Sleep Duration and Cognition in a Nationally Representative Sample of U.S. Older Adults

Association between frailty index and cognitive dysfunction in older adults: insights from the 2011-2014 NHANES data

Background

As the population ages, the occurrence of cognitive decline and dementia is continuously increasing. Frailty is a prevalent problem among older adults. Epidemiologic studies have shown a comorbidity between frailty and cognitive impairment. However, their relationship remains unclear. The frailty index is an important indicator for measuring frailty. This study aims to investigate the relationship between frailty index and cognitive dysfunction in older adults aged 60 years and older in the United States from the 2011-2014 National Health and Nutrition Examination Survey (NHANES).

Methods

Community-dwelling older adults aged 60 years or older from 2011 to 2014 were extracted from the NHANES database. The frailty index was calculated using the formula: frailty index = total number of deficits present/total number of deficits measured. The Animal Fluency (AF), the Digit Symbol Substitution Test (DSST), the Consortium to Establish a Registry for Alzheimer's disease Delayed Recall (CERAD-DR), and Word Learning (CERAD-WL) were used to evaluate cognitive dysfunction. Firstly, weighted logistic regression analysis was used to explore the relationship between frailty index and cognitive dysfunction. Secondly, the influence of covariates on the frailty index was evaluated by subgroup analysis and interaction. Finally, the non-linear relationship is discussed by using the restricted cubic spline regression model.

Results

Our study included a total of 2,574 patients, weighted logistic regression analysis, after adjusting for all covariates, showed that the frailty index was associated with every test score. The interaction showed that covariates had no significant effect on this association in AF. The association between the frailty index and AF in the restricted cubic spline regression model is non-linear. As the frailty index increased, the risk of AF reduction increased, suggesting a higher risk of cognitive dysfunction.

Conclusion

In general, a high frailty index appears to be associated with an increased risk of cognitive dysfunction in the elderly. Consequently, protecting against cognitive decline necessitates making geriatric frailty prevention and treatment top priorities.

Associations between sleep duration trajectories and cognitive decline: A longitudinal cohort study in China

OBJECT

The relationship between sleep duration trajectories and cognitive decline remains uncertain. This study aims to examine the connections between various patterns of sleep duration and cognitive function.

METHODS

Group-based trajectory modeling (GBTM) was employed to identify longitudinal trajectories of sleep duration over four-year follow-up period, while considering age, sex and nap duration as adjustments. Logistic regression was utilized to analyze the association between sleep trajectories and cognition, with odds ratios (OR) and 95 % confidence intervals (CI) reported. Subgroup analyses based on various demographic characteristics were conducted to explore potential differences in sleep trajectories and cognitive decline across different population subgroups.

RESULTS

A total of 5061 participants were followed for four years, and three sleep duration trajectories were identified: high increasing (n = 2101, 41.6 %), stable increasing (n = 2087, 40.7 %), and low decreasing (n = 873, 17.7 %). After adjustment for basic demographic information, health status, and baseline cognition, the high increasing trajectory was found to be associated with cognitive decline in terms of global cognition (OR:1.52,95 %CI:1.18-1.96), mental intactness (OR:1.36,95 %CI:1.07-1.73) and episodic memory (OR:1.33, 95 %CI:1.05-1.67), as compared to stable increasing trajectory. These associations were particularly prominent among the non-elderly population (≤65 years) and those without depressive symptoms.

CONCLUSION

This study suggests that both high increasing and low decreasing sleep duration trajectories are linked to cognitive decline, as compared to the stable increasing trajectory. Long-term attention to changes in sleep duration facilitates early prevention of cognitive decline.

Biomarkers of sleep-wake disturbance as predictors of cognitive decline and accelerated disease progression

INTRODUCTION

In older adults, where sleep disturbances and cognitive impairment are common, mounting evidence suggests a potential connection between sleep and cognitive function, highlighting the significance of utilizing sleep as a biomarker for early detection of cognitive impairment to improve clinical outcomes in a noninvasive, cost-effective manner.

AREAS COVERED

This review describes the relationship between sleep and cognitive function in older adults, encompassing both subjective and objective measures of sleep quality, duration, architecture, and sleep-disordered breathing. The authors consider the directionality of the associations observed in prospective and cross-sectional studies, exploring whether sleep disturbances precede cognitive decline or vice versa. Furthermore, they discuss the potential bidirectional relationships between sleep and Alzheimer's disease (AD) risks in older adults while also examining the neurodegenerative pathways of this relationship.

EXPERT OPINION

Routine sleep monitoring in primary care settings has the potential to bolster early detection and treatment of sleep disturbance, and by extension, reduce the risk of dementia. Improving sleep assessment tools, such as wearables, provide scalable alternatives to traditional methods like polysomnography, potentially enabling widespread monitoring of sleep characteristics. Standardized measurement and inclusive participant recruitment are needed to enhance generalizability, while longitudinal studies are essential to understand the interaction between sleep and AD pathology.

Association between sleep duration and subjective memory complaints: A large-scale cross-sectional study based on NHANES

Objective

When chatting, people often forget what they want to say, that is, they suffer from subjective memory complaints (SMCs). This research examines the Association between sleep duration and self-reported SMC in a sample representing the entire United States.

Methods

We examined data from 5567 individuals (aged 20-80) who participated in the National Health and Nutrition Examination Survey (2015-2018) to evaluate the association between sleep duration and SMC. Odds ratios (ORs) and a restricted cubic spline (RCS) curve were calculated with multiple logistic regression, and subgroup analysis was performed.

Results

Approximately 5.8 % (3 2 3) reported SMC, and most are older people (1 6 3). RCS analysis treating sleep duration as a continuous variable revealed a J-shaped curve association between sleep duration and SMC. Self-reported sleep duration was significantly linked to a 33 % elevated risk of SMC (OR, 1.33; 95 % confidence interval [CI], 1.23-1.43; P < 0.001). In the group analysis, individuals who slept more than 8 h per day had a greater association of experiencing SMC than those who slept for 6-8 h/day (OR, 1.75; 95 % CI, 1.36-2.23; P < 0.001). In the analysis of age groups, the stable association between sleep duration and SMC was observed only in the 60-80 age bracket (OR, 1.59; 95 % CI, 1.09-2.33; P < 0.001).

Conclusions

We found that people with self-report sleep duration exceeding 8 h are more likely to experience SMC, especially older adults. Improving sleep health may be an effective strategy for preventing SMC and cognitive impairment.

The association between sleep duration, bedtime, and cognitive ability in Chinese adults: Evidence from the China family panel studies

Introduction

Dementia is marked by a steady decline or worsening in cognitive abilities, affecting memory, logic, and social competencies. While many studies suggest a potential link between the amount of sleep and dementia risk, the outcomes are not yet consistent. This research delved into the relationship between sleep length and bedtime on cognitive abilities using an extensive dataset from the China Family Panel Studies (CFPS) from 2014 to 2020.

Methods

Data from 175,702 observations were collected, including cognitive function test data from 22,848 participants. Various cognitive tests were used to assess cognitive function. Restricted cubic spline (RCS) models were used for data analysis.

