Exhaustion measured by the SF-36 vitality scale is associated with a flattened diurnal cortisol profile

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Summary

The possible association between stress-related exhaustion and reduced activity in the hypothalamo–pituitary–adrenal (HPA) axis is increasingly in focus. The aim of the present study was to examine whether exhaustion measured in a non-patient population is associated with alterations in diurnal cortisol profile. The study population included 78 working individuals. The study group was dichotomised into exhausted and non-exhausted groups by means of the SF-36 vitality scale. Salivary cortisol was measured at three times during 1 workday: at awakening, 30 min after awakening, and in the evening. The results showed that diurnal cortisol variation was significantly reduced in exhausted individuals. The difference in cortisol variation was mainly due to lowered morning cortisol in the exhausted group. Differences in cortisol levels at each sampling time or in mean diurnal output of cortisol were not statistically significant. The results would support the notion that exhaustion is associated with HPA axis hypoactivity as assessed by salivary cortisol. Furthermore, the SF-36 vitality provides a measure of exhaustion that may be useful in epidemiological studies in order to explore long-term health effects of stress-related exhaustion.

Introduction

Exhaustion can be described as a condition characterized by fatigue and loss of strength or vitality. The possible association between exhaustion and reduced activity in the hypothalamo–pituitary–adrenal (HPA) axis is increasingly discussed (Nicolson and van Diest, 2000; Raison and Miller, 2003; Fries et al., 2005). This notion is mainly derived from studies concerning different clinically established disorders exhibiting hypocortisolaemic features (e.g. posttraumatic stress disorder, chronic fatigue syndrome, fibromyalgia, atypical depression) in which fatigue constitutes a prominent characteristic (Yehuda et al., 1991; Demitrack and Crofford, 1998; Gold and Chrousos, 1999). The aetiology of the decreased HPA activity in hypocortisolaemic disorders has been disputed (Cleare, 2004a, Cleare, 2004b), but since disturbances in the HPA axis are intimately associated with physiological stress response systems, HPA hypoactivity is frequently considered a possible feature of chronic stress (Demitrack and Crofford, 1998; McEwen, 1998; Heim et al., 2000). This view thus contrasts with the more traditional view that stress is characterized by an increased activation of the HPA axis, and it is hypothesised that HPA hyporesponsiveness would constitute a later phase in the chronic stress process, subsequent to an initial period of stress-induced HPA hyperactivity (McEwen, 1998; Fries et al., 2005).

In normal (non-clinical) populations, cortisol patterns indicating hypoactivity in the HPA axis have been observed in association with chronic stress (e.g. Caplan et al., 1979; Goenjian et al., 1996; Adam and Gunnar, 2001; Ranjit et al., 2005). In a study of medically healthy individuals it was shown that cortisol levels that were substantially suppressed due to severe chronic stress returned to normal after termination of the stressful period (Zarkovic et al., 2003). Chronic stress thus seems to exert a “direct” effect on the HPA axis in reducing its activity, i.e. without being mediated by disease. In these studies the potential link between exhaustion and cortisol was not considered. Most research concerning this relationship has been performed by means of using measures of “burnout”—which include exhaustion as one of several dimensions—but the summarised findings of cortisol in burnout have not yet been conclusive (Mommersteeg et al., 2006). Moreover, the measure of “vital exhaustion”, developed for prediction of myocardial infarction (Appels et al., 1987), has been shown to correlate with attenuated cortisol response and reduced diurnal cortisol variation (Kristenson et al., 1998; Sjögren et al., 2006). It should be noted that the construct of vital exhaustion contains dimensions of both exhaustion and depression (Appels, 1980; Appels et al., 2000; Prescott et al., 2003; McGowan et al., 2004) and cortisol levels associated with vital exhaustion can therefore be regarded as a reflection of a combination of physiological patterns in these two conditions. In a study of particular interest concerning cortisol patterns in exhaustion, the vital exhaustion measurement was used in order to screen for exhaustion after which depressed participants were excluded from the study (Nicolson and van Diest, 2000), thereby ensuring that the reported findings concern exhaustion and not depression. The study was performed on a sample of healthy working males, and a tendency towards overall lower levels of cortisol was found in exhausted individuals compared with controls.

