Behavioral-neuroendocrine-immunologic interactions in myocardial infarction

Statin Function as an Anti-inflammation Therapy for Depression in Patients With Coronary Artery Disease by Downregulating Interleukin-1β

It is well known that inflammation contributes to the development of coronary artery disease (CAD) and depressive symptoms. Previous studies have shown that long-term application of statin reduces the occurrence of depression in patients with CAD. However, the mechanism remains unclear. We hypothesized that inflammation contributes to depression in patients with CAD and statin function as an anti-inflammation therapy for those depressive patients. Patients with confirmed CAD hospitalized in the Department of Cardiology of Tongji Hospital in Shanghai, China, were enrolled. Depression was identified as none (ND), mild (MiD), moderate (MoD), or severe (SD) on the basis of scores of the patient health questionnaire with 9 items. Inflammatory factors in peripheral blood were measured using a chemiluminescence immunoassay and Bio-plex. Luciferase expression level was detected using the Dual-Luciferase Reporter Assay System for IL-1β or NF-κB expression by transfection in human umbilical vein endothelial cells, and patient serum was added. Data obtained from 217 patients with CAD were analyzed. The IL-1β level of CAD with SD was 14.70, which was significantly higher than that of CAD with ND 7.52, MiD 7.73, or MoD 8.63. Luciferase reporter gene analysis showed that IL-1β or NF-κB expression level was upregulated by the serum of CAD and depression patients. After the addition of atorvastatin, IL-1β or NF-κB luciferase reporter expression level decreased. It suggested that depression in patients with CAD is associated with inflammation. Statin may function as an anti-inflammation therapy for depression in patients with CAD by downregulation of IL-1β.

Consistent associations between measures of psychological stress and CMV antibody levels in a large occupational sample

Cytomegalovirus (CMV) is a herpes virus that has been implicated in biological aging and impaired health. Evidence, largely accrued from small-scale studies involving select populations, suggests that stress may promote non-clinical reactivation of this virus. However, absent is evidence from larger studies, which allow better statistical adjustment for confounding and mediating factors, in more representative samples. The present study involved a large occupational cohort (N=887, mean age=44, 88% male). Questionnaires assessed psychological (i.e., depression, anxiety, vital exhaustion, SF-12 mental health), demographic, socioeconomic (SES), and lifestyle variables. Plasma samples were analyzed for both the presence and level of CMV-specific IgG antibodies (CMV-IgG), used as markers for infection status and viral reactivation, respectively. Also assessed were potential biological mediators of stress-induced reactivation, such as inflammation (C-reactive protein) and HPA function (awakening and diurnal cortisol). Predictors of CMV infection and CMV-IgG among the infected individuals were analyzed using logistic and linear regression analyses, respectively. Confirming prior reports, lower SES (education and job status) was positively associated with infection status. Among those infected (N=329), higher CMV-IgG were associated with increased anxiety (β=.14, p<.05), depression (β=.11, p=.06), vital exhaustion (β=.14, p<.05), and decreased SF-12 mental health (β=-.14, p<.05), adjusting for a range of potential confounders. Exploratory analyses showed that these associations were generally stronger in low SES individuals. We found no evidence that elevated inflammation or HPA-function mediated any of the associations. In the largest study to date, we established associations between CMV-IgG levels and multiple indicators of psychological stress. These results demonstrate the robustness of prior findings, and extend these to a general working population. We propose that stress-induced CMV replication warrants further research as a psychobiological mechanism linking stress, aging and health.

Self-rated stress is noncontributory to coronary artery disease in higher socioeconomic strata

Stress and its attendant psychosocial and lifestyle variables have been associated with coronary artery disease (CAD), yet the contribution of socioeconomic status (SES) has not been addressed. The aim of this study is to determine if stress assessment is associated with CAD independent of SES, and is incremental to the Framingham Score. The study group consisted of 325 executive patients undergoing comprehensive health assessment. Stress was assessed utilizing the validated "Self-Rated Stress" (SRS) instrument. Coronary artery calcification (CAC) served to assess the degree of atherosclerosis, a CAD equivalent and risk assessment tool. The relationship between SRS and CAC was assessed, with adjustment by potential confounders. CAC was modeled by a variety of cut points (>0, ≥5, ≥100, ≥200) for the test of trend across stress levels per Mantel-Haenszel chi-square (1 df) with nonsignificant P values of 0.9960, 0.5242, 0.1692, 0.3233, respectively. A logistic regression model with SRS as a categorically ranked and continuous variable to predict binary outcome of calcification yielded P values of 0.2366 and 0.9644; this relationship, further adjusted by age, fruit and vegetable consumption, exercise, and education, yielded no statistically significant association. No improvement of fit was observed for the established Framingham Score to CAC relation utilizing SRS. The study concluded that SRS did not play a role in early CAD when focusing on a population in higher socioeconomic strata, and SRS did not add predictive value beyond patient age or calculated Framingham risk. Future studies should focus on additional validated instruments of stress to differentiate between subtypes of stress for varying SES strata.

