Sleep Profile Research Articles

Different patterns of treatment response to Cognitive-Behavioural Therapy for Insomnia (CBT-I) in psychosis

People with psychosis benefit enormously from Cognitive Behavioural Therapy for Insomnia (CBTI), although some variability exists in treatment outcomes. While recent efforts have focused on profiling sleep at treatment initiation, an alternative methodological approach involves using treatment response as a starting point to better understand what constitutes an effective treatment. This study used Grade of Membership analysis (GoM) to estimate the occurrence of unique treatment outcomes and associated patient characteristics. Outcome measures included changes in sleep (self-reported latency, efficiency, duration, quality), functional outcomes (daytime dysfunction, negative mood, need for sleep medication) and treatment goal, collected in 50 individuals with a psychotic disorder and insomnia who underwent CBT-I treatment. Three distinct profiles were identified: (1) Strong responders, who met their treatment goals and showed broad improvements in both sleep and functional domains; (2) Partial responders, who showed sleep improvements (particularly in total sleep time), without noticeable gains in function, and who were predominantly female; and (3) Non-responders who showed little treatment response and failed to meet their treatment goals. This group was also more likely to have greater psychopathology (high levels of negative mood and psychotic symptoms, and antipsychotic medication dosage). These findings suggest that (i) CBT-I can serve to improve sleep and daytime function (although sleep can improve independently from function), (ii) client-elicited treatment goals are a key predictor of CBT-I response, (iii) other important variables associated with treatment response include sleep profile, clinical acuity, and sex.

The association between alcohol consumption and sleep disorders among older people in the general population

The relationship between alcohol consumption and sleep disturbance is complex. The association of alcohol dependence with insomnia is likely to be bidirectional in nature. Alcohol use is common among older people in many societies and the prevalence of insomnia tends to increase with age, therefore this group warrants particular consideration. We explored the cross sectional and long term (30 years) associations between alcohol drinking (volume and hazardous drinking) and sleep duration and insomnia in a general population study of older adults (6,117 male and female civil servants followed for 30 years). For men, drinking more than 21 units (approximately 168 grams) of alcohol per week, compared with not drinking, was associated with waking several times a night (odds ratio 1.30, confidence intervals 1.02–1.66). Men who maintained a heavy volume of drinking over the three decades of observation, or who had an unstable consumption pattern, tended to have worse sleep profiles in terms of waking tired and waking several times. Sustained male hazardous drinking (as measured by the AUDIT-C scale) was also associated with worse sleep profiles. Findings for women were not so clear. In this population based setting, drinking high volumes of alcohol may contribute to the prevalence of sleep problems in older age, particularly for men. People in this age group should be discouraged from using alcohol as a sleep aid.

Workload Intensity and Rest Periods in Professional Ballet: Connotations for Injury.

Fatigue and overwork have been cited as the main cause of injury with the dance profession. Previous research has shown a difference in workload between professional dancers of different rank, but the role of sex has not been examined. The purpose of this study was to determine workload intensity, rest, and sleep profiles of professional ballet dancers. 48 professional ballet dancers (M=25, F=23) took part in an observational design over 7-14 days using triaxial accelerometer devices. Minutes in METS at different intensities, total time asleep and rest breaks were analysed. Significant main effects for rank (p<0.001) and rank by sex (p=0.003) for total PA, working day activity, post work activity and sleep. Sleep ranged between 2.4-9.6 h per night. All participants spent more time between 1.5-3 METS outside of work. Significant amounts of exercise where carried out outside of their work day, therefore when injury is reported per 1000 h dance activity, this extra-curricular activity might need to be included. When looking at potential causes of injury in dance, a global perspective of physical activity is required that includes activity outside of work and sleep patterns, all activities that influence physiological recovery.

Depressive Symptoms, Sleep Profiles and Serum Melatonin Levels in a Sample of Breast Cancer Patients.

