Sleep and Executive Function in Older Women

Abstract

Age-related declines in cognitive processes are well documented (1), with executive functions at especially high risk for deteriorating with age (2,3). Executive functions (ie, attention, reasoning, impulse control, working memory) enable an individual to manage time, plan, organize, remember details, and behave appropriately (4). Performance of both complex activities (eg, using the phone, preparing a meal, driving) (5) and basic activities of daily living (eg, bathing, eating, dressing) (6) are affected by executive function. Thus, preserving executive function is vital for everyday functioning as well as for maintaining autonomy and quality of life, which is of great public health importance. Sleep (7,8) and physical activity (PA) (9–11) are thought to be important for cognitive function. However, few studies of cognitive function include comprehensive measurement of both sleep and PA. Additionally, few studies have considered how PA may affect the associations between sleep and cognitive function. Studying these relationships in older women may be particularly pertinent given the high prevalence of sleep disturbances (12,13) and low levels of PA (14,15) generally observed among this population subgroup. Moreover, preservation of executive function in woman may have the most profound implications for public health because women live longer than men and are subsequently at greater risk for Alzheimer’s disease (16). The purpose of this study was to assess the associations of both sleep and PA with cognitive function in older women. We hypothesized that poor sleep and low PA would be associated with worse cognitive function. Additionally, we examined the moderating effect of PA on associations between sleep and cognitive function. Importantly, we considered both direct (ie, device-based) and self-reported (ie, diary) measurements of sleep and PA.