To assess, to control, to exclude: effects of biobehavioral factors on circulating inflammatory markers

Everyday co-presence with a romantic partner is associated with lower C-reactive protein

Social relationships are an important driver of health, and inflammation has been proposed as a key neurobiological mechanism to explain this effect. Behavioral researchers have focused on social relationship quality to further explain the association, yet recent research indicates that relationship quality may not be as robust a predictor as previously thought. Here, building on animal models of social bonds and recent theory on close relationships, we instead investigated merely being in the physical presence of one's romantic partner. Specifically, we tested the hypothesis that spending more time co-present with a loved partner in everyday life would be associated with lower C-reactive protein (CRP). Three times over the course of one month, 100 people in romantic relationships reported how much time they spent in the same physical space as their partner in the prior 24 h, in minutes, and provided a sample of blood for CRP assay (n observations = 296). Results from multi-level models showed that when one reported spending more time in the physical presence of their partner they had lower CRP - an effect that was independent from social relationship quality explanations from the prior literature, including romantic relationship quality, hostility, and loneliness. These findings move past global assessments of social isolation to consider a novel everyday behavior that is of great interest in the non-human animal literature - spending time together -- as a potential mechanism linking high-quality relationships and physical health in adult humans. The findings also point to future research on additional behavioral mechanisms that are not dependent on stress pathways: people in high-quality relationships tend to spend enjoyable and affectionate time with one another, which may impact inflammation.

Chronic Home Radon Exposure Is Associated with Higher Inflammatory Biomarker Concentrations in Children and Adolescents

Children are particularly vulnerable to the deleterious impacts of toxic environmental exposures, though the effects of some rather ubiquitous toxins have yet to be characterized in youths. One such toxin, radon gas, is known to accumulate to hazardous levels in homes, and has been linked with the incidence of lung cancer in aging adults. However, the degree to which chronic home radon exposure may impact risk for health problems earlier in life is unknown. Herein, we explored the degree to which chronic home radon exposure relates to biomarkers of low-grade inflammation in 68 youths ages 6- to 14 years old residing in an area of the United States prone to high home radon concentrations. Parents completed a home radon test kit, and youths provided a saliva sample to assess concentrations of five biomarkers. Using a multiple regression approach, we found that greater radon exposure was specifically associated with higher levels of C-reactive protein (β = 0.31, p = 0.007) and interleukin-1β (β = 0.33, p = 0.016). The data suggested specificity in associations between chronic home radon exposure and different biomarkers of inflammatory activity and highlight a pathway which may confer risk for future mental and physical health maladies.

Racial/ethnic variations in inflammatory markers: exploring the role of sleep duration and sleep efficiency

Individuals from minoritized racial/ethnic groups have higher levels of circulating inflammatory markers. However, the mechanisms underlying these differences remain understudied. The objective of this study was to examine racial/ethnic variations in multiple markers of inflammation and whether impaired sleep contributes to these racial/ethnic differences. Nurses from two regional hospitals in Texas (n = 377; 71.62% White; 6.90% Black; 11.14% Hispanic, 10.34% Asian; mean age = 39.46; 91.78% female) completed seven days of sleep diaries and actigraphy to assess mean and variability in total sleep time (TST) and sleep efficiency (SE). On day 7, blood was drawn to assess 4 inflammatory markers: C-reactive protein (CRP), Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α). Results from regression models showed differences in inflammatory markers by race/ethnicity, adjusting for age and gender. The associations between sleep parameters and inflammatory markers also varied by race/ethnicity. Among White nurses, lower mean and greater variability in actigraphy-determined TST and greater variability in diary-determined TST were associated with higher levels of IL-6. Among Black nurses, lower mean diary-determined SE was associated with higher levels of IL-6 and IL-1β. Among Hispanic nurses, greater diary-determined mean TST was associated with higher CRP. Among Asian nurses, greater intraindividual variability in actigraphy-determined SE was associated with lower CRP. Among nurses, we did not find racial/ethnic disparities in levels of inflammation. However, analyses revealed differential relationships between sleep and inflammatory markers by race/ethnicity. Results highlight the importance of using a within-group approach to understand predictors of inflammatory markers.

Pulmonary exacerbation inflammatory phenotypes in adults with cystic fibrosis

BACKGROUND

Adults with cystic fibrosis (CF) develop exuberant inflammatory responses during pulmonary exacerbations (PEx) but whether distinct systemic inflammatory profiles can be identified and whether these associate with disparate treatment outcomes are unclear. We conducted a pilot study to address this question and hypothesized that CF adults with a pauci-inflammatory phenotype might derive less clinical benefit from intravenous (IV) antibiotic treatment than patients with other systemic inflammatory phenotypes.

METHODS

Six proteins reflective of systemic inflammation were examined in 37 PEx from 28 unique CF subjects. We applied exploratory factor analysis and cluster analysis to identify biological clusters. Levels of blood proteins at PEx and clinical outcomes following IV antibiotic treatment were compared between clusters.

RESULTS

Three clusters of PEx were identified. The pauci-inflammatory phenotype was characterized by lower levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, calprotectin, and C-reactive protein (CRP) (p < 0.05). Higher levels of IL-6 and IL-1β were observed in the other 2 inflammatory clusters, but one of them was associated with higher calprotectin levels (p = 0.001) (neutrophil-predominant phenotype); whereas the other was associated with increased TNF-α and IL-10 levels (p < 0.001) (pro-inflammatory phenotype). A greater proportion of events from the neutrophil-predominant phenotype presented with acute respiratory symptoms and a larger decrease in ppFEV₁ from baseline to hospital admission than the other two inflammatory phenotypes (p = 0.03).

CONCLUSIONS

Three distinct inflammatory phenotypes were identified at PEx admission and each presented with unique clinical characteristics.

Validation of a novel method of ultraviolet-induced cutaneous inflammation and its associations with anhedonia

Affective immunology of the skin is a growing area; however, established protocols for measuring individual differences in cutaneous inflammation are lacking. To address this, we present a preliminary validation of Precision Implementation of Minimal Erythema Dose (PI-MED) testing as a method for measuring cutaneous inflammation. PI-MED is a recently adapted protocol, optimized for reproducibility and individual differences research, that uses ultraviolet (UV) light to evoke cutaneous erythema, or inflammatory skin reddening. PI-MED's novel UV dosage schedule produces standardized erythema responses across different skin pigmentation types and shows strong internal consistency within person and good test-retest reliability across 8-10 weeks. In line with predictions, increased PI-MED erythema was associated with heightened anhedonia, across several measures, beyond influences of non-affective covariates. While future work should further refine the dosage schedule for the lightest and darkest skin types, overall, evidence supports PI-MED as a protocol for inducing and measuring individual differences in cutaneous inflammation. Further, PI-MED-induced erythema can expand psychoneuroimmunology research by offering a complementary assessment for general inflammatory tone. This work adds to a growing body of evidence demonstrating a distinct relationship between inflammation and anhedonia.

Sleep disturbance and activation of cellular and transcriptional mechanisms of inflammation in older adults

BACKGROUND

Sleep disturbance, including poor subjective sleep quality and insomnia disorder, is common in older adults and associated with increases in age-related morbidity risk. Accumulating evidence implicates inflammation as an underlying mechanism. In two complementary studies, we examined whether sleep disturbance is associated with activation of cellular and transcriptional mechanisms of inflammation in older adults.

METHODS

Study 1 examined whether healthy older adults with poor subjective sleep quality (n = 62), compared to those with good subjective sleep quality (n = 101), differed in monocytic production of interleukin (IL)-6 and/or tumor necrosis factor (TNF)-α following stimulation with lipopolysaccharide. Study 2 examined whether older adults with insomnia disorder (n = 17), compared to those without insomnia disorder (n = 25), differed in the regulation of transcription factors (TFs) related to immune activation (i.e., nuclear factor-κB/Rel family), sympathetic nervous system (SNS) activity (i.e., cAMP-response element-binding protein), hypothalamic-pituitary-adrenal (HPA) axis activity (i.e., glucocorticoid receptor) and anti-viral responses (i.e., interferon-regulatory factor/interferon-stimulated response element) assessed in peripheral blood mononuclear cells.

RESULTS

In Study 1, older adults with poor subjective sleep quality, compared to those with good subjective sleep quality, showed higher percentages of stimulated monocytes producing IL-6 only (25.4 ± 16.8 % vs 20.4 ± 13.9 %; p < 0.05, η_p² = 0.03), producing TNF-α only (37.6 ± 13.1 % vs 31.2 ± 14.3 %; p < 0.01, η_p² = 0.05), and co-producing IL-6/TNF-α simultaneously (17.8 ± 11.7 % vs 13.9 ± 9.6 %; p < 0.05, η_p² = 0.03). In Study 2, older adults with insomnia disorder, compared to those without insomnia disorder, showed higher TF activity related to immune activation (p's < 0.05) and SNS function (p's < 0.001), along with lower TF activity related to HPA axis function (p's < 0.05).

