Aging-related sleep changes

A game-based learning approach to sleep hygiene education: a pilot investigation

Introduction

Sleep hygiene education (SHE) consists of environmental and behavioral practices primarily intended to reduce sleep problems. Currently considered ineffective as a stand-alone treatment, the manner in which the education is typically delivered may be ineffective for the acquisition of new knowledge. The purpose of this study was to determine if a more engaging teaching medium may improve the efficacy of sleep hygiene education. This study examined the use of game-based learning to teach SHE to individuals with sleep problems.

Methods

35 participants played the SHE games for 30 days. Differences in pre- and post-state anxiety and sleep quality measures were examined.

Results

Participants had significant improvements in sleep quality and state anxiety after using the app for 30 days, although scores for the majority of patients remained elevated.

Discussion

This pilot investigation provides initial evidence for the efficacy of a game-based approach to SHE.

Actigraphy Estimated Sleep Moderates the Relationship between Physical Activity and Cognition in Older Adults

Background and Aims

Physical inactivity and poor sleep are common in older adults and may interact to contribute to age- and disease-related cognitive decline. However, prior work regarding the associations among physical activity, and cognition in older adults is primarily limited to subjective questionnaires that are susceptible to inaccuracies and recall bias. Therefore, this study examined whether objectively measured physical activity and sleep characteristics, each estimated using actigraphy, are independently or interactively associated with cognitive performance.

Methods

The study included 157 older adults free of dementia (136 cognitively unimpaired; 21 MCI; M age = 71.7) from the BIOCARD cohort.

Results

Using multiple linear regression, cognition was regressed on estimated total volume of physical activity (TVPA), sleep efficiency (SE), wake after sleep onset (WASO), and total sleep time (TST) (adjusted for age, sex, education, diagnosis, vascular risk factors, and Apolipoprotein E (APOE)-e4 genetic status). Models were also run for domain-specific cognitive composite scores. TVPA and SE each were positively associated with a global cognitive composite score. TVPA was positively associated with executive function and language composites, and SE was positively related to executive function, visuospatial, and language composites. Importantly, a TVPA by SE interaction (p = 0.015) suggested that adults with the poorest SE experienced the greatest benefit from physical activity in relation to global cognition. The other sleep metrics were unrelated to cognitive performance.

Conclusion

These results suggest that TVPA and SE may synergistically benefit cognition in older adults.

Linking brain structure, cognition, and sleep: insights from clinical data

STUDY OBJECTIVES

To use relatively noisy routinely collected clinical data (brain magnetic resonance imaging (MRI) data, clinical polysomnography (PSG) recordings, and neuropsychological testing), to investigate hypothesis-driven and data-driven relationships between brain physiology, structure, and cognition.

METHODS

We analyzed data from patients with clinical PSG, brain MRI, and neuropsychological evaluations. SynthSeg, a neural network-based tool, provided high-quality segmentations despite noise. A priori hypotheses explored associations between brain function (measured by PSG) and brain structure (measured by MRI). Associations with cognitive scores and dementia status were studied. An exploratory data-driven approach investigated age-structure-physiology-cognition links.

RESULTS

Six hundred and twenty-three patients with sleep PSG and brain MRI data were included in this study; 160 with cognitive evaluations. Three hundred and forty-two participants (55%) were female, and age interquartile range was 52 to 69 years. Thirty-six individuals were diagnosed with dementia, 71 with mild cognitive impairment, and 326 with major depression. One hundred and fifteen individuals were evaluated for insomnia and 138 participants had an apnea-hypopnea index equal to or greater than 15. Total PSG delta power correlated positively with frontal lobe/thalamic volumes, and sleep spindle density with thalamic volume. rapid eye movement (REM) duration and amygdala volume were positively associated with cognition. Patients with dementia showed significant differences in five brain structure volumes. REM duration, spindle, and slow-oscillation features had strong associations with cognition and brain structure volumes. PSG and MRI features in combination predicted chronological age (R2 = 0.67) and cognition (R2 = 0.40).

CONCLUSIONS

Routine clinical data holds extended value in understanding and even clinically using brain-sleep-cognition relationships.

Is poor sleep quality associated with lipid profile in elderly population? Finding from Iranian Longitudinal Study on Ageing

BACKGROUND

Abnormal lipid profile as one of reversible cardiovascular disease risk factors might be affected by poor sleep quality.

AIM

This study aimed to assess the association between poor sleep quality and serum concentration of lipid profile in Iranian elderly population.

METHODS

The study was performed on a representative sample of 3452 Iranian older people (≥60 years) who contributed in the Iranian Longitudinal Study on Ageing (IRLSA). Sleep quality was measured through the validated Persian version of Pittsburgh Sleep Quality Index (PSQI). Fasting blood samples were collected from the participants to measure plasma levels lipid profile. We used multiple linear regression model to evaluate the independent association of poor sleep quality with lipid profile.

RESULTS

The mean age of participants was 68.0±6.7 years and 52.5% of them were male. In total, 52.4% of study population reported poor sleep quality (PSQI>5). Mean serum concentration of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) was 143.2±74.2 mg/dl, 195.6±43.2 mg/dl, 112.9±31.0 mg/dl, and 57.3±12.4 mg/dl, respectively. Poor sleep quality was significantly associated with serum levels of TG (β=17.85; P=0.006), LDL-C (β=5.45; P=0.039) and HDL-C (β=-2.13; P=0.039) after adjusting for studied covariates.

CONCLUSION

Our study illustrates that poor sleep quality is a risk factor for poorer lipid profile. Therefore, early behavioral or pharmacological interventions that improve sleep quality are necessary to modify lipid profile in elderly population.

[Changes the level of differentiating growth factor - GDF 15 in patients with sleep apnea syndrome after aPAP-therapy: pilot study]

OBJECTIVE

Comparative assessment of the level of differentiating growth factor 15 (GDF 15 ) against the background of a 6-month course of respiratory support in the mode of automatic positive pressure in the airways therapy (aPAP therapy) in patients with obstructive sleep apnea syndrome (OSA).

MATERIAL AND METHODS

59 men participated in the study, the average age was 51.9±2.4 years. The main group (MG1) consisted of 30 patients with a verified diagnosis of moderate OSA. 29 men of comparable age and body weight made up the control group (CG) without an objectively confirmed diagnosis of OSA. After the stage of introduction into the study, the type of respiratory support with individual pressure settings was selected for patients with MG1. After 6 months of aPAP therapy with high compliance (at least 85%), the same patients who made up MG2 after treatment underwent repeated polysomnography (PSG) and the GDF 15 content was evaluated. Methods: questionnaire, examination, polysomnography, enzyme immunoassay of blood serum to determine the content of GDF 15.

RESULTS

A 6-month course of aPAP therapy with a high degree of compliance significantly improved the sleep structure and breathing pattern: the representation of NREM 3 increased from 79.2±15.6 to 102.6±21.6 minutes and the REM phase from 56.9± 13.6 to 115.6±26.8. Episodes of apnea were eliminated - apnea-hypopnea index decreased from 21.1 [17.3; 39.1] to 2.5 [1.8; 4.6] and the average values of SaO2 increased from 85.9% to 91.5%. At the same time, a statistically significant excess of GDF 15 was revealed in MG1 - 20.4 [14.16; 31.71] and MG2 - 17.2 [13.63; 24.44]) in comparison with CG - 13.65 [10.7; 17.09]. Despite the lack of statistical significance, a change in the level of GDF 15 was revealed in the form of a decrease in its concentration after a 6-month course of aPAP therapy.

CONCLUSION

A 6-month course of aPAP therapy made it possible to eliminate intermittent nocturnal hypoxia and improve sleep structure in patients with OSA, as well as reduce the content of GDF 15 protein in blood serum in patients with OSA. However, the tendency to decrease the content of this protein, despite the lack of statistical reliability, confirms the effectiveness of OSA therapy and the possibility of preventing early and pathological aging from the standpoint of somnology and molecular biogerontology.

Racial and Ethnic Trajectories of Sleep Disturbances: Variations by Age and Cohort

BACKGROUND

The racial and ethnic differences in trajectories of sleep disturbances in later life are crucial for addressing health disparities, but are not well understood. This study examines (a) how trajectories of sleep disturbances vary by race and ethnicity and birth cohort and (b) whether social and health risk factors explain such variations.

METHODS

The study uses longitudinal data from the 2002-2018 Health and Retirement Study (N = 21 963) and the multilevel growth curve model to assess trajectories of sleep disturbances and their variations across 6 cohorts of White, Black, and Hispanic older adults. Sleep disturbances are measured using a modified Jenkins Sleep Scale.

