Aging or disease? Cardiovascular reactivity in Finnish men over the middle years

Effects of examination-induced stress on memory and blood pressure

Stress has been defined in many ways as a state of psychological arousal that results when the external demand is beyond what one can cope with. Stress is caused by various factors called stressors. Medical students are subjected to different kinds of stressors, such as pressure of academics with obligation to succeed, an uncertain future and difficulties of integrating into the system and different teaching protocols, which may affect their learning ability and performance. Stress has a great impact on brain mainly in the form of impaired memory and on cardiovascular function in the form of increased heart rate and blood pressure. The study was planned to assess the effects of examination induced stress on memory and blood pressure. The study was longitudinal in nature conducted at Department of Physiology, Santosh Medical College, Ghaziabad, India. Initially 100 subjects were selected from 17-24 years of age group then all the subjects were divided into two groups of 'slow-learners' and 'fast-learners' based upon their past academic performances. Readings were taken at two stages of academic year, 05 months before pre-prof examination and 03 days before pre-prof examination. Blood Pressure were measured and the memory assessments were done by using 10 subtests of PGI memory scale. We found a significant increase in stress level 3 days before the examination, compared to 5 months before the examination which in turn affected both blood pressure and memory functions. But, slow-learners were affected more compared to fast-learners.

Ambulatory Blood Pressure Reactivity as a Moderator in the Association Between Daily Life Psychosocial Stress and Carotid Artery Atherosclerosis

OBJECTIVE

We examined whether associations between daily psychosocial stressor exposures and carotid artery intima-medial thickness (IMT) may be stronger among those showing larger stress-related cardiovascular reactivity (CVR) during the course of daily living.

METHODS

A total of 474 healthy working adults (ages 30-54 years) collected ambulatory blood pressure and recorded their daily experiences, using electronic diaries, during two 2-day periods for a week. Measures of mean momentary task strain and social conflict were used as indices of stressor exposure, and partial regression coefficients linking momentary strain and conflict with ambulatory blood pressure fluctuations were used as measures of CVR. IMT was assessed in the carotid arteries using B-mode ultrasound.

RESULTS

After covariate adjustment, associations between mean task strain exposure and IMT were significant among those high in CVR to strain (for systolic blood pressure, p = .006, for diastolic blood pressure, p = .011) but not among those low in strain CVR. Similarly, associations involving mean conflict exposure were significant among those high in CVR to social conflict (p < .001 for systolic blood pressure, p = .001 for diastolic blood pressure) but not among low social conflict reactors. Significant moderation effects were more consistently shown for task strain than for social conflict, but the overall pattern of results was robust across two different types of statistical modeling procedures.

CONCLUSIONS

Individual differences in CVR may moderate the effects of daily psychosocial stress on subclinical CVD among healthy employed adults. Using ecological momentary assessment to measure stress exposure as well as stress reactivity may facilitate our ability to detect these effects.

Effects of Religious Orientation and Gender on Cardiovascular Reactivity Among Older Adults

Recent attention has focused on the relationship between religiosity and health. Although many pathways have been proposed to account for this relationship, little empirical research has investigated specific pathways in relation to specific physiological functions. This study assessed the roles that religious orientation and gender play in moderating psychophysiological reactivity to laboratory stressors among older adults. Those participants characterized by an intrinsic religious orientation (IO) demonstrated less reactivity than did those characterized by an extrinsic religious orientation. Gender did not influence reactivity. There was some evidence that the effect of religious orientation is more pronounced for interpersonal than cognitive-type stressors, although the strongest findings were evident when stressors were aggregated. The magnitude of these effects suggests that they are of practical significance. Given these results and the known relationship between reactivity and hypertension, it is proposed that IO may result in decreased risk of developing hypertension in older adults.

