Role of cardiovascular reactivity to mental stress in predicting future hypertension

Effect of Psychosocial Distress on the Rate of Kidney Function Decline

BACKGROUNDS

Chronic kidney disease is a growing global health problem. Psychosocial stress has been found to induce changes in biological processes and behavioral patterns that increase risks of cardiovascular and metabolic diseases. However, the association between psychosocial stress and kidney function is not well understood.

OBJECTIVE

To evaluate the association between psychosocial stress and kidney function decline.

DESIGN

In this prospective cohort study, psychosocial distress was assessed using the psychosocial well-being index short-form (PWI-SF).

PARTICIPANTS

Data of a total of 7246 participants were retrieved from a community-based cohort (Korean Genome and Epidemiology Study).

MAIN MEASURES

The rate of estimated glomerular filtration rate (eGFR) decline was calculated for each individual. Rapid eGFR decline was defined as a decrease of ≥ 3 mL/min/1.73 m² per year. The presence of kidney disease was defined as eGFR < 60 mL/min/1.73 m² at baseline or proteinuria of higher than trace levels from two consecutive urine test results.

KEY RESULTS

A total of 7246 participants were analyzed. The mean eGFR was 92.1 ± 14.0 mL/min/1.73 m². Rapid eGFR decline was observed in 941 (13.0%) participants during a median follow-up of 11.7 years. When the participants were categorized into tertiles according to PWI-SF score, rapid eGFR decline was more prevalent in the group with the highest PWI-SF score (15.8%) than in the group with the lowest score (12.2%). Multivariate logistic regression analysis revealed that the risk of rapid eGFR decline was significantly increased in the tertile group with the highest PWI-SF score compared to the lowest group (odds ratio, 1.35; 95% confidence interval, 1.15-1.59). This association was maintained even after adjusting for confounding variables and excluding participants with kidney disease.

CONCLUSIONS

Higher levels of psychosocial distress were closely associated with an increased risk of rapid kidney function decline.

Cerebrovascular function in hypertension: Does high blood pressure make you old?

The majority of individuals over an age of 60 have hypertension. Elevated blood pressure and older age are associated with very similar changes in brain structure and function. We review the parallel brain changes associated with increasing age and blood pressure. This review focuses on joint associations of aging and elevated blood pressure with neuropsychological function, regional cerebral blood flow responses to cognitive and metabolic challenges, white matter disruptions, grey matter volume, cortical thinning, and neurovascular coupling. Treatment of hypertension ameliorates many of these changes but fails to reverse them. Treatment of hypertension itself appears more successful with better initial brain function. We show evidence that sympathetic and renal influences known to increase blood pressure also impact brain integrity. Possible central mechanisms contributing to the course of hypertension and aging are then suggested. An emphasis is placed on psychologically relevant factors: stress, cardiovascular reactions to stress, and diet/obesity. The contribution of some of these factors to biological aging remains unclear and may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.

Reduced emotional responsiveness in individuals with marginal elevation in blood pressure within the normal range: Evidence from altered affect-modulated startle response

Reduced responsiveness to emotional stimuli ('emotional dampening') has been observed in normotensives with elevated blood pressure (BP) and hypertensives but it is not known whether this is due to aberrant responding to emotional information at the involuntary level and whether it is also associated with minimal elevations in BP in the normal range. In this study, we examined emotional dampening using the affect-modulated startle paradigm given its proven sensitivity to motivational states of approach and withdrawal, typically independent of conscious intentional control. Acoustically elicited startle eye-blink modulation was measured using electromyography of the orbicularis oculi muscle beneath the left eye in 59 healthy individuals while they viewed pleasant, unpleasant and neutral standardized pictures. The expected startle attenuation to pleasant pictures, and startle potentiation to unpleasant pictures, relative to neutral pictures, was found in people in the comparison (N = 29) but not elevated BP (N = 30) group. This finding was further supported by significant moderating effect (assessed using ANCOVA and sub-sample analysis) of BP on valence-startle amplitude relationship. The comparison BP group also showed slower latencies to response onset for pleasant stimuli compared to neutral and unpleasant, with no effect of valence in the elevated BP group. However, BP did not moderate the valence-onset latency relationship. Our findings indicate that previously reported emotional dampening associated with elevated BP extends to reduced involuntary emotional reactivity and to individuals with even minimal BP elevations (i.e. higher but still within the normal range). Future research needs to confirm these findings in hypertensive individuals, preferably using within-subjects designs.

