean) and -2.4-5.00 mmhg (65.99% to 133.80% lower than sample mean), for HR and DBP respectively. We posit that blunted reactions lower than, or equal to, the ranges reported here may be utilised by clinicians and researchers to identify individuals who are at increased risk of adverse cardiovascular health outcomes, as well as outcomes associated with motivational and behavioural dysregulation.

Cardiovascular Stress Reactivity and Health: Recent Questions and Future Directions

OBJECTIVE

High cardiovascular reactions to psychological stress are associated with the development of hypertension, systemic atherosclerosis, and cardiovascular disease. However, it has become apparent that low biological stress reactivity also may have serious consequences for health, although less is known about the mechanisms of this. The objectives of this narrative review and opinion article are to summarize and consider where we are now in terms of the usefulness of the reactivity hypothesis and reactivity research, given that both ends of the reactivity spectrum seem to be associated with poor health, and to address some of the key criticisms and future challenges for the research area.

METHODS

This review is authored by the members of a panel discussion held at the American Psychosomatic Society meeting in 2019, which included questions such as the following: How do we measure high and low reactivity? Can high reactivity ever indicate better health? Does low or blunted reactivity simply reflect less effort on task challenges? Where does low reactivity originate from, and what is a low reactor?

RESULTS

Cardiovascular (and cortisol) stress reactivity are used as a model to demonstrate an increased understanding of the different individual pathways from stress responses to health/disease and show the challenges of how to understand and best use the reconstruction of the long-standing reactivity hypothesis given recent data.

CONCLUSIONS

This discussion elucidates the gaps in knowledge and key research issues that still remain to be addressed in this field, and that systematic reviews and meta-analyses continue to be required.

Openness to experience and stress responsivity: An examination of cardiovascular and underlying hemodynamic trajectories within an acute stress exposure

The personality trait openness to experience has been implicated in health, and in particular cardiovascular wellbeing. In a sample of 62 healthy young female adults, the role of openness in cardiovascular responsivity during a stress exposure was examined. Traditionally, methodologies have averaged a stress exposure into a single reading. This may be limited in that it does not consider patterns of cardiovascular adaptation within a stress exposure. Continuous cardiovascular data were reduced to mean 10 second readings, with phases determined through examinations of shifts in responsivity between each 10 second pairing. Analyses revealed a significant linear interaction for openness across the entire exposure for systolic blood pressure, and cardiac output. A significant between-subjects effect for heart rate also emerged. Contrary to their lower counterparts, those highest in openness exhibited an increasingly myocardial hemodynamic response profile throughout the exposure. Comparisons of responsivity suggests adaptive stress response trajectories for those highest in openness. This study also provides evidence that an attenuation of myocardial responsivity may underpin blunted responsivity. This study provides a potential mechanism in reported openness-health associations.

Do Cardiovascular Responses to Active and Passive Coping Tasks predict Future Blood Pressure over a 10-Month Later?

The study examined whether cardiovascular responses to active or passive coping tasks and single or multiple tasks predicted changes in resting blood pressure (BP) over a ten-month period. Heart rate (HR), BP, cardiac output (CO), and total peripheral resistance (TPR) were measured at rest, and during mental stress tests (mental arithmetic, speech, and cold pressor tasks). A total of 104 eligible participants participated in the initial study, and 77 (74.04%) normotensive adult participants’ resting BP were re-evaluated at ten-month follow-up. Regression analyses indicated that after adjustment for baseline BP, initial age, gender, body mass index, family history of cardiovascular disease, and current cigarette smoking, heighted systolic blood pressure (SBP) and HR responses to an active coping task (mental arithmetic) were associated with increased future SBP (ΔR2 = .060, ΔR2 = .045, respectively). Further, aggregated SBP responsivity (over the three tasks) to the predictor models resulted in significant, but smaller increases in ΔR2 accounting for .040 of the variance of follow-up SBP. These findings suggest that cardiovascular responses to active coping tasks predict future SBP. Further, compared with single tasks, the findings revealed that SBP responses to three tasks were less predictive compared to an individual task (i.e., mental arithmetic). Of importance, hemodynamic reactivity (namely CO and TPR) did not predict future BP suggesting that more general psychophysiological processes (e.g., inflammation, platelet aggregation) may be implicated, or that BP, but not hemodynamic reactivity may be a marker of hypertension.

