Assessment of Brain Derived Neurotrophic Factor in hair to study stress responses: A pilot investigation

Long-term stress exposure, cortisol level and cardiovascular activity and reactivity: Observations in patients with fibromyalgia

Previous research suggested that exposure to long-lasting or repeated laboratory stressors may lead to rearrangement of cardiovascular control, with a shift of regulation mechanisms from dominant cardiac to dominant vascular influences between the early and late response phases, respectively. This study investigated whether similar rearrangement occurs during life stress accompanying chronic disease by analyzing also associations between cortisol level and cardiovascular variables in patients with fibromyalgia (FM). In 47 women with FM and 36 healthy women (HW), cardiovascular recordings were taken during active body posture changes (sitting, lying down, and standing). Moreover, hair cortisol concentration (HCC) was obtained. During standing, which involved orthostatic challenge, FM patients showed higher total peripheral resistance (TPR) but lower stroke volume (SV), cardiac output (CO), and baroreflex sensitivity than HW. During sitting and lying down, TPR was more closely associated with blood pressure (BP) than CO in FM patients; in contrast, CO was more closely associated with BP than TPR in HW. HCC correlated positively with TPR and BP in FM patients, but negatively with TPR and BP and positively with SV and CO in HW. Results suggest that chronic disease-related stress is associated with alterations in cardiovascular regulation toward greater involvement of vascular than cardiac mechanisms in BP control. Stress-related cortisol release may contribute to the long-term rearrangement of autonomic regulation. At the behavioral level, the dominance of vascular over cardiovascular control may relate to reduced somatic mobilization during an active fight-flight response in favor of passive and behaviorally immobile coping.

Hair brain-derived neurotrophic factor (BDNF) as predictor of developing psychopathological symptoms in childhood

BACKGROUND

Dysregulation in the expression of neurotrophins is implicated in the pathophysiology of several mental disorders. Peripheral brain-derived neurotrophic factor (BDNF) can be measured in hair and might represent a marker of adequate neuroplasticity regulation. In early developmental periods, neuroplasticity regulation might be particularly important, but BDNF markers have not yet been analyzed in this regard. We used the hair-BDNF concentration (HBC) to investigate the prediction of emerging symptoms of anxiety/depressive and attention-deficit hyperactivity disorder (ADHD) in the developmentally crucial period from preschool to school age.

METHODS

117 children (58 girls, 59 boys) participated in a longitudinal study at the ages of 4-5 (T1) and 8 (T2) years. At T1, HBC was measured in a 3 cm hair segment. At T1 and T2, symptom domains were assessed using a multi-method (clinical interview, questionnaire) and multi-informant approach.

RESULTS

T1 HBC was significantly negatively associated with T1 anxiety/depressive symptoms (r = -0.27) and predicted T2 anxiety disorder symptoms (r = -0.34) after controlling for the T1 symptoms. T1 HBC also predicted T2 depressive disorder symptoms (r = -0.18) but was not associated with ADHD symptom development.

LIMITATIONS

BDNF hair analysis is a new method with a not yet large number of studies on methodological issues. Our study adds evidence to the validity of the method.

CONCLUSIONS

Prediction of anxiety/depressive symptom development by HBC was shown. As this study was the first to use HBC in this context, cross-validation is necessary and worthwhile. HBC might prove to constitute a useful, non-invasive early marker of risk for anxiety/depressive disorders in childhood.

Intricate role of sleep deprivation in modulating depression: focusing on BDNF, VEGF, serotonin, cortisol, and TNF-α

In this review article, we aimed to discuss intricate roles of SD in modulating depression in preclinical and clinical studies. Decades of research have shown the inconsistent effects of SD on depression, focusing on SD duration. However, inconsistent role of SD seems to be more complicated, and SD duration cannot be the only one factor. Regarding this issue, we chose some important factors involved in the effects of SD on cognitive functions and mood including brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), serotonin, cortisol, and tumor necrosis factor-alpha (TNF-α). It was concluded that SD has a wide-range of inconsistent effects on BDNF, VEGF, serotonin, and cortisol levels. It was noted that BDNF diurnal rhythm is significantly involved in the modulatory role of SD in depression. Furthermore, the important role of VEGF in blood-brain barrier permeability which is involved in modulating depression was discussed. It was also noted that there is a negative correlation between cortisol and BDNF that modulates depression. Eventually, it was concluded that TNF-α regulates sleep/wake cycle and is involved in the vulnerability to cognitive and behavioral impairments following SD. TNF-α also increases the permeability of the blood-brain barrier which is accompanied by depressive behavior. In sum, it was suggested that future studies should focus on these mechanisms/factors to better investigate the reasons behind intricate roles of SD in modulating depression.