[Risk of high blood pressure in hyperreactive cardiovascular individuals.]

OBJECTIVE

To determine the risk of high blood pressure in cardiovascular hyperreactive individuals identified by the isometric hand-held weight test.

MATERIALS AND METHODS

A prospective cohort study was conducted for 5 years, including a total of 419 individuals. Of them, 215 were normoreactive and 204 hyperreactive. The relative risk of hypertension in the hyperreactive individuals and the contribution of cardiovascular hyperreactivity to the development of high blood pressure were determined. The significance level was 0.05.

RESULTS

The frequency of new hypertension cases after five years was twice as high in the cohort of hyperreactive subjects compared to the cohort of normoreactive subjects (RR 2.23, 95%CI 1.42, 3.51). The cardiovascular hyperreactivity was the most important variable for predicting of the high blood pressure (OR: 2.73; 95%CI 1.59, 4.54).

CONCLUSIONS

Conclusions. Cardiovascular hyperreactive individuals have a higher risk of high blood pressure than normorreactive individuals.

Activation of melanocortin receptors in the intermediolateral cell column of the upper thoracic cord elicits tachycardia in the rat

Melanocortin receptors (MCRs) are present in the intermediolateral cell column of the spinal cord (IML). We tested the hypothesis that activation of MCRs in the IML elicits cardioacceleratory responses and the source of melanocortins in the IML may be the melanocortin-containing neurons in the hypothalamic arcuate nucleus (ARCN). Experiments were done in urethane-anesthetized, artificially ventilated adult male Wistar rats. Microinjections (50 nl) of α-melanocyte stimulating hormone (α-MSH) (0.4-2 mM) and adrenocorticotropic hormone (ACTH) (0.5-2 mM) into the right IML elicited increases in heart rate (HR). These tachycardic responses were blocked by microinjections of melanocortin receptor 4 (MC4R) antagonists [SHU9119 (0.25 mM) or agouti-related protein (AGRP, 0.1 mM)] into the right IML. Stimulation of right ARCN by microinjections (30 nl) of N-methyl-d-aspartic acid (NMDA, 10 mM) elicited increases in HR. Blockade of MC4Rs in the ipsilateral IML at T1-T3 using SHU9119 (0.25 mM) attenuated the tachycardic responses elicited by subsequent microinjections of NMDA into the ipsilateral ARCN. ARCN neurons retrogradely labeled by microinjections of Fluoro-Gold into the right IML showed immunoreactivity for proopiomelanocortin (POMC), α-MSH, and ACTH. Fibers immunoreactive for POMC, α-MSH, and ACTH were present in the IML at T1-T3. These results indicated that activation of MC4Rs in the right IML elicited tachycardia and one of the sources of melanocortins in the IML is the ARCN. Melanocortin levels are elevated in stress and ARCN neurons are activated during stress. Our results allude to the possibility that cardiac effects of stress may be mediated via melanocortin containing ARCN neurons that project to the IML.

Mechanisms of cardiovascular actions of urocortins in the hypothalamic arcuate nucleus of the rat

The presence of urocortins (UCNs) and corticotropin-releasing factor (CRF) receptors has been reported in the hypothalamic arcuate nucleus (ARCN). We have previously reported that UCNs are involved in central cardiovascular regulation. Based on this information, we hypothesized that the ARCN may be one of the sites where UCNs exert their central cardiovascular actions. Experiments were done in artificially ventilated, adult male Wistar rats anesthetized with urethane. Unilateral microinjections (30 nl) of UCN1 (0.12-2 mM) elicited decreases in mean arterial pressure (MAP) and heart rate (HR). Maximum cardiovascular responses were elicited by a 1 mM concentration of UCN1. Microinjections of UCN2 and UCN3 (1 mM each) into the ARCN elicited similar decreases in MAP and HR. UCN1 was used as a prototype for the other experiments described below. HR responses elicited by UCN1 were significantly attenuated by bilateral vagotomy. Prior microinjections of NBI-27914 (CRF-1 receptor antagonist) and astressin (CRF-1 receptor and CRF-2 receptor antagonist) (1 mM each) into the ARCN significantly attenuated the cardiovascular responses elicited by UCN1 microinjections at the same site. Microinjections of UCN1 into the ARCN decreased efferent renal sympathetic nerve activity. It was concluded that microinjections of UCN1, UCN2, and UCN3 into the ARCN elicited decreases in MAP and HR. Decreases in MAP, HR, and renal sympathetic nerve activity elicited by UCN1 microinjections into the ARCN were mediated via CRF receptors. Bradycardic responses to UCN1 were mediated via the activation of vagus nerves, and decreases in MAP may be mediated via decreases in sympathetic nerve activity.

