Silja Bellingrath

Chronic work stress and exhaustion is associated with higher allostastic load in female school teachers

Epidemiological studies have shown that chronic work stress or unfavourable psychosocial work conditions are prospectively associated with different adverse health outcomes. The aim of the present cross-sectional study was to investigate the relationship between work-related chronic stress as well as exhaustion and a cumulative measure of physiological wear-and-tear called allostatic load (AL). AL could be a possible biological pathway for how chronic work stress and exhaustion lead to health impairments in the long run. As the teaching profession has been proposed to be a potentially high stressful occupation, chronic work stress (effort-reward-imbalance) and exhaustion were assessed in 104 female school teachers. AL was first analyzed according to McEwens classical model comprised of ten parameters including cortisol, epinephrine and norepinephrine, dehydroepiandrosterone-sulphate (DHEA-S), waist/hip-ratio (WHR), glycosylated haemoglobin (HbA1c), high-density lipoprotein (HDL), total cholesterol/HDL-ratio, and systolic and diastolic blood pressure. Additionally it was extended to include tumor-necrosis-factor-α (TNF-α), C-reactive protein (CRP), fibrinogen, D-dimer, percent-body-fat, triglycerides, and glucose levels. A substantial proportion of our sample was highly exhausted whereas relatively few teachers showed high effort-reward-imbalance. AL scores were significantly higher in women high on effort-reward-imbalance or suffering from exhaustion. Although all teachers had been in a good health status, chronic work stress as well as exhaustion appears to be associated with changes in a multi-system summary indicator of physiological risk.

Cortisol dysregulation in school teachers in relation to burnout, vital exhaustion, and effort–reward-imbalance

We analyzed whether burnout and vital exhaustion or job-related chronic stress is associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation in school teachers (N=135; 25-63 years; mean age 46.1+/-9.20 years). Participants collected seven saliva samples (0, 30, 45, and 60 min after awakening, 11a.m., 3 p.m., 8 p.m.) on 2 working days, 1 leisure day, and after pre-medication with 0.25mg dexamethasone (very low-dose dexamethasone suppression test) to assess basal cortisol day profiles and HPA axis negative feedback sensitivity. No associations were found between basal cortisol activity and burnout (Maslach burnout inventory, teacher burnout scale), vital exhaustion (Appels vital exhaustion questionnaire), or any component of Siegrists effort-reward-imbalance model. However, after dexamethasone higher burnout and vital exhaustion and lower reward were significantly related to stronger cortisol suppression, pointing to altered HPA axis negative feedback sensitivity. Though, all teachers were working and in a good health status, burnout/exhaustion as well as facets of the ERI model appear to be associated with subtle dysregulation, manifested as heightened HPA axis negative feedback although not in basal cortisol day profiles.

The cortisol awakening response (CAR) across the female menstrual cycle

The cortisol awakening response (CAR) has been established as a useful marker of hypothalamus-pituitary-adrenal (HPA) axis activity and has become a standard tool for stress research in ambulatory settings. Although much knowledge has been accumulated on a variety of factors modulating the CAR, the impact of the female menstrual cycle, especially during ovulation, still remains unclear. To the best of our knowledge, this is the first study that measured the CAR during menses, the follicular phase, ovulation and the luteal phase in a repeated measurement design. For this purpose, a final sample of 29 naturally cycling, healthy, non-smoking, and medication-free women collected saliva samples directly after awakening as well as 30, 45, and 60 min later during each of the four different phases. To determine the timing of ovulation, an ambulatory chromatographic ovulation test kit was applied. A repeated measurements ANOVA resulted in a significant interaction effect sample × cycle phase (p=0.04), with the highest awakening response during ovulation. While awakening cortisol levels were comparable across the four cycle phases (p=n.s.), the net increase was significantly elevated during ovulation (p=0.05). Our data also confirmed earlier cross-sectional results reporting no differences in the CAR between the follicular and luteal phase. Finally, a concurrent assessment of mood applying the POMS (Profile of Mood States) yielded no differences across the four cycle phases (all p=n.s.). In sum, the present data points to the idea that the CAR is elevated during ovulation, an effect which is presumably mediated by elevated sex steroid levels during the ovulation period.

