Sleep duration and the cortisol awakening response in dementia caregivers utilizing adult day services

Sleep complaints are common among caregivers and are associated with detriments in mental and physical health. Cortisol, a biomarker of the stress process, may link sleep with subsequent health changes in caregivers. The current study examines whether sleep duration is directly associated with the cortisol awakening response (CAR), or whether it is moderated by Adult Day Services (ADS) use, an intervention found previously to influence daily CAR by reducing stressor exposure.

Associations were examined in caregivers (N = 158) of individuals with dementia (IWD) on days when IWDs attended ADS and days when IWDs did not attend ADS. Data were gathered over 8 consecutive days. Caregivers were primarily female (87.3%) with a mean age of 61.59. A multilevel growth curve model tested the association of an interaction of today's ADS use and last night's sleep duration with today's CAR as the outcome.

The interaction between ADS use and within-person sleep duration was significant such that when an individual sleeps longer than their average but does not use ADS, they have a smaller or blunted CAR. On the other hand when an individual sleeps longer than their average and uses ADS, they have a higher but nonsignificant CAR. Sleeping shorter than usual was associated with a dynamic rise regardless of ADS use.

Findings indicate that ADS use moderates the association between sleep duration and CAR such that longer than average sleep is associated with blunted, dysregulated cortisol patterns only on non-ADS days.