Connections between sleep and cognition in older adults

Does age affect metacognition? A cross-domain investigation using a hierarchical Bayesian framework

According to previous research, the accuracy of metacognitive judgments in aging depends on the cognitive domain involved in the task, the experimental design, and the metacognitive index used. Older adults are frequently less accurate than younger adults in judging their episodic memory, while no difference is typically observed for semantic metamemory. In addition, age-related changes in metaperception appear to be highly task-dependent. Other metacognitive domains (such as metacognition of executive functioning) have been seldom explored. This study aimed to integrate methodological and theoretical advances in the study of metacognition to answer the question of whether metacognition is impaired in healthy aging. Data were collected in a large sample (n = 443) of participants aged 18 to 79. Participants provided retrospective confidence judgments in four domains: episodic memory, semantic memory, executive functioning, and visual perception. Our measure of accuracy, metacognitive efficiency, was estimated using a hierarchical Bayesian implementation of the meta-d' model. Results showed that metacognitive efficiency decreased with age in the episodic task and increased with age in the semantic task. There was no effect of age on metacognitive efficiency in the executive and perception tasks. Moreover, metacognitive efficiency appeared to rely on a domain-general process in older adults. Explaining the episodic metamemory deficit in aging could help understand the difficulties of older adults to use inferential processes for memory search and retrieval as well as their difficulties to implement memory strategies.

Impact of different types of physical exercise on sleep quality in older population with insomnia: a systematic review and network meta-analysis of randomised controlled trials

OBJECTIVE

To measure the impact of each type of exercise on sleep quality and identify the exercise that enhances sleep quality the most.

STUDY SELECTION

Eligible randomised controlled trials that compare physical exercise to routine activities, usual care, non-physical activity, or health education to measure the Pittsburgh Sleep Quality Index.

DATA SOURCE

Studies retrieved from Medline, Embase, CINAHL, Scopus, ClinicalTrial.gov and ThaiJo from the database's inception to October 2022.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently identified studies, collected data and assessed bias. In the absence of heterogeneity, a fixed effect model was used for pairwise meta-analysis. Alternatively, a random effect model was used. A two-stage network meta-analysis used the surface under the cumulative ranking curve (SUCRA) to compare exercise efficacy.

MAIN OUTCOME

Global Pittsburgh Sleep Quality Index (GPSQI) and subdomain score.

RESULTS

This review comprised 2170 people from 25 trials. Direct meta-analysis revealed significant improvement in GPSQI with combined exercise (unstandardised mean difference (USMD) -2.35, 95% CI-3.13 to -1.57, p<0.001, I2=69.13%). GPSQI decreased considerably with aerobic activity (USMD -4.36, 95% CI -7.86 to -0.86, p=0.01, I2=97.83%). For the network meta-analysis, strengthening, aerobic and combination exercise significantly lowered GPSQI (USMD-5.75, -3.76 and -2.54, respectively). Strength training improved GPSQI scores most effectively (SUCRA 94.6%).

CONCLUSION

Exercise that strengthens muscles, rather than aerobic or combination exercises, is the most effective way to enhance sleep quality.

Loneliness partially mediates the relationship between Internet access and cognitive function in late adulthood: A cross-lagged panel analysis

OBJECTIVE

Previous studies have shown an association between Internet access and cognitive function, and have also found that loneliness is a precursor to cognitive impairment. However, little is known about the bidirectional relationship between Internet access and cognitive function, and the potential mechanisms that underlie these three variables. This study examined the reciprocal relationship between Internet access and cognitive function, as well as the mediating role of loneliness among middle-aged and older Chinese adults.

METHODS

Data were derived from four waves (2011, 2013, 2015, and 2018) of the China Health and Retirement Longitudinal Study. A total of 6578 participants aged 50 and above with complete cognitive test data at baseline were selected for the analysis. Cross-lagged panel models were applied to explore the relationship between Internet access and cognitive function, with attention to the mediating role of loneliness.

RESULTS

Reciprocal 4-wave lagged associations between Internet access and cognitive function, and the partial mediating role of loneliness were found in this study, controlling for all covariates. Increased Internet access predicts better cognitive function over time, and vice versa. Notably, this association was partially mediated by loneliness, indicating that more Internet access was associated with reduced loneliness, which was then associated with better cognitive performance.

CONCLUSIONS

This suggests that Internet access can influence individuals' cognitive function by impacting their feelings of loneliness. Multidisciplinary interventions utilizing digital connections to alleviate loneliness, enhance cognitive resilience, and delay cognitive decline may thus contribute to healthier aging in the digital era.

The subcortical correlates of self-reported sleep quality

Study objectives

To assess the association between self-reported measures of sleep quality and cortical and subcortical local morphometry.

Methods

Sleep quality, operationalized with the Pittsburgh Sleep Quality Index (PSQI), and neuroanatomical data from the full release of the young adult Human Connectome Project dataset were analyzed (N=1,112; 46% female; mean age: 28.8 years old). Local cortical and subcortical morphometry was measured with subject-specific segmentations resulting in voxelwise gray matter difference (i.e., voxel based morephometry) measurements for cortex and local shape measurements for subcortical regions. Associations between the total score of PSQI, two statistical groupings of its subcomponents (obtained with a principal component analysis), and their interaction with demographic (i.e., sex, age, handedness, years of education) and biometric (i.e., BMI) variables were assessed using a general linear model and a nonparametric permutation approach.

Results

Sleep quality-related variance was significantly associated with subcortical morphometry, particularly in the bilateral caudate, putamen, and left pallidum, where smaller shape measures correlated with worse sleep quality. Notably, these associations were independent of demographic and biometric factors. In contrast, cortical morphometry, along with additional subcortical sites, showed no direct associations with sleep quality but demonstrated interactions with demographic and biometric variables.

Conclusions

This study reveals a specific link between self-reported sleep quality and subcortical morphometry, particularly within the striatum and pallidum, reinforcing the role of these regions in sleep regulation. These findings underscore the importance of considering subcortical morphology in sleep research and highlight potential neuromodulatory targets for sleep-related interventions.

Bidirectional causal associations between frailty measures and sleep disturbances: a two-sample Mendelian randomization study

Background

Observational studies have demonstrated a strong association between sleep disturbances and frailty. However, the causality remains inconclusive. We aimed to investigate the bidirectional causal relationships between frailty measures and sleep disturbances employing a two-sample Mendelian randomization (MR) analysis.

Methods

Two-sample MR analyses were performed based on large-scale genome-wide association studies (GWAS) of the European population for frailty index (FI) (N = 175,226), Fried Frailty Score (FFS) (N = 386,565), insomnia (N = 283,595), sleep duration (N = 445,966) and sleep apnea (N = 523,366). We conducted the causal estimates using the inverse variance-weighted method (IVW), with sensitivity analyses using MR-Egger, weighted median, weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO) analysis. Cochran's Q test was performed to assess heterogeneity.

Results

We found that genetically predicted FI was associated with shorter sleep duration and sleep apnea. The genetically predicted FFS was associated with insomnia, shorter sleep duration, and sleep apnea. In the reverse direction analysis, genetic liability to insomnia, short sleep duration, and long sleep duration were associated with an increase in FI. Genetic liability to short sleep duration and long sleep duration were associated with an increase in FFS.

Conclusion

Our study provided genetic evidence supporting the bidirectional causality between frailty measures and sleep disturbances. The findings contribute to the prevention and management of frailty and sleep disturbances.

The interaction between circadian syndrome and genetic susceptibility in the risk of incident dementia: A longitudinal cohort study

BACKGROUND

Despite growing interest in circadian disturbances as potential triggers for dementia, the specific impact of circadian syndrome (CircS) on dementia incidence remains poorly understood. Moreover, the role of genetic susceptibility modulating these effects remains to be explored.

METHODS

Dementia-free participants from the UK Biobank cohort were included in the analysis. To evaluate the association between CircS and the incidence of dementia, as well as the modifying influence of genetic susceptibility on this relationship, Cox proportional hazards models were utilized.

RESULTS

During a median follow-up period of 14.55 years, 3,965 incident dementia cases were documented. CircS was found to significantly increased the risk of incident dementia, with a hazard ratio (HR) of 1.401 (95 % confidence interval [CI]: 1.296, 1.516). Compared to a CircS score of ≤3, mild CircS (HR: 1.259, 95 % CI: 1.146-1.383), moderate CircS (HR: 1.667, 95 % CI: 1.461-1.903), and severe CircS (HR: 2.028, 95 % CI: 1.397-2.944) were all significantly associated with an elevated risk of dementia. There were significant multiplicative interactions between CircS and genetic susceptibility (Pinteraction<0.001). Participants with both a high polygenic risk score (PRS) and CircS had the highest risk of incident dementia (HR: 2.551, 95 % CI: 2.169, 3.001), compared to those with a low PRS and no CircS.

CONCLUSIONS

CircS was associated with an increased risk of dementia, which might be aggravated by genetic susceptibility.

Association of reported sleep disturbances with objectively assessed mild cognitive impairment among adults in the United States

Background

Sleep is a multifaceted phenomenon influenced by both duration and quality. Various sleep disturbances have been associated with mild cognitive impairment, but the role of specific disturbances in mild cognitive impairment pathophysiology remains unclear. This study investigated the associations between distinct sleep disturbances and mild cognitive impairment in adults aged 50 and older using nationally representative data.

Methods

Longitudinal data from the Health and Retirement Study were analyzed to explore the association between mild cognitive impairment and three types of sleep disturbances: trouble falling asleep, trouble waking up, and waking up too early. Logistic regression models estimated unadjusted (Model 1) and adjusted associations accounting for sex, race/ethnicity, age, social determinants of health (Model 2), general health (Model 3), depression (Model 4), and pain and physical activity (Model 5).

