Elsevier

Physiology & Behavior

Volume 199, 1 February 2019, Pages 292-299
Physiology & Behavior

Reduced professional efficacy is associated with a blunted salivary alpha-amylase awakening response

https://doi.org/10.1016/j.physbeh.2018.11.038Get rights and content

Highlights

  • Reductions in professional efficacy are associated with a ‘flattened’ sAA-AR.

  • Reduced professional efficacy mediates relationship between job stress and sAA-AR.

  • The sAA-AR may be a useful indicator of burnout.

  • Perceived stress or physiology in isolation is not as useful as assessing both.

Abstract

The job demands-resources model (JD-R) has shown an ability to predict worker engagement and exhaustion, yet to our knowledge, research has not been conducted that assesses the JD-R model with physiological indicators of chronic stress and burnout. Using the JD-R model, we assessed if occupational stress and burnout were related to dysregulated cortisol and salivary alpha-amylase awakening responses (sAA-AR). Professional apprentice jockeys comprising of males (n = 14) and females (n = 18) provided morning saliva samples and completed self-report measures relating to job demands and resources, burnout, and perceived mental and physical health. Data was collected at two time points coinciding with naturally occurring ‘low’ and ‘high’ stress periods during the racing calendar. The jockeys reported good physical and mental health but had elevated levels of the burnout subtypes cynicism and exhaustion. Regression analyses suggested that those jockeys presenting with reduced professional efficacy in the high stress period produced a ‘flattened’ sAA-AR indicative of reduced autonomic nervous system (ANS) arousal, which has been associated with burnout. Further, decreases in professional efficacy explained the relationship between increased workplace stress and decreased ANS activity in the high stress period. Our findings suggest that assessments of psychological stress or physiology in isolation are not as useful as looking at both in combination, and extend previous findings on the sAA-AR.

Introduction

The relationship of discrete measures of the burnout syndrome with indices of stress physiology is not well understood [1]. The two primary neuroendocrine response systems activated when faced with a perceived threat are the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary (SAM) system [2,3]. Neuroendocrine stress and burnout research has typically focused on HPA axis reactivity as most researchers consider salivary cortisol levels a reliable indicator of HPA axis activity and adaptation to stress [[4], [5], [6]]. However, less is known about the surrogate autonomic nervous system (ANS) marker, salivary alpha-amylase (sAA) [7]. Elevated levels of sAA concentrations reflect ANS activity in response to stress and involve activation of both the parasympathetic and sympathetic nerves [[8], [9], [10]]. Studies have demonstrated that an increase in sAA levels can be expected in response to acute stress stimuli when autonomic activation is high in a range of contexts [9,11,12]. However, only a small number of studies have investigated associations between the sAA awakening response (sAA-AR) and chronic work stress. These studies have produced inconsistent results including finding perceived work stress to be associated with a less steep sAA-AR among educators [13], an increase in sAA levels 30 min after awakening among health care professionals reporting high job strain [14], while others have reported no relationship between workplace stress and sAA in a group of nurses [15].

Based on the available evidence, chronic stress may impair the functioning of either the SAM or the HPA axis, or the interplay between the two systems [16]. As sAA is less likely to be influenced by variables such as age, habitual smoking, coffee consumption, and oral contraception than cortisol [15], the sAA-AR may be a more reliable indicator of psychological stress. This premise, however, requires empirical enquiry. Others have suggested that the sAA -AR measured concurrently with the cortisol awakening response (CAR) may potentially provide a better explanation of the endocrine stress response than either biomarker considered in isolation [17]. The diurnal pattern of sAA-AR is inversely related with the CAR, and typically, sAA levels decrease upon waking and then steadily rise over the course of the day [18,19]. The sAA-AR has been shown to be reactive to stress in a range of contexts [20], including the workplace [13,21]. In one of the few studies comparing the CAR and the sAA-AR within the context of occupational stress, higher states of depersonalization and ambition were associated with a blunted CAR among a group of teachers reporting chronic stress and burnout, and similarly, higher ambition and perceived stress were associated with a less steep sAA-AR [13].

