Sleep Disturbance, Cognitive Decline, and Dementia: A Review

The prevalence of sleep disturbance and its possible associated factors among iranian medical students: A cross-sectional study with a national meta-analysis

Background

The aim of this cross-sectional study was to investigate the prevalence of sleep disturbance and its possible associated factors among Iranian medical students. Additionally, a national meta-analysis was conducted to provide a comprehensive overview of sleep disturbance in this population.

Methods

A sample of medical students from Guilan University of Medical Sciences, Iran was included in the study. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep disturbance. Demographic and lifestyle factors, as well as academic performance, were collected through a self-administered questionnaire. The data collected from this study were combined with existing studies through a meta-analysis to estimate the overall prevalence of sleep disturbance among Iranian medical students using the random effects model.

Results

A total of 249 medical students participated in the study. The prevalence of sleep disturbance among Guilan University of Medical Sciences medical students was found to be 71.1%. A significant difference was observed in total PSQI means regarding medical students' residency (p < 0.001) and their duration of sleep in the last 24 h (p = 0.006). The national prevalence of sleep disturbances was 59% (95% CI: [51%-66%], I2 = 97%).

Conclusion

Sleep disturbance is highly prevalent among Iranian medical students, with various factors contributing to its occurrence. The findings of this study highlight the need for interventions and strategies to improve sleep quality and overall well-being among this population. The national meta-analysis provides valuable insights into the overall burden of sleep disturbance among Iranian medical students and can serve as a reference for future studies and public health initiatives targeting this issue.

Association between sleep problems and impulsivity mediated through regional homogeneity abnormalities in male methamphetamine abstainers

Sleep problems and impulsivity frequently occur in methamphetamine (MA) abstainers and are linked to aberrant brain function. However, the interplay between these factors remains poorly understood. This study aimed to investigate the relationship between sleep, impulsivity, and regional homogeneity (ReHo) through mediation analysis in MA abstainers. 46 MA abstainers and 44 healthy controls were included. Impulsivity and sleep problems were evaluated using the Barratt Impulsivity Scale and the Pittsburgh Sleep Quality Scale, respectively. ReHo, indicative of local brain spontaneous neural activity, was assessed using resting-state functional magnetic resonance imaging. Results unveiled correlations between different dimensions of impulsivity and ReHo values in specific brain regions. Motor impulsivity correlated with ReHo values in the left postcentral gyrus and left precentral gyrus, while non-planning impulsivity was only associated with ReHo values in the left precentral gyrus. Additionally, the need for sleep medications correlated with ReHo values in the left precentral gyrus and bilateral postcentral gyrus. Also, the need for sleep medications was positively correlated with cognitive impulsivity and motor impulsivity. Mediation analysis indicated that reduced ReHo values in the left precentral gyrus mediated the association between impulsivity and the need for sleep medications. These findings imply that addressing sleep problems, especially the need for sleep medications, might augment spontaneous neural activity in specific brain regions linked to impulsivity among MA abstainers. This underscores the importance of integrating sleep interventions into comprehensive treatment strategies for MA abstainers.

Longitudinal associations between biopsychosocial stress indicators and sleep in older Puerto Rican adults

OBJECTIVES

To examine the association of biopsychosocial stress indicators (perceived stress, perceived discrimination, stressful life events, and allostatic load) with sleep outcomes (sleep duration and insomnia symptoms) and to examine sex and age interactions for associations between stress and sleep in older Puerto Rican adults.

METHODS

Secondary analyses were performed with 830 participants (72% female) from wave 2 (2006-2011) of the Boston Puerto Rican Health Study (BPRHS), a prospective population-based cohort study (45-75years at baseline) and Boston Puerto Rican Osteoporosis Study (BPROS) (2007-2012), an ancillary study of the BPRHS. Recruitment occurred in randomly selected census blocks using door-to-door and community-based activities. In-home data collection visits included a baseline assessment and follow-up interviews. Questionnaires assessed perceived stress, discrimination, stressful life events, and sleep. Allostatic load indicators were measured objectively. Regression models controlled for sociodemographic, behavioral, and health factors, with interaction analyses, followed by sex- and sex-by-age-stratified analyses.

RESULTS

In the prior 2years, participants with chronic stress had 50% greater odds of reporting nonoptimal sleep duration (<7 or >9 hours). Life events trajectories were significantly related to insomnia symptoms. Men ≥65years who experienced chronic stress had greater insomnia symptoms than women, or than men with low stress or acute stress.

CONCLUSIONS

Stressful life events may affect sleep duration and insomnia symptoms among older Puerto Rican adults, particularly men 65 years and older who experienced chronic stress. Given the differences in sleep patterns experienced by older adults and their relationships with health outcomes, identifying methods to support sleep health among those with chronic stress is important.

Mixture of Rhodiola rosea and Nelumbo nucifera Extracts Ameliorates Sleep Quality of Adults with Sleep Disturbance

Chronic sleep disturbance affects daily functioning, leading to decreased concentration, fatigue, and higher healthcare costs. Traditional insomnia medications are often associated with adverse side effects. This study investigated the efficacy of a novel compound derived from Rhodiola rosea and Nelumbo nucifera extracts (named RNE) in improving sleep quality with fewer side effects. The study included individuals between the ages of 20 and 65 with subthreshold insomnia and evaluated the effects of RNE on sleep, fatigue, and quality of life. Participants took 750 mg of RNE daily at bed-time for two weeks. The study used the Insomnia Severity Index (ISI), the Pittsburgh Sleep Quality Index (PSQI), a sleep diary, the Fatigue Severity Scale (FSS), and the Short Form 36 Health Survey (SF-36) for assessments. Of the 20 participants, 13 completed the study and showed significant improvements in sleep quality. The results showed improvements in ISI and PSQI scores, a 57% reduction in wake-time after sleep onset, and improved sleep efficiency. Although FSS scores remained unchanged, significant improvements were seen in SF-36 physical and mental health scores. The results suggest that RNE is an effective, low-risk option for sleep disturbance, significantly improving sleep quality and overall wellbeing without significant side effects.

Association between sleep apnoea and risk of cognitive impairment and Alzheimer's disease: a meta-analysis of cohort-based studies

PURPOSE

To provide updated evidence on the association of obstructive sleep apnoea (OSA)/sleep-disordered breathing (SDB) with risk of all-cause cognitive impairment/dementia and Alzheimer's disease (AD).

METHODS

A systematic literature search was done in PubMed, EMBASE and Scopus databases for cohort studies (retrospective or prospective) that documented the association of SDB/OSA with the risk of cognitive impairment or all-cause dementia or AD. Only studies that were published in the year 2000 and onwards were included. The random-effects model was used for all the analyses and effect sizes were reported as hazards ratio (HR) with 95% confidence intervals.

RESULTS

Of 15 studies were included in the meta-analysis, SDB/OSA was diagnosed with at-home polysomnography in six studies, while five studies relied on self-report or questionnaires. In the remaining studies, International Classification of Diseases (ICD) codes determined the diagnosis of SDB. The overall pooled analysis showed that patients with SDB/OSA had higher risk of cognitive impairment and/or all-cause dementia (HR 1.52, 95% CI: 1.32, 1.74), when compared to patients without SDB/OSA. However, when studies with diagnosis of SDB based on polysomnography were pooled together, the strength of association for all-cause cognitive impairment was weaker (HR 1.32, 95% CI: 1.00, 1.74).

CONCLUSION

Findings suggest a possible association of SDB/OSA with risk of all-cause cognitive impairment and/or dementia. However, careful interpretation is warranted as the majority of the studies did not rely on objective assessment based on polysomnography.

Prospective cohort study of long-term neurological outcomes in retired elite athletes: the Advanced BiomaRker, Advanced Imaging and Neurocognitive (BRAIN) Health Study protocol

INTRODUCTION

Although limited, recent research suggests that contact sport participation might have an adverse long-term effect on brain health. Further work is required to determine whether this includes an increased risk of neurodegenerative disease and/or subsequent changes in cognition and behaviour. The Advanced BiomaRker, Advanced Imaging and Neurocognitive Health Study will prospectively examine the neurological, psychiatric, psychological and general health of retired elite-level rugby union and association football/soccer players.

METHODS AND ANALYSIS

400 retired athletes will be recruited (200 rugby union and 200 association football players, male and female). Athletes will undergo a detailed clinical assessment, advanced neuroimaging, blood testing for a range of brain health outcomes and neuropsychological assessment longitudinally. Follow-up assessments will be completed at 2 and 4 years after baseline visit. 60 healthy volunteers will be recruited and undergo an aligned assessment protocol including advanced neuroimaging, blood testing and neuropsychological assessment. We will describe the previous exposure to head injuries across the cohort and investigate relationships between biomarkers of brain injury and clinical outcomes including cognitive performance, clinical diagnoses and psychiatric symptom burden.

ETHICS AND DISSEMINATION

Relevant ethical approvals have been granted by the Camberwell St Giles Research Ethics Committee (Ref: 17/LO/2066). The study findings will be disseminated through manuscripts in clinical/academic journals, presentations at professional conferences and through participant and stakeholder communications.