Results

The study cohort included 8877 participants aged ⩾50 years in 2018 (baseline) who were followed up in 2020. Overall, 15.4% reported trouble falling asleep, 23.2% reported trouble waking up, and 12.8% reported waking up too early and being unable to fall back asleep most of the time. Among older adults, approximately 13.1% reported experiencing mild cognitive impairment; The prevalence of mild cognitive impairment was even higher in those who experienced sleep disturbances. The unadjusted odds ratio (uOR) for experiencing trouble falling asleep most of the time was 1.69 (95% CI: 1.42-2.03), for trouble waking up most of the time was 1.31 (95% CI: 1.10-1.57), and for waking up early most of the time was 1.88 (95% CI: 1.51-2.35). However, these positive associations attenuated depending on the covariate adjustment.

Conclusions

Nearly one in seven adults had mild cognitive impairment. The relationship between sleep disturbances and mild cognitive impairment has been challenging to delineate. Our findings demonstrate a positive association between sleep disturbances and mild cognitive impairment, although these associations were sensitive to covariate adjustments. These findings suggest multifaceted pathways for reducing the risk of mild cognitive impairment.

Health Behaviors and Executive Function in Late Adulthood: A Time-Varying Effect Modeling Analysis

OBJECTIVE

Cognitive decline in older adults is a public health issue, with modifiable factors like obesity and sleep potentially influencing this trajectory. Previous research on their relationship with executive function has shown mixed results, particularly across older adulthood.

METHODS

This study utilized time-varying effect modeling (TVEM) to assess the impact of body mass index (BMI) and sleep on executive function in older adults aged 60 to 79, using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 cycles (N = 2543). Executive function was evaluated using the Digit Symbol Substitution Test (DSST).

RESULTS

Findings indicated that while BMI did not significantly affect cognition, adequate sleep (7-8 hours) was linked to better executive function, especially in individuals aged 63 to 65.

CONCLUSION

These results highlight sleep's importance for cognitive health and suggest interventions focusing on sleep and weight management to mitigate age-related cognitive decline.

Cognition and objective sleep quality in post-COVID-19 patients

In the current study, we aimed (i) to evaluate sleep quality via wrist actigraphy monitoring of nonhospitalized and hospitalized post-COVID-19 condition (PCC) participants; (ii) to correlate actigraphy measures with subjective measures of sleep quality, such as the Pittsburgh Sleep Quality Index (PSQI); and (iii) to investigate whether total sleep time or sleep efficiency could affect PCC cognitive performance. We included 49 individuals with PCC from the NAUTILUS Project (NCT05307549 and NCT05307575) who were monitored for 1 week via actigraphy and who were also assessed with a comprehensive neuropsychological battery and the PSQI. We found that there were significant differences between nonhospitalized PCCs and hospitalized PCCs in the number of awakenings. We also found a correlation between the total sleep time of both measures (actigraphy and PSQI), but we did not observe correlations between objective and subjective parameters of latency and sleep efficiency. Regarding cognition and actigraphy measures, there was a trend of statistical significance in the performance of immediate visual memory, attention span and social cognition according to sleep efficiency. In conclusion, results indicate that although the PSQI provides clinically relevant indicators of sleep, there are divergent results between self-reported and objective sleep measures (actigraphy). Furthermore, we found a tendency toward statistical significance in cognitive performance in PCC participants according to their sleep efficiency which could indicate that is more important for cognitive function of post-COVID-19 patients than total sleep time.

Mechanism of action of Panax ginseng alcohol extract based on orexin-mediated autophagy in the treatment of sleep and cognition in aged sleep-deprived rats

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng (P. ginseng) C. A. Meyer. has been used extensively globally as a medicine. It has a therapeutic effect on sleep and is an attractive alternative for patients with insomnia. The United States Patent of Invention has approved the use of P. ginseng alcohol extract (GAE) in nutraceuticals or food to improve sleep. It has shown promise as an effective therapeutic agent for improving sleep and cognition. However, its mechanism of action is not yet fully understood.

AIM OF THE STUDY

To investigate the therapeutic benefits of GAE on sleep and cognition and its underlying mechanism in aged sleep-deprived rats, with a focus on orexin-mediated autophagy function.

MATERIALS AND METHODS

We conducted in vivo tests in an aged sleep-deprivation rat model produced using p-chlorophenylalanine (PCPA) coupled with modified multi-platform method to examine the therapeutic effects and mechanisms of GAE. A pentobarbital sodium-induced sleep test and water maze were used to assess sleep and cognitive performance, respectively. An enzyme-linked immunosorbent assay was used to determine orexin levels and aging and sleep markers in serum and hypothalamic tissues. Hematoxylin-eosin staining and Nissl staining were used to assess histopathological changes, and autophagy levels were assessed using transmission electron microscopy, immunofluorescence. Western blot and immunohistochemical staining were performed to detect the levels of orexin, orexin-receptor proteins, and autophagy-associated proteins to study the effects of GAE on hippocampal neurons, and the underlying mechanisms.

RESULTS

In aged sleep-deprived rats, GAE treatment prolonged sleep duration, improved cognitive function, prevented hippocampal neuronal damage, increased the number of Nissl bodies, improved aging and sleep markers, and enhanced the LC3A/B expression in autophagosomes and neurons. The amount of orexin in serum and hypothalamic tissue and OX1R, OX2R, and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) proteins also reduced, which resulted in the inhibition of the PI3K/Akt/mTOR pathway and activation of the autophagy process.

CONCLUSIONS

GAE may reduce hypothalamic orexin secretion and interact with orexin receptors to inhibit the PI3K/Akt/mTOR signalling network and activate autophagy. This may be a potential mechanism of action of GAE in regulating sleep-related cognitive function.

Sleep quality and cognitive functioning among Chinese older adults living in the US: a mixed-effects model analysis

BACKGROUND

Racial and ethnic disparities in sleep quality and cognitive health are increasingly recognized, yet little is understood about their associations among Chinese older adults living in the United States. This study aims to examine the relationships between sleep health and cognitive functioning in this population, utilizing data from the Population Study of Chinese Elderly in Chicago (PINE).

METHODS

This observational study utilized a two-wave panel design as part of the PINE, including 2,228 participants aged 65 years or older who self-identified as Chinese. Participants completed interviews at two time points. Cognitive functioning was assessed using a battery of tests, including the Chinese Mini-Mental State Examination (C_MMSE), the immediate and delayed recall of the East Boston Memory Test, the Digit Span Backwards assessment, and the Symbol Digit Modalities Test. Sleep quality was assessed using items from the Pittsburgh Sleep Quality Index (PSQI), covering four aspects: subjective sleep quality, sleep latency, sleep efficiency, and sleep duration. Insomnia was assessed using four items from the Women's Health Initiative Insomnia Rating Scale. Mixed-effects regression models were used to assess the effects of sleep parameters on baseline cognitive functioning and cognitive change over time.

RESULTS

Participants had an average age of 77.42 years (± 7.57) at baseline, with about 39% reporting fairly bad or very bad sleep quality. Poorer overall sleep quality (B = -0.01, SE = 0.01, p < .01), and more insomnia symptoms (B = -0.01, SE = 0.00, p < .001) were associated with lower baseline global cognition. However, these associations diminished over time (sleep quality: B = 0.01, SE = 0.00, p < .05; insomnia: B = 0.00, SE = 0.00, p < .05). Among sleep quality subdomains, all except sleep efficiency had significantly negative relationships with baseline global cognition. The associations between sleep parameters and the four cognitive domains were less consistent.

CONCLUSIONS

The findings highlight cross-sectional negative relationships between self-reported sleep parameters and cognition, showing distinct associations between various aspects of sleep quality and cognitive domains. Targeted interventions to improve sleep quality may have the potential to enhance cognitive health outcomes.

Can Sleep Predict Conversion to Mild Cognitive Impairment and Dementia? Results From the Hellenic Longitudinal Investigation of Aging and Diet Study

OBJECTIVE

Sleep disturbance is considered a risk factor for cognitive decline in elderly individuals. Our aim in the current study was to investigate whether baseline sleep parameters can predict the conversion from normal cognition to mild cognitive impairment or dementia at follow-up. The Hellenic Longitudinal Investigation of Aging and Diet is a longitudinal population-based study designed to estimate the prevalence and incidence of cognitive decline and dementia in the older Greek population.

METHODS

A total of 955 cognitively normal older adults (aged ≥65 y) were drawn from the Hellenic Longitudinal Investigation of Aging and Diet study. A comprehensive neurological and neuropsychological assessment was conducted at baseline and a mean of 3.1 (SD = 0.85) years later, resulting in 160 individuals diagnosed with mild cognitive impairment and 34 with dementia at follow-up, whereas 761 remained cognitively normal.

RESULTS

Using Cox regression analyses, no sleep parameters increased the risk of conversion status adjusting for demographics and clinical factors. Napping, however, decreased this risk by 19.3% (P < 0.001).

CONCLUSIONS

As several previous studies have proposed, napping constitutes a protective factor against cognitive decline. Thus, clinicians should encourage their elderly patients to adopt this healthy habit.

The impact of brain-systemic oxygenation coupling in sleep-disordered breathing on cognitive function in elderly

BACKGROUND

Intermittent hypoxia, a consequence of sleep-disordered breathing (SDB), may contribute to an increased risk of cognitive decline. However, the association between SDB and cognition remains highly variable.

METHODS

Fifty-two community-dwelling healthy older adults (28 women) were recruited. All participants underwent neuropsychiatric evaluations, simultaneous ambulatory polysomnography (PSG), and near-infrared spectroscopy (NIRS) recordings. We quantified the average coherence between oxy-Hb and SpO2 signals during SDB events to determine whether it could predict cognitive outcomes in healthy older adults, where higher coherence indicates reduced protection against systemic hypoxia.

RESULTS

The mean (SD) coherence of oxy-Hb and SpO2 was 0.16 (0.07). Linear regression analysis showed a significant association between mean coherence and worse Stroop Color Word Test scores (t=-0.304, p = .004). In contrast, oxy-Hb reduction alone and conventional SDB parameters did not show a significant association with cognition.

CONCLUSION

This is the first report to demonstrate an association between a novel parameter of brain-systemic oxygenation coherence in SDB and cognition in older adults. A higher coherence rate of cortical oxy-Hb and systemic SpO2 during SDB may reflect a loss of compensatory mechanisms against systemic hypoxia and could help stratify older adults with a higher risk for cognitive decline.