CONCLUSION

In older adults, poor subjective sleep quality and insomnia diagnosis are associated with increases in monocytic cytokine production and changes in TF activity related to immune activation, SNS function, and HPA axis function. Activation of markers of cellular and transcriptional inflammation might contribute to the link between sleep disturbance and age-related morbidity risk.

Association between neutrophil to lymphocyte ratio and depression among US adults: From a large population-based cross-sectional study

OBJECTIVE

The study aims to determine the association between neutrophil to lymphocyte ratio (NLR) and depression and severity.

METHODS

We conducted a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES). The Patient Health Questionnaire (PHQ-9) was administered to assess depression and its severity. NLR was calculated as a neutrophil count-to-lymphocyte count ratio.

RESULTS

The study included 22,207 adults (mean age, 44.43 years; women, 51.05%), and 1671 (6.54%) reported depression. The association between NLR and depression was not significant (odds ratio [OR], 1.06, 95% confidence interval [CI], 0.98 to 1.15, p = 0.12) after fully adjusting the covariates, and similar results (Q1 reference Vs Q2: OR, 0.87, 95%CI, 0.70 to 1.07 Vs Q3: OR, 0.99, 95%CI, 0.80 to 1.21 Vs Q4: OR, 1.08, 95%CI, 0.86 to 1.35, p for trend 0.21) when NLR as a categorical variable. After controlling for all confounding variables, a U-shaped relationship between NLR and depression severity was observed, and the inflection point was 1.78. Subgroup analyses showed a significant association among Mexican American/other Hispanic (OR, 1.13, 95%CI, 1.00 to 1.28, p = 0.04), non-Hispanic blacks (OR, 1.18, 95%CI, 1.07 to 1.32, p = 0.002), the subjects with poverty income ratio above four (OR, 1.24, 95%CI, 1.00 to 1.53, p = 0.048) between NLR and depression. The results from the sensitivity analyses remained stable.

CONCLUSION

The association between NLR and depression is not general across depressed populations among US adults. This association may be specific to subgroups. The relationship between NLR and depression severity is non-linear.

Transdiagnostic inflammatory subgroups among psychiatric disorders and their relevance to role functioning: a nested case-control study of the ALSPAC cohort

Individuals with psychotic disorders and depressive disorder exhibit altered concentrations of peripheral inflammatory markers. It has been suggested that clinical trials of anti-inflammatory therapies for psychiatric disorders should stratify patients by their inflammatory profile. Hence, we investigated whether different subgroups of individuals exist across psychiatric disorders, based on their inflammatory biomarker signatures. We measured the plasma concentrations of 17 inflammatory markers and receptors in 380 participants with psychotic disorder, depressive disorder or generalised anxiety disorder and 399 controls without psychiatric symptoms from the ALSPAC cohort at age 24. We employed a semi-supervised clustering algorithm, which discriminates multiple clusters of psychiatric disorder cases from controls. The best fit was for a two-cluster model of participants with psychiatric disorders (Adjusted Rand Index (ARI) = 0.52 ± 0.01) based on the inflammatory markers. Permutation analysis indicated the stability of the clustering solution performed better than chance (ARI = 0.43 ± 0.11; p < 0.001), and the clusters explained the inflammatory marker data better than a Gaussian distribution (p = 0.021). Cluster 2 exhibited marked increases in sTNFR1/2, suPAR, sCD93 and sIL-2RA, compared to cluster 1. Participants in the cluster exhibiting higher inflammation were less likely to be in employment, education or training, indicating poorer role functioning. This study found evidence for a novel pattern of inflammatory markers specific to psychiatric disorders and strongly associated with a transdiagnostic measure of illness severity. sTNFR1/2, suPAR, sCD93 and sIL-2RA could be used to stratify clinical trials of anti-inflammatory therapies for psychiatric disorders.

Relationships Between Serum Cortisol, RAGE-Associated s100A8/A9 Levels, and Self-Reported Cancer-Related Distress in Women With Nonmetastatic Breast Cancer

OBJECTIVE

Elevated inflammation and psychological distress in patients with breast cancer (BCa) have been related to poorer health outcomes. Regulation of the hypothalamic-pituitary-adrenal axis and signaling of the receptor for advanced glycation end products (RAGE) are important in the inflammatory response and have been associated with increased stress and poorer health outcomes in patients with cancer. This study examined relationships among circulating cortisol, a measure of hypothalamic-pituitary-adrenal axis activity and physiological stress; s100A8/A9, a RAGE ligand and emerging cancer-related biological measure; and self-reported cancer-related distress.

METHODS

Patients with BCa ( N = 183, stages 0-IIIb) were recruited 2 to 10 weeks after surgery but before receiving adjuvant therapies. Participants provided blood samples, from which serum cortisol and s100A8/A9 levels were determined, and completed a psychosocial questionnaire. Regression analyses, adjusting for age, cancer stage, time since surgery, race, and menopausal status, were conducted examining the relationships between cortisol, s100A8/A9, and cancer-related distress (Impact of Event Scale [IES]-Revised).

RESULTS

Cortisol and s100A8/A9 levels were positively related ( β = 0.218, t (112) = 2.332, p = .021), although the overall model was not significant. Cortisol levels were also positively associated with IES-Intrusions ( β = 0.192, t (163) = 2.659, p = .009) and IES-Hyperarousal subscale scores ( β = 0.171, t (163) = 2.304, p = .022).

CONCLUSIONS

Patients with higher cortisol levels also reported higher s100A8/A9 levels and more cancer-related distress. The relationship between cortisol and s100A8/A9 supports a link between the stress response and proinflammatory physiological processes known to predict a greater metastatic risk in BCa. Stress processes implicated in cancer biology are complex, and replication and extension of these initial findings are important.

Peripheral blood inflammatory markers in depression: Response to electroconvulsive therapy and relationship with cognitive performance

The inflammatory response may play a role in depression and the response to antidepressants. Electroconvulsive therapy (ECT), the most acutely powerful antidepressant treatment, can also affect the innate immune system. Here, we determined circulating blood concentrations of the inflammatory mediators C-reactive protein (CRP), IL-1β, IL-6, IL-10, and TNF-α in depressed patients compared to healthy controls and assessed the effect of ECT on their concentrations. Relationships between inflammatory mediator concentrations and mood/cognition scores were also explored. Plasma CRP, IL-1β, IL-6, IL-10, and TNF-α concentrations were examined in 86 depressed patients and 57 controls. Relationships between inflammatory mediators and clinical or cognitive outcomes following ECT were assessed using correlation and linear regression analyzes, respectively. CRP, IL-6, IL-10, and TNF-α were elevated in patients at baseline/pre-ECT compared to controls. However, only IL-6 and TNF-α survived adjustment for potential confounders. IL-1β was undetectable in most samples. ECT did not significantly alter plasma concentrations of any of the inflammatory mediators. No relationship was identified between CRP, IL-6, IL-10, and TNF-α and mood or neurocognitive scores. Overall, our data do not support a major role for these four inflammatory markers in clinical outcomes following ECT or in cognition.

Sleep disruption induces activation of inflammation and heightens risk for infectious disease: Role of impairments in thermoregulation and elevated ambient temperature

Thermoregulation and sleep are tightly coordinated, with evidence that impairments in thermoregulation as well as increases in ambient temperature increase the risk of sleep disturbance. As a period of rest and low demand for metabolic resources, sleep functions to support host responses to prior immunological challenges. In addition by priming the innate immune response, sleep prepares the body for injury or infection which might occur the following day. However when sleep is disrupted, this phasic organization between nocturnal sleep and the immune system becomes misaligned, cellular and genomic markers of inflammation are activated, and increases of proinflammatory cytokines shift from the nighttime to the day. Moreover, when sleep disturbance is perpetuated due to thermal factors such as elevated ambient temperature, the beneficial crosstalk between sleep and immune system becomes further imbalanced. Elevations in proinflammatory cytokines have reciprocal effects and induce sleep fragmentation with decreases in sleep efficiency, decreases in deep sleep, and increases in rapid eye movement sleep, further fomenting inflammation and inflammatory disease risk. Under these conditions, sleep disturbance has additional potent effects to decrease adaptive immune response, impair vaccine responses, and increase vulnerability to infectious disease. Behavioral interventions effectively treat insomnia and reverse systemic and cellular inflammation. Further, insomnia treatment redirects the misaligned inflammatory- and adaptive immune transcriptional profiles with the potential to mitigate risk of inflammation-related cardiovascular, neurodegenerative, and mental health diseases, as well as susceptibility to infectious disease.