Results

The optimal sleep duration for cognitive function was found to be 6-7 h, and the optimal bedtime was generally between 22:00-23:00. Longitudinal analysis revealed that sleep duration four years prior had a significant impact on current cognitive function. After accounting for various factors, those who slept for 7-8 h and over 8 h displayed lower cognitive function scores. Conversely, individuals sleeping less than 6 h had higher scores on the Vocabulary Test. Bedtime before 22:00 was associated with lower scores on the Vocabulary Test and Mathematical Test. Subgroup analyses based on age, gender, and urban residence showed variations in optimal sleep duration for different populations. Propensity Score Matching (PSM) analysis supported the findings.

Conclusions

Maintaining a sleep duration of 6-7 h and a regular bedtime between 22:00-23:00 is important for optimizing cognitive performance.

Comparative efficacy of non-pharmacological interventions on sleep quality in old adults: A systematic review and network meta-analysis

AIMS AND OBJECTIVES

To compare the effectiveness of non-pharmacological interventions in enhancing sleep quality in older people.

BACKGROUND

Sleep problems in older adults have become increasingly prominent. Sleep problems not only affect the health and quality of life of older people, but also the range of chronic diseases caused by sleep problems also impose a huge burden on social services and health care. Non-pharmacological interventions are an effective alternative to pharmacological therapies, but it is unclear which non-pharmacological therapies are most effective in enhancing sleep quality in older adults.

DESIGN

A systematic review and network meta-analysis based on PRISMA-NMA.

METHODS

A total of seven databases were searched from the establishment of the database to March 2023. After literature screening and data extraction, the Cochrane Bias assessment tool 2.0 version of randomised controlled trials (RCTs) was used to evaluate literature quality. A network meta-analysis was performed to evaluate the relative efficacy of the non-pharmacological interventions on sleep quality.

RESULTS

A total of 71 RCTs involving nine non-pharmacological interventions were included. The results of the network meta-analysis showed that the joint intervention may be the most effective non-pharmacological intervention to enhance sleep quality in older adults.

CONCLUSION

This study confirms that non-pharmacological interventions can improve sleep quality in older adults. The use of non-pharmacological interventions can be promoted by healthcare professionals in the future to improve the quality of sleep and thus the physical and mental health of older people.

RELEVANCE TO CLINICAL PRACTICE

This evidence suggests that joint interventions may be most effective. Therefore, in the future, a combination of non-pharmacological interventions could be used to maximise their effectiveness in improving sleep quality in older people and promoting healthy aging.

NO PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution is not applicable to this study.

Sleep duration, insomnia and cognitive performance in the Elsa-Brasil cohort: a cross-sectional analysis

OBJECTIVE

To investigate the single and combined associations between sleep disturbances (sleep duration, insomnia symptoms in the last 30 nights, and daytime tiredness) and performance in cognitive tests.

METHODS

Cross-sectional analysis of data from visit 2 (2012-2014) of the Longitudinal Study of Adult Health from a cohort of active and retired civil servants from six Brazilian capitals. Polynomial regression with quadratic term and multiple linear regression models were performed to assess single and combined associations between sleep disturbances and memory performance, fluency, executive functions, and global cognition.

RESULTS

A total of 7,248 participants were included, with a mean age of 62.7 years (standard deviation [SD]=5.9), and 55.2% were women. Inverted U-shaped associations were observed between sleep duration and performance on all cognitive abilities, suggesting that durations shorter or longer than seven hours are associated with worse performance, regardless of age. Reported insomnia was associated with worse executive function (β: -0.08; 95% confidence interval [CI]: -0.15 to -0.01), and the magnitudes of associations were higher for individuals with insomnia at two or more moments (β: -0.12; 95%CI -0.19 to -0.05) or, especially, insomnia combined with short sleep (β: -0.18; 95%CI -0.24 to -0.11). Insomnia in two or more periods was also associated with lower memory and global cognition. There was no association between any sleep disturbance tested and verbal fluency. Isolated daytime tiredness was not associated with performance in the evaluated tests.

CONCLUSION

The results suggest that extreme sleep durations are detrimental to almost all cognitive abilities investigated, whereas insomnia appears to affect more severely the executive function.

Investigating the association between a history of depression and biomarkers of Alzheimer's disease, cerebrovascular disease, and neurodegeneration in patients with dementia

The association between depression and dementia, particularly Alzheimer's disease (AD) and cerebrovascular disease (CVD), remains an active area of research. This study aimed to investigate the relationship between a history of depression and biomarkers of AD and CVD in patients with dementia in a clinical setting. A total of 126 patients from the University Health Network (UHN) Memory Clinic with comprehensive clinical evaluations, including neuropsychological testing and medical examinations, were included. Lumbar puncture was performed to collect cerebrospinal fluid (CSF) for biomarker analysis, and brain magnetic resonance imaging (MRI) scans were obtained to assess white matter hyperintensity (WMH) burden. The presence of depression was determined through medical records. The study findings did not reveal significant differences between participants with and without a history of depression in terms of AD biomarkers, WMH burden, neurofilament light chain levels, cognitive scores, age of symptom onset, disease duration, or vascular risk scores. Logistic regression analysis did not indicate a meaningful predictive value of these variables for depression status. This clinical study contributes to our understanding regarding the association between depression and AD/CVD biomarkers in patients with cognitive impairment. Further research is needed to elucidate the complex relationship between depression and dementia and to explore the potential mechanisms linking depression, AD, and CVD.

Associations of sleep duration and daytime sleepiness with plasma amyloid beta and cognitive performance in cognitively unimpaired, middle-aged and older African Americans

STUDY OBJECTIVES

Given the established racial disparities in both sleep health and dementia risk for African American populations, we assess cross-sectional and longitudinal associations of self-report sleep duration (SRSD) and daytime sleepiness with plasma amyloid beta (Aβ) and cognition in an African American (AA) cohort.

METHODS

In a cognitively unimpaired sample drawn from the African Americans Fighting Alzheimer's in Midlife (AA-FAiM) study, data on SRSD, Epworth Sleepiness Scale, demographics, and cognitive performance were analyzed. Aβ40, Aβ42, and the Aβ42/40 ratio were quantified from plasma samples. Cross-sectional analyses explored associations between baseline predictors and outcome measures. Linear mixed-effect regression models estimated associations of SRSD and daytime sleepiness with plasma Aβ and cognitive performance levels and change over time.

RESULTS

One hundred and forty-seven participants comprised the cross-sectional sample. Baseline age was 63.2 ± 8.51 years. 69.6% self-identified as female. SRSD was 6.4 ± 1.1 hours and 22.4% reported excessive daytime sleepiness. The longitudinal dataset included 57 participants. In fully adjusted models, neither SRSD nor daytime sleepiness is associated with cross-sectional or longitudinal Aβ. Associations with level and trajectory of cognitive test performance varied by measure of sleep health.

