Recovery Sleep After Sleep Restriction Is Insufficient to Return Elevated Daytime Heart Rate and Systolic Blood Pressure to Baseline Levels.

OBJECTIVE: Sleep restriction alters daytime cardiac activity, including elevating heart rate (HR) and blood pressure (BP). There is minimal research on the cumulative effects of sleep loss and the response after subsequent recovery sleep on HR and BP. This study examined patterns of HR and BP across baseline, sleep restriction, and recovery conditions using multiple daytime cardiac measurements. METHODS: Participants (15 healthy men, mean [standard deviation] = 22.3 [2.8] years) completed an 11-day inpatient protocol with three nights of 10 hours/night baseline sleep opportunity, five sleep restriction nights (5-hour/night sleep opportunity), and two recovery nights (10-hour/night sleep opportunity). Resting HR and BP were measured every 2 hours during wake. Multilevel models with random effects for individuals examined daytime HR and BP across study conditions and days into the study. RESULTS: Mean daytime HR was 1.2 (0.5) beats/min lower during sleep restriction compared with baseline ( p < .001). During recovery, HR was 5.5 (1.0) beats/min higher ( p < .001), and systolic BP (SBP) was 2.9 (1.1) mm Hg higher ( p = .009). When accounting for days into the study (irrespective of condition) and measurement timing across the day, HR increased by 7.6 beats/min and SBP increased by 3.4 mm Hg across the study period ( p < .001). CONCLUSIONS: Our findings suggest that daytime HR and SBP increase after successive nights of sleep restriction, even after accounting for measurement time of day. HR and SBP did not recover to baseline levels after two recovery nights of sleep, suggesting that longer recovery sleep may be necessary to recover from multiple, consecutive nights of moderate sleep restriction.

Why so slangry (sleepy and angry)? Shorter sleep duration and lower sleep efficiency predict worse next-day mood in adolescents.

PURPOSE: The goal of this study was to evaluate the relationships of actigraphic nighttime sleep duration and quality with next-day mood among urban adolescents using a micro-longitudinal design. METHODS: A subsample (N = 525) of participants from the Fragile Families & Child Wellbeing Study (mean age: 15.4 years; 53% female; 42% Black non-Hispanic, 24% Hispanic/Latino, 19% White non-Hispanic) in the United States between 2014 and 2016 concurrently wore a wrist actigraphic sleep monitor and rated their daily mood in electronic diaries for about 1 week. Multilevel models tested the within-person temporal associations of nightly sleep duration and sleep maintenance efficiency with next-day reports of happiness, anger, and loneliness. The models also tested the between-person associations of sleep variables and mood. Models adjusted for sociodemographic and household characteristics, weekend, and school year. RESULTS: After nights when adolescents obtained longer sleep duration than their usual, they reported lower ratings of anger (B = -.03, p < .01) the next day. After nights when adolescents had higher sleep maintenance efficiency than their usual, they reported higher ratings of happiness (B = .02, p < .01) the next day. Adolescents who had longer average sleep duration reported lower ratings of anger (B = -.08, p < .01) and loneliness (B = -.08, p < .01) compared to others. There was no within-person association of sleep duration or efficiency with loneliness. Sleep duration was not associated with happiness between adolescents, and sleep maintenance efficiency was not associated with any mood measure between adolescents. CONCLUSIONS: Improvements to nightly sleep may help increase happiness and decrease anger the following day in adolescents. Promoting sleep health is recommended to improve mood.

Worse sleep health predicts less frequent breakfast consumption among adolescents in a micro-longitudinal analysis.