Informal carers' experiences in everyday life and the use of digital assistive technology for time management in persons with dementia or mild cognitive impairment

BACKGROUND

Digital assistive technology (DAT) may support time management in people with dementia or mild cognitive impairment (MCI), but research on DAT for time management is limited. We aimed to explore how everyday could be supported by DAT for time management in persons with dementia or MCI from informal carers' perspectives. This study focused on a DAT device for time management called MEMOplanner (MMP).

METHOD

Using a mixed-methods design, we utilized the Time-Proxy© questionnaire and a study-specific interview guide to investigate the perspectives of informal carers (n = 8) regarding the use of MMP by individuals with dementia or MCI.

RESULT

The MMP was helpful in keeping track of time and activity. It helped to maintain an active lifestyle and facilitated communication. However, the MMP did not reduce the need for assistance from the informal carers, and it took time to learn the different functions of the device. Further research into employing a more extensive array of DAT for time management or other areas to assist individuals with dementia will yield valuable insights into enhancing and sustaining a higher quality of life despite cognitive decline.

Association of vitamin B1 intake with geriatric cognitive function: An analysis of the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014

Background

The association between dietary vitamin B1 intake and cognitive performance in the noninstitutionalized older adult population of the United States remains unclear.

Purpose

This study aimed to investigate the association between vitamin B1 intake and cognitive performance in older adults in the United States.

Methods

Vitamin B1 intake was assessed through two 24-h dietary recalls. Weighted logistic regression was used to evaluate the association between vitamin B1 intake and three cognitive scores (immediate recall test [IRT], animal fluency test [AFT], and digit symbol substitution test [DSST]). Cognitive performance was measured by these three tests, and individuals scoring below the lowest quartile were categorized as cognitive impairment. Sensitivity analysis, including dose-response curves, subgroup analyses, interaction effects, per 1 SD, and quartiles, were performed to ensure the accuracy of the conclusion.

Results

A total of 2896 participants over the age of 60 were included in this study. In the adjusted final model, the association between vitamin B1 intake and low cognitive performance in old age was statistically significant, with the following odds ratios (ORs) and 95% confidence intervals (CIs): IRT, 0.75 (0.57, 0.97), P = 0.018; AFT, 0.68 (0.50, 0.92), P = 0.007; DSST, 0.71 (0.54, 0.92), P = 0.005. Subgroup analyses showed that this association was statistically significant among males, white, low-education, and no memory impairment. The results of the sensitivity analyses confirmed the association between VB1 and cognitive function in old age and the absence of interactions in the final calibrated model.

Conclusion

Dietary vitamin B1 intake is negatively associated with cognitive performance in older adults.

Relative associations of behavioral and physiological risks for cardiometabolic disease with cognition in bipolar disorder during mid and later-life: findings from the UK biobank

BACKGROUND

Cardiometabolic disease risk factors are disproportionately prevalent in bipolar disorder (BD) and are associated with cognitive impairment. It is, however, unknown which health risk factors for cardiometabolic disease are relevant to cognition in BD. This study aimed to identify the cardiometabolic disease risk factors that are the most important correlates of cognitive impairment in BD; and to examine whether the nature of the relationships vary between mid and later life.

METHODS

Data from the UK Biobank were available for 966 participants with BD, aged between 40 and 69 years. Individual cardiometabolic disease risk factors were initially regressed onto a global cognition score in separate models for the following risk factor domains; (1) health risk behaviors (physical activity, sedentary behavior, smoking, and sleep) and (2) physiological risk factors, stratified into (2a) anthropometric and clinical risk (handgrip strength, body composition, and blood pressure), and (2b) cardiometabolic disease risk biomarkers (CRP, lipid profile, and HbA1c). A final combined multivariate regression model for global cognition was then fitted, including only the predictor variables that were significantly associated with cognition in the previous models.

RESULTS

In the final combined model, lower mentally active and higher passive sedentary behavior, higher levels of physical activity, inadequate sleep duration, higher systolic and lower diastolic blood pressure, and lower handgrip strength were associated with worse global cognition.

CONCLUSIONS

Health risk behaviors, as well as blood pressure and muscular strength, are associated with cognitive function in BD, whereas other traditional physiological cardiometabolic disease risk factors are not.

Sleep loss disrupts decision-making ability and neuronal cytomorphology in zebrafish and the effects are mediated by noradrenaline acting on α1-adrenoceptor

Sleep is an instinct behavior, and its significance and functions are still an enigma. It is expressed throughout one's life and its loss affects psycho-somatic and physiological processes. We had proposed that it might maintain a fundamental property of the neurons and the brain. In that context, it was shown that sleep, rapid eye movement sleep (REMS) in particular, by regulating noradrenaline (NA), maintains the brain excitability. It was also reported that sleep-loss affected memory, reaction time and decision-making ability among others. However, as there was lack of clarity on the cause-and-effect relationship as to how the sleep-loss could affect these basic behaviors, their association was questioned and it was difficult to propose a cure or at least ways and means to ameliorate the symptoms. Also, we wanted to conduct the studies in a simpler model system so that conducting future molecular studies might be easier. Hence, using zebrafish as a model we evaluated if sleep-loss affected the basic decision-making ability, a cognitive process and if the effect was induced by NA. Indeed, our findings confirmed that upon sleep-deprivation, the cognitive decision-making ability of the prey zebrafish was compromised to protect itself by running away from the reach of the exposed predator Tiger Oscar (TO) fish. Also, we observed that upon sleep-loss the axonal arborization of the prey zebrafish brain was reduced. Interestingly, the effects were prevented by prazosin (PRZ), an α1-adrenoceptor (AR) antagonist and when the zebrafish recovered from the lost sleep.

The parent and family impact of CLN3 disease: an observational survey-based study

BACKGROUND

CLN3 disease (also known as CLN3 Batten disease or Juvenile Neuronal Ceroid Lipofuscinosis) is a rare pediatric neurodegenerative disorder caused by biallelic mutations in CLN3. While extensive efforts have been undertaken to understand CLN3 disease etiology, pathology, and clinical progression, little is known about the impact of CLN3 disease on parents and caregivers. Here, we investigated CLN3 disease progression, clinical care, and family experiences using semi-structured interviews with 39 parents of individuals with CLN3 disease. Analysis included response categorization by independent observers and quantitative methods.

RESULTS

Parents reported patterns of disease progression that aligned with previous reports. Insomnia and thought- and mood-related concerns were reported frequently. "Decline in visual acuity" was the first sign/symptom noticed by n = 28 parents (70%). A minority of parents reported "behavioral issues" (n = 5, 12.5%), "communication issues" (n = 3, 7.5%), "cognitive decline" (n = 1, 2.5%), or "seizures" (n = 1, 2.5%) as the first sign/symptom. The mean time from the first signs or symptoms to a diagnosis of CLN3 disease was 2.8 years (SD = 4.1). Misdiagnosis was common, being reported by n = 24 participants (55.8%). Diagnostic tests and treatments were closely aligned with observed symptoms. Desires for improved or stabilized vision (top therapeutic treatment concern for n = 14, 32.6%), cognition (n = 8, 18.6%), and mobility (n = 3, 7%) dominated parental concerns and wishes for therapeutic correction. Family impacts were common, with n = 34 (81%) of respondents reporting a financial impact on the family and n = 20 (46.5%) reporting marital strain related to the disease.

CONCLUSIONS

Collectively, responses demonstrated clear patterns of disease progression, a strong desire for therapies to treat symptoms related to vision and cognition, and a powerful family impact driven by the unrelenting nature of disease progression.

Impaired sleep is associated with tau deposition on 18F-flortaucipir PET and accelerated cognitive decline, accounting for medications that affect sleep

BACKGROUND

Impaired sleep is commonly associated with Alzheimer's disease (AD), although the underlying mechanisms remain unclear. Furthermore, the moderating effects of sleep-affecting medications, which have been linked to AD pathology, are incompletely characterized. Using data from the Alzheimer's Disease Neuroimaging Initiative, we investigated whether a medical history of impaired sleep, informant-reported nighttime behaviors, and sleep-affecting medications are associated with beta-amyloid and tau deposition on PET and cognitive change, cross-sectionally and longitudinally.

METHODS

We included 964 subjects with 18F-florbetapir PET scans. Measures of sleep impairment and medication use were obtained from medical histories and the Neuropsychiatric Inventory Questionnaire. Multivariate models, adjusted for covariates, were used to assess associations among sleep-related features, beta-amyloid and tau, and cognition. Cortical tau deposition, categorized by Braak stage, was assessed using the standardized uptake value peak alignment (SUVP) method on 18F-flortaucipir PET.

RESULTS

Medical history of sleep impairment was associated with greater baseline tau in the meta-temporal, Braak 1, and Braak 4 regions (p = 0.04, p < 0.001, p = 0.025, respectively). Abnormal nighttime behaviors were also associated with greater baseline tau in the meta-temporal region (p = 0.024), and greater cognitive impairment, cross-sectionally (p = 0.007) and longitudinally (p < 0.001). Impaired sleep was not associated with baseline beta-amyloid (p > 0.05). Short-term use of selective serotonin reuptake inhibitors and benzodiazepines slightly weakened the sleep-tau relationship.

