Effects of mood state and psychosocial functioning on plasma Interleukin-6 in adult patients before cardiac surgery

Blocking brown adipocyte β3-adrenoceptor attenuates blood-spinal cord barrier impairment and chronic postsurgical pain in a rat model of preoperative stress

Preoperative stress has been recognized as an independent risk factor for chronic postsurgical pain (CPSP). However, the underlying mechanisms of CPSP influenced by preoperative stress remain elusive. Previous studies indicated that excessive stress could induce disruption of the blood-spinal cord barrier (BSCB). We wondered whether and how BSCB involves in CPSP by using a single prolonged stress (SPS) combining plantar incision model in male rats to mimic preoperative stress-related postsurgical pain. Here, we observed that preoperative SPS-exposed rats exhibited relentless incisional pain, which was accompanied by impairment of BSCB and persistent elevation of serum IL-6. Intraperitoneal injections of Tocilizumab (an IL-6 receptor monoclonal antibody) not only mitigated BSCB breakdown but also alleviated pain behaviors. In addition, intervening β3-adrenoceptor (ADRB3) signaling in brown adipocytes by SR59230a (a specific ADRB3 antagonist) treatment or removal of brown adipose tissues could effectively decrease serum IL-6 levels, ameliorate BSCB disruption, and alleviate incisional pain. Further results displayed that SI-exposed rats also showed markedly spinal microglia activation. And exogenous His-tagged IL-6 could pass through the disrupted BSCB, which might contribute to microglia activation. Injection of SR59230a or ablation of brown adipose tissues could effectively reduce the activation of spinal microglia. Thus, our findings suggest that serum IL-6 induced by brown adipocyte ADRB3 signaling contributed to BSCB disruption and spinal microglia activation, which might be involved in preoperative stress mediated CPSP. This work indicates a promising treatment strategy for preoperative stress induced CPSP by blocking ADRB3.

Positive and negative emotion are associated with generalized transcriptional activation in immune cells

Alterations in immune system gene expression have been implicated in psychopathology, but it remains unclear whether similar associations occur for intraindividual variations in emotion. The present study examined whether positive emotion and negative emotion were related to expression of pro-inflammatory and antiviral genes in circulating leukocytes from a community sample of 90 adolescents (M_age = 16.3 years, SD = 0.7; 51.1% female). Adolescents reported their positive emotion and negative emotion and provided blood samples twice, five weeks apart. Using a multilevel analytic framework, we found that within-individual increases in positive emotion were associated with reduced expression of both pro-inflammatory and Type I interferon (IFN) response genes, even after adjusting for demographic and biological covariates, and for leukocyte subset abundance. By contrast, increases in negative emotion were related to higher expression of pro-inflammatory and Type I IFN genes. When tested in the same model, only associations with positive emotion emerged as significant, and increases in overall emotional valence were associated with both lower pro-inflammatory and antiviral gene expression. These results are distinct from the previously observed Conserved Transcriptional Response to Adversity (CTRA) gene regulation pattern characterized by reciprocal changes in pro-inflammatory and antiviral gene expression and may reflect alterations in generalized immunologic activation. These findings highlight one biological pathway by which emotion may potentially impact health and physiological function in the context of the immune system, and future studies can investigate whether fostering positive emotion may promote adolescent health through changes in the immune system.

Assessment of Anxiety in Surgical Patients: An Observational Study

Context:

Preoperative anxiety in surgical patients imposes stress and dissatisfaction. It results in altered neuroendocrine response and various perioperative complications.

Aims:

This study was conducted to determine the changes in anxiety level and need for information about the anesthetic and the surgical procedures at three different time points before surgery and evaluate the correlating factors.

Settings and Design:

A prospective observational study in a university hospital.

Materials and Methods:

Five hundred adults, American Society of Anesthesiologists Physical Status Class 1 and 2 patients were included in this study. Level of anxiety and need for information were assessed with the Amsterdam Preoperative Anxiety and Information Scale at three time points before the surgery: Evening before surgery in the ward (T₁); on the day of surgery, in the preoperative holding area (T₂); and in the operating room, after being positioned on the operating table (T₃). T-test was applied to compare the mean between two groups, and the Chi-square test for independence of association between two categorical variables. Mann–Whitney–Wilcoxon test was applied to test the equality of distribution between two groups. Kruskal–Wallis test was applied for one-way analysis for comparing median score, and Friedman test was applied for two-way analysis of comparing score among three time points.

