The 24/7 work environment and irregular shifts may markedly enhance the psychological pressure of media work. Changes in the hypothalamic-pituitary-adrenal axis reflect adaptation to stress. We analysed the correlation between subjective stress, sleep, salivary cortisol, and melatonin hormones among Finnish media workers with regular daytime work (RDW) and with irregular shift work (ISW) while controlling confounders. From 874 employees with regular daytime work or with irregular shift work, 70 employees from both groups were randomly selected. The final number of employees with a complete salivary cortisol profile was 66 in the RDW group and 65 in the ISW group. Five saliva samples were gathered from each subject before and during a working day. The salivary cortisol level of the sample taken 60 minutes after awakening (T1) was compared to the salivary cortisol level taken immediately after awakening (T0, T1/T0 ratio). The ratio was higher in the ISW group than in RDW group. Irregular shift work ( ), severe stress ( ), and less sleep ( ) were independently associated with an augmented cortisol response after awakening. A stressful work environment and irregular shift work enhance cortisol excretion after waking. In the long run, this may become detrimental to health. 1. Introduction The hypothalamic-pituitary-adrenal (HPA) axis is one of the main components of the stress adaptation system in humans [1]. Bursts of cortisol excretion oscillate diurnally and the amplitude of these bursts increase during morning hours. Environmental factors and mental stress may disrupt the balance in this cycle [2]. Augmented cortisol responses have been associated with metabolic syndrome, atherosclerosis, osteoporosis, immunosuppression, and an increased risk of coronary heart disease [1, 3]. Work-related stressors have been associated with augmented cortisol responses [4]. Poor recovery, long working hours, and an extensive physical workload affect cortisol reactivity [5–7]. Also short sleep duration and self-reported sleep disturbances may disrupt diurnal cortisol secretion patterns [8]. Combined evaluation of subjective and physiological stress might be useful to detect risk groups and determinants of poor health outcomes from working life. Ideally, the tools should be easily implemented in occupational health care. According to Elo and collaborators [9], a single question can be used in the evaluation of job stress. Salivary cortisol analyses have been used to monitor the HPA axis function [10]. In addition to self-reported sleep, wrist actigraphy can be used to
References
[1]
C. Tsigos and G. P. Chrousos, “Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress,” Journal of Psychosomatic Research, vol. 53, no. 4, pp. 865–871, 2002.
[2]
A. Papadimitriou and K. N. Priftis, “Regulation of the hypothalamic-pituitary-adrenal axis,” NeuroImmunoModulation, vol. 16, no. 5, pp. 265–271, 2009.
[3]
T. Chandola, A. Britton, E. Brunner et al., “Work stress and coronary heart disease: what are the mechanisms?” European Heart Journal, vol. 29, no. 5, pp. 640–648, 2008.
[4]
G. Maina, A. Palmas, M. Bovenzi, and F. L. Filon, “Salivary cortisol and psychosocial hazards at work,” American Journal of Industrial Medicine, vol. 52, no. 3, pp. 251–260, 2009.
[5]
J. K. Sluiter, M. H. W. Frings-Dresen, A. J. Van Der Beek, and T. F. Meijman, “The relation between work-induced neuroendocrine reactivity and recovery, subjective need for recovery, and health status,” Journal of Psychosomatic Research, vol. 50, no. 1, pp. 29–37, 2001.
[6]
C. Thomas, C. Hertzman, and C. Power, “Night work, long working hours, psychosocial work stress and cortisol secretion in mid-life: evidence from a British birth cohort,” Occupational and Environmental Medicine, vol. 66, no. 12, pp. 824–831, 2009.
[7]
J. F. Thayer, B. Verkuil, J. F. Brosschot et al., “Effects of the physical work environment on physiological measures of stress,” European Journal of Cardiovascular Prevention and Rehabilitation, vol. 17, no. 4, pp. 431–439, 2010.