CONCLUSIONS

Sleep impairment was associated with tauopathy and cognitive decline, which could be linked to increased tau secretion from neuronal hyperactivity. Clinically, our results help identify high-risk individuals who could benefit from sleep-related interventions aimed to delay cognitive decline and AD.

Meditation Experience is Associated with Increased Structural Integrity of the Pineal Gland and greater total Grey Matter maintenance

Growing evidence demonstrates that meditation practice supports cognitive functions including attention and interoceptive processing, and is associated with structural changes across cortical networks including prefrontal regions, and the insula. However, the extent of subcortical morphometric changes linked to meditation practice is less appreciated. A noteworthy candidate is the Pineal Gland, a key producer of melatonin, which regulates circadian rhythms that augment sleep-wake patterns, and may also provide neuroprotective benefits to offset cognitive decline. Increased melatonin levels as well as increased fMRI BOLD signal in the Pineal Gland has been observed in mediators vs. controls. However, it is not known if long-term meditators exhibit structural change in the Pineal Gland linked to lifetime duration of practice. In the current study we performed Voxel-based morphometry (VBM) analysis to investigate: 1) whether long-term meditators (LTMs) (n=14) exhibited greater Pineal Gland integrity compared to a control group (n=969), 2) a potential association between the estimated lifetime hours of meditation (ELHOM) and Pineal Gland integrity, and 3) whether LTMs show greater Grey Matter (GM) maintenance (BrainPAD) that is associated with Pineal Gland integrity. The results revealed greater Pineal Gland integrity and lower BrainPAD scores (younger brain age) in LTMs compared to controls. Exploratory analysis revealed a positive association between ELHOM and greater signal intensity in the Pineal Gland but not with GM maintenance as measured by BrainPAD score. However, greater Pineal integrity and lower BrainPAD scores were correlated in LTMs. The potential mechanisms by which meditation influences Pineal Gland function, hormonal metabolism, and GM maintenance are discussed - in particular melatonin's roles in sleep, immune response, inflammation modulation, and stem cell and neural regeneration.

The amyloid precursor protein intracellular domain induces sleep disruptions and its nuclear localization fluctuates in circadian pacemaker neurons in Drosophila and mice

The most prominent symptom of Alzheimer's disease (AD) is cognitive decline; however, sleep and other circadian disruptions are also common in AD patients. Sleep disruptions have been connected with memory problems and therefore the changes in sleep patterns observed in AD patients may also actively contribute to cognitive decline. However, the underlying molecular mechanisms that connect sleep disruptions and AD are unclear. A characteristic feature of AD is the formation of plaques consisting of Amyloid-β (Aβ) peptides generated by cleavage of the Amyloid Precursor Protein (APP). Besides Aβ, APP cleavage generates several other fragments, including the APP intracellular domain (AICD) that has been linked to transcriptional regulation and neuronal homeostasis. Here we show that overexpression of the AICD reduces the early evening expression of two core clock genes and disrupts the sleep pattern in flies. Analyzing the subcellular localization of the AICD in pacemaker neurons, we found that the AICD levels in the nucleus are low during daytime but increase at night. While this pattern of nuclear AICD persisted with age, the nighttime levels were higher in aged flies. Increasing the cleavage of the fly APP protein also disrupted AICD nuclear localization. Lastly, we show that the day/nighttime nuclear pattern of the AICD is also detectable in neurons in the suprachiasmatic nucleus of mice and that it also changes with age. Together, these data suggest that AD-associated changes in APP processing and the subsequent changes in AICD levels may cause sleep disruptions in AD.

Joint associations of sleep duration and physical activity with cognitive impairment among rural elderly over 65 years old: a cross-sectional study

BACKGROUND

During the long preclinical phase of dementia, accelerated cognitive impairment is regarded as a cardinal marker. Thus, the identification of risk factors for cognitive impairment is of great significance for dementia prevention. This study aims to examine the joint associations of sleep duration and physical activity with cognitive impairment among rural elderly over 65 years old, and provide suggestions for improving the cognitive function in rural elderly over 65 years old.

METHODS

A cross-sectional study was conducted in rural Nanjing by recruiting 1147 individuals aged above 65 years. Cognitive function was assessed using the brief community screening instrument for dementia. Physical activity was assessed using the Global Physical Activity Questionnaire. Data were analyzed by multivariate logistic regression models, and a significant difference was set at P < 0.05.

RESULTS

Compared with participants with proper sleep duration and sufficient physical activity, participants with short sleep duration and insufficient physical activity (odds ratio (OR): 1.820; 95% CI: 1.265 ~ 2.618), long sleep duration and sufficient physical activity (OR: 2.428; 95% CI: 1.137 ~ 5.183) showed an increased likelihood of cognitive impairment.

CONCLUSIONS

Inappropriate sleep duration combined with insufficient physical activity was associated with a significantly higher likelihood of cognitive impairment in rural elderly over 65 years old.

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

STUDY OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL INFORMATION

Not applicable.

Interrelationship of Sleep Disturbances and Cognitive Status on Mortality

Sleep disturbances may promote the development and advancement of Alzheimer's disease. Our purpose was to determine if sleep disturbances were associated with earlier mortality while accounting for cognition. The National Alzheimer's Coordinating Center database was used to evaluate mortality risk conferred by sleep, and the Montreal Cognitive Assessment score determined cognitive status. Demographics, sleep disturbances, cognitive status, and comorbid/other neuropsychiatric conditions were examined as predictors of survival time via Cox regression. The sample (N = 31,110) had a median age [interquartile range] of 72 [66, 79] years, MoCA score of 23 [16, 26], and survival time of 106.0 months [104.0,108.0]; 10,278 (33%) died during follow-up; 21% (n = 6461) experienced sleep disturbances. Sleep disturbances impacted survival time depending on cognition, with the greatest effect in transition from normal to cognitive impairment (P < .001). Findings support that sleep disturbances negatively impact survival time, and the impact of sleep disturbances on survival time is interrelated with cognition.

Sleep structure assessed by objective measurement in patients with mild cognitive impairment: A meta-analysis

OBJECTIVES

A meta-analysis was used to explore the characteristic changes in objective sleep structure of patients with mild cognitive impairment (MCI) compared with cognitively healthy older adults.

MATERIALS AND METHODS

PubMed, EMBAS, Cochrane Library, Scopus, and Web of Science were searched until November 2023. A literature quality evaluation was performed according to the Newcastle-Ottawa Scale, and a meta-analysis was performed by RevMan 5.3 software.

RESULTS

Fifteen studies with 771 participants were finally included. Compared with normal control groups, patients with MCI had a decreased total sleep time by 34.44 min, reduction in sleep efficiency by 7.96 %, increased waking after sleep onset by 19.61 min, and increased sleep latency by 6.97 min. Ten included studies showed that the patients with MCI had increased N1 sleep by 2.72 % and decreased N3 sleep by 0.78 %; however, there was no significant difference between the MCI and control groups in percentage of N2 sleep. Moreover, Twelve included studies reported the MCI groups had shorter REM sleep of 2.69 %.

CONCLUSION

Our results provide evidence of abnormal sleep architecture in patients with MCI. As a "plastic state," abnormal sleep architecture may be a promising therapeutic target for slowing cognitive decline and dementia prevention.

Sex and Sleep Disruption as Contributing Factors in Alzheimer's Disease

Alzheimer's disease (AD) affects more women than men, with women throughout the menopausal transition potentially being the most under researched and at-risk group. Sleep disruptions, which are an established risk factor for AD, increase in prevalence with normal aging and are exacerbated in women during menopause. Sex differences showing more disrupted sleep patterns and increased AD pathology in women and female animal models have been established in literature, with much emphasis placed on loss of circulating gonadal hormones with age. Interestingly, increases in gonadotropins such as follicle stimulating hormone are emerging to be a major contributor to AD pathogenesis and may also play a role in sleep disruption, perhaps in combination with other lesser studied hormones. Several sleep influencing regions of the brain appear to be affected early in AD progression and some may exhibit sexual dimorphisms that may contribute to increased sleep disruptions in women with age. Additionally, some of the most common sleep disorders, as well as multiple health conditions that impair sleep quality, are more prevalent and more severe in women. These conditions are often comorbid with AD and have bi-directional relationships that contribute synergistically to cognitive decline and neuropathology. The association during aging of increased sleep disruption and sleep disorders, dramatic hormonal changes during and after menopause, and increased AD pathology may be interacting and contributing factors that lead to the increased number of women living with AD.

Self-Reported Sleep Duration and Bedtime Are Associated with Dementia Risk in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study

Background

Sleep is a potentially modifiable factor associated with dementia, including Alzheimer's disease, but current evidence supporting this is insufficient.

Objective

This study aimed to determine whether sleep duration and bedtime patterns are associated with the risk of dementia among middle-aged and older people.

