Late Sleep Timing Research Articles

Association between sleep timing and meal and snack patterns in schoolchildren in southern Brazil.

This study aimed to identify meal and snack patterns and assess their association with sleep timing in schoolchildren. This is a cross-sectional study carried out in 2018/2019 with 1333 schoolchildren aged 7-14 years from public and private schools in Florianópolis, Brazil. Previous-day dietary intake data for breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner, and evening snack were collected using a validated online questionnaire. Sleep timing was measured by the midpoint of sleep and classified as quartiles (very early, early, late and very late). Latent Class Analysis was performed to identify meal and snack patterns, and multinomial logistic regression was used to assess associations. Students with very late sleep timing were less likely to consume the "Coffee with milk, bread and cheese" breakfast pattern compared with very early group (35.4%, 95%CI 27.2-43.6 vs. 56.0%, 95%CI 48.5-63.4). Also, the former were more likely to consume the "Mixed" breakfast pattern (healthy and unhealthy foods) compared with very early students (40.0%, 95%CI 32.4- 46.7 vs. 28.0%, 95%CI 23.8- 32.0). The latter were more likely to eat the "Brazilian traditional, processed meat, egg and fish" lunch pattern to the late students (35.4%, 95%CI 30.3- 40.5 vs. 21.5%, 95%CI 15.2- 27.8) and less likely to consume the "Pasta and cheese" lunch pattern compared to the students with later sleep timing (10.1%, 95%CI 8.4- 11.9 vs. 17.1%, 95%CI 13.0- 21.1). Students with later sleep timing were more likely to eat ultra-processed food at mid-afternoon snacks compared with early group (56.3%, 95%CI 52.4- 60.2 vs. 47.2%, 95%CI 43.5- 50.8). The study findings suggest that morning preference appears to promote healthier breakfast, lunch, and afternoon snack patterns, whereas later sleep timing may pose challenges in maintaining healthy patterns at these meals/snacks.

Sleep timing and the prevalence of hypertension in middle-aged and older populations: the sleep heart health study

ObjectivesSleep characteristics such as duration, continuity, and irregularity are associated with the risk of hypertension. This study aimed to investigate the association between sleep timing (including bedtime, wake-up time, and sleep midpoint) and the prevalence of hypertension.MethodsParticipants were selected from the Sleep Heart Health Study (n = 5504). Bedtime and wake-up times were assessed using sleep habit questionnaires. The sleep midpoint was calculated as the halfway point between the bedtime and wake-up time. Restricted cubic splines and logistic regression analyses were performed to explore the association between sleep timing and hypertension.ResultsA significant nonlinear association was observed between bedtime (Poverall<0.001; Pnonlinear<0.001), wake-up time (Poverall=0.024; Pnonlinear=0.076), sleep midpoint (Poverall=0.002; Pnonlinear=0.005), and the prevalence of hypertension after adjusting for potential confounders. Multivariable logistic regression showed that both late (> 12:00AM and 23:01PM to 12:00AM) and early (≤ 22:00PM) bedtimes were associated with an increased risk of hypertension compared to bedtimes between 22:01PM and 23:00PM. In addition, individuals with late (> 7:00AM) and early (≤ 5:00AM) wake-up times had a higher prevalence of hypertension than those with wake-up times ranging between 5:01AM and 6:00AM. Delaying the sleep midpoint (> 3:00AM) was also associated with an increased risk of hypertension. Furthermore, no significant interaction effect was found in the subgroup analyses stratified by age, sex, or apnea-hypopnea index.ConclusionsOur findings identified a nonlinear association between sleep timing and hypertension. Individuals with both early and late sleep timing had a high prevalence of hypertension.

Combined effects of sleep timing and nighttime sleep duration on non-alcoholic fatty liver disease