[8]
M. Kumari, E. Badrick, J. Ferrie, A. Perski, M. Marmot, and T. Chandola, “Self-reported sleep duration and sleep disturbance are independently associated with cortisol secretion in the Whitehall II study,” Journal of Clinical Endocrinology and Metabolism, vol. 94, no. 12, pp. 4801–4809, 2009.
[9]
A. L. Elo, A. Lepp？nen, and A. Jahkola, “Validity of a single-item measure of stress symptoms,” Scandinavian Journal of Work, Environment and Health, vol. 29, no. 6, pp. 444–451, 2003.
[10]
W. S. Gozansky, J. S. Lynn, M. L. Laudenslager, and W. M. Kohrt, “Salivary cortisol determined by enzyme immunoassay is preferable to serum total cortisol for assessment of dynamic hypothalamic-pituitary-adrenal axis activity,” Clinical Endocrinology, vol. 63, no. 3, pp. 336–341, 2005.
[11]
J. L. Martin and A. D. Hakim, “Wrist actigraphy,” Chest, vol. 139, no. 6, pp. 1514–1527, 2011.
[12]
A. Steptoe, M. Cropley, J. Griffith, and C. Kirschbaum, “Job strain and anger expression predict early morning elevations in salivary cortisol,” Psychosomatic Medicine, vol. 62, no. 2, pp. 286–292, 2000.
[13]
I. Wilhelm, J. Born, B. M. Kudielka, W. Schlotz, and S. Wüst, “Is the cortisol awakening rise a response to awakening?” Psychoneuroendocrinology, vol. 32, no. 4, pp. 358–366, 2007.
[14]
A. Clow, F. Hucklebridge, T. Stalder, P. Evans, and L. Thorn, “The cortisol awakening response: more than a measure of HPA axis function,” Neuroscience and Biobehavioral Reviews, vol. 35, no. 1, pp. 97–103, 2010.
[15]
Y. Chida and A. Steptoe, “Cortisol awakening response and psychosocial factors: a systematic review and meta-analysis,” Biological Psychology, vol. 80, no. 3, pp. 265–278, 2009.
[16]
T. Chandola, A. Heraclides, and M. Kumari, “Psychophysiological biomarkers of workplace stressors,” Neuroscience and Biobehavioral Reviews, vol. 35, no. 1, pp. 51–57, 2010.
[17]
I. Federenko, S. Wüst, D. H. Hellhammer, R. Dechoux, R. Kumsta, and C. Kirschbaum, “Free cortisol awakening responses are influenced by awakening time,” Psychoneuroendocrinology, vol. 29, no. 2, pp. 174–184, 2004.
[18]
R. H. Hong, Y. J. Yang, S. Y. Kim, W. Y. Lee, and Y. P. Hong, “Determination of appropriate sampling time for job stress assessment: the salivary chromogranin A and cortisol in adult females,” Journal of Preventive Medicine and Public Health, vol. 42, no. 4, pp. 231–236, 2009.
[19]
E. Fries, L. Dettenborn, and C. Kirschbaum, “The cortisol awakening response (CAR): facts and future directions,” International Journal of Psychophysiology, vol. 72, no. 1, pp. 67–73, 2009.
[20]
D. K. Mirick and S. Davis, “Melatonin as a biomarker of circadian dysregulation,” Cancer Epidemiology Biomarkers and Prevention, vol. 17, no. 12, pp. 3306–3313, 2008.
[21]
J. Kerlik, A. Penesova, M. Vlcek, R. Imrich, M. Vogeser, and Z. Radikova, “Comparison of salivary cortisol and calculated free plasma cortisol during low-dose ACTH test in healthy subjects,” Clinical Biochemistry, vol. 43, no. 9, pp. 764–767, 2010.
[22]
A. Clow, L. Thorn, P. Evans, and F. Hucklebridge, “The awakening cortisol response: methodological issues and significance,” Stress, vol. 7, no. 1, pp. 29–37, 2004.