Pro-inflammatory cytokine levels in postmenopausal women with the metabolic syndrome

BACKGROUND

Prevalence of the metabolic syndrome (METS) and its components significantly increase after the menopause. Related increased cardiovascular risk may partially be explained by a pro-inflammatory state.

OBJECTIVE

To assess pro-inflammatory cytokine serum levels in postmenopausal women with and without the METS.

METHODS

Serum of 90 postmenopausal women who previously participated in a METS screening programme was analysed for tumour necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6). Cytokine levels were compared among those with and without the syndrome, and for each of its components. Linear relationships were also assessed between cytokine levels and several continuous variables including each diagnostic METS criteria and menopausal symptoms assessed with the Menopause Specific Quality of Life tool (MENQOL).

RESULTS

For all studied women mean age was 55.1 ± 7.3 years with 63.3% having abdominal obesity, 15.6% hyperglycaemia, 58.9% high triglycerides, 44.4% hypertension and 25.6% high total cholesterol levels. Women with the METS (n = 45) significantly had higher body mass index values, and higher rates of abdominal obesity, hyperglycaemia, hypertriglyceridemia, hypertension and lower HDL-C levels. Cytokine levels did not differ among women with or without the METS; however, independent of METS diagnosis those with abdominal obesity displayed significantly higher IL-6 levels and those with hypertension higher levels of both cytokines. Levels of both cytokines positively correlated with age and time since menopause, IL-6 positively correlating with waist circumference values and TNF-α positively with both systolic and diastolic blood pressure levels. A significant positive correlation was also found between the number of positive METS criteria (0-5) and both cytokine levels. Cytokine levels did not correlate with vasomotor and psycho-social MENQOL scores.

CONCLUSION

Pro-inflammatory cytokine levels in this postmenopausal series positively correlated with age, time since the menopause, abdominal circumference, blood pressures levels and the number of positive METS diagnostic criteria. There is a need for more research in this regard.

Effects of estrogen plus progesterone on hemodynamic and vascular reactivity in hypertensive postmenopausal women

AIMS

To investigate the medium-term effects of estrogen plus progesterone therapy (EPT) on vascular reactivity, endothelial function and hemodynamic responses in 20 hypertensive postmenopausal women.

METHODS

This randomized, double-blind, cross-over, placebo-controlled study investigates the effect of 6 months of EPT (conjugated equine estrogen plus medroxyprogesterone). Blood pressure (office and ambulatory), heart rate and heart rate variability (HRV) were measured at baseline and following EPT/placebo treatment. In eight women, we used a wire-myograph to assess endothelial function and contractile response of subcutaneous arteries to transmural nerve stimulation (TNS) and exogenous noradrenaline.

RESULTS

EPT decreased vascular reactivity to cumulative TNS compared with baseline (p<0.01) and placebo (p<0.05). Moreover, EPT diminished sensitivity to exogenous noradrenaline (p<0.05). Although EPT reinforced response to acetylcholine, we observed no difference in maximal relaxation induced by substance P or acetylcholine. EPT did not affect ambulatory blood pressure, heart rate or HRV.

CONCLUSIONS

Oral combined medium-term EPT reduces adrenergic reactivity in subcutaneous arteries from treated hypertensive postmenopausal women. EPT might act postjunctionally at the adrenergic vascular receptor level. In the present study, EPT neither reduces sympathetic activity nor increases vagal tone, and thus does not support an effect on the central hemodynamic system.

Depression and the cardiovascular system: increasing evidence of a link and therapeutic implications

This review explores the epidemiological evidence for the relationship between depression and cardiovascular disease from a mechanistic standpoint. It is important to examine the biological, behavioral and social mechanisms to improve outcomes for depressed cardiac patients. A number of plausible biobehavioral mechanisms linking depression and cardiovascular disease have been identified. Tricyclic antidepressants have various effects on the cardiovascular system, while selective serotonin reuptake inhibitors are not associated with adverse cardiac effects and should, therefore, be the preferred choice for the treatment of most patients with comorbid depression and cardiovascular disease.