The purpose of the present study was to further explore cortisol patterns in exhaustion as assessed in a non-patient population. For the assessment of exhaustion the SF-36 vitality scale was utilised. Exhaustion measured by this scale has been shown to be differentiable from measures of depression and anxiety (Lindeberg et al., 2006), which would seem valuable considering evidence of increased HPA activity and elevated cortisol levels in depression and anxiety disorders (Gillespie and Nemeroff, 2005; Abelson et al., 2007).

The study objective was to elucidate whether exhaustion measured by the SF-36 vitality scale in a working population was associated with differences in salivary cortisol concentrations and in the diurnal variation of salivary cortisol (cortisol variability). Our primary hypothesis was to find lowered cortisol variability and suppressed concentrations of cortisol (indicating HPA axis hypoactivity) in exhausted individuals compared with non-exhausted.

Section snippets

Participants and design

The study sample consisted of 78 individuals, 57 females and 21 males, who participated in a follow-up assessment of a cohort study concerning possible predictors of work-related ill-health. The initial cohort (N=437) was identified in the year 2001 and was recruited from five different work-sites including manual and non-manual employees (Hansen et al., 2006). The work-sites were recruited on the basis of possible high workload and were identified in collaboration with the local Labour

Results

Twenty respondents (26%) scored 16 or above on the inverted SF-36 vitality score and were thereby designated as belonging to the exhausted group. Fifty-eight respondents scored below 16 and were thus defined as non-exhausted. Descriptive characteristics of the exhausted and non-exhausted groups are shown in Table 1. Age was slightly lower and BMI was slightly higher in the exhausted group. Daily smoking was fairly evenly distributed between groups, and saliva cortisol was sampled at similar

Discussion

The results of this study showed that exhausted individuals exhibited a flattened diurnal cortisol profile compared with non-exhausted. The flattened profile was due to lowered cortisol levels in the morning whereas evening cortisol did not differ between the groups. Overall cortisol levels thus tended towards being lower in exhausted individuals but these differences were not statistically significant.

A recent meta-analytic review (Miller et al., 2007) revealed that low morning cortisol and

Role of the funding source

Funding for this study was provided by The Swedish Research Council and Swedish Council for Working Life and Social Research. The funding sources had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.

Conflict of interest

We declare that we have no conflicts of interest.

Acknowledgements

We thank The Swedish Research Council and The Swedish Council for Working Life and Social Research for financial support.

References (47)

  • P.M. Mommersteeg et al.

    Clinical burnout is not reflected in the cortisol awakening response, the day-curve or the response to a low-dose dexamethasone suppression test

    Psychoneuroendocrinology

    (2006)
  • N.A. Nicolson et al.

    Salivary cortisol patterns in vital exhaustion

    J. Psychosom. Res.

    (2000)
  • M. Sullivan et al.

    The Swedish SF-36 Health Survey–I. Evaluation of data quality, scaling assumptions, reliability and construct validity across general populations in Sweden

    Soc. Sci. Med.

    (1995)
  • R. Yehuda et al.

    Hypothalamic–pituitary–adrenal dysfunction in posttraumatic stress disorder

    Biol. Psychiatry

    (1991)
  • J.L. Abelson et al.

    HPA axis activity in patients with panic disorder: review and synthesis of four studies

    Depress. Anxiety

    (2007)
  • A. Appels

    Psychological prodromata of myocardial infarction and sudden death

    Psychother. Psychosom.

    (1980)
  • A. Appels et al.

    The nature of the depressive symptomatology preceding myocardial infarction

    Behav. Med.

    (2000)
  • S. Cohen et al.

    Strategies for measuring stress in studies of psychiatric and physical disorders

  • M.A. Demitrack et al.

    Evidence for and pathophysiologic implications of hypothalamic–pituitary–adrenal axis dysregulation in fibromyalgia and chronic fatigue syndrome

    Ann. N. Y. Acad. Sci.

    (1998)
  • B.P. Dohrenwend

    Inventorying stressful life events as risk factors for psychopathology: toward resolution of the problem of intracategory variability

    Psychol. Bull.

    (2006)
  • N. Frasure-Smith et al.

    Recent evidence linking coronary heart disease and depression

    Can. J. Psychiatry

    (2006)
  • C.F. Gillespie et al.

    Hypercortisolemia and depression

    Psychosom. Med.

    (2005)
  • A.K. Goenjian et al.

    Basal cortisol, dexamethasone suppression of cortisol, and MHPG in adolescents after the 1988 earthquake in Armenia

    Am. J. Psychiatry

    (1996)
  • Cited by (0)

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