Actigraphy-based Sleep Duration Research Articles

Associations of actigraphy measures of sleep duration and continuity with executive function, vigilance, and fine motor control in children with snoring and mild sleep-disordered breathing.

Children with snoring and mild sleep-disordered breathing may be at increased risk for neurocognitive deficits despite few obstructive events. We hypothesized that actigraphy-based sleep duration and continuity associate with neurobehavioral functioning and explored whether these associations vary by demographic and socioeconomic factors. 298 children enrolled in the Pediatric Adenotonsillectomy Trial, ages 3 to 12.9 years, 47.3% from racial or ethnic minority groups, with habitual snoring and an apnea-hypopnea index < 3 were studied with actigraphy (mean 7.5 ± 1.4 days) and completed a computerized vigilance task (Go-No-Go) and a test of fine motor control (9-Hole Pegboard). Caregivers completed the Behavior Rating Inventory of Executive Function. Regression analyses evaluated associations between sleep exposures (24-hour and nocturnal sleep duration, sleep fragmentation index, sleep efficiency) with the Behavior Rating Inventory of Executive Function Global Executive Composite index, pegboard completion time (fine motor control), and vigilance (d prime on the Go-No-Go), adjusting for demographic factors and study design measures. Longer sleep duration, higher sleep efficiency, and lower sleep fragmentation were associated with better executive function; each additional hour of sleep over 24 hours associated with more than a 3-point improvement in executive function (P = .002). Longer nocturnal sleep (P = .02) and less sleep fragmentation (P = .001) were associated with better fine motor control. Stronger associations were observed for boys and children less than 6 years old. Sleep quantity and continuity are associated with neurocognitive functioning in children with mild sleep-disordered breathing, supporting efforts to target these sleep health parameters as part of interventions for reducing neurobehavioral morbidity. Registry: ClinicalTrials.gov; Name: Pediatric Adenotonsillectomy for Snoring (PATS); URL: https://clinicaltrials.gov/ct2/show/NCT02562040; Identifier: NCT02562040. Robinson KA, Wei Z, Radcliffe J, etal. Associations of actigraphy measures of sleep duration and continuity with executive function, vigilance, and fine motor control in children with snoring and mild sleep-disordered breathing. J Clin Sleep Med. 2023;19(9):1595-1603.

Genetic background to attention deficit and hyperactivity disorder and attention deficit and hyperactivity disorder symptoms at the age of 5 years: the role of sleep duration.

We studied the associations between polygenic risk score (PRS) for attention deficit and hyperactivity disorder (ADHD) and (1) ADHD symptoms in 5-year-old children, (2) sleep duration throughout childhood, and (3) the interaction between PRS for ADHD and short sleep duration relative to ADHD symptoms at 5 years. This study is based on the population-based CHILD-SLEEP birth cohort (N = 1420 children). PRS was used to quantitate the genetic risk for ADHD. Parent-reported ADHD symptoms at 5 years were obtained from 714 children, using the Strengths and Difficulties Questionnaire (SDQ) and the Five-to-Fifteen (FTF). Our primary outcomes were SDQ-hyperactivity and FTF-ADHD total scores. Parent-reported sleep duration was measured at 3, 8, 18, 24 months, and 5 years in the whole sample and actigraphy-based sleep duration at 2 and 24 months in a subsample. PRS for ADHD associated with SDQ-hyperactivity (β = 0.214, p = .012) and FTF-ADHD total (β = 0.639, p = .011), and FTF-inattention and hyperactivity subscale scores (β = 0.315, p = .017 and β = 0.324, p = .030), but not with sleep duration at any time point. Significant interactions were found between high PRS for ADHD and parent-reported short sleep throughout childhood in FTF-ADHD total score (F = 4.28, p = .039) and FTF-inattention subscale (F = 4.66, p = .031). We did not find any significant interaction between high PRS for ADHD and actigraphy-based short sleep. Parent-reported short sleep moderates the association between genetic risk of ADHD and ADHD symptoms in early childhood in the general population, so that children with short sleep, in combination with high genetic risk for ADHD, could be at highest risk for ADHD symptoms.

Relationshipbetween family income and trajectories of adjustment in adolescence: Sleep and physical activity as moderators.