BackgroundChronobiological changes have been detected in various physiological functions of patients with breast cancer, suggesting dysregulation in the pineal gland and melatonin secretion. This study aimed to assess and measure serum melatonin levels pre- and postoperatively in patients who had been diagnosed for the first time with breast cancer.MethodsA sample of first-time breast cancer patients, consisting of 45 women aged 25–65 years, was evaluated and psychometric assessment was completed using the Beck Depression Inventory (BDI), Insomnia Severity Index (White, Weinberg et al) and the Epworth Sleepiness Scale (Cardoso, Spence et al). The Morningness-Eveningness questionnaire (MEQ) was used to assess the chronotype. Serum melatonin levels were measured by radioimmunoassay.ResultsMorning and moderately morning chronotypes were prevalent among the sample (25%, 45.8%, respectively). The finding of a mean BDI score of 13.5±11.2 indicated that depressive symptoms were prevalent among the sample. Despite the finding that a mean of the participants apparently had no symptoms of daytime sleepiness (the mean and standard deviations of the ESS were 7.5±4.4), scores on the ISI (a mean of 16.7±SD 7.3) indicated that insomnia symptoms were prevalent in the sample. Melatonin levels showed an inverse relationship with insomnia severity as measured by the ISI and depression severity, as assessed by the BDI. The postoperative melatonin levels were higher than the preoperative levels. Additionally, the psychometric profile differed among various pathological types of breast cancer according to their hormone receptor profile.ConclusionSerum melatonin levels correlated significantly with self-reported sleep quality and psychometric profiles of depression in the present sample of breast cancer patients. The melatonin assay, which is relatively easy to carry out, provided a convenient, objective measure of an important biological correlate of sleep quality and depression. This assay thus represented a confirmatory alternative to the self-report instruments, which may sometimes be unreliable. Future studies should further evaluate the utility of melatonin measures in psychiatric and sleep complaints of breast cancer patients.

Effectiveness of an mHealth Intervention for Infant Sleep Disturbances

Bedtime problems and night wakings are highly prevalent in infants. This study assessed the real-world effectiveness of an mHealth behavioral sleep intervention (Customized Sleep Profile; CSP). Caregivers (83.9% mothers) of 404 infants (age 6 to 11.9 m, M = 8.32 m, 51.2% male) used the CSP (free and publicly available behavioral sleep intervention delivered via smartphone application, Johnson’s® Bedtime® Baby Sleep App). Caregivers completed the Brief Infant Sleep Questionnaire–Revised (BISQ-R) at baseline and again 4 to 28 days later. Changes in sleep patterns were analyzed, based on sleep problem status (problem versus no problem sleepers; PS; NPS). Sleep onset latency improved in both groups. Earlier bedtimes, longer continuous stretches of sleep, as well as decreased number and duration of night wakings, were evident in the PS group only. The BISQ-R Total score, total nighttime sleep, and total 24-hour sleep time improved for both groups, with a greater change for the PS group. Further, caregivers of infants in the PS group decreased feeding (bedtime and overnight) and picking up overnight, and perceived better sleep. Bedtime routine regularity, bedtime difficulty, sleep onset difficulty, and caregiver confidence improved for both groups, with the PS group showing a greater magnitude of change. Thus, a real-world, publicly available, mHealth behavioral sleep intervention was associated with improved outcomes for older infants. Intervention recommendations resulted in changes in caregivers’ behavior and improvements in caregiver-reported sleep outcomes in infants, in as few as 4 days.

Depressive symptoms and chronotypes of elderly nursing home residentes: A case management study.

ABSTRACT.Institutionalization potentiates the tendency for specific sleep disturbances which occur with aging, besides negative health consequences such as increased rate of depressive symptoms.Objective:To compare sleep profile and depressive symptoms in elderly nursing home residents, highlighting gender differences.Methods:A quantitative descriptive study of 29 elderly from two different nursing homes was conducted. A sociodemographics questionnaire, Sleep Diary, Morningness-Eveningness Questionnaire and the 15-item Geriatric Depression Scale were applied. Data were analyzed using descriptive statistics, Student’s t-test and the Mann-Whitney U-test.Results:The sample comprised individuals that were predominantly female (72%), aged 80-90 years (48%), widowed (66%) and low-educated (83%). The women were found to sleep and awake later than the men. Regarding chronotypes, the women were classified as evening types and men as intermediate/indifferent types. Most of the elderly exhibited symptoms of major depression (48%). Compared to men, women had more depressive symptoms in both dysthymia and major depression categories.Conclusion:No significant differences were evident on comparisons of sleep profile and depressive symptoms, but elderly with the intermediate chronotype scored lower on the depressive symptoms scale.

