Blood pressure reactivity predicts myocardial infarction among treated hypertensive patients

Age-related alterations in the cardiovascular responses to acute exercise in males and females: role of the exercise pressor reflex

Autonomic adjustments of the cardiovascular system are critical for initiating and sustaining exercise by facilitating the redistribution of blood flow and oxygen delivery to meet the metabolic demands of the active skeletal muscle. Afferent feedback from active skeletal muscles evokes reflex increases in sympathetic nerve activity and blood pressure (BP) (i.e., exercise pressor reflex) and contributes importantly to these primary neurovascular adjustments to exercise. When altered, this reflex contributes significantly to the exaggerated sympathetic and BP response to exercise observed in many cardiovascular-related diseases, highlighting the importance of examining the reflex and its underlying mechanism(s). A leading risk factor for the pathogenesis of cardiovascular disease in both males and females is aging. Although regular exercise is an effective strategy for mitigating the health burden of aging, older adults face a greater risk of experiencing an exaggerated cardiovascular response to exercise. However, the role of aging in mediating the exercise pressor reflex remains highly controversial, as conflicting findings have been reported. This review aims to provide a brief overview of the current understanding of the influence of aging on cardiovascular responses to exercise, focusing on the role of the exercise pressor reflex and proposing future directions for research. We reason that this review will serve as a resource for health professionals and researchers to stimulate a renewed interest in this critical area.

OLD IDEAS, NEW DIRECTIONS: RE-EXAMINING THE PREDICTIVE UTILITY OF THE HEMODYNAMIC PROFILE OF THE STRESS RESPONSE IN HEALTHY POPULATIONS

The 'reactivity hypothesis' has a long and fruitful history in health psychology and behavioural medicine, with elements of its thesis taken as core and others lost in the plethora of research on its utility as a theory of psychosomatic disease. One such thesis is that the underlying hemodynamic profile of the stress response may be particularly revealing when detailing the impact of psychological stress on the development of cardiovascular disease. This paper re-examines old ideas surrounding the hemodynamic profile of the stress response, asking why its health-predictive properties were never fully explored. Further, this paper reviews the evidence that a vascular profile of stress responding may be especially predictive of disease development, particularly in the case of hypertension. In addition, measurement of hemodynamic profile as well as its known psychosocial moderators are reviewed including how examination of patterns of cardiovascular-stress response adaptation may extend the field. This paper highlights that the extension of the reactivity hypothesis to include both hemodynamic profile and patterns of cardiovascular stress-response adaptation may hold much explanatory power in detailing the impact of how stress responding and stress tolerance promotes disease development.

Alpha-Adrenergic Mechanisms in the Cardiovascular Hyperreactivity to Norepinephrine-Infusion in Essential Hypertension

AIMS

Essential hypertension (EHT) is characterized by cardiovascular hyperreactivity to stress but underlying mechanism are not fully understood. Here, we investigated the role of α-adrenergic receptors (α-AR) in the cardiovascular reactivity to a norepinephrine (NE)-stress reactivity-mimicking NE-infusion in essential hypertensive individuals (HT) as compared to normotensive individuals (NT).

METHODS

24 male HT and 24 male NT participated in three experimental trials on three separate days with a 1-min infusion followed by a 15-min infusion. Trials varied in infusion-substances: placebo saline (Sal)-infusions (trial-1:Sal+Sal), NE-infusion without (trial-2:Sal+NE) or with non-selective α-AR blockade by phentolamine (PHE) (trial-3:PHE+NE). NE-infusion dosage (5µg/ml/min) and duration were chosen to mimic duration and physiological effects of NE-release in reaction to established stress induction protocols. We repeatedly measured systolic (SBP) and diastolic blood pressure (DBP) as well as heart rate before, during, and after infusions.

RESULTS

SBP and DBP reactivity to the three infusion-trials differed between HT and NT (p's≤.014). HT exhibited greater BP reactivity to NE-infusion alone compared to NT (trial-2-vs-trial-1: p's≤.033). Group differences in DBP reactivity to NE disappeared with prior PHE blockade (trial-3: p=.26), while SBP reactivity differences remained (trial-3: p=.016). Heart rate reactivity to infusion-trials did not differ between HT and NT (p=.73).

CONCLUSION

Our findings suggest a mediating role of α-AR in DBP hyperreactivity to NE-infusion in EHT. However, in SBP hyperreactivity to NE-infusion in EHT, the functioning of α-AR seems impaired suggesting that the SBP hyperreactivity in hypertension is not mediated by α-AR.

Cardiovascular reactivity to acute stress: Attachment styles and invisible stranger support

While the benefits of social support for physiological health are well established, the underlying pathways by which support can influence cardiovascular reactivity (CVR) are still being elucidated. In the present study, we adapted an attachment framework to further explore the support-CVR link. Specifically, we experimentally tested the effect of attachment and social support on CVR by manipulating the provision of invisible support from a stranger, across individuals with secure, anxious and avoidant attachment styles. Employing a 3 × 2 design, a sample of young adults (N = 138) from across each of the three attachment styles were randomly assigned to either an invisible support (from a stranger), or no support, condition. All participants were subject to an acute standardised stress testing protocol where cardiovascular indices were monitored throughout. Results from a factorial ANOVA showed no significant interaction between support and attachment on any cardiovascular reactivity parameter (SBP, DBP, HR) or any main effect of attachment or support. These findings suggest that, in this case, social support was not effective in buffering the effects of stress across various attachment styles. The benefits of incorporating a developmental perspective to the study of social support and health are discussed.

The Effect of Perimenopausal Transdermal Estradiol and Micronized Progesterone on Markers of Risk for Arterial Disease

BACKGROUND

The arterial effects of hormone therapy remain controversial. This study tested the effects of transdermal estradiol plus intermittent micronized progesterone (TE + IMP) in healthy perimenopausal and early postmenopausal women on several mechanisms involved in the pathophysiology of arterial disease.

