Platelets, coronary heart disease, and stress

Role of sudarshan kriya and pranayam on lipid profile and blood cell parameters during exam stress: A randomized controlled trial

BACKGROUND

Yoga is a science practiced in India over thousands of years. It produces constituent physiological changes and has sound scientific basis.

AIM

Since exam stress modifies lipid profile and hematological parameters, we conducted an investigation on the effect of sudarshan kriya (SK and P) program on these parameters.

MATERIALS AND METHODS

Blood samples of 43 engineering students were collected at four intervals namely baseline (BL), exam stress (ES), three and six weeks practice of SK and P during exam stress. Lipid profile and hematological parameters were measured at all four intervals.

RESULTS

ES elevated total cholesterol (TC), triglycerides (TGL) and very low density lipoprotein (VLDL) levels. Hematological parameters affected by ES included neutrophil, lymphocytes, platelet count, packed cell volume (PCV) and mean cell volume (MCV). Three and six weeks practice of SK and P reduced the elevated lipid profile, hematological parameters and improved lymphocyte levels.

CONCLUSION

Our study indicates that SK and P practice has the potential to overcome ES by improving lipid profile and hematological parameters.

Acute psychological stress as a precipitant of acute coronary syndromes in patients with undiagnosed ischemic heart disease: a case report and literature review

OBJECTIVES

Acute psychological stress causes a number of physiologic responses that can trigger acute coronary syndromes in individuals with silent coronary artery disease. The mechanisms behind this phenomena have been the subject of much speculation. The following is a case report and brief review of the literature.

METHOD

A PubMed search was undertaken using the key words stress and myocardial infarction, stress and ischemia, mental stress and coronary artery disease, psychological stress and acute coronary syndrome, and mental stress and plaque destabilization. Articles were restricted to the English language and those dating through December 2007.

RESULTS

Acute coronary syndrome is thought to be the end result of a complex mechanism involving platelet activation and endothelial dysfunction. Several studies have shown that acute mental stress leads to enhanced platelet activation and endothelial dysfunction. The mechanism behind this involves both the autonomic nervous system and the neuroendocrine response.

CONCLUSIONS

Acute psychological stress may lead to acute coronary syndromes in patients with previously silent disease. Physicians should inquire about cardiac symptoms in patients with cardiac risk factors who are experiencing psychological distress. Further research will hopefully lead to an improved understanding of the mechanism behind this process to improve therapeutic interventions.

Hemoconcentration and hemostasis during acute stress: interacting and independent effects

BACKGROUND

Acute psychological stress can produce significant hemoconcentration as well as prothrombotic changes in blood, both of which may have potentially harmful effects on the cardiovascular system. It is unclear whether these effects are independent or have influence on each other.

PURPOSE

This review discusses research investigating the effects of acute psychological stress on hemoconcentration and hemostasis and explores future directions for psychohematology research. Physiology, associations with cardiovascular disease, and relationships between acute psychological stress are discussed independently for hemoconcentration and hemostasis, followed by an examination of the effects of stress-hemoconcentration on hemostasis.

CONCLUSIONS

Traditional methods of adjusting for stress-hemoconcentration effects (e.g., calculated plasma volume or hematocrit level corrections) may not be appropriate when examining stress-induced changes in hemostasis. The effects of acute stress on hemostasis should be examined in conjunction with hemoconcentration.

Physical health problems after single trauma exposure: when stress takes root in the body

Research has established that chronic stress, including traumatic events, leads to adverse health outcomes. The literature has primarily used two approaches: examining the effect of acute stress in a laboratory setting and examining the link between chronic stress and negative health outcomes. However, the potential health impact of a single or acute traumatic event is less clear. The goal of this literature review is to extend the literature linking both chronic trauma exposure and posttraumatic stress disorder to adverse health outcomes by examining current literature suggesting that a single trauma may also have negative consequences for physical health. The authors review studies on health, including cardiovascular, immune, gastrointestinal, neurohormonal, and musculoskeletal outcomes; describe potential pathways through which single, acute trauma exposure could adversely affect health; and consider research and clinical implications.

[Psychiatric and behavioral aspects of cardiovascular disease: epidemiology, mechanisms, and treatment]

Psychosocial and behavioral factors, including mood (depression, anxiety, anger, and stress), personality (Type A, Type D, and hostility), and social support, are associated with both the development and progression of cardiovascular disease. "Negative" emotions have been associated with increased rates of cardiovascular death and recurrent cardiac events, although the mechanisms responsible for this association remain unclear. A number of pathophysiological mechanisms have been proposed to explain these relationships, including hypothalamic-pituitary-adrenal axis dysregulation, platelet activation, and inflammation. Behavioral factors also have been implicated, such as nonadherence to prescribed medical therapies and physical inactivity. Several randomized trials of patients with cardiovascular disease have examined the impact of pharmacologic and behavioral treatments on hard cardiovascular disease events as well as on cardiovascular disease biomarkers of risk. Although psychological treatments generally have been shown to improve quality of life and psychological functioning among cardiac patients, the benefit of psychological interventions with respect to improving clinical outcomes has not been conclusively demonstrated.