Results:

Total anxiety score recorded was significantly different over the time period (P = 0.023), with an increasing trend over the time. Need for information did not change significantly over time period.

Conclusions:

Preoperative anxiety continues to increase from ward to operation table. The factors responsible are nonmodifiable.

Emodiversity and biomarkers of inflammation

There is growing evidence that inflammatory responses may help to explain how emotions get "under the skin" to influence disease susceptibility. Moving beyond examination of individuals' average level of emotion, this study examined how the breadth and relative abundance of emotions that individuals experience-emodiversity-is related to systemic inflammation. Using diary data from 175 adults aged 40 to 65 who provided end-of-day reports of their positive and negative emotions over 30 days, we found that greater diversity in day-to-day positive emotions was associated with lower circulating levels of inflammation (indicated by IL-6, CRP, fibrinogen), independent of mean levels of positive and negative emotions, body mass index, anti-inflammatory medications, medical conditions, personality, and demographics. No significant associations were observed between global or negative emodiversity and inflammation. These findings highlight the unique role daily positive emotions play in biological health. (PsycINFO Database Record

P-glycoprotein in autoimmune rheumatic diseases

P-glycoprotein (Pgp) is a transmembrane protein of 170 kD encoded by the multidrug resistance 1 (MDR-1) gene, localized on chromosome 7. More than 50 polymorphisms of the MDR-1 gene have been described; a subset of these has been shown to play a pathophysiological role in the development of inflammatory bowel disease, femoral head osteonecrosis induced by steroids, lung cancer and renal epithelial tumors. Polymorphisms that have a protective effect on the development of conditions such as Parkinson disease have also been identified. P-glycoprotein belongs to the adenosine triphosphate binding cassette transporter superfamily and its structure comprises a chain of approximately 1280 aminoacid residues with an N-C terminal structure, arranged as 2 homologous halves, each of which has 6 transmembrane segments, with a total of 12 segments with 2 cytoplasmic nucleotide binding domains. Many cytokines like interleukin 2 and tumor necrosis factor alpha increase Pgp expression and activity. Pgp functions as an efflux pump for a variety of toxins in order to protect particular organs and tissues as the central nervous system. Pgp transports a variety of substrates including glucocorticoids while other drugs such as tacrolimus and cyclosporine A act as modulators of this protein. The most widely used method to measure Pgp activity is flow cytometry using naturally fluorescent substrates such as anthracyclines or rhodamine 123. The study of drug resistance and its association to Pgp began with the study of resistance to chemotherapy in the treatment of cancer and antiretroviral therapy for human immunodeficiency virus; however, the role of Pgp in the treatment of systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis has been a focus of study lately and has emerged as an important mechanism by which treatment failure occurs. The present review analyzes the role of Pgp in these autoimmune diseases.

[Preoperative mood disorders in patients undergoing cardiac surgery: risk factors and postoperative morbidity in the intensive care unit]

INTRODUCTION AND OBJECTIVES

To estimate the preoperative levels of anxiety and depression in patients awaiting heart surgery and to identify the risk factors associated with the development of these mood disorders. To evaluate the relationship between preoperative anxiety and depression and postoperative morbidity.

METHODS

Prospective longitudinal study in a sample of 100 patients undergoing heart surgery. We carried out a preoperative structured interview in which the patient completed the Hospital Anxiety and Depression Scale, and sociodemographic (age, sex, marital status, and income) and surgical variables (surgical risk, type of surgery, length of preoperative hospital stay, and surgical history) were also recorded. Pain, analgesic use, and postoperative morbidity were evaluated in the intensive care unit.

RESULTS

Thirty-two percent of the patients developed preoperative anxiety and 19%, depression. Age < 65 years (odds ratio=3.05; 95% confidence interval, 1.27-7.3) was the only significant risk factor for developing preoperative anxiety. A length of preoperative hospital stay ≥ 3 days was the main risk factor for preoperative depression (odds ratio=4.59; 95% confidence interval, 1.6-13.17). Preoperative anxiety significantly increased the postoperative pain and analgesic consumption. Neither anxiety nor depression significantly modified the rest of the postoperative variables associated with morbidity in the intesive care unit.

CONCLUSIONS

Anxiety and depression are mood disorders that are detected in patients awaiting heart surgery, with age <65 years and a prolonged preoperative hospital stay being decisive factors in the development of these conditions. Although preoperative anxiety increased the postoperative pain in these patients, their state of mind did not modify their postoperative course.