Methods

This cohort study had an eight-year follow-up period. Participants were 13,601 community-dwelling people aged 40-74 years living in Murakami (Niigata, Japan). Data were collected using a self-administered questionnaire. Predictors were self-reported sleep duration and bedtime, and the outcome was newly-diagnosed dementia determined using the long-term care insurance database. Covariates were demographic characteristics, body mass index, smoking, alcohol consumption, total physical activity, insomnia symptoms, disease history, and either bedtime or sleep duration. Cox proportional hazard models were used to calculate hazard ratios (HRs).

Results

The mean age of participants at baseline was 59.2 years. Over a mean follow-up period of 8.0 years, 319 cases of dementia were observed. A long self-reported sleep duration relative to the reference sleep duration (7 hours) was associated with increased dementia risk, with the "8 hours" group (adjusted HR = 1.30, 95% CI:0.99-1.73) and "≥9 hours" group (adjusted HR = 1.46, 95% CI:1.00-2.15) having an increased risk (marginally significant) relative to the reference group. Early bedtime was associated with increased dementia risk (adjusted p for trend = 0.0010), with the "21 : 00 or earlier" group (adjusted HR = 1.61, 95% CI:1.14-2.28) having an increased risk relative to the reference ("23 : 00").

Conclusions

A long self-reported sleep duration and early bedtime are both associated with increased dementia risk in middle-aged and older people.

APOE-ε4 Alleles Modify the Decline of MMSE Scores Associated With Time-Dependent PM2.5 Exposure: Findings From a Community-Based Longitudinal Cohort Study

OBJECTIVE

Limited research has explored the long-term effect of reduced PM2.5 exposure on cognitive function. This study aimed to investigate the effects of time-dependent PM2.5 exposure and the interactions of PM2.5 and aging on declines in Mini-Mental State Examination (MMSE) scores, in carriers and non-carriers of the APOE-ε4 allele.

METHODS

Participants aged over 60 were recruited for this cohort study, undergoing MMSE tests twice from the Taiwan Biobank Program from 2008 to 2020. Participants with dementia or baseline MMSE scores <24 were excluded. Annual PM2.5 levels were estimated using a hybrid kriging/land use regression model with extreme gradient boosting, treated as a time-dependent variable. Generalized estimating equations were used to assess the impacts of repeated PM2.5 on MMSE decline, further stratified by the presence of APOE-ε4 alleles.

RESULTS

After follow-up, 290 participants out of the overall 7,000 community residents in the Biobank dataset demonstrated incidences of MMSE declines (<24), with an average MMSE score decline of 1.11 per year. Participants with ε4/ε4 alleles in the APOE gene had significantly 3.68-fold risks of MMSE decline. High levels of PM2.5 across all visits were significantly associated with worsening of scores on the overall MMSE. As annual levels of PM2.5 decreased over time, the impact of PM2.5 on MMSE decline also slowly diminished.

CONCLUSION

Long-term PM2.5 exposure may be associated with increased risk of MMSE decline, despite improvements in ambient PM2.5 levels over time. Validation of these results necessitates a large-scale prospective cohort study with more concise cognitive screening tools.

Sleep Deficits Inter-Link Lower Basal Forebrain-Posterior Cingulate Connectivity and Perceived Stress and Anxiety Bidirectionally in Young Men

BACKGROUND

The basal nucleus of Meynert (BNM), a primary source of cholinergic projections to the cortex, plays key roles in regulating the sleep-wake cycle and attention. Sleep deficit is associated with impairment in cognitive and emotional functions. However, whether or how cholinergic circuit, sleep, and cognitive/emotional dysfunction are inter-related remains unclear.

METHODS

We curated the Human Connectome Project data and explored BNM resting state functional connectivities (rsFC) in relation to sleep deficit, based on the Pittsburgh Sleep Quality Index (PSQI), cognitive performance, and subjective reports of emotional states in 687 young adults (342 women). Imaging data were processed with published routines and evaluated at a corrected threshold. We assessed the correlation between BNM rsFC, PSQI, and clinical measurements with Pearson regressions and their inter-relationships with mediation analyses.

RESULTS

In whole-brain regressions with age and alcohol use severity as covariates, men showed lower BNM rsFC with the posterior cingulate cortex (PCC) in correlation with PSQI score. No clusters were identified in women at the same threshold. Both BNM-PCC rsFC and PSQI score were significantly correlated with anxiety, perceived stress, and neuroticism scores in men. Moreover, mediation analyses showed that PSQI score mediated the relationship between BNM-PCC rsFC and these measures of negative emotions bidirectionally in men.

CONCLUSIONS

Sleep deficit is associated with negative emotions and lower BNM rsFC with the PCC. Negative emotional states and BNM-PCC rsFC are bidirectionally related through poor sleep quality. These findings are specific to men, suggesting potential sex differences in the neural circuits regulating sleep and emotional states.

Multi-modal sleep intervention for community-dwelling people living with dementia and primary caregiver dyads with sleep disturbance: protocol of a single-arm feasibility trial

Background

Disturbed sleep is common among people living with dementia and their informal caregivers, and is associated with negative health outcomes. Dyadic, multi-modal interventions targeting caregiver and care-recipient sleep have been recommended yet remain limited. This protocol details the development of a single-arm feasibility trial of a multi-modal, therapist-led, six-week intervention targeting sleep disturbance in dyads of people living with dementia and their primary caregiver.

Methods

We aim to recruit 24 co-residing, community-dwelling dyads of people living with dementia and their primary informal caregiver (n = 48) with sleep concerns (Pittsburgh Sleep Quality Index ≥5 for caregivers, and caregiver-endorsed sleep concerns for the person living with dementia). People who live in residential care settings, are employed in night shift work, or are diagnosed with current, severe mental health conditions or narcolepsy, will be excluded. Participants will wear an actigraph and complete sleep diaries for two weeks prior, and during the last two weeks, of active intervention. The intervention is therapist-led and includes a mix of weekly small group video sessions and personalised, dyadic sessions (up to 90 min each) over six weeks. Sessions are supported by a 37-page workbook offering strategies and spaces for reflections/notes. Primary feasibility outcomes are caregiver: session attendance, attrition, and self-reported project satisfaction. Secondary outcomes include dyadic self-reported and objectively-assessed sleep, depression and anxiety symptoms, quality of life, and social support. Self-report outcomes will be assessed at pre- and post-intervention.

Discussion

If feasible, this intervention could be tested in a larger randomised controlled trial to investigate its efficacy, and, upon further testing, may potentially represent a non-pharmacological approach to reduce sleep disturbance among people living with dementia and their caregivers.

ANZCTR Trial registration

ACTRN12622000144718: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382960&showOriginal=true&isReview=true.

The effect of light therapy on sleep disorders and psychobehavioral symptoms in patients with Alzheimer's disease: A meta-analysis

BACKGROUND

Although Alzheimer's disease (AD) mainly affects cognitive function, it is often accompanied by sleep disorders and psychobehavioral symptoms. These symptoms, including depression, agitation, and psychotic symptoms, are prominent hospitalization causes among patients with AD. Currently, relatively more research exists on light therapy for sleep disorders, while those on psychobehavioral symptoms are gradually increasing. However, no consensus exists on these results because of the vulnerability of light therapy to multiple factors, including light intensity and duration. Thus, further research investigating this aspect is warranted.

OBJECTIVE

To evaluate the efficacy of light therapy in improving sleep disorders and psychobehavioural symptoms in patients with AD.

METHODS

In this meta-analysis, relevant literature was searched in Embase, the Clinical Trials Registry, Web of Science, PubMed, and the Cochrane Library up to December 2022. Furthermore, a fixed-effects model was used for data analysis.

RESULTS

Fifteen randomized controlled trials involving 598 patients with AD were included. In the case of sleep disorders, our meta-analysis revealed that light therapy significantly improved sleep efficiency (MD = -2.42, 95% CI = -3.37 to -1.48, p < 0.00001), increased interdaily stability (MD = -0.04, 95% CI = -0.05 to -0.03, p < 0.00001), and reduced intradaily variability (MD = -0.07, 95% CI = -0.10 to -0.05, p < 0.00001). With respect to psychotic behavior, light therapy was found to alleviate depression (MD = -2.55, 95% CI = -2.98 to -2.12, p < 0.00001) as well as reduce agitation (MD = -3.97, 95% CI = -5.09 to -2.84, p < 0.00001) and caregiver burden (MD = -3.57, 95% CI = -5.28 to -1.87, p < 0.00001).

CONCLUSION

Light therapy leads to significant improvement in sleep and psychobehavioral symptoms and is associated with relatively fewer side effects in patients with AD, indicating its potential as a promising treatment option for AD.

An overview of neurocognitive impairment in older people living with HIV

Background

With improved survival among People Living with HIV (PLHIV), many are confronted with age associated comorbidities and geriatric syndromes. Neurocognitive impairment is one of the three most frequent conditions that affects quality of life of PLHIV despite achieving viral suppression. Healthcare providers face challenges in early identification of neurocognitive impairment, performing comprehensive assessment and managing older PLHIV.