Effort-reward-imbalance and overcommitment are associated with hypothalamus–pituitary–adrenal (HPA) axis responses to acute psychosocial stress in healthy working schoolteachers

In this study, we examined HPA axis responses to acute psychosocial stress in relation to effort-reward-imbalance (ERI) and overcommitment (OC) to test whether chronic stress at work is accompanied by altered HPA axis stress responses in teachers. According to Siegrists work stress model, ERI reflects stress due to a lack of reciprocity between personal costs and gains at work, whereas OC is conceptualized as a personality trait mainly characterized by the inability to withdraw from work obligations. Fifty-three medication-free, non-smoking, healthy teachers (33 women, 20 men, 29-63 years, mean age 49.9+/-8.58 years) were confronted with the Trier Social Stress Test (TSST), a widely used standardized stress protocol to induce acute psychosocial stress in the laboratory. ACTH (five samples), total plasma (six samples) and free salivary cortisol (eight samples) were repeatedly measured before and after challenge. In the total group, ERI and OC were only marginally associated with HPA axis responses to acute stress. However, in the subgroup of responders (N=30) high levels of OC were significantly associated with lower ACTH (p=0.03) as well as plasma (p=0.02) and salivary cortisol (p<0.001) responses and results remained significant controlling for depressive symptoms. When additionally controlling for acute perceived stressfulness of the TSST, significant associations between OC and HPA axis responses emerged in responders as well as the total study sample. In respect to ERI, higher stress levels were solely related to significantly stronger plasma cortisol increases after TSST exposure, but this effect became non-significant controlling for depressive symptomatology. In sum, our findings support the notion of HPA axis hyporeactivity in highly overcommitted schoolteachers.

Association between burnout and circulating levels of pro- and anti-inflammatory cytokines in schoolteachers

OBJECTIVE The burnout syndrome has been associated with an increased risk of cardiovascular disease. The physiological mechanisms potentially involved in this link are underexplored. Knowing that a chronic low-grade systemic inflammatory state contributes to atherosclerosis, we investigated circulating cytokine levels in relation to burnout symptoms. METHODS We studied 167 schoolteachers (median, 48 years; range, 23-63 years; 67% women) who completed the Maslach Burnout Inventory with its three subscales emotional exhaustion (EE), lack of accomplishment (LA), and depersonalization (DP). Levels of the proinflammatory cytokine tumor necrosis factor (TNF)-alpha and of the anti-inflammatory cytokines interleukin (IL)-4 and IL-10 were determined in fasting morning plasma samples. The TNF-alpha/IL-4 ratio and the TNF-alpha/IL-10 ratio were computed as two indices of increased inflammatory activity. Analyses were adjusted for demographic factors, medication, lifestyle factors (including sleep quality), metabolic factors, and symptoms of depression and anxiety. RESULTS Higher levels of total burnout symptoms aggregating the EE, LA, and DP subscales independently predicted higher TNF-alpha levels (DeltaR(2)=.024, P=.046), lower IL-4 levels (DeltaR(2)=.021, P=.061), and a higher TNF-alpha/IL-4 ratio (DeltaR(2)=.040, P=.008). Higher levels of LA predicted decreased IL-4 levels (DeltaR(2)=.041, P=.008) and a higher TNF-alpha/IL-4 ratio (DeltaR(2)=.041, P=.007). The categorical dimensions of the various burnout scales (e.g., burnout yes vs. no) showed no independent relationship with any cytokine measure. CONCLUSION Burnout was associated with increased systemic inflammation along a continuum of symptom severity rather than categorically. Given that low-grade systemic inflammation promotes atherosclerosis, our findings may provide one explanation for the increased cardiovascular risk previously observed in burned-out individuals.

