The effect of insomnia on development of Alzheimer's disease

Alzheimer's disease and insomnia: a bibliometric study and visualization analysis

Background

Alzheimer's disease (AD) is the fastest-growing neurodegenerative disorder globally, with patient numbers expected to rise to 130 million by 2050. Insomnia, a prevalent comorbidity, exhibits a bidirectional relationship with AD: insomnia accelerates AD pathology, while AD worsens sleep disorders. This relationship has emerged as a key area of research. Current mechanisms involve oxidative stress, inflammatory responses, and glymphatic system dysfunction, yet a comprehensive review of these processes remains absent.

Objective

To conduct a visual analysis of the relationship between Alzheimer's disease and insomnia using CiteSpace.

Methods

Literature on "insomnia" and "Alzheimer's disease" published between January 1, 2000, and October 31, 2024, was retrieved from the Web of Science Core Collection. CiteSpace and VOSviewer software were used to analyze institutions, authors, and keywords.

Results

A total of 1,907 articles were analyzed, revealing a consistent upward trend in publication volume. The United States and the Mayo Clinic were identified as leading contributors, producing 704 and 57 publications, respectively. Boeve Bradley F the most prolific author contributed 30 publications. Collaboration was actively observed among countries, institutions, and authors. High-frequency keywords identified were "Parkinson's disease," "cognitive impairment," and "sleep behavior disorder." Emerging research areas are likely to focus on "sleep quality" and the "glymphatic system."

Conclusion

This study is the first to apply bibliometric analysis to identify three key trends in AD and insomnia research: the dominance of the United States and Mayo Clinic, strong international collaboration, and a focus on critical areas such as cognitive impairment, the glymphatic system, and sleep interventions. Insomnia may accelerate AD progression via multiple pathways, indicating that enhancing sleep quality could provide new strategies for early intervention. Future research should prioritize advancing the clinical translation of sleep interventions and investigating the mechanisms of the glymphatic system.

Impact of insomnia: Cultural and societal aspects from a European survey

OBJECTIVES

This European study explored the cultural and societal aspects of chronic insomnia by means of a survey undertaken in France, Germany, Italy, Spain, and the United Kingdom. The primary objectives were to understand the impact of insomnia on the daily lives of patients, both personally and professionally, and to evaluate the patients' perceptions and coping strategies thus identifying cultural differences in the management of this disorder.

METHODS

Based on online panels targeting insomnia sufferers, the survey included 755 patients aged 35 to 65 years with moderate to severe insomnia for at least three months, occurring at least three times per week (DSM-5 criteria for insomnia disorder, ISI score 15-28). Topics covered included the impact of insomnia on daily life, strategies for coping and managing insomnia, and patients' perceptions and views of insomnia.

RESULTS

A total of 755 patients completed the questionnaire. Most respondents were women (70%) and between 35 and 49 years of age (50%). About half of the patients (49%) had severe insomnia, with 49% experiencing it for over three years. Nearly 70% did not initially consider their insomnia serious, and 73% believed their condition would improve over time. Stress (39%), difficulty relaxing in the evening (37%), and a rapid flow of thoughts (37%) were identified as the main causes of insomnia. Insomnia was shown to significantly affect daily life, particularly work performance, relationships, and maintaining healthy habits. British patients were the most affected, with 85% reporting decreased work performance. In France, only 51% reported difficulties maintaining relationships. There were 77% of Britons who felt exposed to dangerous situations, such as drowsiness while driving (47%). Coping strategies varied by country but, overall, breathing exercises (43%), meditation (32%), and reducing caffeine intake (44%) were the most popular. Healthcare consultation approaches also varied. French patients consulted general practitioners (89%) but rarely specialists, while Germans consulted sleep specialists (20%) and psychiatrists (19%). Overall, 61% reported that doctors recommended lifestyle changes.

CONCLUSIONS

The survey highlights cultural differences in insomnia perception and management in Europe. Insomnia is often trivialized, thus delaying management. The results underline the need to raise awareness among patients and healthcare professionals of the importance of insomnia and its consequences on mental and physical health. Addressing chronic insomnia requires a multifaceted approach that includes cultural sensitivity, patient education, and proactive healthcare engagement. By understanding and integrating these elements, healthcare providers can better support patients to manage their condition, ultimately improving their quality of life.

Mapping the Neural Basis of Wake Onset Regularity and Its Effects on Sleep Quality and Positive Affect

The regularity of sleep-wake cycles is a defining characteristic of normative sleep patterns that are typically associated with proper circadian rhythmicity. The previous literature indicates that consistent patterns of sleep and wake are associated with improved sleep quality and cognitive functioning. Conversely, sleep irregularity has been associated with reduced well-being and inefficiency in resting-state neural networks. This study investigated the relationship between specific sleep regularity measures and outcomes, including emotional affect, sleep quality, and resting-state functional connectivity. We found that variability in wake onset predicted poorer sleep quality and reduced positive affect. Furthermore, sleep regularity measures were associated with altered functional connectivity between the posterior cingulate cortex and regions involved in emotional processing. We propose that alterations in default mode network (DMN) connectivity linked to sleep irregularity reflect disruptions in emotional processing and sleep quality.

Imbalanced sleep increases mortality risk by 14-34%: a meta-analysis

Sleep duration is a crucial factor influencing health outcomes, yet its relationship with mortality remains debated. In this meta-analysis, we aimed to investigate the association between short and long sleep duration and all-cause mortality in adults, including sex-specific differences. A systematic search was performed in multiple databases, including PubMed, Cochrane Central, and Web of Science, up to October 2024. Retrospective and prospective cohort studies involving adults with at least 1 year of follow-up and data on sleep duration and all-cause mortality were included. Hazard ratios were pooled using a random-effects model, with subgroup analyses performed based on sex and sleep duration categories. A total of 79 cohort studies were included, with data stratified by sex and categorized into short and long sleep durations. Short sleep duration (< 7 h per night) was associated with a 14% increase in mortality risk compared to the reference of 7-8 h, with a pooled hazard ratio of 1.14 (95% CI 1.10 to 1.18). Conversely, long sleep duration (≥ 9 h per night) was associated with a 34% higher risk of mortality, with a hazard ratio of 1.34 (95% CI 1.26 to 1.42). Sex-specific analyses indicated that both short and long sleep durations significantly elevated mortality risk in men and women, although the effect was more pronounced for long sleep duration in women. Both short and long sleep durations are associated with increased all-cause mortality, though the degree of risk varies by sex. These findings underscore the importance of considering optimal sleep duration in public health strategies aimed at enhancing longevity and highlight the need for sex-specific approaches in sleep health research.

Role of OX/OXR cascade in insomnia and sleep deprivation link Alzheimer's disease and Parkinson's disease: Therapeutic avenue of Dual OXR Antagonist (DORA)

Sleep plays a role in the elimination of neurotoxic metabolites that are accumulated in the waking brain as a result of neuronal activity. Long-term insomnia and sleep deprivation are associated with oxidative stress, neuroinflammation, amyloid beta (Aβ) deposition, and Lewy body formation, which are known to increase the risk of mild cognitive impairment (MCI) and dementia. Orexin A (OXA) and orexin B (OXB), two neuropeptides produced in the lateral hypothalamus, are known to influence the sleep-wake cycle and the stress responses through their interactions with OX receptor 1 (OX1R) and OX receptor 2 (OX2R), respectively. OX/OXR cascade demonstrates intricate neuroprotective and anti-inflammatory effects by inhibiting nuclear factor-kappa B (NF-kB) and PLC/Ca2+ pathway activation. OX1R binds OXA more strongly than OXB by one-order ratio, whereas OX2R binds both OXA and OXB with equal strengths. Overexpression of OXs in individuals experiences sleep deprivation, circadian rhythm disturbances, insomnia-associated MCI, Parkinson's disease (PD), and Alzheimer's disease (AD). Many dual OXR antagonists (DORAs) have been effective in their clinical studies, with suvorexant and daridorexant receiving FDA clearance for insomnia therapy in 2014 and 2022 respectively. The results of clinical studies suggested that there is a new pharmaceutical option for treating insomnia and the sleep deprivation-AD/PD relationship by targeting the OXR system. DORAs treatment reduces Aβ deposition in the brain and improves synaptic plasticity and circadian expression. This review indicates the link between sleep disorders and MCI, DORAs are an appropriate medication category for treating insomnia, and sleep deprivation links AD and PD.

The role of sleep in Alzheimer's disease: a mini review

Sleep is a stereotyped and well-preserved series of neurophysiological states that are essential for overall health and brain functioning. Emerging research suggests that sleep disturbances are not only associated with but also causally contribute to neurodegenerative disease onset and progression. This mini-review examines some of the current knowledge and evidence for relationships between sleep abnormalities and Alzheimer's disease within context of possible uses and limitations of sleep biomarkers for evaluation of Alzheimer's disease. Understanding these relationships could lead to readily accessible and easily quantifiable biomarkers of Alzheimer's dementia.

