Measuring the hair cortisol level may be indicative of psychological stress, suggests a study published in the journal PLoS Global Public Health.¹

To analyse the association between hair cortisol concentration (HCC) and perceived stress, hair samples were obtained from 398 women from the Icelandic stress and gene analysis (SAGA) pilot-cohort and 881 from the Mexican Teachers’ Cohort. The hair samples were collected from the back of the head (posterior vertex). “As hair grows an estimated 1 cm per month, the 3 cm closest to the scalp represent the prior three months”, note the authors.

The hair cortisol levels, measured by liquid chromatography and tandem mass spectrometry, were higher among the Mexican participants compared to the Icelandic women; 6.0pg/mg vs. 4.7pg/mg (median), respectively. They also had higher psychological stress as assessed by the self-reported Perceived Stress Scale (PSS, 10 and 4 item, range 0–40 and 0–16); 12.4 vs. 11.7, respectively. When the Mexican and Icelandic women were examined as one group, it was found that for every unit increase in the PSS-10 score, the hair cortisol levels increased by 1.45 after adjusting for behavioral, social and demographic factors. The cortisol levels increased by 24.3% from the lowest to the highest quintile on the PSS scale.

This study has linked hair cortisol concentration and perceived stress in two diverse groups of participants in a linear association. The levels were higher among women who scored the highest on the PSS scale. This association remained unchanged even after adjusting for multiple variables, “though the absolute difference was small”.

Reference

1. Lynch R, et al. Perceived stress and hair cortisol concentration in a study of Mexican and Icelandic women. PLOS Glob Public Health.2022;2(8):e0000571. https://doi.org/10.1371/journal.pgph.0000571.