CONCLUSIONS

SRSD was below National Sleep Foundation recommendations and daytime sleepiness was prevalent in this cohort. In the absence of observed associations with plasma Aβ, poorer self-reported sleep health broadly predicted poorer cognitive function but not accelerated decline. Future research is necessary to understand and address modifiable sleep mechanisms as they relate to cognitive aging in AA at disproportionate risk for dementia.

CLINICAL TRIAL INFORMATION

Not applicable.

Gender-and age-specific associations of sleep duration and quality with cognitive impairment in community-dwelling older adults in Anhui Province, China

Objective

To examine associations of sleep duration and quality with cognitive impairment in older adults and the moderating role of gender and age in these associations.

Methods

This community-based cross-sectional study included 4,837 participants aged 60 years and above. Cognitive function was assessed using the Chinese version of the Mini-Mental State Examination (MMSE), and the participants were grouped based on the presence of cognitive impairment. The duration and quality of sleep were assessed using the Pittsburgh Sleep Quality Index (PSQI). Multivariate logistic regression models were used to analyze associations of sleep duration and quality with cognitive impairment. The role of age and gender in these associations have also been explored.

Results

The age (mean ± SD) of the participants was 71.13 ± 5.50 years. Of all older adults, 1,811 (37.44%) were detected as cognitive impairment, and 1755 (36.8%) had poor sleep quality. Among those with cognitive impairment, 51.09% were female. The proportion of the participants with cognitive impairment is significantly higher in those with symptoms of depression (49.73%, 273/549) (χ2 = 41.275, p < 0.001) than in those without depressive symptoms. After adjustment for multiple confounding factors and the crucial covariate (depressive symptoms), the odds ratios (OR) (95% confidence interval [CI]) of cognitive impairment (with 7-7.9 h regarded as the reference group) for individuals with a sleep duration of <6, 6-6.9, 8-8.9, and ≥ 9 h were 1.280 (1.053-1.557), 1.425 (1.175-1.728), 1.294 (1.068-1.566), and 1.360 (1.109-1.668), respectively. Subgroup analysis showed a V-shaped association between night sleep duration and cognitive impairment in males (p ≤ 0.05), and the association was stronger for individuals aged 60-80 years. With regard to sleep quality, the fully adjusted OR (95%CI) of cognitive impairment were 1.263 (1.108-1.440). According to scores of subscales in the PSQI, daytime dysfunction was associated with an increased risk of cognitive impairment (OR: 1.128, 95%CI: 1.055-1.207). Subgroup analysis also revealed a statistically significant correlation between poor sleep quality (including daytime dysfunction) and cognitive impairment in different gender and age groups, with the association being stronger in females (OR: 1.287, 95%CI: 1.080-1.534) and those aged 81-97 years (OR: 2.128, 95%CI: 1.152-3.934). For cognitive impairment, the group aged 81-97 years with daytime dysfunction was associated with a higher odds ratio than other age groups.

Conclusion

The present study showed that inadequate or excessive sleep was associated with cognitive impairment, especially in males, who exhibited a V-shaped association. Cognitive impairment was also associated with poor sleep quality as well as daytime dysfunction, with females and individuals aged 81-97 years exhibiting the strongest association.

Sleep Duration and Executive Function in Adults

PURPOSE OF REVIEW

To review the literature examining the relationship between sleep and cognition, specifically examining the sub-domain of executive function. We explore the impact of sleep deprivation and the important question of how much sleep is required for optimal cognitive performance. We consider how other sleep metrics, such as sleep quality, may be a more meaningful measure of sleep. We then discuss the putative mechanisms between sleep and cognition followed by their contribution to developing dementia.

RECENT FINDINGS

Sleep duration and executive function display a quadratic relationship. This suggests an optimal amount of sleep is required for daily cognitive processes. Poor sleep efficiency and sleep fragmentation are linked with poorer executive function and increased risk of dementia during follow-up. Sleep quality may therefore be more important than absolute duration. Biological mechanisms which may underpin the relationship between sleep and cognition include brain structural and functional changes as well as disruption of the glymphatic system. Sleep is an important modifiable lifestyle factor to improve daily cognition and, possibly, reduce the risk of developing dementia. The impact of optimal sleep duration and sleep quality may have important implications for every ageing individual.

The influence of baseline sleep on exercise-induced cognitive change in cognitively unimpaired older adults: A randomised clinical trial

OBJECTIVES

Observational studies consistently demonstrate that physical activity is associated with elevated cognitive function, however, there remains significant heterogeneity in cognitive outcomes from randomized exercise interventions. Individual variation in sleep behaviours may be a source of variability in the effectiveness of exercise-induced cognitive change, however this has not yet been investigated. The current study aimed to (1) investigate the influence of a 6-month exercise intervention on sleep, assessed pre- and post-intervention and, (2) investigate whether baseline sleep measures moderate exercise-induced cognitive changes.

METHODS

We utilised data from the Intense Physical Activity and Cognition (IPAC) study (n = 89), a 6-month moderate intensity and high intensity exercise intervention, in cognitively unimpaired community-dwelling older adults aged 60-80 (68.76 ± 5.32). Exercise was supervised and completed on a stationary exercise bicycle, and cognitive function was measured using a comprehensive neuropsychological battery administered pre- and post-intervention. Sleep was measured using the Pittsburgh sleep quality index. There was no effect of the exercise intervention on any sleep outcomes from pre- to post-intervention.

RESULTS

There was a significant moderating effect of baseline sleep efficiency on both episodic memory and global cognition within the moderate intensity exercise group, such that those with poorer sleep efficiency at baseline showed greater exercise-induced improvements in episodic memory.

CONCLUSIONS

These results suggest that those with poorer sleep may have the greatest exercise-induced cognitive benefits and that baseline sleep behaviours may be an important source of heterogeneity in previous exercise interventions targeting cognitive outcomes.

The association of previous night's sleep duration with cognitive function among older adults: a pooled analysis of three Finnish cohorts

STUDY OBJECTIVES

Sleep duration has been shown to associate with cognitive function, but little is known about the short-term effect of sleep duration on the previous night. This study examines how usual sleep duration and previous night's sleep duration are associated with cognitive function in older adults.

METHODS

The study population consisted of 2949 adults aged 59-92 years (mean 72.6, SD 5.7) derived from three Finnish cohorts. Participants' self-reported usual sleep duration was categorized into short (< 7 h, 19%), mid-range (7- < 9 h, 64%), and long (≥ 9 h, 17%). Self-reported sleep duration on the night prior to cognitive testing was categorized into shorter (59%), same (35%), and longer (5.9%) than usual sleep duration. Computerized Cambridge Neuropsychological Test Automated Battery (CANTAB®) was used to assess: (1) learning and memory, (2) working memory, (3) information processing, and (4) reaction time.

RESULTS

Participants with self-reported long, but not short, usual sleep duration had poorer learning and memory (p = .004), information processing (p = .003), and reaction time (p = .006) when compared to those with mid-range sleep duration. Those who slept more than usually the night prior to cognitive testing had poorer information processing (p = .019) than those sleeping the same as usually, while sleeping less than usually was not associated with cognitive function.

CONCLUSIONS

This study suggests that while long sleep duration was associated with worse cognitive function, sleeping more than usually the night prior to cognitive testing was only associated with information processing, and sleeping less than usually is not associated with cognitive function.