BACKGROUND: Poor self-reported sleep health has been linked to not consuming breakfast in adolescents, but it is unknown whether poor sleep measured objectively predicts next-day breakfast consumption within adolescents. We investigated within- and between-person associations of objectively measured sleep dimensions and subjective sleep quality with adolescent breakfast consumption. METHODS: Data were collected from a micro-longitudinal substudy of the Year 15 wave of the Fragile Families and Child Wellbeing Study (n = 590). Adolescents wore an actigraphy device and completed daily diaries for ~ 1 week (M ± SD = 5.6 ± 1.4 nights per adolescent, range: 3-9), where they rated their sleep quality and reported whether they had eaten breakfast that day, with no specific definition of breakfast provided (M ± SD = 5.5 ± 1.4 days per adolescent, range: 3-9). Separate mixed models assessed whether actigraphy-measured sleep duration (linear and quadratic, sleep duration x sleep duration), timing, maintenance efficiency, and subjective quality predicted odds of breakfast consumption both within and between adolescents. Variability of sleep duration and timing (standard deviation per person), sleep regularity index (SRI), and social jetlag were tested as additional between-person predictors. Analyses with predictors other than sleep duration were adjusted for sleep duration. RESULTS: Following nights when adolescents had shorter or longer sleep duration (p = .005; curvilinear association), later sleep onset, or later sleep midpoint (both p = .025) than their own usual, they had lower odds of consuming breakfast the next day (within-person associations). Adolescents who on average had later sleep onset (p = .013) or midpoint (p = .013) or who reported lower sleep quality (p = .011) had lower average odds of consuming breakfast (between-person associations). Adolescents with greater variability of sleep duration (p = .005), midpoint (p = .004), or offset (p < .001) had lower average odds of consuming breakfast (between-person associations). Sleep maintenance efficiency (within or between adolescents), SRI, and social jetlag were not associated with breakfast consumption (all p > .10). CONCLUSIONS: Multiple dimensions of sleep health are associated with breakfast consumption, both within and between adolescents. Poor sleep and dietary behaviors in adolescence may negatively impact future metabolic health.

Various Types of Perceived Job Discrimination and Sleep Health Among Working Women: Findings From the Sister Study.

Job discrimination, a social stressor, may lead to sleep health disparities among workers; yet, limited research has examined this relationship and specific sources of job discrimination. We used a US sample of working women (n = 26,085), participants in the Sister Study (2008-2016), to examine the associations of perceived job discrimination due to sex, race, age, health conditions, and/or sexual orientation with sleep health. Cross-sectionally, linear or logistic regression models revealed that each source of job discrimination was independently associated with different sleep problems after controlling for other sources of job discrimination. Longitudinally, among participants without short sleep (<7 hours/night) at time 1 (2012-2014), age-specific job discrimination was associated with 21% increased odds of new-onset short sleep (odds ratio = 1.21, 95% confidence interval: 1.03, 1.43) at time 2 (2014-2016). Among those without insomnia symptoms at time 1, race-specific job discrimination was associated with 37% increased odds of new-onset insomnia symptoms (odds ratio = 1.37, 95% confidence interval: 1.07, 1.75) at time 2. Sex- and health-specific job discrimination also predicted new-onset sleepiness. There were dose-response relationships such that a greater number of sources of job discrimination (≥3) was associated with greater odds of prevalent and incident sleep problems. Perceived job discrimination may contribute to working women's poor sleep health over time, raising concerns about sleep health disparities emanating from the workplace.

Social jetlag, eating behaviours and BMI among adolescents in the USA.

There is a lack of research on associations of social jetlag with eating behaviours and obesity among adolescents. We examined the associations of social jetlag with eating behaviours and BMI in adolescents before and after adjustment for potential confounders. Self-report data were collected from 3060 adolescents (48·1 % female, mean age 15·59 (sd 0·77) years) from the Fragile Families and Child Wellbeing Study. In regression models, social jetlag predicted odds of consumption of breakfast, fruits/vegetables, fast food and sweetened drinks and BMI percentile. Primary models adjusted for school night sleep duration, sex, age, household income and youth living arrangements; secondary models further adjusted for race/ethnicity. In fully adjusted models, greater social jetlag was associated with lower odds of consumption of breakfast (OR = 0·92, P = 0·003) and fruits/vegetables (OR = 0·92, P = 0·009) and higher odds of consumption of fast food (OR = 1·18, P < 0·001) and sweetened drinks (OR = 1·18, P < 0·001). Social jetlag was positively associated with BMI percentile after additional adjustment for eating behaviours (b = 0·84, P = 0·037), but this relationship was attenuated after adjustment for race/ethnicity (b = 0·72, P = 0·072). Ethnoracial differences in social jetlag may attenuate the association of social jetlag with BMI and should be considered in future studies of circadian misalignment, eating behaviours and obesity markers.