Diffusion Tensor Imaging Analysis Along the Perivascular Space (DTI-ALPS) Demonstrates That Sleep Disorders Exacerbate Glymphatic Circulatory Impairment and Cognitive Impairment in Patients with Alzheimer's Disease

Objective

Sleep disorders are common in Alzheimer's disease (AD) patients and can impair the glymphatic system, leading to cognitive decline. This study aimed to investigate whether AD patients with sleep disorders exhibit worse glymphatic function and more severe cognitive impairment compared to those without sleep disorders and to explore the underlying molecular imaging mechanisms.

Methods

This study included 40 AD patients with sleep disorders (ADSD), 39 cognitively matched AD patients without sleep disorders (ADNSD), and 25 healthy middle-aged and elderly controls (NC). Participants underwent functional magnetic resonance imaging (fMRI), and cognitive and sleep assessments. The ALPS (Along the Perivascular Space) index was calculated, followed by intergroup comparisons, correlation analyses, and mediation analyses. The diagnostic utility of the ALPS index was assessed using a receiver operating characteristic (ROC) curve.

Results

The ALPS index was lower in the ADNSD and ADSD groups compared to the NC group. In the ADSD group, PSQI scores were negatively correlated with MMSE scores. The ALPS index was positively correlated with MMSE scores and negatively with PSQI scores. Mediation analyses indicated that the ALPS index partially mediated the effect of sleep disturbances on cognitive impairment (indirect effect = -0.134; mediation effect = 30.505%). The area under the ROC curve (AUROC) for distinguishing ADSD from ADNSD was 0.86, with a cutoff ALPS index value 1.309.

Conclusion

Sleep disorders worsen glymphatic function and cognitive impairment in AD patients. The ALPS index partially mediates the impact of sleep disorders on cognitive function and shows moderate accuracy in distinguishing between patients with ADSD and ADNSD.

Prolonged nightly fasting in older adults with memory decline: A single-group pilot study exploring changes in cognitive function and cardiometabolic risk factors

Introduction

Older age significantly increases risk for cognitive decline. A growing number of older adults (≥ 65 years) experience cognitive decline that compromises immediate and/or long-term health. Interventions to mitigate cognitive decline are greatly needed. Intermittent fasting aligned with innate circadian rhythms is associated with health benefits and improved circadian rhythms; here, we explore impacts on cognition and cardiometabolic outcomes.

Methods

We conducted a single-group, pre-/post-pilot study to explore an 8-week prolonged nightly fasting intervention (14 h fasting/night) among adults 65+ years with self-reported memory decline. We explored changes in cognitive function, insomnia, and cardiometabolic risk factors. Intervention engagement/adherence were assessed. The intervention was delivered fully remotely; participants completed their fasting protocol at home and were not required to come into the lab.

Results

In total, 20 individuals signed consent and 18 participants completed the study. Participants were mean age 69.7 years, non-Hispanic White (89%), predominantly female (95%), married (50%), and employed (65%). Paired t-tests indicated an increase in cognitive function (Memory and Attention Phone Screener) (p = 0.02) with a medium effect size (Cohen's d = 0.58) and a decrease in insomnia (Insomnia Severity Index) (p = 0.04) with a medium effect size (Cohen's d = 0.52). Changes in BMI or diet quality were not observed. Engagement (66%-77%) and adherence (70%-100%) were high.

Conclusion

These pilot findings suggest that prolonged nightly fasting, targeted to align food intake with circadian rhythms, may improve cognitive function and sleep among older adults. Fully powered, randomized controlled trials to test the efficacy of this non-pharmacological, low cost-to-burden ratio intervention are needed.

Alpha rhythm slowing in temporal lobe epilepsy across scalp EEG and MEG

EEG slowing is reported in various neurological disorders including Alzheimer's, Parkinson's and Epilepsy. Here, we investigate alpha rhythm slowing in individuals with refractory temporal lobe epilepsy compared with healthy controls, using scalp EEG and magnetoencephalography. We retrospectively analysed data from 17 (46) healthy controls and 22 (24) individuals with temporal lobe epilepsy who underwent scalp EEG and magnetoencephalography recordings as part of presurgical evaluation. Resting-state, eyes-closed recordings were source reconstructed using the standardized low-resolution brain electrographic tomography method. We extracted slow 6-9 Hz and fast 10-11 Hz alpha relative band power and calculated the alpha power ratio by dividing slow alpha by fast alpha. This ratio was computed for all brain regions in all individuals. Alpha oscillations were slower in individuals with temporal lobe epilepsy than controls (P< 0.05). This effect was present in both the ipsilateral and contralateral hemispheres and across widespread brain regions. Alpha slowing in temporal lobe epilepsy was found in both EEG and magnetoencephalography recordings. We interpret greater slow alpha as greater deviation from health.

Sleep disorders and risk of alzheimer's disease: A two-way road

Substantial sleep impairment in patients with Alzheimer's disease (AD) is one of the emerging points for continued efforts to better understand the disease. Individuals without cognitive decline, an important marker of the clinical phase of AD, may show early alterations in the sleep-wake cycle. The objective of this critical narrative review is to explore the bidirectional pathophysiological correlation between sleep disturbances and Alzheimer's Disease. Specifically, it examines how the disruption of sleep homeostasis in individuals without dementia could contribute to the pathogenesis of AD, and conversely, how neurodegeneration in individuals with Alzheimer's Disease might lead to dysregulation of the sleep-wake cycle. Recent scientific results indicate that sleep disturbances, particularly those related to impaired glymphatic clearance, may act as an important mechanism associated with the genesis of Alzheimer's Disease. Additionally, amyloid deposition and tau protein hyperphosphorylation, along with astrocytic hyperactivation, appear to trigger changes in neurotransmission dynamics in areas related to sleep, which may explain the onset of sleep disturbances in individuals with AD. Disruption of sleep homeostasis appears to be a modifiable risk factor in Alzheimer's disease. Whenever possible, the use of non-pharmacological strategies becomes important in this context. From a different perspective, additional research is needed to understand and treat the dysfunction of the sleep-wake cycle in individuals already affected by AD. Early recognition and correction of sleep disturbances in this population could potentially mitigate the progression of dementia and improve the quality of life for those with AD.

The interplay between insomnia symptoms and Alzheimer's disease across three main brain networks

STUDY OBJECTIVES

Insomnia symptoms are prevalent along the trajectory of Alzheimer's disease (AD), but the neurobiological underpinning of their interaction is poorly understood. Here, we assessed structural and functional brain measures within and between the default mode network (DMN), salience network, and central executive network (CEN).

METHODS

We selected 320 participants from the ADNI database and divided them by their diagnosis: cognitively normal (CN), Mild Cognitive Impairment (MCI), and AD, with and without self-reported insomnia symptoms. We measured the gray matter volume (GMV), structural covariance (SC), degrees centrality (DC), and functional connectivity (FC), testing the effect and interaction of insomnia symptoms and diagnosis on each index. Subsequently, we performed a within-group linear regression across each network and ROI. Finally, we correlated observed abnormalities with changes in cognitive and affective scores.

RESULTS

Insomnia symptoms were associated with FC alterations across all groups. The AD group also demonstrated an interaction between insomnia and diagnosis. Within-group analyses revealed that in CN and MCI, insomnia symptoms were characterized by within-network hyperconnectivity, while in AD, within- and between-network hypoconnectivity was ubiquitous. SC and GMV alterations were nonsignificant in the presence of insomnia symptoms, and DC indices only showed network-level alterations in the CEN of AD individuals. Abnormal FC within and between DMN and CEN hubs was additionally associated with reduced cognitive function across all groups, and increased depressive symptoms in AD.

CONCLUSIONS

We conclude that patients with clinical AD present with a unique pattern of insomnia-related functional alterations, highlighting the profound interaction between both conditions.

