Relationship of Hair Cortisol Concentration With Perceived and Somatic Stress Indices: Cross-Sectional Pilot Study.

Background: Hair cortisol is an emerging biomarker of chronic stress. However, the psychological and physiological aspects of chronic stress that are reflected in hair cortisol concentration (HCC) have not been fully determined. Since physiological responses to stress do not always align with how stress is perceived, we conducted this study to evaluate whether HCC correlates with neuroendocrine stress indicators or stress perceptions.

Objective: This study aimed to evaluate whether subjective (Perceived Stress Scale and Connor-Davidson Resilience Scale) and objective (plasma cortisol/dehydroepiandrosterone-sulfate [DHEA-S] and cortisol/high-sensitivity C-reactive protein) determinants of stress and resilience correlate with HCC.

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

Results: Bivariate correlations showed a weak inverse association of HCC with Perceived Stress Scale (Spearman correlation ρ=-0.14, P=.52) and a stronger positive association with somatic neuroendocrine stress indices cortisol/DHEA-S (ρ=0.24, P=.25) and cortisol/high-sensitivity C-reactive protein (ρ=0.21, P=.35). In linear regression models, HCC showed the strongest association with cortisol/DHEA-S (r2=0.10, P=.13, 1.01β 1.01, 95% CI 0.99-1.01). 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: Our results do not indicate a statistically significant association (at the P<.05 threshold) between HCC and stress perception or somatic measures of neuroendocrine response.