Adverse childhood experiences, bullying, inflammation and BMI in 10-year-old children: The biological embodiment

Exposure to adversity during the first years of life might already be biologically embedded well before adult life. Thus, the impact of different stressful experiences needs to be explored. This study aims to examine if the association between being victimized (adverse childhood experiences—ACEs and bullying) and (hs-) C-Reactive Protein (CRP) is explained by the influence of adversity on the body mass index (BMI) of the child. We included children from the Portuguese birth cohort Generation XXI (n = 3712) that at 10 years of age completed a questionnaire on the exposure to ACEs and bullying victimization, assessed by an adaptation from the original ACEs study and an adaptation of The Bully Scale Survey, respectively. Following an overnight fast, a venous blood sample was collected by trained nurses and hs-CRP was assayed in fresh blood samples. Weight and height were measured with the child in underwear and bare feet. Weight was measured to the nearest one-tenth of a kilogram with the use of a digital scale (Tanita), and height was measured to the nearest one-tenth of a centimetre with the use of a wall stadiometer (seca®). BMI was calculated as the value of weight (kg) over squared height (m), and computed as an age- and sex-specific BMI standard deviation (SD) score (z-score), according to the World Health Organization Child Growth Standards (5–19 years). Regression coefficients and respective 95% Confidence Interval [β(95%CI)] were computed using path analysis. We observed that ACEs had a positive total effect on hs-CRP at the age of 10 years (β = 0.06; 95%CI: -0.02; 0.15). A direct effect (β = 0.02; 95%CI: -0.01; 0.06) accounted for 66.1% of the association between ACEs and hs-CRP. A positive total effect of bullying victimization on hs-CRP (β = 0.20; 95%CI: 0.06; 0.34) was observed. A direct effect (β = 0.08; 95%CI: -0.05; 0.21) accounted for 40.0% of the association, while an indirect effect through BMI (β = 0.12; 95%CI: 0.06; 0.18) explained 60.0% of the pathway between bullying victimization and hs-CRP. Results suggest that there might be different mechanisms involved in the biological embedding of childhood experiences. BMI seems to explain a great part of the association between exposure to bullying victimization and hs-CRP at 10 years of age. Further research is still needed to better understand the mechanisms explaining the emergence and persistence of health poorer outcomes later in life for victims of abuse.

Acute health-related quality of life outcomes and systemic inflammatory markers following contemporary breast cancer surgery

Contemporary breast cancer surgical procedures vary greatly by the amount of tissue removed, anesthesia time, and reconstruction. Despite historical literature comparing the health-related quality of life (HRQOL) after lumpectomy and mastectomy, HRQOL data are limited regarding contemporary surgical procedures. Further, biological processes (e.g., inflammation) associated with HRQOL outcomes have not been described. We conducted two studies to examine differences in post-operative physical and mental functioning, pain, fatigue, and systemic inflammatory markers including interleukin (IL)-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP) in women with early-stage breast cancer. Study 1 assessed women before and after surgery (n = 27) and Study 2 used a large cross-sectional sample (n = 240) to confirm findings from Study 1 and included a no-surgery comparison group. In Study 1, women who received mastectomy had lower physical functioning than lumpectomy (ps < 0.05), and those who received bilateral mastectomy had worse pain (p < 0.01) and fatigue (p = 0.029) than lumpectomy. Results were replicated in Study 2: mastectomy groups exhibited poorer physical functioning (ps < 0.01) and greater pain (ps < 0.001) than lumpectomy, and bilateral mastectomy was associated with worse fatigue (p < 0.05). Women who received bilateral mastectomy had higher levels of CRP than lumpectomy (p < 0.01) and higher TNF-α than the no-surgery group (p < 0.05). All surgery groups exhibited higher IL-6 than no-surgery (ps < 0.05). More extensive surgery is associated with poorer postoperative HRQOL. As compared to lumpectomy and no-surgery, mastectomy is associated with higher concentrations of systemic inflammatory markers.

The role of the immune system in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) develops in a subset of individuals upon exposure to traumatic stress. In addition to well-defined psychological and behavioral symptoms, some individuals with PTSD also exhibit elevated concentrations of inflammatory markers, including C-reactive protein, interleukin-6, and tumor necrosis factor-α. Moreover, PTSD is often co-morbid with immune-related conditions, such as cardiometabolic and autoimmune disorders. Numerous factors, including lifetime trauma burden, biological sex, genetic background, metabolic conditions, and gut microbiota, may contribute to inflammation in PTSD. Importantly, inflammation can influence neural circuits and neurotransmitter signaling in regions of the brain relevant to fear, anxiety, and emotion regulation. Given the link between PTSD and the immune system, current studies are underway to evaluate the efficacy of anti-inflammatory treatments in those with PTSD. Understanding the complex interactions between PTSD and the immune system is essential for future discovery of diagnostic and therapeutic tools.

Could CRP be a differential biomarker of illness stages in schizophrenia? A systematic review and meta-analysis

BACKGROUND

Patients with schizophrenia display peripheral inflammation but the impact of illness phase is not clear. Our meta-analysis investigated the difference in CRP levels between patients with schizophrenia and controls according to their illness phase.

METHODS

After a systematic search, all studies measuring CRP in patients with schizophrenia and controls were included. Standardized mean differences were calculated between patients and controls according to illness phase. The influence of sociodemographic and clinical variables on our results was investigated using a meta-regression analysis.

RESULTS

Fifty studies were included in this meta-analysis. Patients with schizophrenia had higher CRP levels than controls in the acute (p < 0.00001) and stable (p < 0.00001) stage of their disease. Patients with acute exacerbation of schizophrenia had higher CRP levels than stable patients (p = 0.02) but this difference did not persist when considering antipsychotic-medicated patients in both phases. Meta-regressions found that the increase of CRP in acutely ill patients as compared to controls was influenced by age (p < 0.01), BMI (p = 0.01) and first episode (p = 0.02), whereas the increase in CRP levels of stable patients as compared to controls was moderated by BMI (p = 0.004).

CONCLUSIONS

In conclusion, this meta-analysis provides strong evidence that patients with schizophrenia have higher CRP levels than controls, but also show an increase in inflammatory response in the acute stage of the disease as compared to the stable stage. CRP could thus be considered as a state marker and a trait marker of the disease.

Does the moderator matter? Identification of multiple moderators of the association between peripheral inflammatory markers and depression severity in a large racially diverse community cohort

Depressive symptomology has been linked to low-grade peripheral inflammatory markers (PIMs), specifically C-reactive protein (CRP) and white blood cell count (WBC). However, such associations may be affected by multiple moderators (including race/ethnicity), though few well-powered and racially diverse studies have examined this. We examined 31 moderators of PIM-depression relationships in a large racially diverse cohort (n = 21,570). We also examined if associations between PIM and depression severity were dependent on clinical cutpoints for moderate depressive symptoms and elevated CRP. We found several positive moderators of PIM-depression relationships for both WBC and CRP: ongoing medication use (antidepressant, statin, or any prescription drug), presence of sleep concerns, and poor health status (β's = 0.06-0.21, p's < 0.05). For both WBC and CRP, individuals of non-Hispanic White race/ethnicity were found to have stronger PIM-depression associations overall relative to minoritized groups (B's = 0.14 to 1.01, p's < 0.05). For CRP, stronger PIM-depression relationships existed for individuals with moderate (or greater) depression severity or elevated CRP (B's = 0.27 to 0.49, p's < 0.05). Thus, a wide range of moderators appears to affect PIM-depression associations. These results could help identify participants with strong coupling of PIM-depression severity, to guide future research and personalized treatments for depression and to indicate gaps in the applicability of widely referenced theoretical models among racial/ethnic minoritized groups.

Psychosocial Resilience to Inflammation-Associated Depression: A Prospective Study of Breast-Cancer Survivors

Stress can lead to depression, in part because of activation of inflammatory mechanisms. It is therefore critical to identify resilience factors that can buffer against these effects, but no research to date has evaluated whether psychosocial resilience mitigates the effects of stress on inflammation-associated depressive symptoms. We therefore examined psychosocial resources known to buffer against stress in a longitudinal study of women with breast cancer (N = 187). Depressive symptoms and inflammation were measured over a 2-year period extending from after diagnosis into survivorship. Cancer-related stress and psychosocial resources-social support, optimism, positive affect, mastery, self-esteem, and mindfulness-were measured after diagnosis. As hypothesized, women who reported having more psychosocial resources showed weaker associations between stress and depressive symptoms and weaker associations between stress and inflammation-related depressive symptoms. Results highlight the importance of psychosocial resilience by demonstrating a relationship between psychosocial resources and sensitivity to inflammation-associated depressive symptoms.

Student Debt and Cardiovascular Disease Risk Among U.S. Adults in Early Mid-Life

INTRODUCTION

Student loan debt has become common for young adults in the U.S. and is correlated with poor physical and mental health. It is unclear how the accumulation or repayment of student debt is associated with longer-term cardiovascular risks and chronic inflammation.

METHODS

Nationally representative data collected between 1994 and 2018 from >4,000 participants of a U.S. cohort study were analyzed in 2021 to assess the associations among change in student debt between young adulthood and early mid-life, 30-year Framingham cardiovascular disease risk scores, and C-reactive protein levels.

RESULTS

Ordinary least squares regression revealed higher cardiovascular disease and C-reactive protein risks among those in households who became indebted or were consistently in debt between young adulthood and early mid-life than among those in households who were either never in debt or repaid their loans. This pattern persisted after adjustments for degree completion, socioeconomic measures, and other sources of debt.

CONCLUSIONS

These findings provide a benchmark for widening health inequalities among a cohort bearing more student debt than any other in U.S.

HISTORY

As student debt accumulates, within-cohort disparities in cardiovascular disease and related morbidities may undermine the health benefits of postsecondary education.

