A Cortisol Study; Facial Hair and Nails

Abstract

Current methods for measuring cortisol levels can be challenging due to the need to take multiple urine, saliva or serum samples. Therefore, it seems necessary to find alternative matrices which can be used as stress indicators in which sample collection methods are non-invasive. Two experiments were conducted to first to test the feasibility of cortisol levels in facial hair and second to find a correlation among facial hair cortisol and cortisol levels in nails. In the first experiment, facial hair from five subjects was analyzed to confirm the presence of cortisol. The results of the assessment of facial hair showed that facial hair may be used to measure cortisol levels over a short period of time. In the second experiment, nineteen university students (males who regularly partake in martial arts-aged: 22 ± 3.15) provided fingernail, toenail and facial hair samples at set intervals throughout the school year; 1) The Study Periodduring the student's everyday life (minimal stress conditions, baseline), 2) The Exam Period-following student's final exams (mental stress), and 3) The Fighting Period-following intensive martial arts training (physical stress). Cortisol in facial hair, toenails, and fingernails showed higher levels during both the Exam Period and the Fighting Period when compared to the baseline Study Period (p<0.05). However, no differences in cortisol levels were observed among the indices during the Exam Period and Fighting Period (p>0.05). A higher correlation in cortisol levels was observed between facial hair samples and toenails (r=0.73) than between fingernails and toenails (r=0.61). Overall, cortisol levels showed significant correlations between fingernails and toenails (p=0.001, r=0.61), fingernails and facial hair (p=0.01, r=0.54), and toenails and facial hair (p=0.001, r=0.73). Further research is needed to understand the relationship between facial hair and nail cortisol and their possible relationship with health disorders.

Salivary Cortisol Interactions in Search and Rescue Dogs and Their Handlers

“…Saliva, urine, feces, and hair (coat) are non-invasively sampled biological materials used for assessment of cortisol levels. Cortisol can be determined even in nails [28].…”

Innovations in biological assessments of chronic stress through hair and nail cortisol: Conceptual, developmental, and methodological issues

“…Recently, Wu et al () showed an association between present perceived stress and increased nail cortisol among 51 medical students from China. In a small study of 19 university students, nail cortisol was higher during exam periods (Nejad et al, ). Nail cortisol was also positively correlated with stressful life events but not job stress or perceived stress in middle aged men and women (Izawa, Matsudaira, Miki, Arisaka, & Tsuchiya, ).…”

“…An unpublished study presented in 2016 assessed nail cortisol in 124 at‐risk children at 24 and 36 months but showed stability across time points in only a third of the children (Nejad et al, ). In a recent study, nail cortisol was also not found to be associated with diurnal measures of salivary cortisol among 324 children between 2 and 6 years of age (Messerli‐Bürgy et al, ).…”

Hair Cortisol and Perceived Stress in Health-studies Students during Summer Break and Fall Term

“…In contrast to these studies, the level of stress in the present study may not have been of sufficient intensity to trigger a cortisol response. A recent study by Nejed et al [4] examined cortisol concentrations in facial hair and nails of university students. The authors found that cortisol level was higher during a 10 day period of exams compared to a 10 day exam-free period.…”