Four nights of sleep restriction suppress the postprandial lipemic response and decrease satiety.

Chronic sleep restriction, or inadequate sleep, is associated with increased risk of cardiometabolic disease. Laboratory studies demonstrate that sleep restriction causes impaired whole-body insulin sensitivity and glucose disposal. Evidence suggests that inadequate sleep also impairs adipose tissue insulin sensitivity and the NEFA rebound during intravenous glucose tolerance tests, yet no studies have examined the effects of sleep restriction on high-fat meal lipemia. We assessed the effect of 5 h time in bed (TIB) per night for four consecutive nights on postprandial lipemia following a standardized high-fat dinner (HFD). Furthermore, we assessed whether one night of recovery sleep (10 h TIB) was sufficient to restore postprandial metabolism to baseline. We found that postprandial triglyceride (TG) area under the curve was suppressed by sleep restriction (P = 0.01), but returned to baseline values following one night of recovery. Sleep restriction decreased NEFAs throughout the HFD (P = 0.02) and NEFAs remained suppressed in the recovery condition (P = 0.04). Sleep restriction also decreased participant-reported fullness or satiety (P = 0.03), and decreased postprandial interleukin-6 (P < 0.01). Our findings indicate that four nights of 5 h TIB per night impair postprandial lipemia and that one night of recovery sleep may be adequate for recovery of TG metabolism, but not for markers of adipocyte function.

Two nights of recovery sleep restores the dynamic lipemic response, but not the reduction of insulin sensitivity, induced by five nights of sleep restriction.

Chronic inadequate sleep is associated with increased risk of cardiometabolic diseases. The mechanisms involved are poorly understood but involve changes in insulin sensitivity, including within adipose tissue. The aim of this study was to assess the effects of sleep restriction on nonesterified fatty acid (NEFA) suppression profiles in response to an intravenous glucose tolerance test (IVGTT) and to assess whether 2 nights of recovery sleep (a "weekend") is sufficient to restore metabolic health. We hypothesized that sleep restriction impairs both glucose and lipid metabolism, specifically adipocyte insulin sensitivity, and the dynamic lipemic response of adipocyte NEFA release during an IVGTT. Fifteen healthy men completed an inpatient study of 3 baseline nights (10 h of time in bed/night), followed by 5 nights of 5 h of time in bed/night and 2 recovery nights (10 h of time in bed/night). IVGTTs were performed on the final day of each condition. Reductions in insulin sensitivity without a compensatory change in acute insulin response to glucose were consistent with prior studies (insulin sensitivity P = 0.002; acute insulin response to glucose P = 0.23). The disposition index was suppressed by sleep restriction and did not recover after recovery sleep (P < 0.0001 and P = 0.01, respectively). Fasting NEFAs were not different from baseline in either the restriction or recovery conditions. NEFA rebound was significantly suppressed by sleep restriction (P = 0.01) but returned to baseline values after recovery sleep. Our study indicates that sleep restriction impacts NEFA metabolism and demonstrates that 2 nights of recovery sleep may not be adequate to restore glycemic health.

D-dimer levels in VTE patients with distal and proximal clots.