METHODS

Healthy perimenopausal and early postmenopausal women, ages 45 to 60 years, were enrolled in this randomized, double-blind, placebo-controlled trial. Women were randomized to receive TE (0.1 mg/day) + IMP (200 mg/day for 12 days) or identical placebo patches and pills for 12 months. Outcomes included: change in stress reactivity composite z-score (combining inflammatory, cortisol, and hemodynamic responses to a standardized psychological laboratory stressor); flow-mediated dilation (FMD) of the brachial artery (an index of vascular endothelial function); baroreflex sensitivity; and metabolic risk (presence of the metabolic syndrome or insulin resistance), all assessed at baseline and at months 6 and 12.

RESULTS

Of 172 women enrolled, those assigned to TE + IMP tended to have higher resting baroreflex sensitivity than those assigned to placebo across the 6- and 12-month visits. Although treatment groups did not differ in terms of the other prespecified outcomes, a significant treatment-by-age interaction was found for FMD and stress reactivity such that an age-related decrease in FMD and increase in stress reactivity were seen among women assigned to placebo but not those assigned to TE + IMP. Women on TE + IMP also had lower resting diastolic blood pressure, lower levels of low-density lipoprotein cholesterol, and higher baroreflex sensitivity during stress testing.

CONCLUSIONS

TE + IMP tended to improve cardiac autonomic control and prevented age-related changes in stress reactivity and endothelial function among healthy perimenopausal and early postmenopausal women.

Impaired neuronal nitric oxide synthase-mediated vasodilator responses to mental stress in essential hypertension

Neuronal NO synthase (nNOS) regulates blood flow in resistance vasculature at rest and during mental stress. To investigate whether nNOS signaling is dysfunctional in essential hypertension, forearm blood flow responses to mental stress were examined in 88 subjects: 48 with essential hypertension (42±14 years; blood pressure, 141±17/85±15 mm Hg; mean±SD) and 40 normotensive controls (38±14 years; 117±13/74±9 mm Hg). A subsample of 34 subjects (17 hypertensive) participated in a single blind 2-phase crossover study, in which placebo or sildenafil 50 mg PO was administered before an intrabrachial artery infusion of the selective nNOS inhibitor S-methyl-l-thiocitrulline (SMTC, 0.05, 0.1, and 0.2 μmol/min) at rest and during mental stress. In a further subsample (n=21) with an impaired blood flow response to mental stress, responses were measured in the presence and absence of the α-adrenergic antagonist phentolamine. The blood flow response to mental stress was impaired in hypertensive compared with normotensive subjects (37±7% versus 70±8% increase over baseline; P<0.001). SMTC blunted responses to mental stress in normotensive but not in hypertensive subjects (reduction of 40±11% versus 3.0±14%, respectively, P=0.01, between groups). Sildenafil reduced the blood flow response to stress in normotensive subjects from 89±14% to 43±14% (P<0.03) but had no significant effect in hypertensive subjects. Phentolamine augmented impaired blood flow responses to mental stress from 39±8% to 67±13% (P<0.02). Essential hypertension is associated with impaired mental stress-induced nNOS-mediated vasodilator responses; this may relate to increased sympathetic outflow in hypertension. nNOS dysfunction may impair vascular homeostasis in essential hypertension and contribute to stress-induced cardiovascular events.

Physiological correlates of beat-to-beat, ambulatory, and day-to-day home blood pressure variability after transient ischemic attack or minor stroke

BACKGROUND AND PURPOSE

Visit-to-visit and day-to-day variability in systolic blood pressure (SBP) are associated with an increased risk of stroke, more strongly than variability on 24-hour ambulatory BP monitoring, but underlying physiological mechanisms are unclear. We related potentially relevant physiological characteristics to beat-to-beat, ambulatory, and day-to-day BP variability to identify underlying mechanisms and potential therapeutic targets.

METHODS

BP variability (coefficient of variation [CV]) on 1-month home BP monitoring (3 sitting readings, 3× daily), on 24-hour ambulatory BP monitoring, and on 5-minute beat-to-beat monitoring was related to BP reactivity (to mental arithmetic), arterial aging (aortic stiffness: carotid-femoral pulse wave velocity; aortic pulsatility), heart rate variability (CV of normal-to-normal R-R interval), and orthostatic responses.

RESULTS

In 223 patients within 6 weeks of a transient ischemic attack or minor stroke, beat-to-beat and home SBP-CVs were associated with response to arithmetic (beat-to-beat odds ratio per SD=1.64; P<0.0001 and home BP monitoring, 1.41; P=0.025), aortic stiffness (1.84; P<0.0001 and 1.31; P=0.04), aortic pulsatility (1.98; P<0.0001 and 1.61; P<0.0001), and heart rate variability-CV of normal-to-normal R-R interval (1.34; P=0.03 and 1.35; P=0.03), independently of age, sex, and aortic BP. Orthostatic BP changes were associated only with SBP-CV on home BP monitoring (0.62; P=0.002). In contrast, no physiological measures were associated with within-day BP variability on awake ambulatory BP monitoring except response to mental arithmetic (1.40; P=0.01).

CONCLUSIONS

Beat-to-beat and day-to-day SBP variability, but not variability on ambulatory BP monitoring, had similar physiological correlates, suggesting common underlying mechanisms and identifying potentially treatable targets that may be responsible for the relationship between SBP variability and stroke risk.

Blood Pressure Reactivity to an Anger Provocation Interview Does Not Predict Incident Cardiovascular Disease Events: The Canadian Nova Scotia Health Survey (NSHS95) Prospective Population Study

We examined the association between blood pressure (BP) reactivity to an anger provocation interview and 10-year incident CVD events in 1,470 adults from the population-based 1995 Nova Scotia Health Survey (NSHS95). In an unadjusted model, those in the highest decile of systolic BP reactivity were more than twice as likely to have an incident CVD event compared to those in the decile with no reactivity (HR = 2.33, 95% CI = 1.15 - 4.69, P = 0.02). However, after adjusting for age and sex, and then also for Framingham risk score, body mass index, and education, this relationship was attenuated and not statistically significant. Diastolic BP reactivity was not associated with CVD incidence in any model. Individual differences in BP reactivity to a laboratory-induced, structured anger provocation interview may not play a major role in clinical CVD endpoints.

