Effects of chronic stress on beta-adrenergic receptors in the homeless

The growing field of immunometabolism and exercise: Key findings in the last 5 years

This perspective review highlights the impact of physical exercise on immunometabolic responses in the past 5 years. Understanding immunometabolism as a part of immunological research is essential. Furthermore, the roles of both acute and chronic effects of physical exercise on health, aging, and chronic diseases in immunometabolic changes should be elaborated. In immune cells, β2 adrenergic signaling stimulates the preferential mobilization of inflammatory phenotypes, such as CD16⁺ monocytes and CD8⁺ T cells, into the bloodstream after a physical exercise session. The mobilization of immune cells is closely related to the availability of energetic substrates for the cell and mechanisms associated with the uptake and oxidation of fatty acids and glucose. These cells, especially senescent T cells, are mobilized to the peripheral tissues and undergo apoptotic signaling, stimulating the creation of a "vacant space" where new cells will be matured and replaced in the circulation. This results in the upregulation of the expression and secretion of anti-inflammatory cytokines (IL-10 and IL-1ra), leading to increased regulatory immune cells that provide immunoregulatory properties. Thus, we suggest that a significant nutrient available to the cell will favor oxidative metabolism, augment ATP production, and consequently maintain the immune cells in their quiescent state, as well as promote rapid activation function. Therefore, based on the studies discussed in this perspective review, we highlight the importance of performing moderate-intensity continuous and high-intensity intermittent aerobic exercises, due to a higher magnitude of energetic demand and release of anti-inflammatory cytokines (IL-6 and IL-10).

Exercise and adrenergic regulation of immunity

Exercise training has a profound impact on immunity, exerting a multitude of positive effects in indications such as immunosenescence, cancer, viral infections and inflammatory diseases. The immune, endocrine and central nervous systems work in a highly synergistic manner and it has become apparent that catecholamine signaling through leukocyte β-adrenergic receptors (β-ARs) is a key mechanism by which exercise mediates improvements in immune function to help mitigate numerous disease conditions. Central to this is the preferential mobilization and redistribution of effector lymphocytes with potent anti-viral and anti-tumor activity, their interaction with muscle-derived cytokines, and the effects of catecholamine signaling on mitochondrial biogenesis, immunometabolism and the resulting inflammatory response. Here, we review the impact of acute and chronic exercise on adrenergic regulation of immunity in the context of aging, cancer, viral infections and inflammatory disease. We also put forth our contention that exercise interventions designed to improve immunity, prevent disease and reduce inflammation should consider the catecholamine-AR signaling axis as a therapeutic target and ask whether or not the adrenergic signaling machinery can be 'trained' to improve immune responses to stress, disease or during the normal physiological process of aging. Finally, we discuss potential strategies to augment leukocyte catecholamine signaling to boost the effects of exercise on immunity in individuals with desensitized β-ARs or limited exercise tolerance.

Glucocorticoid resistance and β2-adrenergic receptor signaling pathways promote peripheral pro-inflammatory conditions associated with chronic psychological stress: A systematic review across species

Activation of the HPA-axis and SNS are widely accepted to link chronic stress with elevated levels of peripheral pro-inflammatory markers in blood. Yet, empirical evidence showing that peripheral levels of glucocorticoids and/or catecholamines mediate this effect is equivocal. Recent attention has turned to the possibility that cellular sensitivity to these ligands may contribute to inflammatory mediators that accompany chronic stress. We review current evidence for the association of chronic stress with glucocorticoid receptor (GR) and β-adrenergic receptor (β-AR) signaling sensitivity. Across 15 mouse, 7 primate, and 19 human studies, we found that chronic stress reliably associates with downregulation in cellular GR sensitivity, alterations in intracellular β-AR signaling, and upregulation in pro-inflammatory biomarkers in peripheral blood. We also present evidence that alterations in GR and β-AR signaling may be specific to myeloid progenitor cells such that stress-related signaling promotes release of cells that are inherently less sensitive to glucocorticoids and differentially sensitive to catecholamines. Our findings have broad implications for understanding mechanisms by which chronic stress may contribute to pro-inflammatory phenotypes.

Cardiovascular Disease and Homelessness

Cardiovascular disease (CVD) is a major cause of death among homeless adults, at rates that exceed those in nonhomeless individuals. A complex set of factors contributes to this disparity. In addition to a high prevalence of cigarette smoking and suboptimal control of traditional CVD risk factors such as hypertension and diabetes, a heavy burden of nontraditional psychosocial risk factors like chronic stress, depression, heavy alcohol use, and cocaine use may confer additional risk for adverse CVD outcomes beyond that predicted by conventional risk estimation methods. Poor health care access and logistical challenges to cardiac testing may lead to delays in presentation and diagnosis. The management of established CVD may be further challenged by barriers to medication adherence, communication, and timely follow-up. The authors present practical, patient-centered strategies for addressing these challenges, emphasizing the importance of multidisciplinary collaboration and partnership with homeless-tailored clinical programs to improve CVD outcomes in this population.

Exploring a post-traumatic stress disorder paradigm in Flinders sensitive line rats to model treatment-resistant depression I: bio-behavioural validation and response to imipramine

OBJECTIVE

Co-morbid depression with post-traumatic stress disorder (PTSD) is often treatment resistant. In developing a preclinical model of treatment-resistant depression (TRD), we combined animal models of depression and PTSD to produce an animal with more severe as well as treatment-resistant depressive-like behaviours.

METHODS

Male Flinders sensitive line (FSL) rats, a genetic animal model of depression, were exposed to a stress re-stress model of PTSD [time-dependent sensitisation (TDS)] and compared with stress-naive controls. Seven days after TDS stress, depressive-like and coping behaviours as well as hippocampal and cortical noradrenaline (NA) and 5-hydroxyindoleacetic acid (5HIAA) levels were analysed. Response to sub-chronic imipramine treatment (IMI; 10 mg/kg s.c.×7 days) was subsequently studied.