Neural and peripheral markers of reward during positive social evaluation are associated with less clinician-rated depression symptom severity in adolescence

Although blunted sensitivity to reward is thought to play a key role in promoting risk for depression, most research on this topic has utilized monetary reward paradigms and focused on currently depressed adults. To address this issue, we analyzed neural reward and β-endorphin data from the Psychobiology of Stress and Adolescent Depression (PSY SAD) Study, which recruited a well-characterized sample of adolescent girls at high vs. low risk for major depressive disorder (MDD) (N = 52, M age = 14.90, SD = 1.35) based on their mothers' lifetime history of MDD. As hypothesized, greater striatal activity while receiving positive (vs. neutral) social evaluation was associated with lower depression symptom severity as independently assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS). This association was present for girls at high but not low risk for MDD, suggesting that this neural response may represent a pre-clinical marker of risk for depression. Consistent with these results, higher post-social evaluation levels of a peripheral marker of reward sensitivity, β-endorphin, were related to lower clinician-rated depression symptom severity. Together, these results indicate that neural and peripheral markers of responsivity to social reward are both related to depression severity, which may have implications for understanding the pathophysiology of depression.

Psychological well‐being and salivary markers of inflammation: The moderating effect of age

Increasing evidence suggests a significant impact of higher psychological well-being (PWB) on health outcomes; however, such associations have been studied exclusively in middle-aged to older adults. This study examined the aging effect on PWB measures as well as the moderating effect of age on the link between PWB and inflammation, using salivary markers by comparing the younger adults (n = 127; M_age  = 22.98 years) versus older adults (n = 75; M_age  = 75.60 years). Older adults showed significantly lower levels of PWB, particularly regarding purpose in life and personal growth. Moreover, higher purpose in life was associated with lower salivary IL-1ß and IL-6 (b = 0.83, p < .001; b = 0.81, p < .01) only in the older adult group but not in younger adults. These findings highlight the potential buffering effect of the sense of living well on physiological pathways in later life.

An evidence review of the association of immune and inflammatory markers with obesity-related eating behaviors

Background

Eating behaviors contribute to disproportionate energy intake and are linked to the development of obesity. Animal studies support the role of inflammatory cytokines and chemokines in the regulation of obesity-related eating behaviors and offer a potential target to combat obesity through the modulation of inflammation. However, more complex eating behaviors are present in humans, and their relationships with immune/inflammation markers are unclear. The present study reviewed current literature to synthesize the evidence on the association of immune/inflammation markers with obesity-related eating behaviors in humans.

Methods

A systematic search of three electronic databases yielded 811 articles, of which 11 met the inclusion criteria.

Results

The majority of the included studies (91%) were either case-control or cross-sectional studies. A variety of immune/inflammation markers and obesity-related eating behaviors have been assessed in the chosen studies. Three out of four studies identified a positive relationship between C-reactive protein (CRP)/high-sensitivity CRP and loss of control eating. Other inflammatory markers that potentially have a positive relationship with obesity-related eating behaviors include fractalkine and fibrinogen. Additionally, immune molecules, including interferon gamma (INF-γ), interleukin (IL)-7, IL-10, and α-melanocyte-stimulating hormone-reactive immunoglobulin G (α-MSH/IgG) immune complex, may have negative associations with obesity-related eating behaviors. However, most findings were identified by single studies.

Conclusion

Limited studies have been conducted in humans. Current evidence indicates a potential bi-directional relationship between inflammatory/immune markers and obesity-related eating behaviors. Additional studies with sophisticated research design and comprehensive theoretical models are warranted to further delineate the relationship between immune/inflammation markers and obesity-related eating behaviors.

Psychiatric symptoms are not associated with circulating CRP concentrations after controlling for medical, social, and demographic factors

Elevated serum concentrations (>3 mg/L) of the acute-phase protein, C-reactive protein (CRP), is used as a clinical marker of inflammation and is reported to be a strong risk factor for cardiovascular disease. In psychiatric populations, CRP concentration is reported to be higher in depressed versus healthy individuals. Positive associations between CRP and depression have been established in both clinical and community samples, but effect sizes are attenuated after controlling for confounding variables. Similarly, emerging research has begun to draw a link between inflammation, symptoms of anxiety, and substance abuse. Given the high level of comorbid anxiety and substance use disorders in many depressed populations, this study examined whether depression (Patient Health Questionnaire 9 [PHQ-9]) and substance use-related (Drug Abuse Screening Test [DAST]) symptoms were associated with CRP concentrations in the blood after adjusting for relevant medical, social, and demographic covariates in a large sample undergoing screening for several transdiagnostic psychiatric research studies. A total of 1,724 participants were analyzed for association of CRP with variables using multivariate linear regression. An unadjusted model with no covariates showed that PHQ-9 was significantly associated with CRP in All (β = 0.125), Female (β = 0.091), and Male (β = 0.154) participants, but DAST was significantly associated with CRP in males only (β = 0.120). For the adjusted model, in both males and females, mood-stabilizer treatment (β = 0.630), opioid medication (β = 0.360), body mass index (β = 0.244), percent body fat (β = 0.289), nicotine use (β = 0.063), and self-reported sleep disturbance (β = 0.061) were significantly associated with increased CRP concentrations. In females, oral contraceptive use (β = 0.576), and waist-to-hip ratio (β = 0.086), and in males, non-steroidal anti-inflammatory drug use (β = 0.367) were also associated with increased CRP concentrations. There was no significant association between CRP and individual depressive, anxiety, or substance use-related symptoms when covariates were included in the regression models. These results suggest that associations between circulating CRP and the severity of psychiatric symptoms are dependent on the type of covariates controlled for in statistical analyses.

Sense of purpose in life and inflammation in healthy older adults: A longitudinal study

BACKGROUND

A higher sense of purpose in life has been linked with reduced risk of age-related chronic health conditions that share elevated inflammation as a key risk factor (e.g., neurodegenerative diseases, heart disease, and diabetes). While prior research has documented cross-sectional associations between higher sense of purpose and lower inflammation, few studies have examined the association between purpose and changes in inflammation over time.

OBJECTIVE

We tested if a higher sense of purpose was prospectively associated with lower likelihood of developing unhealthy C-reactive protein levels in older adults who initially had healthy CRP levels (i.e., <3 ug/mL).

METHODS

Participants were 6925 adults aged > 50 in the Health and Retirement Study who were followed for 8 years. Participants completed the purpose in life subscale of the Ryff Psychological Well-being Scales at study baseline in 2006/2008. CRP was obtained from blood spots collected at baseline and after 4 and 8 years of follow-up. Pooled logistic regression estimated discrete-time hazard ratios (HR) and 95% confidence intervals (CI) for the association between baseline purpose and onset of unhealthy CRP levels (>3 ug/mL).

RESULTS

There was no strong evidence of an association between baseline continuous purpose scores and onset of unhealthy CRP levels over time in the overall analytic sample. In sex-stratified models, higher purpose was associated with lower hazards of developing unhealthy CRP levels among men, while associations were null in women (e.g., in sociodemographics-adjusted model, men: HR=0.89, 95% CI: 0.79-0.99; women: HR=0.96, 95% CI: 0.85-1.08; interaction between continuous purpose scores and sex p = 0.15).

CONCLUSIONS

Findings suggest that a higher versus lower sense of purpose is associated with lower inflammation levels in older men. In specific populations, purpose may serve as a novel target for future interventions aimed at reducing inflammation.

Residence in High-Crime Neighborhoods Moderates the Association Between Interleukin 6 and Social and Nonsocial Reward Brain Responses

BACKGROUND

Residence in high-crime neighborhoods, especially in childhood, is linked to mental health issues later. Detecting distinct neurobiological processes underlying the effects of this environmental stressor may be critical to identifying prevention and intervention targets. This study examined the relationships of levels of a circulating inflammatory protein with social and monetary reward-related brain function among adolescents who lived in high- versus low-crime neighborhoods during childhood.

METHODS

A total of 70 participants (mean age = 16.3 years; 57% female) completed measures of inflammatory markers, depression history, and health and 2 functional magnetic resonance imaging tasks assessing responsivity to monetary and social rewards. Multivariate linear regression tested whether individuals with higher interleukin 6, an inflammatory cytokine, who also lived in neighborhoods with higher crime had distinct orbitofrontal cortex and nucleus accumbens activation to monetary reward and social acceptance.

RESULTS

For adolescents who lived in neighborhoods with more crime, higher interleukin 6 was associated with higher nucleus accumbens responses to social acceptance. We did not detect significant moderating effects of neighborhood crime rates on the associations of interleukin 6 with orbitofrontal cortex responses to social acceptance or orbitofrontal cortex/nucleus accumbens activation during monetary reward anticipation or outcome. These results were obtained before and after adjusting for neighborhood income and other covariates. We did not detect significant moderating effects of neighborhood income.

CONCLUSIONS

High-threat residence environment and specific demands of the social context in childhood may have shaped the effect of peripheral immune activation on reward-related neural function in adolescence. The prevailing view that inflammation-associated behaviors are characterized by blunted responsiveness to reward may be oversimplistic.