The impact of perceived stress on the hair follicle: Towards solving a psychoneuroendocrine and neuroimmunological puzzle

While popular belief harbors little doubt that perceived stress can cause hair loss and premature graying, the scientific evidence for this is arguably much thinner. Here, we investigate whether these phenomena are real, and show that the cyclic growth and pigmentation of the hair follicle (HF) provides a tractable model system for dissecting how perceived stress modulates aspects of human physiology. Local production of stress-associated neurohormones and neurotrophins coalesces with neurotransmitters and neuropeptides released from HF-associated sensory and autonomic nerve endings, forming a complex local stress-response system that regulates perifollicular neurogenic inflammation, interacts with the HF microbiome and controls mitochondrial function. This local system integrates into the central stress response systems, allowing the study of systemic stress responses affecting organ function by quantifying stress mediator content of hair. Focusing on selected mediators in this "brain-HF axis" under stress conditions, we distill general principles of HF dysfunction induced by perceived stress.

Hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness and distress in chronic tinnitus

The role of stress and its neuroendocrine mediators in tinnitus is unclear. In this study, we measure cortisol as an indicator of hypothalamus–pituitary–adrenal (HPA) axis alterations and brain-derived neurotrophic factor (BDNF) as a marker of adaptive neuroplasticity in hair of chronic tinnitus patients to investigate relationships with tinnitus-related and psychological factors. Cross-sectional data from chronic tinnitus inpatients were analyzed. Data collection included hair sampling, pure tone audiometry, tinnitus pitch and loudness matching, and psychometric questionnaires. Elastic net regressions with n-fold cross-validation were performed for cortisol (N = 91) and BDNF (N = 87). For hair-cortisol (R² = 0.10), the strongest effects were sampling in autumn and body-mass index (BMI) (positive), followed by tinnitus loudness (positive) and smoking (negative). For hair-BDNF (R² = 0.28), the strongest effects were hearing aid use, shift work (positive), and tinnitus loudness (negative), followed by smoking, tinnitus-related distress (Tinnitus Questionnaire), number of experienced traumatic events (negative), and physical health-related quality of life (Short Form-12 Health Survey) (positive). These findings suggest that in chronic tinnitus patients, higher perceived tinnitus loudness is associated with higher hair-cortisol and lower hair-BDNF, and higher tinnitus-related distress with lower hair-BDNF. Regarding hair-BDNF, traumatic experiences appear to have additional stress-related effects, whereas hearing aid use and high physical health-related quality of life appear beneficial. Implications include the potential use of hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness or distress and the need for intensive future research into chronic stress-related HPA axis and neuroplasticity alterations in chronic tinnitus.

Psychological Treatment Effects Unrelated to Hair-Cortisol and Hair-BDNF Levels in Chronic Tinnitus

BACKGROUND

Currently, there are no objective markers to measure treatment efficacy in chronic (distressing) tinnitus. This study explores whether stress-related biomarkers cortisol and brain-derived neurotrophic factor (BDNF) measured in hair samples of chronic tinnitus patients change after compact multimodal tinnitus-specific cognitive behavioral therapy.

METHODS

In this longitudinal study, hair-cortisol and hair-BDNF levels, self-reported tinnitus-related distress (Tinnitus Questionnaire; TQ), and perceived stress (Perceived Stress Questionnaire; PSQ-20) were assessed before and 3 months after 5 days of treatment in N = 80 chronic tinnitus patients. Linear mixed-effects models with backward elimination were used to assess treatment-induced changes, and a cross-lagged panel model (structural equation model) was used for additional exploratory analysis of the temporal associations between TQ and hair-BDNF.

RESULTS

At follow-up, a reduction in TQ (p < 0.001) and PSQ-20 scores (p = 0.045) was observed, which was not influenced by baseline hair-cortisol or hair-BDNF levels. No changes in biomarker levels were observed after treatment. The exploratory analysis tentatively suggests that a directional effect of baseline TQ scores on hair-BDNF levels at follow-up (trend; p = 0.070) was more likely than the opposite directional effect of baseline hair-BDNF levels on TQ scores at follow-up (n.s.).

DISCUSSION

While the treatment effectively reduced tinnitus-related distress and perceived stress in chronic tinnitus patients, this effect was not mirrored in biological changes. However, the lack of changes in hair-cortisol and hair-BDNF levels might have been influenced by the treatment duration, follow-up interval, or confounding medical factors, and therefore must be interpreted with caution. The relationship between tinnitus-related distress and hair-BDNF levels should be explored further to obtain a better understanding of stress-related effects in chronic tinnitus.