Social encounters in daily life and 2-year changes in metabolic risk factors in young women

Research shows that poor social ties increase risks of morbidity and mortality from cardiovascular disease (CVD). However, little is known about the nature of everyday social encounters that give rise to this association, or when in the course of development they begin to shape disease-relevant biological processes. In this study, 122 adolescent females recorded the qualities of their everyday social interactions using electronic diaries. At the same time we measured components of the metabolic syndrome, a precursor to CVD that includes central adiposity, high blood pressure, insulin resistance, and lipid dysregulation. Metabolic symptoms were reassessed 12 and 24 months later. Hierarchical linear modeling revealed an association between negative social interactions and metabolic symptom trajectories. To the extent that participants had more intense negative social encounters in daily life, they showed increasing scores on a composite indicator of metabolic risk over 2 years. This association was independent of a variety of potential confounders, and persisted when symptoms of depression and broader personality traits were controlled. There was no association between positive social encounters and metabolic risk trajectories. These findings suggest that even in otherwise healthy adolescents, abrasive social encounters may accelerate the progression of early stages of CVD.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects and, conversely, that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife--a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated, that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common, mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of estrogen (E2). This review summarizes data supporting these contentions with the intent of placing depression and estrogen therapy in their proper physiologic context.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects, and conversely that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife-a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen (E2) deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common and mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of E2. This review summarizes data supporting this contention with the intent of placing depression and E2 therapy in their proper physiologic context.

Increases in B-type natriuretic peptide after acute mental stress in heart failure patients are associated with alcohol consumption

OBJECTIVE

The aim of this study was to investigate in heart failure (HF) patients whether acute mental stress induces increases in the HF-severity biomarker B-type natriuretic peptide (BNP) and if alcohol consumption is associated with such stress-induced increases.

METHOD

Twenty-one male HF patients and 19 male non-HF controls (M = 56 years, SEM = 2) underwent a 15-minute acute mental stress test combining public speaking and mental arithmetic. Plasma levels of BNP were determined immediately before as well as 2 hours after the stress test. Alcohol consumption was assessed by self-reported number of drinks per month and history of use.

RESULTS

HF patients had higher BNP levels before and after stress, F(1, 38) = 23.42, p < .001, and showed greater stress-induced increases in BNP levels, F(1, 38) = 4.52, p = .04, compared with controls. HF status (beta = .32, p = .015, deltaR(2) = .10) and higher alcohol consumption ((beta = .61, p< .001, deltaR(2) = .37) were independently associated with higher BNP stress increases. Moreover, higher alcohol consumption moderated the greater BNP stress increases in HF patients but not in controls (p = .49, p < .001, delta(2) = .20), although alcohol consumption did not differ between groups.

CONCLUSIONS

For individuals with HF, particularly those who drink moderate to more substantial amounts of alcohol, exposure to acute psychological stress leads to increases in circulating levels of BNP, a biomarker which is associated with increased morbidity and mortality in HF.

Avoidance may be bad for the heart: a comparison of dyadic initiator tendency in cardiac rehabilitation patients and matched controls

The psychophysiologic model of marital distress proposes that demand/withdraw dyadic communication activates cardiovascular reactivity in the withdrawing partner, which eventually leads to cardiac illness. Thirty-one patients (23 men and 8 women) in a cardiac rehabilitation program were matched to community controls. Participants completed the Initiator Style Questionnaire, a measure of a person's tendency to initiate relationship problem discussions. As hypothesized, cardiac rehabilitation patients (M = 42.53, 95% CI 37.6-47.5) reported being less likely to initiate relationship problem discussions than did community controls (M = 60.79, 95% CI 54.7-66.8). Consistent with the model, cardiac patients rated themselves as less initiating (M = 39.12, 95% CI 32.96-45.28) than they rated their partners (M = 45.94, 95% CI 38.98-52.90); in contrast, matched controls rated themselves as more initiating (M = 63.04, 95% CI 57.36-68.70) than they rated their partners (M = 58.54, 95% CI 42.98-67.78). Further analysis found that female patients accounted for this finding. The results add further support for the psychophysiologic model.

A review of neuroimaging studies of stressor-evoked blood pressure reactivity: emerging evidence for a brain-body pathway to coronary heart disease risk

An individual's tendency to show exaggerated or otherwise dysregulated cardiovascular reactions to acute stressors has long been associated with increased risk for clinical and preclinical endpoints of coronary heart disease (CHD). However, the 'brain-body' pathways that link stressor-evoked cardiovascular reactions to CHD risk remain uncertain. This review summarizes emerging neuroimaging research indicating that individual differences in stressor-evoked blood pressure reactivity (a particular form of cardiovascular reactivity) are associated with activation patterns in corticolimbic brain areas that are jointly involved in processing stressors and regulating the cardiovascular system. As supported empirically by activation likelihood estimates derived from a meta-analysis, these corticolimbic areas include divisions of the cingulate cortex, insula, and amygdala--as well as networked cortical and subcortical areas involved in mobilizing hemodynamic and metabolic support for stress-related behavioral responding. Contextually, the research reviewed here illustrates how behavioral medicine and health neuroscience methods can be integrated to help characterize the 'brain-body' pathways that mechanistically link stressful experiences with CHD risk.

High cholesterol and coronary heart disease in younger men: the potential role of stress induced exaggerated blood pressure response

It is well known that by far the strongest association between serum cholesterol levels and the risk of coronary heart disease or related adverse events is found in younger men. The question is - what is different about this age-gender subgroup? It has been suggested that this enhanced risk is seen in younger men because of unique exposure to stress. While stress is known to raise cholesterol levels, the magnitude of the elevation appears insufficient to account for the observed association between cholesterol levels and CHD in young men. An hypothesis is presented which suggests that part and perhaps all of this association is due to the relationship between cholesterol levels and exaggerated blood pressure response to stress, i.e. individuals who exhibit this hyper-response also tend to have significantly elevated cholesterol levels. Given that both stress and an exaggerated blood pressure response to stress are also risk factors for CHD, this could influence the relationship between CHD risk and cholesterol in this age group even if multivariate analysis includes casual blood pressure. This is important since in risk assessment, especially among young men, cholesterol levels play an important role.

