Association between sleep duration and possible sarcopenia in middle-aged and elderly Chinese individuals: evidence from the China health and retirement longitudinal study.

BACKGROUND: Sarcopenia is a common cause of disability in the aging population, and managing sarcopenia is an important step in building intrinsic capacity and promoting healthy aging. A growing body of evidence suggests that sleep deprivation may be a mediator of the development of sarcopenia. The purpose of this study was to explore the longitudinal association between sleep duration and possible sarcopenia using data from a national sample. METHODS: Two waves of data from the CHARLS database for 2011 and 2015 were used in this study. All possible sarcopenia participants met the Asia Working Group for Sarcopenia 2019 (AWGS 2019) diagnostic criteria. Sleep duration was assessed using a self-report questionnaire, and sleep duration was categorized as short (≤ 6 h), medium (6-8 h), or long (> 8 h) based on previous studies. Longitudinal associations between sleep duration and possible sarcopenia will be calculated by univariate and multifactorial logistic regression analyses and expressed as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: A total of 5654 individuals participated in the follow-up study, with a prevalence of possible sarcopenia of 53.72% (578) in the short sleep duration group, 38.29% (412) in the medium sleep duration group, and 7.99% (86) in the long sleep duration group. According to the crude model of the second-wave follow-up study, short sleep durations were significantly more strongly associated with possible sarcopenia than were medium and long sleep durations (OR: 1.35, 95% CI: 1.17-1.55, P = 0.000). The association between short sleep duration and possible sarcopenia was maintained even after adjustment for covariates such as age, gender, residence, education level, BMI, smoking status, alcohol consumption and comorbidities (OR: 1.18, 95% CI: 1.02-1.36, P = 0.029). In the subgroup analysis, short sleep duration was associated with low grip strength (OR: 1.20, 95% CI: 1.02-1.41, P = 0.031). CONCLUSIONS: Sleep deprivation may be closely associated with the development of possible sarcopenia in middle-aged and elderly people, which provides new insights and ideas for sarcopenia intervention, and further studies are needed to reveal the underlying mechanisms involved.

Photobiomodulation under Electroencephalographic Controls of Sleep for Stimulation of Lymphatic Removal of Toxins from Mouse Brain.

The meningeal lymphatic vessels (MLVs) play an important role in the removal of toxins from the brain. The development of innovative technologies for the stimulation of MLV functions is a promising direction in the progress of the treatment of various brain diseases associated with MLV abnormalities, including Alzheimer's and Parkinson's diseases, brain tumors, traumatic brain injuries, and intracranial hemorrhages. Sleep is a natural state when the brain's drainage processes are most active. Therefore, stimulation of the brain's drainage and MLVs during sleep may have the most pronounced therapeutic effects. However, such commercial technologies do not currently exist. This study presents a new portable technology of transcranial photobiomodulation (tPBM) under electroencephalographic (EEG) control of sleep designed to photo-stimulate removal of toxins (e.g., soluble amyloid beta (Aß)) from the brain of aged BALB/c mice with the ability to compare the therapeutic effectiveness of different optical resources. The technology can be used in the natural condition of a home cage without anesthesia, maintaining the motor activity of mice. These data open up new prospects for developing non-invasive and clinically promising photo-technologies for the correction of age-related changes in the MLV functions and brain's drainage processes and for effectively cleansing brain tissues from metabolites and toxins. This technology is intended both for preclinical studies of the functions of the sleeping brain and for developing clinically relevant treatments for sleep-related brain diseases.

Reallocating just 10 min to moderate-to-vigorous physical activity from other components of 24-hour movement behaviors improves cardiovascular health in adults.

