Cortisol and wake time in nursing home residents with behavioral symptoms of dementia.

Alterations in sleep and behavioral symptoms are consistently reported among nursing home residents with dementia. Disregulation in the hypothalamic-pituitary-adrenal axis (HPA), indexed by basal cortisol levels, offers one explanation. The purpose of this study is to examine the relationship between wake time and cortisol slope in residents with behavioral symptoms. The study included 27 residents aged 71 to 84 years with dementia and behavioral symptoms. Using a within-subject longitudinal design, the researchers documented wake time and collected saliva samples for 4 consecutive days upon waking and at 30 min, 6 hr, and 12 hr after waking. Within-person cortisol slopes were categorized into zero-positive and negative slopes. The zero-positives (35%) exhibited an earlier wake time than the negatives (65%). These preliminary results suggest both a relationship between wake time and HPA diurnal profile and an association between the sleep-wake cycle and cortisol secretion among nursing home residents with dementia.