A Retrospective Study Suggests that Chronic Insomnia Behaves as a Neurodegenerative Disorder

Insomnia is a prevalent sleep disorder. We examined chronic insomnia in terms of subjective and objective measures, according to self-reported duration of disorder. 443 patients were included from a sleep clinic diagnosed with chronic insomnia (ICSD3 criteria). Patients were retrospectively evaluated in terms of medical interview, sleep questionnaires, a standard polysomnography study, and subdivided in subgroups according to disorder duration. We compared patient’s results to a control group. Insomnia and control groups were significantly different in terms of TST, SE, SOL, N1 sleep, REM sleep, REM latency and number of REM episodes (p<0.05). For the group of ≤1 year of insomnia disorder all PSG parameters were statistically different from controls, except N2% and N3%, REM latency, and number of REM episodes. In the groups of 2 to 4 years, 10 to 19 years, and ≥ 20 years of insomnia we found the same differences except for REM sleep. On the contrary, in a subgroup analysis of 5 to 9 years of insomnia disorder duration, no differences to control group were found in TST, N1 or REM sleep to control group, adjusted for age. The polysomnographic sleep profile of chronic insomnia patients is different over time. It sketches an initial attempt of compensation in initial years of insomnia, which seems to disappear in long time chronic insomnia patients, as we usually see in others neurodegenerative disorders. Future studies are needed to clarify the natural history of chronic insomnia disorder and its behaviour as a neurodegenerative disorder.

Memory quality modulates the effect of aging on memory consolidation during sleep: Reduced maintenance but intact gain

Successful consolidation of associative memories relies on the coordinated interplay of slow oscillations and sleep spindles during non-rapid eye movement (NREM) sleep. This enables the transfer of labile information from the hippocampus to permanent memory stores in the neocortex. During senescence, the decline of the structural and functional integrity of the hippocampus and neocortical regions is paralleled by changes of the physiological events that stabilize and enhance associative memories during NREM sleep. However, the currently available evidence is inconclusive as to whether and under which circumstances memory consolidation is impacted during aging. To approach this question, 30 younger adults (19–28 years) and 36 older adults (63–74 years) completed a memory task based on scene–word associations. By tracing the encoding quality of participants’ individual memory associations, we demonstrate that previous learning determines the extent of age-related impairments in memory consolidation. Specifically, the detrimental effects of aging on memory maintenance were greatest for mnemonic contents of intermediate encoding quality, whereas memory gain of poorly encoded memories did not differ by age. Ambulatory polysomnography (PSG) and structural magnetic resonance imaging (MRI) data were acquired to extract potential predictors of memory consolidation from each participant’s NREM sleep physiology and brain structure. Partial Least Squares Correlation was used to identify profiles of interdependent alterations in sleep physiology and brain structure that are characteristic for increasing age. Across age groups, both the ‘aged’ sleep profile, defined by decreased slow-wave activity (0.5–4.5 ​Hz), and a reduced presence of slow oscillations (0.5–1 ​Hz), slow, and fast spindles (9–12.5 ​Hz; 12.5–16 ​Hz), as well as the ‘aged’ brain structure profile, characterized by gray matter reductions in the medial prefrontal cortex, thalamus, entorhinal cortex, and hippocampus, were associated with reduced memory maintenance. However, inter-individual differences in neither sleep nor structural brain integrity alone qualified as the driving force behind age differences in sleep-dependent consolidation in the present study. Our results underscore the need for novel and age-fair analytic tools to provide a mechanistic understanding of age differences in memory consolidation.

