An experimental study of the job demand-control model with measures of heart rate variability and salivary alpha-amylase: Evidence of increased stress responses to increased break autonomy

Severity of depressive symptoms moderates the sympathoinhibitory effect of local skin warming following exposure to a social stressor

Depression is the leading cause of disease burden globally. Existing antidepressant treatments that target the central nervous system have limited efficacy and come at the cost of significant side effects. Thus, there is growing interest in novel therapeutic interventions for the prevention and treatment of depression, including interventions that target interoceptive signaling. The thermosensory system may hold particular promise, given evidence that depression is associated with impairments in thermosensory functioning, and that whole-body hyperthermia produces an antidepressant effect in patients with major depressive disorder. In this study, we investigated whether the severity of depressive symptoms in a non-clinical population moderated the effect of local skin warming on subjective and physiological stress responses following exposure to an acute social stressor. Following exposure to the stressor, participants (N = 90) rested their arm on a heat blanket that was either turned on (local skin warming condition) or left off (control condition). We demonstrate that local skin warming increased fingertip temperature, a marker of reduced sympathetic nervous system activity, but only for participants with high levels of depressive symptoms. While local skin warming also inhibited salivary alpha amylase, severity of depressive symptoms did not moderate this effect, and no effect was found for electrodermal activity. These data highlight the importance of incorporating peripheral physiology in our conceptualization of the pathophysiology of depression and show that changes in sympathetic nervous system activity may underpin the antidepressant effect of warm stimuli.

The association between study conditions and hair cortisol in medical students in Germany - a cross-sectional study

BACKGROUND

Medical students often experience high levels of stress due to adverse study conditions, which may have adverse health consequences. Hair cortisol concentration (HCC) has been described as a physiological marker for chronic stress and might thus help to identify students under stress and examine the study conditions being responsible for long-term physiological stress responses. This study therefore investigated the association between study conditions and HCC in a sample of medical students.

METHODS

Fifty-five students from a medical school in Germany completed a paper-based questionnaire and had hair samples collected between May 2020 and July 2021. Study conditions were assessed with student versions of questionnaires based on the Job-Demand-Control-Support model (StrukStud, 25 items) and Effort-Reward Imbalance model (Student ERI, nine items). HCC of two centimeters closest to the scalp were determined by a cortisol luminescence immunoassay. Linear multiple regression analyses were performed to examine associations between study conditions and HCC.

RESULTS

Demands (B = 0.23, p = 0.002), effort (B = 0.12, p = 0.029) and the effort-reward-ratio (B = 0.28, p = 0.007) were positively associated with HCC in separate regression analyses, adjusted for age and sex. Only the association between demands and HCC remained significant when all components of the respective questionnaire were considered in the same model (B = 0.22, p = 0.003).

CONCLUSION

The results suggest that adverse study conditions may be associated with activation of the hypothalamic-pituitary-adrenal axis stress response as reflected by increased HCC. Longitudinal research is needed to confirm these cross-sectional results and examine effects of more prolonged stress due to adverse study conditions.

Autonomy in the context of cognitive demands-is the resource becoming a stressor?

OBJECTIVE

Autonomy is often associated with positive linear effects on health whereas non-linear correlations have received only sporadic attention. Assuming that the use of autonomy also represents a cognitive demand, this study examines whether health effects of autonomy change depending on further cognitive demands and whether curvilinear relationships can be identified.

METHODS

A survey was carried out in three SMEs with established work analysis questionnaires. 197 Employees were classified into groups with high and with low cognitive demands by means of a two-step cluster analysis. This was modeled as moderator together with curvilinear effects of autonomy in regression analyses.

RESULTS

Curvilinear associations were found for emotional exhaustion, cynicism, and anxiety. They were strongest for anxiety. No moderating effects of cognitive demands and no consistently significant modeled relations were found.

CONCLUSION

The results confirm that autonomy has a positive influence on the health of employees. However, autonomy should not be seen as an isolated resource but embedded in the organizational and societal context.

Psychosocial working conditions and chronic low-grade inflammation in geriatric care professionals: A cross-sectional study

Background

Chronic low-grade inflammation has been suggested as a key factor in the association between stress exposure and long-term health. Care work is recognized as a profession with a high degree of job stress and health risks. However, for care professionals, the study base on inflammatory activity due to adverse working conditions is limited.

Objective

The aim of this study was to explore associations between self-reported psychosocial working conditions and care professionals’ biomarkers of systemic low-grade inflammation.