Exercise, Nrf2 and Antioxidant Signaling in Cardiac Aging

Aging is represented by a progressive decline in cellular functions. The age-related deformities in cardiac behaviors are the loss of cardiac myocytes through apoptosis or programmed cell death. Oxidative stress (OS) and its deleterious consequence contribute to age-related mechanical remodeling, reduced regenerative capacity, and apoptosis in cardiac tissue. The pathogenesis of OS in the elderly can predispose the heart to other cardiac complications such as atherosclerosis, hypertension, ischemic heart disease, cardiac myopathy, and so on. At the molecular level, oxidant-induced activation of Nrf2 (Nuclear erythroid-2-p45-related factor-2), a transcription factor, regulates several genes containing AREs (Antioxidant Response Element) and bring the respective translates to counteract the reactive radicals and establish homeostasis. Myriad of Nrf2 gene knockout studies in various organs such as lung, liver, kidney, brain, etc. have shown that dysregulation of Nrf2 severely affects the oxidant/ROS sensitivity and predispose the system to several pathological changes with aberrant cellular lesions. On the other hand, its gain of function chemical interventions exhibited oxidant stress resistance and cytoprotection. However, thus far, only a few investigations have shown the potential role of Nrf2 and its non-pharmacological induction in cardiac aging. Therefore, here we review the involvement of Nrf2 signaling along with its responses and ramifications on the cascade of OS under acute exercise stress (AES), moderate exercise training (MET), and endurance exercise stress (EES) conditions in the aging heart.

Older adults' hemodynamic responses to an acute emotional stressor: short report

BACKGROUND/STUDY CONTEXT: Vascular and myocardial activation can each increase blood pressure responses to stressors, but vascular responses are uniquely associated with negative affect, pernicious coping processes, and cardiovascular risk. These hemodynamic correlates of coping in response to acute stressors have not been well characterized in older adults.

METHODS

Adults 65 to 97 years of age (N = 74) either engaged in written disclosure about a distressing event (acute stressor) or wrote objectively about a neutral topic (control). Blood pressure, impedance cardiography, and affect measures were assessed at baseline and in response to writing. Moderating effects of age on affect, blood pressure, and vascular and myocardial responses to the acute stressor were tested using multiple linear regression models.

RESULTS

Follow-up tests of Age × Writing Group interactions indicated that the expected effects of written disclosure on systolic and diastolic blood pressure responses were diminished with increasing age. Regardless of age, compared with neutral writing, written disclosure increased negative affect and vascular responses, but not myocardial responses.

CONCLUSION

Blood pressure responses to an acute, emotionally evocative stressor were indistinguishable from blood pressure responses to a control condition among the eldest older adults in our sample. In contrast, characterizing the hemodynamic mechanisms of blood pressure responses revealed notable vascular effects of the acute, emotional stressor across a wide age range. Such characterization may be particularly useful for clarifying the psychophysiological pathways to older adults' cardiovascular health.

Acute exercise stress activates Nrf2/ARE signaling and promotes antioxidant mechanisms in the myocardium

Oxidative stress has been implicated in the pathogenesis of cardiovascular diseases, including myocardial hypertrophy and infarction. Although impairment of antioxidant defense mechanisms has been thought to provoke oxidative stress-induced myocardial dysfunction, it has been difficult to clearly demonstrate. Nuclear erythroid 2 p45-related factor 2 (Nrf2) is a redox-sensitive, basic leucine zipper protein that regulates the transcription of several antioxidant genes. We previously reported that sustained activation of Nrf2 upregulates transcription of a number of endogenous antioxidants in the heart. Here, we show that acute exercise stress (AES) results in activation of Nrf2/ARE (antioxidant response element) signaling and subsequent enhancement of antioxidant defense pathways in wild-type (WT) mouse hearts, while oxidative stress, along with blunted defense mechanisms, was observed in Nrf2-/- mice. We also find that AES is associated with increased trans-activation of ARE-containing genes in exercised animals when compared to age-matched sedentary WT mice. However, enhanced oxidative stress in response to AES was observed in Nrf2-/- mice due to lower basal expression and marked attenuation of the transcriptional induction of several antioxidant genes. Thus, AES induces ROS and promotes Nrf2 function, but disruption of Nrf2 increases susceptibility of the myocardium to oxidative stress. Our findings suggest the basis for a nonpharmacological approach to activate Nrf2/ARE signaling, which might be a potential therapeutic target to protect the heart from oxidative stress-induced cardiovascular complications.

Heart rate reactivity and current post-traumatic stress disorder when data are missing

AIMS

This study demonstrates that auxiliary and exclusion criteria variables increase the effectiveness of missing imputation in correcting underestimation of physiologic reactivity in relation to post-traumatic stress disorder (PTSD) caused by deleting cases with missing physiologic data.

