Cortisol dysregulation is associated with daily diary-reported hot flashes among midlife women

Objective Hot flashes are reported by 70-80% of women during the menopause transition. It has been proposed that cortisol dysregulation is involved in hot flashes, but the relationship between cortisol and hot flashes has received little empirical attention. This study examined the relationship between cortisol and daily self-reported hot flashes. Design For 7 days, participants used electronic diaries to report their hot flash frequency, severity and bothersomeness, along with mood and health behaviours, multiple times each day. Participants also provided hair samples for cortisol assays at baseline and morning and bedtime saliva samples for salivary cortisol collection over 3 days during the observation period. Hierarchical linear regression was used to examine the relationships between cortisol and hot flashes. Participants Forty-four women (41% African American, 39% non-Hispanic White) who reported daily hot flashes were enrolled. Measurements Salivary cortisol, hair cortisol and the frequency, severity and bothersomeness of daily diary-reported hot flashes were measured in this study. Results Controlling for health and demographic variables, higher hair cortisol was associated with a higher frequency of hot flashes (beta = 0.05, P = 0.01). A flatter diurnal cortisol slope was associated with greater hot flash severity (beta = 0.09, P = 0.03) and bother (beta = 0.10, P = 0.01). Hair cortisol was no longer significant after adjusting for depression or disturbed sleep; all other associations persisted. Conclusion Cortisol dysregulation was related to more frequent, severe and bothersome daily self-reported hot flashes. These findings support a potential role of the HPA axis in the aetiology and phenomenology of these common menopause symptoms.