RESULTS

FSL rats demonstrated bio-behavioural characteristics of depression. Exposure to TDS stress in FSL rats correlated negatively with weight gain, while demonstrating reduced swimming behaviour and increased immobility versus unstressed FSL rats. IMI significantly reversed depressive-like (immobility) behaviour and enhanced active coping behaviour (swimming and climbing) in FSL rats. The latter was significantly attenuated in FSL rats exposed to TDS versus unstressed FSL rats. IMI reversed reduced 5HIAA levels in unstressed FSL rats, whereas exposure to TDS negated this effect. Lowered NA levels in FSL rats were sustained after TDS with IMI significantly reversing this in the hippocampus.

CONCLUSION

Combining a gene-X-environment model of depression with a PTSD paradigm produces exaggerated depressive-like symptoms that display an attenuated response to antidepressant treatment. This work confirms combining FSL rats with TDS exposure as a putative animal model of TRD.

Symptoms of anxiety and depression are related to cardiovascular responses to active, but not passive, coping tasks

Objective:

Anxiety and depression have been linked to blunted blood pressure (BP) and heart rate (HR) reactions to mental stress tests; however, most studies have not included indices of underlying hemodynamics nor multiple stress tasks. This study sought to examine the relationships of anxiety and depression with hemodynamic responses to acute active and passive coping tasks.

Methods:

A total of 104 participants completed the Hospital Anxiety and Depression Scales and mental arithmetic, speech, and cold pressor tasks while BP, HR, total peripheral resistance, and cardiac output (CO) were assessed.

Results:

After adjustment for traditional risk factors and baseline cardiovascular activity, depression scores were negatively associated with systolic BP, HR, and CO responses to the mental arithmetic task, while anxiety scores were inversely related to the systolic BP response to mental arithmetic.

Conclusion:

High anxiety or depression scores appear to be associated with blunted cardiac reactions to mental arithmetic (an active coping task), but not to the cold pressor test or speech tasks. Future research should further examine potential mechanisms and longitudinal pathways relating depression and anxiety to cardiovascular reactivity.

Clinical trial registration number:

TCTR20160208004

The Textuality of Stress

Stress is a key term in health psychology, marking both conceptual possibilities and legislative failures. Rather than add a further global theory of stress, the term is examined as it operates in numerous kinds of practices. Drawing on qualitative material from varying sources I place emphasis on the role of concern and understanding in the definition of stress as the matter at hand. A discursive approach is used to worry the opposition of scientific and cultural practice in stress research and point instead to the notion of specific problematizations that appear in the rich fabric of the term's definition and description. I propose that attention to the details of a textuality of stress marks a step towards a 'modest' health psychology.

Norepinephrine preferentially modulates memory CD8 T cell function inducing inflammatory cytokine production and reducing proliferation in response to activation

BACKGROUND

Norepinephrine (NE) is one of the primary catecholamines of the sympathetic nervous system released during a stress response and plays an important role in modulating immune function. NE binds to the adrenergic receptors on immune cells, including T cells, resulting in either suppressed or enhanced function depending on the type of cell, activation status of the cell, duration of NE exposure and concentration of NE. Here, we aim to analyze the effects of NE on the functionality of naïve (Tn), central memory (Tcm) and effector memory (Tem) CD8 T cells.

METHODS

We isolated CD8 T cell subsets from healthy human adults and treated cells in vitro with NE (1×10(-6)M) for 16h; we then stimulated NE treated and untreated CD8 T cell subsets with antibodies for CD3 and CD28 for 24 and 72h. We assessed the level of beta-2 adrenergic receptor (ADRB2) expression in these cells as well as global gene expression changes in NE treated Tcm cells by microarray analysis. Altered expressed genes after NE treatment were identified and further confirmed by RT-qPCR, and by ELISA for protein changes. We further determined whether the observed NE effects on memory CD8 T cells are mediated by ADRB2 using specific adrenergic receptor agonist and antagonists. Finally, we examined the levels of mRNA and protein of the NE-induced genes in healthy adults with high serum levels of NE (>150pg/mL) compared to low levels (<150pg/mL).

RESULTS

We found that memory (Tcm and Tem) CD8 T cells expressed a significantly higher level of ADRB2 compared to naïve cells. Consequently, memory CD8 T cells were significantly more sensitive than naïve cells to NE induced changes in gene expressions in vitro. Global gene expression analysis revealed that NE induced an elevated expression of inflammatory cytokines and chemokines in resting and activated memory CD8 T cells in addition to a reduced expression of growth-related cytokines. The effects of NE on memory CD8 T cells were primarily mediated by ADRB2 as confirmed by the adrenergic receptor agonist and antagonist assays. Finally, individuals with high serum levels of NE had similar elevated gene expressions observed in vitro compared to the low NE group.

CONCLUSIONS

Our results demonstrate that NE preferentially modulates the functions of memory CD8 T cells by inducing inflammatory cytokine production and reducing activation-induced memory CD8 T cell expansion.

Chronic treatment with prazosin or duloxetine lessens concurrent anxiety-like behavior and alcohol intake: evidence of disrupted noradrenergic signaling in anxiety-related alcohol use

BACKGROUND

Alcohol use disorders have been linked to increased anxiety, and enhanced central noradrenergic signaling may partly explain this relationship. Pharmacological interventions believed to reduce the excitatory effects of norepinephrine have proven effective in attenuating ethanol intake in alcoholics as well as in rodent models of ethanol dependence. However, most preclinical investigations into the effectiveness of these drugs in decreasing ethanol intake have been limited to acute observations, and none have concurrently assessed their anxiolytic effects. The purpose of these studies was to examine the long-term effectiveness of pharmacological interventions presumed to decrease norepinephrine signaling on concomitant ethanol self-administration and anxiety-like behavior in adult rats with relatively high levels of antecedent anxiety-like behavior.