[Psychiatric and behavioral aspects of cardiovascular disease: epidemiology, mechanisms, and treatment]

Psychosocial and behavioral factors, including mood (depression, anxiety, anger, and stress), personality (Type A, Type D, and hostility), and social support, are associated with both the development and progression of cardiovascular disease. "Negative" emotions have been associated with increased rates of cardiovascular death and recurrent cardiac events, although the mechanisms responsible for this association remain unclear. A number of pathophysiological mechanisms have been proposed to explain these relationships, including hypothalamic-pituitary-adrenal axis dysregulation, platelet activation, and inflammation. Behavioral factors also have been implicated, such as nonadherence to prescribed medical therapies and physical inactivity. Several randomized trials of patients with cardiovascular disease have examined the impact of pharmacologic and behavioral treatments on hard cardiovascular disease events as well as on cardiovascular disease biomarkers of risk. Although psychological treatments generally have been shown to improve quality of life and psychological functioning among cardiac patients, the benefit of psychological interventions with respect to improving clinical outcomes has not been conclusively demonstrated.

Research on the correlation between platelet gelsolin and blood-stasis syndrome of coronary heart disease

OBJECTIVE

To study the distribution of gelsolin in human platelet and plasma, and the association with blood-stasis syndrome (BSS) of coronary heart disease (CHD).

METHODS

Sixty patients with CHD (30 in BSS group and 30 in non-BSS group) and 30 healthy subjects (control group) were included in this study. The classification of the syndrome was based on clinical symptoms and signs. Gelsolin concentration in platelet rich plasma (PRP), platelet poor plasma (PPP), filamentous actin (F-actin) and group-specific component globulin (Gc-globulin) of PPP were determined by enzyme-linked immunosorbent assay (ELISA). The fluorescence intensity of CD62p and cytoplasmic calcium ([Ca(2+)](i)) in human platelets of patients and healthy persons was measured with flow cytometry.

RESULTS

Compared with the control group, gelsolin in PRP of the BSS group increased significantly (P<0.01), while that in PPP of the BSS and non-BSS groups decreased markedly (P<0.05), the CD62p, [Ca(2+)](i) of platelet, F-actin, and Gc-globulin of the BSS and non-BSS groups increased significantly (P<0.01). Compared with the non-BSS group, the gelsolin concentration in PRP of BSS group increased significantly (P<0.01), the [Ca(2+)](i) of platelet of the BSS group increased markedly (P<0.01), while the F-actin and Gc-globulin of the BSS group had no statistical defference (P>0.05).

CONCLUSIONS

Gelsolin concentration in PRP was increased and accompanied by the elevated [Ca(2+)](i) of platelet in CHD with BSS, while gelsolin in PPP were lowered markedly. We speculate that plasma gelsolin may clear F-actin from circulation, thus resulting in depletion of plasma gelsolin significantly. This, in addition to the increased calcium influx of platelets, may lead to the gelsolin abnormal expression on platelets during the process of BSS in CHD. Therefore, platelet gelsolin may serve as a new potential biomarker and a therapeutic target of BSS in CHD.

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.

Stress-induced salivary cortisol secretion during hypobaric hypoxia challenge and in vivo urinary thromboxane production in healthy male subjects

Few studies have assessed the effects of stress on in vivo platelet activation. In the present study, hypobaric hypoxia induced by rapid decompression during high-altitude simulated flight in a hypobaric chamber was used to evaluate the effects of environmental stress on salivary cortisol and urinary thromboxane metabolite (TXM) excretion, a noninvasive marker of in vivo platelet function. Twenty-one male aviators (mean ± SD age = 36 ± 7 years) experiencing hypoxia by removing their oxygen mask for 4-5 min during a simulated flight to 25,000 ft (7,620 m; pO(2) = 59.17 mmHg) and a matched control group of thirteen flying instructors wearing oxygen masks during the challenge, were studied. Hypobaric hypoxia induced a transient significant increase (P < 0.001) in the aviators' salivary cortisol concentration; the overall pattern of diurnal cortisol fluctuation was maintained in both groups. Urinary TXM showed a significant ∼30% reduction (P < 0.01) after the chamber session in aviators exposed to hypobaric hypoxia, but not in controls. A significant inverse correlation was found between salivary cortisol and urinary TXM in aviators (r = - 0.64, P = 0.0015). Salivary cortisol was a significant predictor (P < 0.001) for urinary TXM concentrations in aviators. In conclusion, here we observed that an acute stress-induced salivary cortisol increase was associated with reduced urinary thromboxane biosynthesis, providing the first indirect evidence for an inhibitory effect of acute stress on in vivo platelet function.

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.

Is having polycystic ovary syndrome a predictor of poor psychological function including anxiety and depression?

BACKGROUND

The impact of metabolic and reproductive features of polycystic ovary syndrome (PCOS) compromises psychological functioning. We investigated factors associated with negative psychological functioning to determine whether they were predictive of anxiety and depression in PCOS.

METHODS

A cross-sectional study was performed by questionnaire in 177 women with PCOS (mean ± SD age 32.8 ± 7.8 years) and 109 healthy controls (mean age 41.9 ± 15.4 years). Main outcome measures were anxiety and depression, measured using the Hospital Anxiety Depression Scale (HADS) and Multidimensional Body-Self Relations Questionnaire (MBSRQ), respectively.

RESULTS

Women with PCOS, compared with control women, had a higher mean anxiety HADS score (9.5 ± 3.9 versus 6.5 ± 3.6; P < 0.001), a higher mean depression score (5.7 ± 3.7 versus 3.3 ± 3.1; P < 0.001) and more negative body image in 7 out of 10 subscales of the MBSRQ. Multivariate regression analysis in PCOS showed that anxiety was predicted by self-worth (P < 0.0001), health evaluation (P = 0.005), time taken to diagnose PCOS (P = 0.003) and age (P = 0.02), while in control women, anxiety was predicted by self-worth (P = 0.009), health evaluation (P = 0.001) and rural living (P = 0.03). Depression in PCOS was predicted by self-worth (P = 0.0004), quality of life (QOL) (P = 0.004), fitness orientation (P = 0.002), appearance evaluation (P = 0.001) and time to diagnosis (P = 0.03) and in women without PCOS, by self-worth (P < 0.0001), QOL (P < 0.0001), illness orientation (P = 0.001) and appearance orientation (P = 0.02).