Sedative-Hypnotic Effect and Mechanism of Carbon Nanofiber Loaded with Essential Oils of Ligusticum chuanxiong (Ligusticum chuanxiong Hort.) and Finger Citron (Citrus medica L. var. sarcodactylis) on Mice Models of Insomnia

(1) Background: Insomnia is a neurological illness that poses a significant threat to both physical and mental health. It results in the activation of neuroglial cells, heightened neuroinflammation, oxidative stress, and disruptions in the Hypothalamic-Pituitary-Adrenal (HPA) axis. Ligusticum Chuanxiong (CX) and Finger citron (FC) are frequently utilized botanicals for addressing sleeplessness. Both herbs possess notable anti-inflammatory properties in their volatile oils. However, their effectiveness is hindered by the nasal mucosal irritation and instability they exhibit. (2) Methods: This study involved the preparation of a nanofiber composite system using carbon nanofiber (CNF) suspensions containing essential oils of Ligusticum chuanxiong-Finger citron (CXEO-FCEO-CNF). The effects and mechanisms of these essential oils in improving insomnia were investigated using an insomnia mouse model after encapsulation. (3) Results: The CXEO-FCEO-CNF had an average particle size of 103.19 ± 1.64 nm. The encapsulation rates of essential oils of Ligusticum chuanxiong (CXEO) and essential oils of Finger citron (FCEO) were 44.50% and 46.15%, respectively. This resulted in a considerable improvement in the stability of the essential oils over a period of 30 days. The essential oils effectively decreased the irritation of the nasal mucosa following encapsulation. Furthermore, CXEO-FCEO-CNF enhanced voluntary activity and sleep in mice with insomnia, notably boosted the activity of superoxide dismutase (SOD), reduced the concentration of lipoxidized malondialdehyde (MDA), decreased the levels of hormones associated with the HPA axis, and regulated the levels of neurotransmitters, resulting in a beneficial therapeutic outcome. CXEO-FCEO-CNF contains a total of 23 active ingredients, such as alpha-Asarone, (E)-methyl isoeugenol, and Senkyunolide. These ingredients primarily work by modulating the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling system to decrease oxidative stress and inflammatory reactions. (4) Conclusions: This study presented initial evidence that the combination of CXEO and FCEO in nanofiber formulations effectively reduces the nasal mucosal irritation and instability of essential oils. Furthermore, it demonstrated the potential anti-neuroinflammatory and therapeutic effects of these formulations in treating insomnia. Overall, this study provides a theoretical foundation for developing new essential oil formulations derived from herbs.

Effects of early midlife ovarian removal on sleep: Polysomnography-measured cortical arousal, homeostatic drive, and spindle characteristics

Bilateral salpingo-oophorectomy (BSO; removal of ovaries and fallopian tubes) prior to age 48 is associated with elevated risk for both Alzheimer's disease (AD) and sleep disorders such as insomnia and sleep apnea. In early midlife, individuals with BSO show reduced hippocampal volume, function, and hippocampal-dependent verbal episodic memory performance associated with changes in sleep. It is unknown whether BSO affects fine-grained sleep measurements (sleep microarchitecture) and how these changes might relate to hippocampal-dependent memory. We recruited thirty-six early midlife participants with BSO. Seventeen of these participants were taking 17β-estradiol therapy (BSO+ET) and 19 had never taken ET (BSO). Twenty age-matched control participants with intact ovaries (AMC) were also included. Overnight at-home polysomnography recordings were collected, along with subjective sleep quality and hot flash frequency. Multivariate Partial Least Squares (PLS) analysis was used to assess how sleep varied between groups. Compared to AMC, BSO without ET was associated with significantly decreased time spent in non-rapid eye movement (NREM) stage 2 sleep as well as increased NREM stage 2 and 3 beta power, NREM stage 2 delta power, and spindle power and maximum amplitude. Increased spindle maximum amplitude was negatively correlated with verbal episodic memory performance. Decreased sleep latency, increased sleep efficiency, and increased time spent in rapid eye movement sleep were observed for BSO+ET. Findings suggest there is an association between ovarian hormone loss and sleep microarchitecture, which may contribute to poorer cognitive outcomes and be ameliorated by ET.

Enhanced cerebral blood flow similarity of the somatomotor network in chronic insomnia: Transcriptomic decoding, gut microbial signatures and phenotypic roles

Chronic insomnia (CI) is a complex disease involving multiple factors including genetics, gut microbiota, and brain structure and function. However, there lacks a unified framework to elucidate how these factors interact in CI. By combining data of clinical assessment, sleep behavior recording, cognitive test, multimodal MRI (structural, functional, and perfusion), gene, and gut microbiota, this study demonstrated that enhanced cerebral blood flow (CBF) similarities of the somatomotor network (SMN) acted as a key mediator to link multiple factors in CI. Specifically, we first demonstrated that only CBF but not morphological or functional networks exhibited alterations in patients with CI, characterized by increases within the SMN and between the SMN and higher-order associative networks. Moreover, these findings were highly reproducible and the CBF similarity method was test-retest reliable. Further, we showed that transcriptional profiles explained 60.4 % variance of the pattern of the increased CBF similarities with the most correlated genes enriched in regulation of cellular and protein localization and material transport, and gut microbiota explained 69.7 % inter-individual variance in the increased CBF similarities with the most contributions from Negativicutes and Lactobacillales. Finally, we found that the increased CBF similarities were correlated with clinical variables, accounted for sleep behaviors and cognitive deficits, and contributed the most to the patient-control classification (accuracy = 84.4 %). Altogether, our findings have important implications for understanding the neuropathology of CI and may inform ways of developing new therapeutic strategies for the disease.

Mental health problems raise the odds of cognitive impairment in COVID-19 survivors

Background

COVID-19 survivors around the globe are suffering from mental health issues. While mental health problems can be an early warning sign of dementia, they may also increase the chances of developing the disease. In this study, we examined the mental health of COVID-19 survivors and mapped its associations with cognitive and demographic variables.

Method

COVID-19 survivors listed in the databases of three tertiary care hospitals in Kolkata were contacted sequentially. 376 willing patients were interviewed over the telephone. 99 COVID-19 patients and 31 matched controls participated in the in-person interviews that were arranged for a more detailed investigation. The participants were administered standardized tests that are widely used for the assessment of cognitive functioning and mental health status.

Result

64.89% of COVID-19 survivors reported a deterioration in physical functioning. 44.95% reported a decline in mental health, whereas 41.49% reported a drop in cognitive performance. Detailed investigations revealed that they had an increased risk of having depression, anxiety, and poor sleep quality by 91%, 68%, and 140%, respectively. 6.1% of the patients had mild cognitive impairment, and 4% had dementia. COVID-19 patients who had depression and anxiety were 8.6 and 19.4 times more likely to have cognitive decline, respectively. Compared to the matched controls, COVID-19 patients had greater depression (p<.001), anxiety (p<.001), stress (p =.003), and insomnia (p <.001). They also scored significantly lower on Addenbrooke's Cognitive Examination-III (p =.009) and Picture Naming Test (p =.005) and took significantly longer to complete Trail Making Test-A (p =.002).

Conclusion

COVID-19 survivors in this study had major mental health issues even one year after contracting the virus. They had significant cognitive deficits that might progress into dementia. Strict monitoring and systematic treatment plans should be implemented as soon as possible.

The protective effect of biotin supplementation and swimming training on cognitive impairment and mental symptoms in a rat model of Alzheimer's disease: A behavioral, biochemical, and histological study

Vitamin B (Vit B) plays a regulatory role in cognitive memory and learning. We examined the biochemical and behavioral effects of biotin supplementation (BS) and swimming training (ST) on Alzheimer's disease (AD), the most common type of dementia, in male rats. Sixty rats were randomly assigned to six groups: control, sham (receiving phosphate-buffered saline), AD (receiving a single injection of Aβ into the lateral ventricle), ST (for 28 days and before Aβ injection), and BS (receiving BS through oral gavage for 28 days before Aβ injection). The treatments were continued until the end of the behavioral tests. Learning and memory functions were investigated through the Morris water maze (MWM) and depression and anxiety-like behaviors were tested by elevated plus-maze (EPM) and forced swimming tests. In addition, oxidative stress biomarkers, such as total thiol groups (TTG) and malondialdehyde (MDA) in serum were assessed and histological studies were performed using brain tissues. In the AD group, Aβ increased the distance traveled and escape latency in the MWM, but co-administration of BS and ST attenuated the results of the MWM, EPM, and FST tests. Furthermore, BS decreased the litigious biochemical effects of Aβ by enhancing the levels of TTG, in addition to reducing serum MDA levels. The use of BS as a potent antioxidant improved Aβ-induced memory impairment. It attenuated oxidative stress biomarkers in the brain (number of Aβ plaques) and serum of AD rats. We provide evidence for the use of BS in neurodegenerative disorders, such as AD, to elucidate the possible mechanisms.

Aging, sex, metabolic and life experience factors: Contributions to neuro-inflammaging in Alzheimer's disease research

Alzheimer's disease (AD) is prevalent around the world, yet our understanding of the disease is still very limited. Recent work suggests that the cornerstone of AD may include the inflammation that accompanies it. Failure of a normal pro-inflammatory immune response to resolve may lead to persistent central inflammation that contributes to unsuccessful clearance of amyloid-beta plaques as they form, neuronal death, and ultimately cognitive decline. Individual metabolic, and dietary (lipid) profiles can differentially regulate this inflammatory process with aging, obesity, poor diet, early life stress and other inflammatory factors contributing to a greater risk of developing AD. Here, we integrate evidence for the interface between these factors, and how they contribute to a pro-inflammatory brain milieu. In particular, we discuss the importance of appropriate polyunsaturated fatty acids (PUFA) in the diet for the metabolism of specialised pro-resolving mediators (SPMs); raising the possibility for dietary strategies to improve AD outlook.