Novel mechanism within the paraventricular nucleus reduces both blood pressure and hypothalamic pituitary-adrenal axis responses to acute stress

Macrophage migration inhibitory factor (MIF) counteracts pressor effects of angiotensin II (ANG II) in the paraventricular nucleus of the hypothalamus (PVN) in normotensive rats, but this mechanism is absent in spontaneously hypertensive rats (SHRs) due to a lack of MIF in PVN neurons. Since endogenous ANG II in the PVN modulates stress reactivity, we tested the hypothesis that replacement of MIF in PVN neurons would reduce baseline blood pressure and inhibit stress-induced increases in blood pressure and plasma corticosterone in adult male SHRs. Radiotelemetry transmitters were implanted to measure blood pressure, and then an adeno-associated viral vector expressing either enhanced green fluorescent protein (GFP) or MIF was injected bilaterally into the PVN. Cardiovascular responses to a 15-min water stress (1-cm deep, 25°C) and a 60-min restraint stress were evaluated 3-4 wk later. MIF treatment in the PVN attenuated average restraint-induced increases in blood pressure (37.4 ± 2.0 and 27.6 ± 3.5 mmHg in GFP and MIF groups, respectively, P < 0.05) and corticosterone (42 ± 2 and 36 ± 3 μg/dl in GFP and MIF groups, respectively, P < 0.05). MIF treatment in the PVN also reduced stress-induced elevations in the number of c-Fos-positive cells in the rostral ventrolateral medulla (71 ± 5 in GFP and 47 ± 5 in MIF SHRs, P < 0.01) and corticotropin-releasing factor mRNA expression in the PVN. However, MIF had no significant effects on the cardiovascular responses to water stress in SHRs or to either stress in Sprague-Dawley rats. Therefore, viral vector-mediated restoration of MIF in PVN neurons of SHRs attenuates blood pressure and hypothalamic pituitary adrenal axis responses to stress.

Integrative commentary: implications of blunted reactivity

The previous issue of the International Journal of Psychophysiology was a special issue that collected some of the latest emerging evidence on blunted reactivity and its relationships with a variety of negative health outcomes. This commentary on the special issue briefly reviews each of the contributions and then provides some thoughts on the general themes that run through these papers. The findings from the special issue suggest that both lower and higher than expected cardiovascular and neuroendocrine responses to active psychological challenges may be maladaptive and differentially associated with adverse health sequelae.

Blood pressure reactions to acute mental stress and future blood pressure status: data from the 12-year follow-up of the West of Scotland Study

OBJECTIVE

To test the reactivity hypothesis using blood pressure data collected 12 years after baseline. This study examined whether blood pressure reactions to acute mental stress predicted future blood pressure resting levels, as well as the temporal drift in resting blood pressure, and whether the prediction was affected by sex, age, and socioeconomic status.

METHODS

Resting blood pressure was recorded at an initial baseline and in response to a mental stress task. Twelve years later, resting blood pressure was again assessed. Data were available for 1196 participants (645 women, 551 men), comprising, at the time of stress testing, 439 who were aged 24 years; 503, aged 44; and 254, aged 63. The participants included 531 who were from manual occupational households and 661 from nonmanual occupational households.

RESULTS

In multivariate linear regression models, adjusting for a number of potential confounders, systolic blood pressure (SBP) reactivity positively predicted future resting SBP, as well as the upward drift in SBP over the 12 years (β = 0.10, p < .001 in both cases). The effect sizes were smaller than those reported from an earlier 5-year follow-up. The analogous associations for diastolic blood pressure reactivity were not statistically significant. In multivariate logistic regression, high SBP reactivity was associated with an increased risk of being hypertensive 12 years later (odds ratio = 1.03, 95% confidence interval = 1.01-1.04, p < .001).