OBJECTIVES: There is growing evidence that venous thromboembolism (VTE) patients with distal clots (distal calf deep vein thrombosis [DVT] and sub-segmental pulmonary embolism [PE]) may not routinely benefit from anticoagulation. We compared the D-dimer levels in VTE patients with distal and proximal clots. METHODS: We conducted a multinational, prospective observational study of low-to-intermediate risk adult patients presenting to the emergency department (ED) with suspected VTE. Patients were classified as distal (calf DVT or sub-segmental PE) or proximal (proximal DVT or non-sub-segmental PE) clot groups and compared with univariate and multivariate analyses. RESULTS: Of 1752 patients with suspected DVT, 1561 (89.1%) had no DVT, 78 (4.4%) had a distal calf DVT, and 113 (6.4%) had a proximal DVT. DVT patients with proximal clots had higher D-dimer levels (3760 vs. 1670 mg/dL) than with distal clots. Sensitivity and negative predictive value (NPV) for proximal DVT at an optimal D-dimer cutoff of 5770 mg/dL were 40.7% and 52.1% respectively. Of 1834 patients with suspected PE, 1726 (94.1%) had no PE, 7 (0.4%) had isolated sub-segmental PE, and 101 (5.5%) had non-sub-segmental PE. PE patients with proximal clots had higher D-dimer levels (4170 vs. 2520 mg/dL) than those with distal clots. Sensitivity and NPV for proximal PE at an optimal D-dimer cutoff of 3499 mg/dL were 57.4% and 10.4% respectively. CONCLUSIONS: VTE patients with proximal clots had higher D-dimer levels than patients with distal clots. However, D-dimer levels cannot be used alone to discriminate between VTE patients with distal or proximal clots.

Functional decoupling of melatonin suppression and circadian phase resetting in humans.

KEY POINTS: There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the association between melatonin suppression and phase resetting in humans. Sixteen young healthy participants received nocturnal bright light (∼9500 lux) exposure of continuous or intermittent patterns, and different durations ranging from 12 min to 6.5 h. Intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every bright light stimulus in an intermittent exposure pattern induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest that phase shifts and melatonin suppression are functionally independent such that one cannot be used as a proxy measure of the other. ABSTRACT: Continuous experimental light exposures show that, in general, the conditions that produce greater melatonin suppression also produce greater phase shift, leading to the assumption that one can be used as a proxy for the other. We tested this association in 16 healthy individuals who participated in a 9-day inpatient protocol by assessing melatonin suppression and phase resetting in response to a nocturnal light exposure (LE) of different patterns: (i) dim-light control (<3 lux; n = 6) or (ii) two 12-min intermittent bright light pulses (IBL) separated by 36 min of darkness (∼9500 lux; n = 10). We compared these results with historical data from additional LE patterns: (i) dim-light control (<3 lux; n = 11); (ii) single continuous bright light exposure of 12 min (n = 9), 1.0 h (n = 10) or 6.5 h (n = 6); or (iii) an IBL light pattern consisting of six 15-min pulses with 1.0 h dim-light recovery intervals between them during a total of 6.5 h (n = 7). All light exposure groups had significantly greater phase-delay shifts than the dim-light control condition (P < 0.0001). While a monotonic association between melatonin suppression and circadian phase shift was observed, intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every IBL stimulus induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest unique specificities in how light-induced phase shifts and melatonin suppression are mediated such that one cannot be used as a proxy measure of the other.

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.

In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength-enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety.

Study protocol: a randomised controlled trial of a nurse-led community-based self-management programme for improving recovery among community-residing stroke survivors.

BACKGROUND: Recovery after stroke is long-term and demanding. Optimising community-residing stroke survivors' capability to self-manage their health is integral. Recent systematic reviews have shown that stroke self-management programmes were associated with significant improvement in stroke survivors' health-related quality of life and self-efficacy. However some programmes were not designed with an underpinning theoretical framework. The aim of this study is to compare the effectiveness of a nurse-led stroke self-management programme with usual care on recovery of community-residing stroke survivors. METHODS/DESIGN: A single-blinded, two-arm, randomised controlled trial will be conducted. Patients with a history of first or recurrent ischaemic or haemorrhagic stroke who will be discharged to home settings will be recruited from acute stroke units of three acute public hospitals in Hong Kong. The estimated sample size is 160 (80 participants per group). Eligible participants will be randomised to receive either usual care or a 4-week nurse-led community-based self-management programme plus usual care after discharge. The programme, underpinned by Bandura's constructs of self-efficacy and outcome expectation, includes one individual home visit, two community-based group sessions, and three follow-up phone calls. Primary outcomes include stroke survivors' self-efficacy and outcome expectation of performing self-management behaviours. Secondary outcomes include health-related quality of life, satisfaction with performance of self-management behaviours, depressive symptoms, and community reintegration. Participants will be assessed at baseline and at 8 weeks after randomisation. Generalised estimating equations will be performed to evaluate the significance of changes in outcomes over time by treatment condition. Research ethics approvals were obtained. DISCUSSION: It is expected that stroke survivors receiving the stroke self-management programme will have improved self-efficacy, outcome expectation, and performance of stroke self-management behaviours. Enhanced quality of life and level of community reintegration, and decreased depressive symptoms are also expected. The study results will provide valuable evidence to inform future identification and evaluation of best approach to deliver stroke self-management programmes to enhance community-residing stroke survivors' recovery. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02112955 ; date of registration: 09/04/2014.