Efficacy of acupuncture as adjunct therapy for sleep disorders in Parkinson's disease: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study was to summarize existing clinical studies through a systematic review to explore the efficacy of acupuncture in treating sleep disorders in PD patients.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we retrieved the papers through 30 April 2023 from eight databases. The experimental group was treated with acupuncture plus conventional therapy, while the control group was treated with conventional therapy alone or combined with sham acupuncture. The sleep quality was the primary outcome. A team of researchers meticulously performed literature screening, data extraction and risk of bias assessment following the Cochrane Handbook. A meta-analysis was synthesized using Review Manager Version 5.4 software if feasible. The quality of the evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

RESULTS

A total of 973 papers were identified, with 15 papers involving 957 patients were included in this systematic review. The results showed that acupuncture interventions included manual acupuncture, electroacupuncture, moxibustion and bleeding, with 1-7 times every week implemented during 2-12 weeks. Acupuncture as an adjunct therapy compared to conventional therapy alone showed better effect in sleep quality and overall symptoms of PD. Risk of bias assessment showed deficiencies in blinding and allocation concealment. All included studies were synthesized in a meta-analysis, as the result of which, acupuncture improved PDSS scores(MD =16.57; 95% CI, 7.24-25.90; I2 = 97%) and effective rate for sleep disorders (OR = 5.91; 95% CI, 1.71-20.39; I2 = 54%); meanwhile, acupuncture reduced UPDRS scores(MD = -4.29; 95% CI, -6.54 - -2.03; I2 = 77%) and improved effective rate for PD (OR = 3.22; 95% CI, 1.81-5.72; I2 = 0%). The quality of evidence ranged from low to moderate by GRADE.

CONCLUSION

This study provides initial evidence that acupuncture as an adjunct therapy might be associated with improvement of sleep disorders in PD. Due to the lack of high-quality studies, larger sample size studies with sham acupuncture groups should be conducted in future.

REGISTRATION NUMBER

CRD42022364249 (PROSPERO).

Sleep deprivation: A risk factor for the pathogenesis and progression of Alzheimer's disease

Sleep deprivation refers to an intentional or unintentional reduction in sleep time, resulting in insufficient sleep. It is often caused by sleep disorders, work demands (e.g., night shifts), and study pressure. Sleep deprivation promotes Aβ deposition and tau hyperphosphorylation, which is a risk factor for the pathogenesis and progression of Alzheimer's disease (AD). Recent research has demonstrated the potential involvement of sleep deprivation in both the pathogenesis and progression of AD through glial cell activation, the glial lymphatic system, orexin system, circadian rhythm system, inflammation, and the gut microbiota. Thus, investigating the molecular mechanisms underlying the association between sleep deprivation and AD is crucial, which may contribute to the development of preventive and therapeutic strategies for AD. This review aims to analyze the impact of sleep deprivation on AD, exploring the underlying pathological mechanisms that link sleep deprivation to the initiation and progression of AD, which offers a theoretical foundation for the development of drugs aimed at preventing and treating AD.

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.

Towards the neurobiology of insomnia: A systematic review of neuroimaging studies

Insomnia disorder signifies a major public health concern. The development of neuroimaging techniques has permitted to investigate brain mechanisms at a structural and functional level. The present systematic review aims at shedding light on functional, structural, and metabolic substrates of insomnia disorder by integrating the available published neuroimaging data. The databases PubMed, PsycARTICLES, PsycINFO, CINAHL and Web of Science were searched for case-control studies comparing neuroimaging data from insomnia patients and healthy controls. 85 articles were judged as eligible. For every observed finding of each study, the effect size was calculated from standardised mean differences, statistic parameters and figures, showing a marked heterogeneity that precluded a comprehensive quantitative analysis. From a qualitative point of view, considering the findings of significant group differences in the reported regions across the articles, this review highlights the major involvement of the anterior cingulate cortex, thalamus, insula, precuneus and middle frontal gyrus, thus supporting some central themes in the debate on the neurobiology of and offering interesting insights into the psychophysiology of sleep in this disorder.

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.

Time to Dementia Diagnosis Among Veterans with Comorbid Insomnia and Depressive Episodes

Background

Older adults with heart failure are at elevated risk of Alzheimer's disease and related dementias (AD/ADRD). Research suggests that insomnia and depressive episodes contribute somewhat dissociable impacts on risk for AD/ADRD in this patient population, although the temporal ordering of effects is unknown.

Objective

This study examined time to dementia diagnosis among patients with comorbid insomnia and/or depressive episodes in an epidemiological sample.

Methods

Secondary data analyses were conducted using a cohort study of 203,819 Veterans with a primary admission diagnosis of heart failure in 129 VA Medical Centers.

Results

Patients with diagnoses of both insomnia and depressive episodes had the shortest time to a dementia diagnosis at both 1-year (Hazard ratio = 1.43, 95% CI [1.36, 1.51]) and 3-year follow-up time points (Hazard ratio = 1.40, 95% CI [1.34, 1.47]) versus patients with one or neither comorbidity.

Conclusions

Individuals with both comorbidities had the shortest time to dementia onset. Screening for these comorbidities may help to identify patients at elevated risk of dementia who could benefit from enhanced monitoring or early intervention strategies for more rapid detection and management of dementia symptoms.

Thirty Risk Factors for Alzheimer's Disease Unified by a Common Neuroimmune-Neuroinflammation Mechanism

One of the major obstacles confronting the formulation of a mechanistic understanding for Alzheimer's disease (AD) is its immense complexity-a complexity that traverses the full structural and phenomenological spectrum, including molecular, macromolecular, cellular, neurological and behavioural processes. This complexity is reflected by the equally complex diversity of risk factors associated with AD. However, more than merely mirroring disease complexity, risk factors also provide fundamental insights into the aetiology and pathogenesis of AD as a neurodegenerative disorder since they are central to disease initiation and subsequent propagation. Based on a systematic literature assessment, this review identified 30 risk factors for AD and then extended the analysis to further identify neuroinflammation as a unifying mechanism present in all 30 risk factors. Although other mechanisms (e.g., vasculopathy, proteopathy) were present in multiple risk factors, dysfunction of the neuroimmune-neuroinflammation axis was uniquely central to all 30 identified risk factors. Though the nature of the neuroinflammatory involvement varied, the activation of microglia and the release of pro-inflammatory cytokines were a common pathway shared by all risk factors. This observation provides further evidence for the importance of immunopathic mechanisms in the aetiopathogenesis of AD.

Association of insomnia with incident chronic cognitive impairment in older adults with type 2 diabetes mellitus: A prospective study of the Hong Kong Diabetes Register

AIMS

To examine the risk association of insomnia with incident chronic cognitive impairment in older adults with type 2 diabetes mellitus (T2D).

METHODS

Between July 2010 and June 2015, patients with T2D aged ≥60 years enrolled in the Hong Kong Diabetes Register completed the Insomnia Severity Index (ISI) questionnaire. Patients were considered having insomnia if they had ISI score > 14. We prospectively followed up the cohort and censored outcome through reviewing diagnoses and clinical notes entered by attending physicians in electronic medical record to identify incident cases of mild cognitive impairment and dementia.

RESULTS

After excluding shift workers and those with established chronic cognitive impairment at baseline, we included 986 patients with T2D in this study (58.3 % men, mean age ± standard deviation: 62.5 ± 2.6 years, disease duration of diabetes: 10.7 ± 8.2 years, HbA1c: 7.4 ± 1.3 %, insulin users: 28.7 %, insomnia: 9.1 %). After a median follow-up of 7.6 (interquartile range = 2.0) years, 41 (4.2 %) developed chronic cognitive impairment. Using Cox regression analysis, insomnia (hazard ratio, HR 2.909, p = 0.012) and HbA1c ≥ 7 % (HR 2.300, p = 0.038) were positively associated with incident chronic cognitive impairment while insulin use (HR 0.309, p = 0.028) showed negative association.

CONCLUSIONS

Insomnia, suboptimal glycemic control and non-insulin use are independent risk factors for incident chronic cognitive impairment in older adults with T2D.