CONCLUSIONS

Women with PCOS have increased anxiety, depression and negative body image compared with women without PCOS. In women with or without PCOS, body image and self-worth are predictors of both anxiety and depression, while QOL also predicts only depression. Time taken to diagnose PCOS is associated with poor psychological functioning.

Contribution of diet and major depression to incidence of acute myocardial infarction (AMI)

BACKGROUND

Despite significant improvements in the treatment of coronary heart disease (CHD), it is still a major cause of mortality and morbidity among the Iranian population. Epidemiological studies have documented that risk factors including smoking and the biochemical profile are responsible for the development of acute myocardial infarction (AMI). Psychological factors have been discussed as potential risk factors for coronary heart disease. Among emotional factors, depression correlates with coronary heart disease, particularly myocardial infarction.

METHODS

This case-control study was conducted on 120 cases (69 males and 51 females) of acute myocardial infarction (AMI) and 120 controls, with a mean age of 62.48 ± 15.39 years. Cases and controls were matched by age, residence and sex.

RESULTS

The results revealed that severe depression was independently associated with the risk of AMI (P = 0.025, OR = 2.6, 95% CI 1.1-5.8). The analysis of variables indicated that risk factors for developing depression were unmarried, low levels of polyunsaturated fatty acids (PUFAs), total dietary fiber (TDF) and carbohydrates. The levels of these dietary factors were lowest in severely depressed patients compared to those categorised as moderate or mild cases. Furthermore, severely depressed subjects were associated with higher levels of total cholesterol, high systolic blood pressure (SBP) and WHR. Age, income, a family history of coronary heart disease, education level, sex, employment and smoking were not associated with severe depression.

CONCLUSION

The present study demonstrated that severe depression symptoms are independent risk factors for AMI. Furthermore, severe depression was associated with an unhealthy diet and AMI risk factors.

Genetic variability and the risk of myocardial infarction in Poles under 45 years of age

INTRODUCTION

Myocardial infarction is caused by the obstruction of an artery in places of atherosclerosis plaque rupture. Endothelial cells during their activation express chemoattractant and adhesion molecules whereas infiltrating inflammatory cells produce enzymes, predisposing a lesion to rupture.

MATERIAL AND METHODS

We investigated the correlation between polymorphisms in the human genes E-selectin (Ser128Arg), ICAM1 (K469E), OLR1 (K167N), MMP1 (1G/2G) and MMP3 (-1612 5A/6A) and the risk of MI in young Poles under 45 years. There was no significant difference in the frequency of single nucleotide polymorphism (SNP) of the studied genes E-selectin (Ser128Arg), ICAM1 (K469E), OLR1 (K167N) and MMP3 (-1612 5A/6A) between patients with MI and controls.

RESULTS

The analysis of the association of the 1G2G polymorphism with the risk of myocardial infarction indicated an odds ratio (OR) of 5.68 (95% confidence interval [95% CI] 2.60 to 12.36). Other factors associated with myocardial infarction were: smoking (OR 4.12; 95% CI 1.63-10.44), male sex (OR 16.02; 95% CI 5.90-43.46), hypercholesterolaemia (OR 2.74; 95% CI 1.29-5.83) and arterial hypertension (OR 4.56; 95% CI 1.66-14.47).

CONCLUSIONS

We found that only MMP1 1G/2G polymorphism is associated with myocardial infarction in the Polish population of individuals younger than 45 years. Clinical factors seemed to play a greater role in the analysed group.

Modified serum profiles of inflammatory and vasoconstrictive factors in patients with emotional stress-induced acute coronary syndrome during World Cup Soccer 2006

OBJECTIVES

We sought to assess whether emotional stress-induced acute coronary syndrome (ACS) is mediated by increased inflammatory and vasoconstrictive mediators.

BACKGROUND

The World Cup soccer 2006 has been shown to provoke levels of stress sufficient to increase the incidence of ACS. However, the mechanisms by which stress translates into vascular injury up to plaque rupture still remain elusive.

METHODS

Serum levels of soluble CD40L (sCD40L), soluble vascular cell adhesion molecule (sVCAM)-1, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hsCRP), regulated on activation, normal T-cell expressed and secreted (RANTES), and endothelin (ET)-1 were determined in patients who experienced an ACS during World Cup matches, in ACS reference patients (not associated with emotional stress), and in healthy volunteers. Correlations and receiver-operating characteristic curves were calculated to develop multivariable analysis and to investigate the diagnostic value of each parameter.

RESULTS

The sCD40L, sVCAM-1, MCP-1, TNF-alpha, and ET-1 were significantly higher in study patients compared with the reference group. The hsCRP was similar in both groups, whereas RANTES was decreased in study patients. A positive correlation was found between ET-1 and soccer-induced enhanced levels of sCD40L, sVCAM-1, MCP-1, and TNF-alpha. Receiver-operating characteristic analysis displayed high performance of both MCP-1 and ET-1 as a measure to discriminate between stress-induced ACS and ACS controls.

CONCLUSIONS

Stress-induced ACS is associated with a profound increase of inflammatory and vasoconstrictive mediators. The evaluation of a targeted drug delivery, such as anti-inflammatory agents, ET-1 receptor antagonists, or inhibition of endothelin-converting enzyme is warranted to reduce stress-mediated cardiovascular morbidity.

