Sleep health and subjective cognitive decline in the Vanderbilt Memory and Aging Project

Abstract

AbstractBackgroundIdentifying modifiable risk factors for Alzheimer’s disease (AD) and related dementias (ADRD) may reveal critical evidence for early prevention. It is commonly believed that poor sleep is an early symptom of neurodegeneration and ADRD. However, distinct neurobiological processes occur during sleep, and dysfunction of these processes may also contribute to AD pathogenesis. Less is known about poor sleep and associations with subjective cognitive decline (SCD), a clinical symptom occurring before overt cognitive impairment due to early pathological AD. This study investigated associations between objective and self‐reported measures of sleep health and SCD in a community‐based cohort of older adults.MethodParticipants from the Vanderbilt Memory and Aging Project (n = 220; 74±7 years; 34% female) completed 7‐days of wrist actigraphy and self‐report measures for SCD [Everyday Cognition Scale (ECog)] and sleep quality [Pittsburgh Sleep Quality Index (PSQI)]. Actigraphy data was processed to estimate average nightly sleep duration, sleep efficiency, and wake after sleep onset. Linear regressions related objective and self‐report sleep health measures with total ECog score adjusting for age, sex, race/ethnicity, education, body mass index, depressive symptoms, Framingham cardiovascular risk score, and apolipoprotein E‐e4 carrier status.ResultIn main effect models, longer sleep duration was associated with greater SCD (b = 0.05, p<0.01). In models adjusted for age, sex, race/ethnicity, and education, higher PSQI (indicative of poorer sleep quality) was associated with greater SCD (b = 1.06, p = 0.01); however, the association was no longer statistically significant in the fully adjusted model. No associations were observed between sleep efficiency or wake after sleep onset and SCD.ConclusionIn this community cohort of older adults, longer nightly sleep duration and self‐reported poor sleep quality were linked with higher SCD. Findings could suggest that abnormal sleep duration and poor sleep quality increase the earliest clinical symptoms of AD. Further investigations are needed to evaluate the potential pathways connecting sleep health to ADRD development.