Depression in heart failure: biobehavioral mechanisms

The etiology, predictive value, and biobehavioral aspects of depression in heart failure (HF) are described in this article. Clinically elevated levels of depressive symptoms are present in approximately 1 out of 5 patients with HF. Depression is associated with poor quality of life and a greater than 2-fold risk of clinical HF progression and mortality. The biobehavioral mechanisms accounting for these adverse outcomes include biological processes (elevated neurohormones, autonomic nervous system dysregulation, and inflammation) and adverse health behaviors (physical inactivity, medication nonadherence, poor dietary control, and smoking). Depression often remains undetected because of its partial overlap with HF-related symptoms and lack of systematic screening. Behavioral and pharmacologic antidepressive interventions commonly result in statistically significant but clinically modest improvements in depression and quality of life in HF, but not consistently better clinical HF or cardiovascular disease outcomes. Documentation of the biobehavioral pathways by which depression affects HF progression will be important to identify potential targets for novel integrative behavioral and pharmacologic interventions.

Significance of white blood cell count and its subtypes in patients with acute coronary syndrome

BACKGROUND

Inflammation plays a role in the pathogenesis of coronary atherosclerosis.

MATERIALS AND METHODS

Six hundred twenty-three patients with acute coronary syndrome (ACS) referred for coronary angiography for the first time in our hospital were enrolled in this study. White blood cell and its subtypes were measured on admission. The study population was divided into three groups based on total white blood cell count and followed up. Clinical end points were major adverse cardiac events (MACEs), including cardiogenic death, stroke, heart failure, non-fatal myocardial infarction, rehospitalization for angina pectoris.

RESULTS

The median age was 68 years (range 31-92) and 64.2% of the patients were men. The median white blood cell count was 6.48 x 10(9 )L(-1) (range 2.34-27.10 x 10(9 )L(-1)). The median follow-up duration was 21 months (range 1-116) and MACEs occurred in 167 patients. The multivariable Cox proportional hazards regression model revealed that neutrophil count [Relative risk = 1.098, 95% Confidence interval (CI): 1.010-1.193, P = 0.029) was a risk factor for MACEs. The logistic regression model revealed that lymphocyte count [Odds ratio (OR) = 1.075, 95% CI: 1.012-1.142, P = 0.018] and monocyte count (OR = 8.578, 95% CI: 2.687-27.381, P < 0.001) were predictive of stenosis >or= 75%; Neutrophil proportion (OR = 1.060, 95% CI: 1.007-1.115, P = 0.026), monocyte count (OR = 12.370, 95% CI: 1.298-118.761, P = 0.029) were predictive of the presence of multivessel disease. Kaplan-Meier analysis of short-term and long-term cumulative survival showed no significant statistical differences among three groups.

CONCLUSIONS

Neutrophil count adds prognostic information to MACEs in ACS. Monocyte count and lymphocyte count are predictive of severity of coronary atherosclerosis.

Common genetic contributions to depressive symptoms and inflammatory markers in middle-aged men: the Twins Heart Study

OBJECTIVE

To examine the extent to which a common genetic pathway is also involved in the relationship between depressive symptoms, in the absence of major depressive disorder (MDD), and inflammation. Recent data suggested that MDD and inflammation share common genes.

METHODS

We recruited 188 male twins from the Vietnam Era Twin Registry who were free of symptomatic coronary artery disease and MDD, with mean +/- standard deviation (SD) age of 55 +/- 2.75 years, including 54 monozygotic and 40 dizygotic twin pairs. These pairs were assessed for two inflammatory markers, interleukin (IL)-6 and C-reactive protein (CRP). Current depressive symptoms were measured with the Beck Depression Inventory-II. Generalized estimating equations were used to examine the phenotypic association between depression and inflammatory markers. Biometrical genetic modeling was performed to estimate the genetic and environmental contributions to this association.