Associations of personality traits with actigraphic sleep in middle-aged and older adults

Although prior studies have examined associations of personality traits with sleep, most have investigated self-reported sleep, been cross-sectional, and focused on younger and middle-aged adults. We investigated associations of personality with actigraphic sleep parameters and changes in sleep in 398 cognitively normal adults aged 40-95 years (M ± SD = 70.1 ± 12.0) in the Baltimore Longitudinal Study of Aging. Participants completed the Revised NEO Personality Inventory (NEO-PI-R) and 6.61 days +/-1.01 nights of wrist actigraphy at the same study visit. Participants with wrist actigraphy at multiple study visits had actigraphy data at 3.11 ± 1.52 visits (follow-up = 2.35 ± 0.70 years). Adjusting for age, sex, race, education, depressive symptoms, comorbidities and interactions of these variables with time, greater extraversion was associated with higher sleep efficiency. After further adjustment for BMI, sleep medication use, and sleep apnea symptoms, greater extraversion was associated with shorter total sleep time, and greater openness was associated with shorter average wake bout length. We observed numerous interactions of personality with sex and age, with stronger personality-sleep associations generally present at younger ages (i.e., aged 50-60 vs. 70-80) and sex differences in associations. Middle-aged and older adults higher in extraversion and lower in openness may be more vulnerable to poor sleep and may benefit from screening for sleep disturbances.

Metacognitive function in young adults is impacted by physical activity, diet, and sleep patterns

Our cognitive capacities like working memory and attention are known to systematically vary over time with our physical activity levels, dietary choices, and sleep patterns. However, whether our metacognitive capacities--such as our strategic use and optimization of cognitive resources--show a similar relationship with these key lifestyle factors remains unknown. Here we addressed this question in healthy young adults by examining if physical activity, diet, and sleep patterns were predictive of self-reported metacognitive status. Participants completed a set of validated surveys assessing these lifestyle factors over the past week to month, as well as three measures of metacognition. Using multiple regression and exploratory factor analyses we identified four clusters of metacognitive processes that are sensitive to lifestyle behaviours. Specifically, knowledge of and offline regulation of cognition is linked with physical activity, on-line cognitive regulation is related to diet, and metacognitive worry is associated with sleep behaviours. These findings suggest that lifestyle behaviours do not just affect objective cognitive functioning, but also the meta-level processes we use to monitor our cognitive performance and exert strategic control over our cognitive resources.

Repetitive Transcranial Magnetic Stimulation and Tai Chi Chuan for Older Adults With Sleep Disorders and Mild Cognitive Impairment: A Randomized Clinical Trial

Importance

Sleep disorders and mild cognitive impairment (MCI) commonly coexist in older adults, increasing their risk of developing dementia. Long-term tai chi chuan has been proven to improve sleep quality in older adults. However, their adherence to extended training regimens can be challenging. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation technique that may enhance the benefits of exercise.

Objective

To investigate whether 1-Hz rTMS of the right dorsolateral prefrontal cortex could enhance the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI.

Design, Setting, and Participants

This 2-arm, sham-controlled, assessor-masked randomized clinical trial was conducted at a university hospital in China between October 2022 and February 2024. Adults aged 60 to 75 years with sleep disorders and MCI were eligible. Data analysis was performed from February to May 2024.

Intervention

Participants were randomized in a 1:1 ratio to an experimental group (tai chi chuan and 1-Hz rTMS) or a sham group (tai chi chuan and sham rTMS). Each participant received 30 sessions of personalized rTMS targeting the right dorsolateral prefrontal cortex, and the sham group underwent the same procedure. The 2 groups received 30 sessions of 60 minutes of the 24-form simplified tai chi chuan, 5 times per week for 6 weeks.

Main Outcomes and Measures

The primary outcomes were subjective sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI), in which scores range from 0 to 21, with lower scores indicating a healthier sleep quality, and global cognitive function assessed by the Montreal Cognitive Assessment (MoCA), in which scores range from 0 to 30, with higher scores indicating less cognitive impairment. The secondary outcomes included measures of objective sleep actigraphy, anxiety and depression scales, and other cognitive subdomains. Assessments were performed at baseline, 6 weeks after the intervention, and at the 12-week follow-up.

Results

A total of 110 participants (mean [SD] age, 67.9 [4.6] years; 68 female [61.8%]) were randomized to the experimental group (n = 55) and the sham group (n = 55) and included in the intention-to-treat analysis. At 6 weeks after the intervention, compared with the sham group, the experimental group showed a lower PSQI score (between-group mean difference, -3.1 [95% CI, -4.2 to -2.1]; P < .001) and a higher MoCA score (between-group mean difference, 1.4 [95% CI, 0.7-2.1]; P < .001). The per-protocol dataset analyses and 12-week follow-up showed similar results. The generalized estimated equation model revealed an interaction effect between the PSQI score (mean difference, -2.1 [95% CI, -3.1 to -0.1]; P < .001) and the MoCA total score (mean difference, 0.9 [95% CI, 0.1-1.6]; P = .01). There were 7 nonserious, unrelated adverse events (experimental group: 2; sham group: 5) with no significant difference between the 2 groups.

Conclusions and Relevance

In this randomized clinical trial, the findings suggest that 1-Hz rTMS enhanced the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI, which may be related to alterations in neural plasticity. These findings provide novel data on nonpharmacologic strategies for the rehabilitation of sleep disorders and may delay or even prevent MCI.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200063274.

Effects of mild cognitive impairment and sleep disorders on the minimum alveolar concentration value of sevoflurane

OBJECTIVES

To explore the effect of mild cognitive impairment (MCI) and MCI with sleep disorders on the potency of sevoflurane anesthesia in the elderly.

DESIGN

Prospective study methods. Dixon up-and-down methods.

SETTING

Comprehensive public tertiary hospital, Cangzhou City, Hebei Province, China.

PARTICIPANTS

70 elderly patients scheduled for elective unilateral breast cancer surgery and finally analyzed 58 patients, including 30 patients with MCI (group M) and 28 patients with MCI with sleep disorders (group MS).

OUTCOME MEASURES

The required minimum alveolar concentration (MAC) value of sevoflurane in the two groups was determined using the Dixon up-and-down method. The MAC value of sevoflurane and its 95% confidence interval (CI) were calculated using the logistic regression method. Serum melanin-concentrating hormone concentrations were determined by Elisa kits.

RESULTS

The MAC value of sevoflurane in group M was 1.43 (95% CI 1.05-1.61%), and the MAC value of sevoflurane in group MS was 1.93 (95% CI 1.78-2.08%), There were notable differences between the two groups (P < 0.0001). The level of melanin-concentrating hormone (MCH) in the MS group was significantly lower than that in the M group (21.52 ± 3.82 vs. 37.17 ± 3.66 pg/ml, P < 0.0001). There was a significant negative correlation between MCH levels and the probability of body movement during skin incision (OR = 0.844, 95% CI: 0.715-0.996, P = 0.045).

CONCLUSIONS

Patients with MCI with sleep disorders required higher doses of sevoflurane than those with MCI alone. Changes in anesthetic requirements may be related to changes in MCH levels.

The interaction between sleep patterns and oxidative balance scores on the risk of cognitive function decline: Results from the national health and nutrition examination survey 2011-2014

BACKGROUND

Unhealthy sleep and exposures to oxidative factors are both associated with poor cognitive performance (PCP), but limited evidence has been found regarding the relationship between sleep patterns and oxidative factor exposures independently or jointly with the risk of PCP.

METHODS

We analyzed data from 2249 adults aged ≥60 years in the National Health and Nutrition Examination Survey (NHANES) database (2011-2014). Self-reported questionnaires were used to collect data on sleep duration and sleep disorder, categorizing sleep duration into three groups based on responses: short (6 hours or less per night), normal (7-8 hours per night), or long (9 hours or more per night). Sleep disorder were categorized into two groups: sleep disorder, non-sleep disorder. Oxidative balance score (OBS) was calculated based on 20 oxidative stress exposures related to diet and lifestyle factors, with higher scores indicating greater antioxidant exposures. Survey-based multivariable adjusted regression analyses were conducted to examine the associations between sleep patterns or OBS alone and in combination with overall and PCP risks.

RESULTS

Compared to the normal sleep duration group, the long sleep duration group had a higher risk of PCP (DSST<34) (OR = 1.91, 95% CI = 1.05-3.48, P = 0.021); while OBS was negatively correlated with the risk of PCP (DSST<34) [Q4 vs Q1 (OR = 0.50, 95% CI = 0.29-0.92, P = 0.004)]. There was an interaction effect between sleep patterns (sleep duration, sleep disturbances) and OBS on PCP (DSST<34) (P = 0.002). Further stratified analysis showed that in individuals with normal sleep duration, long sleep duration, or no sleep disturbances, antioxidant exposures, compared to pro-oxidant exposures, reduced the risk of low cognitive function occurrence.

CONCLUSIONS

In older populations, unhealthy sleep patterns (especially excessive sleep duration) and low OBS alone or in combination increase the risk of cognitive decline. Healthy sleep and lifestyle habits rich in antioxidant factors are crucial for protecting cognitive function in older adults.

Does Sleep Moderate the Effects of Exercise Training or Complex Mental and Social Activities on Cognitive Function in Adults With Chronic Stroke? Secondary Analysis of a Randomized Trial

BACKGROUND

Exercise (EX) or cognitive and social enrichment (ENRICH) are 2 strategies for promoting cognition poststroke. Whether sleep moderates the effects of EX or ENRICH on cognition in adults with chronic stroke is unknown.