METHODS

Adult male Long-Evans rats self-administered ethanol on an intermittent access schedule for eight to ten weeks prior to being implanted with osmotic minipumps containing either an a1-adrenoreceptor antagonist (prazosin, 1.5 mg/kg/day), a β1/2-adrenoreceptor antagonist (propranolol, 2.5 mg/kg/day), a serotonin/norepinephrine reuptake inhibitor (duloxetine, 1.5 mg/kg/day) or vehicle (10% dimethyl sulfoxide). These drugs were continuously delivered across four weeks, during which animals continued to have intermittent access to ethanol. Anxiety-like behavior was assessed on the elevated plus maze before treatment and again near the end of the drug delivery period.

RESULTS

Our results indicate that chronic treatment with a low dose of prazosin or duloxetine significantly decreases ethanol self-administration (P < 0.05). Furthermore, this decrease in drinking is accompanied by significant reductions in the expression of anxiety-like behavior (P < 0.05).

CONCLUSIONS

These findings suggest that chronic treatment with putative inhibitors of central noradrenergic signaling may attenuate ethanol intake via a reduction in anxiety-like behavior.

Stress, ageing and their influence on functional, cellular and molecular aspects of the immune system

The immune response is essential for keeping an organism healthy and for defending it from different types of pathogens. It is a complex system that consists of a large number of components performing different functions. The adequate and controlled interaction between these components is necessary for a robust and strong immune response. There are, however, many factors that interfere with the way the immune response functions. Stress and ageing now consistently appear in the literature as factors that act upon the immune system in the way that is often damaging. This review focuses on the role of stress and ageing in altering the robustness of the immune response first separately, and then simultaneously, discussing the effects that emerge from their interplay. The special focus is on the psychological stress and the impact that it has at different levels, from the whole system to the individual molecules, resulting in consequences for physical health.

A systematic review of genetic influences on coping

Coping refers to the way that an individual manages stress. Coping strategies vary; for example, problem-focused coping is directed at reducing or removing a stressor, while emotion-focused coping is directed more at managing reactions that accompany the stressor. How individuals cope with stress can impact their health, but the physiological effects of coping are not well understood. The field of genetics provides tools that could help illuminate the physiology of coping. This review of the literature was conducted to determine what is currently known about the phenotype of coping from a genetic perspective. PubMed, HubMed, PsychInfo, Medline, Scopus, and Google Scholar databases were used to conduct the search, and reference lists were reviewed to identify additional publications. Only studies that measured coping style or a coping domain specifically, were written in English language, and were human-subject focused were included in the review. We identified 19 studies that met these criteria, and 2 types of genetic studies emerged for the review: heritability (n = 9) and candidate gene association (n = 10) studies. Heritability estimates of .68-.76 support a nonadditive genetic component to coping. Replication of association was found for the serotonin transporter and adrenergic receptor beta 2 genes. In addition to finding evidence supporting a role for genetic variability with coping phenotype, it is worth noting that the review revealed a lack of consistency in instruments used to phenotype coping across studies.

Leukocyte ß-adrenergic receptor sensitivity and depression severity in patients with heart failure

OBJECTIVES

Clinical outcomes are worse for patients with heart failure (HF) and elevated depression symptoms. Depression-related sympathoimmune dysregulation may be one mechanism leading to poorer HF prognosis. Sympathetically mediated adrenergic activity is known to regulate immune activity via β-adrenergic receptors (β-ARs). However, studies show conflicting relationships between leukocyte β-AR sensitivity and depression symptoms. The aim of this study was to determine in patients with HF the relationship of leukocyte β-AR sensitivity with two diverse measures of depression, self-report questionnaire versus clinical diagnostic interview.

METHODS

Patients with HF (N = 73, mean [standard deviation] age = 56.3 [13.0]) completed the Beck Depression Inventory-1A and a modified Structured Clinical Interview for the DSM-IV. Leukocyte β-AR sensitivity was determined from isoproterenol-stimulated cyclic adenosine monophosphate levels; plasma norepinephrine and epinephrine were also assessed.

RESULTS

Patients with major depression determined by Structured Clinical Interview for the DSM-IV had significantly higher β-AR sensitivity than did nondepressed patients (F(6,72) = 9.27, p = .003, η = 0.12). The Beck Depression Inventory-1A revealed a more complex relationship. Minimal, mild, and moderate-to-severe depression symptom groups had significant differences in β-AR sensitivity (F(7,72) = 7.03, p = .002, η = 0.18); mild symptoms were associated with reduced β-AR sensitivity and moderate-to-severe symptoms with higher β-AR sensitivity compared with patients with minimal depressive symptoms.

CONCLUSIONS

Clinical depression was associated with elevated β-AR sensitivity in patients with HF. By deconstructing depression measurements, a greater depth of information may be garnered to potentially reveal subtypes of depression symptoms and their relation to β-AR sensitivity.

Interactions between social/ behavioral factors and ADRB2 genotypes may be associated with health at advanced ages in China

BACKGROUND

Existing literature indicates that ADRB2 gene is associated with health and longevity, but none of previous studies investigated associations of carrying the ADRB2 minor alleles and interactions between ADRB2 genotypes and social/behavioral factors(GxE) with health outcomes at advanced ages. This study intends to fill in this research gap.

METHOD

We conducted an exploratory analysis, using longitudinal survey phenotype/genotype data from 877 oldest-old aged 90+. To estimate association of GxE interactions with health outcome, adjusted for the potential correlation between genotypes and social/behavioral factors and various other potentially confounding factors, we develop and test an innovative three-step procedure which combines logistic regression and structural equation methods.

RESULTS

Interaction between regular exercise and carrying rs1042718 minor allele is significantly and positively associated with good cognitive function; interaction between regular exercise and carrying rs1042718 or rs1042719 minor allele is significantly and positively associated with self-reported good health; and interaction between social-leisure activities and carrying rs1042719 minor allele is significantly and positively associated with self-reported good health. Carrying rs1042718 or rs1042719 minor alleles is significantly and negatively associated with negative emotion, but the ADRB2 SNPs are not significantly associated with cognitive function and self-reported health. Our structural equation analysis found that, adjusted for the confounding effects of correlation of the ADRB2 SNPs with negative emotion, interaction between negative emotion and carrying rs1042718 or rs1042719 minor allele is significantly and negatively associated with cognitive function. The positive association of regular exercise and social-leisure activities with cognitive function and self-reported health, and negative association of negative emotion with cognitive function, were much stronger among carriers of rs1042718 or rs1042719 alleles, compared to the non-carriers.