The job demands-resources model (JD-R) asserts that although every occupation has its own set of specific risk factors associated with workplace stress, these factors can be classified into two general categories: job demands (e.g., high work pressure, unfavourable physical environment, emotionally demanding interactions with clients) and job resources (e.g., salary, job security, career prospects, role clarity, skill variety, autonomy) [22,23]. According to JD-R theory, job demands are related with adverse well-being and high resources are associated with improved motivation and work engagement. In this study, we focus on the interaction hypothesis. Specifically, we assess the interaction hypothesis that stress and employee burnout occur when job demands are high and job resources are low, often resulting in health impairment [22,24]. However, to our knowledge, the JD-R model has yet to consider the association of job stress with physiological indices of stress. The JD-R model is more flexible than other occupational stress models in its approach to conceptualizing workplace stress, and lends itself to being applied to various occupational settings, potentially even professional athletes [25,26].

When coupled with insufficient recovery, chronic exposure to occupational stressors can result in burnout [[27], [28], [29]], which is typically characterized by exhaustion, cynicism, and reduced professional efficacy [28]. This three-dimensional theoretical construct continues to be the predominant one in the burnout field [28] and although empirically supported by cross-sectional studies, fewer researchers have utilized a longitudinal design [[30], [31], [32]]. While much of the research originally concentrated on people-oriented, human service occupations (e.g., health care professionals, educators), the concept of burnout has also been broadened to apply to non-human service professions (e.g., assembly line workers, air traffic controllers, military personnel) [23]. However, burnout is not solely related to work as it may ensue after prolonged exposure to any situation that may be emotionally demanding e.g., athlete (amateur) burnout [33], parental burnout [34], and caregiver burnout [35]. Although burnout is a serious condition among athletes [36] and is associated with performance impairment, reduced enjoyment, depressed mood, and premature retirement from the sport, athletes have rarely been the focus of investigations assessing occupational stress and burnout.

In this study, we focused on apprentice horse jockeys as they experience high levels of work stress [37], and report chronic stressors including maintaining a consistent weight and working long hours [38]. We examined the relationships between occupational stress, burnout, and physiology across two time points reported by jockeys to represent naturally occurring ‘low’ and ‘high’ stress periods during the racing calendar [39], and assessed if individual changes in occupational stress perceptions were associated with indicators of dysregulated stress physiology across the low and high stress periods. Our previous focus group interviews with these jockeys [39] revealed the spring months as being perceived as more stressful than the winter months due to work and financial opportunities associated with the racing calendar. Essentially, the spring months are when the most prestigious races take place and it is difficult for apprentices to ‘find a ride’, and many are restricted to non-competition work (e.g., horse handling, track work). However, after this period, when the senior riders take breaks, more opportunities become available. We expected that high stress periods would correspond with poorer perceptions of stress and health (physical and mental), and with dysregulated stress physiology. Finally, we anticipated that high workplace stress and high self-reported burnout would be related to dysregulated physiological reactivity.

Section snippets

Participants

Full-time professional Australian apprentice flat-racing jockeys (aged 15–24 years; N = 32) provided data at two time points (low and high stress periods). Both apprentice and senior jockeys in Australia are considered ‘professional’ as they are licensed, full-time paid employees, and racing is their primary occupation. The sample comprised 14 males (M age = 18.1, SD = 1.5) and 18 females (M age = 19.9, SD = 2.3), representing 64% of all apprentice jockeys within the region. Participants were

Normative data

Normative comparisons revealed that our sample reported significantly higher scores for the cynicism and exhaustion scales during the high stress period (Table 1). When comparing our sample's scores on these same scales between the low and high stress time points, the sample reported significantly higher scores during the high stress period. Perceived levels of job demands and job resources, however, did not differ between the two time-points, suggesting our sample perceived that similar levels

Discussion

We investigated the associations between self-reported job stress, burnout, health, and pre-clinical stress-related biomarkers across two time points coinciding with naturally occurring ‘low’ and ‘high’ stress periods. Our main findings from the hierarchical regressions suggest that those jockeys presenting with reduced professional efficacy in the high stress period produced a ‘flattened’ sAA-AR indicative of reduced sympathetic arousal, which has been associated with burnout. Mediation

Conclusions

The present study would appear to be the first study to assess the JD-R model using physiological indices of stress, potentially an important step in the development of this model. Additionally, our findings suggest that assessments of psychological stress or physiology in isolation are not as useful as looking at both in combination. Measurements of the sAA-AR as a surrogate biomarker of ANS dysregulation may prove to be an important tool in identifying both the magnitude of the burnout

Source of funding and conflicts of interest

KL was supported by an Australian Government Research Training Program Scholarship. This research was supported from funding from the Sport, Exercise and Rehabilitation Research Focus Area, La Trobe University. The authors report no conflict of interest.