RESULTS

An association was observed between severity of current depressive symptoms and increased levels of inflammatory markers (p < .001 for IL-6 and p = .005 for CRP). After adjustment for other factors, the association was slightly attenuated but remained statistically significant for IL-6 (p = .002). The heritability of IL-6, CRP, and depressive symptoms were estimated as 0.37, 0.65, and 0.48, respectively. Genetic modeling found a significant genetic correlation between IL-6 and depressive symptoms (r(G) = 0.22, p = .046), indicating that about 66% of the covariance between them can be explained by shared genetic influences.

CONCLUSIONS

Current depressive symptoms are significantly correlated with inflammatory markers. This covariation is due, in large part, to genes that are common to depressive symptoms and inflammation.

Depressive symptoms and the regulation of proinflammatory cytokine expression in patients with coronary heart disease

OBJECTIVE

Depressive symptoms increase the risk of morbidity and mortality in patients with coronary heart disease (CHD). Mounting evidence indicates that inflammatory processes may underlie this association. This study examined whether depressive symptoms are associated with the dysregulation of inflammatory cytokine production in response to an in vitro infectious challenge.

METHODS

Forty-one patients with CHD were enrolled 3 months or more after an acute myocardial infarction or revascularization procedure. Depressive symptoms were assessed through self-report and interviewer ratings. Cytokine production was measured after white blood cells were cultured in vitro with endotoxin in the presence of varying concentrations of dexamethasone.

RESULTS

Depressive symptoms were not associated with the quantity of in vitro inflammatory cytokine production. However, to the extent that they reported symptoms of depression, patients showed greater sensitivity to the anti-inflammatory properties of glucocorticoids. This was manifested by increased suppression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) production by dexamethasone.

CONCLUSIONS

Increased sensitivity to glucocorticoid inhibition could render depressed patients vulnerable to latent infections and inflammatory processes that accelerate the progression of cardiac disease.

The role of immune system parameters in the relationship between depression and coronary artery disease

The relationship between depressive symptoms and coronary artery disease (CAD) is mediated in part by immune system parameters. This review describes research on the psychoneuroimmunological pathways accounting for the association between depression and CAD, and addresses conceptual and methodological issues. Relationships between central nervous system correlates of depression and immune system parameters are bidirectional and are mediated via neurohormonal and parasympathetic pathways. Evidence suggests that these associations can be affected by a) the clinical characteristics of depression (e.g., typical depression versus atypical depression and exhaustion), b) the duration and severity of depressive symptoms, and c) the stage of underlying CAD. Depressive symptoms are hypothesized to affect primarily the transition from stable CAD to acute coronary syndromes via plaque activation and prothrombotic processes, and may play an additional role in the response to injury at early stages of coronary atherosclerosis.

Relation of depressive symptoms to C-reactive protein and pathogen burden (cytomegalovirus, herpes simplex virus, Epstein-Barr virus) in patients with earlier acute coronary syndromes

Despite mounting evidence that depressive symptoms increase the risk of morbidity and mortality in patients who have coronary artery disease, little is known about the biologic mechanisms that underlie this association. This study examined whether depressive symptoms are associated with markers of infection and inflammation that have been implicated in the pathogenesis of coronary artery disease. Sixty-five patients who were recovering from an acute coronary syndrome were enrolled (63% men; mean age 61 years, 90% white). Depressive symptoms were assessed through self-report and observer ratings; the inflammatory molecules C-reactive protein, interleukin-6, and tumor necrosis factor-alpha were measured in serum, as were antibody titers to 3 latent viruses associated with atherosclerosis. Patients who had more severe depressive symptoms exhibited higher levels of C-reactive protein (r = 0.27, p = 0.03) and higher rates of seropositivity to the latent viruses (r = 0.41, p = 0.001). These effects were large in magnitude: patients in the highest tertile of the depression distribution had C-reactive protein levels >50% higher than did patients in the middle and lowest tertiles; they also were 2 times as likely to show evidence of infection with all 3 latent viruses. Disparities in the extent, severity, or management of cardiac disease were not responsible for these associations. These findings provide evidence that depressive symptoms are associated with increases in C-reactive protein and pathogen burden in patients who have coronary artery disease. In doing so, they highlight a mechanism through which depressive symptoms might foster morbidity and mortality among patients who have cardiac disease.