To bed or not to bed: the sleep question?

BackgroundSleep deprivation and fatigue from long-shift work impacts doctors' personal safety, inhibits cognitive performance and risks clinical error. The aim of this study was to assess the sleep quality of...

New physiological bench test reproducing nocturnal breathing pattern of patients with sleep disordered breathing.

Previous studies have shown that Automatic Positive Airway Pressure devices display different behaviors when connected to a bench using theoretical respiratory cycle scripts. However, these scripts are limited and do not simulate physiological behavior during the night. Our aim was to develop a physiological bench that is able to simulate patient breathing airflow by integrating polygraph data. We developed an algorithm analyzing polygraph data and transformed this information into digital inputs required by the bench hardware to reproduce a patient breathing profile on bench. The inputs are respectively the simulated respiratory muscular effort pressure input for an artificial lung and the sealed chamber pressure to regulate the Starling resistor. We did simulations on our bench for a total of 8 hours and 59 minutes for a breathing profile from the demonstration recording of a Nox T3 Sleep Monitor. The simulation performance results showed that in terms of relative peak-valley amplitude of each breathing cycle, simulated bench airflow was biased by only 1.48% ± 6.80% compared to estimated polygraph nasal airflow for a total of 6,479 breathing cycles. For total respiratory cycle time, the average bias ± one standard deviation was 0.000 ± 0.288 seconds. For patient apnea events, our bench simulation had a sensitivity of 84.7% and a positive predictive value equal to 90.3%, considering 149 apneas detected both in polygraph nasal simulated bench airflows. Our new physiological bench would allow personalizing APAP device selection to each patient by taking into account individual characteristics of a sleep breathing profile.

The difference in sleep, sedentary behaviour, and physical activity between older adults with \u2018healthy\u2019 and \u2018unhealthy\u2019 cardiometabolic profiles: a cross-sectional compositional data analysis approach

BackgroundStudies have seldom used Compositional Data Analysis (CoDA) to map the effects of sleep, sedentary behaviour, and physical activity on older adults’ cardio-metabolic profiles. This study therefore aimed to illustrate how sleep, sedentary behaviour, and physical activity profiles differ between older adult groups (60–89 years), with ‘low’ compared to those with ‘high’ concentrations of endocrine cardio-metabolic disease risk markers, using CoDA.MethodNinety-three participants (55% female) wore a thigh-mounted triaxial accelerometer for seven consecutive free-living days. Accelerometer estimates of daily average hours of engagement in sedentary behaviour (SB), standing, light-intensity physical activity (LIPA), sporadic moderate-vigorous physical activity (sMVPA, accumulated with bouts between 1 and 10 min), 10-min moderate-vigorous physical activity (10MVPA, accumulated with bouts ≥10 min), in addition to self-reported sleeping hours were reported. Fasted whole blood concentrations of total cholesterol, triglyceride, glucose, and glycated haemoglobin, and serum lipoprotein lipase (LPL), interleukin-6 (IL-6), and procollagen III N-terminal propeptide were determined.ResultsTriglyceride concentration appeared to be highly dependent on 10MVPA engagement as the ‘low’ and ‘high’ concentration groups engaged in 48% more and 32% less 10MVPA, respectively, relative to the geometric mean of the entire study sample. Time-use composition of the ‘low’ LPL group’s engagement in 10MVPA was 26% less, while the ‘high’ LPL group was 7.9% more, than the entire study sample. Time-use composition of the ‘high’ glucose and glycated haemoglobin groups appeared to be similar as both engaged in more Sleep and SB, and less 10MVPA compared to the study sample. Participants with a ‘low’ IL-6 concentration engaged in 4.8% more Sleep and 2.7% less 10MVPA than the entire study sample. Time-use composition of the Total Cholesterol groups was mixed with the ‘low’ concentration group engaging in more Standing and 10MVPA but less Sleep, SB, LIPA, and sMVPA than the entire study sample.ConclusionOlder adults should aim to increase 10MVPA engagement to improve lipid profile and decrease SB engagement to improve glucose profile.