Objectives

This paper aims to review available evidence regarding aetiology and management of older PLHIV who develop neurocognitive impairment, suggest improvements on current management and postulate future study direction.

Methods

A PubMed search for original articles and Clinical Guidelines was conducted from September 2021 to August 2022 using a combination of keywords related to neurocognitive impairment in PLHIV. The citations from all selected articles were reviewed for additional studies.

Results

Older PLHIV tend to be frailer than their uninfected counterparts, are plagued with multi-morbidity and are at increased risk of cognitive impairment. The aetiologies for neurocognitive impairment are multifactorial, multi-dimensional and complex. The management of neurocognitive impairment in older PLHIV involves identifying and optimizing predisposing factors, physical function, social and psychological health with appropriate care navigation.

Conclusion

Identification and management of neurocognitive impairment in older PLHIV through interdisciplinary collaboration among stakeholders is important. This exemplifies an integrated model of care for older PLHIV and promotes the notion of living well beyond viral suppression.

Association between sleep duration and hearing threshold shifts of adults in the United States: National Health and Nutrition Examination Survey, 2015-2016

BACKGROUND

Obstructive sleep apnea (OSA) is linked to hearing loss (HL). Another sleep characteristics, sleep duration might also be associated with HL, but prior evidence is limited. This study is aimed to investigate the association between sleep duration and hearing level in the adult US population.

METHODS

In total, a sample of 2777 individuals aged 20-69 years from the 2015-2016 National Health and Nutrition Examination Survey cycle (NHANES, 2015-2016) were investigated in this study. Self-reported sleep duration data was classified into the short-sleep (< 7 h), normal-sleep (7-9 h), and long-sleep (> 9 h) group. Multivariable linear regression models between sleep duration and hearing threshold shifts were estimated. Interactions between sleep duration and age, gender, race, OSA were also considered, and the study population was stratified by age, gender, race, and OSA to analyze the potential disparities among adults in different subgroups.

RESULTS

Long-sleep duration was positively associated with speech- and high-frequency pure-tone average (PTA) thresholds with statistical significance (β = 1.31, 95%CI: 0.10, 2.53, P = 0.0347, and β = 2.71, 95%CI: 0.69, 4.74, P = 0.0087, respectively). When stratified by age, short sleep duration was positively associated with low-, and speech-frequency PTAs (P = 0.0140 and 0.0225, respectively) for adults aged 40-59 years, and long-sleep duration was positively associated with low-, and speech-frequency PTAs (P = 0.0495 and 0.0142, respectively) for adults aged 60-69 years with statistical significance. There was statistically significant interaction between OSA and sleep duration on speech-frequency PTA, but no significant interaction between either gender or race with sleep duration on hearing thresholds among US adults.

CONCLUSION

Short/long sleep durations are associated with worse hearing level comparing to sleep 7-9 h in the American adults. Nonoptimal sleep duration may be a potential risk factor for HL.

Roles and usages of neuro service dogs for caregivers living at home with persons with dementia: An exploratory comparative case study

The goal of the present study was to examine how canine assistance may support family caregivers and persons with dementia and to document and compare two modalities of home care support. An exploratory comparative case study research design was conducted. Three cases correspond of dyads of a caregiver, a person with mild to moderate dementia, and either a neuro service dog (NSD), a companion dog or no dog. Hypotheses are formulated to capture differences between cases. Recruitment was done in a service dog organisation, through Canadian Alzheimer associations and in records of a hospital. Data were collected through 45-60 minutes telephone interviews that included completion of the Caregiver's Burden Scale and sociodemographic questions. We used an inductive approach with qualitative data. There were five caregivers (mean age 54.8 years) who had an NSD, 28 caregivers (63.6 years) who had a companion dog, and 23 caregivers (63.8 years) without dog. In the category of roles and usages of the dog, 'Socialisation' and 'Help with a sense of direction' were the most addressed roles for dyads with the NSD. For dyads with companion dog and without dog, 'Engagement-and-meaning of life' as well as 'Physical activity with the dog' were the most discussed roles. The 'Sleep or wake up' role was the least discussed role across three cases. In the other categories, they were seven advantages and 10 inconvenients that were mentioned for canine assistance. For home care support, the presence of NSD has more positive impacts on both the person with dementia and their caregiver compared to the presence of a companion dog; the presence of a NSD results in the person with dementia accessing more indoor and outdoor public sites than with a companion dog; and dyads with a dog are informally socially engaged more frequently than those with no dog.

Social Isolation, Sleep Disturbance, and Cognitive Functioning (HRS): A Longitudinal Mediation Study

BACKGROUND

Social isolation is prevalent and associated with dementia, yet the directionality and mechanisms are less understood. This study examined the association between social isolation and cognitive functioning and explored the mediating role of sleep disturbance on the social isolation-cognition relationship.

METHODS

Data from 5 753 dementia-free Americans aged ≥50 of 2006 (T1), 2010 (T2), and 2014 (T3) waves of the Health and Retirement Study. Social isolation was measured by the Steptoe Social Isolation Index. Cognitive functioning was measured by the Telephone Interview of Cognitive Status. Sleep disturbance was measured with the modified Jenkins Sleep Scale. We used cross-lagged panel models to determine the associations between social isolation, sleep disturbance, and cognitive functioning.

RESULTS

Social isolation is significantly associated with subsequent cognitive functioning (T1 to T2: β = -0.055, standard error [SE] = 0.014, p < .001; T2 to T3: β = -0.044, SE = 0.016, p < .001). Lower cognitive functioning is significantly associated with greater subsequent social isolation (T1 to T2: β = -0.101, SE = 0.020, p < .001; T2 to T3: β = -0.058, SE = .011, p < .001). Sleep disturbance at T2 partially mediated the effect of social isolation (T1) on cognitive functioning (T3), accounting for 6.2% of the total effect (β = -0.003, SE = 0.001, p < .01).

CONCLUSIONS

Social isolation may deteriorate cognitive functioning and vice versa. The association between social isolation and cognition is partially explained by sleep disturbance.

Sleep dysfunction mediates the relationship between hypothalamic-insula connectivity and anxiety-depression symptom severity bidirectionally in young adults

BACKGROUND

The hypothalamus plays a crucial role in regulating sleep-wake cycle and motivated behavior. Sleep disturbance is associated with impairment in cognitive and affective functions. However, how hypothalamic dysfunction may contribute to inter-related sleep, cognitive, and emotional deficits remain unclear.

METHODS

We curated the Human Connectome Project dataset and investigated how hypothalamic resting state functional connectivities (rsFC) were associated with sleep dysfunction, as evaluated by the Pittsburgh Sleep Quality Index (PSQI), cognitive performance, and subjective mood states in 687 young adults (342 women). Imaging data were processed with published routines and evaluated with a corrected threshold. We examined the inter-relationship amongst hypothalamic rsFC, PSQI score, and clinical measures with mediation analyses.

RESULTS

In whole-brain regressions with age and drinking severity as covariates, men showed higher hypothalamic rsFC with the right insula in correlation with PSQI score. No clusters were identified in women at the same threshold. Both hypothalamic-insula rsFC and PSQI score were significantly correlated with anxiety and depression scores in men. Further, mediation analyses showed that PSQI score mediated the relationship between hypothalamic-insula rsFC and anxiety/depression symptom severity bidirectionally in men.

CONCLUSIONS

Sleep dysfunction is associated with negative emotions and hypothalamic rsFC with the right insula, a core structure of the interoceptive circuits. Notably, anxiety-depression symptom severity and altered hypothalamic-insula rsFC are related bidirectionally by poor sleep quality. These findings are specific to men, suggesting potential sex differences in the neural circuits regulating sleep and emotional states that need to be further investigated.

Evaluation of Sleep Quality and Related Factors in Community-Dwelling Adults: Ardakan Cohort Study on Aging (ACSA)

BACKGROUND

Sleep is a necessary physiological process that affects health. The current study aimed to evaluate sleep quality (SQ) and the related factors in Iranian community-dwelling adults. Study Design: A cross-sectional study. Method: Population-based cross-sectional data from the first wave of the Ardakan cohort study on aging (ACSA) were analyzed. The analytical sample consisted of 5197 community-dwelling adults aged≥50. All data were collected by trained staff. Pittsburgh Sleep Quality Index (PSQI) scores were used to measure SQ. Univariable and multivariable logistic regression were used to identify predictors of SQ.

RESULTS

The mean age of the participants was 62.22±7.7 years, and 51.8% were female. About threequarters of them (76.36%) were found to have poor SQ (PSQI score≥5). Multivariable logistic regression analysis revealed a relationship between SQ and gender, education, work, and financial level. Furthermore, SQ was found to be associated with self-reported health and physical activity. Regarding comorbidity, SQ had a significant relationship with cardiovascular diseases, musculoskeletal diseases, depression, and anxiety (P<0.05).

CONCLUSION

The prevalence of poor SQ was high in these community-dwelling adults in Iran. These findings highlight the importance of intervention programs for sleep hygiene education and screening for middle-aged and older adults.