Relationship between self-reported sleep and cognitive function: a specification curve analysis

The relationship between self-reported sleep and cognitive function is complex; it is unclear whether self-reported sleep is a robust correlate of people's cognitive function. We address this gap by using a comprehensive large-scale dataset (N = 1054) coupled with a novel modeling approach, specification curve analysis (SCA), to test the association between self-reported sleep and cognitive function. The results of the SCA showed robust correlations between self-reported sleep and cognitive function, with poorer sleep associated with worse cognitive function. Furthermore, the correlations between sleep components and cognitive function were heterogeneous, with differences emerging across cognitive measures and domains. Specifically, daytime dysfunction was associated with the strongest effect on subjective cognitive function, whereas sleep duration and sleep efficiency had the strongest effect on objective cognitive function. Therefore, the relationship between self-reported sleep and cognition depends largely on what and how cognitive function is measured. Our findings guide measurement and domain selection for future research on the role of sleep in cognitive function.

The Relationship Between Social Capital and Sleep Duration Among Older Adults in Ghana: A Cross-Sectional Study

Objective: This study aims to investigate the connection between social capital and sleep duration among older adults in Ghana, as limited research has been conducted to explore this relationship. Methods: This study utilized Wave 2 data from a sample of Ghanaian older adults from the World Health Organization Study on Global AGEing and Adult Health (SAGE). Self-reported data on social capital and sleep duration were compiled. Using ordered logistic regression, the relationship between social capital and sleep duration was examined. Results: Older adults who did not participate in social activities showed the strongest association with the risk of short sleep (p < 0.05). Our study found that older adults who sleep for shorter periods tend to report better sleep quality. There was no correlation between medium and long sleep durations and social capital. Conclusion: This study underscores the importance of more research to truly understand the complex connections between older adults' social participation, sleep, and health. It also has important implications for the promotion of good sleep in aging populations.

Sleep quality differentially modulates neural oscillations and proteinopathy in Alzheimer's disease

BACKGROUND

Alterations in resting-state neural activity have been reported in people with sleep disruptions and in patients with Alzheimer's disease, but the direct impact of sleep quality on Alzheimer's disease-related neurophysiological aberrations is unclear.

METHODS

We collected cross-sectional resting-state magnetoencephalography and extensive neuropsychological and clinical data from 38 biomarker-confirmed patients on the Alzheimer's disease spectrum and 20 cognitively normal older control participants. Sleep efficiency was quantified using the Pittsburgh Sleep Quality Index.

FINDINGS

Neural activity in the delta frequency range was differentially affected by poor sleep in patients on the Alzheimer's disease spectrum. Such neural changes were related to processing speed abilities and regional amyloid accumulation, and these associations were mediated and moderated, respectively, by sleep quality.

INTERPRETATION

Together, our results point to a mechanistic role for sleep disturbances in the widely reported neurophysiological aberrations seen in patients on the Alzheimer's disease spectrum, with implications for basic research and clinical intervention.

FUNDING

National Institutes of Health, USA.

Sleep, physical activity, and sedentary behaviors as factors related to depression and health-related quality of life among older women living alone: a population-based study

BACKGROUND

Although the number of older women living alone (OWLA) has risen steadily in aging societies, and research has been conducted on depression and health-related quality of life (HRQoL) among older adults, research is scarce on the health behaviors of OWLA, including their sleep, physical activity, and sedentary behaviors. Hence, we aimed to identify factors related to depression and HRQoL among this subset of the population, focusing on their health behaviors, using Andersen's model as a research framework.

METHODS

Data for secondary analysis were from the Korean National Health and Nutritional Examination Survey (2014, 2016, 2018, and 2020). The inclusion criteria were (1) women aged 65 and older and (2) those living alone. We included 794 older South Korean women living alone from 31,051 respondents. We used hierarchical regression analysis, considering sampling weight and a complex sample design, to identify factors related to depression and HRQoL.

RESULTS

Among the health behavior factors of Andersen's model as a research framework, sleep was associated with depression, whereas physical activity and sedentary behaviors were related to HRQoL. Subjective health status, limited activity, and perceived stress were associated with both depression and HRQoL. Household income, as an enabling factor, was only associated with HRQoL. The final regression model explained 39% of the variance in depression (p < 0.001) and 37% of the variance in HRQoL (p < 0.001).

CONCLUSIONS

Our study highlights the importance of strategies to improve specific healthy behaviors that affect depression and HRQoL in OWLA. Appropriate interventions that target increasing physical activity and quality of sleep, and decreasing sedentary behaviors, will be effective to enhance the well-being of OWLA. Healthcare providers should comprehensively understand the characteristics of OWLA and pay more attention to enabling, need, and health behavior factors.

Can afternoon napping protect against the negative effect of short or long sleep duration on cognitive function? A prospective study

OBJECTIVES

Afternoon napping has been found to be able to compensate for the negative health effects of less optimal nighttime sleep duration. Our study aimed to investigate whether napping can protect against the negative effects of short or long sleep duration on cognitive function among middle-aged and older adults.

METHODS

A total of 8107 participants (men, 53.19%) aged 45 and older from the China Health and Retirement Longitudinal Study were followed prospectively for 7 years. The primary outcome was cognitive function (episodic memory and mental status). Afternoon napping was categorized into three groups including non- (0 min), moderate (1-30 min) and long (>30 min) duration. Nighttime sleep was also categorized into three groups including short (<7 h), normal (7-8 h), and long (>8 h) duration. Linear mixed models were used with napping and sleep duration at baseline as predictors. Potential confounders including baseline cognitive function were adjusted.

RESULTS

Shorter sleep duration (B = -0.01, p = 0.048) was independently associated with a faster decline in episodic memory. For participants with shorter sleep duration, either non-napping (B = -0.03, p = 0.017) or longer napping (B = -0.04, p = 0.018) showed a significant decline of episodic memory. For participants with longer sleep duration, non-napping was associated with a significant decline of episodic memory (B = -0.07, p = 0.003).

CONCLUSIONS

This study found that moderate napping could protect against the negative effects of short or long sleep duration on episodic memory, which implied that middle-aged and older adults who have a less optimal sleep duration might benefit from moderate napping for their cognitive function.

Understanding the Need for Sleep to Improve Cognition

The restorative function of sleep is shaped by its duration, timing, continuity, subjective quality, and efficiency. Current sleep recommendations specify only nocturnal duration and have been largely derived from sleep self-reports that can be imprecise and miss relevant details. Sleep duration, preferred timing, and ability to withstand sleep deprivation are heritable traits whose expression may change with age and affect the optimal sleep prescription for an individual. Prevailing societal norms and circumstances related to work and relationships interact to influence sleep opportunity and quality. The value of allocating time for sleep is revealed by the impact of its restriction on behavior, functional brain imaging, sleep macrostructure, and late-life cognition. Augmentation of sleep slow oscillations and spindles have been proposed for enhancing sleep quality, but they inconsistently achieve their goal. Crafting bespoke sleep recommendations could benefit from large-scale, longitudinal collection of objective sleep data integrated with behavioral and self-reported data.