Renal dysfunction and ischemic heart disease mortality in a hypertensive population

OBJECTIVE

While recent studies indicate that renal dysfunction may be predictive of all-cause mortality and cardiovascular disease (CVD) outcomes in hypertensive individuals, there has been little attention to the specific association of ischemic heart disease (IHD) mortality and renal function. This study examines the relationship between IHD mortality and baseline glomerular filtration rate (GFR) (estimated by the Cockcroft and Gault formula) among treated hypertensive subjects.

DESIGN

A prospective cohort study of participants in a worksite-based antihypertensive treatment program in New York City (1981-1999).

PATIENTS

We studied 9929 subjects who had at least 6 months follow-up (mean 9.6 years) with a baseline serum creatinine.

MAIN OUTCOME MEASURES

IHD death outcomes (n=343) ascertained from the National Death Index.

RESULTS

Multivariate Cox proportional hazard models were constructed adjusting for known cardiovascular risk factors. Mean GFR of the cohort was 91.6 ml/min per 1.73 m. Those with lower GFR were more likely to be older, female, White, report a history of cardiovascular disease, have higher cholesterol and blood urea nitrogen values, and lower hemoglobin and body mass index than those with highest GFR. After adjustment for known cardiovascular risk factors, the risk of IHD death increased progressively as the GFR decreased. Hazard ratio for IHD mortality for each 10-unit reduction of estimated GFR below the normal threshold of >or=90 ml/min per 1.73 m was 1.33 (95% confidence interval 1.17, 1.50; P<0.001).

CONCLUSIONS

The results of this study suggest an independent inverse association between estimated GFR and IHD mortality among treated hypertensive individuals.

Transiently elevated diastolic blood pressure is associated with a gender-dependent effect on cardiovascular risk

We assessed the morbidity and mortality of subjects with transiently elevated diastolic pressure in the General Practice Hypertension Study Group (GPHSG) population. A total of 23 578 patients (aged 18-65 years) from seven UK general practices were screened in 1974 for a diastolic blood pressure (DBP4) of > or = 90 mmHg. Two further readings of DBP4 determined hypertensive (either DBP4 > or = 90 mmHg) or transient hypertensive (both DBP4 < 90 mmHg) status. Transients (n = 850) were matched with normotensive controls (n = 824) and risk ratios calculated over a mean follow-up of 18.7 years. Rescreening was conducted in six of the practices (n = 20 942) after 7.7 years. Male transients had a higher relative hazard for cardiovascular mortality than controls (11.8%, 8.6%, adjusted relative hazard 1.59, P = 0.056). Female transients had a lower relative hazard for cardiovascular mortality than controls (3.6%, 5.4%, adjusted relative hazard 0.39, P = 0.018). In all, 422 patients with transient hypertension were rescreened along with 367 matched controls. Significantly more transients were on antihypertensive treatment compared with their controls (odds ratio (OR) [95% CI]) for both male (4.2 [1.6-11.1]) and female patients (2.4 [1.0-5.56]) and more untreated female transients developed hypertension. Male transients had a higher rates of diabetes mellitus (adj OR = 5.1, P = 0.04) and stroke (adj OR 15.9, P = 0.03). This study has shown that transiently elevated DBP in GPHSG is associated with a significantly higher risk of later hypertension in men and women and of diabetes, stroke and cardiovascular mortality in men. Women with this condition have a significantly lower cardiovascular mortality.

Is there a functional neural correlate of individual differences in cardiovascular reactivity?

OBJECTIVE

The present study tested whether individuals who differ in the magnitude of their blood pressure reactions to a behavioral stressor also differ in their stressor-induced patterns of functional neural activation.

METHODS

Sixteen participants (7 men, 9 women aged 47 to 72 years) were classified as high (n = 8) or low (n = 8) blood pressure reactors by the magnitude and temporal consistency of their systolic blood pressure (SBP) reaction to a Stroop color-word interference stressor. Both high and low SBP reactors completed this Stroop stressor while their task-related changes in blood pressure and functional neural activity were assessed in a blocked functional magnetic resonance imaging design.

RESULTS

In both high and low SBP reactors, the Stroop-stressor engaged the anterior cingulate, orbitofrontal, insular, posterior parietal, and the dorsolateral prefrontal regions of the cortex, the thalamus, and the cerebellum. Compared with low reactors, however, high reactors not only showed a larger magnitude increase in SBP to the Stroop stressor, but also an increased activation of the posterior cingulate cortex.

CONCLUSION

A behavioral stressor that is used widely in cardiovascular reactivity research, the Stroop stressor, engages brain systems that are thought to support both stressor processing and cardiovascular reactivity. Increased activation of the posterior cingulate, a brain region implicated in vigilance to the environment and evaluative emotional processes, may be a functional neural correlate of an individual's tendency to show large-magnitude (exaggerated) blood pressure reactions to behavioral stressors.

Transdermal Versus Oral Estrogen Therapy in Postmenopausal Smokers: Hemodynamic and Endothelial Effects

OBJECTIVE

To test the hypothesis that, in postmenopausal smokers, transdermal estrogen would be more effective than oral estrogen in reducing blood pressure (BP) and vascular and norepinephrine responses to stress and in increasing endothelial function and vascular beta2-adrenoceptor responsivity.

METHODS

By using a randomized, double-blind, placebo-controlled design, 82 healthy postmenopausal smokers were tested before and after 6 months of therapy with transdermal estrogen (0.05 mg/d) plus a progestin (2.5 mg/d; n = 31), oral conjugated equine estrogen (0.625 mg/d) plus a progestin (2.5 mg/d; n = 30), or placebo (n = 21). Dependent measures included resting and stress-induced increases in BP, total peripheral resistance, and plasma norepinephrine, as well as endothelial function and beta-adrenoceptor responsivity.