METHODS

This study used data from survivors of the 1995 Oklahoma City bombing and imputed missing heart rate data using auxiliary and exclusion criteria variables. Logistic regression was used to examine heart rate reactivity in relation to current PTSD.

RESULTS

Of 113 survivors who participated in the bombing study's 7-year follow-up interview, 42 (37%) had missing data on heart rate reactivity due to exclusion criteria (medical illness or use of cardiovascular or psychotropic medications) or non-participation. Logistic regression results based on imputed heart rate data using exclusion criteria and auxiliary (the presence of any current PTSD arousal symptoms) variables showed that survivors with current bombing-related PTSD had significantly higher heart rates at baseline and recovered more slowly back to baseline heart rate during resting periods than survivors without current PTSD, while results based on complete cases failed to show significant correlations between current PTSD and heart rates at any assessment points.

CONCLUSIONS

Suggested methods yielded an otherwise undetectable link between physiology and current PTSD.

Intraindividual change and variability in daily stress processes: findings from two measurement-burst diary studies

There is little longitudinal information on aging-related changes in emotional responses to negative events. In the present article, we examined intraindividual change and variability in the within-person coupling of daily stress and negative affect using data from 2 measurement-burst daily diary studies. Three main findings emerged. First, average reactivity to daily stress increased longitudinally, and this increase was evident across most of the adult lifespan. Second, individual differences in emotional reactivity to daily stress exhibited long-term temporal stability, but this stability was greatest in midlife and decreased in old age. Third, reactivity to daily stress varied reliably within-persons (across-time), with individuals exhibiting higher levels of reactivity during times when reporting high levels of global subject stress in the previous month. Taken together, the present results emphasize the importance of modeling dynamic psychosocial and aging processes that operate across different time scales for understanding age-related changes in daily stress processes.

Are older adults less or more physiologically reactive? A meta-analysis of age-related differences in cardiovascular reactivity to laboratory tasks

In this meta-analytic review of 31 laboratory studies, we examined if relatively older adults showed lower or higher cardiovascular reactivity compared with relatively younger adults. Results revealed that age was associated with lower heart rate reactivity but higher systolic blood pressure (SBP) reactivity during emotionally evocative tasks. Consistent with the predictions of dynamic integration theory, the result for SBP was moderated by the degree of task activation. These data are discussed in light of existing self-regulatory models and important future research directions.

Cardiac vagal activity during psychological stress varies with social functioning in older women

The polyvagal theory states that social behavior is linked to cardiac vagal control. This theory has been tested widely in infants and children, but less so in adults. Thus, we examined if resting or stress-related changes in high-frequency heart rate variability (HF-HRV; a presumed index of vagal control) varied with social functioning in 50 healthy women (mean age 68 years). After completing assessments of social functioning, women were exposed to laboratory stressors with concurrent psychophysiological monitoring. Although stressor-induced suppression of HF-HRV was common, women with less stressor-induced suppression of HF-HRV reported more positive social functioning. Resting HF-HRV was not related to social functioning. These findings are at apparent odds with the polyvagal theory; however, they complement prior work suggesting that emotional self-regulation could plausibly modulate cardiac vagal control in association with social functioning.

Reduced low-frequency heart rate variability relates to greater intimal-medial thickness of the carotid wall in two samples

INTRODUCTION

We investigated the relationship between heart rate variability and preclinical carotid intima-media thickening, a putative index of atherosclerosis.

METHODS

A sample of 350 men and women (mean age 56.8 years) selected for the presence or absence of untreated hypertension was assessed for heart rate variability at rest and separately for carotid intima-media thickness using duplex ultrasonography (Pittsburgh study). Findings from this sample were cross-validated in a subsample of 68 men drawn from the Kuopio Ischemic Heart Disease Risk Factor trial and selected for the presence or absence of angina.

RESULTS

In both samples, regression analyses, controlling for known risk factors, showed a significant negative relationship between mean carotid intima-media thickness and low-frequency (0.05-0.15 Hz) heart rate variability, but not high-frequency variability.