RESULTS

Without controls, sleep disturbances increased with aging for all racial and ethnic groups, but more rapidly among minorities, particularly younger cohorts of Hispanic older adults. When controlling for social and health risks, sleep disturbances did not change with aging for Whites and Blacks and increased for younger cohorts of Hispanics. Cohort effects were observed among White older adults, with higher sleep disturbances in younger cohorts. Importantly, the racial and ethnic disparities in age and cohort effects were not fully explained by social and health risks. Of the symptoms, the most salient racial and ethnic disparities were found in "waking up at night" and "not feeling rested."

CONCLUSIONS

Findings reveal several differences by race and ethnicity and birth cohort in trajectories of sleep disturbances. Efforts should be made to improve sleep health for older adults as they age, especially for younger cohorts of Blacks and Hispanics.

The relationship between oral health and sleep quality in community-dwelling older adults

Introduction

The assessment of the sleep status of older adults and its relationship to oral health can help determine their well-being and quality of life. In accordance with this purpose, we aimed to evaluate the relationship between oral health and sleep quality in community-dwelling older adults in an urban area.

Materials and Methods

The data of this study were taken from the Kayseri Elderly Health Study. The study group was administered a questionnaire form and the Pittsburgh Sleep Quality Index. A specialist dentist examined the oral health conditions (dentures use; caries; deficient, filled, natural teeth numbers; periodontal health) using the Community Periodontal Index and the Oral Health Impact Profile-14 (OHIP-14-TR).

Results

One hundred forty (38.1%) of the study group were female, and 227 (61.9%) were male. When evaluated in terms of oral hygiene, there was a statistically significant difference between those with good sleep quality and poor sleep quality in terms of mechanical interventions such as using toothpaste and an inter-dental brush, and also, OHIP-14-TR was significant. In the binary logistic regression analysis, OHIP-14-TR was found to be a significant risk factor, reflecting only the subjective interpretation of the older adults in terms of oral health-related quality of life (odds ratio: 1.069, 95.0% confidence interval: 1.043-1.096).

Conclusion

This is the first epidemiologic study to examine the relationship between oral health status and sleep quality, in which many oral health indicators are evaluated together in Turkish community-dwelling older adults. OHIP-14-TR may be a useful tool to employ in sleep disorder clinics for older people.

The impact of sleep disturbance on pain perception: A systematic review examining the moderating effect of sex and age

Females have increased pain sensitivity and are more vulnerable to chronic pain conditions. Sleep disturbances are comorbid with chronic pain and exacerbate pain symptoms. Different types of sleep disturbance affect pain perception distinctly, but it is not clear if these effects are equal in men and women. This systematic review investigated potential differences in how sleep disturbance affects pain in males and females. We searched EBSCO, MEDLINE, Psych INFO, Science Direct, and Web of Science from January 2001 to November 2022 and found 38 studies with 978 participants. Separate random-effects models were used to estimate the pooled effect sizes based on standardized mean differences (SMDs) of experimental sleep disturbance paradigms on various pain outcomes. Sex moderated the effect of sleep disturbance on pain facilitation (SMD = 0.13; 95%CI: 0.004 to 0.022; p=.009) and pain inhibition (SMD = 0.033; 95%CI: 0.011 to 0.054; p=.005), with increased facilitation and decreased inhibition in females, but the opposite effect in males. Further, age moderated the effects of total sleep deprivation (SMD = -0.194; 95%CI -0.328 to -0.060; p=.008) on pain sensitivity and fragmented sleep (SMD = -0.110; 95%CI: 0.148 to -0.072; p<.001) on pain threshold. While the moderating effect of sex and age on the sleep-pain relationship was small, these factors need to be considered in future sleep-pain research.

The association between sleep duration and risk of myopia in Chinese school-aged children: a cross-sectional study

BACKGROUND

Myopia is one of the most commonly diagnosed refractive disorders worldwide. Identifying risk factors for myopia at an early age may help to characterize children who would benefit most from individualized lifestyle advice and early interventions. The influence of sleep duration on myopia risk remains controversial and thus needs to be evaluated.

METHODS

A population-based cross-sectional study of Chinese school-aged children was conducted. Information on sleep duration was derived. The association between sleep duration and myopia risk was investigated by logistic regression analysis.

RESULTS

Myopia prevalence among 9530 Chinese school-aged children was 75.4% and decreased from 84.9%, 76.5%, 65.8%, to 61.3% along with the extension of sleep duration. Univariate logistic regression found longer sleep duration of 8-9 h (OR = 0.58, 95% CI: 0.51-0.66), 9-10 h (OR = 0.34, 95% CI: 0.30-0.39), and ≥ 10 h (OR = 0.28, 95% CI: 0.24-0.33) were protective factors for myopia in all participants (P for trend < 0.001). In the multivariate analyses, sleep duration was inversely associated with the risk of myopia, and a dose-effect relationship was observed when the analysis was split by age category.

CONCLUSIONS

Long sleep duration was associated with decreased risk of myopia in Chinese school-aged children.

Rapid eye movement sleep loss associated cytomorphometric changes and neurodegeneration

Rapid eye movement sleep (REMS) is essential for leading normal healthy living at least in higher-order mammals, including humans. In this review, we briefly survey the available literature for evidence linking cytomorphometric changes in the brain due to loss of REMS. As a mechanism of action, we add evidence that REMS loss elevates noradrenaline (NA) levels in the brain, which affects neuronal cytomorphology. These changes may be a compensatory mechanism as the changes return to normal after the subjects recover from the loss of REMS or if during REMS deprivation, the subjects are treated with NA-adrenoceptor antagonist prazosin (PRZ). We had proposed earlier that one of the fundamental functions of REMS is to maintain the level of NA in the brain. We elaborate on this idea to propose that if REMS loss continues without recovery, the sustained level of NA breaks down neurophysiologically active compensatory mechanism/s starting with changes in the neuronal cytomorphology, followed by their degeneration, leading to acute and chronic pathological conditions. Identification of neuronal cytomorphological changes could prove to be of significance for predicting future neuronal (brain) damage as well as an indicator for REMS health. Although current brain imaging techniques may not enable us to visualize changes in neuronal cytomorphology, given the rapid technological progress including use of artificial intelligence, we are optimistic that it may be a reality soon. Finally, we propose that maintenance of optimum REMS must be considered a criterion for leading a healthy life.

Racial and Ethnic Differences in Sleep Duration Life Expectancies among Men and Women in Mid-to-Late Life

This analysis documents U.S. racial/ethnic and gender differences in life expectancies with different self-reported sleep durations among adults aged 50 and older. We used self-reported sleep duration and linked mortality information from the 2004-2015 National Health Interview Survey (n = 145,015) to calculate Sullivan Method Lifetables for life expectancies with different self-reported sleep duration states: short (≤6 hours), optimal (seven to 8 hours), and long (≥9 hours) sleep duration per-day by race/ethnicity and gender. Non-Hispanic Black men (35.8%, 95% CI: 34.8%-36.8%) and women (36.5%, 95% CI: 35.7%-37.1%) exhibited the highest proportion of years lived with short sleep duration followed by Hispanic men (31.1%, 95% CI: 29.9%-32.3%) and women (34.1%, 95% CI: 33.1%-35.1%) and Non-Hispanic White men (25.8%, 95% CI: 25.4%-26.2%) and women (27.4%, 95% CI: 27.0%-27.7%). These results highlight how race/ethnic inequality in sleep duration and life expectancy are intertwined among older adults in the U.S.

Longitudinal patterns of lifestyle risk behaviours among UK adults with established cardiovascular disease: a latent transition analysis

Background

People with cardiovascular disease (CVD) need to engage in healthy lifestyle behaviours. However, there is a gap in identifying longitudinal patterns of change in lifestyle behaviours among people with CVD. This study aimed to identify clustering of lifestyle risk behaviours and their 4 ± year changes among UK adults with CVD, and to determine the associated factors.

Methods

We used the UK Biobank data collected at two time points (2006-2010/baseline data = T0 and 2014+/third visit data = T4). Six key lifestyle risk behaviours were assessed: smoking, high alcohol intake, poor fruit and vegetable consumption, physical inactivity, poor sleep balance (<7 or >8 h/night) and prolonged sitting. A random intercept latent transition analysis was performed to identify patterns of lifestyle risk behaviours at T0 and their changes from T0 to T4.