The first- and second-generation antipsychotic drugs affect ADP-induced platelet aggregation

OBJECTIVE

Blood platelets play an important role in haemostasis and their hyperaggregability may lead to thrombosis and cardiovascular diseases. Increased incidence of mortality, caused by cardiovascular disease, and the increased risk of thrombotic complication in schizophrenic patients treated with antipsychotics have been reported. The effects of antipsychotic drugs on blood platelet function are not fully explained, therefore the purpose of the present study was to examine and compare the effects of the second-generation antipsychotic drugs used in schizophrenia (clozapine, risperidone and olanzapine), with the effects of the first generation antipsychotic, haloperidol, on the platelet aggregation induced by ADP in vitro.

METHODS

Blood obtained from healthy volunteers (n=25) collected into sodium citrate was centrifuged (250xg, 10 min) at room temperature to obtain platelet-rich plasma. Aggregation of blood platelets (10 microM ADP) was recorded (Chrono-log aggregometer) in platelet-rich plasma preincubated with antipsychotic drugs (final concentration: clozapine 420 ng/ml, risperidone 65 ng/ml, olanzapine 40 ng/ml, haloperidol 20 ng/ml) for 30 min.

RESULTS

Our results showed that all tested drugs inhibit platelet aggregation induced by ADP in vitro. Among studied antipsychotic drugs clozapine and olanzapine significantly reduced platelet aggregability in vitro. In comparison with control platelets (without the drug), clozapine inhibited ADP-induced platelet aggregation by 21% (P=3.7x10(-6)) and olanzapine by 18% (P=2.8x10(-4)), respectively.

CONCLUSION

The obtained results indicate that antipsychotic drugs, especially clozapine and olanzapine, contrary to haloperidol, reduced response of blood platelets to ADP measured as platelet aggregation. This suggests that therapy with such antipsychotics, particularly with second-generation antipsychotics, may partly reduce prothrombotic events associated with the increased platelet activation observed in schizophrenic patients. The mechanism of antiaggregatory influence of antipsychotics requires further studies.

Longitudinal platelet reactivity to acute psychological stress among older men and women

Platelet reactivity to acute stress is associated with increased cardiovascular disease risk; however, little research exists to provide systematic methodological foundations needed to generate strong longitudinal research designs. Study objectives were: 1) to evaluate whether markers of platelet function increase in response to an acute psychological stress test among older adults, 2) to establish whether reactivity remains robust upon repeated administration (i.e. three occasions approximately 1 year apart), and 3) to evaluate whether two different acute speech stress tasks elicit similar platelet responses. The 149 subjects (mean age 71 years) gave a brief impromptu speech on one of two randomly assigned topics involving interpersonal conflict. Blood samples drawn at baseline and post-speech were assayed using flow cytometry for platelet responses on three outcomes (% aggregates, % P-selectin expression, and % fibrinogen receptor expression). Three-level hierarchical linear modeling analyses revealed significant stress-induced increases in platelet activation on all outcomes (p < 0.001). No significant habituation on any measure was found. Additional reactivity differences were associated with male gender, history of myocardial infarction, and use of aspirin, statins, and antidepressants. The results demonstrate that laboratory acute stress tests continued to produce robust platelet reactivity on three activation markers among older adults over 3 years.

Mental-stress-induced platelet activation among patients with coronary artery disease

OBJECTIVE

To study patients with coronary artery disease (CAD) scheduled for coronary angioplasty and to examine platelet activation in response to mental stress as a potential mechanism involved in the association between psychosocial factors and cardiac outcomes. Psychosocial factors have been identified as risk factors for CAD and adverse cardiac outcomes, although the underlying mechanisms are poorly understood.

METHODS

Markers of platelet activation and platelet reactivity in response to experimentally induced mental stress (mental arithmetic and anger recall) were examined, using flow cytometry analysis and beta-thromboglobulin (BTG) assays among 249 CAD patients (age = 60.3 +/- 9.0 years, 15% women) who were scheduled to undergo elective percutaneous coronary intervention.

RESULTS

Mental stress-induced increases in platelet activation (CD41 (GP IIb/IIIa), p = .002; percent of mononuclear cells positive for CD41, p = .01; CD62P (P-selectin) expression, p = .005; and percent platelets positive for CD62P, p < .001). The degree of platelet reactivity was not related to demographic, clinical, or psychological variables, or cardiovascular hemodynamic changes.

CONCLUSIONS

Experimentally induced mental stress induced platelet activation in patients with CAD. This mechanism may partially explain the link between psychosocial variables and the development of adverse cardiac outcomes in patients with CAD.

Association between perceived stress and plasma B-type natriuretic peptide concentrations

BACKGROUND

Many patients with heart disease continue to have cardiac events despite receiving optimal treatments for traditional risk factors. Consequently, non-traditional risk factors for heart disease, such as perceived stress, have attracted attention. Associations between perceived stress and plasma B-type natriuretic peptide (BNP) were explored, while controlling for traditional heart disease risk factors.

METHODS AND RESULTS

This cross-sectional study examined 360 male and 446 female (age, >40 years) residents of a rural Japanese community who received annual health checkups in 2006. A lifestyle questionnaire was used to obtain information regarding perceived stress and medical history, and routine anthropometric and blood pressure measurements and a laboratory assessment of cardiovascular risk factors, including plasma BNP concentrations and an electrocardiogram, were done. After adjusting for traditional heart disease risk factors, multiple regression analysis showed that perceived stress was associated with BNP concentrations, particularly in women (F=6.12, P=0.026). In addition, multiple tests using Bonferroni's procedure showed that BNP concentrations decreased with perceived stress level in men and women. Similar trends were observed in the sub-analyses of subjects with and without known heart disease.

