Low-Grade Inflammation and Ambulatory Cortisol in Adolescents: Interaction Between Interviewer-Rated Versus Self-Rated Acute Stress and Chronic Stress

Chronic early life stress alters the neuroimmune profile and functioning of the developing zebrafish gut

Chronic early life stress (ELS) potently impacts the developing central nervous and immune systems and is associated with the onset of gastrointestinal disease in humans. Though the gut-brain axis is appreciated to be a major target of the stress response, the underlying mechanisms linking ELS to gut dysfunction later in life is incompletely understood. Zebrafish are a powerful model validated for stress research and have emerged as an important tool in delineating neuroimmune mechanisms in the developing gut. Here, we developed a novel model of ELS and utilized a comparative transcriptomics approach to assess how chronic ELS modulated expression of neuroimmune genes in the developing gut and brain. Zebrafish exposed to ELS throughout larval development exhibited anxiety-like behavior and altered expression of neuroimmune genes in a time- and tissue-dependent manner. Further, the altered gut neuroimmune profile, which included increased expression of genes associated with neuronal modulation, correlated with a reduction in enteric neuronal density and delayed gut transit. Together, these findings provide insights into the mechanisms linking ELS with gastrointestinal dysfunction and highlight the zebrafish model organism as a valuable tool in uncovering how "the body keeps the score."

Work-related psychosocial factors and inflammatory markers: A systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to evaluate the prospective effect of adverse work-related psychosocial factors on increases in inflammatory markers.

METHODS

A systematic literature search was conducted in PubMed, Embase, PsycINFO, PsycARTICLES, and the Japan Medical Abstracts Society database. Studies were eligible for inclusion if they examined associations between work-related psychosocial factors and inflammatory markers (interleukin-6, tumor necrosis factor-alpha, and C-reactive protein), used longitudinal or prospective cohort designs, were conducted among workers, were original articles written in English or Japanese, and were published up to 2017 for the first search, October 2020 for the second, and November 2022 for the third. A meta-analysis was conducted using a random-effects model to assess the pooled effect size for the associations. A meta-regression analysis was used to estimate the association between length of follow-up and effect size. The ROBINS-I tool was used to assess risk of bias.

RESULTS

Of the 11,121 studies identified in the first search, 29,135 studies from the second, and 9448 studies from the third, eleven were eligible for this review and meta-analysis. The pooled coefficient between adverse work-related psychosocial factors and inflammatory markers was significant and positive (β = 0.014, 95% confidence interval: 0.005-0.023). However, a clear association was only observed for interleukin-6, and all the studies included had serious risks of bias. Meta-regression showed the effect size decreased depending on the follow-up period.

CONCLUSION

This study revealed a weak positive association between adverse work-related psychosocial factors and increases in inflammatory markers.

TRIAL REGISTRATION

PROSPERO CRD42018081553 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=81553).

Emotional Distress, Targeted Rejection, and Antibody Production After Influenza Vaccination in Adolescence

OBJECTIVE

The purpose of this study was to explore how both ongoing emotional distress and the experience of a targeted rejection over the past 6 months are associated with adolescents' antibody response to influenza virus vaccination. We predicted that experiencing a targeted rejection would amplify the hypothesized negative association between emotional distress and antibody response after vaccination.

METHODS

Adolescent participants (N = 148) completed two study visits (mean [standard deviation] days between visits = 27.4 [1.8]). At the first visit, they provided blood samples, were administered the seasonal (2018-2019) quadrivalent influenza vaccine (Fluzone, Sanofi Pasteur), completed questionnaires, and participated in a semistructured interview. At the second visit, they provided another blood sample. Hemagglutination-inhibition assays were conducted to determine prevaccination and postvaccination antibody titers. Targeted rejection experiences were coded from adolescents' interviews.

RESULTS

The emotional distress by targeted rejection interaction predicted antibody response to the two A strains and the composite of all vaccine strains (b values = -0.451 to -0.843, p values < .05), but not the two B strains. Results suggested that, among adolescents who experienced a targeted rejection over the past 6 months, emotional distress was negatively associated with vaccine response (however, this finding did not reach statistical significance). Conversely, among adolescents who did not experience a targeted rejection, emotional distress was positively associated with vaccine response (b = 0.173, p = .032).

CONCLUSIONS

The current study highlights the importance of evaluating both acute life events and ongoing distress as they relate to adaptive immune functioning in adolescence.

Therapeutic effect of Thymoquinone on behavioural response to UCMS and neuroinflammation in hippocampus and amygdala in BALB/c mice model

RATIONALE

Major depressive disorder is the leading cause of disability worldwide. The corticolimbic system plays a critical role in the emotional and cognitive aspects of major depressive disorder. Owing to the unsatisfactory efficacy of conventional antidepressants, there is a need to explore novel therapies.