Serum Vitamin D3 Concentration, Sleep, and Cognitive Impairment among Older Adults in China

BACKGROUND

Cognitive decline in older adults has become one of the critical challenges to global health. This study aims to examine both cross-sectional and longitudinal associations of levels of serum 25-hydroxyvitamin D3 (25(OH)D3) (briefed as VD3) concentration and sleep quality/duration, especially their interactions, with risk of cognitive impairment among older adults in China.

METHODS

We utilized a special subsample of adults aged 65-105 years (individuals = 3412, observations = 4816) from eight provinces in China derived from the 2011/2012 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey. Cognitive impairment was measured by the Mini-Mental State Examination scale. Sleep quality was classified as good versus fair/poor, and sleep duration was classified into short (<7 h), normal (≥7 but <9 h), and long (≥9 h). The VD3 concentration was divided into three levels: deficiency (VD3 < 25 nmol/L), insufficiency (25 nmol/L ≤ VD3 < 50 nmol/L), and sufficiency (VD3 ≥ 50 nmol/L). A wide set of covariates that include demographics, socioeconomic status, family support, health practice, and health conditions was adjusted for robust findings. Multilevel random intercept logit regression models were used to examine the cross-sectional associations between VD3, sleep, and cognitive impairment, whereas logit regression models were applied to investigate the longitudinal associations.

RESULTS

In the cross-sectional analyses, when all covariates were adjusted, VD3 sufficiency was significantly associated with a 33% lower risk of cognitive impairment compared with VD3 deficiency; good sleep quality was associated with 34% lower odds of cognitive impairment compared with fair/poor sleep quality; sleep hours were not associated with cognitive impairment, although a long sleep duration (≥9 h) was associated with 30% higher odds of being cognitively impaired when baseline health was not controlled. Interaction analyses reveal that VD3 sufficiency could help to additionally reduce the risk of cognitive impairment for good sleep quality and normal sleep hours. In the longitudinal analyses, the association of VD3 sufficiency remains significant, whereas sleep quality and sleep duration were not significant associates.

CONCLUSIONS

Good sleep quality, normal sleep hours, and VD3 sufficiency are positively associated with good cognitive function. VD3 sufficiency could enhance the associations between sleep and cognitive impairment.

Puerarin alleviates sleep disorders in aged mice related to repairing intestinal mucosal barrier

More and more evidence suggests that puerarin, a potential remedy for gut inflammation, may have an ameliorative effect on sleep disturbances. However, the relationship between puerarin and sleep disruption has not been extensively researched. This study aims to explore the role and mechanisms of puerarin in improving sleep disorders. We established a light-induced sleep disorder model in mice and assessed the effects of puerarin on cognitive behavior using open field and water maze tests. Pathological detection demonstrated that sleep disturbances resulted in observable damage to the liver, lung, and kidney. Puerarin reversed multi-organ damage and inflammation. Further, puerarin activated paneth cells, resulting in increased lysozyme and TGF-β production, and stimulating intestinal stem cell proliferation. Puerarin also effectively inhibited the expression of F4/80, iNOS, TNF-α, and IL-1β in the small intestine, while it increased Chil3, CD206, and Arg-1 levels. Moreover, puerarin treatment significantly decreased P-P65, TLR4, Bcl-xl, and cleaved caspase-3 protein levels while increasing barrier protein levels, including ZO-1, Occludin, Claudin 1 and E-cadherin suggesting a reduction in inflammation and apoptosis in the gut. Overall, puerarin diminished systemic inflammation, particularly intestinal inflammation, and enhanced intestinal barrier integrity in mice with sleep disorders. Our findings suggest a potential new therapeutic pathway for sleep disorders.

Sleep Disorders Associated with Neurodegenerative Diseases

Sleep disturbances are common in various neurological pathologies, including amyotrophic lateral sclerosis (ALS), multiple system atrophy (MSA), hereditary ataxias, Huntington's disease (HD), progressive supranuclear palsy (PSP), and dementia with Lewy bodies (DLB). This article reviews the prevalence and characteristics of sleep disorders in these conditions, highlighting their impact on patients' quality of life and disease progression. Sleep-related breathing disorders, insomnia, restless legs syndrome (RLS), periodic limb movement syndrome (PLMS), and rapid eye movement sleep behavior disorder (RBD) are among the common sleep disturbances reported. Both pharmacological and non-pharmacological interventions play crucial roles in managing sleep disturbances and enhancing overall patient care.

Association of Night Shifts and Lifestyle Risks With Incident Dementia

BACKGROUND

Little is known about the combined relationship between night shifts and lifestyle risks with incident dementia or their potential interactions. To evaluate the association of night shifts and lifestyle risks with incident dementia and further analyze their interactions.

METHODS

A total of 276 059 participants were included in this study from the UK Biobank cohort. Cox proportional hazards models were used to investigate the combined association of night shifts and lifestyle risks with incident dementia.

RESULTS

Participants with always night shifts and 3 or 4 unhealthy lifestyle factors had the highest risk of incident all-cause dementia (hazard ratio: 3.15, 95% confidence interval [CI]: 1.74-5.69). An additive interaction was found between night shifts and lifestyle risks for incident all-cause dementia (p < .001), with a relative excess risk due to the interaction of 0.14 (95% CI: 0.11-0.45). The attributable proportions of the combined effect on the incidence of all-cause dementia were 22.6% (95% CI: 20.91%-26.75%) for night shift work, 65.0% (95% CI: 63.12%-69.80%) for unhealthy lifestyle factors, and 12.1% (95% CI: 8.67%-18.04%) for their interaction.

CONCLUSIONS

Both night shifts and lifestyle risks were associated with a higher risk of incident dementia. The combined impact was higher than the increase in the risks related to each single factor. Our results indicated that most incident dementia cases might be prevented by a healthy lifestyle, and the benefits would be greater among night shift workers. Further studies are needed to confirm our results and explore the underlying mechanisms.

A high propensity for excessive daytime sleepiness independent of lifestyle is associated with cognitive performance in community-dwelling older adults

Objective

The relationship between excessive daytime sleepiness (EDS) and cognitive performance of older adults remains unclear, especially when a healthy lifestyle is considered. The study aimed to explore the association between EDS in passive and active situations and general cognitive function among community-dwelling older adults.

Methods

Two hundred and seventy-one older adults aged 60 and above were recruited from the community cohort in Shangrao. All study participants were free of depression and dementia. The Chinese version of the Epworth Sleepiness Scale (CESS) was used to evaluate EDS. Using the item scores of CESS, the presence of EDS among all study participants were grouped as non-EDS, passive situation-related EDS (PSR-EDS), active situation-related EDS (ASR-EDS), and high sleep propensity (HSP). The Hong Kong Brief Cognitive Test (HKBC) was used to assess cognitive function. Chinese healthy lifestyle metrics were scored based on AHA Life Simple-7. The multivariate logistic regression model was used to estimate the association between the presence of EDS and cognitive function.

Results

The PSR-EDS (n = 29, 20.8 ± 5.3) and the HSP groups (n = 21, 19.8 ± 4.8) scored lower with HKBC than in the non-EDS group (n = 213, 23.2 ± 4.9). The subdomain performance of language in the HSP group was poorer than in the non-EDS group (ps < 0.05). Relative to non-EDS, HSP (OR = 3.848, 95% CI = 1.398-10.591) was associated with an increased risk of poor cognitive performance after adjusting age, sex, education, and healthy lifestyle metrics.

Conclusion

High propensity for excessive daytime sleepiness, irrespective of lifestyle, is associated with poorer cognitive performance among community-dwelling older adults. The findings may provide empirical evidence to support sleepiness intervention for reducing the risk of cognitive decline.

Association of sleep disorders with clinical symptoms and age in Chinese older adult patients with and without cognitive decline

Objective

To investigate correlation between cognitive function, age, and sleep disturbances.

Methods

This retrospective clinical study enrolled 78 patients with sleep disorders who were divided into three groups: a group of 24 patients with sleep disorders accompanied by cognitive decline (SD-CD); 54 patients with sleep disorders and no cognitive decline (SD-nCD) was divided into two groups, one of 30 patients aged between 60 and 70 years and another of 24 patients aged >70 years. Polysomnography was used to record patients' sleep indicators throughout night; these included total sleep duration, sleep efficiency (SE), sleep latency, sleep structure and percentage of N1, N2, and N3 stages, rapid eye movement (REM) stage, as well as apnea hypopnea index (AHI), and oxygen saturation (OS). Analysis of variance (ANOVA) for continuous variables and chi-square test for categorical variables were used to analyze variables between different groups. Pearson's correlation was used to analyze correlation between sleep parameters and mini-mental state examination (MMSE). Blood samples were used to determine their Aβ, Aβ40, Aβ42, total tau, phosphorylated tau protein (ptau), ptau181, ptau217, the inflammatory factor IL-1β, vitamin B12 (VB12), and melatonin levels.

