JMIR Publications

ABSTRACT

Background:

Hair cortisol is an emerging biomarker of chronic stress. To determine its clinical utility, the elements of cortisol production and regulation reflected in hair cortisol concentration (HCC) across different populations with differing degrees and types of psychological stressors need to be remain undetermined. Since cortisol is incorporated into growing hair and physiologic stress reactivity is not consistently correlated with stress perception, we speculated that HCC is more strongly correlated with somatic neuroendocrine stress indices than with stress perception.

Objective:

This study aimed to evaluate subjective (Perceived Stress Scale, Connor-Davidson Resilience Scale) and objective (plasma cortisol/DHEA(S) and cortisol/hs-CRP) determinants of HCC.

Methods:

In this cross-sectional pilot validity study, scatter plots and Spearman’s correlation coefficients were used to measure the direction and magnitude of the relationship between stress and resilience measures among 51 participants. In a subset (n=24), we performed a step-wise regression modeling approach to isolate the impact of perceived and somatic stress on hair cortisol.

Results:

Bivariate correlations showed a weak inverse association of HCC with PSS (Spearman’s rho = -0.14, p = 0.52) but a stronger positive association with somatic neuroendocrine stress indices cortisol/DHEAS (Spearman’s rho = 0.24, p = 0.25) and cortisol/hs-CRP (Spearman’s rho = 0.21, p = 0.35). In linear regression models, HCC showed the strongest association with cortisol/DHEAS (r2= 0.10, p = 0.13, 1.01???? 1.01, 95% confidence interval (CI) 0.998-1.012). This relationship remained when age, gender, hair washing frequency, hair dye or bleach use, diabetes mellitus, obesity, cardiovascular disease, anxiety, medication use, and endocrine disorders were considered.

Conclusions:

Although our findings did not reach statistical significance at the p<.05 threshold, results from our pilot study suggest HCC shows a stronger association with neuroendocrine stress measures than with perceived stress. Additionally, the association of HCC with cortisol/DHEAS invites the possibility that indices including resiliency may complement HCC as chronic stress measurements.