CONCLUSIONS

Perceived stress in our study was negatively associated with plasma BNP concentrations, independently of traditional heart disease risk factors.

Atherosclerotic plaque disruption induced by stress and lipopolysaccharide in apolipoprotein E knockout mice

To establish an animal model with disruptions of atherosclerotic plaques, 96 male apolipoprotein E knockout (apoE(-/-)) mice were randomly divided into stress, lipopolysaccharide (LPS), stress+LPS, and control groups (n = 24 each). All mice were fed a high-fat diet throughout the experiment, and carotid atherosclerotic lesions were induced by placement of a constrictive perivascular collar. Four weeks after surgery, mice in the LPS and stress+LPS groups were intraperitoneally injected with LPS (1 mg/kg twice per week for 8 wk). Eight weeks after surgery, mice in the stress and stress+LPS groups were treated with intermittent physical stress (electric foot shock and noise stimulation) for 4 wk. Morphological analysis revealed a plaque disruption rate of 16.7% in control, 34.8% in LPS, 54.2% in stress, and 60.9% in stress+LPS groups. The disruption rates in stress and stress+LPS groups were both significantly higher than those of controls (P = 0.007 and P = 0.002, respectively). Luminal thrombosis secondary to plaque disruption was observed only in the stress+LPS group. Both stress and LPS stimulation significantly decreased fibrous cap thickness and increased macrophage and lipid contents in plaques. Moreover, the combination of stress and LPS stimulation further lowered cap thickness and enhanced accumulation of macrophages and expression of inflammatory cytokines and matrix metalloproteinases. Stress activated the sympathetic nervous system, as manifested by increased blood pressure and flow velocity. Plasma fibrinogen levels were remarkably elevated in the stress and stress+LPS groups. In conclusion, stress- and LPS-costimulated apoE(-/-) mice provide a useful model for studies of plaque vulnerability and interventions.

Stress, depression, and coronary artery disease: modeling comorbidity in female primates

Depression and coronary heart disease (CHD) are leading contributors to disease burden in women. CHD and depression are comorbid; whether they have common etiology or depression causes CHD is unclear. The underlying pathology of CHD, coronary artery atherosclerosis (CAA), is present decades before CHD, and the temporal relationship between depression and CAA is unclear. The evidence of involvement of depression in early CAA in cynomolgus monkeys, an established model of CAA and depression, is summarized. Like people, monkeys may respond to the stress of low social status with depressive behavior accompanied by perturbations in hypothalamic-pituitary-adrenal (HPA), autonomic nervous system, lipid metabolism, ovarian, and neural serotonergic system function, all of which are associated with exacerbated CAA. The primate data are consistent with the hypothesis that depression may cause CAA, and also with the hypothesis that CAA and depression may be the result of social stress. More study is needed to discriminate between these two possibilities. The primate data paint a compelling picture of depression as a whole-body disease.

Chronic stress and individual vulnerability

Over the last decades the burden of disease in Western countries has shifted from comparably easily treated infectious diseases to more complex diseases, such as the metabolic syndrome, cardiovascular disease, and psychiatric disorders. A common characteristic of these illnesses is the interplay of multiple genetic and nongenetic factors, which eventually results in the manifestation of disease symptoms. Large-scale epidemiological studies in humans have resulted in the identification of various environmental and genetic risk factors, which contribute to the onset, duration, and severity of disease. While tremendous progress has been made, it is still impossible to predict which combination of risk factors will result in the manifestation of a specific illness. This lack of knowledge is also frequently reflected in inadequate treatment strategies, which mainly focus on symptom reversal rather than targeting the cause of the diseases. One of the most prominent environmental risk factors described for numerous diseases is chronic exposure to stressful situations. In this paper we address clinical and preclinical evidence of chronic stress as a risk factor for disease and introduce a novel, high-throughput mouse model for chronic social stress. We can show that this model has a high degree of construct, face, and predictive validity in terms of physiological, behavioral, and gene expression changes. We further illustrate how novel animal models of chronic social stress can help to unravel the complex interaction of individual genetic vulnerability and environmental risk factors.

Effect of having a sense of purpose in life on the risk of death from cardiovascular diseases

Background

Many studies have focused on disease causality, but few of them deal with health-promoting factors. Thus, we examined the effect of having a sense of purpose in life (ikigai) on mortality from cardiovascular disease (CVD).

Methods

In 1988, we conducted a prospective cohort study of 2,959 Japanese subjects, ranging in age from 40 to 74 years, and followed them till the end of 2003. The level of their sense of purpose in life was evaluated by a self-administered questionnaire. After excluding those with a history of heart disease, stroke, or malignant tumor, 1,618 subjects (832 men and 786 women) who had completed the questionnaire were used in the analyses with Cox’s proportional hazards model.

Results

During the average 13.3 years of follow up, 249 deaths (172 men and 77 women) occurred as a result of all causes: 32 from heart disease, 31 from stroke, 63 from CVD, and 104 from malignant tumors. The adjusted hazard ratios for death in men with a strong sense of purpose in life, as compared with those with a low sense of purpose, were 0.28 (95% confidence interval: 0.10-0.84) for stroke, 0.56 (0.28-1.10) for CVD, and 0.62 (0.45-0.86) as a result of all causes. In women, no significant relationship was found between having a sense of purpose in life and mortality; this was possibly because the smaller number of deaths reduced the statistical significance.

Conclusion

We found that in men, having a sense of purpose in life affected the risk of death as a result of all causes, stroke, and CVD.