Neuroprotective effect of Kurarinone against corticosterone-induced cytotoxicity on rat hippocampal neurons by targeting BACE1 to activate P13K-AKT signaling - A potential treatment in insomnia disorder

The hippocampus has been implicated in the pathogenesis of insomnia disorder (ID) and the purpose of this study was to investigate the neuroprotective mechanism of the natural flavone Kurarinone (Kur) on hippocampal neurotoxicity as a potential treatment of ID. The effect of Kur on hippocampal neuronal cell (HNC) viability and apoptosis were assessed by Cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Then, the effect of Kur on β-site amyloid precursor protein-cleaving enzyme 1 (BACE1), brain-derived neurotrophic factor (BDNF), and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) phosphorylation level were measured by Western blot. Further, SwissTargetPrediction analysis and molecular docking experiments were used to detect a potential target of Kur. Then, the p-chlorophenylalanine (PCPA) model was established in vivo to further study the effect of BACE1 expression on Kur and HNC. As a result, HNC viability was only significantly decreased by 2 μM of Kur. Kur reversed the impacts of corticosterone upon inhibiting viability (0.25-1 μM), PI3K (0.5-1 μM)/AKT phosphorylation, and BDNF (1 μM) level, and enhancing the apoptosis (0.25-1 μM) and BACE1 expression (1 μM) in HNCs. BACE1 was a potential target of Kur. Notably, Kur (150 mg/kg) attenuated PCPA-induced upregulation of BACE1 expression in rat hippocampal tissues as ZRAS (0.8 g/kg). The effects of Kur (1 μM) on corticosterone-treated HNCs were reversed by BACE1 overexpression. Collectively, Kur downregulates BACE1 level to activate PI3K/AKT, thereby attenuating corticosterone-induced toxicity in HNCs, indicating that Kur possibly exerted a neuroprotective effect, which providing a new perspective for the treatment of insomnia disorders.

Natural Immunosuppressants as a Treatment for Chronic Insomnia Targeting the Inflammatory Response Induced by NLRP3/caspase-1/IL-1β Axis Activation: A Scooping Review

Chronic insomnia is an inflammatory-related disease with an important pathological basis for various diseases which is a serious threat to a person's physical and mental health. So far, many hypotheses have been proposed to explain the pathogenesis of insomnia, among which inflammatory mechanisms have become the focus of scientific attention. In this regard, the aim of the present scooping review is to evaluate the potential benefits of natural compounds in treatment of chronic insomnia targeting nucleotide-binding oligomerization domain (NOD)-like receptor-pyrin-containing protein 3 (NLRP3)/caspase-1/IL-1β axis as one of the most important activators of inflammatory cascades. The data show that compounds that have the potential to cause inflammation induce sleep disorders, and that inflammatory mediators are key molecules in regulating the sleep-related activity of neurons. In the inflammatory process of insomnia, the role of NLRP3 in the pathogenesis of insomnia has been gradually considered by researchers. NLRP3 is an intracellular sensor that recognizes the widest range of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). After identification and binding to damage factors, NLRP3 inflammasome is assembled to activate the caspase-1 and IL-1β. Increased production and secretion of IL-1β may be involved in central nervous system dysregulation of physiological sleep. The current scooping review reports the potential benefits of natural compounds that target NLRP3 inflammasome pathway activity and highlights the hypothesis which NLRP3 /caspase-1/IL-1β may serve as a potential therapeutic target for managing inflammation and improving symptoms in chronic insomnia.

Neuro-Navigated rTMS Improves Sleep and Cognitive Impairment via Regulating Sleep-Related Networks' Spontaneous Activity in AD Spectrum Patients

Study Objectives

By examining spontaneous activity changes of sleep-related networks in patients with the Alzheimer's disease (AD) spectrum with or without insomnia disorder (ID) over time via neuro-navigated repetitive transcranial magnetic stimulation (rTMS), we revealed the effect and mechanism of rTMS targeting the left-angular gyrus in improving the comorbidity symptoms of the AD spectrum with ID.

Methods

A total of 34 AD spectrum patients were recruited in this study, including 18 patients with ID and the remaining 16 patients without ID. All of them were measured for cognitive function and sleep by using the cognitive and sleep subscales of the neuropsychiatric inventory. The amplitude of low-frequency fluctuation changes in sleep-related networks was revealed before and after neuro-navigated rTMS treatment between these two groups, and the behavioral significance was further explored.

Results

Affective auditory processing and sensory-motor collaborative sleep-related networks with hypo-spontaneous activity were observed at baseline in the AD spectrum with ID group, while substantial increases in activity were evident at follow-up in these subjects. In addition, longitudinal affective auditory processing, sensory-motor and default mode collaborative sleep-related networks with hyper-spontaneous activity were also revealed at follow-up in the AD spectrum with ID group. In particular, longitudinal changes in sleep-related networks were associated with improvements in sleep quality and episodic memory scores in AD spectrum with ID patients.

Conclusion

We speculated that left angular gyrus-navigated rTMS therapy may enhance the memory function of AD spectrum patients by regulating the spontaneous activity of sleep-related networks, and it was associated with memory consolidation in the hippocampus-cortical circuit during sleep.

Clinical Trial Registration

The study was registered at the Chinese Clinical Trial Registry, registration ID: ChiCTR2100050496, China.

Economic burden of comorbid insomnia in 5 common medical disease subgroups

STUDY OBJECTIVES

Approximately 85% of insomnia co-occurs with other disorders. Whereas insomnia was once considered "secondary" to these disorders, it is now widely recognized as an independent condition warranting treatment. While it is clear that insomnia can affect the course of other medical conditions, there is scant literature on the economic impact of comorbid insomnia among patients with common medical conditions. The aim of this study was to determine the economic burden of comorbid insomnia in 5 medical diseases commonly associated with insomnia: type 2 diabetes mellitus (T2DM), cancer undergoing treatment, menopause undergoing hormone replacement therapy, osteoporosis, and Alzheimer's disease and related dementias (ADRDs).

METHODS

This retrospective cohort study used claims data from the IBM MarketScan Commercial and Medicare Supplemental Databases from January 1, 2014, through December 31, 2019. Insomnia and comorbid disease groups were defined using physician-assigned International Classification of Diseases diagnostic codes. Insomnia medication treatment was defined based on ≥1 prescription fills for the most commonly prescribed insomnia medications (zolpidem, low-dose trazodone, and benzodiazepines [as a class]). For each comorbid disease subgroup, 4 cohorts were created: (1) patients with either treated or untreated insomnia, (2) non-sleep-disordered controls, (3) patients with untreated insomnia, and (4) patients with treated insomnia.

RESULTS

Sample sizes for individuals with comorbid insomnia ranged from 23,168 (T2DM) to 3,015 (ADRDs). Within each disease subgroup and relative to non-sleep-disordered controls, patients with comorbid insomnia demonstrated greater adjusted health care resource utilization and costs across most points of service. Likewise, relative to individuals with untreated insomnia, those with treated insomnia generally demonstrated greater adjusted health care resource utilization and costs.

CONCLUSIONS

In this national analysis, both untreated comorbid insomnia and comorbid insomnia treated with commonly prescribed insomnia medications were associated with increased health care resource utilization and costs across most points of service.

CITATION

Wickwire EM, Juday TR, Kelkar M, Heo J, Margiotta C, Frech FH. Economic burden of comorbid insomnia in 5 common medical disease subgroups. J Clin Sleep Med. 2023;19(7):1293-1302.

Contribution of Chronic Sleep Deprivation to Age-Related Neurodegeneration in a Mouse Model of Familial Alzheimer's Disease (5xFAD)

Sleep-wake cycle disorders most often accompany the elderly and are frequently associated with the development of neurodegenerative processes, primarily Alzheimer's disease. Sleep disturbances can be diagnosed in patients with AD even before the onset of memory and cognitive impairment, and become more pronounced as the disease progresses. Therefore, the expansion of our knowledge of how sleep relates to AD pathogenesis needs to be addressed as soon as possible. Here, we investigated the influence of chronic sleep deprivation on the motor and orienting-exploratory activity of 5xFAD mice, as well as their spatial learning ability and long-term memory retention. The studies carried out revealed that chronic sleep deprivation negatively affects the processes of spatial memory reconsolidation in 5xFAD mice. This leads to the development of stress-related behavioral responses, including aggressive behavior. In addition, the morphological changes in the cerebral cortex, including changes in the nuclear-cytoplasmic ratio and degradation of neuronal processes are observed. Moreover, we found an increase in the level of total DNA methylation in the blood of the sleep-deprived mice, which may be one of the mechanisms of the two-way relationship between sleep and neurodegeneration.

Multiomics analysis of human peripheral blood reveals marked molecular profiling changes caused by one night of sleep deprivation

Sleep insufficiency is associated with various disorders; the molecular basis is unknown until now. Here, 14 males and 18 females were subjected to short-term (24 h) sleep deprivation, and donated fasting blood samples prior to (day 1) and following (days 2 and 3) short-term sleep deprivation. We used multiple omics techniques to examine changes in volunteers' blood samples that were subjected to integrated, biochemical, transcriptomic, proteomic, and metabolomic analyses. Sleep deprivation caused marked molecular changes (46.4% transcript genes, 59.3% proteins, and 55.6% metabolites) that incompletely reversed by day 3. The immune system in particular neutrophil-mediated processes associated with plasma superoxidase dismutase-1 and S100A8 gene expression was markedly affected. Sleep deprivation decreased melatonin levels and increased immune cells, inflammatory factors and c-reactive protein. By disease enrichment analysis, sleep deprivation induced signaling pathways for schizophrenia and neurodegenerative diseases enriched. In sum, this is the first multiomics approach to show that sleep deprivation causes prominent immune changes in humans, and clearly identified potential immune biomarkers associated with sleep deprivation. This study indicated that the blood profile following sleep disruption, such as may occur among shift workers, may induce immune and central nervous system dysfunction.

