Greater Wake After Sleep Onset Research Articles

The association between timing of dietary macronutrient and sodium consumption and sleep duration and quality.

The objective of this study was to examine the association between the timing of dietary macronutrients and sodium intake and sleep quantity and quality. This was a cross-sectional study that included 34 adults between 21 and 50 years of age. The main outcome measures were objective sleep measures assessed from three nights of wrist actigraphy including sleep duration, fragmentation, and wake after sleep onset (WASO), and one night of polysomnography (PSG), including rapid eye movement (REM) sleep, non-REM stage 2 (N2), stage 3 (N3), and WASO. Multiple linear regression models and linear mixed models were used to estimate the associations between sleep measures and dietary measures (carbohydrates, fats, saturated fats, proteins, and sodium). Dietary timing was examined in two ways: (1) the average amount of each nutrient consumed within 3 hours of sleep start, and (2) the interval between the final intake of each nutrient and sleep. Average fat intake within 3 hours of sleep was associated with greater WASO from PSG (β = 4.48, p = 0.01). No other associations were found between the macronutrients or sodium intake (p > 0.05) within 3 hours of sleep and the sleep parameters from PSG or actigraphy. Similarly, no associations were found between any of the PSG or actigraphy sleep measures and the interval between final nutrient intakes and sleep with sleep duration. The study suggests that greater fat but not carbohydrate, protein, saturated fat, or sodium intake close to sleep may be associated with greater sleep disruption; however, no other associations were observed.

Are parent-reported sleep logs essential? A comparison of three approaches to guide open source accelerometry-based nocturnal sleep processing in children.

We examined the comparability of children's nocturnal sleep estimates using accelerometry data, processed with and without a sleep log. In a secondary analysis, we evaluated factors associated with disagreement between processing approaches. Children (n = 722, age 5-12 years) wore a wrist-based accelerometer for 14 days during Autumn 2020, Spring 2021, and/or Summer 2021. Outcomes included sleep period, duration, wake after sleep onset (WASO), and timing (onset, midpoint, waketime). Parents completed surveys including children's nightly bed/wake time. Data were processed with parent-reported bed/wake time (sleep log), the Heuristic algorithm looking at Distribution of Change in Z-Angle (HDCZA) algorithm (no log), and an 8 p.m.-8 a.m. window (generic log) using the R-package 'GGIR' (version 2.6-4). Mean/absolute bias and limits of agreement were calculated and visualised with Bland-Altman plots. Associations between child, home, and survey characteristics and disagreement were examined with tobit regression. Just over half of nights demonstrated no difference in sleep period between sleep log and no log approaches. Among all nights, the sleep log approach produced longer sleep periods (9.3 min; absolute mean bias [AMB] = 28.0 min), shorter duration (1.4 min; AMB = 14.0 min), greater WASO (11.0 min; AMB = 15.4 min), and earlier onset (13.4 min; AMB = 17.4 min), midpoint (8.8 min; AMB = 15.3 min), and waketime (3.9 min; AMB = 14.8 min) than no log. Factors associated with discrepancies included smartphone ownership, bedroom screens, nontraditional parent work schedule, and completion on weekend/summer nights (range = 0.4-10.2 min). The generic log resulted in greater AMB among sleep outcomes. Small mean differences were observed between nights with and without a sleep log. Discrepancies existed on weekends, in summer, and for children with smartphones and screens in the bedroom.

0876 Sleep and Body Mass Index: The Enduring Effects of Sleep Duration and Wake After Sleep Onset in College Students

Abstract Introduction College students are an at-risk population for poor sleep health and higher body mass index (BMI), which are both linked to negative health outcomes later in life. Most studies examining the relationship between sleep and BMI are cross-sectional or have collected self-reported sleep data. Therefore, the current study aimed to examine the longitudinal relationship between an objective measure of sleep assessed with a Phillips Respironics Actiwatch 2 device and BMI in college students. It was hypothesized that poorer sleep health would be related to higher BMI. Methods At three time points across the first two years of college (i.e., 8 months apart), participants (N=116) wore an Actiwatch 2 device for one week and had their height and weight measured. The sample demographics were 71% female, 72% White or Caucasian, and an average BMI of 24.07. Sleep health was defined by sleep duration, wake after sleep onset (WASO), sleep fragmentation, and midpoint of sleep. Each variable was scored as weekday (Sunday to Thursday) or weekend (Friday and Saturday). Results A linear mixed effects model using R was conducted after a person-mean variable (between person) and a person-mean centered variable (within person) were created for each participant. Weekday person-mean sleep duration was negatively related to BMI (t = -2.81), indicating shorter sleep duration was related to higher BMI across time. After controlling for between person effects, there were enduring relationships between both person-mean centered sleep duration (t = -3.12) and WASO (t = 2.06) and BMI, indicating that shorter sleep duration and greater WASO was related to higher BMI within participants across time. No significant relationships were found between weekend sleep variables and BMI. Conclusion The current findings add to a growing literature indicating that poor sleep health is related to increased BMI. In particular, the findings indicate that shorter sleep duration and greater WASO may increase risk for weight gain across time but are specific to weekday sleep behaviors. Although alterations in biological and behavioral processes likely serve as the mechanisms by which these variables influence BMI, additional research is needed to understand how this occurs and why weekday sleep behaviors are particularly important. Support (if any)