Women with lower systemic inflammation demonstrate steeper cognitive decline with age: Results from a large prospective, longitudinal sample

Background

Men and women experience large disparities in prevalence, detection, and clinical course of neurodegenerative diseases. Inflammation has been implicated in the pathogenesis of neurodegenerative diseases, yet there is a paucity of literature documenting sex differences in this phenomenon in prospective, longitudinal studies.

Methods

Participants were 4217 non-smoking individuals (62.2% female; aged 46–91 at enrollment) enrolled in the Health and Retirement Study who provided dried blood spots and completed a standardized assessment of cognitive function 3 times across 8 years. Inflammation was indexed using C-reactive protein (CRP).

Results

Higher CRP was associated with lower concurrent cognitive function, b = −0.13 (SE = 0.06), p < .05, but less decline in cognitive function over time, b = 0.02 (SE = 0.01), p < .05. Sex moderated the association between CRP and decline in total cognitive function, b = 0.02 (SE = 0.01), p < .05, such that the steepest declines in cognitive function were observed among women with the lowest CRP concentrations.

Conclusions

Women with lower systemic inflammation as measured by CRP may be at risk of going undetected for neurodegenerative disease, especially given their overall higher cognitive scores. This may perpetuate sex-related disparities in prevention and clinical course. Attention to the underlying biological mechanisms explaining the link between lower CRP and risk for cognitive decline for women and its potential clinical implications are needed.

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Sex differences in links between inflammation and cognitive function are under-explored.

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Higher CRP was associated with lower concurrent cognitive function, only in men.

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Women with lower CRP showed the steepest declines in cognitive functioning.

Grief Symptoms Promote Inflammation During Acute Stress Among Bereaved Spouses

The death of a spouse is associated with maladaptive immune alterations; grief severity may exacerbate this link. We investigated whether high grief symptoms were associated with an amplified inflammatory response to subsequent stress among 111 recently bereaved older adults. Participants completed a standardized psychological stressor and underwent a blood draw before, 45 min after, and 2 hr after the stressor. Those experiencing high grief symptoms (i.e., scoring > 25 on the Inventory of Complicated Grief) experienced a 45% increase in interleukin-6 (IL-6; a proinflammatory cytokine) per hour, whereas those experiencing low grief symptoms demonstrated a 26% increase. In other words, high grief was related to a 19% increase in IL-6 per hour relative to low grief. The grief levels of recently bereaved people were associated with the rate of change in IL-6 following a subsequent stressor, above and beyond depressive symptoms. This is the first study to demonstrate that high grief symptoms promote inflammation following acute stress.

Individuals with both higher recent negative affect and physical pain have higher levels of C-reactive protein

Conceptualizing physical pain and negative affect as potentially interactive, we hypothesized that higher levels of peripheral inflammatory markers would be observed consistently only among individuals with both higher negative affect and pain symptomatology. Participants were generally healthy midlife adults from the Bronx, NY (N ​= ​212, M_age ​= ​46.77; 60.8% Black, 25.5% Hispanic/Latina/o) recruited as part of a larger study. Key measures were: reported pain intensity and pain interference at baseline, recent negative affect averaged from self-reports 5x/day for 7 days, and peripheral inflammatory markers (C-reactive protein [CRP] and a composite cytokine measure based on seven cytokines). Controlling for age, BMI, gender, and education, recent negative affect significantly interacted with both pain variables to explain variance in CRP, with higher CRP levels observed only in individuals with both higher negative affect and either higher pain intensity or pain interference. These findings contribute to an emerging literature suggesting that negative affect, pain, and inflammation are related in important and complex ways.

Associations of three major physiological stress systems with suicidal ideation and suicide attempts in patients with a depressive and/or anxiety disorder

BACKGROUND

People with depressive and/or anxiety disorders are at increased risk of suicidal ideation and suicide attempts, but biological correlates signaling such risk remain unclear. Independent and cumulative dysregulations in physiological stress systems, in particular the hypothalamic-pituitaryadrenal axis (HPA-axis), immune-inflammatory system, and autonomous nervous system (ANS), may contribute to this risk. However, findings have either been heterogeneous or absent thus far.

METHODS

Associations between individual markers and cumulative indices of the HPA-axis (cortisol awakening response and evening cortisol), immune-inflammatory system (C-reactive protein, interleukin-6 (IL-6), and tumor necrosis factor-α), and the ANS (heart rate, respiratory sinus arrhythmia, and pre-ejection period) and the outcomes no suicide ideation with suicide attempt (SI-SA+), suicide ideation without suicide attempt (SI+SA-) and suicide ideation with suicide attempt (SI+SA+) were investigated in 1749 persons with depressive and/or anxiety disorders from the Netherlands Study of Depression and Anxiety (NESDA).

RESULTS

High levels of CRP and IL-6 were associated with SI-SA+ and SI+SA+ respectively when compared to non-suicidal patients after adjusting for confounders and multiple testing. Also, cumulative immune-inflammatory dysregulations were positively associated with SI+SA+, suggesting a dose-response effect. No significant associations were found between HPA-axis or ANS indicators and suicide-outcomes and between immune-inflammatory system markers or cumulative stress system dysregulations and SI+SA-.

CONCLUSION

Although stress system markers could not differentiate between SI+SA- and non-suicidal patients, findings indicate that dysregulations of individual and cumulative immune-inflammatory markers are associated with suicide attempts in depressive and/or anxiety patients. Thus, immune-inflammatory system dysregulation may be involved in the pathophysiology of suicidal behavior, supporting further examination of the effects of anti-inflammatory interventions on suicidality.

Sleep duration trajectories associated with levels of specific serum cytokines at age 5: A longitudinal study in preschoolers from the EDEN birth cohort

Sleep is essential for optimal child development and health during the life course. However, sleep disturbances are common in early childhood and increase the risk of cognitive, metabolic and inflammatory disorders throughout life. Sleep and immunity are mutually linked, and cytokines secreted by immune cells could mediate this interaction. The sleep modulation of cytokines has been studied mostly in adults and adolescents; few studies have focused on school-aged children and none on preschoolers. We hypothesized that night sleep duration affects cytokine levels in preschoolers. In a sample of 687 children from the EDEN French birth cohort, we studied the associations between night sleep duration trajectories from age to 2–5 years old and serum concentrations of four cytokines (Tumor necrosis factor α [TNF-α], Interleukin 6 [IL-6], IL-10, Interferon γ [IFN)-γ] at age 5, adjusting for relevant covariates. As compared with the reference trajectory (≈11h30/night sleep, 37.4% of children), a shorter sleep duration trajectory (<10 ​h/night, 4.5% of children), and changing sleep duration trajectory (≥11h30/night then 10h30/night, 5.6% of children) were associated with higher serum levels of IL-6 and TNF-α, respectively at age 5. We found no associations between sleep duration trajectories and IL-10 or IFN-γ levels. This first longitudinal study among children aged 2–5 years old suggests an impact of sleep duration on immune activity in early childhood. Our study warrants replication studies in larger cohorts to further explore whether and how immune activity interacts with sleep trajectories to enhance susceptibility to adverse health conditions.

Low social and family well-being is associated with greater RAGE ligand s100A8/A9 and interleukin-1 beta levels in metastatic breast cancer patients

Greater inflammatory signaling has been shown to promote breast cancer disease progression and poorer clinical outcomes. Lower social support and social well-being have been related to greater inflammatory signaling and poorer clinical outcomes in women with non-metastatic breast cancer, and this appears to be independent of depression. However, little is known about these associations in women with metastatic disease. s100A8/A9 and interleukin 1 beta (IL-1β) proteins are widely studied in breast cancer and are considered as biomarkers of cancer progression or as having a causal role in carcinogenesis and cancer progression and metastasis via inflammatory signaling. The aim of this study was to examine the associations between less social/family well-being (SWB) and S100A8/A9 and IL-1β levels in women diagnosed with metastatic breast cancer. Sixty women (Mean age 58.95 ​± ​1.49) with a diagnosis of metastatic breast cancer participated in the study. The Functional Assessment of Cancer Therapy (FACT) social and family well-being (SWB) subscale and the Hospital Anxiety Depression Scale (HADS) were administered to patients undergoing a first- or second-line endocrine or oral chemotherapy treatment and who were not experiencing brain metastasis or visceral crisis. Salivary s100A8/A9 and IL-1β levels were assessed at 5PM on two consecutive days and averaged. Multiple regression tested the independent contribution of SWB on s100 A8/A9 and IL-1b while controlling for depression. Lower levels of SWB were associated with greater S100A8/A9 (ß ​= ​-0.345, p ​= ​0.007) and IL-1β (ß ​= ​-0.286, p ​= ​0.027) levels and these associations remained significant after controlling for depression. This work provides new evidence for the role of decreased SWB and greater s100A8/A9 and IL-1b levels in patients diagnosed with metastatic breast cancer. Psychosocial interventions that promote social support and positive social interactions through interpersonal skills may help metastatic breast cancer patients to improve their SWB. This may have salutary effects on cancer-promoting processes, which could provide psychological and physical health benefits.