BACKGROUND: As components of a 24-hour day, sedentary behavior (SB), physical activity (PA), and sleep are all independently linked to cardiovascular health (CVH). However, insufficient understanding of components' mutual exclusion limits the exploration of the associations between all movement behaviors and health outcomes. The aim of this study was to employ compositional data analysis (CoDA) approach to investigate the associations between 24-hour movement behaviors and overall CVH. METHODS: Data from 581 participants, including 230 women, were collected from the 2005-2006 wave of the US National Health and Nutrition Examination Survey (NHANES). This dataset included information on the duration of SB and PA, derived from ActiGraph accelerometers, as well as self-reported sleep duration. The assessment of CVH was conducted in accordance with the criteria outlined in Life's Simple 7, encompassing the evaluation of both health behaviors and health factors. Compositional linear regression was utilized to examine the cross-sectional associations of 24-hour movement behaviors and each component with CVH score. Furthermore, the study predicted the potential differences in CVH score that would occur by reallocating 10 to 60 min among different movement behaviors. RESULTS: A significant association was observed between 24-hour movement behaviors and overall CVH (p < 0.001) after adjusting for potential confounders. Substituting moderate-to-vigorous physical activity (MVPA) for other components was strongly associated with favorable differences in CVH score (p < 0.05), whether in one-for-one reallocations or one-for-remaining reallocations. Allocating time away from MVPA consistently resulted in larger negative differences in CVH score (p < 0.05). For instance, replacing 10 min of light physical activity (LPA) with MVPA was related to an increase of 0.21 in CVH score (95% confidence interval (95% CI) 0.11 to 0.31). Conversely, when the same duration of MVPA was replaced with LPA, CVH score decreased by 0.67 (95% CI -0.99 to -0.35). No such significance was discovered for all duration reallocations involving only LPA, SB, and sleep (p > 0.05). CONCLUSIONS: MVPA seems to be as a pivotal determinant for enhancing CVH among general adult population, relative to other movement behaviors. Consequently, optimization of MVPA duration is an essential element in promoting overall health and well-being.

Restricted linear association between night sleep duration and diabetes risk in middle-aged and older adults: a 7-year follow-up analysis from the China health and retirement longitudinal study.

Background: A rapid increase in the prevalence of diabetes is an urgent public health concern among older adults, especially in developing countries such as China. Despite several studies on lifestyle factors causing diabetes, sleep, a key contributor, is understudied. Our study investigates the association between night sleep duration and diabetes onset over a 7-year follow-up to fill information gaps. Method: A population-based cohort study with 5437 respondents used 2011-2018 China Health and Retirement Longitudinal Study data. Using self-reported night sleep duration from the 2011 baseline survey, information on new-onset diabetes was collected in follow-up surveys. Baseline characteristics of participants with vs. without new-onset diabetes were compared using Chi-square and Mann-Whitney U tests. Multivariable Cox regression models estimated the independent relationship between night sleep and new-onset diabetes. The addictive Cox regression model approach and piece-wise regression described the nonlinear relationship between night sleep and new-onset diabetes. Subgroup analysis was also performed by age, gender, body measurement index, dyslipidemia, drinking status, smoking, hypertension, and afternoon napping duration. Result: 549 respondents acquired diabetes during a median follow-up of 84 months. After controlling for confounders, night sleep duration was substantially linked with new-onset diabetes in the multivariable Cox regression model. The risk of diabetes is lower for respondents who sleep longer than 5 hours, except for those who sleep over 8 hours [5.1-6h Hazard ratios (HR) [95% confidence intervals (CI)] = 0.71 (0.55, 0.91); 6.1-7h HR = 0.69 (0.53, 0.89); 7.1-8h HR = 0.58 (0.45, 0.76)]. Nonlinear connections were delineated by significant inflection points at 3.5 and 7.5 hours, with a negative correlation observed only between these thresholds. With one hour more night sleep, the risk of diabetes drops 15%. BMI and dyslipidemia were identified as modifiers when only consider the stand linear effect of sleep duration on diabetes. Conclusion: This study establishes a robust association between night sleep and new-onset diabetes in middle-aged and older Chinese individuals within the 3.5-7.5-hour range, offering a foundation for early glycemic management interventions in this demographic. The findings also underscore the pivotal role of moderate night sleep in preventing diabetes, marking a crucial juncture in community medical research.