[Sympatho-vagal balance and cardiac response to mental challenge]

BACKGROUND

Based on functional relations between the central autonomic network and cortical areas involved in motivational, attentional, affective, and executive function, autonomic regulation can mediate cognitive performance as well as cardiovascular and psychosomatic diseases. Our objective was to test the predictive value of resting heart rate variability (HRV), a measure of sympatho-vagal balance, with regard to the type and intensity of cardiovascular responses to mental challenge.

MATERIALS AND METHODS

A total of 248 healthy subjects (85 females, aged 47.3+/-7.6 years; 163 males, aged 47.5+/-6.7 years) were included in the study. All participants underwent standardized psychometric testing (e.g., Stroop's color-word-conflict test).

RESULTS

First, we found significant increases of heart rate and sympatho-vagal balance (low frequency/high frequency) and significant decreases of absolute LF- and HF-power in response to mental tasks. Second, there were significant differences in cardiovascular response to mental challenge when clustering our population on the basis of sympatho-vagal balance at rest.

CONCLUSIONS

We conclude that short-term recordings of HRV can provide health-related information of cardio-vascular response to mental challenge. However, there is no association between sympatho-vagal balance at rest and classical cardiovascular risk factors.

Orienting-Defense Responses and Psychophysiological Reactivity in Isolated Clinic versus Sustained Hypertension

This study sought to determine whether patients with white-coat or isolated clinic hypertension (ICH) show, in comparison to patients with sustained hypertension (SH), a defense response pattern to novel stimuli and an enhanced psychophysiological reactivity to stress. Forty-three patients with essential hypertension were divided into two groups after 16 days of self-monitoring blood pressure (BP): ICH (24 men; self-measured BP < 135/85 mmHg) and SH (19 men; self-measured BP >or= 135/85 mmHg). Defense responses were measured as the cardiac changes to phasic non-aversive auditory stimuli. Psychophysiological reactivity (heart and breath rate, blood volume pulse, electromyography, and skin conductance) was measured during mental arithmetic and video game tasks. The standard deviation of self-measured BPs and the difference between mean BPs at work and at home were used as indicators of cardiovascular reactivity to daily stress. No significant differences were seen in defense responses or psychophysiological reactivity to laboratory or naturally occurring stressors. These results do not support the hypothesis that ICH can be explained in terms of a generalized hyperreactivity to novel or stressful stimuli.

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.

Resiliency, stress appraisal, positive affect and cardiovascular activity

In accordance with the undoing hypothesis (Fredrickson, Levenson, 1998), evoked positive affect speeds up the cardiovascular system recovery in a stressful situation. An attempt was made to replicate this finding in an experimental study. Individuals characterized by high resiliency levels are capable of more efficient utilization of positive emotions in a stressful situation. Since in earlier research no relationship had been found between resiliency and a tendency to appraise stress as a challenge, this study investigated a possible mediating function of a more specific dimension of cognitive appraisal, i.e. that in terms of activity-oriented challenge appraisal (Włodarczyk, Wrześniewski, 2005). The study shows that evoked positive affect does not lead to a faster recovery. However, highly resilient individuals turned out to achieve higher levels of positive affect in a stressful situation; this effect was mediated by challenge-activity appraisals.

Stress, depression and cardiovascular dysregulation: a review of neurobiological mechanisms and the integration of research from preclinical disease models

Bidirectional associations between mood disorders and cardiovascular diseases are extensively documented. However, the precise physiological and biochemical mechanisms that underlie such relationships are not well understood. This review focuses on the neurobiological processes and mediators that are common to both mood and cardiovascular disorders. The discussion places an emphasis on the role of exogenous stressors in addition to: (a) neuroendocrine and neurohumoral changes involving dysfunction of the hypothalamic-pituitary-adrenal axis and the activation of the renin-angiotensin-aldosterone system, (b) immune alterations including activation of pro-inflammatory cytokines, (c) autonomic and cardiovascular dysregulation including increased sympathetic drive, withdrawal of parasympathetic tone, cardiac rate and rhythm disturbances, and altered baroreceptor reflex function, (d) central neurotransmitter system dysfunction involving the dopamine, norepinephrine and serotonin systems, and (e) behavioral changes including fatigue and physical inactivity. The review also discusses experimental investigations using preclinical disease models to elucidate the neurobiological mechanisms underlying the link between mood disorders and cardiovascular disease. These include: (a) the chronic mild stress model of depression, (b) a model of congestive heart failure, (c) a model of cardiovascular deconditioning, (d) pharmacological manipulations of body fluid and sodium balance, and (e) pharmacological manipulations of the central serotonergic system. In combination with an extensive human research literature, the investigation of mechanisms underlying mood and cardiovascular regulation using animal models will enhance understanding the association between depression and cardiovascular disease. This will ultimately promote the development of better treatments and interventions for individuals with co-morbid psychological and somatic pathologies.