METHODS

A 3-arm parallel randomized clinical trial among community-dwelling adults aged 55+ years with chronic stroke (ie, ≥12 months since stroke). Participants were randomized to 2× per week EX, ENRICH, or balance and tone control (BAT). At baseline, device-measured sleep duration and efficiency were measured using wrist-worn actigraphy; self-reported quality was measured by Pittsburgh Sleep Quality Index (PSQI). Participants were categorized at baseline as having good or poor device-measured duration, device-measured efficiency, or self-reported quality based on PSQI. The primary cognitive outcome was Alzheimer's Disease Assessment Scale Plus (ADAS-Cog-Plus) measured at baseline, 6 months (end of intervention), and 12 months (6-month follow-up). We examined if baseline sleep categorizations (ie, good vs poor) moderated the effects of EX or ENRICH on ADAS-Cog-Plus.

RESULTS

We enrolled 120 participants in the trial (EX = 34; ENRICH = 34; BAT = 52). Sleep quality (ie, device-measured sleep efficiency or self-reported sleep quality) categorization moderated effects of EX (but not ENRICH) on ADAS-Cog-Plus. Compared with BAT participants with poor sleep quality, EX participants with poor sleep quality had better ADAS-Cog-Plus performance at 6 months (estimated mean difference for those with poor device-measured sleep efficiency: -0.48; 95% CI [-0.85, -0.10]; p = .010); estimated mean difference for those with poor self-reported sleep quality: -0.38; 95% CI [-0.70, -0.07]; p = .014). There was no effect of EX on ADAS-Cog-Plus for participants with good sleep quality. Device-measured sleep duration did not moderate intervention effects.

CONCLUSIONS

Exercise is particularly beneficial in improving cognitive function in adults with chronic stroke and poor sleep quality.

Effects of exercise on sleep quality in women - A systematic review and meta-analysis

OBJECTIVES

Insomnia affects at least one-third of the global population and is more common in women. Exercise has been reported to improve sleep quality and subsequent use of hypnotics. Therefore, we performed a meta-analysis to assess the effect of exercise on sleep quality in adult women.

DESIGN

This meta-analysis systematically assessed the effects of exercise on women's sleep quality using a random-effects model.

METHODS

We searched seven databases for randomised controlled trials examining the effect of exercise on sleep quality in women. Inclusion criteria were women aged 18 or older with insomnia symptoms, exercise used as an intervention, and the Pittsburgh Sleep Quality Index or Insomnia Severity Index as outcome measures. We excluded studies using other treatments, those involving cancer patients or pregnant women, and those with unclear, unanalysable data. A random-effects model was used for meta-analysis, with outcomes expressed as the weighted mean difference and 95 % confidence interval. Risk of bias was assessed using Cochrane Handbook criteria.

RESULTS

The meta-analysis included 16 studies. The results indicated that exercise significantly reduced the Pittsburgh Sleep Quality Index total score. Exercise implemented for <12 weeks was more effective in improving sleep quality and daytime dysfunction, whilst interventions ≥12 weeks reduced the use of sleep medication.

CONCLUSIONS

Exercise training can significantly improve sleep quality in adult women, as measured by the Pittsburgh Sleep Quality Index. Therefore, exercise can be crucial in promoting health, especially as a non-pharmacological treatment. When more studies will be available in the future, it will be possible to further explore the impact of age, type of exercise, and time of exercise.

Relationship between cognitive function and sleep quality in middle-aged and older adults for minimizing disparities and achieving equity in health: Evidence from multiple nationwide cohorts

BACKGROUND

Cognitive decline, a heavy burden on middle-aged and older adults as global aging is aggravated, was found to be associated with sleep quality. However, the country-between heterogeneity of the association prevented us from quantifying underlying relationship and identifying potential effect modifiers for vulnerable populations and targeted interventions.

METHODS

We collected data from 79,922 eligible adults in five nationwide cohorts, examined the respective relationships between cognitive function and sleep quality, synthesized underlying average relationships by meta-analysis, and explored effect modifiers by meta-regressions. Additionally, we conducted subgroup and interaction analyses to identify vulnerable populations and to determine their disparities in vulnerability.

RESULTS

Although country-between disparities exist, cognitive function is robustly associated with sleep quality in middle-aged and older adults worldwide, with an effect (β) of 0.015 [0.003, 0.027]. Executive function is the subdomain most relevant to sleep quality. Disparities in the effects of sleep quality on subdomains exist in populations with different sexes (orientation: βfemale/βmale = 1.615, P = 0.020), marital statuses (orientation: βunmarried/βmarried = 2.074, P < 0.001), education levels (orientation:βuneducated/βeducated = 2.074, P < 0.001) and chronic disease statuses (memory: βunhealthy/βhealthy = 1.560, P = 0.005).

CONCLUSIONS

Cognitive function decreases with worsening sleep quality in middle-aged and older adults. Vulnerability to poor sleep generally persists in singles, females, the uneducated and people with chronic diseases. To minimize disparities and achieve health equity, we advocate for targeted interventions, i.e., encouraging socialization in singles, confirming effectiveness of hormone replacement therapy in females, employing compulsory education in middle-aged and older adults.

Oral Chinese herbal medicine combined with donepezil for mild cognitive impairment: A systematic review and meta-analysis

BACKGROUND

This study aims to evaluate the add-on effects of oral Chinese herbal medicine (CHM) for mild cognitive impairment (MCI), when used in addition to donepezil compared to donepezil alone.

METHODS

Randomized controlled trials comparing these treatments across all types of MCI were identified from nine databases and three registers until August 2023. Outcome measures were Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and adverse events (AEs). Methodological quality was assessed using Cochrane risk-of-bias tool, and evidence certainty was evaluated using the GRADE method.

RESULTS

Involving 1611 participants across 20 studies, meta-analysis results indicate that oral CHM combined with donepezil significantly improved cognitive function in MCI patients compared to donepezil alone, as evidenced by MMSE (1.88 [1.52, 2.24], I2 = 41%, 12 studies, 993 participants) and MoCA (MD: 2.01 [1.57, 2.44], I2 = 52%, 11 studies, 854 participants). Eleven studies reported details of AEs, identifying gastrointestinal symptoms and insomnia as the most common symptoms. No significant difference in AEs frequency was found between the groups (RR: 0.91 [0.59, 1.39], I2 = 4%, 11 studies, 808 participants). All 20 studies were evaluated as having "some concerns" regarding the overall risk of bias. The certainty of evidence for MMSE was "moderate" and "low" for MoCA. From frequently utilized herbs, two classical CHM formulae were identified: Kai xin san and Si wu decoction. The observed treatment effects of commonly used herbs may be exerted through multiple pharmacological mechanisms, including anti-inflammatory, anti-oxidative stress, anti-apoptotic actions, promotion of neuronal survival and modulation of the cholinergic system.

CONCLUSIONS

The concurrent use of oral CHM and donepezil appears to be more effective than donepezil alone in improving the cognitive function of MCI, without leading to an increase in AEs. While recognizing concerns of overall methodological quality, this combined therapy should be considered as an alternative option for clinical practice.

Exploring the relationship of sleep duration on cognitive function among the elderly: a combined NHANES 2011-2014 and mendelian randomization analysis

BACKGROUND

As one of the key features of sleep, sleep duration (SD) has been confirmed to be associated with multiple health outcomes. However, the link between SD and cognitive function (CF) is still not well understood.

METHODS

We employed a combined approach utilizing data from the National Health and Nutrition Examination Survey (NHANES 2011-2014) and Mendelian Randomization (MR) methods to investigate the relationship between SD and CF. In the NHANES cross-sectional analysis, the association between these variables was primarily examined through multivariate linear regression to explore direct correlations and utilized smoothing curve fitting to assess potential nonlinear relationships. To ensure the robustness of our findings, subgroup analyses were also conducted. MR analysis was used to assess the causal relationship between SD and sleeplessness on CF. After excluding confounding factors, univariate and multivariate MR were performed using inverse variance weighting (IVW) as the main analysis method, and sensitivity analysis was performed.

RESULTS

The results of our cross-sectional study indicate a notable negative association between SD and CF, forming an inverted U-shaped curve with the inflection point occurring at SD = 6 h. This relationship remains consistent and robust across subgroup analyses differentiated by variables such as age, levels of physical activity, and frequency of alcohol intake. In MR analysis, IVW analysis showed no causal relationship between SD and sleeplessness on CF (Both P > 0.05).

CONCLUSION

Cross-sectional studies suggest the existence of an inverted U-shaped correlation between SD and CF among the elderly. However, MR analysis did not reveal a causal relationship between SD and CF, which the lack of nonlinear MR analysis may limit. These findings provide evidence from a sleep perspective for optimizing cognitive strategies in older adults.

Sleep macro-architecture and dementia risk in adults: Meta-analysis of 5 cohorts from the Sleep and Dementia Consortium

Study objectives

Poor sleep may play a role in the risk of dementia. However, few studies have investigated the association between polysomnography (PSG)-derived sleep architecture and dementia incidence. We examined the relationship between sleep macro-architecture and dementia incidence across five US-based cohort studies from the Sleep and Dementia Consortium (SDC).

Methods

Percent of time spent in stages of sleep (N1, N2, N3, REM sleep), wake after sleep onset and sleep maintenance efficiency were derived from a single night home-based PSG. Dementia was ascertained in each cohort using its cohort-specific criteria. Each cohort performed Cox proportional hazard regressions for each sleep exposure and incident dementia, adjusting for age, sex, body mass index, anti-depressant use, sedative use, and APOE e4 status. Results were then pooled in random effects meta-analyses.

Results

The pooled sample comprised 4,657 participants (30% women) aged ≥60 years (mean age was 74 years at sleep assessment). There were 998 (21.4%) dementia cases (median follow-up time of 5 to 19 years). Pooled effects of the five cohorts showed no association between sleep architecture and incident dementia. When meta-analyses were restricted to the three cohorts which had dementia case ascertainment based on DSM-IV/V criteria (n=2,374), higher N3% was marginally associated with an increased risk of dementia (HR: 1.06; 95%CI: 1.00-1.12, per percent increase N3, p=0.050).

Conclusions

There were no consistent associations between sleep macro-architecture measured and the risk of incident dementia. Implementing more nuanced sleep metrics remains an important next step for uncovering more about sleep-dementia associations.