Getting a Good Night's Sleep: Associations Between Sleep Duration and Parent-Reported Sleep Quality on Default Mode Network Connectivity in Youth

PurposeSleep plays an important role in healthy neurocognitive development, and poor sleep is linked to cognitive and emotional dysfunction. Studies in adults suggest that shorter sleep duration and poor sleep quality may disrupt core neurocognitive networks, particularly the default mode network (DMN)—a network implicated in internal cognitive processing and rumination. Here, we examine the relationships between sleep and within- and between-network resting-state functional connectivity (rs-FC) of the DMN in youth. MethodsThis study included 3,798 youth (11.9 ± 0.6 years, 47.5% female) from the Adolescent Brain Cognitive Development cohort. Sleep duration and wake after sleep onset (WASO) were quantified using Fitbit watch recordings, and parent-reported sleep disturbances were measured using the Sleep Disturbance Scale for Children. We focused on rs-FC between the DMN and anticorrelated networks (i.e., dorsal attention network [DAN], frontoparietal network, salience network). ResultsBoth shorter sleep duration and greater sleep disturbances were associated with weaker within-network DMN rs-FC. Shorter sleep duration was also associated with weaker anticorrelation (i.e., higher rs-FC) between the DMN and two anticorrelated networks: the DAN and frontoparietal network. Greater WASO was also associated with DMN-DAN rs-FC, and the effects of WASO on rs-FC were most pronounced among children who slept fewer hours/night. DiscussionTogether, these data suggest that different aspects of sleep are associated with distinct and interactive alterations in resting-state brain networks. Alterations in core neurocognitive networks may confer increased risk for emotional psychopathology and attention-related vulnerabilities. Our findings contribute to the growing number of studies demonstrating the importance of healthy sleep practices in youth.

Associations Between Objectively Measured Sleep and Cognition: Main Effects and Interactions With Race in Adults Aged ≥50 Years.

This study examined associations of actigraphy-estimated sleep parameters with concurrent and future cognitive performance in adults aged ≥ 50 years and explored interactions with race. Participants were 435 cognitively normal adults in the Baltimore Longitudinal Study of Aging who completed wrist actigraphy at baseline (mean = 6.6 nights) and underwent longitudinal testing of memory, attention, executive function, language, and visuospatial ability. On average, participants with follow-up data were followed for 3.1 years. Primary predictors were baseline mean total sleep time, sleep onset latency, sleep efficiency (SE), and wake after sleep onset (WASO). Fully adjusted linear mixed-effects models included demographics, baseline health-related characteristics, smoking status, sleep medication use, APOE e4 carrier status, and interactions of each covariate with time. In adjusted models, higher SE (per 10%; B = 0.11, p = .012) and lower WASO (per 30 minutes; B = -0.12, p = .007) were associated with better memory cross-sectionally. In contrast, higher SE was associated with greater visuospatial ability decline longitudinally (B = -0.02, p = .004). Greater WASO was associated with poorer visuospatial ability cross-sectionally (B = -0.09, p = .019) but slower declines in visuospatial abilities longitudinally (B = 0.02, p = .002). Several sleep-cognition cross-sectional and longitudinal associations were stronger in, or limited to, Black participants (compared to White participants). This study suggests cross-sectional sleep-cognition associations differ across distinct objective sleep parameters and cognitive domains. This study also provides preliminary evidence for racial differences across some sleep-cognition relationships. Unexpected directions of associations between baseline sleep and cognitive performance over time may be attributable to the significant proportion of participants without follow-up data and require further investigation.

