Hair Cortisol as a Biomarker for Stress


Research from the lab of Prof. William Potter

It’s very popular these days to talk about stress, but actually determining what stress is and how much you have, is quite a different matter. Is the stress from an all-night study binge anywhere close to that experienced by a veteran of war, or a rape victim?  How do some traumatized people cope so well while others succumb to worsening events?

We know that both physical and psychological events will trigger stress, but determining how one’s genetics, immune system, state of health and their diet can influence the stress outcome is not well-understood.  Overall, in collaboration with TU’s Tulsa Institute for Trauma, Abuse and Neglect (TITAN), the Laureate Institute of Brain Science (LIBR), the Institute for Biochemical and Psychological Study of Individual Differences (IBPID) and with TU’s Athletic Training/ Exercise Sport Science collaborators, we are studying the genetic and biochemical markers of stress. 

From the biochemical viewpoint, stress signals are integrated into hormonal cascades of adrenergic and glucocorticoid signaling. The hypothalamus signals through the pituitary to activate the adrenals.  The release of cortisol and other modulators ultimately provide feedback such that only a graded homeostatic response should occur, but, unfortunately, life is not always that simple! Having concurrent infections, being a type II diabetic, having no suitable “fight or flight” response, having elevated levels of other steroidal hormones, all appear to predispose an individual to inappropriate responses.  In the Potter lab, we measure stress levels using cortisol extracted from hair.  Hair has the advantage of avoiding diurnal variations and provides for a time-averaged value for cortisol. The goal in our lab, to paraphrase Lord Kelvin, is to put a value on cortisol and on the stress response.

William Thomson (June 26, 1824–December 17, 1907), 1st Baron Kelvin, often referred to simply as Lord Kelvin, was a Scottish physicist.

“I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.”