First-generation College Students Have Greater Systemic Inflammation than Continuing-Generation College Students Following the Initial College Transition: A Brief Report

BACKGROUND

First-generation college students ("first-gens") are often at a disadvantage socially and academically; whether they are at risk physiologically is unknown despite the well-established link between greater education and better long-term health.

PURPOSE

To examine whether first-gens have higher levels of cardiovascular disease (CVD) risk markers relative to continuing-generation college students ("continuing-gens").

METHODS

A panel of CVD risk markers was assessed among 87 emerging adults (41 first-gens) twice over their first year of college.

RESULTS

Compared to continuing-gens, first-gens had greater systemic inflammation (composite of averaged z-scores for C-reactive protein and interleukin-6; B = 0.515, SE = 0.171, p = .003) during the fall but not spring semester (p > .05). Associations were independent of family home ownership and childhood adversity, even though first-gens were more likely to live in rental homes and reported riskier home environments. Lower childhood subjective social status (SSS) accounted for greater systemic inflammation among first-gens as evidenced by an indirect effect of college generation status on systemic inflammation through childhood SSS (a1b1 = 0.261, bootstrapped SE = 0.103, 95% boot CI [0.078, 0.482]). There were no differences in metabolic risk and latent virus regulation by college generation status in either semester (p > .10).

CONCLUSIONS

This is the first study to find that first-gens have higher levels of systemic inflammation than continuing-gens following the college transition and that childhood SSS may be one explanatory pathway. First-gens may benefit from university resources that address social class differences, which should be provided early on so that first-gens can reap the health-relevant benefits of higher education, at least in the short term.

Early-life stress, depressive symptoms, and inflammation: the role of social factors

OBJECTIVE

To identify modifiable, social factors that moderate the relationship between early-life stress (ELS) and health outcomes as measured by depressive symptoms and inflammation.

METHODS

Data were from 3,416 adults (58.28% female), ages 36 - 97 (M_age = 68.41; SD_age = 10.24) who participated in the 2006 wave of the Health and Retirement Study, a nationally representative sample of older adults in the United States. This study used hierarchical regression analyses to first test the main effects of ELS on depressive symptoms and inflammation (high-sensitivity C-reactive protein). Four social factors (perceived support, frequency of social contact, network size, and volunteer activity) were assessed as moderators of the ELS-depression and ELS-inflammation relationships.

RESULTS

There was a small, positive association between ELS and depressive symptoms (B = 0.17, SE = 0.05, p = .002), which was moderated by social contact and perceived support. Specifically, ELS was only associated with elevated depressive symptoms for participants with limited social contact (B = 0.24, SE = 0.07, p < .001) and low perceived support (B = 0.24, SE = 0.07, p < .001). These associations remained after accounting for potential confounds (age, body-mass index, adulthood stress, and marital status).

CONCLUSIONS

Increased social contact and perceived support may be protective for individuals at a higher risk of developing depressive symptoms as a result of ELS. Future interventions may benefit from leveraging these social factors to improve quality of life in adults with ELS.

Immunological and psychosocial functioning in parents of children with cancer

PURPOSE

Research has shown that parents of children with cancer exhibit an altered immune profile compared to parents of healthy children, reflective of increased susceptibility to illness. These parents are also at risk for poorer psychosocial outcomes and quality of life. The current study compares peripheral blood cell analyses and psychosocial self-reports from parents of children being treated for cancer (n = 21) to parents of healthy children (n = 30).

METHODS

A blood sample was drawn from parents to analyze immune profiles. Parents also completed the Perceived Stress Scale (PSS), Medical Outcomes Study Short Form-36 (MOS), and Patient-Reported Outcomes Measurement Information System Short Form v1.0 Emotional Distress-Anxiety 8a, and Emotional Distress-Depression 8a (PROMIS). Mann-Whitney U tests and independent samples t-tests were conducted to examine differences in outcomes between parent groups.

RESULTS

Parents of children with cancer exhibited higher monocyte percentages in their peripheral blood compared to peers with healthy children. Parents of children with cancer also reported poorer psychosocial outcomes: higher perceived stress, higher anxiety and depression symptoms, more role disability resulting from emotional problems, poorer general and mental health, and poorer social functioning.

CONCLUSION

These findings support research that has shown a direct effect of chronic stress on the immune system. Symptoms reported by parents of children with cancer indicate unmet psychosocial needs that could potentially affect long-term health. Given the central role of parents in their children's cancer care, it is compelling to address and work to improve parent immunological and psychosocial well-being.

Association Between Inflammation and Appetite in Healthy Community-Dwelling Older Adults—An enable Study

Aging is associated with reduced appetite as well as a slight increase in pro-inflammatory status, which both might contribute to the development of malnutrition. We aimed to evaluate the association between inflammation based on serum C-reactive protein (CRP), and appetite in healthy community-dwelling older adults. In this cross-sectional study of 158 healthy and non-smoking persons (aged 75–85 years), appetite was assessed in personal interviews by a single question with five answer categories. As nobody reported (very) poor appetite, the remaining three categories were dichotomised into “(very) good” and “moderate” appetite. Fasting serum CRP was analysed according to standard procedures, values ≥ 5.0 mg/L were considered as inflammation. The association between inflammation and appetite was examined by binary logistic regression, unadjusted and adjusted for age, sex, waist circumference, leptin, depressive mood, number of medications, interleukin-6 and tumor necrosis factor-α. Appetite was very good in 27.8%, good in 58.9%, and moderate in 13.3% of participants. Inflammation was present in 10.8% overall, in 8.8% of those with (very) good and in 23.8% of those with moderate appetite (p = 0.038). In the unadjusted model, participants with inflammation were 3.2 times more likely to have moderate appetite (95%CI: 1.01–10.44, p = 0.047). In the adjusted model, the odds of having moderate appetite was 3.7 times higher in participants with inflammation, but no longer significant (95%CI: 0.77–18.55, p = 0.102). In healthy older people, we found hints for a potential association between increased levels of CRP and a slightly reduced appetite. More studies in larger samples are needed.

Effect of Mindfulness Versus Loving-kindness Training on Leukocyte Gene Expression in Midlife Adults Raised in Low-Socioeconomic Status Households

Objectives

People raised in low socio-economic status (SES) households are at an increased risk for physical illness in adulthood. A shift in gene expression profiles in the immune system is one biological mechanism thought to account for elevated disease susceptibility, with a frequently-investigated profile being the conserved transcriptional response to adversity (CTRA), characterized by increased expression of proinflammatory genes and decreased expression of antiviral and antibody-related genes.

Methods

The present study investigated, in a sample of at-risk midlife adults (N = 88), whether those randomized to learn loving-kindness meditation (LKM) in a 6-week workshop, would show a reduction in CTRA gene expression, compared to those randomized to learn mindfulness meditation (MM). We assessed emotions daily and hypothesized positive emotions to account for the expected effect of LKM on gene expression.

Results

Results showed significant group differences from pre- to post-intervention, yet in the opposite direction as hypothesized: Participants randomized to the MM group showed significant declines in CTRA gene expression, whereas those in the LKM group showed significant increases in CTRA gene expression. Both groups showed increases over the 6 weeks in daily reports of positive emotions, b=.007, p <.001 alongside decreases in negative emotions b=-.005, p <.001. Thus, positive emotions were not pursued as a candidate mediator of observed group effects.

Conclusion

This study is the first to examine whether the biological impact of childhood low-SES can be reversed in mid-life through meditation interventions. Results suggest mindfulness meditation may be a viable option for improving health outcomes in this at-risk population. Trial Registration: ClinicalTrials.gov NCT02400593.

Control over pathogen exposure and basal immunological activity influence disgust and pathogen-avoidance motivation

Disgust is reasoned to operate in conjunction with the immune system to help protect the body from illness. However, less is known about the factors that impact the degree to which individuals invest in pathogen avoidance (disgust) versus pathogen management (prophylactic immunological activity). Here, we examine the role that one's control over pathogen contact plays in resolving such investment trade-offs, predicting that (a) those from low control environments will invest less in pathogen-avoidance strategies and (b) investment in each of these two strategies will occur in a compensatory fashion (i.e. they will be traded off with one other). Across four studies, we found support for these predictions, using a variety of manipulations and measures. By providing novel insights into how one's control over pathogen exposure influences disgust sensitivity and immune system activity, the current research poses an important contribution to the literature on disgust, pathogen avoidance, and the immune system.

Social Media Use and Its Link to Physical Health Indicators

Social media use has become an integral part of many young adults' daily lives. Although much research has examined how social media use relates to psychological well-being, little is known about how it relates to physical health. To address this knowledge gap, the present research investigated how the amount of social media people use relates to various indices of physical health. Young adults provided a blood sample that was analyzed for C-reactive protein (CRP), a marker of chronic inflammation. They also completed self-report measures of social media use, somatic symptoms, illness-related physician or health center visits, and whether they sought medical care for infection-related illnesses in the last 3 months. Social media use was positively correlated with higher levels of CRP, more somatic symptoms, and more visits to the doctor or health centers for an illness. Although directionally consistent, the correlation with likelihood of seeking medical care for infection-related illnesses was nonsignificant (p = 0.061). All of these results held after controlling for factors such as sociodemographic information and depressive symptoms. Given the prevalence of social media use in daily life, these findings underscore the need for more research examining how social media use relates to physical health.