Results

We included 5,304 participants with CVD whose data on lifestyle risk behaviours were collected at two-time points. Alcohol intake and current smoking were 75.7% and 5.4% at baseline, respectively, and 67.4% and 3.0% at follow-up. Three latent classes emerged: Latent class (LC) 1-"high alcohol intake, poor sleep balance and poor fruit and vegetable intake", LC2-"high alcohol intake and poor fruit and vegetable intake", and LC3-"high alcohol intake". Most adults remained in the same LC over the 4 + years (range: 83.9%-100.0%). After 4 + years, 3.5% from LC3 and 10.4% from LC2 at baseline moved into LC1. The odds of transitioning to LC2 relative to staying in LC1 and LC3 were 2.22 and 4.13 times higher for males than for females, respectively. A single-year increase in participants' age was associated with a 1.16 times increase in the odds of moving to LC1 relative to staying in LC2.

Conclusion

People with CVD did not show improvement in lifestyle risk behaviours, and interventions targeting multiple lifestyle risk behaviours are needed to improve CVD.

Deriving Multiple-Layer Information from a Motion-Sensing Mattress for Precision Care

Bed is often the personal care unit in hospitals, nursing homes, and individuals' homes. Rich care-related information can be derived from the sensing data from bed. Patient fall is a significant issue in hospitals, many of which are related to getting in and/or out of bed. To prevent bed falls, a motion-sensing mattress was developed for bed-exit detection. A machine learning algorithm deployed on the chip in the control box of the mattress identified the in-bed postures based on the on/off pressure pattern of 30 sensing areas to capture the users' bed-exit intention. This study aimed to explore how sleep-related data derived from the on/off status of 30 sensing areas of this motion-sensing mattress can be used for multiple layers of precision care information, including wellbeing status on the dashboard and big data analysis for living pattern clustering. This study describes how multiple layers of personalized care-related information are further derived from the motion-sensing mattress, including real-time in-bed/off-bed status, daily records, sleep quality, prolonged pressure areas, and long-term living patterns. Twenty-four mattresses and the smart mattress care system (SMCS) were installed in a dementia nursing home in Taiwan for a field trial. Residents' on-bed/off-bed data were collected for 12 weeks from August to October 2021. The SMCS was developed to display care-related information via an integrated dashboard as well as sending reminders to caregivers when detecting events such as bed exits and changes in patients' sleep and living patterns. The ultimate goal is to support caregivers with precision care, reduce their care burden, and increase the quality of care. At the end of the field trial, we interviewed four caregivers for their subjective opinions about whether and how the SMCS helped their work. The caregivers' main responses included that the SMCS helped caregivers notice the abnormal situation for people with dementia, communicate with family members of the residents, confirm medication adjustments, and whether the standard care procedure was appropriately conducted. Future studies are suggested to focus on integrated care strategy recommendations based on users' personalized sleep-related data.

Fatigue and Sleep in Airline Cabin Crew: A Scoping Review

Airline cabin crew operate in dynamic work environments that are continuously changing, from unpredictable shift work hours to travelling through multiple time zones. These likely impact cabin crews' overall health and may affect their performance on safety-related tasks. Research on this population has been limited; therefore, the aim was to summarise the relevant literature regarding fatigue, sleepiness and mental health of cabin crew. This review followed the PRISMA-ScR guidelines and conducted a systematic search utilising five databases. The initial search identified 1223 studies, and through vigorous screening processes, 27 studies were selected for this review. Over half of the selected studies focused on international or long-haul flights, and a large proportion of the sample participants were women. Findings suggested a high prevalence of fatigue and sleepiness as well as unsatisfactory sleep quality with elevated susceptibility to sleep disorders. Factors identified with health outcomes were associated with flight operations (e.g., rosters) and individual differences (e.g., age and coping strategies). Regarding mental health, cabin crews are potentially at a greater risk for depression and anxiety compared to the general public. This review draws attention to the importance of using a standardised approach, such as validated measures for fair and consistent inferences.

Poor Sleep Quality in Aging: The Association with Mental Health

Sleep disturbances are common in the elderly. A primary sleep disorder can result from the physiological decline of aging; however, secondary sleep problems result from various causes involving physical and mental health. Since little is known about the relationships between sleep quality and mental health in aging, the present study aims to understand how different aspects generally associated with sleep (e.g., psychological and physiological factors, and sleep medication) may predict poor sleep quality in different stages of the lifespan. Therefore, we conducted several analyses (ANOVAs, Pearson correlations, and linear regressions) to test the hypotheses of the study. Accordingly, from a pool of 180 participants (elderly, middle-aged, and young adults), 143 individuals with poor sleep quality were selected. Different predictive patterns in the three groups emerged. Specifically, the use of sleep medication associated with worse sleep conditions is predicted by poor sleep quality in the elderly and by depression in young adults. In contrast, worsening sleep quality is predicted by depression in middle-aged adults. Previous studies focused on the transitions from good to poor sleep quality, while this is the first study to have examined the features of poor sleep quality in aging, highlighting different sleep patterns across the lifespan. This evidence should be considered from a preventive perspective.

Is Cognitive Behavioral Therapy for Insomnia Effective for Improving Sleep Duration in Individuals with Insomnia? A Meta-Analysis of Randomized Controlled Trials

Background

Accumulating evidence suggests that sleep duration is a critical determinant of physical and mental health. Half of the individuals with chronic insomnia report less than optimal sleep duration. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment for reducing sleep difficulties in individuals with chronic insomnia. However, its effectiveness for increasing sleep duration is less well-established and a synthesis of these findings is lacking.

Purpose

To provide a synthesis of findings from randomized controlled trials (RCTs) on the effect of CBT-I on subjective and objective total sleep time (TST).

Methods

A systematic search was performed on articles published from 2004 to 05/30/2021. A total of 43 RCTs were included in the meta-analysis. Publication biases were examined. Meta-regressions were conducted to examine if any sample or treatment characteristics moderated the effect sizes across trials.

Results

We found a small average effect of CBT-I on diary-assessed TST at post-treatment, equivalent to an approximately 30-min increase. Age significantly moderated the effects of CBT-I on diary-measured and polysomnography-measured TST; older ages were associated with smaller effect sizes. Contrarily, a negative, medium effect size was found for actigraphy-assessed TST, equivalent to an approximately 30-min decrease. Publication biases were found for diary data at follow-up assessments suggesting that positive findings were favored.

Conclusions

CBT-I resulted in improvements in TST measured by sleep diaries and polysomnography (in adults). These improvements were not corroborated by actigraphy findings. Theoretical and clinical implications were discussed.

Experimental study of the negative effects of raised bedroom temperature and reduced ventilation on the sleep quality of elderly subjects

This study investigated the effects of air temperature and ventilation on the sleep quality of elderly subjects and elucidated the mechanisms involved. Sixteen subjects aged over 65 years old were exposed to four conditions in a 2 × 2 design: air temperatures of 27°C and 30°C (with a ceiling fan in operation at 30°C) and two ventilation conditions (with and without mechanical ventilation) in experimental bedrooms. Their electroencephalogram, electrooculogram, chin electromyogram, electrocardiogram, respiration, oxygen saturation, and wrist skin temperature were measured continuously during sleep. Saliva samples were collected, and blood pressure was measured both before and after sleep. The results showed that at the temperature of 30°C, the total sleep time, sleep efficiency, and duration of REM sleep of the elderly decreased by 26.3 min, 5.5%, and 5.3 min, respectively, and time awake increased by 27.0 min, in comparison with 27°C, indicating that the sleep quality of the elderly is very vulnerable to heat exposure. Even a small heat load led to an overactive sympathetic nervous system and increased wrist skin temperature, which reduced sleep quality. Improving the ventilation increased the duration of deep sleep and REM sleep by 10.3 min and 3.7 min, respectively. Higher pollutant concentrations affected the respiration and autonomous nervous systems to reduce sleep quality. The benefits of improved thermal environment and ventilation on sleep quality were found to be additive. Good ventilation and the avoidance of raised temperatures in the bedroom are thus both important for the sleep quality of the elderly.