0113 Daily Patterns of Sleep and Metacognition in College Students

Abstract Introduction Sleep problems have been associated with subjective cognitive complaints (a type of metacognition) in older adults, but little research has examined if this same relationship exists in younger adults. Additionally, college students have high intra-individual variability with their sleep, making day-to-day sleep an understudied parameter of interest in this population. Considering that metacognition has been associated with academic outcomes (e.g., GPA) in college students, it is important to understand how daily sleep patterns might impact metacognition. The present study examined how intra-individual variability in sleep is associated with metacognitive ratings in college students. Methods College students (N=81, Mage=18.8, SD = 1.1, 64 females) completed seven days of sleep diaries reporting total sleep time (TST), sleep onset latency (SOL), number of nighttime awakenings, and wake after sleep onset (WASO). Students also provided morning metacognitive ratings regarding the perceived quality of mental functioning from very poor (0) to very good (100). Multilevel modeling analyses tested whether intraindividual variability in daily sleep variables was associated with daily metacognitive ratings, after controlling for interindividual sleep patterns, age, sex, sleep medication usage, and anxiety symptoms (via the Hospital Anxiety and Depression Scale). Results Daily TST was associated with metacognitive ratings (B=2.35, p=0.003), in that those who slept less than their typical average reported worse metacognitive ratings. Similarly, daily number of nighttime awakenings (B=-1.92, p=0.02) and WASO (B=-0.13, p=0.009) were also associated with metacognitive ratings, in that those with more awakenings and greater WASO than their typical average reported worse metacognitive ratings. Conclusion Findings suggest that deviation in typical daily sleep patterns (shorter TST, a greater number of nighttime awakenings, greater WASO) may impact daily metacognitive ratings in college students. Similar patterns are not observed at the average/interindividual level, prompting the need for future studies to examine daily sleep in college students. These findings point to the need for research examining whether sleep interventions (e.g., Cognitive Behavioral Therapy for Insomnia) for college students who experience sleep variability, could improve metacognition, which in turn could improve academic outcomes. Support (If Any)

0148 Associations Between Subjective and Objective Sleep Outcomes and Nightly Pain Changes in a Chronic Pain Sample

Abstract Introduction Patients with chronic pain often experience poor sleep. Research demonstrating the bidirectional nature of the pain/sleep association has focused on interindividual patterns based on between person averages, leaving acute, intraindividual patterns based on night-to-night fluctuations understudied. Because both pain and sleep fluctuate considerably, better understanding of those fluctuations may provide important insight into the pain/sleep relationship. Here we examine inter- and intraindividual associations between subjective and objective sleep outcomes and nightly pain changes in individuals with chronic pain and sleep complaints. Methods Adults with chronic pain and sleep complaints (n=169, Mage=52, SD= 12, 95% female) completed 14 days of actigraphy and sleep diaries each morning and evening. Evening diaries recorded pain and sleep medication use (yes/no), and evening pain intensity (0-none, 100-most intense). Actigraphy and morning diaries recorded sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and morning pain intensity (0-none, 100-most intense). A nightly pain difference score (morning – evening) was calculated, where positive values indicate worse morning pain relative to previous evening pain. Multi-level models examined the inter- and intraindividual associations between sleep (subjective and objective SOL, WASO, TST) and nightly pain difference scores. Analyses controlled for age, sleep, and pain medication use. Results Greater interindividual subjective WASO was associated (B=0.06, SE=0.03, p=0.02) with greater interindividual pain difference scores. Other interindividual sleep outcomes (subjective and objective) were not significantly associated with interindividual pain difference scores. There were no associations between sleep outcomes (subjective and objective) and pain difference scores at the intraindividual level. Conclusion Findings show sleep and pain were not linked at the daily, intraindividual level. However, on average, greater WASO was linked with worse morning relative to evening pain. Thus, although a single night of poor sleep may not impact pain, the buildup of fragmented sleep over time may interfere with restorative properties of sleep and exacerbate morning pain. Future work should investigate mechanisms underlying sleep fragmentation (e.g., sleep architecture, physiological arousal) and how such factors relate to nightly pain changes. Support (If Any) NIH/NIAMS R01AR055160, ClinicalTrials-NCT02001077, PI McCrae.

0332 Objective and subjective sleep quality in Mexican Americans and non-Hispanic Whites: the HABLE-Dormir Study

Abstract Introduction The ongoing prospective Health & Aging Brain among Latino Elders (HABLE)-Dormir Study is designed to investigate the association between objective and subjective sleep quality and cognitive impairment among Mexican Americans and non-Hispanic Whites (NHWs). Methods We plan to recruit 1000 community-dwelling Mexican Americans and NHWs and elders (age 50 and above). Objective sleep duration and fragmentation were assessed by 7-day wrist actigraphy; presence of sleep disordered breathing (SDB) was determined using WatchPAT; and subjective sleep quality and excessive daytime sleepiness (EDS) were examined by Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), respectively. Results To date, 367 participants have been enrolled (62% women, 45% Mexican Americans, mean age 67.3±8.4 years); 296 (81%) of the participants had normal cognition, 56 (15%) had mild cognitive impairment (MCI), and 15 (4%) had dementia. On average, participants had a mean sleep duration of 7.3±1.1 hours, sleep efficiency of 88.3±5.3%, and wake after sleep onset (WASO) of 55.2±29.3 minutes. Almost half (51%) of the participants had moderate to severe SDB defined by WatchPAT-derived respiratory event index (REI) >=15, 54% had self-reported poor sleep quality (PSQI>5), and 10% reported EDS (ESS>=11). After adjustment for age, Mexican Americans had lower sleep efficiency (86.5% vs. 89.5%, p<0.001) and greater WASO (63.6 vs. 48.9 minutes, p<0.001), compared to NHWs. Sleep duration did not differ significantly among NHWs (7.2 hours) and Mexican Americans (7.4 hours); p=0.20. The prevalence of moderate to severe SDB was similar in NHWs (51.2%) and Mexican Americans (50.0%); p=0.84. Besides, NHWs and Mexican Americans had similar PSQI and prevalence of EDS. Conclusion In this initial analysis, Mexican Americans have worse objective sleep quality, but similar sleep duration, prevalence of SDB and subjective sleep quality as compared to NHWs. Continued investigations are needed to explore potential racial/ethnic disparities in sleep health and how differences in objective and subjective measurements vary by race and ethnicity. Support (If Any)