Association between bedtime and female infertility: a secondary analysis from a cross-sectional study.

Objective: To evaluate the association between bedtime and infertility and to identify the optimal bedtime for women of reproductive age. Methods: We conducted a cross-sectional study using data from 3,903 female participants in the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2020. The effect of bedtime on female infertility was assessed using the binary logistic regression in different models, including crude model and adjusted models. To identify the non-linear correlation between bedtime and infertility, generalized additive models (GAM) were utilized. Subgroup analyses were conducted by age, body mass index (BMI), waist circumference, physical activity total time, marital status, smoking status, drinking status and sleep duration. Results: After adjusting for potential confounders (age, race, sleep duration, waist circumference, marital status, education, BMI, smoking status, drinking status and physical activity total time), a non-linear relationship was observed between bedtime and infertility, with the inflection point at 22:45. To the left side of the inflection point, no significant association was detected. However, to the right of it, bedtime was positively related to the infertility (OR: 1.22; 95% CI: 1.06 to 1.39; P = 0.0049). Subgroup analyses showed that late sleepers with higher BMI were more prone to infertility than those with a lower BMI (BMI: 25-30 kg/m2: OR: 1.26; 95% CI: 1.06 to 1.51; P = 0.0136; BMI ≥ 30 kg/m²: OR: 1.21, 95% CI: 1.09 to 1.34; P = 0.0014). Conclusion: Bedtime was non-linearly associated with infertility, which may provide guidance for sleep behavior in women of childbearing age.

Associations between Life's Essential 8 and depression among US adults.

Few studies have examined the association of Life's Essential 8 (LE8) with depression among US adults. This is a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2020. LE8 score was measured as the mean score of eight metrics (diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipid, blood glucose, and blood pressure). CVH was categorized into low, moderate, and high according to tertiles of LE8 score. Depression was defined based on the 9-Item Patient Health Questionnaire (PHQ-9). Weighted logistic regressions were conducted to assess the associations of depression with CVH. Compared with participants with low CVH, the fully adjusted ORs of depression were 0.45 (0.37, 0.55) in the moderate CVH and 0.21 (0.15, 0.30) in the high CVH participants, respectively. The results remained robust in subgroup and sensitivity analyses. All eight LE8 metrics were negatively associated with depression, while nicotine exposure and sleep health were identified as two major metrics contributing to the association. Better CVH evaluated by LE8 was associated with decreased depression prevalence among US adults. Adherence to a higher CVH score, especially targeting smoking cessation and proper sleep duration, might be beneficial for prevention of depression.

Chronic Astrocytic TNFα Production in the Preoptic-Basal Forebrain Causes Aging-like Sleep-Wake Disturbances in Young Mice.

Sleep disruption is a frequent problem of advancing age, often accompanied by low-grade chronic central and peripheral inflammation. We examined whether chronic neuroinflammation in the preoptic and basal forebrain area (POA-BF), a critical sleep-wake regulatory structure, contributes to this disruption. We developed a targeted viral vector designed to overexpress tumor necrosis factor-alpha (TNFα), specifically in astrocytes (AAV5-GFAP-TNFα-mCherry), and injected it into the POA of young mice to induce heightened neuroinflammation within the POA-BF. Compared to the control (treated with AAV5-GFAP-mCherry), mice with astrocytic TNFα overproduction within the POA-BF exhibited signs of increased microglia activation, indicating a heightened local inflammatory milieu. These mice also exhibited aging-like changes in sleep-wake organization and physical performance, including (a) impaired sleep-wake functions characterized by disruptions in sleep and waking during light and dark phases, respectively, and a reduced ability to compensate for sleep loss; (b) dysfunctional VLPO sleep-active neurons, indicated by fewer neurons expressing c-fos after suvorexant-induced sleep; and (c) compromised physical performance as demonstrated by a decline in grip strength. These findings suggest that inflammation-induced dysfunction of sleep- and wake-regulatory mechanisms within the POA-BF may be a critical component of sleep-wake disturbances in aging.