The potential anti-inflammatory benefits of improving physical fitness in hypertension

Hypertension is associated with an increased risk of stroke and atherosclerosis. In addition to elevated blood pressure, hypertension is characterized by neuroendocrine and immune activation, including elevated levels of C-reactive protein, inflammatory cytokines, and soluble adhesion molecules, which are predictive of morbidity and mortality outcomes. Pharmacological treatment for hypertension reduces blood pressure, but has limited effectiveness in reducing the accompanying inflammation and its associated morbidity and mortality. Exercise and diet interventions regularly show reductions in blood pressure in hypertensive individuals. Similar interventions in other populations show reductions in many inflammatory markers, but these effects have not been routinely examined in hypertensive individuals. The mechanisms through which exercise might exert an anti-inflammatory action include the sympathetic nervous system, the hypothalamic-pituitary-adrenal axis, as well as direct effects of blood pressure. Here, exercise is promoted as a potentially effective treatment for both the elevated blood pressure and chronic inflammation found in hypertension.

Coping, affect, and the metabolic syndrome in older men: how does coping get under the skin?

The metabolic syndrome is a complex construct with interrelated factors of obesity, blood pressure, lipids, and glucose. It is a risk factor for a number of chronic diseases in late life. This study tested a model in which the relationship between stress and the metabolic syndrome was mediated by appraisal, coping, and affect. Data were collected from 518 male participants in the Normative Aging Study (X(age) = 68.17 years). The model was partially confirmed. Relationships among stress, appraisal, coping, and affect were valenced along positive and negative pathways. However, affect was not directly related to the metabolic syndrome. The metabolic syndrome was related to positive coping as operationalized by self-regulatory strategies. The results of this study suggest that the influence of coping on physical health may occur through emotional regulation.

Sympathetic and angiotensin-dependent hypertension during cage-switch stress in mice

The goal of this study was to determine the dependence of the acute hypertensive response to a novel model of acute psychosocial stress on the sympathetic and renin-angiotensin systems. Baseline mean arterial pressure (MAP), heart rate (HR), and locomotor activity were measured with telemetry in mice for a 1-h period and averaged 98 ± 1 mmHg, 505 ± 3 beats/min, and 5 ± 1 counts, respectively. Stress was induced by placing a mouse into a cage previously occupied by a different male mouse, and this increased MAP, HR, and activity in the control group by 40 ± 2 mmHg, 204 ± 25 beats/min, and 68 ± 6 counts, respectively. Each variable gradually returned to baseline levels by 90 min after beginning cage switch. Pretreatment with terazosin (10 mg/kg ip) significantly reduced the initial increase in MAP to 12 ± 6 mmHg, whereas MAP for the last 45 min was superimposable on control values. Atenolol (10 mg/ml drinking water) had no effect to blunt the initial increase in MAP but had a growing effect from 10 min onward, decreasing MAP all the way to baseline by 60 min after starting cage switch. Captopril (2 mg/ml drinking water) treatment caused a very similar response. All three treatments significantly decreased the area under the blood pressure curve, and the blood pressure effect could not be attributed uniformly to effects on HR or activity. These data suggest that our novel model of psychosocial stress causes an initial α1-receptor-dependent increase in MAP. The later phase of the pressor response is blocked similarly by a β1-receptor antagonist and an ACE inhibitor, independent of HR, suggesting that the β1-dependent blood pressure effect is due, in large part, to the renin-angiotensin system.

Hiperreactividad cardiovascular en pacientes con antecedentes familiares de hipertensión arterial

BACKGROUND AND OBJECTIVE

The association between family history of essential high blood pressure (FH of HBP) and the cardiovascular hyperactivity to the isometric exercise is not well known; that is why the aim of this study was to describe this relation and to determine whether it is independent of the presence of cardiovascular risk factors.

PATIENTS AND METHOD

We carried out a correlational descriptive study with a sample of 1855 people of both sexes between 18 and 70 years of age. The cardiovascular hyperactivity, expression of the cardiovascular response to the activity of the sympathetic nervous system (SNS), was determined by means of the test of the sustained weight (TSW). Comparisons of the values of cardiovascular reactivity were developed between individuals with and without FH of HBP and a model of logistical regression. The level of statistical significance was 95%.