The impact of psychoticism on perceived hassles, depression, hostility, and hopelessness in non-psychiatric African Americans

Psychotic symptoms are distributed along a continuum that extends from normality to diagnosable psychotic disorders and the presence of psychoticism among individuals in the general population may lead to morbidity and social impairment. This study examined a model in which psychoticism leads to several important psychological consequences. The analysis included 134 African Americans with no psychiatric history who were being seen in medical walk-in clinics for non-emergency medical problems. Psychoticism, perceived hassles, depression, hostility, and hopelessness were measured. The Linear Structural Relations Program (LISREL) was used to test the fit of the data to the proposed model, a trimmed hierarchical version, and two alternative models. The data supported a model in which psychoticism has substantial effects on several important characteristics: perceived daily hassles, depression, and hostility. Depression mediated the association between psychoticism and hopelessness. Goodness-of-fit indices for a final trimmed model that eliminated one path from the initial postulated model revealed good fit to the data, and the two alternative models were found not to fit the data. Like psychosis itself, psychoticism appears to cause meaningful dysfunction even among non-psychiatric individuals from the general population. Additional research is needed to further characterize the detrimental effects of psychoticism or self-reported psychotic symptoms in the general, non-psychiatric population.

Emotional triggering of cardiac events

Psychological factors may contribute not only to the evolution of coronary atherosclerosis and long-term risk of coronary heart disease, but also to the triggering of acute cardiac events in patients with advanced atherosclerosis. Evidence for emotional triggering of cardiac events derives both from population-based studies of hospital admissions and sudden deaths following major traumas such as earthquakes and terrorist incidents, and from individually based interview studies with survivors of acute coronary syndromes (ACS). The latter indicate that acute anger, stress and depression or sadness may trigger ACS within a few hours in vulnerable individuals. The psychobiological processes underlying emotional triggering may include stress-induced haemodynamic responses, autonomic dysfunction and parasympathetic withdrawal, neuroendocrine activation, inflammatory responses involving cytokines and chemokines, and prothrombotic responses, notably platelet activation. These factors in turn promote coronary plaque disruption, myocardial ischaemia, cardiac dysrhythmia and thrombus formation. The implications of these findings for patient care and ACS prevention are outlined.

Effects of depressive and anxious symptoms on norepinephrine and platelet P-selectin responses to acute psychological stress among elderly caregivers

BACKGROUND

Caring for a spouse with Alzheimer's disease is associated with increased psychological distress, impaired immunity, and heightened cardiovascular risk. Hyperreactivity of sympathetic and platelet activation responses to acute psychological stress, or the failure to recover quickly from stressful events, may constitute an important pathway linking stress and negative affect with cardiovascular disease (CVD).

OBJECTIVES

(1) To evaluate associations between negative affect (i.e., depressive and anxious symptoms) with increased norepinephrine and P-selectin responses to an acute psychological stress task. (2) To establish whether these associations are augmented among elderly spousal caregivers (CG) compared to non-caregivers (NC).

METHODS

Depressive (DEP) and anxious (ANX) symptoms from the Brief Symptom Inventory were assessed among 39 CG and 31 NC. Plasma norepinephrine levels (NE) and percent platelet P-selectin (PSEL) expression were assayed at three time-points: rest, immediately following a laboratory speech test (reactivity), and after 14 min of recovery.

RESULTS

Among CG, but not NC, increased symptoms of depression and anxiety were associated with delayed NE recovery (DEP: beta=.460, p=.008; ANX: beta=.361, p=.034), increased PSEL reactivity (DEP: beta=.703, p<.001; ANX: beta=.526, p=.002), and delayed PSEL recovery (DEP: beta=.372, p=.039; ANX: beta=.295, p=.092), while controlling for age, gender, aspirin use, antidepressant use, and preexisting CVD. Bivariate correlations showed delayed NE recovery was also associated with increased PSEL reactivity (r=.416) and delayed PSEL recovery (r=.372; all ps<.05) among CG but not NC.

DISCUSSION

Among chronically stressed caregivers, increased levels of depressive and anxious symptoms are associated with prolonged sympathetic activation and pronounced platelet activation. These changes may represent one pathway linking caregiving stress to cardiovascular risk.

Behavioral Medicine Review: Psychological Risks for Metabolic Syndrome

Despite their ubiquity in primary care, psychological disorders often are overlooked as cues to heightened risk for metabolic syndrome (MetS), potentially leading to the suboptimal management of patients with these comorbid conditions. Accordingly, this review discusses psychological dysfunction as an under-appreciated MetS hazard and the strategic implications for cardiometabolic risk reduction in primary care.

Effects of aspirin and propranolol on the acute psychological stress response in factor VIII coagulant activity: a randomized, double-blind, placebo-controlled experimental study

Activity of clotting factor VIII has been shown to acutely increase with sympathetic nervous system stimulation. We investigated whether aspirin and propranolol affect the responsiveness of plasma clotting factor VIII activity levels to acute psychosocial stress. We randomized 54 healthy subjects double-blind to 5-day treatment with a single daily oral dosage of either 100 mg aspirin plus 80 mg propranolol combined, 100 mg of aspirin, 80 mg of propranolol, or placebo medication. Thereafter, subjects underwent a 13-min standardized psychosocial stressor. Plasma levels of clotting factor VIII activity were determined immediately before, immediately after, 45 min and 105 min after stress. Controlling for demographic, metabolic, and life style factors repeated measures analysis of covariance showed that the change in clotting factor VIII activity from prestress to 105 min poststress differed between medication groups (P = 0.023; partial eta = 0.132). The clotting factor VIII activity level decreased from prestress to immediately poststress in the aspirin/propranolol group relative to the placebo group (P = 0.048) and the aspirin group (P < 0.06). Between 45 min and 105 min poststress, clotting factor VIII levels increased in the aspirin/propranolol group relative to the placebo group (P = 0.007) and the aspirin group (P = 0.039). The stress response in clotting factor VIII activity levels was not significantly different between the aspirin/propranolol group and the propranolol group. Propranolol in combination with aspirin diminished the acute response in clotting factor VIII activity to psychosocial stress compared with placebo medication and aspirin alone. The effect of single aspirin on the acute clotting factor VIII stress response was indistinguishable from a placebo effect.