Translation and Validation of a Chinese Version of the Stroke Self-Efficacy Questionnaire in Community-Dwelling Stroke Survivors.

BACKGROUND: Self-efficacy is a significant factor influencing stroke survivors' participation in self-care and outcomes. The Stroke Self-Efficacy Questionnaire (SSEQ) is a stroke-specific measure of stroke survivors' self-efficacy in performing daily functional activities and self-management. However, there has been no Chinese version of the questionnaire. OBJECTIVE: The current study aims to examine the reliability and validity of a translated Chinese version of SSEQ (SSEQ-C). METHODS: The English version of SSEQ has been translated into Chinese. A descriptive study was conducted. A convenience sample of 135 Chinese stroke survivors (mean age 58.9, SD 9.75) was recruited from three community centers and a stroke support group. Eligible participants completed the SSEQ-C, and the Chinese versions of General Self-Efficacy Scale (GSES), Frenchay Activities Index (FAI), and Stroke-Specific Quality of Life Scale (SSQOL). Thirty of the participants completed the questionnaires at baseline and 4 weeks afterwards. RESULTS: SSEQ-C had a high internal consistency (Cronbach's α 0.92). Test-retest reliability was satisfactory with the intraclass correlation coefficient of the total scale 0.52. Positive correlations were found between the total scores of SSEQ-C, GSES, FAI, and SSQOL (Spearman's ρ: 0.48-0.68, p < 0.01), suggesting acceptable convergent validity. Principal component analysis suggested a two-factor model, namely "Live with new challenges" and "Activity and exercise engagement" in contrast to the single-factor model for the original questionnaire. CONCLUSION: The results suggest SSEQ-C is a reliable and valid tool for measuring Chinese community-dwelling stroke survivors' self-efficacy in managing post-stroke condition. More studies are warranted to confirm the two-factor model of the questionnaire.

Sex difference in the near-24-hour intrinsic period of the human circadian timing system.

The circadian rhythms of melatonin and body temperature are set to an earlier hour in women than in men, even when the women and men maintain nearly identical and consistent bedtimes and wake times. Moreover, women tend to wake up earlier than men and exhibit a greater preference for morning activities than men. Although the neurobiological mechanism underlying this sex difference in circadian alignment is unknown, multiple studies in nonhuman animals have demonstrated a sex difference in circadian period that could account for such a difference in circadian alignment between women and men. Whether a sex difference in intrinsic circadian period in humans underlies the difference in circadian alignment between men and women is unknown. We analyzed precise estimates of intrinsic circadian period collected from 157 individuals (52 women, 105 men; aged 18-74 y) studied in a month-long inpatient protocol designed to minimize confounding influences on circadian period estimation. Overall, the average intrinsic period of the melatonin and temperature rhythms in this population was very close to 24 h [24.15 ± 0.2 h (24 h 9 min ± 12 min)]. We further found that the intrinsic circadian period was significantly shorter in women [24.09 ± 0.2 h (24 h 5 min ± 12 min)] than in men [24.19 ± 0.2 h (24 h 11 min ± 12 min); P < 0.01] and that a significantly greater proportion of women have intrinsic circadian periods shorter than 24.0 h (35% vs. 14%; P < 0.01). The shorter average intrinsic circadian period observed in women may have implications for understanding sex differences in habitual sleep duration and insomnia prevalence.