Youth from lower-income families experience adjustment problems at higher rates than higher-income peers. While adolescents have little control over family income, they do have some agency over their sleep and physical activity, two factors that have been shown to mitigate the risk of maladjustment. To test this, sleep and physical activity were examined as moderators of the longitudinal relationship between family income (indexed by income-to-needs ratio)and trajectories of adolescent adjustment problems. Participants included a socioeconomically diverse community sample of 252 USyouth (53% female; 33% Black, 67% White) in 2012-2015. Actigraphy-based sleep duration and quality were indexed, respectively, by minutes (sleep onset to wake excluding awakenings) and efficiency (% minutes scored as sleep from onset to wake). Physical activity and adjustment were youth-reported. Outcomes included internalizing (anxious/depressive) and rule-breaking behavior. Latent growth models estimated trajectories of adjustment across ages 16 and 18 years conditional on family income, sleep, physical activity, and their interactions. Relationships between family income and change in internalizing symptoms were moderated by sleep minutes, and associations between income and change in internalizing symptoms and rule-breaking behavior were moderated conjointly by sleep efficiency and physical activity. Under conditions of high-quality sleep and more physical activity, adolescents with lower income reported fewer adjustment problems. Conversely, youth with both poor sleep and low physical activity were at the highest risk for maladjustment over time. Findings enhance understanding of individual differences in trajectories of mental health associated with bioregulation, health behaviors, and the sociocultural context.

Sleep duration and disturbance are associated with orthostatic heart rate recovery: Findings from the Irish Longitudinal Study on Ageing

ObjectiveTo examine a novel measurement of autonomic innervation, the early heart rate response to orthostasis, in relation to sleep duration and disturbance (actigraphy-based and self-reported) in healthy older adults. DesignCross-sectional analyses of a nationally representative prospective cohort study, the Irish Longitudinal Study on Ageing (TILDA). ParticipantsNine hundred sixty community-dwelling adults aged 50 and over (mean age 65.6 ± 8.1; 53% women). MeasurementOrthostatic heart rate response was measured during an active stand test. Beat-to-beat heart rate was monitored over 3 minutes using noninvasive digital photoplethysmography. Mean values at each 10-second time point after standing were generated and differences from baseline at each time point were used for analysis. Actigraphy-based sleep measures were extracted from wrist-worn GENEactiv devices; self-reported sleep measures using interview questions. ResultsLinear mixed-effects regression analyses, with inclusion of a large number of confounders, show that self-reported sleep duration and actigraphy-based sleep duration and disturbance were associated with altered orthostatic heart rate response, particularly within the first 20 seconds poststanding. Self-reported short sleep (β = -0.06; 95% confidence interval [CI]: -0.11, -0.01) and long sleep (β = -0.15; 95% CI: -0.24, -0.05) and actigraphy-based short sleep (β = -0.08; 95% CI: -0.14, -0.01) were characterized by a smaller increase at 10 seconds (p < .01). Actigraphy-based short sleep (β = 0.15; 95% CI: 0.08, 0.22) and sleep disturbance (β = 0.04; 95% CI: 0.02, 0.06) were associated with a slower return toward baseline at 20 seconds (p < .001). ConclusionsOur findings suggest sympathetic dysregulation, impaired vagal reactivation, and/or decreased baroreceptor sensitivity in the presence of shortened or disturbed sleep.

Bidirectional Relations Between Daily Stress and Sleep Among Black Emerging Adults.

Black adults experience higher levels of stress and more dysfunctional sleep patterns compared to their White peers, both of which may contribute to racial disparities in chronic health conditions. Dysfunctional sleep patterns are also more likely in emerging adults compared to other age groups. Daily stress-sleep relations in Black emerging adults are understudied. This study used ecological momentary assessment (EMA) and wrist-worn actigraphy to examine bidirectional associations between daily stress and sleep among Black emerging adults. Black college freshmen (N = 50) completed an EMA protocol (i.e., five EMA prompts/day) and wore an accelerometer for 7 days. The first EMA prompt of each day assessed sleep duration and quality. All EMA prompts assessed stress. Wrist-worn actigraphy assessed nocturnal sleep duration, sleep onset latency, sleep efficiency, and waking after sleep onset. At the within-person level, stress experienced on a given day was not associated with any sleep metrics that night (p > .05). On evenings when actigraphy-based sleep duration was shorter (B = -0.02, p = .01) and self-reported sleep quality was poorer (B = -0.12, p = .02) than usual, stress was greater the following day. At the between-person level, negative bidirectional relations existed between stress and actigraphy-based waking after sleep onset (stress predicting sleep: B = -0.35, p = .02; sleep predicting stress: B = -0.27, p = .04). Among Black emerging adults, associations between daily sleep and stress vary at the between- and within-person level and are dependent upon the sleep metric assessed. Future research should compare these relations across different measures of stress and different racial/ethnic groups to better understand health disparities.