Methods

N = 140 geriatric care professionals (79.3% females, mean age = 44.1 years) of six care facilities were enrolled in a cross-sectional study consisting of standardized medical examinations and employee surveys. Standardized questionnaires were used for evaluation of psychosocial work characteristics (work overload, job autonomy, social support) based on Karasek’s job strain model. Blood samples were drawn for two biomarkers of inflammatory activity: C-reactive protein (CRP) and leukocyte count. Analyses comprised uni- and multivariate logistic and linear regression analyses.

Results

We determined a proportion of 5.4% of care professionals with increased low-grade inflammation. We further observed a relationship between job autonomy and CRP, such that reports of high job autonomy were associated with increased levels of CRP (adjusted OR = 4.10, 95% CI [1.10, 15.26], p = .035), which was robust in additional analyses on further potential confounders. No significant associations with participants’ leukocyte numbers were found.

Conclusions

This exploratory study contributes to the research base on links between workplace stress and ensuing illness in care professionals. Our findings may help to identify risk and protective factors of the work environment for chronic low-grade inflammation. The results require further scrutiny, and future prospective studies on associations of psychosocial working conditions, low-grade inflammation and long-term health outcomes in care professionals are needed.

The effects of emotional trait factors on simulated flight performance under an acute psychological stress situation

Objective. Pilots are commonly exposed to some sources of emotional and cognitive stressors, especially for flight cadets, which have an important influence on flight safety. The present study aimed to study the relationship between emotional trait factors, emotional state, mental workload and simulated flight performance (SFP) under an acute psychological stress situation. Methods. Fifty-five undergraduates were included in the study. The Wong and Law emotional intelligence scale (WLEIS), state-trait anxiety inventory (STAI), stress rating questionnaire (SRQ) and National Aeronautics and Space Administration task load index (NASA-TLX) were used as data collection tools. Nine hours of simulated flight training were conducted in a simulator of the Type-6 Primary Trainer (Aviation University Air Force, China). The simulated flight assessment was taken as the acute psychological stressor. Results. SFP was negatively correlated with tensity and state anxiety. Emotional intelligence (EI) indirectly affected the SFP mediated by emotional state and workload, and emotional state had a mediating effect on the relationship between trait anxiety and SFP. Conclusions. The findings indicated that emotional trait factors (EI and trait anxiety) may indirectly affect SFP under an acute psychological stress situation, and emotional state (tensity and state anxiety) and mental workload played an important mediating role.

Empathy and job resources buffer the effect of higher job demands on increased salivary alpha amylase awakening responses in direct-care workers

The job demands-resources (JD-R) model has rarely been used in conjunction with physiological indicators of stress and ill-health. This study explored the associations between the JD-R model and physiological indicators of the stress response, while considering potential moderators of this relationship. Across 2 timepoints (summer-winter) direct-care workers completed questionnaires assessing job demands, job resources, empathy and self-efficacy, and provided morning saliva samples to assess physiological indices of stress and ill-health. Changes in job resources and empathy were positively correlated with changes in the cortisol awakening response (CAR). Further, changes in both job resources and empathy independently buffered the impact of higher job demands on increased salivary alpha amylase awakening response (sAA-AR) concentrations. These findings suggest that despite increased job demands, the sAA-AR decreased for direct-care workers that had perceived high job resources or who reported higher empathy. Potentially, job resources and empathy may act as a protective factor against the development of poor health associated with workplace stress.

Fatores de Risco e Riscos Psicossociais no Trabalho: Definição e Implicações

Resumo O objetivo deste artigo teórico é analisar os conceitos de fatores de risco e riscos psicossociais no trabalho, bem como discuti-los a partir de duas perspectivas teóricas proeminentes no campo: o Modelo Demanda-Controle e a Psicodinâmica do Trabalho. Além das definições, são apresentadas as relações entre antecessores - fatores de risco, e consequentes - riscos psicossociais, e as implicações teóricas e práticas decorrentes da definição mais acurada dos termos. As conclusões apresentadas apontam para importância de delimitação conceitual entre fatores de risco e riscos psicossociais no trabalho como passo indispensável para o desenvolvimento de estratégias eficazes de avaliação e intervenção nos contextos de trabalho, principalmente pela adoção de uma postura preventiva com foco na identificação e controle dos fatores de risco prioritariamente.