RESULTS

The arterial blood pressure at the end of the TSW was higher in individuals with FH of HBP independently of the age group. The cardiovascular hyperactivity, measured by means of they systolic index of cardiovascular reactivity, was also significantly higher in subjects with FH of HBP. Finally, individuals with FH of HBP showed a higher risk (more than 5 times) of having cardiovascular hyperactivity (OR = 5.16; CI 95%, 3.51-7.59), this association being independent of other cardiovascular factors of risk.

CONCLUSIONS

The FH of HBP is independently related to the cardiovascular hyperactivity, to the isometric exercise, of other cardiovascular risks factors. These elements help explain the relationship between cardiovascular hyperactivity, the activity of SNS and essential high blood pressure, at least in an important group of people.

Hypertensive response to acute stress is attenuated in interleukin-6 knockout mice

This study tested the hypothesis that the inflammatory cytokine, interleukin-6, contributes to the hypertensive response to acute psychosocial stress, caused by switching male mice to a cage previously occupied by a different male mouse. Male C57BL6 (WT) and interleukin-6 (IL-6) knockout (KO) mice were implanted with biotelemetry devices to monitor mean arterial pressure, heart rate, and motor activity in the unrestrained state. Baseline mean arterial pressure was 98+/-1 and 103+/-1 for WT and IL-6 KO mice. Cage switch increased mean arterial pressure by 42+/-2 mm Hg in WT mice, but this was blunted significantly in KO mice (31+/-3 mm Hg peak increase). Area under the curve for the first 90 minutes also was significantly less. Heart rate and motor activity increased similarly, and there also were no differences in the increases in plasma renin activity or plasma norepinephrine concentration between WT and KO mice. Thus, the acute hypertensive response to psychosocial stress depends significantly on IL-6, and the effect appears to be specific for blood pressure rather than to a global impairment in the response to stress. However, because perfusion of the isolated mesenteric bed with phenylephrine and chronic infusion of angiotensin II caused similar responses in WT and IL-6 KO mice, it is clear that future studies are needed to determine to what extent the acute blood pressure effect of IL-6 is stress-specific.

Blood pressure reactivity to mental stress task as a determinant of sustained hypertension after 5 years of follow-up

Previous studies have reported an increased risk of developing sustained hypertension (SH) in borderline or mildly hypertensive subjects showing an exaggerated response of blood pressure (BP) to mental stress. The aim of this study was to assess if the response of BP to mental stress tasks is an independent predictor of SH. A total of 89 patients with grade 1 hypertension, aged 18-64 years, 62% males, were included. The mean of follow-up was 5.3 years (s.d. 2.1 years). SH was defined as the development of grades 2-3 hypertension (Systolic BP>or=160 mmHg or diastolic BP>or=100 mmHg) or to be in antihypertensive treatment after follow-up. Two mental stress tasks: mental arithmetic stress task and a stressful interview (SI) were applied at entry. The subjects were classified as hyper-reactors when BP increase was greater than 35 mmHg for systolic BP or greater than 21 mmHg for diastolic BP, according to the results obtained previously in a normotensive control group. In the univariate analysis, the factors associated with the development of SH were age (P=0.0007), office diastolic BP (P=0.014) and hyper-reactivity of BP during a stressful interview (P=0.003). In the Cox regression model, after adjusting for gender, age, and office BP, the hyper-reactivity of BP during SI was an independent predictor of development of SH. In conclusion, the response of BP to mental stress tasks is useful in predicting SH in young and middle-aged subjects with grade 1 hypertension.

Biological mechanisms in the relationship between depression and heart disease

Psychological depression is shown to be associated with several aspects of coronary artery disease (CAD), including arrhythmias, myocardial infarction, heart failure and sudden death. The physiological mechanisms accounting for this association are unclear. Hypothalamic-pituitary-adrenal dysregulation, diminished heart rate variability, altered blood platelet function and noncompliance with medial treatments have been proposed as mechanisms underlying depression and cardiovascular disease. Recent evidence also suggests that reduced baroreflex sensitivity, impaired immune function, chronic fatigue and the co-morbidity of depression and anxiety may be involved in the relationship between depression and cardiovascular dysregulation. An experimental strategy using animal models for investigating underlying physiological abnormalities in depression is presented. A key to understanding the bidirectional association between depression and heart disease is to determine whether there are common changes in brain systems that are associated with these conditions. Such approaches may hold promise for advancing our understanding of the interaction between this mood disorder and CAD.