DISCUSSION

The mechanism underlying this relationship remains unclear. The absence of difference in high-frequency variation questions any interpretation in terms of vagal function; the difference in low-frequency variation may implicate vessel wall characteristics or decreased sympathetic nervous system influence.

CONCLUSION

Decreased amplitude of low-frequency heart rate variability seems associated with a preclinical atherosclerotic index.

Social support and behavior in a stressful situation in relation to myocardial infarction and mortality: who is at risk? Results from prospective cohort study "Men born in 1914," Malmö, Sweden

Coronary heart disease remains an important cause of morbidity and mortality. Much data support the view that social support is associated with coronary heart disease. Participants of the study "Men born in 1914," (414 men) were followed from a baseline measurement in 1982/83 until the end of 1996. At baseline, the men answered a questionnaire on social support and participated in a stressful test where their behavior was categorized as adaptive or maladaptive. This study examined whether social support had a prospective impact on the incidence of myocardial infarction and all-cause mortality when behavior in the stressful task was taken into consideration. The conclusion of the study was that unsatisfactory levels of social support is associated with an increased risk of incident myocardial infarction (HR 2.40, CI 1.36-4.25, p = .003) and premature death (HR 1.99, CI 1.32-3.00, p = .001) but only in men who had shown maladaptive behavior in the test.

Blood pressure response to psychological stressors in adults after prenatal exposure to the Dutch famine

OBJECTIVE

There is increasing evidence that restricted prenatal growth is associated with exaggerated blood pressure responses to stress. We investigated the effect of maternal undernutrition on the adult offspring's stress response.

DESIGN

A historical cohort study.

METHODS

We performed continuous blood pressure and heart rate measurements during a battery of three 5-min physiological stress tests (Stroop test, mirror-drawing test and a public speech task) in 721 men and women, aged 58 years, born as term singletons in Amsterdam at about the time of the Dutch 1944-1945 famine.

RESULTS

During the stress tests, the systolic blood pressure (SBP) rose from baseline by 20 mmHg during the Stroop test, by 30 mmHg during the mirror-drawing test and by 47 mmHg during the public speech task. The SBP and diastolic blood pressure increase during stress was highest among individuals exposed to famine in early gestation compared with unexposed subjects (4 mmHg extra systolic increase, P = 0.04; 1 mmHg diastolic increase, P = 0.1, both adjusted for sex). Exposure during mid and late gestation was not associated with a stress-related increment of blood pressure (P adjusted for sex > 0.6). Correcting for confounders in a multivariable model did not attenuate the association between famine exposure in early gestation and the SBP increment. The heart rate increment was not related to famine exposure during any part of gestation.

CONCLUSION

We found a greater blood pressure increase during stress among individuals exposed to famine in early gestation. Increased stress responsiveness may underlie the known association between coronary heart disease and exposure to famine in early gestation.

Incidence of cardiac events in hypertensive men related to adaptive behavior in stressful encounters

The Serial Color Word Test was administered at baseline to 253 hypertensive men participating in the prospective cohort study of cardiovascular diseases "Men born in 1914" in Malmö, Sweden. This test of psychological adaptation to a stressful encounter was used to investigate whether susceptibility to stress moderates the risk of a cardiac event in association with hypertension. Adaptive behavior, as measured by test performance, can be categorized in two dimensions. The regression dimension refers to linear change of time spent in the test session whereas the variability dimension refers to nonlinear change. Both dimensions consist of four different patterns. At follow-up (mean time = 8.2 +/- 3.5 years), the risk of a cardiac event varied between men with different adaptive patterns. One pattern, the Cumulative-Dissociative pattern of the variability dimension, characterized by a discontinuous and fluctuating time-consumption, was associated to an almost three-fold risk of a cardiac event during follow-up (relative risk [RR], 2.99; 95% confidence interval [CI], 1.33 - 6.70, p = .010) after adjustment for medical-, socioeconomic-, and lifestyle-related factors. No association existed between adaptive patterns and overall mortality.