The inflammatory response is an integral part of the stress response: Implications for atherosclerosis, insulin resistance, type II diabetes and metabolic syndrome X

In previous publications, we presented the hypothesis that repeated episodes of acute or chronic psychological stress could induce an acute phase response (APR) and subsequently a chronic inflammatory process such as atherosclerosis. In this paper, that hypothesis, namely that such stress can induce an APR and inflammation, has been extended to include a chronic inflammatory process(s), characterized by the presence of certain cytokines and acute phase reactants (APR), which is associated with certain metabolic diseases. The loci of origin of these cytokines, particularly interleukin 6 (IL-6), and their induction, has been considered. Evidence is presented that the liver, the endothelium, and fat cell depots are the primary sources of cytokines, particularly IL-6, and that IL-6 and the acute phase protein (APP), C-reactive protein (CRP), are strongly associated with, and likely play a dominant role in, the development of this inflammatory process which leads to insulin resistance, non-insulin dependent diabetes mellitus type II, and Metabolic syndrome X. The possible role of psychological stress and the major stress-related hormones as etiologic factors in the pathogenesis of these metabolic diseases, as well as atherosclerosis, is discussed. The fact that stress can activate an APR, which is part of the innate immune inflammatory response, is evidence that the inflammatory response is contained within the stress response or that stress can induce an inflammatory response. The evidence that the stress, inflammatory, and immune systems all evolved from a single cell, the phagocyte, is further evidence for their intimate relationship which almost certainly was maintained throughout evolution.

The integration of cardiovascular behavioral medicine and psychoneuroimmunology: new developments based on converging research fields

The immune system plays a role in the progression of coronary artery diseases and its clinical manifestations as acute coronary syndromes. It is well established that psychological factors can act as risk factors for acute coronary syndromes. This review describes psychoneuroimmunological pathways involved in coronary disease progression and documents that the stage of coronary disease is a major determinant of pathophysiological mechanisms accounting for the association between psychological risk factors, immune system parameters, and acute coronary syndromes. Chronic psychological risk factors (e.g., hostility and low socioeconomic status) are important at early disease stages, episodic factors (e.g., depression and exhaustion) are involved in the transition from stable to unstable atherosclerotic plaques, and acute psychological triggers (e.g., mental stress and anger) can promote myocardial ischemia and plaque rupture. The psychoneuroimmunological pathways are described for each of these three types of psychological risk factors for acute coronary syndromes.

Psychological factors correlate meaningfully with percent-monocytes among acute coronary syndrome patients

Recent research demonstrates the importance of inflammatory parameters in the etiology and prognosis of the acute coronary syndrome (ACS). This study explored relations between psychological factors and immunological parameters routinely measured among ACS patients. Forty-two ACS patients completed questionnaires assessing perceived-control, emotional support, hostility, and life-events 2-4 days after hospitalization. Data on total leukocytes and percentages (%) of monocytes, %neutrophils, and %lymphocytes upon admission to hospital were collected from computerized medical charts as well as various biomedical information and risk-factors (e.g., diagnosis, left-ventricle-LV functioning, smoking, and hypertension). Of all significant biomedical variables, LV-function and arrival-time correlated uniquely with total leukocytes. Controlling for LV-function and arrival-time, hostility and life-events positively correlated with %monocytes, and perceived-control and emotional-support inversely correlated with %monocytes. Emotional-support was positively correlated and life-events were negatively correlated with %neutrophils. Macrophages play a pivotal role in plaque instability, the trigger of an ACS. This initiating role, and our finding of a relationship between recruitment of monocytes and a poor psychosocial profile, predictive of ACS, are consistent with a PNI component in the pathophysiology of ACS.

Allostatic load and work conditions

Adverse work characteristics and poor social support have been associated with an increased risk for cardiovascular disease and other adverse health outcomes in otherwise apparently healthy adults. We undertook a cross-sectional study to evaluate the relationship between objective health status and work characteristics in industrial workers in Germany. Volunteers (n=324) were recruited from a representative random sample (n=537) of employees of an airplane manufacturing plant. Psychosocial work characteristics were assessed by the 52-item, 13-subscale salutogenetic subjective work analysis (SALSA) questionnaire, which assesses potentially salutogenic and pathogenic conditions. Factor analysis revealed three factors: decision latitude, job demands and social support. Biological health status was determined by the revised allostatic load score with 14 components: body-mass index, waist-to-hip ratio; systolic and diastolic blood pressure; plasma levels of C-reactive protein (CRP), tumor-necrosis factor-alpha, HDL, cholesterol, dehydroepiandrosterone sulfate; glycosylated hemoglobin; urinary cortisol, epinephrine, norepinephrine, and albumin. Score points were given for values in the high-risk quartile (maximum=14). General linear models revealed that older individuals and men had significantly higher allostatic load scores than younger participants or women. Of the SALSA factors, only job demands related significantly to allostatic load. The effect of demands was stronger in older individuals. Post-hoc analysis showed possible positive associations between high job demands and blood pressure or CRP, and between low social support and nocturnal excretion of cortisol or plasma levels of CRP. We conclude that this cross-sectional study on industrial employees found a weak association between a health summary score based on objective medical data and self-reported adverse work characteristics.

