Longitudinal Association Between Saliva and Hair Cortisol Concentration: A Systematic Comparison
October 2023
in “
Psychoneuroendocrinology
”
TLDR Hair cortisol is a reliable marker of long-term cortisol levels and is linked to daytime saliva cortisol but not morning levels.
The study aimed to compare the cortisol levels in saliva and hair to understand their correlation. The study involved 54 healthy female second-year students and lasted seven weeks. Saliva samples were taken at three different weeks (6, 4, and 2 weeks prior) to hair cortisol sampling. The study found consistent associations between hair cortisol concentration (HCC) and cortisol secretion over the rest of the day (DAYauc) collected two weeks, four weeks, and six weeks before hair sampling. However, there was no significant association between HCC and total post-awakening cortisol secretion (CARauc). The study concluded that hair cortisol concentration is a reliable indicator of long-term cortisol output, reflecting cortisol secretion throughout the day, but not immediately after waking.