Results

In the SD-CD group, there was a significant decrease in SE and an increase in N1 stage sleep in older patients and a significant increase in AHI, REM stage AHI, and non-REM stage AHI. In patients with SD-nCD, the minimum OS, minimum OS in the REM period, and minimum OS in the non-REM period were significantly reduced. OS was significantly correlated with cognitive level, as evaluated by the MMSE. The addition of sleep parameters can significantly improve the accuracy of dementia diagnosis. Dementia biomarkers of Aβ and tau proteins in blood showed cognition-related differences, while ptau181 was associated with both cognition and age-related differences. Regression models revealed that age was related to higher levels of cognitive decline before (β = -0.43, P < 0.001) and after (β = -0.38, P < 0.001) adjustment of gender, BMI, and education level. There was a significant mediation effect of relationship between aging and cognitive function by sleep efficiency and N1 stage sleep.

Conclusion

Sleep disorders and low OS are associated with a higher incidence of cognitive decline and dementia.

Therapeutic dilemma's: antipsychotics use for neuropsychiatric symptoms of dementia, delirium and insomnia and risk of falling in older adults, a clinical review

PURPOSE

Because of the common and increasing use of antipsychotics in older adults, we aim to summarize the current knowledge on the causes of antipsychotic-related risk of falls in older adults. We also aim to provide information on the use of antipsychotics in dementia, delirium and insomnia, their adverse effects and an overview of the pharmacokinetic and pharmacodynamic mechanisms associated with antipsychotic use and falls. Finally, we aim to provide information to clinicians for weighing the benefits and harms of (de)prescribing.

METHODS

A literature search was executed in CINAHL, PubMed and Scopus in March 2022 to identify studies focusing on fall-related adverse effects of the antipsychotic use in older adults. We focused on the antipsychotic use for neuropsychiatric symptoms of dementia, insomnia, and delirium.

RESULTS

Antipsychotics increase the risk of falls through anticholinergic, orthostatic and extrapyramidal effects, sedation, and adverse effects on cardio- and cerebrovascular system. Practical resources and algorithms are available that guide and assist clinicians in deprescribing antipsychotics without current indication.

CONCLUSIONS

Deprescribing of antipsychotics should be considered and encouraged in older people at risk of falling, especially when prescribed for neuropsychiatric symptoms of dementia, delirium or insomnia. If antipsychotics are still needed, we recommend that the benefits and harms of antipsychotic use should be reassessed within two to four weeks of prescription. If the use of antipsychotic causes more harm than benefit, the deprescribing process should be started.

APOE-ε4 synergizes with sleep disruption to accelerate Aβ deposition and Aβ-associated tau seeding and spreading

Alzheimer's disease (AD) is the most common cause of dementia. The APOE-ε4 allele of the apolipoprotein E (APOE) gene is the strongest genetic risk factor for late-onset AD. The APOE genotype modulates the effect of sleep disruption on AD risk, suggesting a possible link between apoE and sleep in AD pathogenesis, which is relatively unexplored. We hypothesized that apoE modifies Aβ deposition and Aβ plaque-associated tau seeding and spreading in the form of neuritic plaque-tau (NP-tau) pathology in response to chronic sleep deprivation (SD) in an apoE isoform-dependent fashion. To test this hypothesis, we used APPPS1 mice expressing human APOE-ε3 or -ε4 with or without AD-tau injection. We found that SD in APPPS1 mice significantly increased Aβ deposition and peri-plaque NP-tau pathology in the presence of APOE4 but not APOE3. SD in APPPS1 mice significantly decreased microglial clustering around plaques and aquaporin-4 (AQP4) polarization around blood vessels in the presence of APOE4 but not APOE3. We also found that sleep-deprived APPPS1:E4 mice injected with AD-tau had significantly altered sleep behaviors compared with APPPS1:E3 mice. These findings suggest that the APOE-ε4 genotype is a critical modifier in the development of AD pathology in response to SD.

Decoding information about cognitive health from the brainwaves of sleep

Sleep electroencephalogram (EEG) signals likely encode brain health information that may identify individuals at high risk for age-related brain diseases. Here, we evaluate the correlation of a previously proposed brain age biomarker, the "brain age index" (BAI), with cognitive test scores and use machine learning to develop and validate a series of new sleep EEG-based indices, termed "sleep cognitive indices" (SCIs), that are directly optimized to correlate with specific cognitive scores. Three overarching cognitive processes were examined: total, fluid (a measure of cognitive processes involved in reasoning-based problem solving and susceptible to aging and neuropathology), and crystallized cognition (a measure of cognitive processes involved in applying acquired knowledge toward problem-solving). We show that SCI decoded information about total cognition (Pearson's r = 0.37) and fluid cognition (Pearson's r = 0.56), while BAI correlated only with crystallized cognition (Pearson's r = - 0.25). Overall, these sleep EEG-derived biomarkers may provide accessible and clinically meaningful indicators of neurocognitive health.

Gender differences in cognitive function and its associated factors among older adults with type 2 diabetes

Diabetes is widely prevalent among older people and can influence accelerated cognitive decline. Gender-based disparities may contribute to variations in cognitive decline. This study examined gender differences in cognitive function and associated factors among older adults with diabetes. A cross-sectional study was conducted involving 318 Taiwanese older adults with type 2 diabetes. Demographic, health, and diabetes-related data were collected, and cognitive neuropsychological tests were evaluated. Compared to men, women with diabetes showed significantly poorer performance in global cognitive function and executive function. Age, years of education, sleep quality, and HbA1c were correlated with domains of cognitive function in men, whereas age, years of education, depressive symptoms, HbA1c, and duration of diabetes were associated with domains of cognitive function among women. Nurses should recognize gender differences in factors associated with cognitive function in older adults with diabetes and should develop individualized interventions to improve patients' cognitive function.

Dementia Scale Classification with Sequential Model from Sleep Activity Data

Dementia, a disorder caused by brain diseases, has been found to influence the sleep patterns of patients. The finding indicates that monitoring sleep activity is helpful to detect the change in cognitive status. With this in mind, the aim of this study is to explore the possibility to develop a machine learning model for classifying the scores of dementia screening tests based on sleep activity data which could be recorded with less burden for participants. In this study, We collected sleep activity data from 124 elderly patients with varying cognitive states, including heart rate, respiratory rate and depth of sleep, using a single sensor. The score of Mini Mental State Estimation (MMSE) cognitive test is used to determine the level of cognitive states. First, we conducted a statistical analysis of the measured sleep activity data to find specific features observed in people with low-MMSE scores. Second, we utilized an efficient sequence model for capturing time-series changes in sleep activity for binary classification of the dementia scale to detect such low-MMSE people. Our findings revealed significant distinctions in sleep patterns between high and low cognitive status groups, and in the classification task, a maximum macro F1 score of 0.67 was achieved using LSTM models. Our results suggest the validity of using sleep activity data for the prediction of dementia classification.

Sleep Problems Associate With Multimorbidity: A Systematic Review and Meta-analysis

Objectives: To summarize the evidence on the association between sleep problems and multimorbidity. Methods: Six electronic databases (PubMed, Web of Science, Embase, China National Knowledge Infrastructure, VIP, and Wan fang) were searched to identify observational studies on the association between sleep problems and multimorbidity. A random-effects model was used to estimate the pooled odds ratios (ORs) and 95% confidence intervals for multimorbidity. Results: A total of 17 observational studies of 133,575 participants were included. Sleep problems included abnormal sleep duration, insomnia, snoring, poor sleep quality, obstructive sleep apnea (OSA) and restless legs syndrome (RLS). The pooled ORs (95% CIs) for multimorbidity were 1.49 (1.24-1.80) of short sleep duration, 1.21 (1.11-1.44) of long sleep duration and 2.53 (1.85-3.46) for insomnia. The association of other sleep problems with multimorbidity was narratively summarized due to limited number of comparable studies. Conclusion: Abnormal sleep duration and insomnia are associated with higher odds of multimorbidity, while the evidence on association of snoring, poor sleep quality, obstructive sleep apnea and restless legs syndrome with multimorbidity remains inconclusive. Interventions targeting sleep problems should be delivered for better management of multimorbidity.

Sleep Signal Analysis for Early Detection of Alzheimer's Disease and Related Dementia (ADRD)

OBJECTIVE

Alzheimer's Disease and Related Dementia (ADRD) is growing at alarming rates, putting research and development of diagnostic methods at the forefront of the biomedical research community. Sleep disorder has been proposed as an early sign of Mild Cognitive Impairment (MCI) in Alzheimer's disease. Although several clinical studies have been conducted to assess sleep and association with early MCI, reliable and efficient algorithms to detect MCI in home-based sleep studies are needed in order to address both healthcare costs and patient discomfort in hospital/lab-based sleep studies.

METHODS

In this paper, an innovative MCI detection method is proposed using an overnight recording of movements associated with sleep combined with advanced signal processing and artificial intelligence. A new diagnostic parameter is introduced which is extracted from the correlation between high frequency, sleep-related movements and respiratory changes during sleep. The newly defined parameter, Time-Lag (TL), is proposed as a distinguishing criterion that indicates movement stimulation of brainstem respiratory regulation that may modulate hypoxemia risk during sleep and serve as an effective parameter for early detection of MCI in ADRD. By implementing Neural Networks (NN) and Kernel algorithms with choosing TL as the principle component in MCI detection, high sensitivity (86.75% for NN and 65% for Kernel method), specificity (89.25% and 100%), and accuracy (88% and 82.5%) have been achieved.