CONCLUSIONS

The results indicate significant positive associations of interactions between social/behavioral factors and the ADRB2 genotypes with health outcomes of cognitive function and self-reported health, and negative associations of carrying rs1042718 or rs1042719 minor alleles with negative emotion, at advanced ages in China. Our findings are exploratory rather than causal conclusions. This study implies that near-future health promotion programs considering individuals' genetic profiles, with appropriate protection of privacy/confidentiality, would yield increased benefits and reduced costs to the programs and their participants.

Association of in vivo β-adrenergic receptor sensitivity with inflammatory markers in healthy subjects

OBJECTIVE

Several stress-related states and conditions that are considered to involve sympathetic overactivation are accompanied by increased circulating levels of inflammatory immune markers. Prolonged sympathetic overactivity involves increased stimulation of the β-adrenergic receptor (β-AR). Although prior research suggests that one mechanism by which sympathetic stimulation may facilitate inflammation is via β-AR activation, little work has focused on the relationship between circulating inflammatory immune markers and β-AR function within the human body (in vivo). We examined whether decreased β-AR sensitivity, an indicator of prolonged β-adrenergic overactivation and a physiological component of chronic stress, is related to elevated levels of inflammatory immune markers.

METHODS

Ninety-three healthy participants aged 19 to 51 years underwent the chronotropic 25 dose isoproterenol test to determine in vivo β-AR function. Circulating levels of C-reactive protein, interleukin 6, and soluble tumor necrosis factor receptor 1 were determined.

RESULTS

β-AR sensitivity was lower in people with higher C-reactive protein concentrations (r = 0.326, p = .003). That relationship remained significant after controlling for sociodemographic and health variables such as age, sex, ethnicity, body mass index, mean arterial blood pressure, heart rate, leisure-time exercise, and smoking status. No significant relationship was found between chronotropic 25 dose and interleukin 6 or soluble tumor necrosis factor receptor 1.

CONCLUSIONS

This study demonstrates a link between in vivo β-adrenergic receptor function and selected circulating inflammatory markers (CRP) in humans. Future studies in specific disease states may be promising.

Subjective social status predicts in vivo responsiveness of β-adrenergic receptors

OBJECTIVE

Several poor health outcomes, including cardiovascular risk, have been associated with both subjective social status (SSS) and sympathetic overactivity. Because prolonged sympathetic overactivation down regulates beta adrenergic receptor (β-AR) function, reduced β-AR responsiveness is considered an indicator of sympathetic overactivity and a cardiovascular risk factor. Though prior research has focused on objective social status and β-AR function, no studies have examined the association between SSS and β-AR function. We aimed to learn whether SSS predicts the in vivo responsiveness of β-ARs.

METHODS

We assessed the chronotropic 25 dose (CD25), an in vivo marker of β-AR responsiveness, in 94 healthy participants. The MacArthur scales of subjective social status were used to assess SSS in the U.S.A. (SSS-USA) and in the local community (SSS-C). Objective social status was analyzed by calculating the Hollingshead two-factor index.

RESULTS

β-AR responsiveness was reduced (as indicated by higher CD25 values) in participants with lower SSS-USA (p = .007) and lower SSS-C (p < .001). The relationship between CD25 and SSS was particularly robust with respect to SSS-C. Hierarchical regression analyses revealed that SSS-C remained a significant predictor of CD25 (p < .001) and accounted for 14% of the total variance (32%) in CD25 after adjusting for sociodemographic variables (age, ethnicity, gender), health factors (exercise, smoking status, body mass index) and objective social status.

CONCLUSION

Our results indicate that β-AR function may be an important component of the link between SSS and health.

Effects of dipping and psychological traits on morning surge in blood pressure in healthy people

Despite the role of anxiety, depression and hostility in the pathogenesis of cardiovascular diseases, their impact on two significant cardiovascular risk factors, nocturnal dipping and morning surge in blood pressure (MSBP), are largely ignored and primarily studied in clinical populations. This study examined the effects of dipping and psychological traits on MSBP in healthy people. Nocturnal dipping and MSBP were derived from 24-h ambulatory BP obtained in 77 men and 79 women, mean age 32.8 (s.d.: 7.4). Differences in depression, anxiety and hostility were examined by questionnaires. Higher levels of dipping (P<0.0001) and depressive symptoms (P=0.01) independently contributed to increased MSBP. Dipping interacts with depression (P=0.04), hostility (P=0.01) and anxiety (P=0.04) in determining MSBP. Low dippers with higher scores on the psychological traits showed higher MSBP than high dippers. A significant MSBP interaction was found between sex and depressive symptoms (P=0.05), anxiety (P<0.0001) and hostility (P=0.01) with higher scores associated with increased MSBP observed in males. Findings underscore depression as a predictor of MSBP independent of dipping. The clinically significant relationship between dipping and non-dipping patters, psychological traits and MSBP requires further investigation.

Depression as a potential modulator of Beta-adrenergic-associated leukocyte mobilization in heart failure patients

OBJECTIVES

the aim of this study was to determine whether depressive symptoms are related to alterations in the sensitivity of peripheral blood mononuclear cells to β-adrenergic agonists in patients with heart failure (HF) by measuring in vitro chemotaxis (CTX) to isoproterenol at rest and after acute exercise in patients with HF and controls.

BACKGROUND

clinical outcomes are worse for patients with HF presenting with symptoms of depression. Sympathetically modulated immune dysregulation associated with depression may be one mechanism leading to worse prognosis.