Temporal Associations Between Daytime Napping and Nocturnal Sleep: An Exploration of Random Slopes.

Restricting daytime naps is a common sleep hygiene recommendation to improve nocturnal sleep, but research on whether napping is related to sleep is mixed. The current literature is limited in that day level, bidirectional associations have not been tested in college students, and existing studies have not sufficiently examined the role of individual differences in these daily associations. The current study addressed these limitations by assessing the temporal associations between self-reported daytime nap duration and objectively assessed nocturnal sleep, and whether these associations were moderated by chronotype or nap frequency, in college students. Participants (N = 384) self-reported nap duration and wore an actiwatch to measure nocturnal sleep for 14 consecutive days and nights. Mixed linear models were used to test the daily associations between daytime nap duration and total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). In addition, random slope modeling was used to test whether these associations significantly varied between participants. Longer nap duration was significantly associated with greater WASO, lower SE, and longer SOL. Shorter TST, shorter WASO, and greater SE were related to longer next-day nap duration. There were several significant associations between daytime napping and nocturnal sleep, and nap frequency significantly moderated the association between TST and next-day nap duration. Future research should test daily and contextual moderators of daytime napping and nocturnal sleep, which could refine sleep hygiene efforts by identifying individuals for whom recommendations would be most helpful.

Objectively measured sleep and physical function: Associations in low-income older adults with disabilities

ObjectiveLate-life sleep health has been tied to physical function, but little is known about these associations among socially disadvantaged populations. DesignWe determined cross-sectional associations of sleep with physical function in low-income, predominantly Black older adults with disabilities. ParticipantsOne hundred thirty-six older adults (mean age 76.0 years, 83.8% women, 82.4% Black). MeasurementsPrimary predictors were actigraphic total sleep time (TST), wake after sleep onset (WASO), and subjective sleep complaints. Outcomes were objective physical performance (Short Physical Performance Battery (SPPB)) and participant-reported difficulties in basic and instrumental activities of daily living (ADLs and IADLs). ResultsIn regression models adjusted for potential confounders, both longer TST and greater WASO were associated with lower SPPB scores and increased IADL difficulty. Participants with a mean TST in the longest (>7.5 hours) vs. intermediate (6.3-7.5 hours) tertile had 27% higher odds of additional IADL difficulty (incident rate ratio = 1.27, 95% confidence interval [CI] 1.03, 1.58). Each additional 10 minutes of WASO was associated with 0.13 point lower SPPB scores (B = −0.13, 95% CI −0.25, −0.01) and increased IADL difficulty (B = 0.02, 95% CI 0.0003, 0.04). Sex moderated the associations of WASO with IADL and ADL difficulties: associations were stronger for males. Subjective sleep complaints were not statistically significantly associated with function. ConclusionsAmong disabled, low-income, mostly Black older adults, objective measures of long sleep and greater WASO are associated with poorer physical function. Effect sizes for the associations were modest; however, findings may have important implications given the significant consequences of decreased function on quality of life and caregiving demands.

Digital phenotyping of sleep patterns among heterogenous samples of Latinx adults using unsupervised learning

ObjectiveThis study aimed to identify sleep disturbance subtypes (“phenotypes”) among Latinx adults based on objective sleep data using a flexible unsupervised machine learning technique. MethodsThis study was an analysis of sleep data from three cross-sectional studies of the Precision in Symptom Self-Management Center at Columbia University. All studies focused on sleep health in Latinx adults at increased risk for sleep disturbance. Data on total sleep time (TST), time in bed (TIB), wake after sleep onset (WASO), sleep efficiency (SE), number of awakenings (NOA) and the mean length of nightly awakenings were collected using wrist-mounted accelerometers. Cluster analysis of the sleep data was conducted using an unsupervised machine learning approach that relies on mixtures of multivariate generalized linear mixed models. ResultsThe analytic sample included 494 days of data from 118 adults (Ages 19–77). A 3-cluster model provided the best fit based on deviance indices (ie, DΔ∼ −75 and −17 from 1- and 2- to 3-cluster models, respectively) and likelihood ratio (Pdiff ∼ 0.93). Phenotype 1 (n = 64) was associated with greater likelihood of overall adequate SE and less variability in SE and WASO. Phenotype 2 (n = 11) was characterized by higher NOAs, and greater WASO and TIB than the other phenotypes. Phenotype 3 (n = 43) was characterized by greater variability in SE, bed times and awakening times. ConclusionRobust digital data-driven modeling approaches can be useful for detecting sleep phenotypes from heterogenous patient populations, and have implications for designing precision sleep health strategies for management and early detection of sleep problems.