Sleep profile during fasting in PPAR-alpha knockout mice

Peroxisome proliferator-activated receptor alpha (PPARα) is a transcription factor that belongs to the nuclear receptor family and plays an important role in regulating gene expression associated with lipid metabolism. PPARα promotes hepatic fatty acid oxidation and ketogenesis in response to fasting. Because energy metabolism is known to affect sleep regulation, manipulations that change PPARα are likely to affect sleep and other physiological phenotypes. In this study, we examined the role of PPARα in sleep/wake regulation using PPARα knockout (KO) mice. Sleep, body temperature (BT), locomotor activity, arterial pressure (AP) and heart rate (HR) were recorded in KO mice and wild-type (WT) controls under ad libitum-fed conditions and 24-hour food deprivation (FD). KO and WT mice were identical in basal sleep amount, BT, mean AP and HR, although KO mice showed enhanced sleepiness (enhanced EEG slow-wave activity). In response to FD, KO mice showed a large drop in wakefulness and locomotor activity at the end of the dark phase, whereas WT mice did not. Similarly, AP and HR, which were suppressed by FD, decreased more in KO than in WT mice. Compared to WT mice, KO mice showed a reduced concentration of plasma ketone bodies and decreased mRNA expression of the ketogenic enzyme gene Hmgcs2 in the liver and brain under FD conditions. These results suggest that PPARα and/or lipid metabolism is involved in the maintenance of wakefulness and locomotor activity during fasting in mice.

Traumatic brain injury and sleep disturbances in combat-exposed service members and veterans: Where to go next?

To synthesize the current evidence on sleep disturbances in military service members (SMs) and veterans with traumatic brain injury (TBI). An electronic literature search first identified abstracts published from 2008-2018 inclusively referencing sleep, TBI, and military personnel from Operation Enduring Freedom, Operation Iraqi Freedom, Operation New Dawn, and Persian Gulf veterans. Selection criteria eliminated studies on non-combat TBI, open or penetrating injuries, and articles where the relationship between sleep and TBI was not directly examined. Articles on all military branches and components, those currently serving and veterans-ranging from medical chart reviews to clinical trials, were included. Forty-one articles were selected for full text-review. Twenty-four papers estimated the prevalence of sleep disturbances in TBI. Eight studies demonstrated the contribution of common co-occurring conditions, most notably posttraumatic stress disorder, to the relationship between disrupted sleep and TBI. Ten studies differentiated sleep profiles between military SMs and veterans with and without acute TBI and detected significant differences in sleep disturbances across the course of injury. Longitudinal studies were scarce but helped to establish the temporal relationship between sleep disturbances and TBI and isolate sleep-related mechanisms influencing TBI prognosis. Only three studies reported on interventions for improving sleep quality and TBI symptoms. Systematic research testing assessments and interventions that target sleep disturbances for improving sleep, TBI symptoms, and long-term functional outcomes were identified as critical knowledge gaps. Findings unequivocally establish that sleep disturbances are highly prevalent in SMs and veterans with TBI. However, studies testing the effectiveness of treatments for improving sleep in military groups with TBI have been limited and their results inconsistent. This review highlights a critical opportunity for advancing military medicine through future research aimed at identifying and testing sleep-focused treatments in SMs and veterans with combat-related TBI.

Retraction Note: A mathematical model to study the relationship between the dietary profiles, core body temperature and sleep profile in the high school students

The editors have retracted in the original article because they remain unconvinced by the provenance, ownership and reliability of the data that the authors claim to have collected using the application ‘myCircadianClock’ within this study

The dual orexinergic receptor antagonist DORA-22 improves the sleep disruption and memory impairment produced by a rodent insomnia model.

