Hair cortisol concentration associates with insomnia and stress symptoms in breast cancer survivors.

Stress, depressive symptoms and sleep quality are important and modifiable determinant of health and their association with hair cortisol concentrations (HCC) in breast cancer survivors has not been evaluated. We selected a random sample of 65 participants (mean age 57.9 years old, range 44-75 years) recruited from local patients' associations of breast cancer survivors. Each provided a hair sample at enrollment and basic clinical data and psychological evaluation regarding self-perceived stress (PSS-scale), depressive (GDS scale) and insomnia symptoms (Athens scale). We observed a direct and significant (p = 0.001) association between HCC and stress-levels. Depressive symptoms associated significantly (p < 0.01) with stress levels but not with HCC. There were also a significant and direct correlation between hair cortisol concentration and totals core of insomnia symptoms (p = 0.002), and the subdimension of sleep difficulty symptoms (p = 0.002), and with daytime sleepiness symptoms (p = 0.016). Further investigations into the association between stress and insomnia and changes in HCC in breast cancer survivors are warranted in order to validate this biomarker for diagnosis of psychological alterations and to tailor the effects of interventions aimed to reduced stress and improve sleep quality in these women.