648 Associations between objective afternoon and evening physical activity and polysomnographic sleep in fibromyalgia

Abstract Introduction Patients with fibromyalgia (FM) suffer from pain which limits physical activity and disrupts sleep. Research examining the relationship between pre-bedtime physical activity, pain, and objective sleep is limited. This study examined whether objectively measured activity levels (via actigraphy), pain intensity, or their interaction are associated with polysomnographic sleep outcomes and sleep architecture. Methods Adults with FM (n=158, Mage=52, SD=12, 93% female) completed 14 daily pain ratings, 14 days of actigraphy, and a single night of polysomnography. Activity levels (i.e., magnitude of wrist motion captured per 30 second epoch) were recorded, and average afternoon/evening activity for intervals 12:00-15:00, 15:00-18:00, and 18:00-21:00 was computed, removing days in which participants slept during these periods. Sleep architecture was quantified as the percentage of sleep time in rapid eye movement (%rem) and non-rem (i.e. %stage 1, %stage 2, and %stage 3). Multiple regressions examined whether average afternoon/evening activity, average evening pain [0 (no pain)–100 (most intense pain imaginable)], or their interaction predicted polysomnographic sleep onset latency (SOL), wake after sleep onset (WASO), sleep efficiency (SE), %stage 1, %stage 2, %stage 3, and %rem, controlling for age, body mass index, average individual bedtime, time in bed, and sleep or pain medication usage. Results Greater afternoon activity from 12:00-15:00 was independently associated with lower SE (B= -.08, p=.01), greater WASO (B=.45, p<.001), and greater %stage 1 (B=.04, p<.01). Pain intensity interacted with physical activity from 12:00-15:00 such that the association between physical activity and higher WASO (p=.05) and greater %stage 1 (p<.01) was stronger for individuals with higher pain. Pain intensity and activity from 15:00-18:00, and 18:00-21:00 were not associated with sleep outcomes. Conclusion Our results suggest greater afternoon activity is associated with greater polysomnographic sleep fragmentation and greater %stage 1 sleep in FM, and these relationships are stronger for individuals with higher pain. These relationships are consistent with activity pacing recommendations for chronic pain and suggest pacing in the afternoon may be important for good sleep in FM. However, future research examining causal pathways linking physical activity levels and timing, pain, and sleep is needed. Support (if any) Support: NIAMS (R01AR055160/R01AR005160- S1;PI McCrae). Data collected at University of Florida (Clinical Trial-NCT02001077;PI McCrae).

Physical activity, sedentary time and sleep in cystic fibrosis youth: A bidirectional relationship?

Physical activity (PA) and sleep are highly important for those with cystic fibrosis (CF), yet, despite this and suggestions of a bidirectional relationship between these factors in healthy children, their relationship is yet to be investigated. PA, sedentary time (SED), and sleep were objectively derived over seven days in 58 youth (11.9 ± 2.7 years; 29 CF). Generalized linear latent and mixed models with a random intercept and slope at child-level were adjusted for age, sex, wear-time, type of day, group and mean PA/SED and sleep. Every additional 10 min sedentary was associated with 5.6 and 5.0 min less sleep and 10.6 and 12.0 min less wake after sleep onset (WASO) that night, in CF and healthy children, respectively. PA, regardless of intensity, was not associated with total sleep time but every additional 10 min of light PA (LPA) was associated with 3.0 min less WASO in healthy participants. Ten mins more sleep was associated with 3.1 and 1.7 min less SED in CF and healthy children, respectively. In CF, greater sleep time led to less LPA (3.6 min) the following day, whereas, in healthy children, poor sleep quality (greater WASO) was associated with more LPA (1.4 min) and moderate-to-vigorous PA (5.2 min) the following day. A bidirectional relationship between SED and subsequent total sleep time was evident, irrespective of group, whereas the relationship between sleep and PA was group dependent. These findings have important implications regarding the reciprocal effects of promoting PA or sleep quantity or quality.

Effect of exercise on sleep and bi-directional associations with accelerometer-assessed physical activity in men with obesity.

