Risk and resiliency factors associated with poor sleep quality in elderly populations

Abstract

According to the National Sleep Foundation’s 2020 Sleep in America® poll, Americans report feeling sleepy an average of three days a week, with many saying it impacts their daily activities, mood, mental acuity, and productivity.1 Among those reporting the highest frequencies of sleepiness, and an increased frequency of naps, are older Americans—with significantly higher proportion increasing with age: 24% for 75–84 year-olds as compared to 10% of 55–64 year-olds.2 Advanced aging, and accompanying health complications, appear to be a major contributor to the poor sleep quality experienced by older adults. Under normal conditions, the circadian rhythm promotes a regular daily cycle of nighttime sleep and daytime wakefulness and alertness.3 Aging transforms sleep architecture in a number of ways causing many sleep-related problems that directly impact health and cognition. For example, polysomnographic studies with older adults show that sleep is characterized by a decline in total sleep time and sleep efficiency;4,5 longer sleep onset latency, increased waking after sleep onset, and sleep fragmentation.6,7 In a study by Mander and colleagues8 it was demonstrated that medial prefrontal cortex (mPFC) grey-matter atrophy exhibited in a small sample of older adults contributed to reduced NREM slow save activity (SWA), resulting in impaired long-term memory. Of clinical significance in the elderly, sleep disturbance is associated with decreased memory, impaired concentration, and impaired functional performance.9 Studies have confirmed that electroencephalogram (EEG) data in older adults show a decline in slow waves amplitude10 and a reduction in density and amplitude of sleep spindles.11 This change may be associated with the age-related cognitive impairments reported by older adults resulting from a weakening or disruption of the memory storage processes underlying sleep-dependent memory consolidation.12 Sleep is known to play a role in memory formation of newly learned information [for a review see 13];13 a finding reported in the literature to be tied to possible evolutionary advantages.14 Considering the important role that sleep plays in everyday life, it should not be dismissed as something that for older adults, is just a normal part of aging. In this short review, we highlight the impact of 4P factors that moderate the effects of sleep quality in older adults including: Predisposing factors; perpetuating factors; precipitating factors; and protective factors.