Administration of minor polar compound-enriched extra virgin olive oil decreases platelet aggregation and the plasma concentration of reduced homocysteine in rats

We investigated the effect of extra virgin olive oil (EVOO) on platelet aggregation and plasma concentrations of homocysteine (Hcy) redox forms in rats in relation to the minor polar compound (MPC) concentration of EVOO. We used 3 olive oil samples with similar fatty acid but different MPC concentrations: refined olive oil (RF) with traces of MPC (control oil), native EVOO with low MPC concentration (LC), and EVOO with high MPC concentration (HC) enriching LC with its own MPC. Oil samples were administered to rats by gavage (1.25 mL/kg body weight) using 2 experimental designs: acute (24-h food deprivation and killed 1 h after EVOO administration) and subacute (12-d treatment, a daily dose of oil for 12 d, and killed after 24 h of food deprivation). Platelet aggregation was induced by ADP (ex vivo tests) and a reduction in platelet reactivity occurred in cells from rats given LC in the subacute study and in cells from rats administered HC in both studies as indicated by an increase in the agonist half maximal effective concentration. HC inhibited platelet aggregation induced by low ADP doses (reversible aggregation) in cells of rats in both the acute and subacute studies, whereas LC had this effect only in the subacute experiment. Moreover, in rats administered HC in both experiments, the plasma concentration of free reduced Hcy (rHcy) was lower and Hcy bound to protein by disulfide bonds (bHcy) was greater than in RF-treated rats. bHcy was also greater in rats given LC than in RF-treated rats in the subacute experiment. Plasma free-oxidized Hcy was greater in rats given LC and HC than in those administered RF only in the subacute experiment. In conclusion, these results show that MPC in EVOO inhibit platelet aggregation and reduce the plasma rHcy concentration, effects that may be associated with cardiovascular protection.

Psychological distress, physical illness and risk of myocardial infarction in the Caerphilly study

BACKGROUND

Studies have found associations between psychological distress (PD) and increased risk of myocardial infarction (MI). However, it is not clear whether the relationship reflects the subtle influence of pre-existing illness on both PD and MI. This study examines the association between PD and MI in a prospective epidemiological study of 1864 middle-aged men to examine if the association is explained by existing illness.

METHOD

This study was a prospective cohort study modelling the association between PD, measured using the 30-item General Health Questionnaire (GHQ) and non-fatal myocardial infarction (NFMI) and fatal/non-fatal myocardial infarction (FNFMI). The relationship was modelled in a series of logistic regression models adjusted for age, then cigarette smoking, then social position, and finally for all sociodemographic characteristics, coronary heart disease (CHD) risk factors, and baseline CHD.

RESULTS

PD was associated with a 70% and 68% increased risk of NFMI and FNFMI in fully adjusted analysis. However, PD was not associated with an increased risk of NFMI and FNFMI in analyses excluding those with baseline CHD. Further, being psychologically distressed and physically ill was associated with a greater than twofold risk of NFMI and FNFMI, 2.37 (95% CI 1.33-4.20) and 2.33 (95% CI 1.32-4.12) respectively.

CONCLUSIONS

This study suggests that PD is a moderator of the increased risk of MI associated with existing physical illness. PD in men who are physically ill is a marker of an underlying chronic physical illness. The prospective association of PD with MI is not independent of baseline physical illness.

Baseline level of platelet-leukocyte aggregates, platelet CD63 expression, and soluble P-selectin concentration in patients with posttraumatic stress disorder: a pilot study

Platelets may have an important role in the development of cardiovascular disease (CVD) as a result of chronic stress. We conducted a pilot study to evaluate the effect of posttraumatic stress disorder (PTSD) on baseline platelet activation. Platelet-leukocyte aggregates (PLA) and CD63 expression were measured by flow cytometry, and soluble (s)P-selectin concentration was determined in sera of 20 Croatian male combat veterans with PTSD and 20 healthy civilians. Groups were matched in sex, age, body mass index (BMI) and traditional CVD risk factors. Our data showed no differences in measured parameters. Other platelet activation markers should be determined and a larger sample size used in future studies.

A systematic review of the effects of acute psychological stress and physical activity on haemorheology, coagulation, fibrinolysis and platelet reactivity: Implications for the pathogenesis of acute coronary syndromes

Physical activity and psychological stress are two potential triggers for the onset of acute coronary syndromes (ACS). To examine the mechanisms underlying this association, we systematically reviewed the literature to determine the effects of acute psychological stress and physical activity on haemorheology and haemostasis. Studies examining the haemorheological and haemostatic response to an acute bout of physical activity (i.e. <60 min) or laboratory psychological stress task were eligible for inclusion. The experimental evidence, although compromised by various methodological weaknesses, suggests that low and moderate intensity physical activity may be cardio-protective through beneficial effects on fibrinolytic system. High levels of physical activity, and psychological to a lesser extent, have been consistently associated with robust changes in haemorheology and haemostasis. Such findings imply that such activities may have the potential to trigger the onset of ACS, although in reality this may be limited sedentary individual and/or those with pre-existing vascular disease. In addition, the data also suggest that individuals may be at a greatest risk of stress-induced thrombogenesis in the period immediately following physical activity or psychological stress, rather than during the activity per se. In conclusion, psychological stress and physical activity may act as potential triggers for the onset of ACS via effects on haemostasis and haemorheology.

