Daytime somnolence as an early sign of cognitive decline in a community‐based study of older people

Abstract

Objective This study aimed to examine the association between self-reported sleep problems and cognitive decline in community-dwelling older people. We hypothesized that daytime somnolence predicts subsequent cognitive decline. Methods This is a longitudinal study in a 3.2-year follow-up, with 18-month intervals. The setting is the Washington Heights-Inwood Community Aging Project. There were 1098 participants, who were over 65 years old and recruited from the community. Sleep problems were estimated using five sleep categories derived from the RAND Medical Outcome Study Sleep Scale: sleep disturbance, snoring, awaken short of breath/with a headache, sleep adequacy, and daytime somnolence. Four distinct cognitive composite scores were calculated: memory, language, speed of processing, and executive functioning. We used generalized estimating equations analyses with cognitive scores as the outcome, and time, sleep categories and their interactions as the main predictors. Models were initially unadjusted and then adjusted for age, gender, education, ethnicity, depression, and apolipoprotein E-ε4 genotype. Results Increased daytime somnolence (including feeling drowsy/sleepy, having trouble staying awake, and taking naps during the day) was linked to slower speed of processing both cross-sectionally (B = −0.143, p = 0.047) and longitudinally (B = −0.003, p = 0.027). After excluding the demented participants at baseline, the results remained significant (B = −0.003, p = 0.021). Conclusions Our findings suggest that daytime somnolence may be an early sign of cognitive decline in the older population. Copyright # 2015 John Wiley & Sons, Ltd.

Sleep and subjective cognitive decline in cognitively healthy elderly: Results from two cohorts

“…An alternative explanation of our findings is that both SCD and sleep dysregulation are initial symptoms of an undetected subclinical neurodegenerative disease. Indeed, MCI and dementia—especially AD—have both been associated with increased sleep dysregulation (Lim, Kowgier, Yu, Buchman, & Bennett, ; Tsapanou, Gu, Manly, et al., ; Tsapanou, Gu, O'Shea, et al., ), and existing literature points to the presence of AD biomarkers in adults expressing SCD. Overall, therefore, although we were careful to exclude subjects with dementia or even MCI, and to additionally adjust for objective cognition, we cannot fully exclude the possibility that both sleep problems and the self‐perception of the cognitive performance could still be an indication of preclinical cognitive alterations that could lead to future dementia.…”

“…We could hypothesize that sleep problems may be causing more SCD. Poor sleep quality has been associated with low cognitive performance, especially in the elderly (Tsapanou, Gu, Manly, et al, 2015;Tsapanou, Gu, O'Shea, et al, 2015;Yaffe et al, 2011).…”

“…elderly, healthy ageing, sleep problems, subjective cognitive decline 1 | INTRODUCTION Sleep quality has been associated with objective cognitive performance in many studies, especially in the elderly population (Jaussent et al, 2012;Tsapanou, Gu, Manly, et al, 2015;Tsapanou, Gu, O'Shea, et al, 2015;Xu et al, 2014). Moreover, specific sleep problems have been found to be significant risk factors for developing both mild cognitive impairment (MCI) and dementia, mostly Alzheimer's disease (AD) type (Jelicic et al, 2002;Ju et al, 2013;Tsapanou, Gu, Manly, et al, 2015;Tsapanou, Gu, O'Shea, et al, 2015;Yaffe et al, 2011). Objective cognitive performance is often, but not always, related to subjective cognitive decline (SCD), which is the self-perception of cognitive changes in comparison to a previously normal state (Tandetnik et al, 2015).…”

Self-Reported Sleep Disordered Breathing as Risk Factor for Mortality in the Elderly

“…Sleep problems are common among the elderly population [1] and have been linked to many disorders in the specific age group [2-4]. In particular, sleep disordered breathing (SDB) – including difficulties breathing during sleep- has a high prevalence among older adults, and often occurs even with atypical symptoms [5, 6].…”

Napping: when sleep is bad for you?

“…At the outset the authors argue that many laboratory studies in young healthy adults have shown that napping is good for memory and alertness, so it may be expected that those older people who nap perform better and are more alert. This expectation is countered by epidemiological studies showing that naps, and in particular long naps, are associated in general with poor health, mortality and cognitive decline (Tsapanou et al ., ; Yamada et al ., ). The data of the present study are clear: nappers are more sleepy, have a higher body mass index and a higher cumulative illness rating than non‐nappers.…”