Early life socioeconomic differences in associations between childhood sleep and academic performance

Poor sleep can negatively impact children's academic performance. However, it is unknown whether early-life socioeconomic status (SES) moderates later sleep and academics. We tested associations between actigraphy-based sleep duration and midpoint time, and parent-reported sleep problems with objective and subjective measures of academic performance. We also examined whether relations varied by early and concurrent SES. Children (n = 707; 52% female; Mage = 8.44 years; 28.7% Hispanic/Latino; 29.7% at/below poverty line) were assessed at 12 months for SES and eight years for SES, sleep, and academics. There were no main effects of sleep on academics. More sleep problems predicted lower Applied Problems performance for low SES children (b = −0.73, p < .05) and better performance for high SES children (b = 0.69, p < .05). For high SES children, greater sleep problems (b = −0.11, p < .05) and longer sleep duration (b = −0.11, p < .05) predicted lower academic achievement. However, most associations were consistent across SES, illustrating the complex interplay between sleep, academic outcomes, and SES.

Associations of sleep duration and sleep-wake rhythm with lung parenchymal abnormalities on computed tomography: TheMESA study.

Impairment of the circadian rhythm promotes lung inflammation and fibrosis in pre-clinical models. We aimed to examine whether short and/or long sleep duration and other markers of sleep-wake patterns are associated with a greater burden of lung parenchymal abnormalities on computed tomography among adults. We cross-sectionally examined associations of sleep duration captured by actigraphy with interstitial lung abnormalities (n=1111) and high attenuation areas (n=1416) on computed tomography scan in the Multi-Ethnic Study of Atherosclerosis at Exam 5 (2010-2013). We adjusted for potential confounders in logistic and linear regression models for interstitial lung abnormalities and high attenuation area, respectively. High attenuation area models were also adjusted for study site, lung volume imaged, radiation dose and stratified by body mass index. Secondary exposures were self-reported sleep duration, sleep fragmentation index, sleep midpoint and chronotype. The mean age of those with longer sleep duration (≥ 8hr) was 70years and the prevalence of interstitial lung abnormalities was 14%. Increasing actigraphy-based sleep duration among participants with ≥ 8hr of sleep was associated with a higher adjusted odds of interstitial lung abnormalities (odds ratio of 2.66 per 1-hr increment, 95% confidence interval 1.42-4.99). Longer sleep duration and higher sleep fragmentation index were associated with greater high attenuation area on computed tomography among participants with a body mass index < 25kg m-2 (p-value for interaction < 0.02). Self-reported sleep duration, later sleep midpoint and evening chronotype were not associated with outcomes. Actigraphy-based longer sleep duration and sleep fragmentation were associated with a greater burden of lung abnormalities on computed tomography scan.

Perceived home sleep environment: associations of household-level factors and in-bed behaviors with actigraphy-based sleep duration and continuity in the Jackson Heart Sleep Study.

In an older African-American sample (n = 231) we tested associations of the household environment and in-bed behaviors with sleep duration, efficiency, and wakefulness after sleep onset (WASO). Older adult participants completed a household-level sleep environment questionnaire, a sleep questionnaire, and underwent 7-day wrist actigraphy for objective measures of sleep. Perceived household environment (self-reported) was evaluated using questions regarding safety, physical comfort, temperature, noise, and light disturbances. In-bed behaviors included watching television, listening to radio/music, use of computer/tablet/phone, playing video games, reading books, and eating. To estimate the combined effect of the components in each domain (perceived household environment and in-bed behaviors), we calculated and standardized a weighted score per sleep outcome (e.g. duration, efficiency, WASO), with a higher score indicating worse conditions. The weights were derived from the coefficients of each component estimated from linear regression models predicting each sleep outcome while adjusting for covariates. A standard deviation increase in an adverse household environment score was associated with lower self-reported sleep duration (β = -13.9 min, 95% confidence interval: -26.1, -1.7) and actigraphy-based sleep efficiency (β = -0.7%, -1.4, 0.0). A standard deviation increase in the in-bed behaviors score was associated with lower actigraphy-based sleep duration (β = -9.7 min, -18.0, -1.3), sleep efficiency (β = -1.2%, -1.9, -0.6), and higher WASO (5.3 min, 2.1, 8.6). Intervening on the sleep environment, including healthy sleep practices, may improve sleep duration and continuity among African-Americans.