Associations of testosterone and cortisol concentrations with sleep quality in Japanese male workers

Low testosterone concentrations are associated with disrupted sleep, and high levels of cortisol, which is elevated in response to stress, lead to insomnia. This study aimed to investigate the associations of testosterone and cortisol concentrations with sleep quality and to examine potential interactions between them in Japanese working men. This study was a cross-sectional design, and testosterone and cortisol concentrations in blood were the exposure variables and sleep parameters were the outcome variables. The Japanese version of the Pittsburgh Sleep Quality Index was used to measure sleep quality, and it included the total duration of sleep, time in bed (TIB), and sleep efficacy. We included 178 men (mean age = 49.1 years, standard deviation = 9.0) who completed all components in the questionnaire related to sleep and provided blood samples. Testosterone and cortisol concentrations were negatively associated with TIB (standardized beta = −0.15 and −0.24, p < 0.05, respectively), while only testosterone concentrations were positively associated with sleep efficacy (standardized beta = 0.15, p < 0.05). An interaction effect of testosterone and cortisol was significant for TIB and sleep efficacy (standardized beta for interaction term = 0.40, p < 0.001 and −0.22, p = 0.012, respectively). When stratified by cortisol concentrations, the associations between testosterone concentrations and sleep parameters were modified. Our findings suggest that associations between testosterone concentrations and sleep parameters are stronger at low cortisol concentrations, but not at high cortisol concentrations. High cortisol concentrations may diminish associations between low testosterone concentrations and diminished sleep efficacy.

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Testosterone and cortisol levels were negatively associated with hours in bed.

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Testosterone concentrations were positively associated with sleep efficacy.

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Cortisol levels modified the associations between testosterone and sleep efficacy.

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Testosterone strongly associated with sleep efficacy in low cortisol levels.

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Cortisol levels may inhibit associations between testosterone and sleep efficacy.

Effect of Docosahexaenoic Acid and Eicosapentaenoic Acid Supplementation on Sleep Quality in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Trial

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-omega-3 fatty acids with various functions-influence sleep in children and young adults. However, only limited studies on their effects on sleep in middle- and old-aged adults have been reported. Therefore, we investigated the effects of DHA and EPA on sleep quality in subjects aged ≥ 45 years. We performed a randomized, placebo-controlled, double-blinded, parallel-grouped study, in which we randomly assigned 66 healthy Japanese males and females. Each individual received six 480 mg capsules containing 576 mg DHA and 284 mg EPA per day (DHA/EPA group, n = 33), or corn oil (placebo group, n = 33), for 12 weeks. Before and after the intervention, the Oguri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) and the sleep state test were conducted. In the DHA/EPA group, factor III (frequent dreaming) scores among the OSA-MA scores were significantly improved compared to the placebo group. Additionally, sleep state tests revealed that sleep efficiency improved in the DHA/EPA group. To our knowledge, this study is the first to report that DHA/EPA improves sleep quality in middle- and old-aged individuals, even at doses lower than those administered in previous studies.

The associations of BMI, chronic conditions and lifestyle factors with insomnia symptoms among older adults in India

Background

The aim of the study was to estimate the prevalence of insomnia symptoms and to examine the associations of body mass index (BMI), chronic diseases, and lifestyle factors with self-reported insomnia symptoms among older people in India.

Methods

We conducted a cross-sectional study using data from the baseline wave of the Longitudinal Ageing Study in India (LASI) that was collected during 2017–18. A sample of 31,358 older adults aged 60 and above was included in the analyses. Descriptive statistics and bivariate and multivariable analyses were performed to obtain the results.

Results

In this study, insomnia symptoms were reported by around 36 percent of older adults aged 60 and above. After controlling for socio-demographic factors, insomnia symptoms were positively associated with the risk of being underweight [AOR: 1.289, CI: 1.211–1.372] and negatively associated with obesity/overweight [AOR: 0.928, CI: 0.872–0.990] as compared to older adults with normal BMI. The odds of insomnia symptoms were higher among those who reported the following chronic conditions, i.e., hypertension [AOR:1.356, CI:1.278–1.438], diabetes [AOR:1.160, CI:1.074–1.254], chronic lung diseases [AOR:1.485, CI:1.351–1.632], bone-related diseases [AOR:1.561, CI:1.458–1.670] and any psychiatric disorders [AOR:1.761, CI:1.495–2.074]. In addition, older adults who were physically active [AOR: 0.850, CI:0.804–0.900] were less likely to report insomnia symptoms.

Conclusions

The study suggests a high prevalence of insomnia symptoms among the older population in India. Early identification of the signs of insomnia in older population is crucial, as is timely treatment for any kind of sleep problems. In addition, nutrition-based interventions and individual disease-specific management programs may help minimize the stressful situations in later life and develop a good night’s sleep for the older population.

Sleep Quality and Aging: A Systematic Review on Healthy Older People, Mild Cognitive Impairment and Alzheimer’s Disease

Aging is characterized by changes in the structure and quality of sleep. When the alterations in sleep become substantial, they can generate or accelerate cognitive decline, even in the absence of overt pathology. In fact, impaired sleep represents one of the earliest symptoms of Alzheimer’s disease (AD). This systematic review aimed to analyze the studies on sleep quality in aging, also considering mild cognitive impairment (MCI) and AD. The review process was conducted according to the PRISMA statement. A total of 71 studies were included, and the whole sample had a mean age that ranged from 58.3 to 93.7 years (62.8–93.7 healthy participants and 61.8–86.7 pathological populations). Of these selected studies, 33 adopt subjective measurements, 31 adopt objective measures, and 10 studies used both. Pathological aging showed a worse impoverishment of sleep than older adults, in both subjective and objective measurements. The most common aspect compromised in AD and MCI were REM sleep, sleep efficiency, sleep latency, and sleep duration. These results underline that sleep alterations are associated with cognitive impairment. In conclusion, the frequency and severity of sleep disturbance appear to follow the evolution of cognitive impairment. The overall results of objective measures seem more consistent than those highlighted by subjective measurements.

Sleep in Normal Aging

Sleep is a key determinant of healthy and cognitive aging. Sleep patterns change with aging, independent of other factors, and include advanced sleep timing, shortened nocturnal sleep duration, increased frequency of daytime naps, increased number of nocturnal awakenings and time spent awake during the night, and decreased slow-wave sleep. The sleep-related hormone secretion changes with aging. Most changes seem to occur between young and middle adulthood; sleep parameters remain largely unchanged among healthy older adults. The circadian system and sleep homeostatic mechanisms become less robust with normal aging. The causes of sleep disturbances in older adults are multifactorial.

An investigation of cannabis use for insomnia in depression and anxiety in a naturalistic sample

BACKGROUND

Little is known about cannabis use for insomnia in individuals with depression, anxiety, and comorbid depression and anxiety. To develop a better understanding of distinct profiles of cannabis use for insomnia management, a retrospective cohort study was conducted on a large naturalistic sample.

METHODS

Data were collected using the medicinal cannabis tracking app, Strainprint®, which allows users to monitor and track cannabis use for therapeutic purposes. The current study examined users managing insomnia symptoms in depression (n = 100), anxiety (n = 463), and comorbid depression and anxiety (n = 114), for a total of 8476 recorded sessions. Inferential analyses used linear mixed effects modeling to examine self-perceived improvement across demographic variables and cannabis product variables.

RESULTS

Overall, cannabis was perceived to be efficacious across all groups, regardless of age and gender. Dried flower and oral oil were reported as the most used and most efficacious product forms. In the depression group, all strains were perceived to be efficacious and comparisons between strains revealed indica-dominant (M_diff = 1.81, 95% CI 1.26-2.36, P_adj < .001), indica hybrid (M_diff = 1.34, 95% CI 0.46-2.22, P_adj = .045), and sativa-dominant (M_diff = 1.83, 95% CI 0.68-2.99, P_adj = .028) strains were significantly more efficacious than CBD-dominant strains. In anxiety and comorbid conditions, all strain categories were perceived to be efficacious with no significant differences between strains.

CONCLUSIONS

In terms of perceptions, individuals with depression, anxiety, and both conditions who use cannabis for insomnia report significant improvements in symptom severity after cannabis use. The current study highlights the need for placebo-controlled trials investigating symptom improvement and the safety of cannabinoids for sleep in individuals with mood and anxiety disorders.

Auditory deep sleep stimulation in older adults at home: a randomized crossover trial

Background

Auditory stimulation has emerged as a promising tool to enhance non-invasively sleep slow waves, deep sleep brain oscillations that are tightly linked to sleep restoration and are diminished with age. While auditory stimulation showed a beneficial effect in lab-based studies, it remains unclear whether this stimulation approach could translate to real-life settings.

Methods

We present a fully remote, randomized, cross-over trial in healthy adults aged 62-78 years (clinicaltrials.gov: NCT03420677). We assessed slow wave activity as the primary outcome and sleep architecture and daily functions, e.g., vigilance and mood as secondary outcomes, after a two-week mobile auditory slow wave stimulation period and a two-week Sham period, interleaved with a two-week washout period. Participants were randomized in terms of which intervention condition will take place first using a blocked design to guarantee balance. Participants and experimenters performing the assessments were blinded to the condition.