Trauma-focused psychodynamic therapy and STAIR Narrative Therapy of post-traumatic stress disorder related to childhood maltreatment: trial protocol of a multicentre randomised controlled trial assessing psychological, neurobiological and health economic outcomes (ENHANCE)

INTRODUCTION

Success rates of psychotherapy in post-traumatic stress disorder related to childhood maltreatment (PTSD-CM) are limited.

METHODS AND ANALYSIS

Observer-blind multicentre randomised clinical trial (A-1) of 4-year duration comparing enhanced methods of STAIR Narrative Therapy (SNT) and of trauma-focused psychodynamic therapy (TF-PDT) each of up to 24 sessions with each other and a minimal attention waiting list in PTSD-CM. Primary outcome is severity of PTSD (Clinician-Administered PTSD Scale for DSM-5 total) assessed by masked raters. For SNT and TF-PDT, both superiority and non-inferiority will be tested. Intention-to-treat analysis (primary) and per-protocol analysis (secondary). Assessments at baseline, after 10 sessions, post-therapy/waiting period and at 6 and 12 months of follow-up. Adult patients of all sexes between 18 and 65 years with PTSD-CM will be included. Continuing stable medication is permitted. To be excluded: psychotic disorders, risk of suicide, ongoing abuse, acute substance related disorder, borderline personality disorder, dissociative identity disorder, organic mental disorder, severe medical conditions and concurrent psychotherapy. To be assessed for eligibility: n=600 patients, to be e randomly allocated to the study conditions: n=328. Data management, randomisation and monitoring will be performed by an independent European Clinical Research Infrastructure Network (ECRIN)-certified data coordinating centre for clinical trials (KKS Marburg). Report of AEs to a data monitoring and safety board. Complementing study A-1, four inter-related add-on projects, including subsamples of the treatment study A-1, will examine (1) treatment integrity (adherence and competence) and moderators and mediators of outcome (B-1); (2) biological parameters (B-2, eg, DNA damage, reactive oxygen species and telomere shortening); (3) structural and functional neural changes by neuroimaging (B-3) and (4) cost-effectiveness of the treatments (B-4, costs and utilities).

ETHICS AND DISSEMINATION

Approval by the institutional review board of the University of Giessen (AZ 168/19). Following the Consolidated Standards of Reporting Trials statement for non-pharmacological trials, results will be reported in peer-reviewed scientific journals and disseminated to patient organisations and media.

TRIAL REGISTRATION NUMBER

DRKS 00021142.

Effect of repetitive transcranial magnetic stimulation on the cognitive impairment induced by sleep deprivation: a randomized trial

OBJECTIVE

Currently, an efficient method for improving cognitive impairment due to sleep deprivation (SD) is lacking. The aim of this study is to evaluate the effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) during SD on reversing the adverse effects of SD.

METHODS

A total of 66 healthy people were randomized into the rTMS group and sham group. Both groups were deprived of sleep for 24 h. During SD, participants were asked to complete several cognitive tasks and underwent mood assessments. Saliva cortisol levels, plasma concentrations of brain-derived neurotrophic factor (BDNF), precursor BDNF (proBDNF), and tissue-type plasminogen activator (tPA), and frontal blood activation were detected before and after SD. The rTMS group received real rTMS stimulation for 2 sessions of 10 Hz rTMS (40 trains of 50 pulses with a 20-second intertrain interval) to the left dorsolateral prefrontal cortex and the sham group received sham stimulation during SD.

RESULTS

Twenty-four hours of SD induced a reduced accuracy in the n-back task, increases in both anxiety and depression, increased cortisol levels, decreased frontal blood activation and decreased BDNF levels in healthy people. Notably, rTMS improved the hyperactivity of the hypothalamic-pituitary-adrenal axis and decreased frontal blood activation induced by SD, and reduced the consumption of plasma proBDNF.

CONCLUSIONS

Twenty-four hours of SD induced a cognitive impairment. The administration of high-frequency rTMS during sleep deprivation exerted positive effects on HPA axis and frontal activation and might help alleviate cognitive impairment in the long term.

Minimally-invasive methods for examining biological changes in response to chronic stress: A scoping review

BACKGROUND

Nurse researchers are increasingly interested in incorporating biological indicators related to chronic stress, or repeated or constant exposure to psychological stressors. Minimally invasive collection methods may improve access to vulnerable populations.

OBJECTIVE

To map biological indicators measured through minimally invasive methods investigating biological changes in response to chronic stress.

DESIGN, DATA SOURCES, AND METHODS

The paper seeks to answer two questions: What are the characteristics of the minimally-invasive methods used to measure the biological correlates of chronic stress? What are the limitations regarding the use of the minimally-invasive methods and/or biological indicators identified above? Authors completed a scoping review following guidelines from the Joanna Briggs Institute Manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews. A literature search was completed in PubMed, PsycINFO, and Scopus. 2518 articles were screened and 145 studies were included. Data were extracted using a standardized extraction tool, compiled, and coded.