Association between sleep quality and cognitive impairment in older adults hypertensive patients in China: a case-control study

Background

Previous studies have found that poor sleep quality promotes the occurrence of cognitive impairment (CI), but this relationship has been rarely reported in older adults hypertensive patients. The purpose of this study was to investigate the relationship between sleep quality and CI in older adults hypertensive patients and the mediating effect of sleep quality between physical activity (PA) and CI.

Methods

A total of 2072 older adults hypertensive patients were included in this case-control study. Five hundred and eighteen older adults hypertensive patients with CI were matched 1:3 by age and sex to 1,554 older adults hypertensive patients with normal cognitive function. The International Physical Activity Questionnaire-Long Form, Pittsburgh Sleep Quality Index, and Mini-Mental State Examination were used to evaluate PA intensity, sleep quality, and cognitive function in older adults hypertensive patients. Multivariate logistic regression and the mediation package in R Language were used to analyze the relationship between sleep quality and CI and the mediating effect of sleep quality between PA intensity and CI in older adults hypertensive patients.

Results

After adjusting for all confounding factors, sleep quality was positively correlated with CI in older adults hypertensive patients (OR = 2.565, 95%CI: 1.958-3.360, p < 0.001), and this relationship also existed in the older adults hypertensive patients with education levels of primary school and below and junior high school and above (OR = 2.468, 95%CI: 1.754-3.473, p < 0.001; OR = 2.385, 95%CI: 1.367-4.161, p = 0.002). In addition, sleep quality mediated part of the mediating effect between PA intensity and CI in older adults hypertensive patients (Za*Zb: - 17.19339; 95%CI: -0.37312, -0.04194).

Conclusion

Poor sleep quality was associated with the occurrence of CI in older adults hypertensive patients, and this relationship also existed in older adults hypertensive patients with education levels of primary school and below and junior high school and above.

Self-reported physical activity and sleep quality is associated with working memory function in middle-aged and older adults during the COVID-19 pandemic

While previous work has shown a positive relationship between cognitive performance and lifestyle factors in younger adults, evidence for this relationship among middle-aged and older adults has been mixed. The current study aimed to further test the relationship among physical activity, sleep quality, and memory performance in middle-aged and older adults, and to test whether this relationship holds up during the COVID-19 pandemic. Our results showed that physical activity was associated with better sleep quality and better working memory performance, and better sleep quality was associated with better working memory and self-perceptions of everyday memory abilities. Additionally, we found that the effects of physical activity on working memory were partially mediated by sleep quality. While these effects were small and only correlational in nature, they lend further support to the notion that sleep quality and physical activity are beneficial to memory later in life, even during a global pandemic.

Improving Memory Through Better Sleep in Community-Dwelling Older Adults: A Tai Chi Intervention Study

OBJECTIVES

The relationship between sleep and memory has been well documented. However, it remains unclear whether a mind-body exercise, that is, Tai Chi exercise, can improve memory performance in older adults by improving their subjective and objective sleep.

METHODS

A randomized controlled trial was conducted with participants (M = 67.36, 56-79 years) randomly assigned to Tai Chi and control groups. The primary outcomes were sleep, both subjectively reported and objectively assessed by actigraphy, and memory performance, as well as the mediating role of sleep in memory improvement with Tai Chi practice.

RESULTS

Tai Chi exercise led to improvements in subjective sleep, as indicated by Insomnia Severity Index (ISI) (p < .001, Cohen's d = 0.62) and daytime dysfunction of the Pittsburgh sleep quality index (PSQI) (p = .02, Cohen's d = 0.80), and in actigraphy-assessed sleep onset latency (p < .01, Cohen's d = 0.61), as well as improved memory performance on digit span forward (p < .001, Cohen's d = 1.20) and visual spatial memory tasks (p < .01, Cohen's d = 0.83) compared to the control group. Importantly, Tai Chi practice improved digit span forward memory performance through parallel mediation of both subjective sleep (i.e., daytime dysfunction of the PSQI) and objective sleep (i.e., sleep onset latency; b = 0.29, p < .01).

DISCUSSION

Our findings uncovered the potential benefits of Tai Chi exercise in relation to both subjective and objective sleep in older adults, in turn, how sleep changes played a role in the link between Tai Chi exercise and memory changes in older adults.

Exerkine irisin mitigates cognitive impairment by suppressing gut-brain axis-mediated inflammation

INTRODUCTION

Exercise has been recognized to improve cognitive performance by optimizing gut flora and up-regulating exerkine irisin.

OBJECTIVE

Although exercise-induced irisin is beneficial to cognitive improvement, whether this benefit is achieved by optimizing gut microbiota and metabolites is not fully explored.

METHODS

After aerobic exercise and exogenous irisin interventions for 12 weeks, the 16S rRNA and metabolites in feces of 21-month-old mice were analyzed. Meanwhile, the differential miRNAs and mRNAs in hippocampal tissues were screened by high-throughput sequencing. Relevant mRNAs and proteins were evaluated by RT-PCR, Western blot, and immunofluorescence.

RESULTS

Compared with the young control mice, irisin levels and cognitive capacity of aged mice revealed a significant reduction, while aerobic exercise and intraperitoneal injection of exogenous irisin reversed aging-induced cognitive impairment. Similarly, 147 up-regulated and 173 down-regulated metabolites were detected in aged mice, while 64 and 45 up-regulated and 225 and 187 down-regulated metabolites were detected in aged mice with exercise and irisin interventions, respectively. Moreover, during hippocampal miRNA and mRNA sequencing analysis, 9 differential gut flora and 35 differential genes were identified to be correlated with the inflammatory signaling mediated by the TLR4/MyD88 signal pathway.

CONCLUSION

Aging-induced cognitive impairment is due to insulin resistance induced by TLR4/MyD88 signaling activation in hippocampal tissues mediated by gut microbiota and metabolite changes. Myokine irisin may be an important mediator in optimizing gut microbiota and metabolism for an improved understanding of mitigated aging process upon exercise interventions.

Lifestyle factors associated with episodic memory in middle-aged and older adults: evidence from a 9-year longitudinal study

BACKGROUND

Episodic memory naturally deteriorates with age, and its deficits are widely recognized as the most significant feature and the most sensitive indicator of cognitive decline. It has been suggested that adopting a healthy lifestyle can play a protective role in preserving episodic memory. This study aimed to systematically examine the relationship between lifestyle factors (social activities, leisure activities, physical activities, internet use, smoking, alcohol drinking, and sleep quality) and episodic memory in middle-aged and older adults.

METHODS

The current study included 10,392 participants from the Chinese Health and Retirement Longitudinal Survey. A linear mixed model was used to explore the associations between lifestyle factors and episodic memory performance and the age- and sex-specific effects of the association.

RESULTS

Low-frequency alcohol drinking, higher engagement in social, leisure, and physical activities, increased internet use, and improved sleep quality were associated with better episodic memory performance in middle-aged and older adults. Stratified analyses demonstrated that internet use significantly correlated with episodic memory performance in middle-aged adults but not in older adults. On the other hand, sleep quality showed a significant association with episodic memory performance in women but not in men.

CONCLUSIONS

This study highlights the association between various lifestyle factors and episodic memory performance, with variations observed based on age and sex. Adopting healthy lifestyle factors can have positive effects on episodic memory in middle-aged adults, emphasizing the importance of adhering to healthy lifestyles from middle age onwards to counteract episodic memory decline.

Implementing AI-Driven Bed Sensors: Perspectives from Interdisciplinary Teams in Geriatric Care

Sleep is a crucial aspect of geriatric assessment for hospitalized older adults, and implementing AI-driven technology for sleep monitoring can significantly enhance the rehabilitation process. Sleepsense, an AI-driven sleep-tracking device, provides real-time data and insights, enabling healthcare professionals to tailor interventions and improve sleep quality. This study explores the perspectives of an interdisciplinary hospital team on implementing Sleepsense in geriatric hospital care. Using the interpretive description approach, we conducted focus groups with physicians, nurses, care aides, and an activity worker. The Consolidated Framework for Implementation Research (CFIR) informed our thematic analysis to identify barriers and facilitators to implementation. Among 27 healthcare staff, predominantly female (88.89%) and Asian (74.1%) and mostly aged 30-50 years, themes emerged that Sleepsense is perceived as a timesaving and data-driven tool that enhances patient monitoring and assessment. However, barriers such as resistance to change and concerns about trusting the device for patient comfort and safety were noted, while facilitators included training and staff engagement. The CFIR framework proved useful for analyzing implementation barriers and facilitators, suggesting future research should prioritize effective strategies for interdisciplinary team support to enhance innovation adoption and patient outcomes in rehabilitation settings.

Sleep disturbances and psychomotor retardation in the prediction of cognitive impairments in patients with major depressive disorder

BACKGROUND

Symptoms of depression and comorbid anxiety are known risk factors for cognitive impairment in major depressive disorder (MDD). Understanding their relationships is crucial for developing targeted interventions to mitigate cognitive impairments in MDD patients. We expect that the severity of sleep disturbances and other depressive symptoms will be positively correlated with the degree of cognitive impairments. We also hypothesize that anxiety symptoms, especially psychic anxiety, is a key factor in predicting cognitive performance in MDD patients and may indirectly contribute to cognitive impairment by affecting sleep disturbances and other potential factors.

AIM

To determine which dimension of the depressive and anxiety symptoms predicts cognitive impairment during a depressive episode.

METHODS

A comprehensive neurocognitive test battery assessed executive function, attention, processing speed, and memory in 162 medication-free MDD patients and 142 matched healthy controls. The 24-item Hamilton Depression Rating Scale was used to assess depressive symptoms, and the 14-item Hamilton Anxiety Scale was used to assess anxiety symptoms. Linear regression analyses and mediation analyses were conducted to evaluate the impact of depressive and anxiety symptoms, as well as their interactions, on cognitive impairments.