This study examined the effect of exercise training on sleep duration and quality and bidirectional day-to-day relationships between physical activity (PA) and sleep. Fourteen inactive men with obesity (age: 49.2 ± 7.9 years, body mass index: 34.9 ± 2.8 kg/m2) completed a baseline visit, 8-week aerobic exercise intervention, and 1-month post-intervention follow-up. PA and sleep were assessed continuously throughout the study duration using wrist-worn accelerometry. Generalised estimating equations were used to examine associations between PA and sleep. Sleep duration increased from 5.2 h at baseline to 6.6 h during the intervention period and 6.5 h at 1-month post-intervention follow-up (p < 0.001). Bi-directional associations showed that higher overall activity volume and moderate-to-vigorous physical activity (MVPA) were associated with earlier sleep onset time (p < 0.05). Later timing of sleep onset was associated with lower overall volume of activity, most active continuous 30 min (M30CONT), and MVPA (p < 0.05). Higher overall activity volume, M30CONT, and MVPA predicted more wake after sleep onset (WASO) (p < 0.001), whereas greater WASO was associated with higher overall volume of activity, M30CONT, and MVPA (p < 0.001). An aerobic exercise intervention increased usual sleep duration. Day-to-day, more PA predicted earlier sleep onset, but worse sleep quality and vice versa. Novelty: Greater levels of physical activity in the day were associated with an earlier sleep onset time that night, whereas a later timing of sleep onset was associated with lower physical activity the next day in men with obesity. Higher physical activity levels were associated with worse sleep quality, and vice versa.

Associations between sleep and cognitive performance in a racially/ethnically diverse cohort: the Study of Women's Health Across the Nation.

To determine whether actigraphy-assessed indices of sleep are associated with cognitive performance in women, and explore whether these associations vary by race/ethnicity. Participants were 1,126 postmenopausal community-dwelling females (mean age 65 years) from the observational Study of Women's Health Across the Nation (SWAN); 25% were black, 46% white, 13% Chinese, 11% Japanese, and 5% Hispanic. Actigraphy-assessed sleep measures included total sleep time, wake after sleep onset (WASO), and fragmentation. Cognitive measures included immediate and delayed verbal memory, working memory, and information processing speed. All measures were assessed in conjunction with SWAN annual visit 15. Across the sample, after covariate adjustment, greater WASO and fragmentation were concurrently associated with slower information processing speed. Black participants had significantly worse sleep relative to other race/ethnic groups. Significant race/sleep interactions were observed; in black, but not white, participants, greater fragmentation was concurrently associated with worse verbal memory and slower information processing speed, and greater WASO was concurrently associated with slower information processing speed. Sleep-cognitive performance associations were not different in Chinese and Japanese participants relative to white participants. Greater wakefulness and fragmentation during sleep are concurrently associated with slower information processing. Sleep continuity impacted concurrent cognitive performance in black, but not white, women. This effect may not have been detected in white women because their sleep was largely within the normal range. Future longitudinal studies in diverse samples are critical to further understand whether race/ethnicity moderates the influence of sleep on cognitive performance.

Effects of Brief Behavioral Treatment for Insomnia on Daily Associations between Self-Reported Sleep and Objective Cognitive Performance in Older Adults

ABSTRACT Objective Behavioral treatments for insomnia improve sleep in older adults, but research documenting their effects on cognitive performance is mixed. We explored whether a brief behavioral treatment for insomnia (BBTi) impacts daily associations between sleep parameters and next day cognition. Methods Sixty-two older adults (Mage = 69.45 years, SD = 7.71) with insomnia completed either 4 weeks of BBTi or self-monitoring control (SMC). At baseline, post-treatment, and 3 month follow-up, participants completed 14 days of diaries measuring sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE), as well as daily cognitive tests measuring processing speed (i.e., symbol digit modalities test, SDMT), and reasoning (i.e., letter series). At each time period, associations between sleep parameters and daily cognition, controlling for age, education, insomnia duration, use of sleep medications, and depression (i.e., Beck Depression Inventory–2nd Edition scores), were examined through multilevel modeling. Results At post-treatment, we observed an interactive fixed effect of treatment condition (i.e., BBTi/SMC) and TST on daily SDMT and letter series performance. For BBTi, longer TST was associated with better letter series performance, and did not predict SDMT performance. For SMC, longer TST was associated with worse SDMT, and was not associated with letter series performance. Greater WASO (regardless of group) was associated with better SDMT performance at post-treatment. Associations were not maintained at follow-up. Conclusions Sleep duration may play an important role in BBTi-related improvements in daily higher order cognition. Maintenance of these associations may be facilitated by booster sessions following post-treatment. Clinical Trial Identifier NCT02967185

Acute Exercise Alters Brain Activation In Older Adults: What Is The Role Of Sleep?