METHODS

seventy-seven patients with HF and 44 controls (mean age 56.4 ± 1.3 years) completed the Beck Depression Inventory and a 15-min mild-graded exercise task on a stationary bicycle. Exercise intensity was kept relative to fitness levels for all participants by gradually increasing resistance to reach a Borg scale subjective rating of 12 to 13, "somewhat hard." Plasma norepinephrine and epinephrine levels were measured before and after exercise. Chemotaxis to isoproterenol was determined by measuring in vitro peripheral blood mononuclear cell migration through a modified Boyden chamber.

RESULTS

In patients with HF, depressive symptom severity was associated with greater CTX after exercise (p = 0.001). Higher resting norepinephrine in patients with HF was also associated with increased CTX to exercise (p = 0.03).

CONCLUSIONS

patients with HF with higher depressive symptoms and norepinephrine exhibited increased peripheral blood mononuclear cell CTX to isoproterenol to mild exercise, suggesting greater β-adrenergic sensitivity. Increased immune migration in patients with HF who have elevated depressive symptoms could be associated with cardiac remodeling and HF disease progression.

Depression and anxiety: Associations with biological and perceived stress reactivity to a psychological stress protocol in a middle-aged population

BACKGROUND

Depression and anxiety have been linked to higher as well as lower reactivity to stressful circumstances. Large, population-based studies investigating the association between depression and anxiety, perceived and physiological stress responses are lacking.

METHODS

We studied 725 men and women, aged 55-60 years, from a population-based cohort, who filled out the Hospital Anxiety and Depression Scale (HADS). We performed a standardized interview on medical history and lifestyle. We measured continuous blood pressure (BP) and heart rate (HR) reactivity, saliva cortisol reactivity and perceived stress during a psychological stress protocol.

RESULTS

Albeit not statistically significant in all groups, systolic BP (SBP), diastolic BP (DBP), HR and cortisol reactivity to the psychological stress protocol were lower in those with mild-to-severe depression or anxiety symptoms and those ever clinically diagnosed with depression or anxiety, while perceived levels of stress were higher compared to those without depression or anxiety symptomatology. Maximum SBP, HR and cortisol stress responses significantly decreased and perceived stress scores significantly increased with increasing scores on the HADS depression subscale (HADS-D) and HADS anxiety subscale (HADS-A) (all P<0.05). The same held for stress responses in relation to the total HADS score (all P<0.05) and, in this case, the maximum DBP stress response was also significantly lower with an increasing HADS score (P=0.05). In addition, the maximum DBP stress response was significantly lower for those ever clinically diagnosed with depression (P=0.04). Adjusting for sex, use of anti-hypertensive medication, anti-depressant and anxiolytic medication, smoking, alcohol consumption, socio-economic status (SES) and body mass index (BMI) did not attenuate the results.

CONCLUSION

The present study results suggest that the biological stress response of middle-aged men and women who experienced depressed and anxious feelings does not completely correspond with how stressed they feel at that moment. Although differences were not substantial in all cases, response to a psychological stress protocol seemed to be decreased in the groups with experience of depressed and anxious feelings, while the perception of stress seemed to be increased.

A 5-year longitudinal study of the relationships between stress, coping, and immune cell beta(2)-adrenergic receptor sensitivity

Caring for a spouse with Alzheimer's disease (AD) is associated with overall health decline and impaired cardiovascular functioning. This morbidity may be related to the effects of caregiving stress and impaired coping on beta(2)-adrenergic receptors, which mediate hemodynamic and vascular responses and are important for peripheral blood mononuclear cell (PBMC) trafficking and cytokine production. This study investigated the longitudinal relationship between stress, personal mastery, and beta(2)-adrenergic receptor sensitivity assessed in vitro on PBMC. Over a 5-year study, 115 spousal AD caregivers completed annual assessments of caregiving stress, mastery, and PBMC beta(2)-adrenergic receptor sensitivity, as assessed by in vitro isoproterenol stimulation. Heightened caregiving stress was associated with significantly decreased receptor sensitivity, whereas greater sense of personal mastery was associated with significantly increased receptor sensitivity. These results suggest that increased stress may be associated with a desensitization of beta(2)-receptors, which may contribute to the development of illness among caregivers. However, increased mastery is associated with increased receptor sensitivity, and may therefore serve as a resource factor for improved health in this population.

Neuregulin-1 genotype moderates the association between job strain and early atherosclerosis in young men

BACKGROUND

Although it is known that a given level of strain does not induce a corresponding CHD risk in all individuals, factors that predict groups at risk have remained unclear. Neuregulin-1 (NRG-1) has various roles in the development and function of the heart and autonomic nervous system.

PURPOSE

We examined whether polymorphic variation in NRG-1 moderates the association between job strain and early atherosclerosis.

METHODS

The participants (M age = 32.5) were 349 women and 357 men derived from the population-based Cardiovascular Risk in Young Finns study. Job strain was defined as the joint effect of job demands and job control. Preclinical atherosclerosis was measured using carotid intima-media thickness (IMT) ultrasound.

RESULTS

NRG-1 single nucleotide polymorphism SNP8NRG221533 (T to C) was found to moderate the association between job strain and IMT in men (p = .04). Job strain was significantly associated with increased IMT among men with T/T genotype but not among the others. A direct association between NRG-1 and IMT was found in women.

CONCLUSIONS

Our results suggest that the effect of job strain on early atherosclerosis is dependent on NRG-1 genotype in men. Gene x Environment Interaction approach seems to offer important additional information in stress research.

Mood states, sympathetic activity, and in vivo beta-adrenergic receptor function in a normal population

The purpose of this study was to examine the relationship between mood states and beta-adrenergic receptor function in a normal population. We also examined if sympathetic nervous system activity is related to mood states or beta-adrenergic receptor function. Sixty-two participants aged 25-50 years were enrolled in this study. Mood states were assessed using the Profile of Mood States (POMS). Beta-adrenergic receptor function was determined using the chronotropic 25 dose isoproterenol infusion test. Level of sympathetic nervous system activity was estimated from 24-hr urine norepinephrine excretion. Higher tension-anxiety, depression-dejection, and anger-hostility were related to decreased beta-adrenergic receptor sensitivity (i.e., higher chronotropic 25 dose values), but tension-anxiety was the only remaining independent predictor of beta-adrenergic receptor function after controlling for age, gender, ethnicity, and body mass index (BMI). Urinary norepinephrine excretion was unrelated to either mood states or beta-adrenergic receptor function. These findings replicate previous reports that anxiety is related to decreased (i.e., desensitized) beta-adrenergic receptor sensitivity, even after controlling for age, gender, ethnicity, and body mass index.