Association of total sleep duration variability with risk of new stroke in the middle-aged and elderly Chinese population.

OBJECTIVE: To investigate the association between total sleep duration variability and stroke in the middle-aged and elderly population in China. METHODS: Data were collected from the 2011, 2013, 2015, and 2018 surveys of the China Health and Retirement Longitudinal Study (CHARLS). A total of 3485 participants, who had not experienced a stroke until 2015 and completed the follow-up in 2018, were enrolled to analyze the relationship between total sleep duration variability and new stroke. Total sleep duration was calculated by summing self-reported nocturnal sleep duration and daytime napping. The variability was determined by calculating the standard deviation (SD) of total sleep duration across the first three waves. A binary logistic regression model was utilized to analyze this association. RESULTS: Of the 3485 participants, 183 (5.25%) sustained a stroke event. A dose-response relationship was observed, indicating an increased stroke risk of 0.2 per unit (hours) increase in total sleep duration variability [OR (95% CI): 1.20 (1.01-1.42)]. Upon stratification by sex groups, this increased risk was significant only in men [OR (95% CI): 1.44 (1.12-1.83)]. CONCLUSION: Increased total sleep duration variability was associated with an increased risk of stroke in the middle-aged and elderly, independent of factors such as age, nocturnal sleep duration, napping habits, region of residence, hypertension, diabetes mellitus, dyslipidemia, BMI, smoking, drinking habits, and marital status. However, a more notable correlation was observed in males.

Sleep, Nutrition, and Health Maintenance in Cardiothoracic Surgery.

Cardiothoracic surgeons work in high-intensity environments starting in surgical training and throughout their careers. They deal with critical patients. Their routine procedures are delicate, require extensive attention to detail, and can have detrimental effects on patients' lives. Cardiothoracic surgeons are required to perform at their best capacity incessantly. To do this, they must safeguard their mental and physical well-being. Preserving health through sleep, nutrition, exercise, and routine medical checkups ensures a cardiothoracic surgeon's well-being. Great personal effort and discipline is required to maintain health in a busy schedule. We offer our best recommendations from expert peers in the field.

Combined Aerobic and Resistance Training Improves Body Composition, Alters Cardiometabolic Risk, and Ameliorates Cancer-Related Indicators in Breast Cancer Patients and Survivors with Overweight/Obesity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Breast cancer survivors with obesity are at a high risk of cancer recurrence, comorbidity, and mortality. This review aims to systematically evaluate the effects of combined aerobic and resistance training (CART) on body composition, lipid homeostasis, inflammation, adipokines, cancer-related fatigue, sleep, and quality of life in breast cancer patients and survivors with overweight/obesity. An electronic search was conducted in PubMed, Web of Science, Scopus, Science Direct, Cochrane, and Google Scholar databases from inception up to January 8, 2024. Randomized controlled trials (RCTs) meeting the inclusion criteria were selected for the analysis. The Cochrane risk of bias tool was used to assess eligible studies, and the GRADE method to evaluate the quality of evidence. A random-effects model was used, and data were analyzed using mean (MD) and standardized mean differences (SMD) for continuous variables with 95% confidence intervals (CI). We assessed the data for risk of bias, heterogeneity, sensitivity, reporting bias, and quality of evidence. A total of 17 randomized controlled trials were included in the systematic review involving 1,148 female patients and survivors (mean age: 54.0 ± 3.4 years). The primary outcomes showed significant improvements in body mass index (SMD -0.57 kg/m2, p = 0.04), body fat (SMD -0.50%, p = 0.02), fat mass (SMD -0.63 kg, p = 0.04), hip circumference (MD -3.14 cm, p = 0.02), and fat-free mass (SMD 1.03 kg, p < 0.001). The secondary outcomes indicated significant increases in high-density lipoprotein cholesterol (MD -0.05 mmol/L, p = 0.008), natural killer cells (SMD 0.42%, p = 0.04), reductions in triglycerides (MD -81.90 mg/dL, p < 0.01), total cholesterol (SMD -0.95 mmol/L, p < 0.01), tumor necrosis factor α (SMD -0.89 pg/mL, p = 0.03), and leptin (SMD -0.63 ng/mL, p = 0.03). Also, beneficial alterations were found in cancer-related fatigue (SMD -0.98, p = 0.03), sleep (SMD -1.17, p < 0.001), and quality of life (SMD 2.94, p = 0.02) scores. There was very low to low confidence in the estimated effect of most of the outcomes. The present findings reveal that CART could be considered an adjunct therapy in supporting the conventional clinical approach observed following exercise. However, further high-quality research is needed to evaluate whether CART would be a valuable intervention to lower aggressive pharmacologic use in breast cancer patients with overweight/obesity.