Insufficient sleep is associated with altered brain activation and poor cognitive performance. Aerobic exercise training enhances neural efficiency and improves cognition. PURPOSE: To examine sleep’s role in the effect of acute aerobic exercise on brain functional activation and cognitive performance. METHODS: We studied healthy, physically active older adults (n = 31; mean age = 66.2 ± 7.4 years (range = 55-81); 74.2% women; 93.6% > high school education; body mass index = 25.7 ± 4.2). During two counterbalanced study visits, participants engaged in 30 minutes of moderate-intensity bicycle exercise or seated rest, followed by a functional MRI scan. While in the scanner, participants completed the Erikson Flanker Task. Prior to the first study visit they also completed 7.9 ± 3.3 nights of wrist actigraphy. Actigraphic sleep indices included total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), and average wake bout length (WBL). RESULTS: Compared to rest, acute exercise significantly increased functional activation in the right superior parietal lobule (SPL; beta = 0.14, p = 0.011) and decreased activation in the left anterior cingulate cortex (ACC; beta = -0.09, p = 0.012). After adjustment for age, sex, race, and education, greater WASO was associated with less exercise-induced change in SPL activation (beta = -0.05, p = 0.001). There were no significant associations between TST, SE, or WBL and exercise-induced changes in functional activation. Acute exercise did not significantly affect Flanker Task performance. CONCLUSIONS: Acute moderate-intensity exercise alters functional activation in brain regions involved in executive function and inhibitory control, which align with previous exercise studies showing a conflict-related shift from ACC to SPL activity. Our findings suggest that the short-term effects of acute exercise may accumulate and promote the cognitive improvements linked to exercise training. Moreover, our findings suggest that greater time awake after initial sleep onset (i.e., sleep fragmentation) may attenuate the benefits of aerobic exercise on functional activation in the aging brain. Randomized controlled trials are necessary to further evaluate the interactive effects of sleep and acute exercise in older adults.

Sleep and Glycemia in Adolescents with Type 1 Diabetes

Nearly 70% of adolescents have chronic sleep problems (quality, quantity, and/or altered circadian rhythm). Adolescents with type 1 diabetes (T1D) are subject to nocturnal blood glucose fluctuations that may result in restless sleep and require self-care that disrupts sleep. Deficient sleep may also contribute to insulin resistance. Few studies of sleep characteristics and their association with glycemic control have been conducted. Our aim was to describe sleep characteristics in adolescents with T1D and its relationship with glycemic control. Adolescents with T1D (ages 10-16) were recruited from the Yale Program. For 7 days, participants wore a wrist actigraph, which was used to calculate sleep/wake cycles using 30-second epochs, and a continuous glucose monitor (CGM). The Pittsburgh Sleep Quality Index (PSQI) was used to assess subjective sleep reports. The sample included 30 participants age 13.4+1.9, 67.9% female, 29.2% minority, BMI percentile 75+25%, diabetes duration 7.4+ 4.5 years, and 97% on insulin pumps. Hemoglobin A1c (A1c) levels (8.29+1.38%) and CGM (46.3+14.9% time in hyperglycemia) indicated poor glycemic control. Actigraphy showed inadequate total sleep time (7.33+19 hours), but good sleep efficiency (80.0+20.3%). Higher MESOR (rhythm adjusted mean) (r=0.25) and lower circadian quotient (r=-0.31) were associated with higher A1c. Greater circadian quotient was associated with more glucose variability (r=0.41). Greater WASO (wake after sleep onset) was associated with higher glucose (r=0.26), HBGI (high blood glucose index) (r=0.27), and more hyperglycemia (r=0.25). Higher MESOR was associated with lower LBGI (low blood glucose index) (r=-0.39) and less hypoglycemia (r=-0.42). Higher amplitude was associated with lower LBGI (-0.35) and less hypoglycemia (r=-0.39). These results suggest that insufficient sleep is common among adolescents with T1D and is associated with poorer glycemic control. Further research is required to determine if improving sleep will improve glycemic control. Disclosure M. Grey: None. K. Rechenberg: None.

VaPER: The Development of Spaceflight Associated Neuro‐ocular Syndrome (SANS) During Hypercapnic 6° Head‐Down Tilt Bed Rest; sans Sufficient Sleep?