176 Linear and Nonlinear Associations Between Sleep and Academic Achievement in Middle Childhood: The Role of Early Life SES

Abstract Introduction Elementary-aged children in low socioeconomic environments are more likely to experience poor sleep, which can negatively impact academic performance. However, it is unknown whether early-life socioeconomic status (SES) influences associations between sleep and academic achievement later in childhood. Using a demographically diverse sample of children followed longitudinally from 1 to 8 years, we tested linear and nonlinear associations between actigraphy-based sleep duration, midpoint time, sleep duration variability, and parent-reported sleep problems with academic achievement. In addition, we examined whether these associations varied by early SES. Methods The sample comprised 707 twins (52% female; Mage=8.44 years; 28.7% Hispanic/Latinx; 29.7% at or below the poverty line). SES was ascertained at 1 and 8 years, and children wore actigraph watches to assess sleep for 7 nights (Mnights=6.79) and completed the Applied Math, Picture Vocabulary, and Passage Comprehension subtests of the Woodcock-Johnson IV Tests of Achievement. Primary caregivers also reported on their children’s sleep and academic performance (Children’s Sleep Habits Questionnaire and Health and Behavior Questionnaire, respectively). Results Sleep was not linearly related to academic achievement, but there was a significant quadratic association between sleep midpoint with Picture Vocabulary (b=0.28, p&amp;lt;.01) and Passage Comprehension (b=0.17, p&amp;lt;.05). More parent-reported sleep problems were negatively related to Applied Problems performance for lower (b=-1.16, p&amp;lt;.001) and positively associated for higher early SES (b = 1.00, p &amp;lt; .01). More parent-reported sleep problems predicted lower Passage Comprehension for lower (b = -0.59, p &amp;lt; .05), but not higher early SES. Longer sleep duration predicted higher parent-reported academic achievement for lower early SES (b=0.14, p&amp;lt;.01) and lower achievement for higher early SES (b=-0.23, p&amp;lt;.001). Conclusion Our findings illustrate the complex, sometimes nonlinear associations between children’s sleep and academic performance. Many associations varied by early-life SES, suggesting that early childhood environments have long-lasting implications for child functioning, over and above the effect of concurrent SES. Increasing the quantity and quality of children’s sleep could improve academic outcomes, particularly for children who have experienced socioeconomic disadvantage. Support (if any) This research was supported by grants from NICHD (R01HD079520 and R01HD086085) and ASU T. Denny Sanford School of Social and Family Dynamics.

Discrepancies in self-reported and actigraphy-based sleep duration are associated with self-reported insomnia symptoms in community-dwelling older adults

ObjectivesTo establish agreement between self-reported and actigraphy-based total sleep time (TST). To determine the impact of self-reported sleep problems on these measurements. DesignCross-sectional study using data from Wave 3 of The Irish Longitudinal Study on Ageing (2014–2015). ParticipantsCommunity-dwelling older adults, aged ≥50 years, with self-reported sleep information and ≥4 days of actigraphy-based TST (n = 1520). MeasurementSelf-reported total sleep time, daytime sleepiness, insomnia symptoms (trouble falling asleep, trouble waking too early) measured during a structured self-interview. Actigraphy-based total TST was collected using GENEactiv wrist-worn accelerometers. Demographic characteristics and health information were controlled for. Analyses included descriptive statistics, reliability and agreement analysis using paired t-tests, intra-class correlations and Bland-Altman analysis. Linear regression was used to model associations with measurement discrepancies. ResultsParticipants reported that they slept 7.0 hours (SD: 1.4, Range: 2.0–13.0 hours) on average, compared to 7.7 hours (SD: 1.2 hours, Range: 3.0–13.0 hours) recorded by accelerometry. Trouble falling asleep or waking too early “most of the time” were associated with under-reporting of sleep by 2.3, and 2.2 hours respectively. Agreement between measurements had an intra-class correlation of 0.18 and wide 95% limits of agreement (-3.90 to 2.55 hours). Under-reporting of sleep was independently associated with insomnia symptoms. ConclusionThe agreement between self-reported and actigraphy-based TST in community dwelling older adults was low. Self-reported insomnia symptoms were independently associated with under-reporting of sleep. Studies seeking to measure sleep duration should consider inclusion of questions measuring experience of insomnia symptoms to account for potential influence on measurements.