RESULTS

Among the depressive symptoms, sleep disturbances were associated with poorer executive function (P = 0.004), lower processing speed (P = 0.047), and memory impairments (P < 0.001), and psychomotor retardation (PR) was associated with lower processing speed in patients with MDD (P = 0.019). Notably, PR was found to mediate the impact of sleep disturbances on the processing speed. Regarding anxiety symptoms, psychic anxiety, rather than somatic anxiety, was associated with cognitive impairments in all aspects. Sleep disturbances mediated the effect of psychic anxiety on executive function [β = -0.013, BC CI (-0.027, -0.001)] and memory [β = -0.149, BC CI (-0.237, -0.063)], while PR mediated its effect on processing speed (β = -0.023, BC CI (-0.045, -0.004)].

CONCLUSION

Sleep disturbances may be a key predictor of poorer executive function, lower processing speed, and memory loss, while PR is crucial for lower processing speed during a depressive episode. Psychic anxiety contributes to all aspects of cognitive impairments, mediated by sleep disturbances and PR.

Sleep Disorders and Dementia Risk in Older Patients with Kidney Failure: A Retrospective Cohort Study

Key Points

Older patients with kidney failure who are newly diagnosed with sleep disorders are at higher risk of developing any type of dementia, vascular dementia, and other/mixed types of dementia. For older patients with kidney failure who are diagnosed with obstructive sleep apnea, positive airway pressure therapy is an intervention that is associated with lower dementia risk.

Background

Community-dwelling older adults with sleep disorders are at higher risk of developing dementia. Greater than 50% of older patients with kidney failure experience sleep disorders, which may explain their high burden of dementia.

Methods

Among 216,158 patients (aged 66 years and older) with kidney failure (United States Renal Data System; 2008–2019), we estimated the risk of dementia (including subtypes) associated with sleep disorders using Cox proportional hazards models with propensity score weighting. We tested whether positive airway pressure (PAP) therapy was associated with reduced dementia risk among patients with obstructive sleep apnea (OSA).

Results

26.3% of patients were diagnosed with sleep disorders; these patients had a higher 5-year unadjusted cumulative incidence for any type of dementia (36.2% versus 32.3%; P < 0.001), vascular dementia (4.4% versus 3.7%; P < 0.001), and other/mixed dementia (29.3% versus 25.8%; P < 0.001). Higher risk of any type of dementia was identified in patients with insomnia (adjusted hazard ratio [aHR], 1.42; 95% confidence interval [CI], 1.34 to 1.51), sleep-related breathing disorders (SRBDs) (aHR, 1.20, 95% CI, 1.17 to 1.23), and other sleep disorders (aHR, 1.24; 95% CI, 1.11 to 1.39). Higher vascular dementia risk was observed in patients with insomnia (aHR, 1.43; 95% CI, 1.19 to 1.73) and SRBDs (aHR, 1.15; 95% CI, 1.07 to 1.24). Patients with SRBDs (aHR, 1.07; 95% CI, 1.00 to 1.15) were at higher risk of Alzheimer disease. Among patients with OSA, PAP therapy was associated with lower risk of any type of dementia (aHR, 0.82; 95% CI, 0.76 to 0.90) and vascular dementia (aHR, 0.65; 95% CI, 0.50 to 0.85).

Conclusions

Older patients with kidney failure and sleep disorders are at a higher risk of dementia. Sleep is an important modifiable factor that should be considered for targeted interventions to mitigate dementia risk in patients with kidney failure. For patients with OSA, PAP therapy is associated with lower dementia risk.

Sleep and nighttime behavior disorders in older adults: associations with hypercholesterolemia and hypertriglyceridemia at baseline, and a predictive analysis of incident cases at 12 months follow-up

INTRODUCTION

Sleep disorders, particularly insomnia and obstructive sleep apnea, are associated with dyslipidemia in the general population. The study's aim was to explore the association between pathological Cholesterol and Triglyceride levels, and sleep and nighttime behavior disorders (SNBD) in older adults, whether they might predict SNBD onset, and to emphasize the role of body mass index (BMI) in this association.

METHODS

Alzheimer's Disease Neuroimaging Initiative (ADNI) population with complete Cholesterol, Triglyceride, SNBD, and neurocognitive data were included. Logistic regression was performed to study the association between hypercholesterolemia, hypertriglyceridemia, and SNBD at baseline and at 12 months. Relevant confounders, particularly BMI, were adjusted for.

RESULTS

Among the 2,216 included cases, 1,045 (47%) were females, and the median age was 73 years (IQR: 68, 78). At baseline, 357 (16%) had SNBD and 327 (18%) at 12 months; 187 of them were incident cases. There were more cases of baseline SNBD in the hypertriglyceridemia group than in those without (19% vs. 14%, P-value = 0.003). Similarly, more follow-up SNBD cases had hypertriglyceridemia at baseline (21% vs. 16%, P-value = 0.025). SNBD cases at baseline had significantly higher serum Triglyceride levels than those without (132 vs. 118mg/dL, P-value < 0.001). Only hypertriglyceridemia was significantly associated with baseline SNBD (crude OR = 1.43, 95%CI: 1.13,1.80, P-value = 0.003), even after adjustment for confounding factors (adj. OR = 1.36, 95%CI: 1.06,1.74, P-value = 0.016) and (BMI-adj. OR = 1.29, 95%CI: 1.00,1.66, P-value = 0.048). None of the dyslipidemia forms did predict incident cases at 12 months.

CONCLUSIONS

Hypertriglyceridemia, but not hypercholesterolemia, was associated with higher odds of SNBD. The association was independent of BMI. None of the dyslipidemia forms did predict incident SNBD over 12 months. Sleep disorders should motivate a systematic screening of dyslipidemia in older adults and vice versa.

The Relationship between Sleep Quality and Posture: A Study on University Students

The aim of this study is to investigate body posture, physical exercises, head-neck relationship, and sleep quality among university students. A total of 96 students, with an average age of 20.86 ± 1.24 years and an average BMI of 23.41 ± 2.56, voluntarily participated in the study. The REEDCO Posture Evaluation (RPE) was used to assess the participants' body posture scores. Head and neck measurements were taken using the Apecs-AI Posture Evaluation and Correction System® (Apecs Posture Analysis Pro Plus Version 8.2.6). Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Pearson correlation analysis indicated that increased caffeine consumption was associated with poorer sleep quality (r = 0.267, p < 0.05). Additionally, increased participation in physical activities was associated with improved sleep quality, with those engaging in sports having better sleep quality scores (r = -0.278, p < 0.05). As physical activity increased, REEDCO scores decreased (r = -0.423, p < 0.05), while scores for right head (r = 0.210, p < 0.05) and left head (r = 0.247, p < 0.05) increased. Significant negative correlations were found between REEDCO scores and right head (r = -0.296, p < 0.05) and left head (r = -0.463, p < 0.05) scores. In conclusion, due to the limited number of studies investigating head-neck relationships and sleep quality, definitive conclusions cannot be drawn; further and more comprehensive research is needed.

Definition, assessment and treatment of cognitive impairment associated with schizophrenia: expert opinion and practical recommendations

A considerable proportion of patients with schizophrenia perform below population norms on standardized neuropsychological tests, and the performance of those performing within normal range is lower than predicted based on parental education. Cognitive impairment predates the onset of psychosis, is observed during symptom remission and in non-affected first-degree relatives of patients. At the present time, cognitive deficits are regarded as key features of schizophrenia, important determinants of poor psychosocial outcome and targets for both pharmacological and non-pharmacological treatment strategies. A group of eight key opinion leaders reviewed and discussed latest advances in scientific research and current good clinical practices on assessment, management, and treatment of CIAS. In the present paper they summarize the current evidence, identify main gaps between current knowledge and mental health services clinical practice, and provide practical recommendations to reduce the gap.

Causal Associations of Sleep Apnea With Alzheimer Disease and Cardiovascular Disease: A Bidirectional Mendelian Randomization Analysis

BACKGROUND

Sleep apnea (SA) has been linked to an increased risk of dementia in numerous observational studies; whether this is driven by neurodegenerative, vascular, or other mechanisms is not clear. We sought to examine the bidirectional causal relationships between SA, Alzheimer disease (AD), coronary artery disease (CAD), and ischemic stroke using Mendelian randomization.

METHODS AND RESULTS

Using summary statistics from 4 recent, large genome-wide association studies of SA (n=523 366), AD (n=94 437), CAD (n=1 165 690), and stroke (n=1 308 460), we conducted bidirectional 2-sample Mendelian randomization analyses. Our primary analytic method was fixed-effects inverse variance-weighted (IVW) Mendelian randomization; diagnostics tests and sensitivity analyses were conducted to verify the robustness of the results. We identified a significant causal effect of SA on the risk of CAD (odds ratio [ORIVW]=1.35 per log-odds increase in SA liability [95% CI=1.25-1.47]) and stroke (ORIVW=1.13 [95% CI=1.01-1.25]). These associations were somewhat attenuated after excluding single-nucleotide polymorphisms associated with body mass index (ORIVW=1.26 [95% CI=1.15-1.39] for CAD risk; ORIVW=1.08 [95% CI=0.96-1.22] for stroke risk). SA was not causally associated with a higher risk of AD (ORIVW=1.14 [95% CI=0.91-1.43]). We did not find causal effects of AD, CAD, or stroke on risk of SA.

CONCLUSIONS

These results suggest that SA increased the risk of CAD, and the identified causal association with stroke risk may be confounded by body mass index. Moreover, no causal effect of SA on AD risk was found. Future studies are warranted to investigate cardiovascular pathways between sleep disorders, including SA, and dementia.

Cognitive impairment and depression precede increased HDL-C levels in middle-aged and older Chinese adults: cross-lagged panel analyses

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) is widely recognized for its protective effects against cognitive decline. However, recent studies have presented conflicting results, with some suggesting no significant cognitive benefits or even an increased risk of dementia associated with high HDL-C levels. For those who suffer from depression, the cognitive benefits of HDL-C may be diminished or reversed. The purpose of this study is to investigate the associations between HDL-C, cognitive ability, and depressive symptoms in middle-aged and older Chinese adults.