Risk of neurodegenerative diseases in patients with sleep disorders: A nationwide population-based case-control study

OBJECTIVE

Our study aimed to explore the associative relationship between neurodegenerative diseases and sleep disorders.

PATIENTS

This 15-year retrospective longitudinal nationwide population-based matched case-control study used data extracted from the National Health Insurance Research Database. We evaluated 25,589 patients diagnosed with neurodegenerative diseases between 2000 and 2015 and a matched control of 102,356 patients without neurodegenerative diseases.

RESULTS

Sleep disorders were an independent risk factor for the development of neurodegenerative diseases (adjusted odds ratio (OR): 1.794, 95% confidence interval (CI): 1.235-2.268, P < 0.001), with a positive dose-effect relationship (adjusted OR (95% CI): <1 year: 1.638 (1.093-2.872), P < 0.001; 1-5 years: 1.897 (1.260-3.135), P < 0.001; >5 years: 2.381 (1.467-3.681), P < 0.001. Moreover, patients with sleep disorder and comorbid depression had a significantly higher risk of neurodegenerative disorders (adjusted OR: 5.874). Subgroup analysis showed that insomnia was associated with Alzheimer's disease, Pick's disease and essential tremor (adjusted OR (95% CI): 1.555 (1.069-1.965), 1.934 (1.331-2.445) and 2.089 (1.439-2.648), respectively). Obstructive sleep apnea was associated with Parkinson's disease, essential tremor, and primary dystonia (adjusted OR (95% CI): 1.801 (1.239-2.275), 5.523 (3.802-6.977), and 4.892 (3.365-6.178), respectively). Other specific sleep disorders were associated with Pick's disease, Parkinson's disease, essential tremor, and primary dystonia (adjusted OR (95% CI): 8.901 (6.101-11.010), 1.549 (1.075-1.986), 2.791 (1.924-3.531), and 9.114 (6.283-10.506), respectively).

CONCLUSION

Sleep disorders are associated with the subsequent development of neurodegenerative disorders. Moreover, sleep disorder patients with comorbid depression have a higher risk of neurodegenerative diseases.

Analysis of circadian rhythm components in EEG/EMG data of aged mice

Aging disrupts circadian clocks, as evidenced by a reduction in the amplitude of circadian rhythms. Because the circadian clock strongly influences sleep-wake behavior in mammals, age-related alterations in sleep-wake patterns may be attributable, at least partly, to functional changes in the circadian clock. However, the effect of aging on the circadian characteristics of sleep architecture has not been well assessed, as circadian behaviors are usually evaluated through long-term behavioral recording with wheel-running or infrared sensors. In this study, we examined age-related changes in circadian sleep-wake behavior using circadian components extracted from electroencephalography (EEG) and electromyography (EMG) data. EEG and EMG were recorded from 12 to 17-week-old and 78 to 83-week-old mice for 3 days under light/dark and constant dark conditions. We analyzed time-dependent changes in the duration of sleep. Rapid eye movement (REM) and non-REM (NREM) sleep significantly increased during the night phase in old mice, whereas no significant change was observed during the light phase. The circadian components were then extracted from the EEG data for each sleep-wake stage, revealing that the circadian rhythm in the power of delta waves during NREM sleep was attenuated and delayed in old mice. Furthermore, we used machine learning to evaluate the phase of the circadian rhythm, with EEG data serving as the input and the phase of the sleep-wake rhythm (environmental time) as the output. The results indicated that the output time for the old mice data tended to be delayed, specifically at night. These results indicate that the aging process significantly impacts the circadian rhythm in the EEG power spectrum despite the circadian rhythm in the amounts of sleep and wake attenuated but still remaining in old mice. Moreover, EEG/EMG analysis is useful not only for evaluating sleep-wake stages but also for circadian rhythms in the brain.

Assessing a Sleep Interviewing Chatbot to Improve Subjective and Objective Sleep: Protocol for an Observational Feasibility Study

BACKGROUND

Sleep disorders are common among the aging population and people with neurodegenerative diseases. Sleep disorders have a strong bidirectional relationship with neurodegenerative diseases, where they accelerate and worsen one another. Although one-to-one individual cognitive behavioral interventions (conducted in-person or on the internet) have shown promise for significant improvements in sleep efficiency among adults, many may experience difficulties accessing interventions with sleep specialists, psychiatrists, or psychologists. Therefore, delivering sleep intervention through an automated chatbot platform may be an effective strategy to increase the accessibility and reach of sleep disorder intervention among the aging population and people with neurodegenerative diseases.

OBJECTIVE

This work aims to (1) determine the feasibility and usability of an automated chatbot (named MotivSleep) that conducts sleep interviews to encourage the aging population to report behaviors that may affect their sleep, followed by providing personalized recommendations for better sleep based on participants' self-reported behaviors; (2) assess the self-reported sleep assessment changes before, during, and after using our automated sleep disturbance intervention chatbot; (3) assess the changes in objective sleep assessment recorded by a sleep tracking device before, during, and after using the automated chatbot MotivSleep.

METHODS

We will recruit 30 older adult participants from West London for this pilot study. Each participant will have a sleep analyzer installed under their mattress. This contactless sleep monitoring device passively records movements, heart rate, and breathing rate while participants are in bed. In addition, each participant will use our proposed chatbot MotivSleep, accessible on WhatsApp, to describe their sleep and behaviors related to their sleep and receive personalized recommendations for better sleep tailored to their specific reasons for disrupted sleep. We will analyze questionnaire responses before and after the study to assess their perception of our proposed chatbot; questionnaire responses before, during, and after the study to assess their subjective sleep quality changes; and sleep parameters recorded by the sleep analyzer throughout the study to assess their objective sleep quality changes.

RESULTS

Recruitment will begin in May 2023 through UK Dementia Research Institute Care Research and Technology Centre organized community outreach. Data collection will run from May 2023 until December 2023. We hypothesize that participants will perceive our proposed chatbot as intelligent and trustworthy; we also hypothesize that our proposed chatbot can help improve participants' subjective and objective sleep assessment throughout the study.

CONCLUSIONS

The MotivSleep automated chatbot has the potential to provide additional care to older adults who wish to improve their sleep in more accessible and less costly ways than conventional face-to-face therapy.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/45752.

Wake Up America: National Survey of Patients’ and Physicians’ Views and Attitudes on Insomnia Care

While both patients and physicians consider sleep to be important, sleep health may not receive appropriate consideration during patient visits with health care professionals (HCPs). We completed the first large-scale survey of people with trouble sleeping (PWTS) and physicians who treat insomnia to understand their perspectives and potential discrepancies between them. The Harris Poll conducted online surveys of adult PWTS and HCPs (primary care physicians [PCPs] and psychiatrists) in the United States from September to October 2021. Respondents included 1001 PWTS, 300 PCPs, and 152 psychiatrists. Most HCPs agreed that sleep is critical to good health, yet very few reported routinely conducting full sleep histories on their patients. Approximately 30% of PWTS reported that their PCP never asks about sleep; zero HCPs in this survey reported “never” inquiring. Few HCPs reported being “very satisfied” with current treatment options; 50% of PCPs reported their patients being satisfied. Two-thirds of PWTS did not believe current treatment options adequately improved their sleep. This survey provides evidence that both PWTS and physicians agreed on the importance of sleep, but that treatment is often perceived as ineffective. This survey identifies a need for HCPs to address insomnia management and treatment gaps.

The Effect of Chinese Agarwood Essential Oil with Cyclodextrin Inclusion against PCPA-Induced Insomnia Rats

OBJECTIVE

To study the extraction process of agarwood active ingredients (AA) and investigate the safety and effectiveness of AA in the treatment of insomnia rats by nasal administration.

METHOD

A β-cyclodextrin (β-CD) inclusion compound (a-β-CD) was prepared from agarwood essential oil (AEO), and the preparation process was optimized and characterized. The safety of AA in nasal mucosa was evaluated through Bufo gargarizans maxillary mucosa and rat nasal mucosa models. Insomnia animal models were replicated by injecting p-chlorophenylalanine (PCPA), conducting behavioral tests, and detecting the expression levels of monoamine neurotransmitters (NE and 5-HT) and amino acids (GABA/Glu) in the rat hypothalamus.