BackgroundWhile short sleep duration is linked to higher risk of non-alcoholic fatty liver disease (NAFLD), the combined effects of sleep timing and sleep duration on NAFLD are less explored. MethodsIn this cross-sectional study of 39,471 participants from Beijing-Tianjin-Hebei region of China, self-reported sleep information and ultrasonography-diagnosed NAFLD were obtained from Jan 2018 to Jan 2020. Sleep timing was categorized based on sleep midpoint: early-type (before 2:00 AM), intermediate-type (2:00–2:30 AM), and late-type (after 2:30 AM). We used multivariable logistic regression to explore the relationship between sleep timing, duration, and NAFLD. We analyzed sleep midpoint and duration categorically and continuously, and conducted stratification analyses by age, sex, body mass index, hypertension, diabetes, and dyslipidemia. ResultsIntermediate-type (OR: 1.15, 95% confidence interval: 1.05–1.26) and late-type sleep timing (OR: 1.08, 1.00–1.16) were associated with higher NAFLD risk compared to early-type. Additionally, longer sleep duration was linked to lower risk (OR: 0.92, 0.90–0.95 per hour increase). Notably, intermediate to late-type sleepers with normal sleep duration (7 to <8 h) exhibited a 20% higher NAFLD risk compared to early-type sleepers with the same duration (OR: 1.20, 1.04–1.39). The increased NAFLD risk associated with intermediate to late sleep timing was particularly evident in men, hypertension, and prediabetes or diabetes participants. ConclusionsIntermediate to late sleep timing, even with normal sleep duration, is associated with increased NAFLD risk. These findings underscore the importance of considering both sleep timing and sleep duration for NAFLD prevention, especially in men and individuals with cardiometabolic conditions.

Analysis of inducement of benign paroxysmal positional vertigo

Objective:To analyze the related factors that may affect the onset of benign paroxysmal positional vertigo（BPPV）. Methods:Fifty BPPV patients treated in Department of Otolaryngology Head and Neck Surgery, Shanxi Provincial People's Hospital from May to September 2023 were selected as the case group, and 50 healthy adults were selected as the control group. Relevant information was collected by means of questionnaire survey and medical history inquiry. The two groups were compared in terms of sleep time, night sleep duration, wake times, underlying diseases（hypertension, diabetes, coronary heart disease, etc.） and negative emotional impact. Results:The proportion of male and female in the case group was 16% and 84%, and that in the control group was 20% and 80%. The mean age of the case group was（54.66±13.39） years old, and the mean age of the control group was（54.42±12.55） years old, ranging from 27 to 80 years old. The sleeping time of the case group was significantly later than that of the healthy group, and the difference was statistically significant（P<0.05）. The night sleep duration of the case group was shorter than that of the healthy group, the difference was statistically significant（P<0.05）. There was no significant difference in awakening times between the case group and the healthy group（P>0.05）. There were more patients in the case group with underlying diseases（54%） and affected by negative emotions（70%） than in the healthy group, and the difference was statistically significant（P<0.05）. Conclusion:Late sleep time, short sleep duration at night, accompanied by underlying diseases and negative emotions can affect the onset of BPPV.

Associations between actigraphy-measured sleep duration, continuity, and timing with mortality in the UK Biobank.

To examine the associations between sleep duration, continuity, timing, and mortality using actigraphy among adults. Data were from a cohort of 88 282 adults (40-69 years) in UK Biobank that wore a wrist-worn triaxial accelerometer for 7 days. Actigraphy data were processed to generate estimates of sleep duration and other sleep characteristics including wake after sleep onset (WASO), number of 5-minute awakenings, and midpoint for sleep onset/wake-up and the least active 5 hours (L5). Data were linked to mortality outcomes with follow-up to October 31, 2021. We implemented Cox models (hazard ratio, confidence intervals [HR, 95% CI]) to quantify sleep associations with mortality. Models were adjusted for demographics, lifestyle factors, and medical conditions. Over an average of 6.8 years 2973 deaths occurred (1700 cancer, 586 CVD deaths). Overall sleep duration was significantly associated with risk for all-cause (p < 0.01), cancer (p < 0.01), and CVD (p = 0.03) mortality. For example, when compared to sleep durations of 7.0 hrs/d, durations of 5 hrs/d were associated with a 29% higher risk for all-cause mortality (HR: 1.29 [1.09, 1.52]). WASO and number of awakenings were not associated with mortality. Individuals with L5 early or late midpoints (<2:30 or ≥ 3:30) had a ~20% higher risk for all-cause mortality, compared to those with intermediate L5 midpoints (3:00-3:29; p ≤ 0.01; e.g. HR ≥ 3:30: 1.19 [1.07, 1.32]). Shorter sleep duration and both early and late sleep timing were associated with a higher mortality risk. These findings reinforce the importance of public health efforts to promote healthy sleep patterns in adults.