CONCLUSIONS

The present findings that greater reactivity is associated with higher future resting blood pressure, more upward drift in resting blood pressure, and future hypertension provide support for the reactivity hypothesis.

Prenatal and early childhood blood lead levels and cardiovascular functioning in 9(1/2) year old children

A number of studies have found that increasing lead exposure is associated with increases in blood pressure in humans. Studies with animals suggest that lead-induced increases in vascular resistance account for these increases in blood pressure. The present study assessed cardiovascular functioning at rest and in response to acute stress for 9(1/2) year old children (N=122) having relatively low prenatal (cord) blood lead levels (M=1.98 microg/dL, SD=1.75) and low postnatal (early childhood) blood lead levels (M=4.62 microg/dL, SD=2.51). Higher cord blood levels were associated with higher baseline systolic blood pressure (SBP), and higher early childhood lead levels were associated with greater total peripheral (vascular) resistance (TPR) responses to acute stress. In addition, a negative association between blood lead levels and stroke volume (SV) suggests that lead-induced increases in vascular resistance were sufficient to produce cardiac afterload, a situation arising when blood pressure in the aorta makes it difficult for the left ventricle to eject blood. These effects were not mediated by differences in task performance or emotional responses to the acute stress tasks. Finally, these effects were significant for lead levels considered low, notably, below the 10 microg/dL threshold currently adopted by the CDC for deleterious effects.

Unfair treatment, discrimination, and ambulatory blood pressure in black and white adolescents

The authors tested the hypotheses that unfair treatment and its attribution to race, physical appearance, and peer group were related to elevated ambulatory blood pressure (ABP). During 2 school days, 207 Black and White adolescents wore an ABP monitor and answered questions about mood, posture, location, and activity level at the time of the ABP assessment. At a separate session, in-clinic resting blood pressure and perceptions of unfair treatment were measured. Multilevel mixed models showed that unfair treatment and its attribution to race were not associated with ABP. However, adolescents who indicated that the primary reason for unfair treatment was their physical appearance had elevated ABP. Feeling unfairly treated because of physical appearance may impact blood pressure uniquely during the adolescent transition.

Life events and hemodynamic stress reactivity in the middle-aged and elderly

Recent versions of the reactivity hypothesis, which consider it to be the product of stress exposure and exaggerated hemodynamic reactions to stress that confers cardiovascular disease risk, assume that reactivity is independent of the experience of stressful life events. This assumption was tested in two substantial cohorts, one middle-aged and one elderly. Participants had to indicate from a list of major stressful life events up to six they had experienced in the previous 2 years. They were also asked to rate how disruptive and stressful they were, at the time of occurrence and now. Blood pressure and pulse rate were measured at rest and in response to acute mental stress. Those who rated the events as highly disruptive at the time of exposure and now exhibited blunted systolic blood pressure reactions to acute stress. The present results suggest that acute stress reactivity may not be independent of stressful life events experience.

Blood pressure reactivity to psychological stress predicts hypertension in the CARDIA study

BACKGROUND

A longstanding but controversial hypothesis is that individuals who exhibit frequent, large increases in blood pressure (BP) during psychological stress are at risk for developing essential hypertension. We tested whether BP changes during psychological stress predict incident hypertension in young adults.

METHODS AND RESULTS

We used survival analysis to predict hypertensive status during 13 years of follow-up in a sample of >4100 normotensive black and white men and women (age at entry, 18 to 30 years) enrolled in the CARDIA study. BP responses to 3 psychological challenges--cold pressor, star tracing, and video game tasks--were measured. Hypertensive status was defined as use of antihypertensive medication or measured BP > or =140/90 mm Hg. After adjustment for race, gender, covariates (education, body mass index, age, and resting pressure), and their significant interactions, the larger the BP responses were to each of the 3 tasks, the earlier hypertension occurred (P<0.0001 to <0.01). The systolic BP effect for the cold pressor task was apparent for women and for whites in race- and gender-specific models, whereas the diastolic BP effect for the video game was apparent for men.