OBJECTIVES

The current study aimed to explore the antidepressant potential of thymoquinone, a natural compound with anti-inflammatory activity, and propose its underlying mechanism of action in the unpredictable chronic mild stress (UCMS) mouse model.

METHODS

Coat state, forced swim test, elevated plus maze test, novelty suppressed feeding test and social interaction test were performed to quantify the behavioural shift induced by UCMS and the effect of thymoquinone and fluoxetine treatment. In addition, messenger RNA (mRNA) expression levels of inflammatory cytokines (IL-1β, IL-6 and TNF-α) and BDNF and NeuN were analysed by a quantitative real-time polymerase chain reaction in the hippocampus and amygdala of experimental and control groups.

RESULTS

UCMS significantly deteriorated coat state. Thymoquinone reinstated the resignation behaviour and latency to feed affected by UCMS. UCMS induced an increase in inflammatory cytokines (IL-1β, IL-6 and TNF-α) in the hippocampus and amygdala, which was decreased by thymoquinone. UCMS caused an increase in BDNF and NeuN mRNA levels in the amygdala while a decrease in the hippocampus. This opposite effect on BDNF was also compensated by thymoquinone; however, thymoquinone did not significantly change Ki67 and NeuN mRNA levels in the hippocampus.

CONCLUSIONS

Thymoquinone restored the behavioural changes induced by UCMS. In addition, the antidepressant effect of thymoquinone is in line with changes in inflammatory parameters and changes in BDNF in the hippocampus and amygdala.

Novel Insights From Interviewer Assessments of Personal Attributes, Home Environment, and Residential Context in NSHAP

OBJECTIVES

This study was aimed to describe the interviewer-assessed measures present in the 2015/2016 Round of National Social Life, Health, and Aging Project (NSHAP), outline strengths of interviewer-assessed measures, and explore how interviewer assessments in the domains of home environment and personal characteristics are associated with older adult health.

METHOD

Data come from the 2015/2016 Round of the NSHAP.

RESULTS

We provide descriptive results from the interviewer assessments of personal attributes, indoor home environment, and outdoor residential context. We present an illustrative analysis of reports of falls, a health outcome that might be predicted by characteristics assessed by the interviewer, and we suggest directions for further research.

DISCUSSION

Interviewer assessments collected in NSHAP are useful as proxy measures and can be used in combination with respondent's reports and ecological measures to generate insights into healthy aging.

Determinants of Chronic Biological Stress, Measured as Hair Cortisol Concentration, in a General Population of Adolescents: From Individual and Household Characteristics to Neighborhood Urbanicity

Chronic biological stress may adversely affect adolescents' physical and mental health, but insight in the personal and environmental factors that determine chronic stress is limited. We measured 3-month cumulative hair cortisol concentration (HCC) in 419 adolescents, participating in the Flemish Environment and Health Study. Adolescents' health and lifestyle characteristics, household and neighborhood socio-economic status as well as neighborhood urbanicity were assessed as potential determinants of HCC, using multiple linear regression models. We additionally explored heterogeneity of our results by sex. HCC were significantly higher in boys from densely populated neighborhoods, the association was not significant in girls. Accordingly, boys living outside cities had significantly lower HCC than boys, living in cities. HCC was significantly lower in adolescents with an optimal vitality, a measure of a positive mental health status. In adolescent girls, menarcheal status (pre-/postmenarche) was a significant determinant of HCC. Our findings are the first to suggest that residential urbanicity may have an impact on chronic biological stress in a general population of adolescent boys.

Annual Research Review: Social relationships and the immune system during development

A child's social relationships serve critical functions during development. The interface between a child's social world and their immune system, particularly innate immunity, which helped children survive in the face of infections, nutritional scarcity, and violence throughout human history, is the focus of this Annual Research Review. This article reviews the state of research on social relationships and innate immune inflammation during childhood. Warmth and rejection in childhood social relationships, as well as physical trauma and unpredictable social environments, were not consistently related to circulating inflammatory markers such as interleukin-6 and C-reactive protein during childhood. Instead, links between social environments and inflammation were observed in studies that focus on children with greater background risk factors, such as low family socioeconomic status, family history of mood disorders, or presence of chronic interpersonal stressors combined with acute episodic stressors. In addition, studies on worse childhood social environments and greater inflammation in adulthood were more consistent. Warmth and rejection in the social environment may be related to sensitivity of immune cells to the anti-inflammatory actions of glucocorticoids, though this is primarily observed in adolescent women at risk for depression. Additional mechanistic evidence suggests that greater warmth and less rejection are related to processes that regulate inflammation, including greater expression of the glucocorticoid receptor gene and lower expression of genes that are responsive to the pro-inflammatory transcription factor NF-kappa B. The article concludes by discussing implications of the interface between a child's social relationships and inflammation for mental health and other recent (on evolutionary timescales) health threats, as well as recommendations for future research, and recommendations for researchers interested in integrating inflammatory measures in developmental research.