Healthy working school teachers with high effort–reward-imbalance and overcommitment show increased pro-inflammatory immune activity and a dampened innate immune defence

To test whether chronic work stress is accompanied by altered immune functioning, changes in lymphocyte subsets and in lymphocyte production of cytokines were examined in reaction to acute psychosocial stress. Work stress was measured according to Siegrists effort-reward-imbalance (ERI) model. ERI reflects stress due to a lack of reciprocity between costs and gains at work. Overcommitment (OC) is conceptualized as a dysfunctional coping pattern mainly characterized by the inability to withdraw from work obligations. Fifty-five healthy teachers (34 women, 21 men, mean age 50.0 ± 8.47 years) were exposed to a standardized laboratory stressor (Trier Social Stress Test). Lymphocyte subset counts and lymphocyte production of tumor-necrosis-factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, -4, -6 and -10 were measured before and after challenge. High levels of ERI and OC were associated with lower natural killer (NK) cell (CD16+/56+) numbers whereas high levels of OC were related to a lower increase in T-helper cells (CD4+) after stress. Furthermore, subjects with higher ERI showed an overall increased pro-inflammatory activity, with higher TNF-α production at both time points and elevated pre-stress IL-6 production. IL-10 production decreased with higher ERI after stress. The ratios of TNF-α/IL-10 and IL-6/IL-10 were significantly increased in subjects high on ERI. Finally, OC was associated with higher IL-2 production post-stress. The present findings suggest a dampened innate immune defence, reflected in lower NK cell numbers together with an increased pro-inflammatory activity in teachers high on ERI and OC. Such pathways could partly be responsible for the increased vulnerability for stress-related diseases in individuals suffering from chronic work stress.

Cortisol Responses to Naturalistic and Laboratory Stress in Student Teachers: Comparison with a Non‐stress Control Day

Ambulatory assessments of hypothalamus-pituitary-adrenal axis responses to acute natural stressors yield evidence on stress regulation with high ecological validity. Sampling of salivary cortisol is a standard technique in this field. In 21 healthy student teachers, we assessed cortisol responses to a demonstration lesson. On a control day, sampling was repeated at analogous times. Additionally, the cortisol awakening response (CAR) was assessed on both days. Participants were also exposed to a laboratory stressor, the Trier Social Stress Test, and rated their individual levels of chronic work stress. In pre-to-post-stress assessment, cortisol levels declined after the lesson. However, post-stress cortisol levels were significantly higher compared with those on the control day. Also, the Trier Social Stress Test yielded higher cortisol responses when using the control day as reference baseline. Associations between the CAR and chronic stress measures were observed solely on the control day. There were no significant associations between cortisol responses to the natural and laboratory stressors. Our results indicate that a control day might be an important complement in laboratory but especially in ambulatory stress research. Furthermore, associations between chronic stress measures and the CAR might be obscured by acute stress exposure. Finally, responses to the laboratory stressor do not seem to mirror natural stress responses.

Deficiencies of the T and natural killer cell system in major depressive disorder. T regulatory cell defects are associated with inflammatory monocyte activation

BACKGROUND In a previous study, we found an up-regulated inflammatory monocyte gene expression profile in major depressive disorder (MDD) patients aged ⩾ 28 years and a down-regulated inflammatory gene expression profile in MDD patients aged<28 years. In the same sample of patients, we aimed to investigate immune dysregulation in the lymphocyte arm of the immune system, particularly in the context of the described monocyte (de-)activation states. METHODS From deep frozen leukocytes, circulating percentages of monocytes, lymphocytes, B, T, and natural killer (NK) cells, and various functional subsets of T and T helper (Th) cells (Th1, Th2, Th17, and natural T regulatory cells) were measured in N=50 MDD patients and N=58 age- and gender-matched healthy controls (HC). In addition, serum levels of interleukin (IL)-6, sCD25, IL-7, IL-3, SCF, IGF-BP2, and EGF were evaluated. RESULTS MDD patients were in general characterized by an impaired maturation of Th2 cells, Th17 cells, and NK cells and by decreased serum levels of IL-7 and sCD25. MDD patients aged ⩾ 28 years additionally exhibited decreased percentages of CD4(+)CD25(high)FoxP3(+) T regulatory cells, next to signs of the above described partial T cell defects. Natural T regulatory cells were inversely associated with the pro-inflammatory state of the monocytes (r=-.311; p=.034) that characterized this patient subgroup. CONCLUSIONS Deficiencies of the NK and T (regulatory) cell system and inflammatory monocyte immune activation co-occur as partly interrelated phenomena within the same MDD patients.