Sleep-independent circadian rhythm of aldosterone secretion in healthy young adults.

OBJECTIVE: A diurnal variation in urine output has been described in humans, whereby it is lowest at night. Fluid balance hormones such as vasopressin and aldosterone as well as urine output have a diurnal variation. Although the diurnal variation of vasopressin results in part from a circadian rhythm, the variation in aldosterone has until recently been reported to be due to the sleep/wake cycle. The present study used a specialized protocol to explore whether aldosterone has an underlying circadian rhythm. METHODS: Ten healthy participants (average age 23.1) were enrolled in the 57.3-hour protocol that included an 8-hour baseline sleep episode, 40 hours in constant routine conditions (wakefulness, food and fluid intake, posture, and dim light), and a 9.3-hour recovery sleep. Blood samples for aldosterone were taken every 4 hours. Cosinor analysis was performed on the constant routine data to test the effect of the sleep/wake cycle on overall aldosterone secretion. RESULTS: There was a significant circadian rhythm during the 40-hour constant routine, independent of sleep, with aldosterone higher at the end of the biological night and lower at the end of the biological day. When analyzing data from the entire 57.3-hour protocol and controlling for this circadian rhythm, aldosterone concentration was significantly higher during the recovery night following the 40-hour sleep deprivation compared to the night spent awake. CONCLUSION: We found a significant endogenous circadian rhythm in the secretion of aldosterone, independent of sleep. In addition, as shown previously, there was a significant effect of the sleep/wake cycle on aldosterone secretion.

Effects of a 1-hour per night week-long sleep extension in college students on cardiometabolic parameters, hydration status, and physical activity: A pilot study.

OBJECTIVES: Short sleep duration is associated with poor physical health in college students. Few studies examine the effects of sleep extension on physical health in this population, who are susceptible to sleep loss. We examined health effects of a 1-week, 1-hour nightly sleep extension in college students. METHODS: Twelve healthy undergraduate college students (83% female; age 20.2 ± 1.5years) completed a study consisting of sleeping typically for 1week ("Habitual"), then extending sleep by ≥1 hour/night during the second week ("Extension"). Sleep and physical activity actigraphy were collected throughout. Following each week, participants completed cardiometabolic assessments including a meal response and provided a urine sample for markers of hydration. RESULTS: In Extension compared to Habitual, average sleep duration increased (mean change±SEM, +42.6 ± 15.1 minutes; p = .005), while subjective sleepiness (-1.8 ± 0.8 units; p = .040), systolic blood pressure (-6.6 ± 2.8 mmHg; p = .037), postprandial glucose area under the curve (-26.5 ± 10.2 mg/dL × h; p = .025) and time to baseline (-83.0 ± 46.4 minutes; p = .031) after the meal response, sedentary time (-44.3 ± 15.7 minutes; p = .018), and percentage of wake in moderate-to-vigorous activity (-0.89% ± 0.35%; p = .030) decreased. Participants who increased average sleep duration by ≥20 minutes (n = 9) were better hydrated according to urine osmolality (-187.0 ± 68.4 mOsm/kg; p = .026) and specific gravity (-0.01 ± 0.002 g/mL; p = .012) and had reduced odds of dehydration according to urine osmolality (≥800 mOsm/kg; -67%; OR=0.03; p = .035). CONCLUSIONS: This pilot study's findings suggest that sleep extension may improve cardiometabolic functioning and hydration, and alter sedentary behavior and physical activity, in college students. Sleep extension may be employed to improve multiple aspects of health in this sleep-deprived population.

Actigraphic sleep dimensions and associations with academic functioning among adolescents.