The Relationship between Breakfast and Sleep and Cardiovascular Risk Factors.

Despite extensive research on the individual effects of breakfast and sleep on health outcomes, there has been limited investigation into their combined effects. We aimed to evaluate the relationship between breakfast-eating behavior and sleep timing on cardiovascular disease (CVD) risk factors. A total of 16,121 participants (6744 men and 9377 women) aged 19 years or older were selected from the Korea National Health and Nutrition Examination Surveys (2016-2018, 2021). We classified participants into four groups: early sleep + regular breakfast eaters (group 1), late sleep + regular breakfast eaters (group 2), early sleep + infrequent breakfast eaters (group 3), and late sleep + infrequent breakfast eaters (group 4). In men, group 4 had a lower prevalence of obesity than group 1 (OR 0.78, 95%CI 0.62-0.97), and groups 2, 3, and 4 had a higher prevalence of metabolic syndrome (MetS) than group 1 (OR 1.43, 1.62, and 1.47, respectively). In women, group 4 had a lower prevalence of dyslipidemia than group 1 (OR 0.59, 95%CI 0.44-0.80), and group 2 had a higher prevalence of MetS than group 1 (OR 1.24, 95%CI 1.03-1.50). The combination of skipping breakfast and late sleep timing was associated with the higher prevalence of MetS particularly in men. Moreover, the relationship between breakfast and sleep timing on CVD risk factors differed by sex and age group.

Sleep duration and timing are prospectively linked with insulin resistance during late adolescence.

The aim of this study was to evaluate whether short sleep duration or later sleep timing isa risk factor for insulin resistance (IR) in late adolescence. Mexico City adolescents enrolled in a longitudinal birth cohort (ELEMENT) took part in two study visits during peri-puberty that occurred approximately 2 years apart. IR was assessed with serum glucose and insulin. Four groups were defined using puberty-specific cutpoints: no IR over the follow-up period, transition from normal to IR, transition from IR to normal, and IR at both timepoints. Baseline sleep assessments were measured with 7-day wrist actigraphy. Multinomial logistic regression models were used to evaluate associations between sleep duration and timing with homeostatic model assessment of insulin resistance categories, adjusting for age, sex, and baseline pubertal status. Adolescents who were ≥ 1hour below the sleep duration recommendations-for-age were 2.74 times more likely to develop IR (95% CI: 1.0-7.4). Similarly, adolescents who were in the latest category of sleep midpoint (>4:33 a.m.) were more likely than those with earliest midpoints (1 a.m.-3a.m.) to develop IR (oddsratio=2.63, 95% CI: 1.0-6.7). Changes in adiposity over follow-up did not mediate sleep and IR. Insufficient sleep duration and late sleep timing were associated with development of IR over a 2-year period in late adolescence.

Associations between circadian disruption and cardiometabolic disease risk: A review.

The human circadian system plays a vital role in many physiological processes, and circadian rhythms are found in virtually all tissues and organs. The disruption of circadian rhythms may lead to adverse health outcomes. Evidence from recent population-based studies was reviewed because they represent real-world behavior and can be useful in developing future studies to reduce the risk of adverse health conditions, including cardiovascular diseases, obesity, and diabetes mellitus, which may occur because ofcircadian disruption. An electronic search in PubMed and Web of Science (2012-2022) was performed. Selected articles were based on specific inclusion and exclusion criteria. Five factors that may disrupt circadian rhythm alignment are discussed: shift work, late chronotype, late sleep timing, sleep irregularity, and late meal timing. Evidence from observational studies of these circadian disruptors suggests potential detrimental effects on cardiometabolic health, including higher BMI/obesity, higher blood pressure, greater dyslipidemia, greater inflammation, and diabetes. Future research should identify the specific underlying pathways in order to mitigate the health consequences of shift work. Furthermore, optimal sleep and mealtimes for metabolic health can be explored in intervention studies. Lastly, it is important that the timing of external environmental cues (such as light) and behaviors that influence circadian rhythms are managed.