Twenty-four-hour time-use composition and cognitive function in older adults: Cross-sectional findings of the ACTIVate study

Introduction

Physical activity, sedentary behaviour and sleep are associated with cognitive function in older adults. However, these behaviours are not independent, but instead make up exclusive and exhaustive components of the 24-h day. Few studies have investigated associations between 24-h time-use composition and cognitive function in older adults. Of these, none have considered how the quality of sleep, or the context of physical activity and sedentary behaviour may impact these relationships. This study aims to understand how 24-h time-use composition is associated with cognitive function across a range of domains in healthy older adults, and whether the level of recreational physical activity, amount of television (TV) watching, or the quality of sleep impact these potential associations.

Methods

384 healthy older adults (age 65.5 ± 3.0 years, 68% female, 63% non-smokers, mean education = 16.5 ± 3.2 years) participated in this study across two Australian sites (Adelaide, n = 207; Newcastle, n = 177). Twenty-four-hour time-use composition was captured using triaxial accelerometry, measured continuously across 7 days. Total time spent watching TV per day was used to capture the context of sedentary behaviours, whilst total time spent in recreational physical activity was used to capture the context of physical activity (i.e., recreational accumulation of physical activity vs. other contexts). Sleep quality was measured using a single item extracted from the Pittsburgh Sleep Quality Index. Cognitive function was measured using a global cognition index (Addenbrooke's Cognitive Examination III) and four cognitive domain composite scores (derived from five tests of the Cambridge Neuropsychological Test Automated Battery: Paired Associates Learning; One Touch Stockings of Cambridge; Multitasking; Reaction Time; Verbal Recognition Memory). Pairwise correlations were used to describe independent relationships between time use variables and cognitive outcomes. Then, compositional data analysis regression methods were used to quantify associations between cognition and 24-h time-use composition.

Results

After adjusting for covariates and false discovery rate there were no significant associations between time-use composition and global cognition, long-term memory, short-term memory, executive function, or processing speed outcomes, and no significant interactions between TV watching time, recreational physical activity engagement or sleep quality and time-use composition for any cognitive outcomes.

Discussion

The findings highlight the importance of considering all activities across the 24-h day against cognitive function in older adults. Future studies should consider investigating these relationships longitudinally to uncover temporal effects.

Evaluation of an occupation-based sleep program for people with Insomnia

Background

Sleep problems are a health issue worldwide. Based on the Person-Environment-Occupation-Performance model, we developed an occupation-based sleep programme to promote awareness of sleep hygiene factors, promote an environment conductive to sleep, and restructure participation in daytime activities with a focus on occupational balance.

Method

This study uses a non-equivalent group design to evaluate the effectiveness of an occupation-based sleep intervention among community-dwelling adults with insomnia, when compared with a treatment-as-usual (TAU) group which focused on sleep hygiene, and relaxation.

Results

When compared with the TAU group ( n = 20), the intervention group ( n = 22) had significant improvement in sleep duration, occupational balance, and reduction in mood symptoms at both post treatment and 1-month follow up.

Conclusion

The results demonstrated that an occupation-based programme is an effective treatment for insomnia disorder and demonstrated the role which occupational therapy could play in primary health care service.

Does sleep duration moderate genetic and environmental contributions to cognitive performance?

While prior research has demonstrated a relationship between sleep and cognitive performance, how sleep relates to underlying genetic and environmental etiologies contributing to cognitive functioning, regardless of the level of cognitive function, is unclear. The present study assessed whether the importance of genetic and environmental contributions to cognition vary depending on an individual's aging-related sleep characteristics. The large sample consisted of twins from six studies within the Interplay of Genes and Environment across Multiple Studies (IGEMS) consortium spanning mid- to late-life (Average age [Mage] = 57.6, range = 27-91 years, N = 7052, Female = 43.70%, 1525 complete monozygotic [MZ] pairs, 2001 complete dizygotic [DZ] pairs). Quantitative genetic twin models considered sleep duration as a primary moderator of genetic and environmental contributions to cognitive performance in four cognitive abilities (Semantic Fluency, Spatial-Visual Reasoning, Processing Speed, and Episodic Memory), while accounting for age moderation. Results suggested genetic and both shared and nonshared environmental contributions for Semantic Fluency and genetic and shared environmental contributions for Episodic Memory vary by sleep duration, while no significant moderation was observed for Spatial-Visual Reasoning or Processing Speed. Results for Semantic Fluency and Episodic Memory illustrated patterns of higher genetic influences on cognitive function at shorter sleep durations (i.e. 4 hours) and higher shared environmental contributions to cognitive function at longer sleep durations (i.e. 10 hours). Overall, these findings may align with associations of upregulation of neuroinflammatory processes and ineffective beta-amyloid clearance in short sleep contexts and common reporting of mental fatigue in long sleep contexts, both associated with poorer cognitive functioning.

Six nights of sleep extension increases regional cerebral oxygenation without modifying cognitive performance at rest or following acute aerobic exercise

Long sleep durations (≥540 min) are associated with poor cognitive performance in ageing adults, but the underlying cause is unclear. The aim of this study was to investigate the effect of extended sleep on cognitive performance and cerebral vascular function before and then after aerobic exercise. In all, 12 adults completed 6 nights of 8- (control) and 10+-h (sleep extension) time in bed in a randomised, crossover experiment. Sleep was measured using wrist actigraphy. On the last day of each time in bed protocol, participants performed three bouts of brisk walking. Sustained attention, spatial rotation ability, mental flexibility, and working memory were assessed, while prefrontal oxygen saturation index (ΔTSI) was measured using near-infrared spectroscopy. A two-way repeated-measures analysis of variance (time in bed × before/after exercise) was used for statistical analysis. Average sleep duration was longer following sleep extension as compared to control, at a mean (SD) of 551 (16) versus 428 (20) min (p < 0.001). Sleep extension did not alter cognitive performance as compared to control, but increased ΔTSI during tests of spatial rotation ability (main effect for time in bed, p = 0.03), mental flexibility (p = 0.04), and working memory (p < 0.01). Cognitive performance was improved (main effect for exercise, p < 0.05) following brisk walking for all cognitive domains except sustained attention with no interaction with time in bed. In summary, 6 nights of extended time in bed accompanied by long sleep durations does not impair cognitive performance at rest or alter the positive effect of acute aerobic exercise on cognition but may increase frontal cerebral oxygenation during cognitive functioning.

Does total sleep time substantially increase after cognitive behavioral therapy for insomnia?

STUDY OBJECTIVES

In most standardized approaches to cognitive behavioral therapy for insomnia, it is commonly the case that total wake time is reduced substantially during sleep restriction, but self-reported total sleep time (TST) is minimally affected. By follow-up, however, TST increases by almost 1 hour on average. A secondary analysis was undertaken to assess what percentage of participants meet or appreciably exceed baseline TST after cognitive behavioral therapy for insomnia.