STUDY OBJECTIVES: There is mixed evidence regarding associations of sleep duration with academic functioning in adolescents and a lack of research on other sleep dimensions, particularly using objective sleep measures. We examined associations of multiple actigraphic sleep dimensions with academic functioning among adolescents. METHODS: Data were from the sleep sub-study of the age 15 wave of the Future of Families and Child Wellbeing Study (n = 774-782; 52% female), a national, diverse sample of teens. Adolescents wore wrist-actigraphs for ~1 week and completed a survey reporting academic performance and school-related behavioral problems. Regression models assessed whether average sleep duration, timing, maintenance efficiency, and SD-variability were associated with self-reported academic functioning in cross-sectional analyses adjusted for demographic characteristics, depressive symptoms, and anxious symptoms. RESULTS: Later sleep timing (hours) and greater sleep variability (SD-hours) were associated with poorer academic outcomes, including sleep onset variability with higher odds of receiving a D or lower (OR = 1.29), sleep onset (ß = -.07), sleep offset (ß = -.08), and sleep duration variability (ß = -.08) with fewer A grades, sleep offset with lower GPA (ß = -.07), sleep offset (OR = 1.11), sleep duration variability (OR = 1.31), and sleep onset variability (OR = 1.42) with higher odds of being suspended or expelled in the past 2 years, and sleep duration variability with greater trouble at school (ß = .13). Sleep duration, sleep maintenance efficiency, and sleep regularity index were not associated with academic functioning. CONCLUSIONS: Later sleep timing and greater sleep variability are risk factors for certain academic problems among adolescents. Promoting sufficient, regular sleep timing across the week may improve adolescent academic functioning.

Entrainment to gradual vs. immediate 8-hour phase advance shifts with and without short-wavelength enriched polychromatic green light.

OBJECTIVES: For optimal health and well-being the sleep episode and the circadian timing system should be properly aligned. We evaluated the effectiveness of different dynamic light and sleep/wake shift schedules for rapid circadian entrainment following an 8-hour advance of sleep. METHODS: Forty-three healthy participants completed an 8-day inpatient protocol in which the 8-hour sleep episode was advanced by 8 hours. Participants were assigned to one of five conditions: (1) dim ambient WHITE light and GRADUAL shift in which the sleep episode was incrementally advanced over 5days; (2) dim GREEN, short-wavelength (∼504 nm) polychromatic light and GRADUAL shift; (3) dim WHITE light and SLAM shift, including an abrupt 8-hour advance on day 3 following an extended 32-hour wake episode; (4) GREEN light and SLAM shift; or (5) COMBINED (higher illuminance WHITE plus GREEN) light and modified SLAM shift with 2 short naps scheduled on the day prior to the abrupt advance. Phase shifts of the plasma dim light melatonin onset and sleep measures were compared to examine effects of protocol condition. RESULTS: After 5days, the COMBINED light/modified SLAM shift condition showed larger phase advances of dim light melatonin onset (4.02 ± 1.13 hours) compared to the other 4 conditions (range 1.50 ± 0.96-2.83 ± 2.23 hours; p < .05) and resulted in increased REM sleep duration and fewer sleep disruptions. CONCLUSIONS: Consideration of the type of shift and the illuminance and wavelength of light may assist in designing lighting countermeasures to sleep and circadian disruption, which has implications for jetlag, shiftwork, and circadian rhythm sleep disorders.

Design and methods of the mobile assessment of cognition, environment, and sleep (MACES) feasibility study in newly diagnosed breast cancer patients.

Endocrine therapy (ET) for breast cancer treatment is associated with cognitive complaints, but their etiology is poorly understood. To address this, we developed and implemented an ambulatory assessment protocol consisting of wearable activity monitors, brief surveys of affect, context, and perceived impairments, and ultra-brief performance-based measures of cognition. Newly diagnosed, ER/PR+, stage 0-III, female breast cancer patients, were recruited. Ambulatory assessments were conducted on smart phones and wearable activity monitors were used to monitor sleep and physical activity. Participants were asked to complete five 7-day measurement bursts (one before starting ET and one each month for 4 consecutive months while on ET). We observed a consent rate of 36%, 27 women completed the study. Of the women that withdrew, 91% dropped prior to the midpoint of follow up. There were no significant differences in demographics, clinical breast cancer characteristics, sleep or physical activity patterns, or measures of cognition between women who completed versus withdrew. Women who did not complete the study provided fewer valid days of baseline data. In conclusion, while some women may be overwhelmed with their cancer diagnosis, we did not identify any predictive characteristics of women whom did not complete the study. This novel method enables the prospective study of psychological changes associated with cancer treatment, capturing a wide array of information about behavior, experience, and cognition, thus providing a picture of the lived experiences of cancer patients before and during exposure to ET.