Age-related differences in ambulatory blood pressure during daily stress: Evidence for greater blood pressure reactivity with age

Prior research on age and emotions has found that older adults may show better physiological regulation to stressful stimuli than do younger adults. However, the stress reactivity literature has shown that age is associated with higher cardiovascular reactivity to laboratory stress (J. R. Jennings et al., 1997). The authors investigated these conflicting findings further by examining daily ambulatory blood pressure in 428 middle-aged to older adults. Consistent with the age and reactivity literature, relatively old individuals showed significantly greater increases in ambulatory diastolic blood pressure compared with younger individuals when dealing with daily stressors. However, results also revealed that relatively old individuals reported less of an increase in negative affect during daily stress compared with their younger counterparts. The results of this study are consistent with the age-related increase in cardiovascular risk but highlight the complex links between stress and different facets of the aging process.

Aging and cardiovascular reactivity to stress: longitudinal evidence for changes in stress reactivity

Although age differences in cardiovascular function are well documented, little research has provided longitudinal evidence for age-related changes in cardiovascular reactivity to stress. In this study, the authors report such data from a follow-up of their prior work (B. N. Uchino, D. Uno, J. Holt-Lunstad, & J. B. Flinders, 1999) with participants between the ages of 30 to 70 (n=108, mean follow-up=10 months, range=7 to 16 months). Results revealed longitudinal evidence for an age-related increase in systolic blood-pressure reactivity and parasympathetic withdrawal to acute stress. The implications of these findings are discussed in light of the increased cardiovascular disease risk with age, as well as the links between aging, emotions, and physiology.

Exaggerated Blood Pressure Responses During Mental Stress Are Prospectively Related to Enhanced Carotid Atherosclerosis in Middle-Aged Finnish Men

Background— Hemodynamic reactions to mental stress may contribute to atherosclerosis. We previously observed cross-sectional relationships between blood pressure reactions to a standardized stress battery and carotid intima-media thickness (IMT) in the Kuopio Ischemic Heart Disease (KIHD) study. These are the first prospective results on this relationship.

Methods and Results— Men from 4 age cohorts (42 to 60 years old at study onset) were challenged with a standardized mental stress battery, and heart rate and blood pressure reactions were assessed. Ultrasound measures of common carotid IMT were collected at this time and 7 years later as noninvasive markers of atherosclerosis. Data were collected from a sample of 756 men at both times. Systolic blood pressure reactions to mental stress at study onset were positively related to mean carotid IMT 7 years later (β=0.035, P =0.001, by blood pressure quartile, IMT=0.91, 0.93, 0.96, 1.00 mm) and to the progression of IMT (β=0.020, P =0.006, by blood pressure quartile, ΔIMT=0.08, 0.09, 0.11, 0.11 mm). Similar significant relations were shown for maximal IMT and plaque height. Diastolic blood pressure responses were less strongly related to carotid IMT than were systolic responses. Heart-rate responses were unrelated. Adjustment for standard risk factors did not substantially reduce the relation between systolic blood pressure reactivity and the progression of mean carotid IMT (standardized β=0.059, P =0.026), maximal carotid IMT (standardized β=0.084, P =0.006), or plaque height (standardized β=0.093, P =0.008).

Conclusions— The degree of systolic blood pressure reactivity to mental challenge is prospectively related to carotid IMT in middle-aged and older men, independent of known risk factors.

Prognostic significance of ventricular arrhythmia modified by ability to adapt to stressful situations

BACKGROUND

Ventricular arrhythmia is a risk factor for myocardial infarction and mortality but many individuals with this abnormality live long and healthy lives. The aim of this study is to analyse the prognostic significance of frequent and complex ventricular arrhythmia in men who differed regarding ability to adapt to a stressful situation.

DESIGN

Prospective cohort study.

METHODS

The serial Color Word Test is a semi-experimental way to assess how individuals behave in a stressful encounter. This test was included in the prospective cohort study 'Men born in 1914' together with 24-h ambulatory electrocardiographic recordings at a baseline examination in 1982/83. Behaviour in the test was categorized as either adaptive or maladaptive. Behaviour in the test and occurrence of ventricular arrhythmia at baseline were analyzed in relation to incidence of myocardial infarction and mortality during approximately 14 years of follow-up.