Anxiety and beta-adrenergic receptor function in a normal population

Many studies have shown a close relationship between anxiety and beta-adrenergic receptor function in patients with anxiety disorders. This study examined the relationship between beta-adrenergic receptor function and anxiety levels in a normal population. Subjects for this study included 36 men and 44 women between the ages of 20 and 40 years whose Body Mass Index (BMI) was between 18 and 26. All of them were healthy subjects who had no previous history of medical or psychiatric illnesses. The authors measured the Spielberger State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), and Chronotropic 25 Dose (CD25) of isoproterenol, previously developed to assess in vivo beta-adrenergic receptor sensitivity. We also examined correlations between log normalized CD25 and mood states. The mean of CD25 was 2.64+/-1.37 mug and the mean of CD25 in men was significantly higher (i.e., lower beta-adrenergic receptor sensitivity) than that of women (3.26+/-1.35 vs. 2.14+/-1.17 microg; t = 3.99, p < 0.001). CD25 showed negative correlations with STAI state anxiety (r = -0.344, p = 0.002), trait anxiety (r = -0.331, p = 0.003), and BDI (r = -0.283, p = 0.011). CD25 was positively correlated with BMI (r = 0.423, p < 0.001) and age (r = 0.271, p = 0.015). In stepwise multiple regression analyses, 34% of the variance in CD25 was accounted for by sex, state anxiety, and BMI. The sensitivity of beta-adrenergic receptors increased as anxiety levels became higher in a normal population. Thus, the relationship between anxiety and beta-adrenergic receptor function in healthy subjects may be different from that of patients with anxiety disorders.

Overcommitment to work is associated with changes in cardiac sympathetic regulation

OBJECTIVE

Work stress is associated with an increased risk for cardiovascular disease (CVD). Exaggerated cardiovascular reactivity to work-related stressors or incomplete recovery after work is a proposed mechanism underlying this increase in risk. This study examined the effects of work stress on 24-hour profiles of the pre-ejection period (PEP), a measure of cardiac sympathetic activity, obtained from ambulatory measurement of the impedance cardiogram.

METHODS

A total of 67 male white-collar workers (age 47.1 +/- 5.2) underwent ambulatory monitoring on 2 workdays and 1 non-workday. Work stress was defined according to Siegrist's model as 1) a combination of high effort and low reward at work (high imbalance) or 2) an exhaustive work-related coping style (high overcommitment).

RESULTS

High overcommitment was associated with shorter absolute PEP levels during all periods on all 3 measurement days, reduced wake-to-sleep PEP differences and reduced PEP variability, as indexed by the SD.

CONCLUSIONS

Overcommitment to work was associated with an increase in basal sympathetic drive and a reduction in the dynamic range of cardiac sympathetic regulation. Both findings are compatible with the hypothesis that overcommitment induces beta-receptor down-regulation.

Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.

Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.

Moderation of physiological stress responses by personality traits and daily hassles: less flexibility of immune system responses

Previously we demonstrated that stressors varying on the dimension of mental effort and controllability have distinctive effects on cardiovascular, endocrine and immune system responses. The purpose of the present study was to relate individual differences in physiological stress responsivity to task appraisal and stress-induced mood changes (issue 1), trait characteristics (issue 2) and daily hassles (issue 3). Appraisal and mood changes did not mediate the differential effects of the stressors. The trait characteristics, aggression and external locus of control and daily hassles moderated the effect of the stressor on physiological parameters, especially immune parameters. Moreover, the moderation effect was different in the high versus the low effort stress task. High aggression, high external locus of control and more daily hassles were associated with increased reactivity in the low effort condition and decreased reactivity in the high effort condition, which is suggested to reflect less differentiated responding to changing task demands and hence, less flexibility in the immune system.

Altered lymphocyte catecholamine reactivity in mice subjected to chronic mild stress

There is considerable evidence that the sympathetic nervous system influences the immune response via activation and modulation of beta(2)-adrenergic receptors (beta(2)R). Furthermore, it has been suggested that stress has effects on the sympathetic nervous system. In the present study, we analyzed the influence of catecholamines on the reactivity of lymphocytes from mice exposed to a chronic mild stress (CMS) model of depression (CMS-animals). The effects of the CMS treatment on catecholamine and corticosterone levels and on beta(2)R lymphoid expression were also assessed. For this purpose, animals were subjected to CMS for 8 weeks. Results showed that catecholamines (epinephrine and norepinephrine) exert an inhibitory effect on mitogen-induced normal T-cell proliferation and a stimulatory effect on normal B-cell proliferation in response to selective B lymphocyte mitogens. Specific beta- and beta(2)-antagonists abolished these effects. Lymphocytes from mice subjected to CMS had an increased response to catecholamine-mediated inhibition or enhancement of proliferation in T and B cells, respectively. Moreover, a significant increase in beta(2)R density was observed in animals under CMS compared to normal animals. This was accompanied by an increment in cyclic AMP production after beta-adrenergic stimulation. On the other hand, neither catecholamine levels, determined in both urine and spleen samples, nor serum corticosterone levels showed significant variation between normal and CMS-animals. These findings demonstrate that chronic stress is associated with an increased sympathetic influence on the immune response and may suggest a mechanism through which chronic stress alters immunity.