The Relationship Between Disproportionate Social Support and Metabolic and Inflammatory Markers: Moderating Role of Socioeconomic Context

OBJECTIVE

The present study examines the association of disproportionate social support (the relative balance of support given versus received) on metabolic and inflammatory outcomes and whether effects vary by socioeconomic context.

METHODS

We enrolled a sample of 307 parental caregivers living with a child with a chronic illness. Parents were assessed on four dimensions of social support: emotional support received, instrumental support received, emotional support given, and instrumental support given. Disproportionate social support was calculated as the difference between support received and support given. Participants provided sociodemographic information, were interviewed about financial stress, and were assessed on metabolic (systolic blood pressure, diastolic blood pressure, total cholesterol, body fat percent, and body mass index) and inflammatory (interleukin 6 and C-reactive protein) outcomes.

RESULTS

More disproportionate instrumental and emotional support was associated with higher inflammation (b = 0.10, SE = 0.04, p = .014; b = 0.0.09, SE = 0.05, p = .042, respectively). We observed significant interactions between disproportionate social support and income (b = -0.04, SE = 0.02, p = .021). Parents from lower-income households who gave more emotional support than they received had higher inflammation compared with those from higher-income households. We also observed a significant interaction between disproportionate instrumental support and income (b = 0.04, SE = 0.02, p = .006). Parents from lower-income households who received more instrumental support than they gave had worse metabolic outcomes compared with parents from higher-income households. Parallel interaction patterns were observed using an interview-based measure of financial stress.

CONCLUSIONS

These findings show that disproportionate social support has implications for physical health, particularly for caregivers from socioeconomically disadvantaged households.

Immunoendocrine Markers of Stress in Seminal Plasma at IVF/ICSI Failure: a Preliminary Study

We have previously shown that high level of seminal interleukin (IL)-18 is positively associated with a greater risk of pregnancy failure in women exposed to their partners' seminal plasma (SP) during the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycle. Since IL-18 and IL-1β considered to be the key immune markers of stress, here we ask whether their increase in SP may be due to the stress experienced by men engaged in the IVF programs. Therefore, we correlated seminal IL-18 with IL-1β and both cytokines with the seminal steroids, whose increase indicates the activation of neuroendocrine stress response systems. Retrospective analysis of stored seminal samples was performed. Based on previously identified cutoff level for content of IL-18 per ejaculate, samples with high IL-18 content from IVF failure group (n = 9), as well as samples with low IL-18 content from IVF success group (n = 7), were included in the study. Seminal cytokines were evaluated using FlowCytomix™ technology. A set of 16 biologically active steroids in SP was quantified by liquid chromatography coupled with mass spectrometry. Concentrations and total amounts per ejaculate of cytokines and steroids were determined. A positive significant correlation was found between the levels of IL-18 and IL-1β. There was also a positive correlation between IL-18 or IL-1β and 17-α-hydroxypregnenolone, 17-α-hydroxyprogesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, progesterone, corticosterone, 11-deoxycorticosterone, and the ratio of DHEAS/cortisol. We suggested that stress-related overexpression of immune and hormonal factors in SP may be the key link between male stress and embryo implantation failure.

Mediating effects of hair cortisol on the mutual association of job burnout and insomnia: A retrospective exploratory study

BACKGROUNDS

The present study was designed to clarify the mutual association of job burnout and insomnia and to detect the mediating effects of hair cortisol on that association.

METHODS

In all, 68 female employees were recruited for the study from one secondary and one tertiary hospital between October 2018 and November 2018 in Beijing. Participants completed a questionnaire for the collection of demographic data and standardized measures for burnout and insomnia. Hair sample collection and anthropometric measurements were performed at the same time.

RESULTS

Median hair cortisol concentration (HCC) was 5.89 ng/g hair (interquartile range = 2.20-10.74). And ages are between 22 and 51 years old (32.50 ± 6.13), among which 22 were below 30 years, 20 were between 30 and 35 years, and 26 were over 35 years. A majority of Pearson's coefficients were significant, with the exception of that for the correlation between personal accomplishment and HCC or depersonalization. Significant mutual correlations were shown between burnout dimensions and insomnia directly. HCC acted as a mediator in the pathway from emotional exhaustion, depersonalization to insomnia; and no significant mediating effect of HCC in the pathway from insomnia to burnout was found.

CONCLUSIONS

Job burnout may directly or indirectly (through chronically elevated cortisol) increase insomnia risk, whereas insomnia probably promotes burnout. Prospective studies involving different body systems and a larger sample size should be performed to further identify the mechanisms underlying the associations between burnout and insomnia among the working population.