RESULTS

The optimum inclusion process conditions of β-CD were as follows: the feeding ratio was 0.35:1.40 (g:g), the inclusion temperature was 45 °C, the inclusion time was 2 h, and the ICY% and IEO% were 53.78 ± 2.33% and 62.51 ± 3.21%, respectively. The inclusion ratio, temperature, and time are the three factors that have significant effects on the ICY% and IEO% of a-β-CD. AA presented little damage to the nasal mucosa. AA increased the sleep rate, shortened the sleep latency, and prolonged the sleep time of the rats. The behavioral test results showed that AA could ameliorate depression in insomnia rats to a certain extent. The effect on the expression of monoamine neurotransmitters and amino acids in the hypothalamus of rats showed that AA could significantly reduce NE levels and increase the 5-HT level and GABA/Glu ratio in the hypothalamus of insomnia rats.

CONCLUSION

The preparation of a-β-CD from AEO can reduce its irritation, improve its stability, increase its curative effect, and facilitate its storage and transport. AA have certain therapeutic effects on insomnia. The mechanism of their effect on rat sleep may involve regulating the expression levels of monoamine neurotransmitters and amino acids in the hypothalamus.

Amyloid-β in Alzheimer's disease - front and centre after all?

The amyloid hypothesis, which proposes that accumulation of the peptide amyloid-β at synapses is the key driver of Alzheimer's disease (AD) pathogenesis, has been the dominant idea in the field of Alzheimer's research for nearly 30 years. Recently, however, serious doubts about its validity have emerged, largely motivated by disappointing results from anti-amyloid therapeutics in clinical trials. As a result, much of the AD research effort has shifted to understanding the roles of a variety of other entities implicated in pathogenesis, such as microglia, astrocytes, apolipoprotein E and several others. All undoubtedly play an important role, but the nature of this has in many cases remained unclear, partly due to their pleiotropic functions. Here, we propose that all of these AD-related entities share at least one overlapping function, which is the local regulation of amyloid-β levels, and that this may be critical to their role in AD pathogenesis. We also review what is currently known of the actions of amyloid-β at the synapse in health and disease, and consider in particular how it might interact with the key AD-associated protein tau in the disease setting. There is much compelling evidence in support of the amyloid hypothesis; rather than detract from this, the implication of many disparate AD-associated cell types, molecules and processes in the regulation of amyloid-β levels may lend further support.

Sleep Disturbances Predict Cognitive Decline in Cognitively Healthy Adults

BACKGROUND

The effect of nighttime behaviors on cognition has not been studied independently from other neuropsychiatric symptoms.

OBJECTIVE

We evaluate the following hypotheses that sleep disturbances bring increased risk of earlier cognitive impairment, and more importantly that the effect of sleep disturbances is independent from other neuropsychiatric symptoms that may herald dementia.

METHODS

We used the National Alzheimer's Coordinating Center database to evaluate the relationship between Neuropsychiatric Inventory Questionnaire (NPI-Q) determined nighttime behaviors which served as surrogate for sleep disturbances and cognitive impairment. Montreal Cognitive Assessment scores defined two groups: conversion from 1) normal to mild cognitive impairment (MCI) and 2) MCI to dementia. The effect of nighttime behaviors at initial visit and covariates of age, sex, education, race, and other neuropsychiatric symptoms (NPI-Q), on conversion risk were analyzed using Cox regression.

RESULTS

Nighttime behaviors predicted earlier conversion time from normal cognition to MCI (hazard ratio (HR): 1.09; 95% CI: [1.00, 1.48], p = 0.048) but were not associated with MCI to dementia conversion (HR: 1.01; [0.92, 1.10], p = 0.856). In both groups, older age, female sex, lower education, and neuropsychiatric burden increased conversion risk.

CONCLUSION

Our findings suggest that sleep disturbances predict earlier cognitive decline independently from other neuropsychiatric symptoms that may herald dementia.

Nanowired Delivery of Cerebrolysin Together with Antibodies to Amyloid Beta Peptide, Phosphorylated Tau, and Tumor Necrosis Factor Alpha Induces Superior Neuroprotection in Alzheimer's Disease Brain Pathology Exacerbated by Sleep Deprivation

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AβP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AβP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.

Melatonin as a Harmonizing Factor of Circadian Rhythms, Neuronal Cell Cycle and Neurogenesis: Additional Arguments for Its Therapeutic Use in Alzheimer's Disease

The synthesis and release of melatonin in the brain harmonize various physiological functions. The apparent decline in melatonin levels with advanced aging is an aperture to the neurodegenerative processes. It has been indicated that down regulation of melatonin leads to alterations of circadian rhythm components, which further causes a desynchronization of several genes and results in an increased susceptibility to develop neurodegenerative diseases. Additionally, as circadian rhythms and memory are intertwined, such rhythmic disturbances influence memory formation and recall. Besides, cell cycle events exhibit a remarkable oscillatory system, which is downstream of the circadian phenomena. The linkage between the molecular machinery of the cell cycle and complex fundamental regulatory proteins emphasizes the conjectural regulatory role of cell cycle components in neurodegenerative disorders such as Alzheimer's disease. Among the mechanisms intervening long before the signs of the disease appear, the disturbances of the circadian cycle, as well as the alteration of the machinery of the cell cycle and impaired neurogenesis, must hold our interest. Therefore, in the present review, we propose to discuss the underlying mechanisms of action of melatonin in regulating the circadian rhythm, cell cycle components and adult neurogenesis in the context of AD pathogenesis with the view that it might further assist to identify new therapeutic targets.

Circadian dysregulation and Alzheimer’s disease: A comprehensive review

Alzheimer’s disease (AD), the foremost variant of dementia, has been associated with a menagerie of risk factors, many of which are considered to be modifiable. Among these modifiable risk factors is circadian rhythm, the chronobiological system that regulates sleep‐wake cycles, food consumption timing, hydration timing, and immune responses amongst many other necessary physiological processes. Circadian rhythm at the level of the suprachiasmatic nucleus (SCN), is tightly regulated in the human body by a host of biomolecular substances, principally the hormones melatonin, cortisol, and serotonin. In addition, photic information projected along afferent pathways to the SCN and peripheral oscillators regulates the synthesis of these hormones and mediates the manner in which they act on the SCN and its substructures. Dysregulation of this cycle, whether induced by environmental changes involving irregular exposure to light, or through endogenous pathology, will have a negative impact on immune system optimization and will heighten the deposition of Aβ and the hyperphosphorylation of the tau protein. Given these correlations, it appears that there is a physiologic association between circadian rhythm dysregulation and AD. This review will explore the physiology of circadian dysregulation in the AD brain, and will propose a basic model for its role in AD‐typical pathology, derived from the literature compiled and referenced throughout.

Sleep medicine: Practice, challenges and new frontiers

Sleep medicine is an ambitious cross-disciplinary challenge, requiring the mutual integration between complementary specialists in order to build a solid framework. Although knowledge in the sleep field is growing impressively thanks to technical and brain imaging support and through detailed clinic-epidemiologic observations, several topics are still dominated by outdated paradigms. In this review we explore the main novelties and gaps in the field of sleep medicine, assess the commonest sleep disturbances, provide advices for routine clinical practice and offer alternative insights and perspectives on the future of sleep research.

Network meta-analysis comparing the effectiveness of a prescription digital therapeutic for chronic insomnia to medications and face-to-face cognitive behavioral therapy in adults

OBJECTIVE

The purpose of this study was to compare the effectiveness of the only Food and Drug Administration-authorized prescription digital therapeutic (PDT) Somryst versus face-to-face cognitive behavioral therapy for insomnia (CBT-I), or FDA-approved prescription medications for insomnia.

METHODS

A systematic literature review was undertaken to identify relevant studies. A Bayesian network meta-analysis (NMA) was conducted to examine (1) mean change in insomnia severity index (ISI); (2) proportional change in ISI remitters; (3) mean change in wake after sleep onset (WASO); and (4) mean change in sleep onset latency (SOL).

RESULTS

Twenty studies provided data on the PDT, CBT-I, CBT-I in combination with self-help (SH), or two prescription medications (eszopiclone and zolpidem). The PDT was associated with significant mean change in ISI (-5.77, 95% Credible Interval [CrI] - 8.53, -3.07) and ISI remitters (OR 12.33; 95% CrI 2.28, 155.91) compared to placebo, and had the highest probability of being the most effective treatment overall for ISI mean change (56%), and ISI remitters (64%). All evaluated interventions significantly outperformed placebo for WASO but no significant differences were observed for SOL (five interventions). Sensitivity analyses excluding medications and meta-regression (assessing type, duration, delivery method for CBT-I) did not affect NMA results.