Sleep movements and respiratory coupling as a biobehavioral metric for early Alzheimer's disease in independently dwelling adults

INTRODUCTION

Sleep disorder is often the first symptom of age-related cognitive decline associated with Alzheimer's disease (AD) observed in primary care. The relationship between sleep and early AD was examined using a patented sleep mattress designed to record respiration and high frequency movement arousals. A machine learning algorithm was developed to classify sleep features associated with early AD.

METHOD

Community-dwelling older adults (N = 95; 62-90 years) were recruited in a 3-h catchment area. Study participants were tested on the mattress device in the home bed for 2 days, wore a wrist actigraph for 7 days, and provided sleep diary and sleep disorder self-reports during the 1-week study period. Neurocognitive testing was completed in the home within 30-days of the sleep study. Participant performance on executive and memory tasks, health history and demographics were reviewed by a geriatric clinical team yielding Normal Cognition (n = 45) and amnestic MCI-Consensus (n = 33) groups. A diagnosed MCI group (n = 17) was recruited from a hospital memory clinic following diagnostic series of neuroimaging biomarker assessment and cognitive criteria for AD.

RESULTS

In cohort analyses, sleep fragmentation and wake after sleep onset duration predicted poorer executive function, particularly memory performance. Group analyses showed increased sleep fragmentation and total sleep time in the diagnosed MCI group compared to the Normal Cognition group. Machine learning algorithm showed that the time latency between movement arousals and coupled respiratory upregulation could be used as a classifier of diagnosed MCI vs. Normal Cognition cases. ROC diagnostics identified MCI with 87% sensitivity; 89% specificity; and 88% positive predictive value.

DISCUSSION

AD sleep phenotype was detected with a novel sleep biometric, time latency, associated with the tight gap between sleep movements and respiratory coupling, which is proposed as a corollary of sleep quality/loss that affects the autonomic regulation of respiration during sleep. Diagnosed MCI was associated with sleep fragmentation and arousal intrusion.

Mediterranean diet, mental health, cognitive status, quality of life, and successful aging in southern Italian older adults

Healthy successful aging with preserved mental and cognitive health is expected to be one of the most important challenges of the growing old population globally. Studies investigating these multi-dimensional aspects of senescence are important to identify potential targets for early prevention. The aim of this study was to investigate the relation between adherence to the Mediterranean diet and mental and cognitive health, quality of life, and successful aging in middle-age and older adults living in Sicily, southern Italy. Data from a sample of 883 individuals was collected including information on food intake (through a 110-item food frequency questionnaire), sleep quality (through the Pittsburgh sleep quality index) depressive symptoms (through the Center for the Epidemiological Studies of Depression Short Form), quality of life (through the Manchester Short Assessment of Quality of Life), cognitive status (through the Short Portable Mental Status Questionnaire), and overall successful aging (through the Successful Aging Index). Multivariate logistic regression analyses were conducted to assess the association between adherence to the Mediterranean diet and the outcomes investigated. After adjustment for potential confounding factors, individuals in the highest quartile of adherence to the Mediterranean diet were less likely to have cognitive impairment (OR = 0.19, 95 % CI: 0.04, 0.86), depressive symptoms (OR = 0.19, 95 % CI: 0.08, 0.46) and more likely to have good quality of life (OR = 14.04, 95 % CI: 6.81, 28.93); significant results were also found for individuals in the third quartile of Mediterranean diet adherence and good sleep quality (OR = 1.65, 95 % CI: 1.03, 2.64). Moreover, individuals in the highest quartile of adherence were more likely to have a successful aging (OR = 1.65, 95 % CI: 1.01, 2.68). In conclusion, this study supports the hypothesis that adherence to the Mediterranean diet provides a positive trajectory toward a healthy successful aging, with major potential benefits toward mental and cognitive health.

Effectiveness of non-pharmacological interventions for sleep disturbances in people living with dementia: A systematic review and meta-analysis

We summarize the evidence on non-pharmacological interventions for sleep disturbances in people living with dementia(PlwD). A literature search was performed using PubMed, Embase, Cochrane library, Web of Science, PsycINFO, CINAHL, and clinicaltrials.gov. Up to August 20, 2022. Six studies met our eligibility criteria. Light therapy, the therapeutic pet-type robotic seal(PRAO), and slow-stroke back massage(SSBM) are non-pharmacological interventions for sleep disturbances in PlwD.PARO increased night-time sleep duration (p < 0.05). The benefit of SSBM for sleep disturbances in PlwD is unclear (p > 0.05). Although there is a lack of evidence for the effect of light therapy on sleep disturbances in PlwD (p > 0.05), light therapy reduced sleep disturbance (SMD = -0.38; 95% CI:1.25, 0.48), increased sleep efficiency (MD = 3.77; 95% CI:-0.23, 7.78), and also reduced depression (MD = -2.49; 95% CI: -2.92, -2.06). More large-scale randomized controlled trials are needed and consider combining multiple non-pharmacological measures for sleep interventions in PlwD.

Mental and physical health pathways linking insomnia symptoms to cognitive performance 14 years later

STUDY OBJECTIVES

Insomnia may be a modifiable risk factor for later-life cognitive impairment. We investigated: (1) which insomnia symptoms are associated with subsequent cognitive functioning across domains; (2) whether insomnia-cognition associations are mediated by mental and physical health; and (3) whether these associations are modified by gender.

METHODS

Participants included 2595 adults ages 51-88 at baseline (Mage=64.00 ± 6.66, 64.5% women) in the Health and Retirement Study. The frequency of insomnia symptoms (difficulty initiating sleep, night time awakenings, early awakenings, and feeling unrested upon awakening) at baseline (2002) were quantified using a modified Jenkins Sleep Questionnaire. Cognition was assessed in 2016 via the Harmonized Cognitive Assessment Protocol and operationalized with factor scores corresponding to five domains. Depressive symptoms and vascular conditions in 2014 were assessed via self-report. Structural equation models estimated total, indirect, and direct effects of insomnia symptoms on subsequent cognition through depressive symptoms and vascular diseases, controlling for baseline sociodemographic and global cognition.

RESULTS

Frequent difficulty initiating sleep was associated with poorer episodic memory, executive function, language, visuoconstruction, and processing speed 14 years later (-0.06 ≤ β ≤ -0.04; equivalent to 2.2-3.4 years of aging). Depressive symptoms explained 12.3%-19.5% of these associations and vascular disease explained 6.3%-14.6% of non-memory associations. No other insomnia symptoms were associated with cognition, and no associations were modified by gender.

CONCLUSIONS

Difficulty initiating sleep in later life may predict future cognitive impairment through multiple pathways. Future research with longitudinal assessments of insomnia, insomnia treatments, and cognition is needed to evaluate insomnia as a potential intervention target to optimize cognitive aging.

Prevalence of sleep-related breathing disorders and associated risk factors among people with dementia: A meta-analysis

OBJECTIVE

Sleep-related breathing disorders (SRBD) have shown to cause worsened cognitive impairment among people with dementia. Therefore, we conducted the first meta-analysis to estimate the prevalence of SRBD among people with dementia.

METHODS

Comprehensive searches were conducted in Embase, Ovid-MEDLINE, PubMed, PsycINFO, Scopus, Web of Science, and CINAHL. The generalized linear mixed model (GLMM) was used for the pooled prevalence analysis and heterogeneity using I² test and Cochran's Q-statistic in R-software. Study quality was assessed by Hoy's risk of bias assessment tool. Overall, 20 studies from 1282 studies were included with 1461 participants.

RESULTS

The pooled prevalence of SRBD among dementia was 59% (95%CI: 44%-73%) with 55% (95%CI: 34%-74%) for obstructive sleep apnea (OSA), 49% (95%CI: 25%-73%) for unspecified SRBD, and 11% (95%CI: 5%-21%) for central sleep apnea (CSA). Regarding dementia subtypes, the prevalence of SRBD was 89% (95%CI: 61%-97%) for Alzheimer's dementia, 56% (95%CI: 48%-63%) for Parkinson's and Idiopathic Parkinson's dementia, and 16% (95%CI: 8%-30%) for Huntington's dementia. Significant moderator variables were male, body mass index, larger waist and hip circumference, waist-hip ratio, and comorbidities including hypertension, dyslipidemia, renal disease, diabetes, heart disease, and stroke.

CONCLUSIONS

There is considerable high prevalence of SRBD among dementia people, with OSA and unspecified SRBD being fivefold higher than CSA. Regarding dementia subtypes, Parkinson's and Idiopathic Parkinson's, and Alzheimer's dementia had four to sixfold increased risk of presenting with SRBD than Huntington's dementia. Therefore, assessment and management of SRBD in Alzheimer's, and Parkinson's and Idiopathic Parkinson's dementia deserves more attention in future research.