METHODS

Data were drawn from a randomized controlled trial assessing acute and maintenance therapies for chronic insomnia (n = 80). The present analyses assessed the percentage of participants that 1) reached (≥ 0 minute increase) and 2) appreciably exceeded (≥ 30 minutes increase) baseline TST as assessed via daily sleep diaries at posttreatment and 3, 6, 12, and 24 months following treatment.

RESULTS

By the end of acute treatment, 45% of participants reached or exceeded baseline TST. By 24 months follow-up, this percentage had increased to 86%. Only 17% of participants achieved a 30-minute increase in TST by the end of acute treatment, and this proportion only increased to 58% over time.

CONCLUSIONS

These findings suggest that cognitive behavioral therapy for insomnia in its current form does not appreciably increase self-reported TST in a significant proportion of patients with insomnia. Whether participants would benefit from further increases in TST warrants investigation. The further titration of sleep opportunity may be useful to accelerate increases in TST, to extend the effect to a larger subset of patients, and/or to increase the magnitude of the TST gain.

CITATION

Scott H, Cheung JMY, Muench A, et al. Does total sleep time substantially increase after cognitive behavioral therapy for insomnia? J Clin Sleep Med. 2022;18(7):1823-1829.

Sex Modified the Association between Sleep Duration and worse Cognitive Performance in Chinese Hypertensive Population: Insight from the China H-Type Hypertension Registry Study

Objectives

Cognitive decline could be seen as the sign of preclinical phase of dementia, which was found to be sex differentiated. Previous studies had discovered that there might be some link between abnormal sleep duration and cognitive performance. Additionally, hypertension was found to be one of the important risk factors for cognitive decline and abnormal sleep duration was also a significant risk factor for hypertension. Therefore, the purpose of this study was to investigate sex differences in the association of sleep duration with cognitive performance and to further explore potential effect modifiers that may exist.

Methods

Data analyzed in this study was from the China H-type Hypertension Registry Study. Sleep duration was assessed with a sleep questionnaire and categorized as <5 hours, 5-8 hours, and ≥8 hours. Cognitive performance was evaluated with the Mini-Mental State Examination (MMSE).

Result

A total of 9527 subjects were included. The average age was 63.7 ± 9.8 years. Linear regression analyses showed that the association between long sleep duration (≥8 h) and MMSE score adjusting for pertinent covariables was stronger in female (β = −0.95, 95% CI: -1.23 to -0.68, P < 0.001) than in male (β = −0.29, 95% CI: -0.53 to -0.06, P = 0.013). Furthermore, there was a significant interaction between sleep duration and age on cognitive performance only in female.

Conclusion

In summary, this study found that long sleep duration (≥8 h) was associated with poorer cognitive performance. Furthermore, this association was more pronounced in female than in male, especially in older female.

Thirteen Independent Genetic Loci Associated with Preserved Processing Speed in a Study of Cognitive Resilience in 330,097 Individuals in the UK Biobank

Cognitive resilience is the ability to withstand the negative effects of stress on cognitive functioning and is important for maintaining quality of life while aging. The UK Biobank does not have measurements of the same cognitive phenotype at distal time points. Therefore, we used education years (EY) as a proxy phenotype for past cognitive performance and current cognitive performance was based on processing speed. This represented an average time span of 40 years between past and current cognitive performance in 330,097 individuals. A confounding factor was that EY is highly polygenic and masked the genetics of resilience. To overcome this, we employed Genomics Structural Equation Modelling (GenomicSEM) to perform a genome-wide association study (GWAS)-by-subtraction using two GWAS, one GWAS of EY and resilience and a second GWAS of EY but not resilience, to generate a GWAS of Resilience. Using independent discovery and replication samples, we found 13 independent genetic loci for Resilience. Functional analyses showed enrichment in several brain regions and specific cell types. Gene-set analyses implicated the biological process "neuron differentiation", the cellular component "synaptic part" and the "WNT signalosome". Mendelian randomisation analysis showed a causative effect of white matter volume on cognitive resilience. These results may contribute to the neurobiological understanding of resilience.

Self-reported sleep characteristics associated with dementia among rural-dwelling Chinese older adults: a population-based study

BACKGROUND

Sleep characteristics associated with dementia are poorly defined and whether their associations vary by demographics and APOE genotype among older adults are unclear.

METHODS

This population-based cross-sectional study included 4742 participants (age ≥ 65 years, 57.1% women) living in rural China. Sleep parameters were measured using the self-rated questionnaires of the Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale. Global cognitive function was assessed with the Mini-Mental State Examination (MMSE). Dementia was diagnosed following the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, and the National Institute on Aging-Alzheimer's Association criteria for Alzheimer's disease (AD). Data were analysed using multiple logistic and general linear regression models.

RESULTS

Dementia was diagnosed in 173 participants (115 with AD). Multivariable-adjusted odds ratio (OR) of dementia was 1.71 (95%CI, 1.07-2.72) for sleep duration ≤4 h/night (vs. > 6-8 h/night), 0.76 (0.49-1.18) for > 4-6 h/night, 1.63 (1.05-2.55) for > 8 h/night, 1.11 (1.03-1.20) for lower sleep efficiency (per 10% decrease), and 1.85 (1.19-2.89) for excessive daytime sleepiness. Very short sleep duration (≤4 h/night), lower sleep efficiency, and excessive daytime sleepiness were significantly associated with being diagnosed with AD (multivariable-adjusted OR range = 1.12-2.07; p < 0.05). The associations of sleep problems with dementia and AD were evident mainly among young-old adults (65-74 years) or APOE ε4 carriers. Among dementia-free participants, these sleep characteristics were significantly associated with a lower MMSE score.

CONCLUSIONS

Self-reported sleep problems in dementia are characterized by very short or long sleep duration, low sleep efficiency, and excessive daytime sleepiness, especially among young-old people and APOE ε4 carriers.

TRIAL REGISTRATION

ChiCTR1800017758 (Aug 13, 2018).

The role of orexin in Alzheimer disease: From sleep-wake disturbance to therapeutic target

Accumulating evidence has shown that sleep disturbance is a common symptom in Alzheimer's disease (AD), which is regarded as a modifiable risk factor for AD. Orexin is a key modulator of the sleep-wake cycle and has been found to be dysregulated in AD patients. The increased orexin in cerebrospinal fluid (CSF) is associated with decreased sleep efficiency and REM sleep, as well as cognitive impairment in AD patients. The orexin system has profuse projections to brain regions that are implicated in arousal and cognition and has been found to participate in the progression of AD pathology. Conversely the orexin receptor antagonists are able to consolidate sleep and reduce AD pathology. Therefore, improved understanding of the mechanisms linking orexin system, sleep disturbance and AD could make orexin receptor antagonists a promising target for the prevention or treatment of AD.

Gender-specified mediation of depression between sleep quality and short-term memory in older adults: Study in a semi-closed Island of Xiamen, China

BACKGROUND

Both the quality of sleep and depression impact short-term memory (STM) while they influence each other. However, the underlying mechanisms are not yet clear. Herein, we aimed to explore the mediating effect of depression between sleep quality and STM in older adults and further test the gender differences in this relationship.