RESULTS

When compared with placebo, the transdermal estrogen group showed more consistent reductions in total peripheral resistance at rest and in response to mental stress than the oral estrogen group. Only the transdermal group showed treatment-related reductions in behavioral stress norepinephrine, baseline rest, and behavioral stress BP levels, and increases in vascular beta2-adrenoceptor responsivity and endothelium-dependent vasodilation. Posttreatment concentrations of serum estradiol and estrone were lower and the serum estradiol/estrone ratio closer to pre-menopausal values in the group receiving transdermal estrogen compared with oral estrogen.

CONCLUSION

Six months of transdermal estrogen therapy is associated with greater reductions in measures reflecting vascular sympathetic tone than oral estrogen therapy in healthy postmenopausal smokers. Thus, transdermal estrogen may be associated with a more favorable risk/ benefit ratio in postmenopausal smokers, a group at high risk of osteoporosis and cardiovascular disease.

Sympathetic reactivity in agoraphobic patients with and without personality disorders

OBJECTIVE

To compare sympathetic activity in agoraphobic patients with and without personality disorders before and after 11 weeks inpatient treatment.

METHODS

Agoraphobic patients (n=38), 84% with panic disorder and 47% with personality disorders underwent cold pressure test (CPT), mental stress test (MST), and a specific anxiety test (SAT). Psychological assessments were done by the Bodily Sensations Questionnaire (BSQ), the Agoraphobic Cognitions Questionnaire (ACQ), Spielberger STAI-1 and -2, and a Stress Test Anxiety (STA) questionnaire. Sympathetic activity was measured by blood pressure, heart rate, epinephrine, and norepinephrine.

RESULTS

The sympathetic activity did not differ significantly between patient groups, and the reactivity to stress was very low. The sympathetic reactivity remained unchanged after treatment, whereas psychiatric symptoms decreased. Correlations between sympathetic activity and psychological distress were not significant.

CONCLUSION

Interpretation of bodily signals seems to be more important than the actual sympathetic activity in agoraphobic patients.

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.

Ambulatory blood pressure monitoring in children and adolescents

With recent technological advances, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) has become a useful tool for the evaluation, diagnosis, and management of hypertensive children. It provides a more accurate representation of an individual's BP rather than intermittent casual or office BP measurements. Hence, ABPM is being used more often to assess the BP of children. In this comprehensive review, we provide the reader with the available literature on ABPM, discuss the advantages and limitations of ABPM, and the interpretation of ABPM data. The role of ABPM in various clinical conditions and hypertension research in children is presented.

Prevention of essential hypertension in minority populations

The precursors of essential hypertension (EH) begin in childhood. If the etiology of the evolution of EH were discovered, interventions may be developed to lead to the primary prevention of EH. In particular, one ethnic group, African-Americans (Blacks), are at increased risk of development of EH in adulthood. Hemodynamic changes in response to stressors are termed measures of cardiovascular reactivity (CVR). Ethnic difference in CVR are known to exist; are these markers or mechanisms of EH evolution? Investigations are underway to discover the mechanism(s) of the excessive vasoconstriction which appears to be characteristic of the CVR responses in Blacks. These may lead to the pharmacologic, or non-pharmacologic, interventions which may be initiated in childhood and prevent EH in adults.

Reproducibility of radial pulse wave analysis in healthy subjects

OBJECTIVE

To determine the reproducibility of parameters estimated by pulse wave analysis (PWA), mainly of central systolic blood pressure in the aorta (CSP), central systolic pressure-time index (CSPTI, area under the systolic part of the curve in the pressure-time graph per minute), and central augmentation index (CAI, pressure peak caused by wave reflection divided by pressure peak caused by ventricular ejection).

METHODS

In 88 healthy subjects, aged 19-53 years, radial pulse wave was registered by two investigators on separate visits in a random sequence, twice during each visit

RESULTS

Variability within and among subjects was significantly different for peripheral systolic pressure (PSP) and for all the above-mentioned parameters (P < 0.0001 by ANOVA for all). Variability within and between observers was tested by Bland-Altman plots; they did not show any trend for the variability to be dependent on the underlying mean value. PSP, CSP and CSPTI decreased significantly during one visit (by 4.6, 4.7 and 4.2%, respectively), PSP and CSP were higher at the first than at the second visit (by 2.2, 2.2%, respectively, and not significant for CSPTI), and there were also significant interobserver differences in all the three parameters as one observer measured higher values (by 2.4, 3.2 and 6.0%, respectively). CAI did not change within and between visits; the same applied to the difference between PSP and CSP since these pressures always changed in parallel.

CONCLUSIONS

PWA gives estimates of several parameters characterizing the pressure load of central circulation and the wave reflection. The reproducibility of CSP and CSPTI is similar to that of PSP. CAI and the difference between PSP and CSP is not influenced by order of measurement, of visit or by investigator. Therefore, CAI is a more stable parameter than PSP measured by an oscillometric device. Since these parameters may contribute to a better assessment of cardiovascular risk, PWA might be used in prospective studies.

Relationship between left ventricular mass and hemodynamic responses to physical and mental stress

OBJECTIVE

Increased left ventricular mass (LVM) is predictive of future cardiac morbidity and mortality. Although casual and ambulatory blood pressure (BP) predict LVM, other hemodynamic determinants of LVM are incompletely understood. The present study examines laboratory-induced hemodynamic responses (to exercise, cold, and mental stress) and 24-hour ambulatory measures as predictors of LVM.

METHODS

Thirty-six healthy non-hypertensive subjects (mean age 33.9 +/- 9.4 years; 23 women, 13 men) were tested with mental stress, cold pressor, and treadmill exercise in the laboratory and 24-hour ambulatory BP monitoring. LVM was measured using two-dimensional targeted M-mode echocardiography and indexed for body surface area (LVMI).

RESULTS

All laboratory tasks produced significant hemodynamic responses (p's < 0.01). Systolic blood pressure responses to mental stress (r = 0.42, p < 0.01) and cold pressor (r = 0.34, p < 0.05) were significantly related to LVM. After adjusting for body size, the mental stress-induced SBP responses was the only significant predictor of LVMI (r = 0.32, p < 0.05). Exercise SBP responses were associated to LVMI in men (r = 0.63, p = 0.02), but not in women (r = 0.02, p = n.s.). Multivariate regression analyses revealed that SBP during mental stress was significantly predictive of LVMI (beta = 0.65, p = 0.05), independent of baseline SBP, 24-hour ambulatory SBP, and other control variables.