Children’s Sleep and Externalizing Problems: A Day-to-day Multilevel Modeling Approach

ABSTRACT Background Sleep problems and externalizing problems tend to be positively associated, but the direction of this association is unclear. Method Day-to-day associations between sleep and behavior were examined in children (N = 22) ages 3–8 with clinical levels of externalizing problems. These children were enrolled in Parent Management Training and behavioral sleep intervention. During assessments before and after treatment, children wore actigraphs for seven days and parents concurrently completed sleep diaries and daily tallies of noncompliance, aggression, and tantrums. Multilevel modeling was used to account for the nested structure of the data, at the day-to-day level (level 1), within assessment points (level 2), and within children (level 3). Results Late sleep timing and fragmentation were predictive of next-day noncompliance and tantrums, respectively. There were fewer associations for a given day’s behavior predicting that night’s sleep, although children who showed more aggression and noncompliance at baseline tended to have later bedtimes and sleep onset times compared to other children.

Evening Light Intensity and Phase Delay of the Circadian Clock in Early Childhood.

Late sleep timing is prevalent in early childhood and a risk factor for poor behavioral and health outcomes. Sleep timing is influenced by the phase of the circadian clock, with later circadian timing linked to delayed sleep onset in young children. Light is the strongest zeitgeber of circadian timing and, in adults, evening light produces circadian phase delay in an intensity-dependent manner. The intensity-dependent circadian phase-shifting response to evening light in children, however, is currently unknown. In the present study, 33 healthy, good-sleeping children aged 3.0 to 4.9 years (M = 4.14 years, 39% male) completed a 10-day between-subjects protocol. Following 7 days of a stable sleep schedule, an in-home dim-light circadian assessment was performed. Children remained in dim-light across 3 days (55 h), with salivary melatonin collected in regular intervals throughout each evening. Phase-shifting effects of light exposure were determined via changes in the timing of the dim-light melatonin onset (DLMO) prior to (Day 8) and following (Day 10) a light exposure stimulus. On Day 9, children were exposed to a 1 h light stimulus in the hour before their habitual bedtime. Each child was randomly assigned to one intensity between 5 and 5000 lux (4.5-3276 melanopic EDI). Across light intensities, children showed significant circadian phase delays, with an average phase delay of 56.1 min (SD = 33.6 min), and large inter-individual variability. No relationship between light intensity and magnitude of the phase shift was observed. However, a greater percentage of melatonin suppression during the light exposure was associated with a greater phase delay (r = -0.73, p < 0.01). These findings demonstrate that some young children may be highly sensitive to light exposure in the hour before bedtime and suggest that the home lighting environment and its impact on circadian timing should be considered a possible contributor to behavioral sleep difficulties.

0201 Sleep duration and timing is prospectively linked with increases in insulin resistance over late adolescence

Abstract Introduction During puberty, adolescents experience a period of transient insulin resistance (IR) that normalizes upon full maturation. Yet, IR continues to rise for some adolescents, increasing metabolic disease and type 2 diabetes risk in adulthood. Whether short sleep duration and/or later sleep timing are risk factors for persistently increasing IR in late adolescence has not been explored. Methods The study population includes 362 adolescents from Mexico City enrolled in a longitudinal birth cohort (ELEMENT study). Beginning in 2015, when participants were between the ages of 9 and 17, there were 2 clinic visits that occurred approximately 2 years apart. During the visit, a fasting blood sample and anthropometric measurements were taken. Insulin resistance was assessed with glucose and insulin via HOMA-IR. Four groups were defined using puberty-specific cutpoints for IR: normal HOMA-IR over the follow-up period (reference), transition from normal to IR, transition from IR to normal, and IR at both time points. Baseline sleep assessments (sleep duration, timing, and variability of both duration and timing) were measured with 7-day actigraphy. Multinomial logistic regression models were used to evaluate associations between sleep duration and timing with HOMA-IR categories, adjusting for age, sex, and baseline pubertal status Results Seventeen percent of the sample developed insulin resistance over the follow-up period. Adolescents ≥1 hour below the sleep duration recommendations-for-age were over twice as likely to be in the group that developed IR compared to the normal group (95% CI 1.1, .9; P for trend=0.03). Similarly, adolescents who had a sleep midpoint later than 4:36 AM were 2.77 times as likely to be in the increasing HOMA-IR category (95% CI 1.0, 7.5; P for trend=0.05). Interestingly, there was no evidence that changes in adiposity over follow-up mediated associations between sleep and insulin resistance. Conclusion Insufficient sleep duration and late sleep timing were independently associated with development of IR over a 2-year period in peri-puberty. Adequate sleep during the pubertal period may promote metabolic health into young adulthood, independent of any changes in adiposity. Support (If Any) Dr. Jansen is supported by K01HL151673. The study is supported by P01 ES02284401.