CONCLUSIONS

Young adults who show a large BP response to psychological stress may be at risk for hypertension as they approach midlife.

Blood pressure reactions to stress and the prediction of future blood pressure: effects of sex, age, and socioeconomic position

OBJECTIVE

This epidemiological study examined whether the magnitude of blood pressure reactions to mental stress was associated with future blood pressure and whether the strength of association was affected by sex, age, and socioeconomic position.

MATERIALS AND METHODS

Resting blood pressure was recorded at initial baseline and in response to mental stress. Five-year follow-up resting blood pressure data were available for 990 (68%) of the participants; 333 were 23 years old at the time of stress testing, 427 were 43, and 230 were 63. There were 541 women and 449 men; 440 came from manual and 550 from nonmanual occupation households.

RESULTS

Systolic blood pressure reactions to stress correlated positively with follow-up systolic blood pressure; no association was found for diastolic blood pressure reactions and follow-up diastolic blood pressure. In multivariate tests, systolic reactivity remained predictive of follow-up systolic blood pressure and accounted for 2.3% of the variance not explained by age, body mass index, and initial baseline systolic blood pressure. Systolic and diastolic reactivity predicted 5-year upward drift in systolic and diastolic blood pressure respectively, accounting for an additional 3.6% and 2.9% of variance, respectively, in multivariate models. The predictive value of reactivity was greater for participants from manual occupation households and tended to be greater for men.

CONCLUSIONS

The results of this study indicate that blood reactions to mental stress predict future blood pressure status and the increase in resting blood pressure over time. The magnitude of the prediction appears to vary with socioeconomic position and sex.

Cardiovascular reactivity to stress predicts future blood pressure in adolescence

OBJECTIVE

This study evaluated the prospective relationship between cardiovascular reactivity to psychological stress and increases in resting blood pressure across a 3-year period among a multiethnic pediatric sample (N = 149).

METHODS

Systolic and diastolic blood pressure; EKG heart rate, pre-ejection period, and mean successive difference of R to R intervals; and impedance-derived measures of cardiac output, stroke volume, and total peripheral resistance were collected during performance of four tasks that elicited different hemodynamic response patterns. Changes from baseline to each task were standardized and averaged to form eight composite scores. Analyses adjusted for time 1 baseline blood pressure and age, body mass index at baseline and change to follow-up, and duration of follow-up.

RESULTS

Rises in SBP over the follow-up period were independently predicted by SBP (beta = 0.161, p =.009), DBP (beta = 0.132, p =.02), and CO (beta = 0.144, p =.02) composite measures of reactivity. Rises in DBP over the follow-up period were predicted by DBP (beta = 0.292, p =.003, respectively), and MSD (beta = -0.176, p <.03) composite measures of reactivity. TPR reactivity was not related prospectively to blood pressure rises.

CONCLUSIONS

This study adds to the pediatric literature documenting an association between cardiovascular reactivity to stress and subsequent risk for hypertension. It is the first to show that impedance-derived measures of myocardial function during stress are related to future blood pressure levels.

Relationships among socioeconomic status, stress induced changes in cortisol, and blood pressure in African American males

The inverse relation between socioeconomic status (SES) and cardiovascular disease (CVD) risk has been posited to be partially due to exaggerated cardiovascular reactivity (CVR) to stress. Stress elicits hypothalamic-pituitary-adrenal axis activation (e.g., increased cortisol secretion), which may contribute to subsequent blood pressure (BP) elevation. Univariate associations among SES, cortisol secretion, and aggregated change scores to stressors (i.e., video game and forehead cold) for systolic BP (SBP) and diastolic BP (DBP) were assessed in a sample of 24 African American males (M age = 18.8, +/- 2.7 years). Circadian variability of cortisol level was taken into account by partialling out collection time. Family SES was inversely related to initial cortisol level (partial r = -.46, p < .03). Neighborhood SES was inversely related to DBP reactivity (r = -.41, p < .05). The change in cortisol level during the stressor protocol was related to SBP reactivity (partial r = .44, p < .05). These results suggest that SES may be linked to CVD via BP and cortisol reactivity to stress, but prospective studies are needed to clarify whether such is the case.