Insomnia-related sleep disruption can contribute to impaired learning and memory. Treatment of insomnia should ideally improve the sleep profile while minimally affecting mnemonic function, yet many hypnotic drugs (e.g. benzodiazepines) are known to impair memory. Here, we used a rat model of insomnia to determine whether the novel hypnotic drug DORA-22, a dual orexin receptor antagonist, improves mild stress-induced insomnia with minimal effect on memory. Animals were first trained to remember the location of a hidden platform (acquisition) in the Morris Water Maze and then administered DORA-22 (10, 30, or 100 mg/kg doses) or vehicle control. Animals were then subjected to a rodent insomnia model involving two exposures to dirty cages over a 6-hr time period (at time points 0 and 3 hr), followed immediately by a probe trial in which memory of the water maze platform location was evaluated. DORA-22 treatment improved the insomnia-related sleep disruption-wake was attenuated and NREM sleep was normalized. REM sleep amounts were enhanced compared with vehicle treatment for one dose (30 mg/kg). In the first hour of insomnia model exposure, DORA-22 promoted the number and average duration of NREM sleep spindles, which have been previously proposed to play a role in memory consolidation (all doses). Water maze measures revealed probe trial performance improvement for select doses of DORA-22, including increased time spent in the platform quadrant (10 and 30 mg/kg) and time spent in platform location and number of platform crossings (10 mg/kg only). In conclusion, DORA-22 treatment improved insomnia-related sleep disruption and memory consolidation deficits.

Absence of Relationship Between Self-Reported Sleep Measures and Amyloid Load in Elderly Subjects.

Objective: To determine the relationships between self-reported sleep profile and cortical amyloid load in elderly subjects without dementia.Methods: This cross-sectional study included 143 community-dwelling participants aged ≥70 years (median: 73 years [70–85]; 87 females) with spontaneous memory complaints but dementia-free. Sociodemographic characteristics, health status, neuropsychological tests, sleep, and 18F-florbetapir (amyloid) PET data were collected. The clinical sleep interview evaluated nighttime sleep duration, but also daytime sleep duration, presence of naps, and restless leg syndrome (RLS) at time of study. Validated questionnaires assessed daytime sleepiness, insomnia, and risk of sleep apnea. The cortical standardized uptake value ratio (SUVr) was computed across six cortical regions. The relationship between sleep parameters and SUVr (cut-off ratio>1.17 and tertiles) was analyzed using logistic regression models.Results: Amyloid-PET was positive in 40.6% of participants. Almost 40% were at risk for apnea, 13.5% had RLS, 35.5% insomnia symptoms, 22.1% daytime sleepiness, and 18.8% took sleep drugs. No significant relationship was found between positive amyloid PET and nighttime sleep duration (as a continuous variable, or categorized into <6; 6–7; ≥7 h per night). Logistic regression models did not show any association between SUVr and daytime sleep duration, 24-h sleep duration, naps, RLS, daytime sleepiness, insomnia symptoms, and sleep apnea risk (before and after adjustment for APOEε4 and depressive symptoms).Conclusion: Our study did not confirm the association between amyloid-PET burden, poor sleep quantity/quality in elderly population, suggesting that the interplay between sleep, and amyloid is more complex than described.

Social media use and adolescent sleep patterns: cross-sectional findings from the UK millennium cohort study

ObjectivesThis study examines associations between social media use and multiple sleep parameters in a large representative adolescent sample, controlling for a wide range of covariates.DesignThe authors used cross-sectional data from...