CONCLUSIONS

This network meta-analysis demonstrated that a PDT delivering CBT-I had the highest probability of being most effective compared to face-to-face CBT-I, prescription sleep medications, or placebo, as measured by reductions in mean ISI score from baseline and ISI-determined remittance.

The Polygenic Risk Score Knowledge Base offers a centralized online repository for calculating and contextualizing polygenic risk scores

The process of identifying suitable genome-wide association (GWA) studies and formatting the data to calculate multiple polygenic risk scores on a single genome can be laborious. Here, we present a centralized polygenic risk score calculator currently containing over 250,000 genetic variant associations from the NHGRI-EBI GWAS Catalog for users to easily calculate sample-specific polygenic risk scores with comparable results to other available tools. Polygenic risk scores are calculated either online through the Polygenic Risk Score Knowledge Base (PRSKB; https://prs.byu.edu ) or via a command-line interface. We report study-specific polygenic risk scores across the UK Biobank, 1000 Genomes, and the Alzheimer's Disease Neuroimaging Initiative (ADNI), contextualize computed scores, and identify potentially confounding genetic risk factors in ADNI. We introduce a streamlined analysis tool and web interface to calculate and contextualize polygenic risk scores across various studies, which we anticipate will facilitate a wider adaptation of polygenic risk scores in future disease research.

IL-1α and TNF-α as an inducer for ROS-mediated NLRP1/NLRP3 inflammasomes activation in mononuclear blood cells from individuals with chronic insomnia disorder

BACKGROUND

There are some evidence that cytokines may play an important role in sleep deprivation; however, the underlying mechanisms are still unknown. So, the present study aim to evaluate the relationship between NLRP1 and NLRP3 inflammasomes activation of blood cells and serum levels of cytokines in individuals with chronic insomnia disorder (CID).

METHODS

Blood samples were collected from 24 individuals with CID and 24 healthy volunteers. The inflammasomes activation was evaluated using real time PCR of NLRP1, NLRP3, ASC, and Caspase-1; western blot of NLRP1 and NLRP3; caspase-1 activity assay; and serum levels of IL-1β, IL-18 and other cytokines using enzyme-linked immunosorbent assay (ELISA). ROS generation in blood cells were detected by flow cytometry assay. As well, MRI scans were obtained on a Siemens Magnetom Avanto 1.5 T MRI whole body scanner using an 8-channel head coil.

RESULTS

We found the increased activity of NLRP1 and NLRP3 inflammasomes in blood cells; the increased serum levels of pro-inflammatory cytokines; and the decreased serum levels of IL-10 and TGF-β in individuals with CID. We observed significant correlation between increased serum concentration of IL-1β and the severity of insomnia in individuals with CID. The levels of ROS in blood cells was found to be correlated with IL-1α and TNF-α concentrations in serums from individuals with CID. Moreover, the included individuals with CID demonstrated the increased right-cerebellum-cortex and lateral ventricle MD bilaterally compared to controls.

CONCLUSIONS

This study provided new insights on the pathogenesis of CID and the effects of cytokines on inflammasome activation.

Real-World Evaluation of Clinical Response and Long-Term Healthcare Resource Utilization Patterns Following Treatment with a Digital Therapeutic for Chronic Insomnia

Background and Objectives

This analysis evaluated insomnia severity and long-term impact on healthcare resource utilization (HCRU) and costs after treatment with Somryst^® (previously called SHUTi), a digital therapeutic delivering cognitive behavioral therapy for insomnia (CBT-I).

Methods

Change from baseline in insomnia severity index (ISI) score was assessed using last observed ISI score. A pre/post analysis of claims data was conducted, comparing HCRU in patients with self-identified sleep problems who successfully initiated the therapeutic (index date) between June 1, 2016 and December 31, 2018.

Results

A total of 248 patients were analyzed (median age 56.5 years, 57.3% female, mean ISI score 19.13, 52.4% treated with sleep aid medications pre-index). After 9 weeks, mean ISI score declined by 37.2% from baseline (19.1 vs 12.0), 58.8% of patients achieved ISI responder status (ISI score improved by =>7; NNT: 1.7), and 26.6% of patients achieved insomnia remission (ISI score <8; NNT for remission: 3.8). After two-year follow-up, post-index events were reduced (compared to 2 years pre-index) for emergency department visits (-53%; IRR: 0.47; 95% CI 0.27, 0.82; P=0.008), hospiatizations (-21%; IRR: 0.79; 95% CI 0.46, 1.35; P=0.389) and hospital outpatient visits (-13%; IRR: 0.87; 95% CI 0.66, 1.14; P=0.315). Slightly increased rates were observed for ambulatory surgical center visits (2%; IRR: 1.02; 95% CI 0.73, 1.44; P=0.903) and office visits (2%; IRR: 1.02; 95% CI 0.92, 1.14; P=0.672). The number of patients treated with sleep aid medications dropped 18.5% (52.4% pre-index vs 42.7% post-index). Average number of prescriptions decreased from 3.98 pre-index to 3.73 post-index (P= 0.552). Total two-year cost reduction post-index vs pre-index was $510,678, or -$2059 per patient.

Conclusion

In a real-world cohort of patients with chronic insomnia, treatment with a digital therapeutic delivering CBT-I was associated with reductions in insomnia severity, emergency department visits, and net costs.

A Dichotomous Role for FABP7 in Sleep and Alzheimer's Disease Pathogenesis: A Hypothesis

Fatty acid binding proteins (FABPs) are a family of intracellular lipid chaperone proteins known to play critical roles in the regulation of fatty acid uptake and transport as well as gene expression. Brain-type fatty acid binding protein (FABP7) is enriched in astrocytes and has been implicated in sleep/wake regulation and neurodegenerative diseases; however, the precise mechanisms underlying the role of FABP7 in these biological processes remain unclear. FABP7 binds to both arachidonic acid (AA) and docosahexaenoic acid (DHA), resulting in discrete physiological responses. Here, we propose a dichotomous role for FABP7 in which ligand type determines the subcellular translocation of fatty acids, either promoting wakefulness aligned with Alzheimer's pathogenesis or promoting sleep with concomitant activation of anti-inflammatory pathways and neuroprotection. We hypothesize that FABP7-mediated translocation of AA to the endoplasmic reticulum of astrocytes increases astrogliosis, impedes glutamatergic uptake, and enhances wakefulness and inflammatory pathways via COX-2 dependent generation of pro-inflammatory prostaglandins. Conversely, we propose that FABP7-mediated translocation of DHA to the nucleus stabilizes astrocyte-neuron lactate shuttle dynamics, preserves glutamatergic uptake, and promotes sleep by activating anti-inflammatory pathways through the peroxisome proliferator-activated receptor-γ transcriptional cascade. Importantly, this model generates several testable hypotheses applicable to other neurodegenerative diseases, including amyotrophic lateral sclerosis and Parkinson's disease.

Sleep and Late-Onset Alzheimer's Disease: Shared Genetic Risk Factors, Drug Targets, Molecular Mechanisms, and Causal Effects

Late-onset Alzheimer's disease (AD) is associated with sleep-related phenotypes (SRPs). The fact that whether they share a common genetic etiology remains largely unknown. We explored the shared genetics and causality between AD and SRPs by using high-definition likelihood (HDL), cross-phenotype association study (CPASSOC), transcriptome-wide association study (TWAS), and bidirectional Mendelian randomization (MR) in summary-level data for AD (N = 455,258) and summary-level data for seven SRPs (sample size ranges from 359,916 to 1,331,010). AD shared a strong genetic basis with insomnia (r _g = 0.20; p = 9.70 × 10^-5), snoring (r _g = 0.13; p = 2.45 × 10^-3), and sleep duration (r _g = -0.11; p = 1.18 × 10^-3). The CPASSOC identifies 31 independent loci shared between AD and SRPs, including four novel shared loci. Functional analysis and the TWAS showed shared genes were enriched in liver, brain, breast, and heart tissues and highlighted the regulatory roles of immunological disorders, very-low-density lipoprotein particle clearance, triglyceride-rich lipoprotein particle clearance, chylomicron remnant clearance, and positive regulation of T-cell-mediated cytotoxicity pathways. Protein-protein interaction analysis identified three potential drug target genes (APOE, MARK4, and HLA-DRA) that interacted with known FDA-approved drug target genes. The CPASSOC and TWAS demonstrated three regions 11p11.2, 6p22.3, and 16p11.2 may account for the shared basis between AD and sleep duration or snoring. MR showed insomnia had a causal effect on AD (OR_IVW = 1.02, P _IVW = 6.7 × 10^-6), and multivariate MR suggested a potential role of sleep duration and major depression in this association. Our findings provide strong evidence of shared genetics and causation between AD and sleep abnormalities and advance our understanding of the genetic overlap between them. Identifying shared drug targets and molecular pathways can be beneficial for treating AD and sleep disorders more efficiently.