CONCLUSION

The present results indicate that SBP responses to mental stress are significantly related to LVM among healthy individuals, independently of baseline SBP, 24-hour ambulatory BP, age, body size, and sex. Blood pressure responses to exercise show a robust association with LVM in men but not in women. Hemodynamic responses elicited during laboratory tasks may therefore reveal important information about the pathophysiological processes involved in the development of cardiac end-organ damage.

Genetic and environmental influences on coping styles: a twin study

OBJECTIVE

Coping styles are generally considered to be environmentally driven, primarily by family influences. However, because personality traits are commonly influenced by genetic effects, we hypothesized that heredity is also important for coping.

METHODS

We tested this hypothesis by assessing 19 coping styles, as well as four secondary coping factors, by questionnaire in 212 pairs of monozygotic and dizygotic twins. We then examined heredity by structural equation modeling.

RESULTS

All coping styles showed evidence of genetic influences. The coping styles shared one common genetic factor. In addition, each coping style was also influenced by other separate genetic factors. Shared environment had no significant influence on coping styles. Three of 19 more specific coping styles showed shared environmental effects as well as genetic influences, 14 were solely under genetic influences, and two showed only shared environment effects.

CONCLUSIONS

We suggest that hereditary effects on certain coping style preferences cannot be explained solely by genetic influences on major personality traits and temperament. An analysis of the relationships between coping and personality in twin subjects may elucidate the distinction between genetic and environmental effects.

Cardiovascular stress response and coronary artery disease: evidence of an adverse postmenopausal effect in women

OBJECTIVES

To test the hypothesis that postmenopausal women demonstrate greater vascular instability, measured by enhanced cardiovascular stress responses during mental stress, compared with men and premenopausal women.

BACKGROUND

Recent data suggest that estrogen plays a role in regulating vascular tone. The possible consequences of estrogen deficiency during menopause on systemic vascular reactivity is largely unexplored.

METHODS

One hundred subjects (84 men and 16 women) underwent mental stress testing with radionuclide ventriculo graphy. Study subjects included 19 normal volunteers, 23 control subjects with chest pain syndromes or hypertension but without coronary artery disease, and 58 coronary artery disease subjects. The subjects performed a series of three mental stress tasks, during which hemodynamic data and radionuclide ventriculograms were obtained.

RESULTS

Overall, women demonstrated greater hemodynamic responses during mental stress measured by changes in heart rate, systolic and diastolic blood pressure, and double product compared with those of men (all p < 0.05). Women with coronary artery disease demonstrated greater heart rate, diastolic blood pressure, and double product stress responses than their male counterparts (all p < 0.05). Women of postmenopausal age demonstrated significantly greater systolic blood pressure reactivity than men or premenopausal women (p < 0.05).

CONCLUSIONS

Women of postmenopausal age have greater cardiovascular responses to stress than men or premenopausal women. These findings suggest an additional mechanism by which estrogen deficiency conveys a poor prognosis in female patients with coronary artery disease.

Talking effect and white coat phenomenon in hypertensive patients

Both white coat effect (the tendency of blood pressure to rise during a medical visit) and talking effect were analyzed in 42 patients with essential hypertension. Blood pressure was measured during the clinic visit and over the subsequent 24-hour ambulatory period, with the physician performing 49 +/- 4 measurements for each patient. Three silent periods and two talking periods (stress and relaxation) were randomly allocated in a crossover design and studied, using analysis of variance. During the initial 11-minute silent period, systolic/diastolic blood pressures increased by 6 mm Hg/5 mm Hg. During the subsequent talking periods, these variations were significantly greater: +22 mm Hg/+17 mm Hg. Measures of systolic/diastolic blood pressure were higher during stressful talking than during relaxed talking. The talking and its emotional contents seemed to explain 70% of the white coat phenomenon. To minimize the white coat phenomenon in the clinic, physicians, nurses, and clinicians are advised to measure blood pressure during an initial period of silence.

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

Reproducibilities of blood pressure and heart rate (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 (DBP) (.348). Both SBP and HR response reproducibility was higher at shorter test-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 available 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.

Is white coat hypertension associated with arterial disease or left ventricular hypertrophy?

Although white coat hypertension may be present in 20% or more of hypertensive individuals, its prognostic significance is unknown. We compared prognostically relevant measures of target-organ damage among 24 individuals with white coat hypertension and age- and sex-matched groups of sustained hypertensive and normotensive subjects classified by clinical and 24-hour ambulatory blood pressures. Left ventricular and carotid artery structure and function were evaluated by ultrasonography. Left ventricular mass index was similar in white coat hypertensive (82 +/- 17 g/m2) and normotensive (78 +/- 15 g/m2) subjects but was higher in sustained hypertensive subjects (97 +/- 19 g/m2, P < .02 and P < .002, respectively). Similarly, carotid artery intimal-medial thickness was greater in the sustained hypertensive group (0.98 +/- 0.21 mm) than in the white coat hypertensive (0.84 +/- 0.16 mm, P < .05) and normotensive (0.76 +/- 0.18 mm, P < .001) groups. The prevalence of discrete atherosclerotic plaques was higher in the sustained hypertensive group (58%) than in the white coat hypertensive (25%, P < .05) and normotensive (21%, P < .02) groups. Cardiac and carotid structure in individuals with white coat hypertension resemble findings in normotensive subjects and differ significantly from those in age- and sex-matched sustained hypertensive subjects. These findings suggest that white coat hypertension may be a benign condition for which pharmacological intervention may not be necessary, a hypothesis that needs to be tested in longitudinal studies with clinical end points.