METHODS

The datasets utilized were sourced from the China Health and Retirement Longitudinal Study (CHARLS) for the years 2011 and 2015, comprising 4,302 participants. Cross-lagged models were employed to explore the temporal sequence between cognitive performance and HDL-C levels, and to examine the interplay among depression, cognition, and HDL-C. Confounding factors such as sociodemographic characteristics, sleep conditions, and history of chronic diseases were controlled for.

RESULTS

The analysis revealed unidirectional effects of baseline impaired cognition and greater severity of depression on increased HDL-C levels at follow-up (β =  - 0.036 and β = 0.028, respectively, P < 0.05). However, higher baseline HDL-C levels did not significantly predict cognitive performance or depression 4 years later (β =  - 0.008 and β = 0.023, respectively, P > 0.05). Depressive symptoms and cognition were found to have a significant bidirectional association (β =  - 0.026 and β =  - 0.053, respectively, P < 0.05).

CONCLUSIONS

Cognitive impairment and depression are associated with higher HDL-C levels, whereas higher HDL-C levels do not appear to protect against cognitive decline or depressive symptoms. These findings underscore the importance of preserving cognitive and mental health, which may lower the likelihood of cardiovascular disease and dementia. Future studies should validate these findings and develop targeted interventions tailored to specific populations.

Use of mHealth Technologies to Increase Sleep Quality among Older Adults: A Scoping Review

Sleep disorders increase with age and are known risk factors for several mental and physical diseases. They also significantly contribute to a lower quality of life. Nonpharmaceutical approaches, such as cognitive behavioral therapy for insomnia, sleep hygiene advice, relaxation exercises, and physical activity programs, can be delivered directly to patients via mHealth technologies, thereby increasing the accessibility of such interventions and reducing health care-related costs. This scoping review aims to evaluate the effectiveness of mHealth interventions for improving sleep quality among older adults. Published studies in the last 10 years (2013-2023) were identified by searching electronic medical databases (PubMed, PsycINFO, CINAHL, and Scopus) in July 2023 and were independently reviewed by two different authors. The analysis of the data was performed in 2023. The research retrieved 693 records; after duplicates were removed, 524 articles were screened based on their title and abstract, and 28 of them were assessed in full text. A total of 23 studies were excluded because they did not meet the inclusion criteria in terms of population age (60 years or over) or type of intervention (mHealth-based) or because they addressed secondary insomnia. A total of five studies were included in this review, and all of them reported improvements in subjective sleep quality after the application of the mHealth interventions. Two studies also conducted objective assessments of sleep outcomes using actigraphy, reporting improvements only in some of the variables considered. Despite the limited number of available studies, these results are promising and encourage further research.

Association between nighttime sleep duration, nap time, and mild cognitive impairment in Chinese older adults: a cross-sectional study

OBJECTIVE

This study aims to investigate the relationship between midday nap time, nighttime sleep duration, and mild cognitive impairment (MCI) in Chinese older adults and determine the recommended sleep duration to provide a scientific basis for preventing and managing MCI in this population.

METHODS

Utilizing the 2020 China Health and Retirement Longitudinal Study database, the demographic data, health status, and lifestyle information of the study participants were collected. A total of 5,314 valid samples were included in the analysis. Logistic regression and restricted cubic spline plots were employed to explore the relationship between sleep patterns and MCI.

RESULTS

In the cross-sectional analysis, a linear relationship was observed between midday nap duration and MCI among Chinese elderly. The probability of MCI was lowest among those who napped for less than 30 min at noon. Compared with individuals who napped for30-90 min, those who did not nap were more likely to have MCI (OR = 1.30, 95% CI: 1.05-1.60). Older adults with napping duration < 30 min (OR = 0.73, 95% CI:0.56-0.95) also exhibited lower probability of MCI when compared those without napping habit, Nighttime sleep duration exhibited a U-shaped relationship with MCI. Individuals with less than approximately 6 h of nighttime sleep showed a gradual decrease in the probability of MCI with increasing sleep duration, whereas those with more than 7.5 h demonstrated an increase in the probability of MCI with longer sleep duration. Older adults who slept less than 6 h at night (OR = 1.22, 95% CI: 1.01 ~ 1.46) or more than 8 h (OR = 1.78, 95% CI: 1.35-2.33) were more likely to develop MCI compared with those who slept 6 to 8 h.

CONCLUSION

After controlling for potential confounding variables, both nighttime sleep duration and midday nap duration exhibited a nonlinear "U"-shaped relationship with MCI among the elderly. The probability of depression was lower with a nap duration of approximately 60 min, and the optimal nighttime sleep duration was 6-8 h, with around 7 h providing the greatest cognitive benefits.

Prolonged sleep duration as a predictor of cognitive decline: A meta-analysis encompassing 49 cohort studies

Despite numerous studies have explored the association between sleep duration and cognition, the link between sleep duration trajectories and cognition remains underexplored. This systematic review aims to elucidate this correlation. We analyzed 55 studies from 14 countries, comprising 36 studies focusing on sleep duration, 20 on insomnia, and 13 on hypersomnia. A total of 10,767,085 participants were included in 49 cohort studies with a mean follow-up duration of 9.1 years. A non-linear association between sleep duration and cognitive decline was identified. Both long (risk ratio (RR):1.35, 95 % confidence intervals (CIs):1.23-1.48) and short sleep durations (RR: 1.12, 95 % CIs:1.03-1.22) were associated with an elevated risk of cognitive decline compared to moderate sleep duration. Additionally, hypersomnia (RR:1.26, 95 % CIs: 1.15-1.39) and insomnia (RR: 1.16, 95 % CIs: 1.002-1.34) were also linked to an increased risk. Moreover, prolonged sleep duration posed a higher risk of cognitive decline than stable sleep duration (RR:1.42, 95 % CIs:1.27-1.59). Importantly, transitioning from short or moderate to long sleep duration, as well as persistent long sleep duration, exhibited higher RRs for cognitive decline (RRs: 1.94, 1.40, and 1.28, respectively) compared to persistent moderate sleep duration. Our findings underscore the significance of prolonged sleep duration, alongside short and long sleep durations, with an elevated risk of cognitive decline. The association is tied to the degree of sleep duration changes. Our study highlights the importance of considering changes in sleep patterns over time, not just static sleep durations.

Prevalence of sleep disturbances in people with mild cognitive impairment: A systematic review and meta-analysis

This review was performed to determine sleep disturbance prevalence in individuals with mild cognitive impairment (MCI). The MEDLINE, Embase, Cochrane Library, CINAHL, PsycINFO, and Web of Science databases were systematically searched from inception to January 20, 2024. Fifty-two studies fulfilling the eligibility criteria were included. However, six of these studies were excluded from data synthesis due to poor methodological quality. The subjective sleep disturbance prevalence among all individuals with MCI was 35.8 % (95 % CI: 31.9-39.7) across 44 studies, and the objective sleep disturbance prevalence was 46.3 % (95 % CI: 36.3-56.3) across 6 studies. Five studies examined TST and WASO, while three assessed SE. Among all potential objective assessments of sleep disturbance prevalence, only TST, WASO, and SE could be meta-analyzed in MCI because of the limited number of studies available. The estimated sleep disturbance prevalence differed significantly according to measurement method, geographical region, and research design. However, the data source did not significantly influence prevalence estimates. In meta-regression analysis, publication year, participant age, percentage of females, and study quality did not predict prevalence. As subjective and objective sleep disturbances are common in people with MCI, effective intervention strategies should be developed to alleviate them.

Amyloid profile is associated with sleep quality in preclinical but not in prodromal Alzheimer's disease older adults

BACKGROUND

Few studies have assessed whether neuropathological markers of AD in the preclinical and prodromal stages are associated with polysomnographic changes and obstructive sleep apnea (OSA).

METHODS

This was a cross-sectional, case-control study of older adults (≥60 years) without relevant clinical and psychiatric comorbidities selected randomly from a cohort of individuals without dementia in a tertiary university hospital in São Paulo, Brazil. They underwent neuropsychological evaluation for clinical diagnosis and were allocated into two samples: cognitively unimpaired (CU) and mild cognitive impairment (MCI). Also, they underwent PET-PiB to determine the amyloid profile and all-night in-lab polysomnography. For each sample, we compared polysomnographic parameters according to the amyloid profile (A+ vs A-).

RESULTS

We allocated 67 participants (mean age 73 years, SD 10,1), 70 % females, 14 ± 5 years of education, into two samples: CU (n = 28, 42.4 %) and MCI (n = 39, 57.6 %). In the CU sample, the group A+ (n = 9) showed worse sleep parameters than A- (n = 19) (lower total sleep time (p = 0.007), and sleep efficiency (p = 0.005); higher sleep onset latency (p = 0.025), wake time after sleep onset (p = 0.011), and arousal index (AI) (p = 0.007)), and changes in sleep structure: higher %N1 (p = 0.005), and lower %REM (p = 0.006). In the MCI sample, MCI A-had higher AI (p = 0.013), respiratory disturbance index (p = 0.025, controlled for age), and higher rates of severe OSA than A+.

DISCUSSION

The amyloid profile was associated with polysomnographic markers of worse sleep quality in individuals with preclinical AD but not with prodromal AD, probably due to the higher frequencies of severe OSA.

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.

Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months

OBJECTIVE

Lifestyle habits after middle age significantly impact the maintenance of cognitive function in older adults. Nutritional intake is closely related to lifestyle habits; therefore, nutrition is a pivotal factor in the prevention of dementia in the preclinical stages. Matcha green tea powder (matcha), which contains epigallocatechin gallate, theanine, and caffeine, has beneficial effects on cognitive function and mood. We conducted a randomized, double-blind, placebo-controlled clinical study over 12 months to examine the effect of matcha on cognitive function and sleep quality.

METHODS

Ninety-nine participants, including 64 with subjective cognitive decline and 35 with mild cognitive impairment were randomized, with 49 receiving 2 g of matcha and 50 receiving a placebo daily. Participants were stratified based on two factors: age at baseline and APOE genotype. Changes in cognitive function and sleep quality were analyzed using a mixed-effects model.