Vagal cardiac control throughout the day: the relative importance of effort-reward imbalance and within-day measurements of mood, demand and satisfaction

The effects of variables derived from a work stress theory (the effort-reward imbalance theory) on the power in the high frequency (HF_HRV) band of heart rate (0.14-0.40 Hz) throughout a work day, were determined using multilevel analysis. Explanatory variables were analysed at two levels: at the lowest level (within-day level), the effects of positive mood, negative mood, demand, satisfaction, demand-satisfaction ratio, and time of day were assessed. At the highest level (the subject level), the effects of sleep quality, effort, reward, effort-reward imbalance, need for control, type of work (profession), negative affectivity, gender and smoking on HF_HRV were assessed. Need for control has a negative effect on HF_HRV after controlling for time of day effects, i.e. subjects with a high need for control have a lower vagal control of the heart. In the long run, these subjects may be considered to be at increased health risk, because they have less of the health protective effects of vagal tone. The interaction between effort-reward imbalance and time of day has a positive effect on HF_HRV, i.e. the cardiac vagal control of subjects with a high effort-reward imbalance increases as the day progresses. It is discussed that this probably reflects reduced effort allocation, ensuing from disengagement from the work demands.

Theory-Driven Interventions in Psychoneuroimmunology and HIV-1 Infection

Psychoneuroimmunology (PNI) is a rapidly evolving multidisciplinary field founded on the premise that psychosocial factors, the central nervous system, and the immune system are intimately linked. Following publication of scientific evidence supporting this link, a number of animal and human studies have been published, both inside and outside the area of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome. These studies support the existence of bidirectional feedback mechanisms operating between the brain and the immune system. To date, however, there is no all-encompassing model that predicts individual differences in the relationship among psychosocial factors, immunologic measures, and clinical disease progression in HIV type 1 (HIV-1) infection. This variability in human response has been explained by a number of cofactors (host as well as environmental) that appear to accelerate the course of the disease. Since psychosocial factors are highly amenable to behavioral interventions, several models for intervention research have been proposed to evaluate whether such interventions can enhance immune functioning, thereby curtailing disease progression. Examination of these interventions in the context of PNI and HIV-1 infection, however, is rather limited. Therefore, researchers and clinicians must not only consider conceptualizations and paradigms in this area of research, but also focus on empirically testable, theory-driven models that allow for the unique characteristics of individual patients.

Association between burnout at work and leukocyte adhesiveness/aggregation

OBJECTIVE

This study examined whether burnout at work is associated with leukocyte adhesiveness/aggregation (LAA), a phenomenon known to be affected by stress.

METHODS

The LAA levels of 179 employees (68 men and 111 women) of Tel Aviv University were determined when the employees underwent their annual routine medical checkup. Blood pressure and toxic chemical exposure were also measured, and background data were retrieved from medical records. Information on burnout and somatic complaints (known to be a general marker of stress) was collected through a self-report questionnaire.

RESULTS

Total burnout and each of its subcomponents, emotional exhaustion, chronic fatigue, and cognitive weariness, was significantly associated with LAA levels, even after controlling for age, sex, and educational level. Burnout and somatic complaints intercorrelated positively, but somatic complaints were not significantly associated with LAA levels before or after controlling for the above possible confounders.

CONCLUSIONS

Burnout was positively associated with LAA levels. This finding is consistent with the growing evidence of the negative impact of burnout on physical health. The lack of an association between somatic complaints and LAA levels reinforces the claim that burnout and stress are two different concepts.

A Research Derived Bereavement Support Group Technique for the Hiv-1 Infected

A brief, semi-structured, bereavement support group for HIV seropositive and at risk homosexual men suffering a recent loss of a close friend or lover is described. The intervention employed a set of topics to stimulate group discussion. These topics were organized into three phases: making contact, venting of emotion, and “moving on.” Our predictive theoretical model integrating life stressor appraisal, social support availability, and active coping was incorporated. Therapeutic foci are active monitoring of stressor load; accurate stressor appraisal; extending, using and evaluating one's social support network; and selection of adaptive coping strategies. Three vignettes illustrate the integration of the research protocol with clinical issues. Implications for clinical care are discussed.