METHODS

A cluster sampling survey was carried out among 903 residents that were aged 60+ years in a semi-closed island of Xiamen, China, in 2019. The subjects' sleep quality and depression were measured using the Pittsburgh Sleep Quality Index (PSQI) and the 15-item Geriatric Depression Scale (GDS-15), respectively. The three-item recall test was utilized to measure STM function. Mediation analyses were performed using the structural equation model and bias-corrected bootstrap method. Next, the Wald-test was utilized to determine gender differences in the pathway.

RESULTS

Overall, 355 men and 508 women, with a mean age of 69.55 and 70.97, respectively, had valid data on the main variables. Depression was found to mediate the effect of sleep quality on STM (a*b = -0.076, p < 0.05). Interestingly, while this indirect effect existed in the female group (a_f *b_f  = -0.126, p < 0.05), it did not in the male group (a_m *b_m  = 0.017, p = 0.677). The Wald-test indicated no gender differences in the pathway from sleep quality to depression (p = 0.303). However, the pathway from depression to STM function was found to be significantly stronger for females than males (p = 0.0198).

CONCLUSION

Higher sleep quality was found to be associated with improved STM function. Furthermore, the association was found to be regulate indirectly by lower depressive symptoms for females, but directly for males. Therefore, appropriate psychological interventions may be beneficial to the maintenance of STM for older adults, particularly for women.

Sex, Sleep Duration, and the Association of Cognition: Findings from the China Health and Retirement Longitudinal Study

BACKGROUND

We aimed to examine the association between sleep duration and cognitive impairment among elderly Chinese people.

METHODS

generalized linear modeling was used to analyze the baseline data for adults aged 65 years and over (n = 4785) selected from the 2011 China Health and Retirement Longitudinal Study (CHARLS). The two aspects of cognitive impairment assessed in the study were mental status and memory. Sex-stratified logistic regression models were conducted to identify the effect of sleep duration in the different gender groups.

RESULTS

of all the participants, 49.8% were females and 32.5% aged 75 years and over. Of the participants, 59.7% had short sleep duration (<7 h/day), and 9.0% of them had long sleep duration (>8 h/day). Compared to normal sleep duration, long sleep duration was associated with lower mental status scores (β = -0.43, p = 0.001) and lower memory scores (β = -0.26, p = 0.006). Long sleep duration was associated with lower mental status in both men (β = -0.37, p = 0.033) and women (β = -0.46, p = 0.025), however, only in men was long sleep duration found to be associated with low memory scores (β = -0.26, p = 0.047).

CONCLUSIONS

Our study showed that long sleep duration was significantly associated with poorer mental status and memory scores in elderly Chinese people. Paying greater attention to the effects of sleep patterns on the risk of cognitive decline may yield practical implications for dementia prevention and health promotion, especially among older women with lower educational attainment, living in rural areas, and those who have long sleep duration.

Association of changes in self-reported sleep duration with mild cognitive impairment in the elderly: a longitudinal study

As a symptomatic predementia stage with progressive cognitive decline, mild cognitive impairment (MCI) is common with aging. How changes in self-reported sleep duration affect MCI risk in the older adults remains unclear. Participants aged ≥ 65 years and enrolled at least two waves in the Chinese Longitudinal Healthy Longevity Survey were included in present longitudinal study. Changes in sleep duration were calculated as the difference between two waves and categorized into five groups: decreased >2 h, decreased 0-2h, stable, increased 0-2 h, and increased >2 h. MCI was measured by the Chinese version of the Mini-Mental State Examination. Generalized estimating equation model and restricted cubic spline function was applied to investigate the association. Among 9,005 participants (mean age, 81.19 years; 4,391 male), 2,877 developed MCI. Comparing with individuals with stable sleep duration, MCI risk [odds ratio (95% confidence intervals)] was: 1.15 (0.99-1.34) for decreased >2 h, 0.99 (0.87-1.13) for decreased 0-2h, 1.09 (0.95-1.24) for increased 0-2 h, and 1.57 (1.36-1.81) for increased >2 h, respectively. Similar patterns were observed among subgroup analyses by sex, age, and sleep quality at baseline. For participants with long sleep duration at baseline (>8h), further increased >2 h was associated with higher MCI risk [2.23 (1.55-3.21)]. Either in the whole or subgroup population, a U-shaped association was observed (P_{non-linearity}<0.05). In conclusion, changes in self-reported sleep duration were associated with MCI risk in a U-shaped pattern. Strategies that shifting sleep duration into normal range and keeping it stable are essential to prevent MCI in clinical practice.

Sleep profile predicts the cognitive decline of mild-moderate Alzheimer's disease patients

STUDY OBJECTIVES

To investigate the association between sleep and cognitive decline of patients with mild-moderate Alzheimer's disease.

METHODS

Observational, prospective study, including consecutive patients diagnosed with mild-moderate Alzheimer's disease. Cerebrospinal fluid was collected for amyloid-beta, total-tau, and phospho-tau levels determination. Also, overnight polysomnography was performed, followed by neuropsychological evaluations at baseline and after 12 months of follow-up. Principal component analysis revealed two profiles of patients in terms of sleep: one with a propensity to deepen the sleep (deep sleepers) and the other with a propensity to spend most of the time in the lighter sleep stage (light sleepers).

RESULTS

The cohort included 125 patients with a median [IQR] of 75.0 [72.0;80.0] years. Deep and light sleepers did not present differences in relation to the cerebrospinal fluid pathological markers and to the cognitive function at the baseline. However, there was a significant difference of -1.51 (95% CI: -2.43 to -0.59) in the Mini-mental state examination after 12 months of follow-up. Accordingly, sleep depth and cognitive decline presented a dose-response relationship (p-for-trend = 0.02). Similar outcomes were observed in relation to the processing speed (Stroop words test, p-value = 0.016) and to the executive function (Verbal fluency test, p-value = 0.023).

CONCLUSIONS

Considering the increased cognitive decline presented by light sleepers, the sleep profile may have a predictive role in relation to the cognitive function of patients with mild-moderate Alzheimer's disease. The modifiable nature of sleep sets this behavior as a possible useful intervention to prevent a marked cognitive decline.

Associations between cognitive function, actigraphy-based and self-reported sleep in older community-dwelling adults: Findings from the Irish Longitudinal Study on Ageing

OBJECTIVE

Cognitive impairment is prevalent in older ages. Associations with sleep are well established; however, ambiguity remains in which sleep characteristics contribute to this impairment. We examined cross-sectional associations between both self-reported and actigraphy-based sleep and cognitive performance across a number of domains in community-dwelling older adults.

METHODS

1520 participants aged 50 and older with self-reported and actigraphy-based total sleep time (TST) (≤5, 6, 7-8, 9 and ≥10 h) and self-reported sleep problems were analysed. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), verbal fluency, immediate and delayed recall memory, colour trails tests, and choice reaction tests (CRT). Associations between sleep and cognition were modelled using linear and negative binomial regression.