Depressive symptom screening in elderly by passive sensing data of smartphones or smartwatches: A systematic review.

BACKGROUND: The elderly is commonly susceptible to depression, the symptoms for which may overlap with natural aging or other illnesses, and therefore miss being captured by routine screening questionnaires. Passive sensing data have been promoted as a tool for depressive symptoms detection though there is still limited evidence on its usage in the elderly. Therefore, this study aims to review current knowledge on the use of passive sensing data via smartphones and smartwatches in depressive symptom screening for the elderly. METHOD: The search of literature was performed in PubMed, IEEE Xplore digital library, and PsycINFO. Literature investigating the use of passive sensing data to screen, monitor, and/or predict depressive symptoms in the elderly (aged 60 and above) via smartphones and/or wrist-worn wearables was included for initial screening. Studies in English from international journals published between January 2012 to September 2022 were included. The reviewed studies were further analyzed by a narrative analysis. RESULTS: The majority of 21 included studies were conducted in Western countries with a few in Asia and Australia. Most studies adopted a cohort study design (n = 12), followed by cross-sectional design (n = 7) and a case-control design (n = 2). The most popular passive sensing data was related to sleep and physical activity using an actigraphy. Sleep characteristics, such as prolonged wakefulness after sleep onset, along with lower levels of physical activity, exhibited a significant association with depression. However, cohort studies expressed concerns regarding data quality stemming from incomplete follow-up and potential confounding effects. CONCLUSION: Passive sensing data, such as sleep, and physical activity parameters should be promoted for depressive symptoms detection. However, the validity, reliability, feasibility, and privacy concerns still need further exploration.

Endometroid type endometrial cancer after surgery: unravelling the interplay of sleep, fatigue, and psychological well-being.

BACKGROUND: Endometrioid carcinoma, originating in the endometrium glandular cells, is often detected early and treated by surgery. However, post-treatment life quality remains poorly studied, explicitly focusing on sleep quality, fatigue, and depression. METHODS: In this cross-sectional, observational study, 147 female patients with endometrioid-type endometrial carcinoma were evaluated using standardised tools-Pittsburgh Sleep Quality Index (PSQI), Fatigue Assessment Scale (FAS), and Beck Depression Inventory (BDI). Patients were categorised based on sleep quality and depression levels. The study employed correlation and regression analyses to examine the relationships among these variables. RESULTS: No correlations were found between sociodemographic or lifestyle variables and sleep quality, fatigue, or depression (P > 0.05). A strong correlation was identified between PSQI and FAS (r = 0.623; P < 0.001), PSQI and BDI (r = 0.291; P < 0.001), and FAS and BDI (r = 0.413; P < 0.001). Fatigue and tumour grade were potential predictors of poor sleep. Sleep quality and depression predicted fatigue, while only fatigue was a predictor for depression. Radiotherapy and external radiation rates were notably higher in the mild depression group. CONCLUSIONS: Our study suggests an imperative for integrated multi-disciplinary approaches that focus on medical and psychological aspects of patient care to enhance long-term well-being and quality of life.

Sleep and liver function biomarkers in relation to risk of incident liver cancer: a nationwide prospective cohort study.