The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial

RATIONALE

Tea has anecdotally been associated with stress relief, but this has seldom been tested scientifically.

OBJECTIVES

To investigate the effects of 6 weeks of black tea consumption, compared with matched placebo, on subjective, cardiovascular, cortisol and platelet responses to acute stress, in a parallel group double-blind randomised design.

MATERIALS AND METHODS

Seventy-five healthy nonsmoking men were withdrawn from tea, coffee and caffeinated beverages for a 4-week wash-out phase during which they drank four cups per day of a caffeinated placebo. A pretreatment laboratory test session was carried out, followed by either placebo (n = 38) or active tea treatment (n = 37) for 6 weeks, then, a final test session. Cardiovascular measures were obtained before, during and after two challenging behavioural tasks, while cortisol, platelet and subjective measures were assessed before and after tasks.

RESULTS

The tasks induced substantial increases in blood pressure, heart rate and subjective stress ratings, but responses did not differ between tea and placebo treatments. Platelet activation (assessed using flow cytometry) was lower following tea than placebo treatment in both baseline and post-stress samples (P < 0.005). The active tea group also showed lower post-task cortisol levels compared with placebo (P = 0.032), and a relative increase in subjective relaxation during the post-task recovery period (P = 0.036).

CONCLUSIONS

Compared with placebo, 6 weeks of tea consumption leads to lower post-stress cortisol and greater subjective relaxation, together with reduced platelet activation. Black tea may have health benefits in part by aiding stress recovery.

Mental stress and coronary artery disease: a multidisciplinary guide

Research suggests that acute and chronic stress are risk factors for the development and progression of coronary artery disease. Much of this work is multidisciplinary, using unfamiliar concepts deriving from disciplines other than cardiology and medicine. This article addresses and clarifies, for the cardiologist, some of the key concepts and issues in this area and provides an overview of evidence linking acute and chronic stress to cardiac pathology. Areas addressed include definitions and measurement of mental stress, methodological issues in stress research, and distinctions between stress and variables such as personality, emotion, and depression. Mental stress is a multifactorial process involving the environment, individual experiences and coping, and a set of neuroendocrine, autonomic, cardiovascular, and other systemic physiologic responses. There are difficulties identifying a single consensus physiologic stress measure because of individual differences in perceptions and physiologic response patterns. Nonetheless, important associations exist between mental stress and clinically relevant cardiovascular end points. As multidisciplinary research in this area continues, one major goal is the better integration of psychosocial knowledge and measures with cardiology research and practice.

Mood disorders: cardiovascular and diabetes comorbidity

PURPOSE OF REVIEW

Depression is often associated with medical comorbidity. New research quantifies patterns of mood disorder in illnesses such as cardiovascular disease and diabetes, evaluates the prognostic significance of mood symptoms, and seeks to identify common mechanisms for both mood and medical disease. This review provides recent findings on comorbidity, summarizes mechanistic hypotheses, and outlines developments in treatment and services.

RECENT FINDINGS

Depression occurs in up to one-quarter of patients with cardiovascular disease and diabetes. Depressed patients with heart disease have poorer medical outcomes including increased risk of reinfarction and all-cause mortality. Patients with diabetes and depression have poorer glycemic control, more diabetes symptoms, and greater all-cause mortality. Depression is associated with both biological (hypothalamic-pituitary-adrenal axis dysregulation) and psychosocial processes (adherence, poorer diet, and exercise) that may mediate adverse medical outcomes. Antidepressant treatments are effective in treating depression in medically ill patients, but their impact on medical outcomes remains to be quantified.

SUMMARY

Depression, cardiovascular disease, and diabetes are among the most common chronic illnesses affecting an aging population. Depression is treatable in patients with medical illnesses, and collaborative care models can yield better detection and depression treatment in primary care settings in which most patients with depression are seen.

Pathophysiological processes underlying emotional triggering of acute cardiac events

Acute negative emotional states may act as triggers of acute coronary syndrome (ACS), but the biological mechanisms involved are not known. Heightened platelet activation and hemodynamic shear stress provoked by acute stress may contribute. Here we investigated whether patients whose ACS had been preceded by acute anger, stress, or depression would show heightened hemodynamic and platelet activation in response to psychophysiological stress testing. We studied 34 male patients an average of 15 months after they had survived a documented ACS. According to an interview conducted within 5 days of hospital admission, 14 men had experienced acute negative emotion in the 2 h before symptom onset, and 20 men had not experienced any negative emotion. Hemodynamic variables and platelet activation were monitored during performance of challenging color-word interference and public speaking tasks and over a 2-h poststress recovery period. The emotion trigger group showed significantly greater increases in monocyte-platelet, leukocyte-platelet, and neutrophil-platelet aggregate responses to stress than the nontrigger group, after adjusting for age, body mass, smoking status, and medication. Monocyte-platelet aggregates remained elevated for 30 min after stress in the emotion trigger group. The emotion trigger group also showed poststress delayed recovery of systolic pressure and cardiac output compared with the nontrigger group. These results suggest that some patients with coronary artery disease may be particularly susceptible to emotional triggering of ACS because of heightened platelet activation in response to psychological stress, coupled with impaired hemodynamic poststress recovery.