Inflammatory and vascular correlates of mood change over 8 weeks

Background

Mood disorders have been associated with a variety of cardiovascular disease risk factors, including inflammation and large artery stiffness, particularly while depressed although longitudinal studies have been limited.

Methods

With measurements at baseline and 8 weeks, the researchers prospectively assessed mood, levels of inflammatory markers (hsCRP and TNF-α), serum lipids, and large artery stiffness in a cohort of 26 participants with a diagnosis of a mood disorder, enriched for current depression. Depressive symptoms were measured using the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline and 8 weeks. Associations between depressive symptoms and other measures were assessed using linear mixed models, unadjusted and adjusted for age and BMI.

Results

The mean age of the participants (n=26) was 41.6 (standard deviation [SD] 12.8) years, and 81% were female. During the study, there was a mean (SD) MADRS score improvement of 9.5 (9.4) from baseline to eight weeks. Reductions in the primary outcome TNF-α with improvement in depression fell short of significance (P=0.076). In secondary analyses, there was a statistically significant association between improved cholesterol ratio (P=0.038) and triglycerides (P=0.042) with depression improvement. There was no statistically significant change in large artery stiffness during the study.

Conclusion

Improved depressive symptoms were associated with improved cholesterol ratios even after adjustment, suggesting possible mechanism by which acute mood states may influence cardiovascular disease risk. Future longitudinal studies with extended and intensive follow-up investigating cardiovascular disease risk related to acute changes and persistence of mood symptoms is warranted.

Associations of perceived stress with the present and subsequent cortisol levels in fingernails among medical students: a prospective pilot study

Purpose

Cortisol in fingernails could retrospectively reflect cumulative stress over a long period. However, the association between fingernail cortisol and perceived stress needs to be validated. This exploratory study aimed to investigate the associations of perceived stress with the present and subsequent cortisol levels in fingernails of the subjective stress measurement among medical students.

Methods

Students were recruited from a medical university in Shenyang, China. The final sample consisted of 51 students (16 men, 35 women). On the Day 30 of our data and fingernail collection procedure, the 10-item Perceived Stress Scale was used to measure perceived stress. Fingernail samples were collected twice, on Days 15 (denoted as FD15) and 45 (denoted as FD45) of the procedure, and participants were asked to grow fingernails for 15 days in each collection. Cortisol was determined by an enzyme immunoassay method using the ELISA kit. Multiple linear regression was performed to examine the association between perceived stress and cortisol level. The Bonferroni correction was made for multiple comparisons.

Results

The level of cortisol was 5.65 pg/mg (SD =1.88) for FD15 and 5.41 pg/mg (SD =1.63) for FD45. Perceived stress was not associated with the cortisol level of FD15 (β=−0.014, P=0.924), but it was significantly and positively associated with the cortisol level of FD45 (β=0.436, P=0.003), which remained significant after Bonferroni correction. The associations between fingernail cortisol and demographic variables (gender, age, BMI, and physical activity) were not significant.

Conclusion

This study was the first to investigate fingernail cortisol in China. Perceived stress was positively associated with the subsequent cortisol levels in fingernails, but not the present. The findings suggested that fingernail cortisol could indicate stress exposure in the past. Furthermore, a simple and easy self-reported measure could reflect cumulative stress as measured by fingernail cortisol.

Chronic Family Stress and Adolescent Health: The Moderating Role of Emotion Regulation

OBJECTIVE

The aim of the study was to assess whether the association between chronic family stress and physiological measures is moderated by emotion regulation strategies in an adolescent sample.

METHODS

Chronic family stress was assessed via a semistructured interview and emotion regulation strategies (cognitive reappraisal and suppression) via questionnaire among 261 adolescents (14.57 (1.07) years). Several metabolic (waist-hip ratio, systolic and diastolic blood pressure) and inflammatory markers (basal and stimulated proinflammatory cytokine production in response to bacterial challenge) as well as glucocorticoid sensitivity were assessed.

RESULTS

There were no main effects of chronic family stress, cognitive reappraisal, or suppression on physiological measures (all p's > .10). Emotion regulation moderated the association between chronic family stress and physiological measures. As chronic family stress increased, adolescents higher in cognitive reappraisal had smaller waist-hip ratios (B = -.003, SE = .001, p = .015) and lower systolic blood pressure (B = -.303, SE = .143, p = .035), although no moderation was found with respect to inflammatory markers and glucocorticoid sensitivity (all p's > .30). In addition, as chronic family stress increased, adolescents higher in suppression showed evidence of higher stimulated proinflammatory cytokine production (B = .046, SE = .020, p = .021) and lower glucocorticoid sensitivity (B = .051, SE = .021, p = .015), although basal inflammation and metabolic measures were not moderated by suppression (all p's > .50).

CONCLUSIONS

This study suggests that the types of emotion regulation strategies used by adolescents may affect the extent to which chronic family stress affects important metabolic and immune processes.