Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders

Abstract

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of findings from scientific literature on this field are presented. There is evidence of a close relationship between HPA functional alteration and the development of neuropsychiatric disorders. Sleep disorders are the most common manifestation in several neuropsychiatric conditions, and have also been associated to cortisol alterations in both adults and children. Many studies indicate that hair cortisol constitutes a valuable tool for further contributing to existing data on salivary, plasma, or urinary cortisol concentrations in patients with sleep disorders.

Higher Levels of Stress-Related Hair Steroid Hormones Are Associated with the Increased SCORE2 Risk Prediction Algorithm in Apparently Healthy Women

“…Furthermore, recently published data revealed a mediating effect of the hair cortisol concentration between shift work and sleep disorders [ 21 ]. It is suggested that the association between poor sleep quality and increased HPA axis activity is bidirectional: activation of the HPA axis might lead to inadequate sleep duration, diminished slow-wave sleep and sleep fragmentation, while insufficient sleep results in elevated glucocorticoid levels [ 23 ]. Thus, our results suggest that both poor sleep quality and higher perceived stress level are associated with an increased hair cortisol concentration, which, in turn, is related to a higher cardiovascular disease risk.…”

“…The main advantages of using hair cortisol as a biomarker of chronic stress compared with other specimens (i.e., blood serum, saliva, urine) are: the fairly predictable growth rate (1 cm/month) that allows retrospective assessment of integrated cortisol secretion; the non-invasive sample collection procedure and small amount of sample required for analysis; the easy sample storage, as samples can be stored at room temperature over long periods of time; and the lack of situational confounding factors, such as circadian rhythmicity, acute stress, smoking, alcohol consumption, food intake and intensive physical exercise [ 17 , 19 ]. Previous studies showed that an increased hair cortisol concentration is associated with long-term unemployment [ 20 ], shift work [ 21 ], severe chronic pain [ 22 ], sleep disorders [ 23 ] and psychopathologies, including post-traumatic stress disorder [ 24 ], major depression [ 25 ] and bipolar disorder [ 26 ]. Other, less extensively studied steroid hormones—cortisone and dehydroepiandrosterone (DHEA)— might also be considered stress biomarkers.…”

The Association between Endogenous Hair Steroid Hormones and Social Environmental Factors in a Group of Conscripts during Basic Military Training

“…Amongst other steroid hormones, hair cortisol is widely used as the primary biomarker of long-term exposure to chronic stress in a broad spectrum of psychoneuroendocrinological studies [9,13,14]. Increased hair cortisol levels were found in various contexts (e.g., endurance athletes [42][43][44], shift work [21], sleep and mental disorders [45], unemployment [46], chronic pain [47], or major life events [48]). Long-term elevations in serum [49] and hair cortisol [50] have been also reported during stressful military captivity training.…”

Split-Second Unlearning: Developing a Theory of Psychophysiological Dis-ease

“…This draws on multiple interactions between physiological, emotional and cognitive systems. The stress response, which encompasses the amygdala and HPA axis simultaneously, plays a key role in a broad range of mental and physical health conditions including psychopathology associated with early adverse experiences ( Felitti et al, 1998b ; Juruena et al, 2020 ; El Mlili et al, 2021 ). This interdependent relationship between the psychological trauma and physiological stress was formally outlined by Selye (1946) , referred to as “general adaptation syndrome,” and has since been increasingly refined.…”

“…take some time to subside. Regular HPA stimulation therefore puts the body through a great deal of stress and has been implicated in a range of psychophysical problems, including systemic inflammation ( Powers et al, 2019 ), adverse immune responses ( Antoni and Dhabhar, 2019 ), sleep disorders ( Buckley and Schatzberg, 2005 ; El Mlili et al, 2021 ), memory problems ( Labad et al, 2020 ), and major depression ( Pariante and Lightman, 2008 ; Menke et al, 2018 ). We also speculate that persistent repeated stimulation of this stress response might have a similar effect to “learned helplessness,” which also leads to clinical depression ( Miller and Seligman, 1975 ; Danese and McEwen, 2012 ).…”