Cardiovascular recovery from laboratory stress: biopsychosocial concomitants in older adults

Although cardiovascular recovery may be important to long term cardiovascular health, its biopsychosocial correlates have received much less attention than the correlates of cardiovascular reactivity. Of the few studies that have examined recovery, fewer still have examined men and women over 60 yr of age. This study examined relationships of psychosocial factors (e.g. state anxiety, anger, avoidance coping, Type A behavior, etc.) with recovery in 186 older married men (n = 63) and women (n = 123) (mean age = 69.7 +/- 6.1 yr). Regressions were performed to explain recovery variability in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) in response to emotional and cognitive tasks. In each analysis, we controlled for the effects of gender, type of task, reactivity to the task, and other important covariates. Individuals with slower recovery had higher scores on anxiety (for SBP, p < 0.03 and DBP, p < 0.01), higher scores on avoidance coping (for DBP and HR, p < 0.01), and lower scores on anger held in (for DBP, p < 0.01). Psychosocial factors may be important in explaining recovery in older adults.

Diagnosis of mild hypertension by ambulatory blood pressure monitoring

BACKGROUND

Between 20% and 30% of patients with clinically diagnosed hypertension have normal blood pressure (BP) values during automated ambulatory 24-hour BP monitoring. It has not been clear, however, whether these patients can be regarded as normotensive or whether they should be treated in the same way as confirmed hypertensive patients.

METHODS AND RESULTS

Ambulatory BP monitoring was performed in 88 normal control subjects and 171 hypertensive patients (office diastolic BP > or = 90 mm Hg on three visits; never treated or off treatment for more than 6 months). Hypertensive patients were classified as nonconfirmed or white coat (n = 58) if their 24-hour diastolic averages were < 85 mm Hg and at least 15 mm Hg lower than their office values. For comparisons, white coat patients were pair-matched with normal subjects by 24-hour diastolic averages and sex, and by similar age and weight; there were 40 such pairs. White coat patients were likewise pair-matched with confirmed hypertensive patients by identical office BPs (51 pairs). Participants were studied by individualized treadmill testing, Doppler echocardiography, and assays of resting plasma catecholamines, upright plasma renin and aldosterone, and lipid, glucose, and insulin concentrations. Because of the matching, compared with normal subjects, patients with white coat hypertension and normal subjects had identical 24-hour BP averages. The white coat patients exhibited slightly greater variability among individual readings (obtained each 15 minutes) throughout the day [P < .05]), but there were no differences in hemodynamic responses to exercise. Plasma norepinephrine (P < .05), renin and aldosterone (P < .01 for each), and insulin and low-density lipoprotein cholesterol levels (P < .01 for each) were higher in the white coat group, as were left ventricular septal wall (P < .05) and muscle mass (P = .07) echocardiographic measurements. When compared with the confirmed hypertensive patients, the white coat patients had higher renin (P < .01) but were otherwise similar. Within the white coat group, plasma norepinephrine correlated with total cholesterol and triglycerides (P < .05 for each), and aldosterone correlated with left ventricular mass (P < .01); there were no significant correlations within the normal control subject or confirmed hypertension groups.

CONCLUSIONS

Patients with white coat hypertension differ in metabolic, neuroendocrine, and cardiac findings from normal control subjects and have greater BP variability. These changes appear to be mediated by heightened activity of the sympathetic and renin-angiotensin systems. Although these characteristics could reflect an alerting reaction in the clinic due to awareness of their diagnosis, the white coat hypertensive patients also have evidence for additional, more-sustained differences from normal subjects. Thus, this condition appears to be a true variant of hypertension.

Augmentation of baroreceptor reflex function by oral calcium supplementation in essential hypertension

1. We studied the effect of oral calcium supplementation (1.0 g/day) for 1 week on baroreceptor reflex function and the lability of blood pressure in association with the changes in autonomic nervous activity in 14 hospitalized patients with mild to moderate essential hypertension (nine males and five females, mean age of 56 +/- 11.2 (s.d.) years). 2. Baroreceptor reflex sensitivity (BRS) was determined by the change in R-R intervals in response to the pressor response induced by phenylephrine injection. We measured coefficient of variation of R-R interval (CVR-R) and urinary excretion of catecholamines to evaluate the mechanism of change in BRS. We also used coefficient of variation of blood pressure (CVBP) and error of single cosinor analysis as parameters for lability of 24-h blood pressure. 3. The means of 24-h systolic and diastolic blood pressures showed no significant changes after calcium supplementation for 1 week. BRS and CVR-R were significantly increased by calcium supplementation. Daily excretions of norepinephrine and epinephrine corrected by creatinine were unchanged. Both CVBP and error of 24-h systolic blood pressure showed a significant decrease after calcium treatment. 4. These results indicate that oral calcium supplementation augments baroreceptor reflex function, in part through an enhancement of parasympathetic nervous activity, resulting in reduction of the lability of blood pressure in patients with mild to moderate essential hypertension.

Serum lipids, neuroendocrine, and cardiovascular responses to stress in men and women with mild hypertension

In this study, we examined the relation between serum lipid levels, gender, and cardiovascular and neuroendocrine stress reactivity in patients with mild hypertension. Ninety-nine individuals (62 men, 37 women) with mild hypertension performed four mental stress tasks: mental arithmetic, public speaking, cold stress, and a computer videogame. Cardiovascular reactivity scores were computed by subtracting the minimum resting blood pressure (BP) and heart rate (HR) values from the maximum values obtained during each task. Neuroendocrine reactivity was calculated as the change from epinephrine and norepinephrine values from mean rest to mean task. High and low reactors were identified on the basis of median splits of reactivity scores, averaged across all four stressors. High systolic blood pressure reactors had higher levels of total (TC), low-density lipoprotein cholesterol (LDL-C), and apo-B than did low reactors. High diastolic blood pressure reactors had lower levels of high-density lipoprotein cholesterol (HDL-C) and higher levels of LDL-C and apo-B than did low reactors. High HR reactors had higher apo-AI:apo-AII ratios than low reactors. Lipid levels were not different for high and low epinephrine and norepinephrine reactors. Although women were noted to have more favorable lipid profiles than men, both male and female hypertensive patients who were high reactors had less favorable lipid profiles than low reactors.