Focusing on insomnia symptoms to better understand depression: A STAR*D report

BackgroundDisturbed sleep is a core symptom of major depressive disorder (MDD), with nearly 90% of those with MDD reporting disturbed sleep. However, combining insomnia and hypersomnia into a single diagnostic domain ignores distinct biological differences between those symptom presentations. To better understand depression it may be necessary to explore these symptoms independently, beginning with the more prevalent insomnia. MethodThe present study evaluated global insomnia symptom severity in a broad sample of MDD outpatients from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial, excluding patients who reported hypersomnia symptoms. The three insomnia-related symptoms from the 16-item Quick Inventory of Depressive Symptomatology- clinician rated (QIDS-C) were combined to create a global insomnia score to classify baseline insomnia severity. A modified depression severity score was then used to assess depression severity (mQIDS-C), excluding sleep-related items. ResultsA repeated measures ANCOVA revealed a significant improvement in insomnia score over the acute phase treatment (F = 33.1, d.f. = 6, 9897, p < 0.0001). Improvement in insomnia score over the acute phase treatment remained statistically significant even after controlling for change in depression severity (p = 0.0004). Participants with one point higher insomnia score at baseline were significantly less likely to remit at study exit (odds ratio = 0.88, 95% confidence interval = 0.85, 0.92, p < 0.0001) even after controlling for baseline depression severity. LimitationsObjective confirmation of sleep profiles was not available. ConclusionGreater severity of insomnia reduces likelihood of MDD remission, and insomnia symptoms improved independent of depression remission.

Relationships between objectives sleep parameters and brain amyloid load in subjects at risk for Alzheimer's disease: the INSIGHT-preAD Study.

Sleep changes have been associated with increased risks of developing cognitive disturbances and Alzheimer's disease (AD). A bidirectional relation is underlined between amyloid-beta (Aß) and sleep disruptions. The sleep profile in participants at risk to develop AD is not fully deciphered. We aim to investigate sleep-wake changes with objective sleep measurements in elderly participants without cognitive impairment depending on their brain amyloid status, positive (Aß+) or negative (Aß-) based on standard absorption ratios (SUVr) positron emission tomography-florbetapir imaging. Sixty-eight participants without cognitive impairment who have accepted to be involved in the sleep ancillary study from the InveStIGation of Alzheimer's Predictors in Subjective Memory Complainers (INSIGHT-pre AD) cohort, aiming to record sleep profile based on the analyses of an ambulatory accelerometer-based assessment (seven consecutive 24-hour periods). Neuropsychological tests were performed and sleep parameters have been individualized by actigraph. Participants also underwent a magnetic resonance imaging scan to assess their hippocampal volume. Based on SUVr PET-florbetapir imaging, two groups Aß+ and Aß- were compared. Participants were divided into two groups: Aß+ (n = 24) and Aß- (n = 44). Except for the SUVr, the two subgroups were comparable. When looking to sleep parameters, increased sleep latency, sleep fragmentation (wake after sleep onset [WASO] score and awakenings) and worst sleep efficiency were associated with cortical brain amyloid load. Actigraphic sleep parameters were associated with cortical brain amyloid load in participants at risk to develop AD. The detection of sleep abnormalities in those participants may be of interest to propose some preventive strategies.

Are sleep patterns influenced by race/ethnicity - a marker of relative advantage or disadvantage? Evidence to date.

Sleep is a fundamental necessity of life. However, sleep health and sleep disorders are not equitably distributed across racial/ethnic groups. In fact, growing research consistently demonstrates that racial/ethnic minorities are more likely to experience, for instance, shorter sleep durations, less deep sleep, inconsistent sleep timing, and lower sleep continuity in comparison to Whites. However, racial/ethnic disparities in reports of sleepiness and sleep complaints are inconsistent. Racial/ethnic groups have significant heterogeneity, yet within-group analyses are limited. Among the few published within-group analyses, there are differences in sleep between non-US-born and US-born racial/ethnic groups, but the group with the more favorable sleep profile is consistent for non-US-born Latinos compared to US-born Latinos and Whites but unclear for other racial/ethnic minority groups. These sleep health disparities are a significant public health problem that should garner support for more observational, experimental, intervention, and policy/implementation research. In this review, we 1) summarize current evidence related to racial/ethnic disparities in sleep health and within-group differences, focusing on the sleep of the following racial/ethnic minority categories that are defined by the United States Office of Management and Budget as: American Indian/Alaska Native, Asian, African American/Black, Hispanic/Latino, and Native Hawaiian/Pacific Islander; 2) discuss measurement challenges related to investigating sleep health disparities; 3) discuss potential contributors to sleep health disparities; 4) present promising interventions to address sleep health disparities; and 5) discuss future research directions on intersectionality and sleep health.