Results

Out of 33 enrolled and screened participants, we report data of 16 participants that received identical intervention. We demonstrate a robust and significant enhancement of slow wave activity on the group-level based on two different auditory stimulation approaches with minor effects on sleep architecture and daily functions. We further highlight the existence of pronounced inter- and intra-individual differences in the slow wave response to auditory stimulation and establish predictions thereof.

Conclusions

While slow wave enhancement in healthy older adults is possible in fully remote settings, pronounced inter-individual differences in the response to auditory stimulation exist. Novel personalization solutions are needed to address these differences and our findings will guide future designs to effectively deliver auditory sleep stimulations using wearable technology.

Benchmarking real-time algorithms for in-phase auditory stimulation of low amplitude slow waves with wearable EEG devices during sleep

Auditory stimulation of EEG slow waves (SW) during non-rapid eye movement (NREM) sleep has shown to improve cognitive function when it is delivered at the up-phase of SW. SW enhancement is particularly desirable in subjects with low-amplitude SW such as older adults or patients suffering from neurodegeneration such as Parkinson disease (PD). However, existing algorithms to estimate the up-phase suffer from a poor phase accuracy at low EEG amplitudes and when SW frequencies are not constant. We introduce two novel algorithms for real-time EEG phase estimation on autonomous wearable devices. The algorithms were based on a phase-locked loop (PLL) and, for the first time, a phase vocoder (PV). We compared these phase tracking algorithms with a simple amplitude threshold approach. The optimized algorithms were benchmarked for phase accuracy, the capacity to estimate phase at SW amplitudes between 20 and 60 V, and SW frequencies above 1 Hz on 324 recordings from healthy older adults and PD patients. Furthermore, the algorithms were implemented on a wearable device and the computational efficiency and the performance was evaluated on simulated sleep EEG, as well as prospectively during a recording with a PD patient. All three algorithms delivered more than 70% of the stimulation triggers during the SW up-phase. The PV showed the highest capacity on targeting low-amplitude SW and SW with frequencies above 1 Hz. The testing on real-time hardware revealed that both PV and PLL have marginal impact on microcontroller load, while the efficiency of the PV was 4% lower than the PLL. Active auditory stimulation did not influence the phase tracking. This work demonstrated that phase-accurate auditory stimulation can be delivered during home-based sleep interventions with a wearable device also in populations with low-amplitude SW.

Nonlinear associations between sleep patterns and sarcopenia risks in older adults

STUDY OBJECTIVES

Despite considering it as a common geriatric condition, sarcopenia is linked to various behavioral factors that may be changeable. As sleep is one of the important routines in physiological homeostasis, further investigating the underlying relationships of sleep behavior with sarcopenia is urgently needed. We examined the association between sleep parameters (ie, sleep duration, bedtime, wake time, or midsleep time) and sarcopenia risks in older adults, in the total sample and age group subsamples.

METHODS

A total of 1,068 older adults in Taiwan were included. Data on bedtime, wake time, and sleep duration were collected through telephone interview. Midsleep time was calculated by the midpoint of bedtime and wake time. Sarcopenia was screened by the SARC-F questionnaire composed of 5 questions (the strength, assistance in walking, rising from a chair, climbing stairs, and falls) as well as higher scores was related to greater risks. Generalized additive models were conducted to examine the nonlinear relationships between sleep parameters and sarcopenia risks.

RESULTS

The covariate-adjusted analysis showed that a reverse J-shaped relationship for sleep duration and sarcopenia risk (P < .001) and a significant association for wake time and the SARC-F score (P = .009) in total sample, with considering age-related interaction. No associations were found in the other sleep parameters (bedtime and midsleep time) and sarcopenia in older adults. Similar associations were observed between wake time and the SARC-F score across age groups, while diverse associations of sleep duration with the SARC-F score were found in different age groups.

CONCLUSIONS

The sleep pattern is significantly associated with sarcopenia risks in aging adults. Improving inappropriate sleep behaviors in older adults is suggested to prevent a decline in muscle function and promote healthy aging.

CITATION

Huang W-C, Lin C-Y, Togo F, et al. Nonlinear associations between sleep patterns and sarcopenia risks in older adults. J Clin Sleep Med. 2022;18(3):731-738.

Objective underpinnings of self-reported sleep quality in middle-aged and older adults: the importance of N2 and wakefulness

STUDY OBJECTIVES

The measurable aspects of brain function (polysomnography, PSG) that are correlated with sleep satisfaction are poorly understood. Using recent developments in automated sleep scoring, which remove the within- and between-rater error associated with human scoring, we examine whether PSG measures are associated with sleep satisfaction.

DESIGN AND SETTING

A single night of PSG data was compared to contemporaneously collected measures of sleep satisfaction with Random Forest regressions. Whole and partial night PSG data were scored using a novel machine learning algorithm.

PARTICIPANTS

Community-dwelling adults (N = 3165) who participated in the Sleep Heart Health Study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Models explained 30% of sleep depth and 27% of sleep restfulness, with a similar top four predictors: minutes of N2 sleep, sleep efficiency, age, and minutes of wake after sleep onset (WASO). With increasing self-reported sleep quality, there was a progressive increase in N2 and decrease in WASO of similar magnitude, without systematic changes in N1, N3 or REM sleep. In comparing those with the best and worst self-reported sleep satisfaction, there was a range of approximately 30 min more N2, 30 min less WASO, an improvement of sleep efficiency of 7-8%, and an age span of 3-5 years. Examination of sleep most proximal to morning awakening revealed no greater explanatory power than the whole-night data set.

CONCLUSIONS

Higher N2 and concomitant lower wake is associated with improved sleep satisfaction. Interventions that specifically target these may be suitable for improving the self-reported sleep experience.

Does Long-Term Shift Work Increase the Risk of Dementia? A Systematic Review and Meta-Analysis

Background: Shift work is associated with impaired sleep quality and disrupted circadian rhythms, but the way in which it increases the risk of dementia remains controversial. We conducted a systematic review and meta-analysis to assess the integrated risk of dementia with shift work. Methods: Searching in PubMed, Cochrane Library, and the Web of Science databases, the relative risks of dementia with shift work were extracted from 12 included studies with 3975 dementia cases from 84 492 participants. The subgroup analysis was stratified by age, gender, sample size, dementia cases, shift schedule, occupation, and follow-up time. Heterogeneity analysis and publication bias analysis were conducted for quality control. Results: The pooled risk ratios (RRs) of dementia with shift work were 1.15 (95%CI = 1.02-1.30). The subgroup analysis found that continuous evening shifts reversibly reduced the risk, but continuous night shifts remarkedly increased the risk of dementia. In addition, a larger cohort and longer follow-up significantly increased the risk of dementia with shift work. Conclusion: Shift work shows mild increases in the risk of dementia using meta-analysis.

Age and Sex Differences in the Association of Sleep Duration and Overweight/Obesity among Chinese Participants Age above 45 Years: A Cohort Study

OBJECTIVES

We aimed to evaluate the association between sleep duration and obesity and estimate the attributable risk of sleep in the China Health and Retirement Longitudinal Study surveys (CHARLS).

METHODS

A total of 9061 adults aged 45 years above from CHARLS (2011-2015) were included. The main outcome of this study was incident overweight/obesity specific to general and abdominal obesity. Overweight/obesity was defined as BMI ≥ 23.0 (kg/m2) and BMI≥27.5 (kg/m2), respectively. Abdominal obesity was defined as waist circumference ≥90 cm for men and ≥80 cm for women. Self-reported sleep durations were obtained using a structured questionnaire. We assessed hazard ratios (HRs) and 95% confidence intervals (CIs) as well as the population attributable fraction (PAF) for associations between sleep duration and obesity.