1092 Attention-deficit/hyperactivity Disorder Symptoms And Sleep Characteristics Within A Seasonal Affective Disorder Spectrum

Abstract Introduction Seasonal affective disorder (SAD) increases risk for attention-deficit/hyperactivity disorder (ADHD), although the mechanism linking SAD and ADHD is unknown. Prior research has identified insomnia and delayed sleep phase in both ADHD and SAD. We hypothesized that sleep duration and timing in SAD would be associated with the severity of ADHD symptoms. Methods Adults with SAD (n = 45) and subsyndromal SAD (S-SAD; n = 18) aged 19-66 years from Pittsburgh, PA., were assessed for ADHD symptoms, self-report sleep quality, depression severity, and daytime sleepiness in the Winter. Participants wore an Actiwatch for 4-14 days, from which we calculated sleep-onset latency, total sleep time, sleep midpoint, and sleep efficiency. We conducted a hierarchical multivariate linear regression to determine if sleep characteristics predict ADHD symptom severity in our sample while controlling for depressive symptoms. Age and gender were added in Step 1, seasonal depression severity in Step 2, actigraphy-based total sleep time, sleep onset latency, midpoint, and efficiency in Step 3, and self-reported sleep quality and daytime sleepiness in Step 4. Results Participants mostly scored in the “likely” or “highly likely” ADHD range (87.30%, n=55), higher than the national prevalence rate (4.4%). When controlling for age, gender, and depression severity, only shorter actigraphy-based total sleep time was associated with higher ADHD symptom severity (β=-0.30, p&amp;lt;0.05). However, when self-reported sleep quality and daytime sleepiness were added as predictors, total sleep time was no longer a statistically-significant predictor of ADHD symptom severity and only daytime sleepiness predicted ADHD symptom severity (β=0.31, p&amp;lt;0.05). Conclusion Our results suggest that individuals with SAD who experience daytime sleepiness and/or possibly shorter actigraphy-based sleep duration experience higher ADHD symptom severity. Treatments like Trans-C or CBT-I to improve daytime sleepiness and sleep duration may be indicated for SAD patients who present with comorbid ADHD symptoms. Support NIMH K.A.R. MH103303

Prospective association between suicide cognitions and emotional responses to a laboratory stressor: The mediating role of nightly subjective sleep quality

BackgroundSleep is a reliable correlate of suicidal thoughts and behaviors (STBs), yet few studies have directly examined negative affect in the context of this association. The present study combined daily experience methods with a laboratory paradigm to investigate suicide cognitions as a predictor of emotional responses to environmental stressors, and tested the role of nightly sleep parameters. Method72 participants (Mage = 24.25; 41 with a recent history of suicide ideation and 31 without a history of STBs) completed a four-day study. Suicide cognitions were measured on the first day, and actigraphy-based sleep duration and fragmentation, and morning ratings of prior night subjective sleep quality (SSQ) were subsequently measured over three consecutive nights. Participants returned on the fourth day to complete the Trier Social Stress Task, where self-report changes in negative affect immediately post-task (i.e., reactivity) and five minutes post-task (i.e., recovery) were observed. ResultsRegression analyses indicated that suicide cognitions predicted negative affect reactivity and recovery. Simple mediation analyses revealed that SSQ partially mediated the relation between suicide cognitions and negative affect recovery (especially shame), but not reactivity. No significant associations were observed for the actigraphy-based sleep parameters. LimitationsJust three nights of actigraphy-based data collection. A single item was used to measure SSQ. ConclusionsSuicide cognitions predict negative affective responses to situational stressors and SSQ may have a key role in this effect, especially the duration of negative emotional reactions. Hence, sleep and emotional reactivity may be potential targets for suicide prevention efforts.

