Hair cortisol and the relationship with chronic pain and quality of life in endometriosis patients

Endometriosis is a chronic estrogen-dependent disease in which pelvic pain is the dominant symptom. The negative effects of endometriosis on the life of women with this disease can be a cause of stress. Stress levels can be measured in different ways, mostly reflecting acute stress responses. Hair cortisol measurements are a reflection of long-term systematic cortisol levels. In this study a first attempt is made to measure cortisol levels in hair of endometriosis patients in comparison with healthy controls. Moreover, it is explored whether chronic pain symptoms as well as different aspects of Health Related Quality of Life (HRQoL) are associated with hair cortisol levels in women with endometriosis. Results show that the mean hair cortisol level is significantly higher in women with endometriosis compared to healthy controls (p = 0.018). There is a positive correlation between hair cortisol level and HRQoL in patients but not in controls (Rho 0.426). The level of hair cortisol does not correlate with the reported pain intensity in patients (Rho -0.082). These results are indicative of an altered HPA-axis function in endometriosis patients, possibly caused by higher chronic stress level in these patients. Moreover, a potential explanation for the positive correlation of cortisol with the HRQoL in these patients is that patients with a high HRQoL have an adequate stress response by increasing their cortisol levels as a response to physical and emotional stress induced by the endometriosis.