RESULTS

Studies included minimally-invasive methods to measure the hypothalamic-adrenal-pituitary axis (N = 173), immune and inflammatory markers (N = 118), and adult neurogenesis (N = 6). Cortisol was most frequently measured (N = 136), usually in saliva (N = 86). Studies included a variety of limitations for the methods and indicators, including concerns about timing and accuracy of collection, frequency of sampling, and controlling for acute stressors.

CONCLUSIONS

Nurse researchers have access to many minimally-invasive methods to measure altered biological processes related to chronic stress. A gap identified by this review is the paucity of minimally-invasive methods for investigating neurogenesis; the measurement of brain derived neurotrophic factor in plasma is a distal proxy and further research is needed to test the response of peripheral levels to psychosocial stress interventions. Additionally, while this scoping review allows nurse researchers to consider possible biological indicators to include in their research, future research is still needed on some of the basic premises of stress research, including agreement on the conceptualization of chronic stress.

Jigsaw Puzzling Taps Multiple Cognitive Abilities and Is a Potential Protective Factor for Cognitive Aging

Prevention of neurocognitive disorders is currently one of the greatest unmet medical challenges. The cognitive effects of solving jigsaw puzzles (JPs) have not been studied so far, despite its frequent use as a leisure activity in all age cohorts worldwide. This study aimed at closing this gap between a lack of science and a frequent real-world use by investigating the cognitive abilities recruited by JP as well as the cognitive benefits of lifetime and 30-day JP experience. A total of 100 cognitively healthy adults (≥50 years of age) were randomized to either a 30-day home-based JP intervention (≥1 h/day) plus four sessions of cognitive health counseling (JP group) or four sessions of cognitive health counseling only (counseling group). We measured global visuospatial cognition by averaging the scores of eight z-standardized visuospatial cognitive abilities (perception, constructional praxis, mental rotation, speed, flexibility, working memory, reasoning, and episodic memory). JP skill was assessed with an untrained 40 piece JP and lifetime JP experience with retrospective self-report. JP skill was associated with all assessed cognitive abilities (rs ≥ 0.45, ps < 0.001), and global visuospatial cognition (r = 0.80 [95% CI: 0.72–0.86], p < 0.001). Lifetime JP experience was associated with global visuospatial cognition, even after accounting for other risk and protective factors (β = 0.34 [95% CI: 0.18–0.50], p < 0.001). The JP group connected on average 3589 pieces in 49 h. Compared to the counseling group, they improved in JP skill (Cohen’s d = 0.38 [95% CI: 0.21–0.54], p < 0.001), but not in global visuospatial cognition (Cohen’s d = -0.08, [CI: -0.27 to 0.10], p = 0.39). The amount of jigsaw puzzling was related to changes in global visuospatial cognition within the JP group, only after accounting for baseline performance (β = 0.33 [95% CI: 0.02–0.63], p = 0.03). In sum, our results indicate that jigsaw puzzling strongly engages multiple cognitive abilities and long-term, but not short-term JP experiences could relevantly benefit cognition.

Trial Registration:ClinicalTrials.govIdentifier: NCT02667314

FGF21 regulates insulin sensitivity following long-term chronic stress

Objective

Post-traumatic stress disorder (PTSD) increases type 2 diabetes risk, yet the underlying mechanisms are unclear. We investigated how early-life exposure to chronic stress affects long-term insulin sensitivity.

Methods

C57Bl/6J mice were exposed to chronic variable stress for 15 days (Cvs) and then recovered for three months without stress (Cvs3m).

Results

Cvs mice showed markedly increased plasma corticosterone and hepatic insulin resistance. Cvs3m mice exhibited improved whole-body insulin sensitivity along with enhanced adipose glucose uptake and skeletal muscle mitochondrial function and fatty acid oxidation. Plasma FGF21 levels were substantially increased and associated with expression of genes involved in fatty acid oxidation and formation of brown-like adipocytes. In humans, serum FGF21 levels were associated with stress coping long time after the exposure.

Conclusions

Early-life exposure to chronic stress leads to long term improvements in insulin sensitivity, oxidative metabolism and adipose tissue remodeling. FGF21 contributes to a physiological memory mechanism to maintain metabolic homeostasis.

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Early-life exposure of mice to stress (CVS) causes acute insulin resistance but improves long-term insulin sensitivity.

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3 months after stress, mice had enhanced adipose glucose uptake and higher skeletal muscle mitochondrial function.

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Plasma FGF21 and gene expression for formation of brown-like adipocytes were substantially increased long after stress.

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In humans, serum FGF21 levels were associated with the ability to cope with stress long time after the exposure.