Erratum to: What does a good night's sleep mean? Nonlinear relations between sleep and children's cognitive functioning and mental health.

Study objectives We attempted to identify the duration and quality of sleep associated with the optimal child outcomes in key developmental domains including cognitive functioning, academic performance, and mental health. In doing so, we examined nonlinear associations between the sleep and developmental variables. Based on racial/ethnic disparities in children's sleep, we assessed this variable as a moderator of examined relations. Methods Two hundred eighty-two children participated (Mage = 9.4 years, SD = .72; 52% boys; 65% white/European American, 35% black/African American). Sleep was examined with actigraphy for seven consecutive nights and with self-reports. Actigraphy-based sleep duration (minutes) and quality (efficiency), as well as self-reported sleep quality were derived. Children reported on their mental health and were administered cognitive performance tests. Mothers and teachers reported on children's mental health; teachers also reported on academic functioning. Schools provided academic achievement data. Results Sleep duration had an accelerating nonlinear negative association with externalizing behaviors. Nonlinear associations were also detected between both actigraphy-derived and subjective reports of sleep quality and multiple developmental domains including academic functioning and mental health and the best functioning corresponded with the highest levels of sleep quality. Emphasizing the importance of individual differences, several examined associations were moderated by race/ethnicity. Conclusions Sleep duration and quality emerged as nonlinear predictors of multiple domains of child development. Findings illustrate that the benefits of longer and better-quality sleep did not taper off and that assessments of nonlinear relations may enhance understanding of the nature of associations between sleep and child functioning.

0216 The Sleep Environment: Associations between Household-level Factors and Actigraphy-based Sleep Duration and Disruption in the Jackson Heart Sleep Study (JHSS)

0216 The Sleep Environment: Associations between Household-level Factors and Actigraphy-based Sleep Duration and Disruption in the Jackson Heart Sleep Study (JHSS)

What does a good night's sleep mean? Nonlinear relations between sleep and children's cognitive functioning and mental health.

We attempted to identify the duration and quality of sleep associated with the optimal child outcomes in key developmental domains including cognitive functioning, academic performance, and mental health. In doing so, we examined nonlinear associations between the sleep and developmental variables. Based on racial/ethnic disparities in children's sleep, we assessed this variable as a moderator of examined relations. Two hundred eighty-two children participated (Mage = 9.4 years, SD = .72; 52% boys; 65% white/European American, 35% black/African American). Sleep was examined with actigraphy for seven consecutive nights and with self-reports. Actigraphy-based sleep duration (minutes) and quality (efficiency), as well as self-reported sleep quality were derived. Children reported on their mental health and were administered cognitive performance tests. Mothers and teachers reported on children's mental health; teachers also reported on academic functioning. Schools provided academic achievement data. Sleep duration had an accelerating nonlinear negative association with externalizing behaviors. Nonlinear associations were also detected between both actigraphy-derived and subjective reports of sleep quality and multiple developmental domains including academic functioning and mental health and the best functioning corresponded with the highest levels of sleep quality. Emphasizing the importance of individual differences, several examined associations were moderated by race/ethnicity. Sleep duration and quality emerged as nonlinear predictors of multiple domains of child development. Findings illustrate that the benefits of longer and better-quality sleep did not taper off and that assessments of nonlinear relations may enhance understanding of the nature of associations between sleep and child functioning.

Association between actigraphy-based sleep duration variability and cardiovascular risk factors – Results of a population-based study

BackgroundAlthough a few studies suggest an adverse effect of sleep duration variability on cardiovascular risk factor, others did not and this association remains controversial. Moreover, most studies were non-representative of the general population, used different sleep duration variability measures, and relied on self-reported sleep duration. We aimed to assess the association between different, actigraphy-based sleep duration variability measures and cardiovascular risk factors in a population-based sample. MethodsIn a middle-aged population-based cohort, 2598 subjects had data on sleep duration variability measured by actigraph over 14 days. Multivariable logistic regressions were performed to assess the relationship between different sleep duration variability measures [ie, night-to-night variability (NNV), range between shortest and longest sleep duration (RSL), range between average weekday and weekend sleep duration (RWW)] and cardiovascular risk factors including obesity, diabetes and hypertension. ResultsSubjects with highest sleep duration variability - measured as NNV, RSL and RWW, were more likely to be obese. These associations robust in most but not all sensitivity analyses, and no associations between sleep duration variability measures and diabetes or hypertension were found. ConclusionThere is a possible association between high sleep duration variability and obesity, although results were not robust in all sensitivity analyses. Further, no associations between sleep duration variability and other cardiovascular risk factor such as diabetes or hypertension were found.