RESULTS

Multivariate analyses showed that ventricular arrhythmia was not associated with the incidence of myocardial infarction or all-cause mortality in the presence of an adaptive behaviour. Ventricular arrhythmia together with a maladaptive behaviour was associated with the incidence of myocardial infarction [relative risk (RR) 2.43; 95% confidence interval (CI) 1.37 to 4.31] and with all-cause mortality (RR 1.56; 95% CI 1.01 to 2.41) during follow-up.

CONCLUSIONS

A maladaptive behaviour in a stressful encounter makes men with electrocardiographically detected ventricular arrhythmias more vulnerable and thereby exposed to an increased risk of a future myocardial infarction and overall mortality.

Promoting communication with older adults: protocols for resolving interpersonal conflicts and for enhancing interactions with doctors

In this paper, we review the importance of effective communication in older adulthood, and ideas for promoting it. We focus on theoretical and applied work in two communicative encounters that have particular relevance for older adult health, i.e., interpersonal conflict and visits with a healthcare provider. Little applied work has aimed to adapt training protocols for older adults in these two areas. We will present training protocols we have developed in constructive conflict resolution for older adults, and on enhancing doctor-patient communication. We present these protocols to stimulate ideas on the part of the reader on how to further develop and refine training efforts for older adults in effective communication.

Adaptive behavior in stressful situations in relation to postinfarction mortality results from prospective cohort study "Men Born in 1914" in Malmo, Sweden

The serial Color Word Test, which is a semi-experimental way to differentiate adaptive behavior in stressful situations, was administered at baseline to men participating in the prospective cohort study "Men born in 1914". During follow-up, from 1982-1983 until December 31, 1996, 133 men experienced a myocardial infarction. Four patterns of adaptive behavior in 2 separate dimensions, the Variability and the Regression, can be discerned during testing. These patterns were compared regarding outcome following the myocardial infarction. The Cumulative-dissociative pattern of the Regression dimension was univariately associated with mortality within 28 days (OR 5.75, CI 1.85-17.88, p = .003). Dissociative (OR 3.87, CI 1.21-12.42, p = .023) and Cumulative-dissociative (OR 5.46, CI 1.66-17.96, p = .005) patterns, of the same dimension, were independently associated with mortality within one year. Specific difficulties in adaptation to stressful situations were associated with increased risk of death following a myocardial infarction. In this male sample, these difficulties could be identified with the serial Color Word Test.

Socioeconomic status and hemodynamic recovery from mental stress

We assessed the changes in cardiac index and total peripheral resistance underlying blood pressure reactions and recovery from acute mental stress, in relation to socioeconomic status. A sample of 200 men and women aged 47-59 years was divided on the basis of occupation into higher, intermediate, and lower socioeconomic status groups. Blood pressure was monitored using the Portapres, and hemodynamic measures were derived by Modelflow processing of the arterial pressure waveform. Blood pressure increases during two stressful behavioral tasks were sustained by increases in cardiac index and total peripheral resistance. During the 45-min posttask recovery period, cardiac index fell below baseline levels, whereas peripheral resistance remained elevated. Peripheral resistance changes during recovery varied with socioeconomic status and blood pressure stress reactivity, with particularly high levels in reactive low status participants. Results are consistent with the hypothesis that disturbances of stress-related autonomic processes are relevant to the social gradient in cardiovascular disease risk.

Cardiovascular reactivity and initiate/avoid patterns of marital communication: a test of Gottman's psychophysiologic model of marital interaction

Gottman's (1990, 1991; Gottman and Levenson, 1988) psychophysiologic model of marital interaction was tested in 60 married couples. Participants were classified as avoiders or initiators of relationship problem discussions by trained coders observing videotaped semistructured interviews. Blood pressure (BP) and heart rate reactivity was assessed during the cold pressor test, during a mental math test, while watching a marital argument on video, and during a conjoint interview. As hypothesized, avoiders had significantly greater systolic BP reactivity during the interview. Additionally, husbands who interacted with avoider wives had significantly greater diastolic and systolic BP reactivity than did husbands of initiator wives. Initiator husbands, in particular, who were married to avoider wives had greater systolic BP reactivity. These results both support Gottman's psychophysiologic model and suggest modifications of it.