BACKGROUND: To assess the largely undetermined separate and joint effects of sleep and liver function biomarkers on liver cancer. METHODS: Data of 356,894 participants without cancer at baseline in the UK Biobank were analyzed. Sleep score was evaluated using five sleep traits (sleep duration, chronotype, insomnia, snoring, and excessive daytime sleepiness) and dichotomized into healthy or unhealthy sleep. Circulating liver function biomarkers were measured. Cox proportional hazard model was performed to investigate the independent and joint associations of sleep and liver function biomarkers with liver cancer incidence. RESULTS: After a median follow-up time of 13.1 years, 394 cases of incident liver cancer were documented. The multivariable-adjusted hazard ratio (HR) for liver cancer was 1.46 (95% confidence interval: 1.15-1.85) associated with unhealthy sleep (vs. healthy sleep), and was 1.17 (1.15-1.20), 1.20 (1.18-1.22), 1.69 (1.47-1.93), 1.06 (1.06-1.07), 1.08 (1.07-1.09), 1.81 (1.37-2.39), or 0.29 (0.18-0.46) associated with each 10-unit increase in alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBIL), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total protein (TP), or albumin (ALB), respectively. Individuals with unhealthy sleep and high (≥ median) ALT, AST, TBIL, GGT, ALP, or TP or low (< median) ALB level had the highest HR of 3.65 (2.43-5.48), 4.03 (2.69-6.03), 1.97 (1.40-2.77), 4.69 (2.98-7.37), 2.51 (1.75-3.59), 2.09 (1.51-2.89), or 2.22 (1.55-3.17) for liver cancer, respectively. Significant additive interaction of unhealthy sleep with high TP level on liver cancer was observed with relative excess risk due to an interaction of 0.80 (0.19-1.41). CONCLUSIONS: Unhealthy sleep was associated with an increased risk of liver cancer, especially in participants with lower ALB levels or higher levels of ALT, AST, TBIL, GGT, ALP, or particularly TP.

Surgical treatment of epileptic encephalopathy with spike-and-wave activation in sleep: A systematic review and meta-analysis.

OBJECTIVE: Epileptic Encephalopathy / Developmental Epileptic Encephalopathy with spike-and-wave activation during sleep (EE/DEE-SWAS) is a self-limiting childhood epilepsy syndrome but may cause permanent neurocognitive impairment. Surgical interventions have been controversial in the treatment of EE/DEE-SWAS. This systematic review aims to evaluate the efficacy of various surgical procedures on the outcomes of EE/DEE-SWAS. METHODS: A systematic review was performed per the PRISMA guidelines. A total of 14 retrospective studies were identified, comprising 131 cases of EE/DEE-SWAS treated with epilepsy surgery. The review analyzed presurgical data, surgical interventions, as well as outcomes related to seizures, EEG, and neuropsychological assessments. RESULTS: Epilepsy surgery was successfully performed in 131 cases with minor complications. The average age was 2.6 years at seizure onset and 5.0 years at diagnosis of SWAS. Excellent seizure control (Engel I and II) was achieved in 80.6 %, 78.6 %, 77.4 % and 27.2 % of patients receiving hemispherectomies, focal resections, multiple subpial transections (MSTs), and corpus callosotomies (CCTs), respectively. EEG SWAS resolution was seen in 79.7 % of hemispherectomy cases, 78.6 % in focal resections, 63.9 % in MSTs, and 8.3 % in CCTs. Neurocognitive and behavioral improvement was noted in 58.0 %, 71.4 %, 58.3 % and 16.7 % for patients receiving hemispherectomies, focal resections, MSTs, and CCTs, respectively. A correlation between improved seizure control and SWAS resolution was observed with improved neuropsychological outcomes. CONCLUSION: Epilepsy surgery is a safe and effective treatment for carefully selected children with drug-resistant EE/DEE-SWAS. Patients who underwent epilepsy surgery had reduction of seizure burden, SWAS resolution and improvements in neurocognitive and behavioral function.