Cardiovascular reactivity and development of preclinical and clinical disease states

OBJECTIVE

The objective of this review is to evaluate the evidence for the hypothesis that cardiovascular reactivity can predict the development of preclinical (elevated blood pressure, ventricular remodeling, carotid atherosclerosis) and/or clinical cardiovascular disease states.

METHODS

A review of the literature was conducted examining prospective studies.

RESULTS

Three large epidemiological studies with long-term follow-up periods (20 years or more) have found blood pressure responses to the cold pressor task to be predictive of subsequent essential hypertension in initially normotensive samples. Studies showing less consistent results have tended to use shorter-term follow-up periods. A larger body of literature demonstrates consistent associations between stress-related cardiovascular reactivity and blood pressure elevations in youth over the course of 1 to 6 years; such relationships have not been consistently shown among adult samples. Moderately consistent evidence points to a positive relationship between reactivity and other measures of subclinical disease (increased left ventricular mass and carotid atherosclerosis) among the few prospective studies that have examined these issues to date. A number of additional factors, however, such as baseline levels of disease risk and exposure to psychosocial stress, seem to moderate these relationships. Health status at baseline also seems to moderate the association between reactivity and clinical coronary heart disease in recent reports: two of three existing studies in initially healthy samples show no evidence of a relationship between reactivity and clinical outcomes, whereas three of four studies in samples with preexisting coronary heart disease or essential hypertension show a positive relationship between reactivity and subsequent disease states.

CONCLUSIONS

There is reasonable evidence to suggest that cardiovascular reactivity can predict the development of some preclinical states (eg, increased left ventricular mass and blood pressure) states and perhaps even new clinical events in some patients with essential hypertension or coronary heart disease. However, much more information is needed concerning moderating and potentially confounding variables before the robustness of the positive relationships can become clinically useful.

Impact of Transcendental Meditation on cardiovascular function at rest and during acute stress in adolescents with high normal blood pressure

OBJECTIVE

This study examined the impact of the Transcendental Meditation (TM) program on cardiovascular (CV) reactivity in adolescents with high normal BP.

METHOD

Thirty-five adolescents [34 African Americans (AAs), 1 Caucasian American (CA); ages 15-18 years] with resting systolic blood pressure (SBP) between the 85th and 95th percentile for their age and gender on three consecutive occasions, were randomly assigned to either TM (n=17) or health education control (CTL, n=18) groups. The TM group engaged in 15-min meditation twice each day for 2 months including sessions during school lunch break. Primary CV outcome measures were changes in blood pressure (BP), heart rate (HR), and cardiac output (CO) at rest and in response to two laboratory stressors, a simulated car driving stressor and an interpersonal social stressor interview.

RESULTS

The TM group exhibited greater decreases in resting SBP (P<.03) from pre- to postintervention, compared to the CTL group. The TM group exhibited greater decreases from pre- to postintervention in SBP, HR, and CO reactivity (P's<.03) to the simulated car driving stressor, and in SBP reactivity (P<.03) to the social stressor interview.

CONCLUSION

The TM program appears to have a beneficial impact upon CV functioning at rest and during acute laboratory stress in adolescents at-risk for hypertension.

Blood pressure reactions to acute psychological stress and future blood pressure status: a 10-year follow-up of men in the Whitehall II study

OBJECTIVE

The aim of this study was to examine whether blood pressure reactions to mental stress predicted future blood pressure and hypertension.

METHODS

Blood pressure was recorded at an initial medical screening examination after which blood pressure reactions to a mental stress task were determined. A follow-up screening assessment of blood pressure and antihypertensive medication status was undertaken 10 years later. Data were available for 796 male public servants, between 35 and 55 years of age upon entry to the study.