Altered expression of autonomic neurotransmitter receptors and proliferative responses in lymphocytes from a chronic mild stress model of depression: effects of fluoxetine

We studied beta-adrenergic and muscarinic cholinergic receptor (MR) expression and proliferative response in lymphocytes from animals under chronic mild stress (CMS) model of depression (CMS animals). Animals were subjected to CMS (periods of food or water deprivation, changes in lighting conditions, tilted cage, etc.) for 12 weeks. CMS lymphocytes showed an altered mitogen-induced proliferation. CMS-B and -T lymphocytes showed an increment on beta-adrenoceptor number and on intracellular responses to a beta-agonist. CMS-T cells showed higher MR expression and lower cGMP responses than normal lymphocytes. MR were not detectable in normal B cells while CMS-B cells showed both MR expression and cGMP response. Beta and muscarinic stimulation influenced lymphocyte proliferative responses, in accordance with cAMP and cGMP responses. After 12 weeks of the CMS procedure, animals were treated with fluoxetine while the CMS procedure continued. Fluoxetine treatment reverted the alterations induced by CMS. These findings suggest a possible mechanism for the immune alterations found in depressive disorders and for the effect of fluoxetine treatment on immune response.

Consultation-liaison psychiatry and psychosomatic medicine: the company they keep

OBJECTIVE

The objectives of this review are 1) to briefly describe the parallel historical developments of consultation-liaison (C-L) psychiatry and psychosomatic medicine [corrected]; 2) to analyze the extent to which the literature of C-L psychiatry and psychosomatic medicine relate to each other, given that both fields have evolved simultaneously in the history of psychiatry; and 3) to propose possible explanations for observed publication patterns in selected C-L resources and the journal Psychosomatic Medicine.

METHODS

The quasi-citation analysis includes two segments: 1) a review of selected key C-L psychiatry references to determine the extent to which classic articles from Psychosomatic Medicine are cited; and 2) an analysis of 60 years of Psychosomatic Medicine, sampling issues from the first 5 years of each decade and all issues of the year 2000 for articles of potential relevance to C-L psychiatry. References to Psychosomatic Medicine articles in C-L resources are tallied as percentages of total references in each source. Articles in Psychosomatic Medicine are assigned to one of three categories (A, B, or C) according to their perceived relevance to C-L psychiatry, from most (A) to least (C) relevant.

RESULTS

The review of C-L sources ("basic" reading lists and reference lists of seminal articles and textbooks) revealed a wide range of Psychosomatic Medicine citations, from 0% to 27.4% (average, 7.5%). The survey of Psychosomatic Medicine sorted 1705 articles for their relevance to C-L psychiatry into category A (9.5-40.6%, average 21.3%), category B (70.4-86.3%, average 72.3%), and category C (0.7-12.1%, average 6.4%) for each half-decade for the past 60 years. The lowest number of category A articles appeared in the years 1970 to 1975, and the highest number appeared in 1950 to 1955; reciprocal results were found for category B articles. The lowest number of category C articles appeared in 1980 to 1985, and the highest number appeared in 1940 to 1945. For the six issues of 2000, the distributions of articles in categories A, B, and C are similar, continuing an upward trend beginning in 1975 of core (category A) articles. Explanations for publication patterns are speculatively related to various factors, such as a paucity of C-L research and researchers, the broad definition of C-L psychiatry, editorial policies, and the impact of World War II.

CONCLUSIONS

Although C-L psychiatry and psychosomatic medicine have common roots, the reliance of the C-L literature on classic Psychosomatic Medicine articles has varied markedly, from none to about one-quarter of its references. Nevertheless, Psychosomatic Medicine has consistently published articles of theoretical and clinical interest to C-L psychiatrists, with more than 90% of published articles considered to be of high or moderate relevance to C-L psychiatry. A far higher percentage of articles in Psychosomatic Medicine would seem to be relevant to the field of C-L psychiatry than are cited in significant C-L literature. Psychosomatic Medicine's essential focus on empirical research may dissuade the more clinically oriented C-L psychiatrists.

Inter and intra-species-related differences in the regulation of the cardiac autonomic system

The heart rate response to isoproterenol (HR-Iso), density and affinity (kd) of beta-adrenergic (beta-AR) and muscarinic (M2) receptors were compared among three rodents with different generation-life histories of confinement and of high altitude exposure. The European guinea pig (Cavia porcellus) (EGp), a laboratory animal that arrived in Europe after the Spanish Conquest of South America and the Peruvian guinea pig (C. porcellus) (PGp), a semi-wild animal that came from the altiplano to sea level at least 25 generations ago, were used for intra-species comparison. Wistar rats (WR) were used for inter-species comparison as representative of a typical sea level laboratory animal. The HR-Iso was lower in EGp than in the PGp. The PGp showed the highest beta-AR density (P < 0.0005) and the highest beta-AR kd values (P < 0.0005) when compared to both EGp and WR groups (beta-AR Bmax (fmol mg-1 prot), WR, 19 +/- 4; Egp, 34 +/- 10; PGp, 74 +/- 15. beta-AR kd (pM), WR, 24 +/- 10; Egp, 17 +/- 7; PGp, 39 +/- 14). In contrast, PGp showed lower M2 receptor density values than the EGp (P < 0.0005). The WR had the highest M2 receptor densities (M2 Bmax (fmol mg-1 prot), WR, 188 +/- 15; Egp, 147 +/- 9; PGp, 118 +/- 6 and M2 kd (pM), WR, 65 +/- 12; Egp, 67 +/- 6; PGp, 92 +/- 2). The inter and intra-species differences found may be related to their respective history of confinement rather than to their history of exposure to high altitude.

Cortisol is higher in parkinsonism and associated with gait deficit

INTRODUCTION

We propose an active pathogenic mechanism, involving circulating cortisol, in parkinsonism.

MATERIALS AND METHODS

Serum cortisol was measured in 96 subjects with idiopathic parkinsonism, 170 without, and in 17 spouses and 36 siblings of elderly sufferers with double the number of controls, all obeying inclusion/exclusion criteria.