Childhood sleep is prospectively associated with adolescent alcohol and marijuana use.

INTRODUCTION: Prior studies have examined the cross-sectional relationship between adolescent sleep and substance use; however, fewer have explored the long-term connections between childhood sleep and adolescent substance use. METHODS: This study investigated both cross-sectional associations during adolescence and prospective associations between childhood weeknight sleep and later alcohol and marijuana use in the Future of Families and Child Wellbeing Study, a diverse national birth cohort of urban children from 20 cities with populations greater than 200,000. Parents reported their child's bedtime at ages 3, 5, and 9 and their child's sleep duration at ages 5 and 9. RESULTS: At age 15, adolescents self-reported their bedtime, sleep duration, and alcohol and marijuana use (n=1,514). Logistic regression analyses for each substance use outcome at age 15 were adjusted for sex, age at time of assessment, race/ethnicity, income-relative-to-poverty threshold, family structure, and caregiver education level. At age 15, later bedtime (AOR=1.39; 95% CI=1.22, 1.57) and shorter sleep duration (AOR=1.28; 95% CI=1.14, 1.43) were associated with greater odds of consuming a full drink of alcohol more than once, and later bedtime was associated with greater odds of trying marijuana (AOR=1.35; 95% CI=1.20, 1.51). Unexpectedly, later bedtimes at age 3 were associated with lower odds of drinking alcohol by age 15 (AOR=0.74; 95% CI=0.59, 0.92). In contrast, later bedtimes at age 9 were associated with greater odds of drinking alcohol (AOR=1.45; 95% CI=1.11, 1.90). Additionally, later bedtime at age 5 (AOR=1.26; 95% CI=1.01, 1.58) and shorter sleep duration at age 9 (AOR=1.19; 95% CI=1.04, 1.36) were associated with greater odds of trying marijuana. CONCLUSION: Taken together, these associations support the importance of protecting childhood sleep habits to reduce the likelihood of substance use starting as early as mid-adolescence. IMPLICATIONS AND CONTRIBUTION: In this longitudinal cohort study, adolescents were more likely to have consumed alcohol or tried marijuana by age 15 if they had later bedtimes and shorter sleep duration during childhood and adolescence. Protecting sleep health throughout childhood may reduce the likelihood of substance use during early adolescence.

Interactive Screen-Based Activities Predict Worse Actigraphic Sleep Health That Night Among Adolescents.

PURPOSE: To determine the micro-longitudinal effects of duration and timing of screen-based activities on sleep within and between adolescents. METHODS: Daily survey and actigraphy data from the age 15 wave of the Future of Families and Child Wellbeing Study were analyzed using multilevel modeling. Four hundred seventy five adolescents provided three or more days of valid daily survey and nighttime sleep data. RESULTS: Within-person results showed that on days when adolescents played video games more than their daytime average ± SE (1.3 ± 1.2 hours), sleep onset (6 ± 2 minutes, p < .01) and midpoint (4 ± 2 minutes, p < .02) were delayed for each additional hour of gaming. Between-person results showed that for each hour adolescents used screens to communicate with friends across the day, sleep onset was later (11 ± 3 minutes, p < .01), sleep midpoint was later (8 ± 3 minutes, p < .01), and sleep duration was shorter (-5 ± 2 minutes, p < .03). Adolescents who used screens to communicate with friends or play video games in the hour before bed had later sleep onset (30 ± 14 minutes, p < .03) and midpoint (25 ± 13 minutes, p < .05). DISCUSSION: Among adolescents, passive screen usage such as browsing the Internet or watching videos may not affect sleep timing or duration, but limiting interactive screen-based activities could protect adolescent sleep health and well-being.