Methods in Experimental Work Break Research: A Scoping Review

The number of studies on work breaks and the importance of this subject is growing rapidly, with research showing that work breaks increase employees’ wellbeing and performance and workplace safety. However, comparing the results of work break research is difficult since the study designs and methods are heterogeneous and there is no standard theoretical model for work breaks. Based on a systematic literature search, this scoping review included a total of 93 studies on experimental work break research conducted over the last 30 years. This scoping review provides a first structured evaluation regarding the underlying theoretical framework, the variables investigated, and the measurement methods applied. Studies using a combination of measurement methods from the categories “self-report measures,” “performance measures,” and “physiological measures” are most common and to be preferred in work break research. This overview supplies important information for ergonomics researchers allowing them to design work break studies with a more structured and stronger theory-based approach. A standard theoretical model for work breaks is needed in order to further increase the comparability of studies in the field of experimental work break research in the future.

Positive verbal feedback about task performance is related with adaptive physiological responses: An experimental study of the effort-reward imbalance stress model

Effort-reward imbalance in the workplace has been related with poor mental and physical health and a variety of negative organisational outcomes including increased rates of absenteeism, presentism, and job turnover, but the model has rarely been assessed using experimental designs. Female participants (N = 90) were randomly assigned to positive verbal feedback and no verbal feedback conditions. Within a simulated office environment, all participants were under time-pressure to successfully complete computer-based tasks in order to gain remuneration. Positive verbal feedback about task performance was provided to improve the aspect of 'esteem reward' (while keeping effort constant) using a mixed within-between subjects design. Psychological, behavioural (task performance), and physiological (heart rate variability, salivary alpha amylase) measures assessed the impact of the positive verbal feedback. Participants receiving the esteem manipulation did not self-report increased rewards, but performed moderately better on the task, and had more adaptive physiological reactivity in the high reward versus the standard condition. Similar to recent research our findings highlight the importance of concurrent assessments of both self-reports and physiological measures of stress, and suggest that positive verbal feedback about work performance can elicit adaptive physiological responses and may also positively influence task efficacy.

An online mindfulness-based program is effective in improving affect, over-commitment, optimism and mucosal immunity

Previous studies have demonstrated mindfulness-based programs are effective in reducing workplace stress; however, few have investigated the effectiveness of online mindfulness-based programs. Physiological measures are also underutilised when examining the efficacy of these programs. Therefore, we assessed the efficacy of an online mindfulness-based program on both short-term and more enduring aspects of psychological and physiological measures of stress and ill-health. Participants (N = 22) completed an 8-week online mindfulness-based program. Immediately before and after a mindfulness session, participants completed questionnaires to assess the short-term effects on mood and state anxiety and provided saliva samples to assess salivary alpha amylase (sAA) concentrations. Additionally, pre and post the 8-week intervention, participants completed questionnaires assessing workplace stress, over-commitment, work engagement, dispositional mindfulness and personal resources. Saliva samples were collected to measure the cortisol awakening response, sAA awakening response and secretory immunoglobulin A (sIgA). Our findings demonstrate that online mindfulness-based programs induce short-term improvements in fatigue and anxiety in employees. Additionally, we also report a decrease in over-commitment and increases in optimism and mucosal immunity (sIgA) following the program.

The salivary alpha amylase awakening response is related to over-commitment

We assessed the relationship between physiological and psychological measures of workplace stress as measured by the effort-reward imbalance (ERI) model, with a seldom studied sample of owner-operator dairy farmers. Dairy farmers (N = 74) self-reported ERI, over-commitment (OC), dedication, and health then provided awakening saliva samples that were used to calculate the salivary alpha amylase awakening response (sAA-AR), cortisol awakening response (CAR), and salivary immunoglobulin A (sIgA) level. ERI, OC, and dedication levels were not related with sIgA or the CAR, but more over-committed farmers had a less pronounced sAA-AR. OC was more associated than ERI with the physiological indicators of stress, potentially due to the owner-operator sample used in this investigation. The suitability of sAA as a viable physiological measure of autonomic nervous system activity has been debated, but our findings promote its inclusion in future occupational stress research.

Chronic work stress and decreased vagal tone impairs decision making and reaction time in jockeys

The inverse relationship between acute stress and decision-making is well documented, but few studies have investigated the impact of chronic stress. Jockeys work exhaustive schedules and have extremely dangerous occupations, with safe performance requiring quick reaction time and accurate decision-making. We used the effort reward imbalance (ERI) occupational stress model to assess the relationship of work stress with indices of stress physiology and decision-making and reaction time. Jockeys (N=32) completed computerised cognitive tasks (Cogstate) on two occasions; September and November (naturally occurring lower and higher stress periods), either side of an acute stress test. Higher ERI was correlated with the cortisol awakening responses (high stress r=-0.37; low stress r=0.36), and with decrements in decision-making comparable to having a blood alcohol concentration of 0.08 in the high stress period (p<0.001) The LF/HF ratio of heart rate variability impacted the association of ERI with decision-making. Potentially, this may be attributed to a 'tipping point' whereby the higher ERI reported by jockeys in the high stress period decreases vagal tone, which may contribute to reduced decision-making abilities.