The impact of modifiable lifestyle factors on women's fertility.

The current study centred on assessing the effect of various lifestyle factors (diet, physical activity [PA] level, sleep pattern, and stress level) on women's fertility. This hospitalbased comparative study was conducted at the Avicenna Medical College and Hospital, Lahore, Pakistan, with 104 females (aged 18-40 years) as participants. Half the participants had a history of infertility and 51.8% had a BMI >25. About 43% and 85% reported intake of "junk food" and "fruit and vegetable (F&V)", respectively, twice a week. DASS-21 scale endorsed "moderate-to-high-stress" in 58% of the participants. Further, moderate and intense PAable was documented in 30% and 20% of the participants. About 37% reported sleeping for ≤5 hours/day. Fertility was significantly but inversely correlated with F&V intake, stress level, and BMI. Less sleep and a sedentary lifestyle had a significantly detrimental impact on fertility. Women's fertility was positively impacted by F&V intake, moderate PA, and adequate sleep but negatively impacted by obesity and mental stress.

Causality between sleep traits and the risk of frailty: a Mendelian randomization study.

Background: Research based on observation has demonstrated a relationship between sleep traits and frailty; however, it remains uncertain if this correlation indicates causation. The purpose of this study was to look at the causal relationship that exists between frailty and sleep traits. Method: Using summaries from a genome-wide association study of self-reported sleep features and frailty index, we performed a bidirectional Mendelian randomization (MR) analysis. Examining the causal relationships between seven sleep-related traits and frailty was the goal. The major method used to calculate effect estimates was the inverse-variance weighted method, supplemented by the weighted median and MR-Egger approaches. The study investigated pleiotropy and heterogeneity using several methodologies, such as the MR-Egger intercept, the MR-PRESSO approach, and the Cochran's Q test. We took multivariate Mendelian randomization and genetic correlations between related traits to enhance the confidence of the results. Furthermore, we used MRlap to correct for any estimation bias due to sample overlap. Results: Insomnia, napping during the day, and sleep apnea syndrome exhibited a positive connection with the frailty index in forward MR analysis. Conversely, there is a negative link between getting up in the morning, snoring and sleep duration with the frailty index. During the reverse MR analysis, the frailty index exhibited a positive correlation with insomnia, napping during the day, and sleep apnea syndrome, while demonstrating a negative correlation with sleep duration. There was no direct correlation between snoring, chronotype, and frailty. In MVMR analyses, the causal effect of sleep characteristics on frailty indices remained consistent after adjusting for potential confounders including BMI, smoking, and triglycerides. Conclusion: The findings of our investigation yield novel evidence that substantiates the notion of a bidirectional causal connection between sleep traits and frailty. Through the optimization of sleep, it is potentially feasible to hinder, postpone, or even reverse the state of frailty, and we proposed relevant interventions.

Single-nucleus RNA-seq identifies one galanin neuronal subtype in mouse preoptic hypothalamus activated during recovery from sleep deprivation.

The preoptic area of the hypothalamus (POA) is essential for sleep regulation. However, the cellular makeup of the POA is heterogeneous, and the molecular identities of the sleep-promoting cells remain elusive. To address this question, this study compares mice during recovery sleep following sleep deprivation to mice allowed extended sleep. Single-nucleus RNA sequencing (single-nucleus RNA-seq) identifies one galanin inhibitory neuronal subtype that shows upregulation of rapid and delayed activity-regulated genes during recovery sleep. This cell type expresses higher levels of growth hormone receptor and lower levels of estrogen receptor compared to other galanin subtypes. single-nucleus RNA-seq also reveals cell-type-specific upregulation of purinergic receptor (P2ry14) and serotonin receptor (Htr2a) during recovery sleep in this neuronal subtype, suggesting possible mechanisms for sleep regulation. Studies with RNAscope validate the single-nucleus RNA-seq findings. Thus, the combined use of single-nucleus RNA-seq and activity-regulated genes identifies a neuronal subtype functionally involved in sleep regulation.