RESULTS

Negative associations were found between ≥10 h of self-reported TST and MoCA error rate (incidence rate ratio [IRR] = 1.42; 95% confidence interval [CI] = 1.18, 1.71; p < 0.001); verbal fluency (beta [B] = -2.32 words; 95% CI = -4.00, -0.65; p < 0.01); and delayed recall (B = -0.91 words; 95% CI = -1.58, -0.25; p < 0.05) compared to 7-8 h. Significant associations with actigraphy-based TST were limited to MoCA error rate in ≤5 h (IRR = 1.22; 95% CI = 1.02, 1.45; p < 0.05) compared to 7-8 h. Higher numbers of sleep problems were associated with slower performance in CRT cognitive response time (IRR = 1.02; 95% CI = 1.00, 104; p < 0.05) and total response time (IRR = 1.02; 95% CI = 1.00, 1.04; p < 0.05).

CONCLUSIONS

Self-reported long sleep duration was consistently associated with worse cognitive performance across multiple domains. Marginal associations between cognition and both actigraphy-based sleep and self-reported sleep problems were also apparent. These results further affirm poor sleep as a risk factor for cognitive impairment.

Effects of music intervention on sleep quality of older adults: A systematic review and meta-analysis

BACKGROUND

Music interventions have several benefits for sleep quality. However, the effects of music interventions on sleep quality in older adults are controversial.

OBJECTIVE

To summarize and evaluate the efficacy of music interventions on sleep quality in older adults.

METHODS

The Cochrane Library, Embase, PubMed, Web of Science and Chinese National Knowledge Infrastructure (CNKI) were systematically retrieved until June 2020, updated on March 13, 2021. Both experimental and quasi-experimental studies were included if they evaluated the efficacy of music interventions on sleep outcomes in older adults. The methodological quality was assessed by the Cochrane RoB 2.0 and ROBINS-I Tool. The random effects models and effect measure (MD) were adopted, and sensitivity analysis by omitting each study was conducted to explore the source of heterogeneity.

RESULTS

A total of 489 participants from 9 studies met the inclusion criteria. 6 studies were included in meta-analysis and sensitivity analysis, and 3 studies were included in the qualitative analysis. Main concerns about risk of bias were lack of blinding participants and investigators, and confounding factors might exist in non-RCTs. The Post-hoc meta-analysis indicated that music interventions might have a positive effect on sleep quality [MD = -2.64, 95 % CI (-3.76, -1.53), p <  0.001; I² = 75.0 %]. Only one study evaluated adverse events and reported zero discomfort.

CONCLUSIONS

The results indicated that music interventions might be beneficial for improving sleep quality, especially in sleep latency, sleep duration, sleep efficiency and sleep of daytime dysfunction in elderly individuals.

Insomnia as a predictor of diagnosed memory problems: 2006-2016 Health and Retirement Study

OBJECTIVE

To evaluate the longitudinal relationship in insomnia symptoms over time with incident memory problems and dementia diagnoses among U.S. adults aged 65 years and older.

METHODS

Secondary analyses were performed on 9518 elderly participants (≥65 years) who completed the 2006 wave of the Health and Retirement Study (HRS) and were followed-up to determine if insomnia symptom scores (2006-2014) were associated with time-to-onset of [1] physician-diagnosed "memory-related disease", "Alzheimer's disease" and/or "dementia, senility or any other serious memory impairment" and [2] diagnosis of dementia based on HRS-specific criteria. Cox proportional hazards models were constructed adjusting for socio-demographic, lifestyle, and health characteristics.

RESULTS

In fully adjusted models, severe insomnia symptoms were associated with increased risk of physician-diagnosed memory problems. Individuals reporting any change (increase or decrease) in insomnia symptoms during the 2006-2010 period were more likely to be diagnosed with dementia based on HRS criteria. Finally, those who experienced an increase in the severity of insomnia symptoms over time exhibited 41-72% increased risks of physician-diagnosed memory problems and 45-58% increased risks of dementia diagnosis based on HRS criteria.

CONCLUSIONS

When severe insomnia symptoms increased over time, physician-diagnosed memory problems and dementia diagnoses also increased among U.S. elderly people over a 10-year follow-up period. More studies are required to confirm these findings using large prospective cohort designs and validated tools.

Social Network and Risk of Poor Sleep Outcomes in Older Adults: Results from a Spanish Prospective Cohort Study

BACKGROUND

Not having social support has been associated with poor sleep, but most prospective studies were based on social support in the workplace, did not account for baseline sleep characteristics or did not assess sleep duration. Moreover, no previous research has evaluated the relationship between social network and sleep outcomes in an older Spanish population.

METHODS

1444 individuals aged ≥60 years were followed between 2012 and 2015. At baseline (2012), a poor social network index (SNI) was computed by summing the following dichotomous indicators: not being married; living alone; not having daily contact with family, friends or neighbors; being alone ≥8h/day; lacking someone to go for a walk with; not having emotional support; lacking instrumental support. Higher values in SNI indicate less social support. In 2012 and 2015, information was collected on sleep duration (hours/day) and on symptoms of sleep disturbance: bad overall sleep; difficulty falling asleep, awakening during nighttime, early awakening with difficulty getting back to sleep, use of sleeping pills, feeling restless in the morning, being asleep at daytime, and having an Epworth Sleepiness Scale>10. Poor sleep duration was defined as short (<6 h) or long (>9 h) nighttime sleep, and poor sleep quality as having ≥4 indicators of sleep disturbance. Linear or logistic regression models were used to assess the relationship of SNI with changes in sleep duration and in number of sleep disturbance indicators, or with the risk of developing poor nighttime sleep or poor sleep quality.

RESULTS

Compared to individuals in the lowest (best) quartile of the SNI in 2012, those in the second, third and fourth quartiles, respectively, displayed a mean (95%confidence interval [95% CI]) change of 2.32 (-7.58-12.22), -2.70 (-13.19-7.79) and -13.04 (-23.41- -2.67) minutes in sleep duration from 2012 to 2015; p for trend=0.02. A 1-point increase in the SNI at baseline was associated with an increased risk of short nighttime sleep (Odds Ratio [OR] and 95% CI: 1.22 (1.05-1.42)), poor sleep quality (OR: 1.13; 95% CI: 1.00-1.30), and of the indicator of sleep disturbance "early awakening with difficulty getting back to sleep" (OR: 1.20; 95% CI: 1.07-1.35).

CONCLUSION

A poorer social network is associated with a higher risk of short sleep and poor sleep quality in older adults.

Later-life sleep, cognition, and neuroimaging research: an update for 2020

This review summarizes recent studies of sleep and brain health in later life, focusing on cognitive and magnetic resonance imaging (MRI)-derived outcomes. The majority of older people report sleep problems, and over one-third have sleep-disordered breathing (SDB). The research described herein builds on work demonstrating that abnormal sleep duration, sleep fragmentation, and SDB are associated with memory impairment and executive dysfunction. Self-reported short sleep is linked with greater cortical thinning and lower white matter integrity, and objectively measured fragmentation and SDB are tied to gray matter atrophy and altered connectivity. Results suggest that brain changes mediate previously identified sleep-cognition associations. Additional clinical trials are needed to determine whether treating insomnia or SDB benefits cognition in this population.