RESULTS

986 and 606 participants were identified as overweight and general obesity respectively, 1253 experienced abdominal obesity events. In multivariable-adjusted models, participants with daytime sleep of 0-30 minutes and more than 30 minutes associated with 30% (HR: 0.70, 95% CI: 0.56-0.87) and 35% (HR: 0.65, 95% CI: 0.55-0.78) decreased incident overweight risk respectively compared to those having no daytime sleep, this association also found among females and middle-aged, not males or elderly. Similarly, 0-30 minutes (HR: 0.68, 95% CI: 0.48-0.96) and more than 30 minutes of daytime sleep (HR: 0.73, 95% CI: 0.59-0.91) were associated with a reduced risk of abdominal obesity, similar results also found among females and middle-aged. Compared with 7-9 hours of nocturnal sleep, people who slept 5-7 hours had a reduced risk of overweight (HR: 0.59, 95% CI=0.47-0.74),but not found in subgroups. The hazard role of long nocturnal sleep for abdominal obesity was only found among elderly (HR: 2.33, 95% CI=1.35-4.04) and males (HR: 2.24, 95% CI=1.17-4.29). Compared with moderate total sleepers (7-9hours/day), participants with short total sleep duration exhibited an elevated risk of overweight (HR: 1.13, 95% CI=1.00-1.28), this also found among middle-aged. The PAF for inadequate total sleep duration (<7 hours/day) was 10.77% for overweight individuals.

CONCLUSIONS

Insufficient sleep duration was associated with an elevated risk of overweight only detected among middle-aged not elderly and other subgroups specific by age. The risks for abdominal obesity were increased for males and middle-aged with long nocturnal sleep. Daytime sleep may significantly reduce the risk of overweight and abdominal obesity in female and middle-aged individuals. The link between sleep duration and obesity requires further study.

The association between obstructive sleep apnea and sleep spindles in middle-aged and older men: A community-based cohort study

STUDY OBJECTIVES

Sleep spindles show morphological changes in obstructive sleep apnea (OSA). However, previous small studies have limited generalisability, leaving associations between OSA severity measures and spindle metrics uncertain. This study examined cross-sectional associations between OSA severity measures and spindle metrics among a large population-based sample of men.

METHODS

Community-dwelling men with no previous OSA diagnosis underwent home-based polysomnography. All-night EEG (F4-M1) recordings were processed for artefacts and spindle events identified using previously validated algorithms. Spindle metrics of interest included frequency (Hz), amplitude (µV 2), overall density (11-16 Hz), slow density (11-13 Hz), and fast density (13-16 Hz) (number/minute). Multivariable linear regression models controlling for demographic, biomedical, and behavioural confounders were used to examine cross-sectional associations between OSA severity measures and spindle metrics.

RESULTS

In adjusted analyses, higher apnea-hypopnea index (AHI/h, as a continuous variable) and percentage total sleep time with oxygen saturation <90% (TST90) were associated with decreased slow spindle density (AHI, B= -0.003, p=0.032; TST90, B= -0.004, p=0.047) but increased frequency (AHI, B=0.002, p=0.009; TST90, B=0.002, p=0.043). Higher TST90 was also associated with greater spindle amplitude (N2 sleep, B=0.04, p=0.011; N3 sleep, B=0.11, p<0.001). Furthermore, higher arousal index was associated with greater spindle amplitude during N2 sleep (B=0.31, p<0.001) but decreased overall density (B= -1.27, p=0.030) and fast density (B= -4.36, p=0.028) during N3 sleep.

CONCLUSIONS

Among this large population-based sample of men, OSA severity measures were independently associated with spindle abnormalities. Further population studies are needed to determine associations between spindle metrics and functional outcomes.

The relationship between sleep quality and quality of life in aging: a systematic review and meta-analysis

This study examined the available literature concerning the association between sleep quality and quality of life (QoL) in autonomous older people with no sleep disorders. A systematic review and meta-analysis were conducted on studies identified in the PsycInfo, PubMed and Scopus databases that examined the associations between QoL and sleep quality in older adults. Our systematic literature search identified 23 studies concerning a total of 21,092 participants (range of mean ages: 58-79 years). The results showed that self-reported sleep quality, but not objective sleep quality, correlated positively with QoL with a moderate effect size (for self-reported sleep quality, the overall estimate of the average effect size was a Pearson's r = .28 [95% CI: .34, .23]; for objective sleep quality, it was r = .01 [.12, -.09]). This also applied to the main domains of QoL concerning physical and psychological health, social relationships and environmental aspects (the estimated average effect sizes ranged from Pearson's r = .13 to r = .35). These findings highlight the influence of sleep quality, and particularly of self-reported sleep quality, on QoL (as a whole and in its specific domains) in older adults with normal aging and no insomnia. This influence should therefore be investigated systematically when examining QoL.

Maternal Sleep and Related Pregnancy Outcomes: A Multicenter Cross-Sectional Study in 11 Provinces of Iran

Objective: Sleep disturbance during pregnancy is one of the most common maternal complaints. Not only does it play a crucial role in a mother’s life, but also it comes with a multitude number of complications. This study aimed at assessing the association between sleep disturbance in pregnancy and maternal and child outcomes.

Materials and methods: This was a multicenter cross-sectional study, conducted on pregnant women across 11 provinces in Iran in 2018. Sleep disturbance as a composite variable was defined using the principal component analysis based on five questions. Abortion, anemia in the first and third trimester, gestational diabetes, gestational age, glucose tolerance test (GTT), fasting blood sugar (FBS), mode of delivery, low birth weight and stillbirth were defined as study outcomes.

Results: Totally, 3675 pregnant women enrolled in the study. Most of the participants (84.5%) reported that their sleep duration is less than 8 hours per day. The prevalence of sleep disturbance was 20.7% (95% CI: 19.1, 22.3). After adjusting for maternal age, education, job, place of residency and physical violence, sleep disturbance would increase the odds of abortion (p=0.009), anemia in both first (p=0.001) and third (p=0.003) trimester, gestational age (p=0.049), abnormal FBS (p=0.015) and cesarean section (p<0.001).

Conclusion: Regarding the effect of sleep quality on maternal outcomes, planning and implementing a suitable intervention in the context of primary health care is necessary. Increasing the awareness of mothers, health workers and medical personnel about the suitable quality and quantity of sleep during pregnancy is of great importance.

Perceived versus objective sleep quality in long-stay hospitalised older adults-a mixed methods study

BACKGROUND

Hospital inpatients experience substantial sleep problems that have been linked with worse health outcomes, poor quality of life and the post-hospital syndrome. However, little is known about assessing sleep issues in older hospitalised patients.

OBJECTIVE

To conduct an in-depth investigation on hospitalised older adults' sleep challenges and methods of sleep assessment.

DESIGN

Cross-sectional observational study.

SETTING

Public hospital inpatient unit.

SUBJECTS

Long-stay hospitalised older adults.

METHODS

Data were collected using validated sleep questionnaires, actigraphy devices and qualitative interviews. Quantitative data were analysed with descriptive statistics, multiple logistic regression and Cohen's Kappa. Qualitative data were analysed with qualitative content analysis; findings compared to the quantitative assessments.

RESULTS

We collected data on 33 older long-stay hospital inpatients, who were mean (SD) 80.2(7.4) years old, 57.6% female and were hospitalised following stroke, medical illness and orthopaedic fracture. Mean (SD) total sleep time and actigraphic sleep efficiency were 480.6(73.6) minutes and 81.5(11.2)%, respectively. About, 57.6% were poor sleepers (Pittsburgh Sleep Quality Index [PSQI]) and 30.8% had indicators of clinical depression/low quality of life (WHO-5 well-being index). Three main themes were identified: "sleep assessment"; "factors that affect sleep"; "expectations of sleep". Bad sleepers were more likely to feel a lack of control over their sleep, while good sleepers spoke about the ability to adjust and accept their circumstances.

CONCLUSIONS

We found high levels of sleep problems and identified substantial discrepancies between the validated sleep questionnaire and qualitative response data. Our findings indicate that standard assessment tools, such as PSQI, may not be suitable to assess sleep in hospitalised older adults and call for further investigations to build more appropriate methods. Further exploring psychological factors and expectations could potentially lead to novel interventions to improve sleep in this setting.

Chronobiology and the case for sleep health interventions in the community

Our sleep-wake cycle is determined by the interaction between our homeostatic sleep drive and circadian rhythm. Each of us has a personalised biological rhythm or chronotype that determines the optimal time to fall asleep and wake up. Chronic sleep deprivation has been linked to the development of several physical and mental health disorders, as well as accidents and occupational errors. Around the world, growing recognition of the importance of sleep has led to the adoption of practices that promote sleep health. Given that Singaporeans were consistently found to be one of the most sleep-deprived populations in the world, we believe that there is an urgent need to pursue the introduction of community-based sleep health interventions here. This includes sleep education and promotion of sleep hygiene, adopting practices to reduce social jetlag and improve sleep health, and enhancing screening and treatment of sleep disorders.