Association of vital exhaustion and depressive symptoms with changes in fibrin D-dimer to acute psychosocial stress

OBJECTIVE Vital exhaustion and depression are psychosocial risk factors of coronary artery disease. A hypercoagulable state in response to acute psychosocial stress contributes to atherothrombotic events. We aimed to investigate the hypothesis that vital exhaustion and depression correlate with stress-induced changes in the hypercoagulability marker D-dimer. METHODS Thirty-eight healthy and nonsmoking school teachers (mean age 50+/-8 years, 55% women) completed the nine-item Maastricht Vital Exhaustion Questionnaire and the seven-item depression subscale of the Hospital Anxiety and Depression Scale. Within 1 week, subjects twice underwent the Trier Social Stress Test (i.e., preparation phase, mock job interview, and mental arithmetic that totaled 13 min). Plasma D-dimer levels were determined at five time points during the protocol. RESULTS Vital exhaustion (P=.022; eta(2)=.080) and depressive symptoms (P=.011; eta(2)=.090) were associated with stress-induced changes in D-dimer levels over time controlling for sex and age. Elevated levels of vital exhaustion (r=-.46, P=.005) and of depression (r=-.51, P=.002) correlated with reduced D-dimer increase from pre-stress to immediately post-stress. Also, elevated vital exhaustion (r=.34, P=.044) and depression (r=.41, P=.013) were associated with increase (i.e., attenuated recovery) of D-dimer levels between 20 and 45 min post-stress. Controlling for stress hormone and blood pressure reactivity did not substantially alter these results. CONCLUSION The findings suggest an attenuated immediate D-dimer stress response and delayed recovery of D-dimer levels post-stress with elevated vital exhaustion and depressive symptoms. In particular, the prolonged hypercoagulability after stress cessation might contribute to the atherothrombotic risk previously observed with vital exhaustion and depression, even at subclinical levels.

Clinical characteristics of inflammation-associated depression: Monocyte gene expression is age-related in major depressive disorder

Increased inflammatory activation might only be present in a subgroup of depressed individuals in which immune processes are especially relevant to disease development. We aimed to analyze demographic, depression, and trauma characteristics of major depressive disorder (MDD) patients with regard to inflammatory monocyte gene expression. Fifty-six naturalistically treated MDD patients (32 ± 12 years) and 57 healthy controls (HC; 31 ± 11 years) were analyzed by the Inventory of Depressive Symptomatology (IDS) and by the Childhood Trauma Questionnaire (CTQ). We determined the expression of 38 inflammatory and immune activation genes including the glucocorticoid receptor (GR)α and GRβ genes in purified CD14(+) monocytes using quantitative-polymerase chain reaction (RT-qPCR). Monocyte gene expression was age-dependent, particularly in MDD patients. Increased monocyte gene expression and decreased GRα/β ratio were only present in MDD patients aged ⩾ 28 years. Post hoc analyses of monocyte immune activation in patients <28 years showed two subgroups: a subgroup with a severe course of depression (recurrent type, onset <15 years) - additionally characterized by panic/arousal symptoms and childhood trauma - that had a monocyte gene expression similar to HC, and a second subgroup with a milder course of the disorder (73% first episode depression, onset ⩾15 years) - additionally characterized by the absence of panic symptoms - that exhibited a strongly reduced inflammatory monocyte activation compared to HC. In conclusion, monocyte immune activation was not uniformly raised in MDD patients but was increased only in patients of 28 years and older.