RESULTS

Cortisol, adjusted for sampling time, was greater (17%, on average, P<0.001) in parkinsonians, but not in relatives. The central cortisol lowering effect of anti-muscarinics was seen (P=0.025). Selegiline may attenuate the disease, and parkinsonism is less frequent in tobacco smokers. Selegiline was associated with a lower cortisol (P=0.03): chronic smoking appeared (P=0.08) to be, irrespective of parkinsonism. Bowel stasis has been implicated in the pathogenesis: cortisol was higher in parkinsonians requiring laxatives (P=0.05). In controls, cortisol was lower, the longer the stride (P=0.02): in parkinsonians, this relationship was numerically reversed. A similar (P=0.01) group performance interaction was seen for deterioration, over 4 years, in gait.

CONCLUSION

Cortisol is doing harm or mirroring something which is. A common pathway for neuronal protection/rescue emerges.

Hostility and adrenergic receptor responsiveness: evidence of reduced beta-receptor responsiveness in high hostile men

We examined the relation of Cook and Medley Hostility (Ho) scores to alpha- and beta-adrenergic receptor responsiveness to pharmacological agonists in 22 normotensive and 14 hypertensives (aged 18-34) white males, matched for age and body mass. alpha-Adrenergic receptor responsiveness was measured by the phenylephrine dose required to increase mean blood pressure by 25 mmHg (PD25). beta-Adrenergic responsiveness was measured by the isoproterenol dose needed to increase heart rate by 25 bpm (CD25), and to lower systemic vascular resistance by 40% (VD40). Relative to men with low Ho scores (< or = 21), men with high Ho scores (> or = 21) showed significantly reduced vascular beta 2-adrenergic receptor responsiveness (VD40). Moreover, the decreased vascular responsiveness was more pronounced in borderline hypertensive men with high Ho scores. Ho scores were also marginally significant in predicting cardiac beta 1- and beta 2-adrenergic receptor responsiveness, such that men with high Ho scores showed decreased responsiveness as indexed by a larger CD25. Vascular alpha 1-adrenergic responsiveness was not associated with hostility. These observations suggest that hostility, alone or in conjunction with BP status, is associated with reduced cardiovascular beta-adrenergic receptor responsiveness.

The relationship between hostility and beta-adrenergic receptor physiology in health young males

OBJECTIVE

We examined the relationship between hostility and mononuclear leukocyte (MNL) beta-adrenergic receptor function in a sample of young healthy males.

METHOD

Thirty subjects were selected for having scored above 20 (N = 11) and below 14 (N = 19) on the Cook-Medley Hostility (Ho) scale. MNL beta-adrenergic receptor function was characterized in terms of receptor density (Bmax) and ligand-binding affinity (Kd) in homogenized cells, and intracellular cyclic adenosine monophosphate (cAMP) responses to saline, isoproterenol, and forskolin in whole cells. Subjects also completed the Multidimensional Anger Inventory (MAI), which assesses dimensions of anger.

RESULTS

Relative to men with low Ho scores, men with Ho scores above 20 showed lower receptor number and greater forskolin-stimulated cAMP. Moreover, high hostile men reported a greater frequency of anger, longer duration of anger, more frequent brooding, and a hostile outlook.

CONCLUSIONS

These data indicate that adrenergic receptor down-regulation is associated with hostility. This association may be linked to hostile persons' propensity for excessive and prolonged neuroendocrine responses to either psychological stressors or the experience of chronic stress associated with frequent and prolonged bouts of anger.

Plasma catecholamine and lymphocyte beta 2-adrenergic receptor alterations in elderly Alzheimer caregivers under stress

OBJECTIVE

The purpose of this study was to determine the effects of chronic stress on beta-adrenergic physiology in elderly spousal caregivers to Alzheimer patients.

METHODS

Thirty-seven elderly spousal caregivers and matched noncaregiver controls (mean age 73 years, SD = 6) were studied. Life stress categorization (presence of marked threat) covering the previous 6 months was determined using a semistructured interview based on the Psychiatric Epidemiological Research Inventory and the Life Events and Difficulties Schedule. beta 2-adrenergic receptor sensitivity (isoproterenol-stimulated cyclic AMP accumulation) and density were determined in lymphocytes.

RESULTS

Caregivers with high life stress had higher plasma norepinephrine levels (p < .04) but no change in plasma cortisol. For beta-receptor sensitivity, 30% of the variance was accounted for by high life stress rating, increased age, being male, and lower norepinephrine (p = .018); 17% of the variance in beta-receptor density was accounted for by plasma norepinephrine (p = .03).

CONCLUSIONS

The findings demonstrate that chronic high stress may be associated with changes in adrenergic physiology and may provide a mechanism through which chronic stress alters cellular immunity.

Relation between beta-adrenergic receptor density and lymphocyte proliferation associated with acute stress

The relations between acute changes in beta-adrenoreceptor density on lymphocytes and lymphocyte proliferation to a laboratory speech stressor were examined. Male participants either prepared and delivered a challenging speech task or read from a list of words. Participants engaged in the speech task, but not those involved in reading, exhibited significant increases in systolic blood pressure (an index of sympathetic nervous system arousal) and beta-adrenoreceptor density, accompanied by significant decreases in lymphocyte proliferation to pokeweed mitogen (PWM) but not concanavalin A (Con A). Increases in adrenoreceptor density significantly predicted decreases in lymphocyte activity in response to both mitogens. The increases in beta-adrenoreceptor density in the speech task condition occurred within 5 min after the baseline period, when participants were preparing for the speech task, but not yet speaking. These findings suggest that an acute stressor eliciting sympathetic nervous system activity can evoke rapid changes in beta-adrenoreceptor activity and decreases in mitogenic responses.

Psychosocial factors: role in cardiac risk and treatment strategies

Recent epidemiologic research has identified several psychosocial factors that impact unfavorably on prognosis among patients with established coronary heart disease (CHD). Several biologic and behavioral characteristics have been identified in patients with these psychosocial risk factors that are biologically plausible mediators of their adverse impact on prognosis. Several small-scale clinical trials offer encouraging evidence that both behavioral and pharmacologic interventions have the potential to ameliorate the health-damaging effects of psychosocial risk factors in patients with CHD. In this article we review the evidence on these points and offer recommendations as to how incorporation of this new knowledge into clinical care of the patient with CHD can lead to reduced mortality and morbidity rates in this population.