[23]
A. Dahlgren, G. Kecklund, T. Theorell, and T. ？kerstedt, “Day-to-day variation in saliva cortisol-Relation with sleep, stress and self-rated health,” Biological Psychology, vol. 82, no. 2, pp. 149–155, 2009.
[24]
E. K. Adam and M. Kumari, “Assessing salivary cortisol in large-scale, epidemiological research,” Psychoneuroendocrinology, vol. 34, no. 10, pp. 1423–1436, 2009.
[25]
J. Ahlberg, M. K？n？nen, M. Rantala et al., “Self-reported stress among multiprofessional media personnel,” Occupational Medicine, vol. 53, no. 6, pp. 403–405, 2003.
[26]
H. Lindholm, J. Sinisalo, J. Ahlberg et al., “High job control enhances vagal recovery in media work,” Occupational Medicine, vol. 59, no. 8, pp. 570–573, 2009.
[27]
S. Ancoli-Israel, R. Cole, C. Alessi, M. Chambers, W. Moorcroft, and C. P. Pollak, “The role of actigraphy in the study of sleep and circadian rhythms,” Sleep, vol. 26, no. 3, pp. 342–392, 2003.
[28]
A. Hansen, A. H. Garde, J. M. Christensen, N. H. Eller, and B. Netterstr？m, “Evaluation of a radioimmunoassay and establishment of a reference interval for salivary cortisol in healthy subjects in Denmark,” Scandinavian Journal of Clinical and Laboratory Investigation, vol. 63, no. 4, pp. 303–310, 2003.
[29]
O. Martí, A. García, A. Vellès, M. S. Harbuz, and A. Armario, “Evidence that a single exposure to aversive stimuli triggers long-lasting effects in the hypothalamus-pituitary-adrenal axis that consolidate with time,” European Journal of Neuroscience, vol. 13, no. 1, pp. 129–136, 2001.
[30]
I. Bengtsson, L. Lissner, T. Ljung, A. Rosengren, D. Thelle, and P. W？hrborg, “The cortisol awakening response and the metabolic syndrome in a population-based sample of middle-aged men and women,” Metabolism: Clinical and Experimental, vol. 59, no. 7, pp. 1012–1019, 2010.
[31]
S. Puttonen, M. H？rm？, and C. Hublin, “Shift work and cardiovascular disease—pathways from circadian stress to morbidity,” Scandinavian Journal of Work, Environment and Health, vol. 36, no. 2, pp. 96–108, 2010.
[32]
J. Backhaus, K. Junghanns, and F. Hohagen, “Sleep disturbances are correlated with decreased morning awakening salivary cortisol,” Psychoneuroendocrinology, vol. 29, no. 9, pp. 1184–1191, 2004.
[33]
D. B. O'Connor, H. Hendrickx, T. Dadd et al., “Cortisol awakening rise in middle-aged women in relation to psychological stress,” Psychoneuroendocrinology, vol. 34, no. 10, pp. 1486–1494, 2009.
[34]
T. M. Buckley and A. F. Schatzberg, “On the interactions of the hypothalamic-pituitary-adrenal (HPA) axis and sleep: normal HPA axis activity and circadian rhythm, exemplary sleep disorders,” Journal of Clinical Endocrinology and Metabolism, vol. 90, no. 5, pp. 3106–3114, 2005.
[35]
J. J. Diez, D. E. Vigo, S. P. Lloret et al., “Sleep habits, alertness, cortisol levels, and cardiac autonomic activity in short-distance bus drivers: differences between morning and afternoon shifts,” Journal of Occupational and Environmental Medicine, vol. 53, no. 7, pp. 806–811, 2011.
[36]
A. S. Desantis, E. K. Adam, K. A. Mendelsohn, and L. D. Doane, “Concordance between self-reported and objective wakeup times in ambulatory salivary cortisol research,” International Journal of Behavioral Medicine, vol. 17, no. 1, pp. 74–78, 2010.