Partner's Perceived Social Support Influences Their Spouse's Inflammation: An Actor-Partner Analysis

Social support has been linked to lower cardiovascular morbidity and mortality. However, most studies have examined perceived support as an intrapersonal construct. A dyadic approach to social support highlights how interdependence between individuals within relationships, including partner perceptions and interactions, can influence one's health. This study's overall purpose was to test actor-partner models linking perceived social support to inflammation. Ninety-four cisgender married couples completed perceived support measures and had their blood drawn for CRP and IL-6 to produce an overall inflammatory index. The primary results indicate that only a partner's level of perceived support was related to lower inflammation in their spouse. Our sample size, although moderate for inflammatory studies, was probably not large enough to detect actor influences. These data highlight the importance of taking a dyadic perspective on modeling perceived support and its potential mechanism.

The Association Between Loneliness and Inflammation: Findings From an Older Adult Sample

Loneliness has been linked to poor mental and physical health outcomes. Past research suggests that inflammation is a potential pathway linking loneliness and health, but little is known about how loneliness assessed in daily life links with inflammation, or about linkages between loneliness and inflammation among older adults specifically. As part of a larger investigation, we examined the cross-sectional associations between loneliness and a panel of both basal and LPS-stimulated inflammatory markers. Participants were 222 socioeconomically and racially diverse older adults (aged 70-90 years; 38% Black; 13% Hispanic) systematically recruited from the Bronx, NY. Loneliness was measured in two ways, with a retrospective trait measure (the UCLA Three Item Loneliness Scale) and an aggregated momentary measure assessed via ecological momentary assessment (EMA) across 14 days. Inflammatory markers included both basal levels of C-reactive protein (CRP) and cytokines (IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α) and LPS-stimulated levels of the same cytokines. Multiple regression analyses controlled for age, body-mass index, race, and depressive symptoms. Moderation by gender and race were also explored. Both higher trait loneliness and aggregated momentary measures of loneliness were associated with higher levels of CRP (β = 0.16, p = 0.02; β = 0.15, p = 0.03, respectively). There were no significant associations between loneliness and basal or stimulated cytokines and neither gender nor race were significant moderators. Results extend prior research linking loneliness with systemic inflammation in several ways, including by examining this connection among a sample of older adults and using a measure of aggregated momentary loneliness.

Understanding associations between rumination and inflammation: A scoping review

A growing body of evidence suggests that rumination, or focused attention on mental representations of negative events, may have physiological consequences that adversely affect long term health. We conducted a scoping review on quantitative studies of humans examining associations between rumination and inflammation, which included 13 studies representing 14 samples and 1,102 unique participants. The review included 8 biomarkers measured in plasma, serum and saliva (C reactive protein, and C-C motif chemokine 11, interleukin (IL)- 1β, IL-4, IL-6, IL-8, IL-10 and tumor necrosis factor alpha). More consistent findings of an association between greater rumination and increased inflammation were found in studies that used experimental designs and manipulated rumination. Emerging research suggests rumination may interact with other factors (e.g., socioeconomic status, anxiety) to predict inflammation. This review offers an up to date synthesis of the emerging research focused on rumination and inflammation. The relationship between inflammation and rumination may be contingent on how rumination is conceptualized and measured, as well as the measure of inflammation (i.e., at rest/ in response to stress).

Psychological Stress During Childhood and Adolescence and Its Association With Inflammation Across the Lifespan: A Critical Review and Meta-Analysis

Psychological stress during childhood and adolescence increases risk of health problems across the lifecourse, and inflammation is implicated as an underlying mechanism. To evaluate the viability of this hypothesis, we used meta-analysis to quantify the association between childhood/adolescent stress and inflammation over the lifecourse. Furthermore, we addressed three unresolved conceptual questions: (a) Does the strength of this association change over the lifecourse? (b) Are different types of childhood/adolescent stressors differentially associated with inflammation? (c) And which components of the inflammatory response are involved? A systematic search identified 187 articles reporting 922 associations. Meta-analyses were conducted using a three-level multilevel approach and controlled for study quality, conversion confidence, and whether effect sizes were unadjusted or adjusted (n = 662, 72%). Results indicated a small but reliable overall adjusted association ( r ^ = .04 ) . The magnitude of the association strengthened across the lifecourse-effect sizes were smallest in studies that measured inflammation in childhoodr ^ = .02 and became progressively larger in studies of adolescencer ^ = .04 and adulthoodr ^ = .05 , suggesting the impact of early stress strengthens with time. By contrast, effect sizes did not vary by adversity type (socioeconomic disadvantage, maltreatment, other interpersonal stressors, and cumulative exposure across stressors), or component of inflammation (circulating biomarkers of low-grade inflammation vs. cytokine responses to microbial stimuli). Implications and future directions are discussed.

Inflammatory reactivity to the influenza vaccine is associated with changes in automatic social behavior

Recent evidence suggests differential patterns of social behavior following an inflammatory challenge, such that increases in inflammation may not uniformly lead to social withdrawal. Indeed, increases in inflammation have been associated with enhanced self-reported motivation to approach a specific close other, and greater neural sensitivity to positive social cues. However, no known studies have examined the association between inflammation in response to an inflammatory challenge and social behavior in humans, nor has past research examined specifically how approach and withdrawal behavior may differ based on whether the target is a close other or stranger. To address this, 31 participants (ages 18-24) received the influenza vaccine to elicit a low-grade inflammatory response. The morning before and approximately 24 h after the vaccine, participants provided a blood sample and completed a computer task assessing automatic (implicit) approach and withdrawal behavior toward a social support figure and strangers. Greater increases in the inflammatory cytokine interleukin-6 (IL-6) in response to the vaccine were associated with an increase in accuracy in avoiding strangers and a decrease in accuracy in approaching them. Increases in IL-6 were also associated with a decrease in reaction time to approach a support figure, but only when controlling for baseline IL-6 levels. There were no associations between change in IL-6 and changes in self-reported motivation to engage in social behavior with either close others, or strangers. Together, these findings reveal that increases in inflammation following the influenza vaccine are associated with automatic social behavior, especially behavior suggesting avoidance of unfamiliar social targets and ease in approaching a support figure. These data add to the growing literature suggesting that the association between inflammation and social behavior includes both social withdrawal and social approach, depending on the specific target.

Associations of High-Sensitivity C-Reactive Protein and Interleukin-6 with Depression in a Sample of Italian Adolescents During COVID-19 Pandemic

INTRODUCTION

Many studies highlighted the role of inflammation in the pathogenesis of depression, although not for every patient nor for every symptom. It is widely shared that stressors can increase inflammation and lead to depressive symptoms. Little is known about the symptom-specificity of the inflammation-depression link in adolescence, which we aimed to explore. The single symptom analysis is a core feature of the recent network approach to depression, supposing that psychiatric disorders consist of co-occurring symptoms and their tendency to cause each other.

PATIENTS AND METHODS

We recruited 52 adolescents diagnosed with a Depressive Disorder during the COVID-19 stressful period. We used regression analysis to measure associations between high sensitivity C-Reactive Protein (hs-CRP) and Interleukin-6 (IL-6) and depressive symptoms assessed by the Children's Depression Inventory 2 (CDI 2). For the study of symptom specificity, we selected 13 items from the CDI 2 Self Report corresponding with the DSM-5 diagnostic criteria for Major Depressive Disorder and we coded them as dichotomous variables to perform a regression analysis.

RESULTS

We found that a higher CDI 2-Parent Version total score was significantly predicted by higher hs-CRP (coefficient 3.393; p 0.0128) and IL-6 (coefficient 3.128; p 0.0398). The endorsement of the symptom self-hatred, measuring the DSM-5 symptom "feelings of worthlessness", was significantly predicted by hs-CRP (OR 10.97; 95% CI 1.29-93.08; p 0.0282).

CONCLUSION

A novel symptom-specificity emerged, with hs-CRP significantly predicting the endorsement of the symptom self-hatred, recognized as a core feature of adolescent depression, following the network theory. We considered it a possible phenotypic expression of one depression endophenotype previously causally linked to inflammation. Due to the limited sample size, these preliminary findings require confirmation with future research focusing on the relationship between inflammation and self-hatred and other central nodes of the depression network, representing an opportunity for targeting interventions on crucial symptoms.

Socioeconomic Status and Inflammation in Women with Early-stage Breast Cancer: Mediation by Body Mass Index

BACKGROUND

Breast cancer is the most common cancer among women in the US, and women of low socioeconomic status (SES) show markedly poorer outcomes than those of high SES. SES may influence health through inflammation, although links between SES and inflammatory biomarkers have not been investigated in women with breast cancer. This study tested the hypothesis that breast cancer patients of lower SES would show higher levels of inflammation than those of higher SES. BMI was examined as a mediator of this association.