Gender differences in nighttime sleep patterns and variability across the adult lifespan: a global-scale wearables study

STUDY OBJECTIVES

Previous research on sleep patterns across the lifespan have largely been limited to self-report measures and constrained to certain geographic regions. Using a global sleep dataset of in situ observations from wearable activity trackers, we examine how sleep duration, timing, misalignment, and variability develop with age and vary by gender and BMI for nonshift workers.

METHODS

We analyze 11.14 million nights from 69,650 adult nonshift workers aged 19-67 from 47 countries. We use mixed effects models to examine age-related trends in naturalistic sleep patterns and assess gender and BMI differences in these trends while controlling for user and country-level variation.

RESULTS

Our results confirm that sleep duration decreases, the prevalence of nighttime awakenings increases, while sleep onset and offset advance to become earlier with age. Although men tend to sleep less than women across the lifespan, nighttime awakenings are more prevalent for women, with the greatest disparity found from early to middle adulthood, a life stage associated with child-rearing. Sleep onset and duration variability are nearly fixed across the lifespan with higher values on weekends than weekdays. Sleep offset variability declines relatively rapidly through early adulthood until age 35-39, then plateaus on weekdays, but continues to decrease on weekends. The weekend-weekday contrast in sleep patterns changes as people age with small to negligible differences between genders.

CONCLUSIONS

A massive dataset generated by pervasive consumer wearable devices confirms age-related changes in sleep and affirms that there are both persistent and life-stage dependent differences in sleep patterns between genders.

Sleep characteristics, cognitive performance, and gray matter volume: findings from the BiDirect Study

STUDY OBJECTIVES

Sleep is essential for restorative metabolic changes and its physiological correlates can be examined using overnight polysomnography. However, the association between physiological sleep characteristics and brain structure is not well understood. We aimed to investigate gray matter volume and cognitive performance related to physiological sleep characteristics.

METHODS

Polysomnographic recordings from 190 community-dwelling participants were analyzed with a principal component analysis in order to identify and aggregate shared variance into principal components. The relationship between aggregated sleep components and gray matter volume was then analyzed using voxel-based morphometry. In addition, we explored how cognitive flexibility, selective attention, and semantic fluency were related to aggregated sleep components and gray matter volume.

RESULTS

Three principal components were identified from the polysomnographic recordings. The first component, primarily described by apnea events and cortical arousal, was significantly associated with lower gray matter volume in the left frontal pole. This apnea-related component was furthermore associated with lower cognitive flexibility and lower selective attention.

CONCLUSIONS

Sleep disrupted by cortical arousal and breathing disturbances is paralleled by lower gray matter volume in the frontal pole, a proposed hub for the integration of cognitive processes. The observed effects provide new insights on the interplay between disrupted sleep, particularly breathing disturbances and arousal, and the brain.

Spousal Educational Attainment and Sleep Duration Among American Older Adults

OBJECTIVES

Sleep has consistently been shown to have a dyadic nature among married older adults; however, less is known about the influence of a spouses' social characteristics on one's own sleep. Focusing on older adults, we examined the association between one's spouses' educational attainment and one's own sleep duration.

METHOD

We used the 2004-2018 National Health Interview Survey (NHIS) to analyze heterosexual married adults aged 50-84 (N = 89,180). Respondents reported typical sleep duration in a 24-hr period, which was categorized as short (≤6 hr), normal (7-8 hr), or long (≥9 hr). We fit multinomial logistic regression models predicting these categories of sleep duration and accounted for demographic, household socioeconomic characteristics, and health/health behaviors. Using interaction terms, we tested if the association varied by the respondent's gender and educational attainment.

RESULTS

Older adults married to spouses with college or more education had significantly lower relative risk of short sleep than those whose spouses had some college, high school, or less than high school education, net of the covariates including their own education. The benefit of higher levels of spousal education was significantly more protective against short sleep for women and more highly educated older adults.

DISCUSSION

Older adults married to spouses with high levels of education reported more favorable sleep durations, but this benefit was significantly stronger for women and the highly educated which has important implications for their aging. These findings suggest that social inequality may condition the dyadic nature of sleep for heterosexual married older adults.

Modeling sleep onset misperception in insomnia

OBJECTIVES

To extend and validate a previously suggested model of the influence of uninterrupted sleep bouts on sleep onset misperception in a large independent data set.

METHODS

Polysomnograms and sleep diaries of 139 insomnia patients and 92 controls were included. We modeled subjective sleep onset as the start of the first uninterrupted sleep fragment longer than Ls minutes, where parameter Ls reflects the minimum length of a sleep fragment required to be perceived as sleep. We compared the so-defined sleep onset latency (SOL) for various values of Ls. Model parameters were compared between groups, and across insomnia subgroups with respect to sleep onset misperception, medication use, age, and sex. Next, we extended the model to incorporate the length of wake fragments. Model performance was assessed by calculating root mean square errors (RMSEs) of the difference between estimated and perceived SOL.

RESULTS

Participants with insomnia needed a median of 34 minutes of undisturbed sleep to perceive sleep onset, while healthy controls needed 22 minutes (Mann-Whitney U = 4426, p < 0.001). Similar statistically significant differences were found between sleep onset misperceivers and non-misperceivers (median 40 vs. 20 minutes, Mann-Whitney U = 984.5, p < 0.001). Model outcomes were similar across other subgroups. Extended models including wake bout lengths resulted in only marginal improvements of model outcome.

CONCLUSIONS

Patients with insomnia, particularly sleep misperceivers, need larger continuous sleep bouts to perceive sleep onset. The modeling approach yields a parameter for which we coin the term Sleep Fragment Perception Index, providing a useful measure to further characterize sleep state misperception.

Symptom clusters and quality of life in persons with multiple sclerosis across the lifespan

PURPOSE

To describe symptom clusters based on severity of co-occurring symptoms among adults with multiple sclerosis (MS) by age groups and to further examine symptom clusters as a correlate of quality of life (QOL) by age groups.

METHODS

This cross-sectional study enrolled persons with MS between 20 and 79 years of age who completed measures of fatigue, depression, anxiety, sleep quality, and QOL using the 36-Item Short Form Health Survey. Bivariate correlation and partial correlation analyses examined associations among symptoms, QOL, and MS characteristics. K-means cluster analyses determined symptom clusters among the full sample and pre-determined age groups (i.e., 20-39, 40-59, and 60-79). One-way ANOVAs examined differences in QOL among clusters for the overall sample and by age groups.

RESULTS

Among the overall sample of 205 participants, symptoms were significantly correlated with QOL and three distinct clusters were identified and differentiated by the magnitude of symptom experience (i.e., mild, moderate, and severe). Results were consistent among young and middle-aged adults; however, among older adults two severe sleep problem clusters were identified that were distinguished by moderate versus severe fatigue, depression, and anxiety. ANOVAs among the overall sample indicated that the three symptom clusters varied significantly for both physical component scores, F(2, 202) = 12.03, p < .001, η2 = .10, and mental component scores, F(2, 202) = 137.92, p < .001, η2 = .58; severe symptom cluster was associated with worse QOL. Patterns in the age subgroup ANOVAs were consistent.

CONCLUSIONS

Given the strong association between severity of symptom clusters and QOL, approaches for targeting co-occurring symptoms are critically needed.

Experimental diffuse brain injury and a model of Alzheimer's disease exhibit disease-specific changes in sleep and incongruous peripheral inflammation

Elderly populations (≥65 years old) have the highest risk of developing Alzheimer's disease (AD) and/or obtaining a traumatic brain injury (TBI). Using translational mouse models, we investigated sleep disturbances and inflammation associated with normal aging, TBI and aging, and AD. We hypothesized that aging results in marked changes in sleep compared with adult mice, and that TBI and aging would result in sleep and inflammation levels similar to AD mice. We used female 16-month-old wild-type (WT Aged) and 3xTg-AD mice, as well as a 2-month-old reference group (WT Adult), to evaluate sleep changes. WT Aged mice received diffuse TBI by midline fluid percussion, and blood was collected from both WT Aged (pre- and post-TBI) and 3xTg-AD mice to evaluate inflammation. Cognitive behavior was tested, and tissue was collected for histology. Bayesian generalized additive and mixed-effects models were used for analyses. Both normal aging and AD led to increases in sleep compared with adult mice. WT Aged mice with TBI slept substantially more, with fragmented shorter bouts, than they did pre-TBI and compared with AD mice. However, differences between WT Aged and 3xTg-AD mice in immune cell populations and plasma cytokine levels were incongruous, cognitive deficits were similar, and cumulative sleep was not predictive of inflammation or behavior for either group. Our results suggest that in similarly aged individuals, TBI immediately induces more profound sleep alterations than in AD, although both diseases likely include cognitive impairments. Unique pathological sleep pathways may exist in elderly individuals who incur TBI compared with similarly aged individuals who have AD, which may warrant disease-specific treatments in clinical settings.