RESULTS

Matcha consumption led to significant improvements in social acuity score (difference; -1.39, 95% confidence interval; -2.78, 0.002) (P = 0.028) as evaluated by the perception of facial emotions in cognitive function. The primary outcomes, that is, Montreal Cognitive Assessment and Alzheimer's Disease Cooperative Study Activity of Daily Living scores, showed no significant changes with matcha intervention. Meanwhile, Pittsburgh Sleep Quality Index scores indicated a trend toward improvement with a difference of 0.86 (95% confidence interval; -0.002, 1.71) (P = 0.088) between the groups in changes from baseline to 12 months.

CONCLUSIONS

The present study suggests regular consumption of matcha could improve emotional perception and sleep quality in older adults with mild cognitive decline. Given the widespread availability and cultural acceptance of matcha green tea, incorporating it into the daily routine may offer a simple yet effective strategy for cognitive enhancement and dementia prevention.

Multidimensional Sleep Profiles via Machine learning and Risk of Dementia and Cardiovascular Disease

Importance

Sleep health comprises several dimensions such as duration and fragmentation of sleep, circadian activity, and daytime behavior. Yet, most research has focused on individual sleep characteristics. Studies are needed to identify sleep profiles incorporating multiple dimensions and to assess how different profiles may be linked to adverse health outcomes.

Objective

To identify actigraphy-based 24-hour sleep/circadian profiles in older men and to investigate whether these profiles are associated with the incidence of dementia and cardiovascular disease (CVD) events over 12 years.

Design

Data came from a prospective sleep study with participants recruited between 20032005 and followed until 2015-2016.

Setting

Multicenter population-based cohort study.

Participants

Among the 3,135 men enrolled, we excluded 331 men with missing or invalid actigraphy data and 137 with significant cognitive impairment at baseline, leading to a sample of 2,667 participants.

Exposures

Leveraging 20 actigraphy-derived sleep and circadian activity rhythm variables, we determined sleep/circadian profiles using an unsupervised machine learning technique based on multiple coalesced generalized hyperbolic mixture modeling.

Main Outcomes and Measures

Incidence of dementia and CVD events.

Results

We identified three distinct sleep/circadian profiles: active healthy sleepers (AHS; n=1,707 (64.0%); characterized by normal sleep duration, higher sleep quality, stronger circadian rhythmicity, and higher activity during wake periods), fragmented poor sleepers (FPS; n=376 (14.1%); lower sleep quality, higher sleep fragmentation, shorter sleep duration, and weaker circadian rhythmicity), and long and frequent nappers (LFN; n=584 (21.9%); longer and more frequent naps, higher sleep quality, normal sleep duration, and more fragmented circadian rhythmicity). Over the 12-year follow-up, compared to AHS, FPS had increased risks of dementia and CVD events (Hazard Ratio (HR)=1.35, 95% confidence interval (CI)=1.02-1.78 and HR=1.32, 95% CI=1.08-1.60, respectively) after multivariable adjustment, whereas LFN showed a marginal association with increased CVD events risk (HR=1.16, 95% CI=0.98-1.37) but not with dementia (HR=1.09, 95%CI=0.86-1.38).

Conclusion and Relevance

We identified three distinct multidimensional profiles of sleep health. Compared to healthy sleepers, older men with overall poor sleep and circadian activity rhythms exhibited worse incident cognitive and cardiovascular health. These results highlight potential targets for sleep interventions and the need for more comprehensive screening of poor sleepers for adverse outcomes.

Sedum kamtschaticum Exerts Hypnotic Effects via the Adenosine A2A Receptor in Mice

Insomnia is a common sleep disorder with significant societal and economic impacts. Current pharmacotherapies for insomnia are often accompanied by side effects, necessitating the development of new therapeutic drugs. In this study, the hypnotic effects and mechanisms of Sedum kamtschaticum 30% ethanol extract (ESK) and one of its active compounds, myricitrin, were investigated using pentobarbital-induced sleep experiments, immunohistochemistry (IHC), receptor binding assays, and enzyme-linked immunosorbent assay (ELISA). The pentobarbital-induced sleep experiments revealed that ESK and myricitrin reduced sleep latency and prolonged total sleep time in a dose-dependent manner. Based on c-Fos immunostaining, ESK, and myricitrin enhanced the GABAergic neural activity in sleep-promoting ventrolateral preoptic nucleus (VLPO) GABAergic. By measuring the level of GABA released from VLPO GABAergic neurons, ESK and myricitrin were found to increase GABA release in the hypothalamus. These effects were significantly inhibited by SCH. Moreover, ESK exhibited a concentration-dependent binding affinity for the adenosine A2A receptors (A2AR). In conclusion, ESK and myricitrin have hypnotic effects, and their underlying mechanisms may be related to the activation of A2AR.

The association between Weight-adjusted-Waist Index (WWI) and cognitive function in older adults: a cross-sectional NHANES 2011-2014 study

BACKGROUND

The impact of obesity on cognitive function has engendered considerable interest. Weight-adjusted waist index (WWI) has emerged as a novel and innovative marker of obesity that reflects weight-independent abdominal obesity. However, the association between WWI and cognitive function remains unclear. To address this gap, the present study aims to explore the relationship between weight-adjusted waist index (WWI) and cognitive performance in older adults.

METHODS

We conducted a cross-sectional investigation using datasets from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. The study included 3,472 participants (48.59% male, 51.41% female) of various races (Mexican American, Other Hispanic, Non-Hispanic White, Non-Hispanic Black, and Other), with a mean age of 69.95 years (SD = 6.94). Multivariate regression and smoothing curve fitting were used to investigate the linear and nonlinear relationship between WWI and cognitive performance in the following domains: learning and memory, verbal fluency, and processing speed, as measured by Consortium to Establish a Registry for Alzheimer's Disease Word Learning subtest (CERAD-WL), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST), respectively. Subgroup analysis and interaction tests were conducted to examine the stability of this relationship across groups. Machine learning models based on random forests were used to analyze the predictive performance of WWI for cognitive function.

RESULTS

A total of 3,472 participants were included in the analysis. The results revealed significant negative associations between WWI and low scores on the CERAD-WL [-0.96 (-1.30, -0.62)], AFT [-0.77 (-1.05, -0.49)], and DSST [-3.67 (-4.55, -2.79)]. This relationship remained stable after converting WWI to a categorical variable. In addition, this significant negative association was more pronounced in men than women and diminished with advancing age. Non-linear threshold effects were observed, with correlations intensifying between WWI and CERAD-WL when WWI surpassed 12.25, AFT when WWI surpassed 11.54, and DSST when WWI surpassed 11.66.

CONCLUSIONS

A higher WWI, indicating increased abdominal obesity, was associated with deficits in learning, memory, verbal fluency, and processing speed among older adults. These findings suggest that abdominal obesity may play a crucial role in cognitive decline in this population. The stronger relationship observed between WWI and cognition in men highlights the need for gender-specific considerations in interventions targeting abdominal obesity. The results demonstrate the importance of interventions targeting abdominal obesity to preserve cognitive performance in older adults.

The impacts of sex and the 5xFAD model of Alzheimer's disease on the sleep and spatial learning responses to feeding time

Introduction

The relationships between the feeding rhythm, sleep and cognition in Alzheimer's disease (AD) are incompletely understood, but meal time could provide an easy-to-implement method of curtailing disease-associated disruptions in sleep and cognition. Furthermore, known sex differences in AD incidence could relate to sex differences in circadian rhythm/sleep/cognition interactions.

Methods

The 5xFAD transgenic mouse model of AD and non-transgenic wild-type controls were studied. Both female and male mice were used. Food access was restricted each day to either the 12-h light phase (light-fed groups) or the 12-h dark phase (dark-fed groups). Sleep (electroencephalographic/electromyographic) recording and cognitive behavior measures were collected.

Results

The 5xFAD genotype reduces NREM and REM as well as the number of sleep spindles. In wild-type mice, light-fed groups had disrupted vigilance state amounts, characteristics, and rhythms relative to dark-fed groups. These feeding time differences were reduced in 5xFAD mice. Sex modulates these effects. 5xFAD mice display poorer spatial memory that, in female mice, is curtailed by dark phase feeding. Similarly, female 5xFAD mice have decreased anxiety-associated behavior. These emotional and cognitive measures are correlated with REM amount.

Discussion

Our study demonstrates that the timing of feeding can alter many aspects of wake, NREM and REM. Unexpectedly, 5xFAD mice are less sensitive to these feeding time effects. 5xFAD mice demonstrate deficits in cognition which are correlated with REM, suggesting that this circadian-timed aspect of sleep may link feeding time and cognition. Sex plays an important role in regulating the impact of feeding time on sleep and cognition in both wild-type and 5xFAD mice, with females showing a greater cognitive response to feeding time than males.

Leisure-time physical activity as a key protective factor against cognitive decline in older adults: an isotemporal substitution analysis

This study aimed to test hypothesized effects of replacing sedentary behavior with moderate-to-vigorous physical activity, sleep, and different domains of physical activity by equivalent amounts on suggestive cognitive decline in an older adult population. This was a cross-sectional study including 473 older adults aged ≥ 60 years. Cognitive decline was assessed using the Mini-Mental Health Examination. Physical activity, its different domains and the time of exposure to sedentary behavior were assessed using the International Physical Activity Questionnaire. For data analysis, two isotemporal substitution models were constructed using Poisson regression. The first model tested the effect of sleep time, sedentary behavior, and moderate-to-vigorous physical activity on cognitive decline. The second model was used to determine the effect of physical activity domains (leisure, work, transport, and home), sleep time, and sedentary behavior on cognitive decline. Physical activity during leisure time was protective against cognitive decline among all domains tested, replacing sedentary behavior, sleep, and transport. Conversely, substitution of the leisure domain for sedentary behavior, sleep, and transport was considered a risk factor for cognitive decline. Leisure time proved to be a strong protective factor in reducing the risk of cognitive decline, and it is necessary to encourage and stimulate public policies that include it.