Work-family conflict, cardiometabolic risk, and sleep duration in nursing employees.

We investigated associations of work-family conflict and work and family conditions with objectively measured cardiometabolic risk and sleep. Multilevel analyses assessed cross-sectional associations between employee and job characteristics and health in analyses of 1,524 employees in 30 extended-care facilities in a single company. We examined work and family conditions in relation to: (a) validated, cardiometabolic risk score based on measured blood pressure, cholesterol, glycosylated hemoglobin, body mass index, and self-reported tobacco consumption and (b) wrist actigraphy-based sleep duration. In fully adjusted multilevel models, work-to-family conflict but not family-to-work conflict was positively associated with cardiometabolic risk. Having a lower level occupation (nursing assistant vs. nurse) was associated with increased cardiometabolic risk, whereas being married and having younger children at home was protective. A significant Age × Work-to-Family Conflict interaction revealed that higher work-to-family conflict was more strongly associated with increased cardiometabolic risk in younger employees. High family-to-work conflict was significantly associated with shorter sleep duration. Working long hours and having children at home were both independently associated with shorter sleep duration. High work-to-family conflict was associated with longer sleep duration. These results indicate that different dimensions of work-family conflict may pose threats to cardiometabolic health and sleep duration for employees. This study contributes to the research on work-family conflict, suggesting that work-to-family and family-to-work conflict are associated with specific health outcomes. Translating theory and findings to preventive interventions entails recognition of the dimensionality of work and family dynamics and the need to target specific work and family conditions.

Relations between daytime pre‐ejection period reactivity and sleep in late childhood

The sympathetic nervous system and children's sleep serve critical arousal regulation functions. Shortened pre-ejection period, a reliable indirect index of greater sympathetic nervous system activity, has been associated with reduced sleep duration and quality in adults, but limited evidence exists in children regarding associations between pre-ejection period and sleep. We examined relations between pre-ejection period reactivity in response to a laboratory-based stressor and multiple parameters of actigraphy-based sleep duration and quality in children. The sample included 123 boys and 112 girls [mean age=11.31years, standard deviation (SD)=0.63years]. Controlling for body mass index, sex and pre-ejection period baseline, increased sympathetic nervous system reactivity, indexed by a lower level of pre-ejection period during the challenge than the baseline, was associated with worse sleep quality indicated by lower sleep efficiency, greater sleep activity and greater long wake episodes. The findings add to a small literature on relations between sympathetic nervous system functioning and children's sleep, suggesting that poor sleep quality is related to dysregulation of this stress response system.

Sleep and Antibody Response to Hepatitis B Vaccination

Experimental evidence links poor sleep with susceptibility to infectious illness; however, it remains to be determined if naturally occurring sleep is associated with immune responses known to play a role in protection against infection. The aim of this study was to determine whether sleep duration, sleep efficiency, and sleep quality, assessed in the natural environment, predict magnitude of antibody responses to a novel antigen among community volunteers in midlife. Observational. Healthy midlife adults (n = 125; 70 female; age 40-60 yr) received the standard 3-dose hepatitis B vaccination series. Actigraphy and electronic sleep diaries were used to assess sleep duration, sleep efficiency, and subjective sleep quality. Viral-specific antibody titers were obtained prior to the 2nd and 3rd vaccination to assess primary and secondary antibody responses. Clinical protection status (anti-hepatitis B surface antigen immunoglobulin G ≥ 10 mIU/ml) was assessed 6 mo after the final immunization. Regression analyses revealed that shorter actigraphy-based sleep duration was associated with a lower secondary antibody response independent of age, sex, body mass index, and response to the initial immunization. Shorter sleep duration, measured by actigraphy and sleep diary, also predicted a decreased likelihood of being clinically protected from hepatitis B at the conclusion of the vaccination series. Neither sleep efficiency nor subjective sleep quality were significant predictors of antibody response. Short sleep duration in the natural environment may negatively affect in vivo antibody responses to novel antigens, providing a possible explanation for observed associations of poor sleep with increased susceptibility to infectious disease.