Biological Rhythm and Chronotype: New Perspectives in Health

The circadian rhythm plays a fundamental role in regulating biological functions, including sleep–wake preference, body temperature, hormonal secretion, food intake, and cognitive and physical performance. Alterations in circadian rhythm can lead to chronic disease and impaired sleep. The circadian rhythmicity in human beings is represented by a complex phenotype. Indeed, over a 24-h period, a person’s preferred time to be more active or to sleep can be expressed in the concept of morningness–eveningness. Three chronotypes are distinguished: Morning, Neither, and Evening-types. Interindividual differences in chronotypes need to be considered to reduce the negative effects of circadian disruptions on health. In the present review, we examine the bi-directional influences of the rest–activity circadian rhythm and sleep–wake cycle in chronic pathologies and disorders. We analyze the concept and the main characteristics of the three chronotypes.

Life Satisfaction, Positive Affect, and Sleep Impairment in Masters Athletes: Modulation by Age, Sex, and Exercise Type

Introduction

The masters athlete has been proposed as a model of successful aging. Research studies investigating psychological outlook in older athletes have primarily addressed negative affects including depression, anxiety, and stress. The impact of lifelong exercise on positive affect and life satisfaction as well as sleep impairment that could impact on these psychological states is largely unknown.

Methods

A series of questionnaires (general life satisfaction, positive affect, and sleep-related impairment) were administered to 240 masters athletes participating in the World Masters Athletics Championships. Total raw scores were converted into T scores for comparison with the general population. Meaningful difference was defined by the PROMIS^® as one-half standard deviation from the centering sample.

Results

Meaningful differences were observed for improved general life satisfaction and reduced sleep impairment for all masters athletes. Positive affect did not reach the meaningful difference threshold. No significant sex differences were found for any of the questionnaires (all p > 0.05). Similarly, no significant differences were found between endurance, sprint, and strength/power sports for general life satisfaction (p = 0.18), positive affect (p = 0.46), and sleep impairment (p = 0.77). In general, life satisfaction increased with age (r = 0.15, p = 0.02), and sleep impairment trended towards reduction with age (r = −0.13, p = 0.05). Positive affect demonstrated no correlation with age (r = 0.09, p = 0.18).

Conclusion

This study demonstrates that the lifestyles of masters athletes contribute to improved general life satisfaction and reduced sleep impairment but not improved positive affect. The beneficial effects were observed irrespective of age, gender, and sporting types.

Loneliness and social isolation is associated with sleep problems among older community dwelling women and men with complex needs

Sleep problems, loneliness and social isolation often increase with age, significantly impacting older adults’ health and wellbeing. Yet general population health empirical evidence is surprisingly scant. Using the largest national database to date, cross-sectional and longitudinal analyses was undertaken on 140,423 assessments from 95,045 (women: 61.0%) community living older adults aged ≥ 65 years having standardised home care assessments between 1 July 2012 and 31 May 2018 to establish the prevalence and relationships between insufficient sleep, excessive sleep, loneliness and social isolation. At first assessment, insufficient sleep (women: 12.4%, men: 12.7%) was more commonly reported than excessive sleep (women: 4.7%, men: 7.6%). Overall, 23.6% of women and 18.9% of men reported feeling lonely, while 53.8% women and 33.8% men were living alone. In adjusted longitudinal analyses, those who were lonely and socially isolated were more likely to experience insufficient sleep. Respondents with excessive sleep were more likely to live with others. Both loneliness and social isolation contributed to insufficient sleep, synergistically. Loneliness, social isolation and health-concerns may affect the restorative properties of sleep over and above the effects of ageing. Further research is warranted.

Behavioral and exercise interventions for sleep dysfunction in the elderly: a brief review and future directions

Purpose

The impact of sleep-related changes and disorders in the geriatric populations are of utmost concern due to health consequences and increased risk of injury as well as injuring others as a result of poor sleep. The purpose of this paper is to provide a brief review of the current state of the literature with regard to sleep, aging, common non-pharmacological interventions, and the potential use of exercise in combination with behavioral interventions.

Methods

Initially, this manuscript focuses on a brief (nonsystematic) review of sleep parameters and physiology that are associated with the aging process. Subsequently, information regarding sleep disorders in the elderly in general, and insomnia in particular are discussed. Last, a brief review of current recommended interventions is provided.

Results

The current major nonpharmacological interventions are described including Cognitive Behavioral Therapy for Insomnia (CBT-I). The potential use of exercise as a safe intervention for poor sleep is discussed. Finally, a call is made for increased research that examines the combination of traditional behavioral interventions with exercise.

Hypothalamic aging and hormones

It is the heterogeneous changes of hypothalamic functions that determine the chronological sequence of aging in mammals. Recently, it was hypothesized by Cai the decrease in slow-wave sleep (SWS) resulting from skin aging as responsible for the degeneration of hypothalamic suprachiasmatic nucleus (SCN). It was soon hypothesized by the European people in television that the increase in body fat as responsible for the degeneration of male preoptic sexually dimorphic nucleus (SDN-POA), via the aromatase converting testosterone to estradiol as proposed by Cohen. It is the hypothalamic paraventricular nucleus (PVN) that remains unchanged in neuron number during aging for psychological stress. In this chapter, it is briefly reviewed more manifestations of hypothalamic related mammalian aging processes, including (1) the aging of ovary by lipid, estradiol and hypothalamus; (2) the aging of muscle, stomach, intestine, thymus, and the later aging of brain, regulated by growth hormone/insulin-like growth factor 1(GH/IGF1); (3) the cardiovascular hypertension from PVN activation, the bone and other peripheral aging by psychological stress, and that of kidney by vasopressin. It is classified these aging processes by the primary regulation from one of the three hypothalamic nuclei, although still necessary to investigate and supplement their secondary regulation by the hypothalamic nuclei in future. It is the hypothalamic structural changes that shift the functional balance among these three hypothalamic systems toward aging.

A functional linear modeling approach to sleep-wake cycles in dogs

The study of companion (pet) dogs is an area of great translational potential, as they share a risk for many conditions that afflict humans. Among these are conditions that affect sleep, including chronic pain and cognitive dysfunction. Significant advancements have occurred in the ability to study sleep in dogs, including development of non-invasive polysomnography; however, basic understanding of dog sleep patterns remains poorly characterized. The purpose of this study was to establish baseline sleep-wake cycle and activity patterns using actigraphy and functional linear modeling (FLM), for healthy, adult companion dogs. Forty-two dogs were enrolled and wore activity monitors for 14 days. FLM demonstrated a bimodal pattern of activity with significant effects of sex, body mass, and age; the effect of age was particularly evident during the times of peak activity. This study demonstrated that FLM can be used to describe normal sleep-wake cycles of healthy adult dogs and the effects of physiologic traits on these patterns of activity. This foundation makes it possible to characterize deviations from normal patterns, including those associated with chronic pain and cognitive dysfunction syndrome. This can improve detection of these conditions in dogs, benefitting them and their potential as models for human disease.

The core circadian component, Bmal1, is maintained in the pineal gland of old killifish brain

Circadian rhythm is altered during aging, although the underlying molecular mechanisms remain largely unknown. Here, we used the turquoise killifish as a short-lived vertebrate model to examine the effects of aging on the major circadian network comprising the four mammalian clock protein homologs, Bmal1, Clockb, Cry1b, and Per3, which are highly conserved in the killifish with 50%–85% amino acid sequence identity to their human counterparts. The amplitude of circadian rhythm was smaller in old fish (14 weeks) than in young fish (6 weeks). In old fish brain, the Bmal1 protein level was significantly downregulated. However, the Bmal1 interaction with Clockb and chromatin binding of Bmal1 to its downstream target promoters were retained. Furthermore, Bmal1 was relatively well maintained in the pineal gland compared with other regions of the old fish brain. The results suggest that the circadian clock system in the killifish becomes spatially confined to the pineal gland upon aging.

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The amplitude of free-running circadian rhythms decreases during aging in killifish

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Core clock genes are highly conserved in the turquoise killifish genome

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Bmal1 protein expression decreases in whole brain tissue with aging

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Bmal1 expression is relatively well maintained in the pineal gland with aging