References (66)

  • U.M. Nater et al.

    Determinants of the diurnal course of salivary alpha-amylase

    Psychoneuroendocrinology

    (2007)
  • J.R. Halbesleben et al.

    Burnout in organizational life

    J. Manag.

    (2004)
  • G.M. Alarcon

    A meta-analysis of burnout with job demands, resources, and attitudes

    J. Vocat. Behav.

    (2011)
  • H. Gustafsson et al.

    A qualitative analysis of burnout in elite Swedish athletes

    Psychol. Sport Exerc.

    (2008)
  • K.A. Landolt et al.

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

    Psychoneuroendocrinology

    (2017)
  • J.C. Pruessner et al.

    Free cortisol levels after awakening: a reliable biological marker for the assessment of adrenocortical activity

    Life Sci.

    (1997)
  • G. Vilagut et al.

    The mental component of the short-form 12 health survey (SF-12) as a measure of depressive disorders in the general population: results with three alternative scoring methods

    Value Health

    (2013)
  • T. Stalder et al.

    Assessment of the cortisol awakening response: expert consensus guidelines

    Psychoneuroendocrinology

    (2016)
  • A. Marchand et al.

    Burnout symptom sub-types and cortisol profiles: What's burning most?

    Psychoneuroendocrinology

    (2014)
  • M.V. Thoma et al.

    Altered salivary alpha-amylase awakening response in Bosnian War refugees with posttraumatic stress disorder

    Psychoneuroendocrinology

    (2012)
  • J. Strahler et al.

    Aging diurnal rhythms and chronic stress: distinct alteration of diurnal rhythmicity of salivary α-amylase and cortisol

    Biol. Psychol.

    (2010)
  • B.M. Kudielka et al.

    Why do we respond so differently? Reviewing determinants of human salivary cortisol responses to challenge

    Psychoneuroendocrinology

    (2009)
  • T. Chandola et al.

    Psychophysiological biomarkers of workplace stressors

    Neurosci. Biobehav. Rev.

    (2010)
  • A. Steptoe et al.

    Stress and cardiovascular disease

    Nat. Rev. Cardiol.

    (2012)
  • A. Steptoe et al.

    Stress and cardiovascular disease: an update on current knowledge

    Annu. Rev. Public Health

    (2013)
  • Clow A, Hucklebridge F, Stalder T, Evans P, Thorn L. The cortisol awakening response: more than a measure of HPA axis...
  • R.T. Chatterton et al.

    Salivary α-amylase as a measure of endogenous adrenergic activity

    Clin. Physiol.

    (1996)
  • N. Iizuka et al.

    Salivary alpha-amylase activity and stress in Japan air self-defense force cargo pilots involved in Iraq reconstruction

    Am. J. Hum. Biol.

    (2012)
  • K. Karhula et al.

    Association of job strain with cortisol and alpha-amylase among shift-working health care professionals in laboratory and field

    Biol. Res. Nurs.

    (2016)
  • A.M. Bauer et al.

    Associations between physiological reactivity and children's behavior: advantages of a multisystem approach

    J. Dev. Behav. Pediatr.

    (2002)
  • D.S. Koh et al.

    The use of salivary biomarkers in occupational and environmental medicine

    Occup. Environ. Med.

    (2007)
  • N. Rohleder et al.

    The psychosocial stress-induced increase in salivary alpha-amylase is independent of saliva flow rate

    Psychophysiology

    (2006)
  • P. Eddy et al.

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

    Stress

    (2018)
  • Cited by (0)

    View full text