Adaptive behavior in stressful situations and stroke incidence in hypertensive men: results from prospective cohort study "men born in 1914" in Malmö, Sweden

BACKGROUND AND PURPOSE

Although hypertension is a major risk factor for stroke, many hypertensive persons remain healthy. The aim of the present study was to analyze whether adaptation in a stressful situation was associated with the incidence of stroke in hypertensive men.

METHODS

Two hundred thirty-eight hypertensive men were followed from baseline in 1982/1983 until first stroke, death, or December 31, 1996. Adaptation to stress was studied with the serial Color-Word Test. In the Regression dimension, 4 patterns of adaptation could be distinguished according to mastering of the test. Successful mastering of the test was shown in stabilized patterns, increasing difficulty in cumulative patterns, fluctuating difficulty in dissociative patterns, and fluctuating difficulty that increased during testing in cumulative-dissociative patterns. The patterns were compared regarding stroke incidence.

RESULTS

Forty-three men experienced a stroke during follow-up. Stroke rates per 1000 person-years were 12.6 for men with stabilized patterns, 14.3 for men with cumulative patterns, 16.2 for men with dissociative patterns, and 31.2 for men with cumulative-dissociative patterns. Multivariate analysis, adjusted for relevant cerebrovascular risk factors, showed that the cumulative-dissociative pattern of the Regression dimension was associated with an increased risk of stroke during follow-up (relative risk 3.00, 95% CI 1.32 to 6.81).

CONCLUSIONS

The specific behavior pattern, characterized by the greatest difficulties in managing the test, was associated with incidence of stroke in hypertensive men. One interpretation is that hypertensive men who chronically fail to find successful strategies in stressful situations are vulnerable to the damaging effects of stress and thereby at an increased risk of a future stroke.

Heterogeneity in the social networks of young and older adults: prediction of mental health and cardiovascular reactivity during acute stress

We examined the utility of a broad framework that separated positive, negative, and ambivalent social network members. One hundred thirty-three young and older participants completed the social relationships index, measures of mental health, and a cardiovascular reactivity protocol. Results replicated prior research on the beneficial influence of positive (supportive) ties on psychological outcomes. More important, analyses also revealed that the number of ambivalent network ties predicted age-related differences in depression and sympathetic control of heart rate reactivity during stress. The statistical interactions between age and ambivalent ties on cardiovascular responses during stress were not changed when statistically controlling for other social network categories, demographic variables, and various personality factors. These data suggest that social network ambivalence was a relatively unique predictor of cardiovascular reactivity and highlight the utility of separating the variance due to positive, negative, and ambivalent network ties. Implications for the study of social relationships, physiological processes, and health outcomes are also discussed.

Anticipatory blood pressure responses to exercise are associated with left ventricular mass in Finnish men: Kuopio Ischemic Heart Disease Risk Factor Study

BACKGROUND

Exaggerated cardiovascular reactivity to psychological demands may contribute to the development of left ventricular (LV) hypertrophy. We examined the cross-sectional association between anticipatory blood pressure (BP) responses to bicycle exercise and LV mass in the Kuopio Ischemic Heart Disease Risk Factor Study, a population-based epidemiological sample.

METHODS AND RESULTS

Among 876 men from 4 age cohorts (ages 42, 48, 58, and 64 years), we collected echocardiographic assessments of LV mass along with measures of BP response taken before bicycle ergometry testing. Anticipatory BP responses were positively associated with LV mass, with significant associations only among younger (age <50 years) subjects with elevated resting pressures (3-way interactions for anticipatory BP x age x resting pressure for systolic and diastolic BP, all P:<0.05; for younger subjects with elevated systolic BP, P:<0. 01; and for younger subjects with elevated diastolic BP, P:<0.001). Among these subgroups, exaggerated anticipatory BP responses (top quartile) were associated with an incremental increase in LV mass of 10% or greater, corrected for body surface area. Results remained significant after adjusting for age, education, salt consumption, and resting BP, and the pattern of findings was maintained among men with no previous history of cardiovascular disease.

CONCLUSIONS

The tendency to show exaggerated pressor responses to psychological demands may be a significant independent correlate of LV mass, especially among young men with high resting pressures. This is the first study to examine such associations in a middle-aged population sample.