Biomathematical modeling of fatigue due to sleep inertia.

Biomathematical models of fatigue capture the physiology of sleep/wake regulation and circadian rhythmicity to predict changes in neurobehavioral functioning over time. We used a biomathematical model of fatigue linked to the adenosinergic neuromodulator/receptor system in the brain as a framework to predict sleep inertia, that is, the transient neurobehavioral impairment experienced immediately after awakening. Based on evidence of an adenosinergic basis for sleep inertia, we expanded the biomathematical model with novel differential equations to predict the propensity for sleep inertia during sleep and its manifestation after awakening. Using datasets from large laboratory studies of sleep loss and circadian misalignment, we calibrated the model by fitting just two new parameters and then validated the model's predictions against independent data. The expanded model was found to predict the magnitude and time course of sleep inertia with generally high accuracy. Analysis of the model's dynamics revealed a bifurcation in the predicted manifestation of sleep inertia in sustained sleep restriction paradigms, which reflects the observed escalation of the magnitude of sleep inertia in scenarios with sleep restriction to less than âˆ¼ 4 h per day. Another emergent property of the model involves a rapid increase in the predicted propensity for sleep inertia in the early part of sleep followed by a gradual decline in the later part of the sleep period, which matches what would be expected based on the adenosinergic regulation of non-rapid eye movement (NREM) sleep and its known influence on sleep inertia. These dynamic behaviors provide confidence in the validity of our approach and underscore the predictive potential of the model. The expanded model provides a useful tool for predicting sleep inertia and managing impairment in 24/7 settings where people may need to perform critical tasks immediately after awakening, such as on-demand operations in safety and security, emergency response, and health care.

Sleep pressure modulates single-neuron synapse number in zebrafish.

Sleep is a nearly universal behaviour with unclear functions1. The synaptic homeostasis hypothesis proposes that sleep is required to renormalize the increases in synaptic number and strength that occur during wakefulness2. Some studies examining either large neuronal populations3 or small patches of dendrites4 have found evidence consistent with the synaptic homeostasis hypothesis, but whether sleep merely functions as a permissive state or actively promotes synaptic downregulation at the scale of whole neurons is unclear. Here, by repeatedly imaging all excitatory synapses on single neurons across sleep-wake states of zebrafish larvae, we show that synapses are gained during periods of wake (either spontaneous or forced) and lost during sleep in a neuron-subtype-dependent manner. However, synapse loss is greatest during sleep associated with high sleep pressure after prolonged wakefulness, and lowest in the latter half of an undisrupted night. Conversely, sleep induced pharmacologically during periods of low sleep pressure is insufficient to trigger synapse loss unless adenosine levels are boosted while noradrenergic tone is inhibited. We conclude that sleep-dependent synapse loss is regulated by sleep pressure at the level of the single neuron and that not all sleep periods are equally capable of fulfilling the functions of synaptic homeostasis.

Sleep hygiene - What do we mean? A bibliographic review.

There is no consensus on the definition of sleep hygiene and its components. We examined the definition of sleep hygiene based on its use in published studies. Four databases (Medline, EMBASE, PsycINFO and CINAHL) were searched from inception until December 31, 2021 for the phrase 'sleep hygiene' in the title or abstract. We identified 548 relevant studies in adults: 250 observational and 298 intervention studies. A definition of sleep hygiene was provided in only 44% of studies and converged on three themes: behavioural factors, environmental factors, and an aspect of control. Sleep hygiene components were explicitly defined in up to 70% of observational studies, but in only 35% of intervention studies. The most commonly considered components of sleep hygiene were caffeine (in 51% of studies), alcohol (46%), exercise (46%), sleep timing (45%), light (42%), napping (39%), smoking (38%), noise (37%), temperature (34%), wind-down routine (33%), stress (32%), and stimulus control (32%), although the specific details of each component varied. Lack of consistency in definitions of sleep hygiene and its components may hinder communication between researchers, clinicians, and the public, and likely limits the utility of sleep hygiene as an intervention.