Cardiovascular reactivity, coronary risk factors, and sympathetic activity in young men

We have previously demonstrated that awareness of high blood pressure may increase blood pressure, plasma catecholamine levels, and stress responses. In the present study, three groups of 19-year-old men, all unaware of their blood pressure status, were selected from the first (group-1, 62 +/- 2 mm Hg, [mean +/- SEM], n = 15), 50th (group-50, 90 +/- 4 mm Hg, n = 15), and 99th (group-99, 123 +/- 5 mm Hg, n = 14) percentiles in causal mean blood pressure at a screening. They were studied (blinded examiners) with intra-arterial blood pressure recordings and multiple measurements of arterial plasma epinephrine and norepinephrine during a mental arithmetic challenge and cold pressor test. Despite high mean blood pressure at the screening, group-99 did not differ from group-50 either in intra-arterial mean blood pressure after 30 minutes of supine rest (89 +/- 3 versus 86 +/- 2 mm Hg) or in serum lipids and resting plasma epinephrine and norepinephrine. However, in group-99 resting plasma epinephrine showed a positive hyperbolic relation to resting diastolic blood pressure (r = .73, P = .004) and a negative hyperbolic relation to the ratio of high-density lipoprotein cholesterol to total cholesterol (r = -.75, P = .002). None of these correlations were present in the two other groups. Furthermore, the three groups differed in heart rate responses (P < .0005) and systolic (P < .0005) and diastolic (P < .05) blood pressure responses to mental arithmetic challenge, group-99 being hyperreactive compared with the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Self blood pressure measurement at home

Forty-six untreated patients measured their blood pressure at home for three weeks using an A and D, UA 751 automatic device, and were examined three times at the outpatient clinic. Home blood pressure was significantly lower than clinic blood pressure, even at the third visit when the correlations between clinic and home values were the most significant. The differences between clinic and home values had a gaussian distribution. The variance analysis of home blood pressure values showed that 67% of the variance was attributable to the between-subject component, 2% to the day effect, 15% to the time of the day effect and 16% to the residual (the measurement error). The standard deviation of the difference between two five-day periods of self blood pressure monitoring at home (5.4 and 4.1 mm Hg) was much lower than what has been reported for clinic measurements or 24-hour ambulatory monitoring.

Blood pressure responses after carotid surgery: relationship to postoperative baroreceptor sensitivity

BACKGROUND AND PURPOSE

Among hypertensive patients after carotid surgery, a group of patients with increased baroreflex sensitivity was identified. In the other group of hypertensive patients, blood pressure and reflex sensitivity were unchanged postoperatively. We hypothesized that a partial readjustment of baroreceptor sensitivity would produce more stable blood pressure profiles.

METHODS

In order to test this hypothesis, a prospective, long-term follow-up study was designed. Blood pressure was monitored in 18 hypertensive and 6 normotensive patients during 6 months using a self-measurement technique. In addition, continuous 24-hour blood pressure monitoring was performed 6 months after surgery. The mean values and the ranges (amplitudes) of systolic and diastolic blood pressure were calculated as indicators for the stability of the circulatory system.

RESULTS

Hypertensive patients with unchanged postoperative baroreceptor sensitivity showed significantly more pronounced instabilities of their blood pressure profiles (amplitudes of systolic and diastolic blood pressure p < 0.05 to p < 0.001). A relationship between baroreceptor function and antihypertensive therapy could also be demonstrated, with adequate therapy being much more difficult in patients with reduced or unchanged baroreceptor sensitivity.

CONCLUSIONS

In contrast to vascular surgery on the aorta or in the region of the lower limbs, carotid surgery is frequently associated with blood pressure changes, demonstrating the essential role of the baroreceptors in the carotid sinus for the regulation of postoperative blood pressure. Since it seems to be the variability of blood pressure, and not the blood pressure level alone, that is critical, close blood pressure monitoring--allowing for an assessment of blood pressure variability--appears to be of particular importance in such patients.

Serum lipids, neuroendocrine and cardiovascular responses to stress in healthy Type A men

This study examined the relationship between serum lipid activity in healthy Type A men and cardiovascular and neuroendocrine responses to a behavioral stressor, mental arithmetic. Assessment of blood lipids included measures of total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and serum triglycerides. Cardiovascular (blood pressure and heart rate) and neuroendocrine (epinephrine, norepinephrine and cortisol) responses were recorded before (rest), during (stress) and after (recovery) the mental arithmetic test. Diastolic blood pressure, mean arterial pressure and, to a lesser extent, systolic blood pressure levels at rest, during stress, and at recovery correlated positively with TC levels. In addition, both diastolic and mean arterial pressure were positively correlated with the ratio of TC to HDLC and with triglycerides during stress and recovery. Heart rate did not correlate with any lipid measure. Cardiovascular stress-reactivity calculated as change from rest to stress did not correlate significantly with any lipid measure. Plasma norepinephrine during stress correlated positively with triglycerides; a similar trend was observed for the TC/HDLC ratio. Plasma cortisol at rest and during stress correlated positively with the TC/HDLC ratio and serum triglycerides, and negatively with HDLC. Plasma norepinephrine reactivity calculated as change from rest to stress correlated negatively with HDLC and positively with triglycerides. In addition, cortisol reactivity was positively correlated with triglycerides. It is suggested that the mechanisms mediating Type A behavior and coronary heart disease may include increased cardiovascular and neuroendocrine responses as well as unfavorable lipid profiles.

Clinical utility of ambulatory blood pressure monitoring in target organ complications and equipment choices

Although population studies have demonstrated a relationship between casual office blood pressures and target organ events, the variability of these blood pressure measurements for individual patients has generated an interest in the role of ambulatory blood pressure monitoring for defining the presence of hypertension and assessing the response to therapy. Noninvasive devices provide fewer data than intra-arterial ambulatory blood pressure monitoring devices, but are safer. No current noninvasive device performs well during ambulation. Rigorous evaluation of these rapid proliferating electronic devices is important, as would be the case with any new antihypertensive agent. Although ambulatory blood pressure measurements correlate better with target organ damage for groups of patients than do casual office measurements, the predictability and limited data on reproducibility for individual patients does not support widespread application for routine testing for hypertensive patients. Ambulatory blood pressure monitoring should be viewed as a standard research tool for the evaluation of new cardiovascular drugs.