Influence of cholesterol and fasting insulin levels on blood pressure reactivity

OBJECTIVE

This study examined how cholesterol and fasting insulin levels are related to blood pressure reactivity to behavioral stressors.

METHODS

Subjects (N = 116) were 20 to 52 years old, at 80% to 150% of ideal weight, and had an average fasting cholesterol level of 183 mg/dl. Stressor tasks included mirror star tracing and a videotaped speech task. Changes from baseline were calculated for systolic and diastolic blood pressure.

RESULTS

Neither cholesterol nor insulin was independently related to blood pressure change scores. However, after controlling for body mass, a two-way analysis of variance revealed a significant cholesterol-by-insulin interaction for change in diastolic blood pressure (p = .022). Subjects in the high-cholesterol/high-insulin group showed the greatest increase in diastolic blood pressure reactivity.

CONCLUSIONS

In a general population, people with a below-average cholesterol level experience only moderate cardiovascular reactivity to mental stressors regardless of their fasting insulin level. However, for people with an above-average cholesterol level, fasting insulin level is an important factor in determining potential reactivity to mental stressors. These findings highlight the importance of adequate sample size to allow for the analysis of such interactions in future studies of cholesterol, insulin, and blood pressure reactivity.

Health psychology: mapping biobehavioral contributions to health and illness

Our evolving understanding of how psychosocial and behavioral factors affect health and disease processes has been marked by investigation of specific relationships and mechanisms underlying them. Stress and other emotional responses are components of complex interactions of genetic, physiological, behavioral, and environmental factors that affect the body's ability to remain or become healthy or to resist or overcome disease. Regulated by nervous, endocrine, and immune systems, and exerting powerful influence on other bodily systems and key health-relevant behaviors, stress and emotion appear to have important implications for the initiation or progression of cancer, HIV, cardiovascular disease, and other illnesses. Health-enhancing and health-impairing behaviors, including diet, exercise, tobacco use, and protection from the sun, can compromise or benefit health and are directed by a number of influences as well. Finally, health behaviors related to being ill or trying to avoid disease or its severest consequences are important. Seeking care and adhering to medical regimens and recommendations for disease surveillance allow for earlier identification of health threats and more effective treatment. Evidence that biobehavioral factors are linked to health in integrated, complex ways continues to mount, and knowledge of these influences has implications for medical outcomes and health care practice.

Exaggerated blood pressure responses during mental stress are associated with enhanced carotid atherosclerosis in middle-aged Finnish men: findings from the Kuopio Ischemic Heart Disease Study

BACKGROUND

Exaggerated cardiovascular reactivity to mental stress is hypothesized to increase atherosclerotic risk. We examined this hypothesis using cross-sectional data from the Kuopio Ischemic Heart Disease study, a population-based epidemiological sample.

METHODS AND RESULTS

901 Eastern Finnish men from four age cohorts (age, 42 to 60 years) were administered a standardized testing battery to assess cardiovascular reactivity to mental stress. Ultrasound measures of intima-medial thickness (IMT) and plaque height from the common carotid arteries were used as noninvasive markers of atherosclerosis. Diastolic blood pressure (DBP) responses to mental stress were significantly associated with mean IMT (b=.021, P=.006), maximum IMT (b=.026, P=.013), and mean plaque height (b=.017, P=.041). Significant associations were also shown between stress-related systolic blood pressure (SBP) reactivity and mean IMT (b=.0151, P=.042). When examined separately by age, associations with IMT were significant only in the youngest half of the sample (age, 46 and 52 years, n=433; for mean IMT, DBP b=.033, P=.0002, SBP b=.0266, P=.003; for maximum IMT, DBP b=.039, P=.002, SBP b=.032, P=.011). Results remained significant in the younger subjects after adjustment for smoking, lipid profiles, fasting glucose, and resting blood pressure (b=.024, P=.011); results also remained significant in a subgroup of unmedicated younger subjects without symptomatic cardiovascular disease (n=135; for SBP reactivity, b=.031, P=.036; for DBP, b=.037, P=.007).

CONCLUSIONS

The tendency to show exaggerated pressor responses to mental stress is a significant independent correlate of atherosclerosis in this population sample of Finnish men. The effect does not appear to be accounted for by the confounding influence of other risk factors or preexisting clinical disease.