Hair cortisol in relation to sociodemographic and lifestyle characteristics in a multiethnic US sample

We investigated the feasibility of obtaining hair samples from men and women at community-based barbershops and hair salons for analysis of cortisol and assessed sociodemographic and lifestyle correlates of hair cortisol concentrations (HCCs). A total of 102 participants completed the study.

Research staff interviewed participants using a structured questionnaire, and samples of hair were collected. HCCs were determined using liquid chromatography-tandem mass spectrometry. Age- and sex-adjusted linear regression models were used to evaluate the association of HCC with covariates.

Analyses by race/ethnicity showed highest median HCC in blacks (12.5 [6.9-29.3]) pg/mg) followed by Hispanics (10.7 [5.8-14.9] pg/mg), whites (5.0 [3.8-10.8] pg/mg), and other participants (4.2 [3.3-15.7] pg/mg), P < .01. Current smokers had significantly higher median HCC (11.7 [8.8-18.9] pg/mg) compared with former smokers (4.6 [3.5-14.6] pg/mg) and those who had never smoked (6.9 [4.7-12.8] pg/mg), P = .04. After adjustment for age and sex, geometric mean HCC was 0.72 pg/mg lower in dyed hair compared with hair that was not dyed (β = -0.72, standard error = 0.30, 95% confidence interval, -1.29 to -0.15, P = .02).

HCC can be assessed in community-based studies. Future HCC studies should consider cosmetic hair treatment, cigarette smoking, and the potential role of psychosocial stressors in the association between race/ethnicity and HCC.