RESULTS

Systolic blood pressure reactions to mental stress were positively correlated with follow-up screening systolic blood pressure and to a lesser extent, follow-up diastolic pressure. In multivariate tests, by far the strongest predictors of follow-up blood pressures were initial screening blood pressures. In the case of follow-up systolic blood pressure, systolic reactions to stress emerged as an additional predictor of follow-up systolic blood pressure. With regard to follow-up diastolic blood pressure, reactivity did not enter the analogous equations. The same outcomes emerged when the analyses were adjusted for medication status. When hypertension at 10-year follow-up was the focus, both systolic and diastolic reactions to stress were predictive. However, with correction for age and initial screening blood pressure, these associations were no longer statistically significant.

CONCLUSIONS

The results of this study provide modest support for the hypothesis that heightened blood pressure reactions to mental stress contribute to the development of high blood pressure. At the same time, they question the clinical utility of stress testing as a prognostic device.

The effects of life events on cardiovascular reactivity to behavioral stressors as a function of socioeconomic status, ethnicity, and sex

OBJECTIVE

The purposes of this study were 1) to examine the effects of stressful life events on cardiovascular reactivity to acute laboratory stressors in youth and 2) to determine whether these effects varied as a function of socioeconomic status, ethnicity, and/or sex.

METHODS

Four hundred eighty-three youths (mean age = 16.7 years; 249 Caucasian Americans [126 males, 123 females] and 234 African Americans [109 males, 125 females]) completed the Adolescent Resources Challenge Scale (ARCS), a measure of stressful life events, and underwent two laboratory stressors (a car-driving simulation and the Social Competence Interview) during which blood pressure, heart rate, cardiac output, and total peripheral resistance were assessed.

RESULTS

Youths who reported high levels of stressful life events showed smaller increases in blood pressure (both systolic and diastolic) and heart rate to the car-driving simulation but larger increases in cardiac output in response to the Social Competence Interview than did youths who reported low levels of stressful life events. The effect of stressful life events on cardiovascular reactivity was not moderated by sex, ethnicity, or socioeconomic status. Higher family socioeconomic status was associated with greater blood pressure, heart rate, and cardiac output increases in response to the Social Competence Interview.

CONCLUSIONS

The attenuating effects of stressful life events on cardiovascular reactivity in response to car-driving simulation in youths are consistent with an inoculation effect, whereas the potentiating impact of stressful life events on reactivity observed during the social stressor interview is compatible with a possible cost of coping effect.

High stress responsivity predicts later blood pressure only in combination with positive family history and high life stress

High cardiovascular responsivity to stressors has not consistently improved prediction of later blood pressure increases beyond the predictive effects of baseline pressure. Animal models suggest that genetic susceptibility to hypertension and frequent stress exposure are important modulating factors in stress-related hypertension. Thus in 103 men originally tested at age 18 to 22 years and reassessed 10 years later, interactive effects of genetic susceptibility (defined as 1 or more hypertensive parents) with high stress responsivity (defined as top 25% on the basis of blood pressure and cardiac responses during both reaction time and cold pressor tasks) were examined in relation to follow-up systolic and diastolic levels and to change in blood pressure status from normal (diastolic<80 mm Hg) to marginally elevated (diastolic 85 to 95 mm Hg). Men with the combination of high stress response and hypertensive parents demonstrated higher systolic (P<0.05) and diastolic levels (P<0.05) at follow-up, and they showed a 7-fold increase (7.5, 95% confidence intervals 2.3, 24.3; P<0.001) in relative risk of change in blood pressure status versus men with no family history and a 3-fold increase (3.8, confidence intervals 1.5, 9.6; P<0.004) versus less stress-responsive men who also had hypertensive parents. In 65 men who also provided ratings of daily stress, family historyxstress responsivityxdaily stress interactions were significant in predicting follow-up systolic and diastolic levels (P<0.006 and 0.03, respectively), with highest pressure levels seen when high life stress was reported by high stress responders and/or men with hypertensive parents. In conclusion, results suggest that stress responsivity as a long-term predictor is modulated by both genetic and environmental factors.