Socioeconomic and psychosocial predictors of interleukin-6 in the MIDUS national sample

OBJECTIVE

To investigate whether psychosocial factors (i.e., depression, anxiety, and well-being) moderated educational gradients in interleukin-6 (IL-6) levels using data from the Survey of Midlife Development in the U.S. (MIDUS). The influences of educational attainment and psychosocial factors on IL-6 in middle aged and older adults were also examined.

DESIGN

Telephone interviews and mail surveys were utilized to collect educational attainment and psychosocial information from respondents (N = 1028). Respondents also participated in an overnight clinic visit, during which health information and a fasting blood sample were obtained.

MAIN OUTCOME MEASURES

Serum levels of IL-6.

RESULTS

Greater educational attainment predicted lower levels of IL-6 independent of age and gender, although this effect was attenuated after taking health behaviors, body mass index, waist-to-hip ratio, and chronic illnesses into account. Psychological well-being interacted with education to predict IL-6, such that for those with less education, higher well-being was associated with lower levels of IL-6.

CONCLUSION

The findings indicate a strong association between education and inflammation, which can be further moderated by psychosocial factors. The health benefits associated with psychological well-being were particularly evident for individuals with low educational attainment.

Pilot study of inflammatory responses following a negative imaginal focus in persons with chronic pain: analysis by sex/gender

BACKGROUND

Recent evidence suggests that differential stress and immune responses may play a role in the sex/gender disparity for pain. Pain pathology and psychological stress are both associated with elevated levels of proinflammatory cytokines.

OBJECTIVE

This pilot study tested a negative imaginal focus to assess whether it would elicit a proinflammatory cytokine response and whether responses would vary by sex/gender.

METHODS

Adults with chronic musculoskeletal pain were recruited from an outpatient, multidisciplinary pain clinic in Portland, Oregon, between 2007 and 2008. All participants underwent a psychologist-guided 10-minute focus on the negative aspects of their pain condition and the imagined worsening of their pain; no control group was used. Serum collected at baseline and postfocus (1, 2, and 2.5 hours) was assayed for interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Cortisol was assayed at each time point and at 15 minutes postfocus.

RESULTS

Thirty-six outpatients (aged 26-62 years; 23 women, 13 men) participated in the study. Compared with men, women displayed greater negative emotional expression during the experiment, and this in turn mediated their IL-6 inflammatory responses. Relative to men, the IL-6 response trajectory was delayed for women. The IL-6 and TNF-a findings suggest women's maximal cytokine responses were not captured by the final time point.

CONCLUSIONS

This pilot study provides preliminary evidence that women with chronic pain may experience increased and delayed inflammatory responses following negative emotional expression induced by thinking negatively about their pain condition. The findings have implications for pain catastrophizing research. This early-phase research suggests that the timing and duration of the cytokine response are critical factors to consider in future pain research.

A meta-analysis of cytokines in major depression

BACKGROUND

Major depression occurs in 4.4% to 20% of the general population. Studies suggest that major depression is accompanied by immune dysregulation and activation of the inflammatory response system (IRS). Our objective was to quantitatively summarize the data on concentrations of specific cytokines in patients diagnosed with a major depressive episode and controls.

METHODS

We performed a meta-analysis of studies measuring cytokine concentration in patients with major depression, with a database search of the English literature (to August 2009) and a manual search of references.

RESULTS

Twenty-four studies involving unstimulated measurements of cytokines in patients meeting DSM criteria for major depression were included in the meta-analysis; 13 for tumor necrosis factor (TNF)-alpha, 9 for interleukin (IL)-1beta, 16 for IL-6, 5 for IL-4, 5 for IL-2, 4 for IL-8, 6 for IL-10, and 4 for interferon (IFN)-gamma. There were significantly higher concentrations of TNF-alpha (p < .00001), weighted mean difference (WMD) (95% confidence interval) 3.97 pg/mL (2.24 to 5.71), in depressed subjects compared with control subjects (438 depressed/350 nondepressed). Also, IL-6 concentrations were significantly higher (p < .00001) in depressed subjects compared with control subjects (492 depressed/400 nondepressed) with an overall WMD of 1.78 pg/mL (1.23 to 2.33). There were no significant differences among depressed and nondepressed subjects for the other cytokines studied.