OBJECTIVETo determine whether the combination of a cephalad fluid shift induced by headdown tilt (HDT) bed rest and chronic exposure to mild hypercapnia for 30 days will alter sleep architecture and circadian rhythm, contributing to characteristics of Spaceflight Associated Neuro‐ocular Syndrome (SANS).METHODSAfter 14 days of ambulatory normocapnic familiarization with the facility and baseline data collection (BDC), eleven subjects (5 female) breathed mild, ambient hypercapnia (0.5% CO2) throughout 30 days of 6° HDT at the German Aerospace Center (DLR): envihab facility. Following HDT, subjects were monitored for an additional 14 days of ambulatory, normocapnic recovery (R). Overnight polysomnography (PSG) was measured using a type‐2 sleep monitoring system, and the PSG was scored by a Polysomnographic Technologist to assess sleep duration, staging, latency, and arousals. Circadian rhythm was assessed by monitoring 24‐hour core body temperature with rectal temperature probes. Arterial PCO2 levels were estimated from transcutaneous PCO2 monitoring throughout sleep. Retinal thickness was measured via optical coherence tomography (OCT); those with increased thickness &gt;50μ in the nasal quadrant were classified as RET+, those &lt;50μ were classified as RET‐. After one night of familiarization with the instrumentation, measurements were collected at six different time points (one BDC, three HDT, and two R).RESULTSWhen comparing RET+ to RET‐, subjects had: significantly less total sleep time (TST) in BDC (345 ± 25 min vs 401 ± 23 min, p &lt; 0.05), HDT4 (303 ± 64 min vs 375 ± 20 min, p &lt; 0.05), HDT28 (344 ± 59 min vs 407 ± 32 min, p &lt; 0.05), and R+4 (344 ± 68 min vs 421 ± 21 min, p &lt; 0.05); significantly less stage 2 (N2) sleep in HDT4 (157 ± 43 min vs 220 ± 9 min, p &lt; 0.05), HDT28 (198 ± 32 min vs 256 ± 21 min, p &lt; 0.05), and R+4 (187 ± 74 min vs 271 ± 32, p &lt; 0.05); significantly more wake after sleep onset (WASO) in HDT4 (147 ± 85 min vs 57 ± 27 min, p &lt; 0.05) and R+4 (134 ± 106 min vs 41 ± 12 min, p &lt; 0.05); and a significantly reduced core body temperature amplitude at BDC (0.3 ± 0.1 deg vs 0.5 ± 0.1 deg, p &lt; 0.05), HDT4 (0.2 ± 0.1 deg vs 0.4 ± 0.1 deg, p &lt; 0.05), HDT28 (0.3 ± 0.1 deg vs 0.4 ± 0.1 deg, p &lt; 0.05), and R+10 (0.3 ± 0.0 deg vs 0.4 ± 0.1 deg, p &lt; 0.05).CONCLUSIONSPrior to and throughout the experimental conditions, when compared to RET‐, RET+ subjects were “short” sleepers and in general had less N2 sleep, greater WASO, and had a lower amplitude of core body temperature. We conclude that insufficient sleep may predispose certain individuals to the development of retinal thickening, a finding of SANS. Objective PSG may be a potential variable to consider when determining astronaut spaceflight duration.Support or Funding InformationNASA Human Research Program NNJ14ZSA001NThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

0926 CONTINUOUS GLUCOSE MONITORING, INSULIN RESISTANCE, AND SLEEP IN ADOLESCENTS WITH CYSTIC FIBROSIS

Diabetes is diagnosed in one in four adolescents with cystic fibrosis (CF) and is associated with increased morbidity and mortality, thus there is a need to identify factors affecting glucose metabolism in CF. Patients with CF have greater objective and subjective sleep problems but the relationship between sleep and metabolic function has not been fully examined. The aim of the current study was to examine the relationship between objectively measured sleep and glucose metabolism in a sample of CF youth. Forty-three participants with CF at baseline health (mean age = 13.8 years) and 13 healthy controls (mean age = 15.2 years) underwent an oral glucose tolerance test (OGTT) and one week of concurrent home continuous glucose monitoring (CGM) and actigraphy. Fasting labs included glucose, insulin, and C-peptide. Two-sample independent t-tests and ANOVA tested differences between sleep outcomes in CF vs. control participants with post-hoc Tukey’s Honestly Significant Difference test. Spearman’s rank correlation coefficients tested correlations between sleep and CGM and insulin sensitivity. Of the CF participants, 15 had normal glycemia, 17 had abnormal glycemia, and 11 had CF-related diabetes (CFRD) per OGTT. Average sleep duration for the entire sample was 7.5 hours, indicating insufficient sleep. Participants with CF had longer sleep onset latency (SOL), lower sleep efficiency (SE), and higher wake after sleep onset (WASO) than controls. Higher minimum daytime glucoses on CGM correlated negatively with total sleep time and SE. In CF youth with abnormal glycemia or diabetes, poorer insulin sensitivity (lower 1/c-peptide) was seen in those with shorter sleep duration, longer SOL, poorer SE, and greater WASO. Poor sleep was correlated with higher glucose and lower insulin sensitivity in a sample of youth with CF. Further research is needed to better understand the mechanisms behind this relationship and potential implications for treatment and management of impaired glycemia in youth with CF. CFFT grant CHAN16A0 and NIH grants 5K12DK094712-04, UL1 TR001082 (CCTSI)