This study examined the relationships between diurnal cortisol patterns and sleep behavior, social support, psychological factors, and perceived health status in breast cancer patients.
One hundred and eighty-one breast cancer patients completed a self-report questionnaire that combined the Hospital Anxiety and Depression Scale, the Yale Social Support Scale, and self-perceived measures of physical health, stress, sleep quality, total sleep hours, and time of awakening. Salivary cortisol was collected upon waking, at 1200h, 1700h, and 2100h on two consecutive days. Multiple regression analysis was performed on the diurnal cortisol slope that was derived from slope analysis of the log-transformed cortisol data.
Controlling for the initial cortisol level, a flatter diurnal cortisol slope was significantly associated with a later time of awakening, higher negative social support, poorer perceived health, poorer sleep quality, and shorter total sleep hours. Anxiety and depression were not significantly correlated with the slope.
The results indicate a subtle dysregulation in hypothalamic-pituitary-adrenal axis functioning in patients with highly negative social support, poor perceived health, poor sleep quality, a later time of awakening, and insufficient sleep hours.