CONCLUSIONS

This meta-analysis reports significantly higher concentrations of the proinflammatory cytokines TNF-alpha and IL-6 in depressed subjects compared with control subjects. While both positive and negative results have been reported in individual studies, this meta-analytic result strengthens evidence that depression is accompanied by activation of the IRS.

Associations of depression with C-reactive protein, IL-1, and IL-6: a meta-analysis

OBJECTIVE

To assess the magnitude and direction of associations of depression with C-reactive protein (CRP), interleukin (IL)-1, and IL-6 in community and clinical samples.

METHODS

Systematic review of articles published between January 1967 and January 2008 in the PubMed and PsycINFO electronic databases was performed. Effect sizes were calculated as stat d and meta-analyzed, using random-effects models.

RESULTS

Each inflammatory marker was positively associated with depression; CRP, d = 0.15 (95% CI = 0.10, 0.21), p < .001; IL-6, d = 0.25 (95% CI = 0.18, 0.31), p < .001; IL-1, d = 0.35 (95% CI = 0.03, 0.67), p = .03; IL-1ra, d = 0.25 (95% CI = 0.04, 0.46), p = .02. Associations were strongest in clinically depressed patient samples--but were also significant in community-based samples--and when clinical interviews were used. Studies adjusting for body mass index (BMI) had smaller associations, albeit significant. Relationships were inconsistent with respect to age, medication, and sex. Depression was related to CRP and IL-6 among patients with cardiac disease or cancer.

CONCLUSIONS

Depression and CRP, IL-1, and IL-6 are positively associated in clinical and community samples and BMI is implicated as a mediating/moderating factor. Continuity in clinic- and community-based samples suggests there is a dose-response relationship between depression and these inflammatory markers, lending strength to the contention that the cardiac (or cancer) risk conferred by depression is not exclusive to patient populations. Available evidence is consistent with three causal pathways: depression to inflammation, inflammation to depression, and bidirectional relationships.

Association of catastrophizing with interleukin-6 responses to acute pain

Catastrophizing exerts its deleterious effects on pain via multiple pathways, and some researchers have reported that high levels of catastrophizing are associated with enhanced physiological reactivity to painful stimulation. In this project, 42 generally healthy adults underwent a series of psychophysical pain testing procedures assessing responses to noxious mechanical, heat, and cold stimuli. Pain catastrophizing cognitions were assessed prior to and then immediately after the various pain induction procedures. Blood samples were taken at baseline and then at several time points from the end of the procedures to 1h post-testing. Samples were assayed for serum levels of cortisol and interleukin-6 (IL-6). Both cortisol and IL-6 increased from baseline during the post-testing period (p's<.05), with cortisol returning to baseline by 1h post-testing and IL-6 remaining elevated. Pain catastrophizing, measured immediately after the pain procedures, was unrelated to cortisol reactivity, but was strongly related to IL-6 reactivity (p<.01), with higher levels of catastrophizing predicting greater IL-6 reactivity. In multivariate analyses, the relationship between catastrophizing and IL-6 reactivity was independent of pain ratings. Collectively, these findings suggest that cognitive and emotional responses during the experience of pain can shape pro-inflammatory immune system responses to noxious stimulation. This pathway may represent one important mechanism by which catastrophizing and other psychosocial factors shape the experience of both acute and chronic pain in a variety of settings.

Differential effects of faith-based coping on physical and mental fatigue in middle-aged and older cardiac patients

PURPOSE

This analysis investigated the effect of faith-based coping used by cardiac patients undergoing surgery on physical and mental fatigue, symptoms which have significant prognostic implications for mortality. Particularly, we explored whether this faith effect is independent or explained by positive mediators.

METHODS

Two weeks preoperatively, 481 patients (male, 58%; mean age = 62 years) were recruited for three sequential interviews. Among them, 426 completed the second interview, and 335 completed the post-operative follow-up. Cross-clamp and bypass time were obtained from patients' charts. Plasma interlukin-6 (IL-6) was used as a correlate of age-associated diseases and frailty.

RESULTS

Hierarchical multiple regression analyses showed that pre-operative positive religious coping styles and optimism contributed to reduced physical fatigue, controlling for post-operatively confirmed prayer coping and such covariates as severe injury. Depression and lower-back problems contributed to mental fatigue. No potential mediators explained these effects.

CONCLUSION

Faith-based coping and optimism are independent predictors of physical fatigue.