METHODS

Women recently diagnosed with early-stage breast cancer (N = 194) were recruited before neoadjuvant or adjuvant therapy. Participants completed questionnaires and provided blood samples for immune assessment. SES was indexed by participants' self-reported education and annual household income, BMI was determined by height and weight measurements, and blood was assayed for inflammatory biomarkers linked with cancer outcomes: IL-6, CRP, TNF-α, and sTNF-RII. General linear models tested associations between SES and inflammation, and mediation models examined indirect effects through BMI.

RESULTS

Consistent with hypotheses, education status was associated with CRP, (F(2,185) = 4.72, p = 0.001), and sTNF-RII, (F(2,185) = 4.19, p = 0.02), such that lower education was associated with higher levels of both biomarkers. Further, BMI mediated the associations between education and CRP, (95% CIs [-0.62, -0.11; -0.76, -0.21]), sTNF-RII, (95% CIs [-0.09, -0.01; -0.10, -0.02]), and IL-6, (95% CIs [-0.32, -0.05; -0.38, -0.09]). Annual household income was not significantly associated with inflammation (ps > 0.25), and indirect effects on inflammation through BMI were not significant.

CONCLUSIONS

Lower education was associated with higher levels of inflammation in this sample, which may presage poor breast cancer-related and clinical outcomes. SES should inform the development of interventions targeting BMI and inflammation in breast cancer.

Cerebrospinal fluid cytokines in geriatric patients with depressive disorders: A retrospective case-control study

Central nervous system inflammation might play a role in patients with depressive disorders. This hypothesis is supported by studies reporting increased cerebrospinal fluid levels of the inflammatory markers interleukin (IL)-6, IL-8 and tumor necrosis factor alpha (TNF-α) in patients with ongoing depression. In this case-control study, we aimed to examine whether these findings also applied to depressed patients in a geriatric population. Cerebrospinal fluid cytokine analyses were performed on 15 patients (age >60 years) with depressive disorders and 45 age- and sex matched controls (patients with headache or idiopathic facial palsy). IL-6, IL-8, IL-10, TNF-α, monocyte chemoattractant protein-1 and transforming growth factor beta 1 were included in the statistical analyses. Patients with depression had significantly lower cerebrospinal fluid levels of IL-6 as compared to controls (p = 0.014) in the univariate analysis. The finding was, however, no longer statistically significant after correction for age and body mass index (p = 0.097). Overall, this study indicates that the cytokines included in this study are not significantly altered in geriatric patients with depression. Future studies exploring cerebrospinal fluid cytokine levels should include corrections for possible confounding factors.

Moderators of inflammation-related depression: a prospective study of breast cancer survivors

Inflammation has been shown to predict depression, but sensitivity to inflammation varies across individuals. Experimental studies administering potent pro-inflammatory agents have begun to characterize this sensitivity. However, risk factors for inflammation-associated depression in naturalistic contexts have not been determined. The present study examined key psychological and behavioral risk factors (state anxiety, perceived stress, negative affect, disturbed sleep, and childhood adversity) as potential moderators of the relationship between inflammation and depressive symptoms in a prospective longitudinal study of breast cancer survivors. Women with early stage breast cancer were recruited after completing primary cancer treatment (n_final = 161). Depressive symptoms, inflammatory markers (CRP, IL-6, and sTNF-RII), and key risk factors were assessed post treatment (T1), at 6 and 12-month follow-ups (T2 and T3), and during a final follow-up (TF) 3-6 years after T1; childhood adversity was measured only at T3. Inflammatory markers were combined into a single inflammatory index prior to analyses. Women who reported higher levels of state anxiety, perceived stress, negative affect, and/or sleep disturbance at T1 (post-treatment) exhibited higher depressive symptoms at times when inflammation was higher than typical (interaction βs ranged from .06 to .08; all ps < .014). Results demonstrate the relevance of these risk factors for understanding inflammation-associated depression in a clinical context and could inform targeted strategies for prevention and treatment among at-risk populations.

From childhood maltreatment to adult inflammation: Evidence for the mediational status of social anxiety and low positive affect

Prior work has established a robust association between childhood maltreatment and systemic inflammatory activation later in life; however, the mechanisms involved in this process remain incompletely understood. The purpose of this investigation was to examine potential mechanistic roles for social anxiety (SA) symptoms and low positive affect (PA) in the path from childhood maltreatment to elevations in circulating interleukin (IL)-6, a common biomarker of inflammatory activation. In addition, building on prior work establishing linkages between mindful awareness and reductions in systemic inflammation, we examined the potential role of trait mindfulness as a moderator of the relationships among childhood maltreatment, SA, low PA, and IL-6. A serial mediation model utilizing a large epidemiologic dataset (final N ​= ​527) supported our central hypothesis that the direct effect of childhood maltreatment on IL-6 was fully serially statistically mediated by SA symptoms and low PA (but not high negative affect). Additionally, results indicated that individuals falling in the upper versus lower quartiles of SA symptoms demonstrated significantly elevated concentrations of IL-6, a finding that has not been previously reported. Trait mindfulness moderated the association between low PA and IL-6, to the exclusion of any paths related to negative affect. Additionally, results indicated that the effect of child maltreatment on IL-6 bypasses SA to indirectly impact IL-6 via negative affect. Overall, we conclude that childhood maltreatment and SA symptoms have a significant influence on IL-6, albeit indirectly via low PA, and the influence of PA on IL-6 may be uniquely susceptible to influence by individual differences in mindfulness.

Association Between Systemic Inflammation and Individual Symptoms of Depression: A Pooled Analysis of 15 Population-Based Cohort Studies

OBJECTIVE

Evidence from anti-inflammatory drug trials for the treatment of depression has been inconsistent. This may be ascribed to the differing symptom-specific effects of inflammation. Accordingly, the authors explored the associations between systemic inflammation and an array of individual symptoms of depression across multiple studies.

METHODS

This random-effects pooled analysis included 15 population-based cohorts and 56,351 individuals age 18 years and older. Serum or plasma concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) were measured at baseline. Using validated self-report measures, 24 depressive symptoms were ascertained in 15 cross-sectional studies, and, in seven cohorts, were also assessed at follow-up (mean follow-up period, 3.2 years).

RESULTS

The prevalence of depressive symptoms ranged from 1.1% (suicidal ideation) to 21.5% (sleep problems). In cross-sectional analyses, higher concentrations of CRP were robustly associated with an increased risk of experiencing four physical symptoms (changes in appetite, felt everything was an effort, loss of energy, sleep problems) and one cognitive symptom (little interest in doing things). These associations remained after adjustment for sociodemographic variables, behavioral factors, and chronic conditions; in sex- and age-stratified analyses; in longitudinal analyses; when using IL-6 as the inflammatory marker of interest; in depressed individuals; and after excluding chronically ill individuals. For four exclusively emotional symptoms (bothered by things, hopelessness about the future, felt fearful, life had been a failure), the overall evidence was strongly against an association with inflammation.

CONCLUSIONS

These findings suggest symptom-specific rather than generalized effects of systemic inflammation on depression. Future trials exploring anti-inflammatory treatment regimens for depression may benefit from targeting individuals presenting with symptom profiles characterized by distinct inflammation-related physical and cognitive symptoms.

Immunological Trajectories of White Blood Cells from Adolescence to Adulthood: Description and Determinants

Background: The immune system gradually matures early in life in the face of internal and external stimuli. Whether the immune responses are lasting and stable during the course of life is still unclear. Methods: As part of the EPITeen cohort, 1183 adolescents were prospectively evaluated at the ages of 13, 17, 21, 24 and 27. Sociodemographic, behavioral and clinical data were collected by self- and face-to-face-administered questionnaires, along with a physical examination comprising anthropometric measurements and blood sample collections. Mixed-effects models were used to identify individual trajectories of white blood cells (WBC) and finite Gaussian mixture models were used to identify the clusters of individual trajectories. Results: Participants were allocated into six clusters based on the individual trajectories of WBC distribution. Higher Inflammatory Activation Cluster (11.4%) had the highest total WBC count and neutrophils percentage, as well as the lowest percentage of lymphocytes. These participants had significantly higher odds of being overweight [OR = 2.44, 95%CI:1.51–3.92]. Lowest Levels of WBC Cluster (24.1%) had the lowest total WBC count, being characterized by a higher participation on sports [OR = 1.54, 95%CI:1.12–2.13]. Highest Proportion of Eosinophils Cluster (20.1%) had the highest eosinophils percentage and the highest likelihood of having been diagnosed with a chronic disease [OR = 2.11, 95%CI:1.43–3.13], namely “asthma or allergies” [OR = 14.0 (1.73, 112.2]. Lowest Proportion of Eosinophils Cluster (29.1%) had the lowest percentage of eosinophils and basophils, as well as the highest lymphocyte proportion. Participants in the Undefined Cluster (13.8%) showed the highest percentage of monocytes and basophils and were also characterized by significant lower odds of having parents with 7–9 years of schooling [OR = 0.56, (0.32, 0.99]. Conclusions: In this study we identified distinct immunological trajectories of WBC from adolescence to adulthood that were associated with social, clinical and behavioral determinants. These results suggest that these immunological trajectories are defined early in life, being dependent on the exposures.