An experimental examination of the effort-reward imbalance model of occupational stress: Increased financial reward is related to reduced stress physiology

Effort-reward imbalance in the workplace is linked to a variety of negative health and organisational outcomes, but it has rarely been assessed experimentally. We manipulated reward (while keeping effort constant) in a within-subjects design with female participants (N=60) who were randomly assigned to high and standard reward conditions within a simulated office environment. Self-report, behavioural (task performance), and physiological (heart rate variability, salivary alpha amylase) measures assessed the impact of increased financial reward. Participants reported increased perceptions of reward, performed moderately better on the task, and were less physiologically reactive in the high reward versus the standard condition. These findings highlight the importance of assessing both subjective self-reports of stress together with objective physiological measures of stress, and suggest that increasing monetary rewards has the potential to decrease stress physiological reactivity, and in turn, reduce the risk of ill-health in employees, and may also positively influence task efficacy.

Salivary cortisol and α-amylase: subclinical indicators of stress as cardiometabolic risk

Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary cortisol and α-amylase, produced respectively by the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary (SAM) system during stress response, are still not included in the routine evaluation of CV risk and require additional and definitive validation. Therefore, this article overviews studies published between 2010 and 2015, in which salivary cortisol and α-amylase were measured as stress biomarkers to examine their associations with CV/CMR (cardiometabolic risk) clinical and subclinical indicators. A comprehensive search of PubMed, Web of Science and Scopus electronic databases was performed, and 54 key articles related to the use of salivary cortisol and α-amylase as subclinical indicators of stress and CV/CMR factors, including studies that emphasized methodological biases that could influence the accuracy of study outcomes, were ultimately identified. Overall, the biological impact of stress measured by salivary cortisol and α-amylase was associated with CV/CMR factors. Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases and especially to describe the mechanisms by which stress potentially contributes to the pathogenesis and outcomes of CV diseases.

The effects of autonomy support on salivary alpha-amylase: The role of individual differences

The empirical evidence for the relationship between autonomy-supportive environments and physiological stress is inconsistent. Whereas some studies report a decrease in stress in autonomy-supportive environments, other studies show a negative effect of autonomy on physiological stress. As previous research has not considered individual differences within this relationship, the present research aims to close this empirical gap by proposing that an implicit autonomy disposition, which is defined as a dispositional preference for self-determination, serves as a moderator. In an experiment, we tested whether the autonomy disposition moderates the effect of different teaching styles (controlling, autonomy-supportive, and neutral) on the acute physiological stress response (salivary alpha-amylase) in adolescents (N=69). The study revealed that participants with a high implicit autonomy disposition displayed lower salivary alpha-amylase responses when exposed to autonomy-supportive vignettes compared to when they were exposed to controlling or neutral teaching styles. The opposite pattern was found in students with a low implicit autonomy disposition. The results illustrate that experimentally induced variations in autonomy support lead to different physiological stress responses, depending on individual differences in the implicit autonomy disposition.

Beyond catecholamines: Measuring autonomic responses to psychosocial context

Despite longstanding interest among human biologists in autonomic responses to socioecological context or culture change, the adoption of autonomic measures has been limited by methodological challenges. Catecholamine secretion is the most direct measure, but not all study designs are amenable to urinary sampling, and blood pressure lacks specificity to the parasympathetic or sympathetic division of the autonomic nervous system. This article reviews three alternative approaches for measuring autonomic responses: salivary α-amylase as a nonspecific autonomic marker, respiratory sinus arrhythmia as a specific parasympathetic marker, and the pre-ejection period as a specific sympathetic marker. Study design considerations are discussed in detail, including ambulatory sampling protocols that permit the evaluation of autonomic responses to everyday life. Researchers interested in how culture and social experience "get under the skin," as well as those concerned with the evolution of social engagement, can benefit from these well-validated biomarkers that are nevertheless relatively novel in human biology. Am. J. Hum. Biol. 28:309-317, 2016. © 2015 Wiley Periodicals, Inc.