Abstract EP61: Short Sleep Duration, Late Sleep Timing, And Late Eating Timing: A Trilogy Of Behavioral Risk Factors For High Blood Pressure?

Introduction: Short sleep duration (&lt;7 h/night) is a risk factor for hypertension and other cardiovascular diseases (CVD). Not clear is if delayed timing of sleep or eating behaviors adds to this risk. We tested the hypothesis that later sleep and eating timing would be associated with higher blood pressure (BP), and that adults with short sleep + late behavior timing would have the highest BP vs those with one (short sleep OR late timing) or no risk behaviors (adequate sleep + early timing). Methods: Over a 14-day period, 30 healthy, non-shift working adults wore wrist actigraphs to evaluate sleep duration and onset timing, and completed image-assisted diet records to estimate eating onset (time of first caloric intake after awakening) and offset (time of last caloric intake before sleep). Fasted morning systolic (SBP) and diastolic BP (DBP) were obtained. Regression models of SBP and DBP tested associations with sleep onset, eating onset, and eating offset. Sleep duration (&lt;7 vs ≥7h) and behavior timing metrics (median split) were dichotomized, and ANOVAs compared BP between sleep duration + behavior timing groups. Results: Participants were 28±7y, 43% male, BMI 23.9±2.6 kg/m 2 , and BP 114±10/70±7 mmHg. Sleep duration was 6.8±0.8 h, sleep onset 23:45±1.3 h, eating onset 08:49±1.5 h, and eating offset 20:40±1.2 h. Independent of age and sex, later sleep onset was associated with higher SBP (B= 3.0±1.3 mmHg/h, p =0.03) and DBP (B= 2.5±0.9 mmHg/h, p =0.01). Later eating onset was associated with higher DBP (B= 2.1±0.9 mmHg/h, p =0.03), and later offset with higher SBP (B= 4.1±1.4 mmHg/h, p &lt;0.01) and DBP (B= 3.3±1.0 mmHg/h, p &lt;0.01). When grouped according to sleep duration and eating offset, short sleep + late timing participants exhibited higher DBP vs adequate sleep + early timing (75±7 vs 67±7, p =0.03) and tended to exhibit higher SBP and DBP vs short sleep OR late timing (both p =0.07). Conclusion: These data indicate later sleep and eating timing, especially in the setting of short sleep, exemplifies a chrono-behavioral phenotype of CVD risk.

Effects of sleep habits on acute myocardial infarction risk and severity of coronary artery disease in Chinese population

BackgroundGrowing evidence indicates that poor sleep harms health. Early to bed and early to rise is considered as a healthy lifestyle in Chinese population. The current study aimed to examine the effects of sleep habits on acute myocardial infarction (AMI) risk and severity of coronary artery disease (CAD) in Chinese population from two centers.MethodsA total of 873 patients including 314 AMI cases and 559 controls were recruited from the inpatient cardiology department of the Affiliated Jiangning Hospital and the First Affiliated Hospital of Nanjing Medical University. 559 controls included 395 CAD cases and 164 non-CAD cases. We used a 17-item sleep factors questionnaire (SFQ) to evaluate sleep habits comprehensively by face-to-face interview. The severity of CAD was assessed by Gensini score in AMI and CAD groups. The effects of sleep factors on AMI risk and Gensini score were examined by unconditional logistic regression.ResultsAfter mutually adjustment for other sleep factors and demographic characteristics, the timing of sleep (24:00 and after) and morning waking (after 7:00) and sleep duration (< 6 h) were associated with increased risk of AMI (OR = 4.005, P < 0.001, OR = 2.544, P = 0.011 and OR = 2.968, P < 0.001, respectively). Lower level of light exposure at night was correlated with reduced risk of AMI (OR = 0.243, P = 0.009). In subgroup analysis by age, both late sleep timing and short sleep duration were associated with increased risk of AMI regardless of age. In subjects with age ≤ 65 years, daytime napping was related to reduced risk of AMI (OR = 0.645, P = 0.046). In subjects with age > 65 years, the frequency of night-time waking (3 times) was associated with increased risk of AMI (OR = 3.467, P = 0.035). Short sleep duration was correlated with increased risk of high Gensini score (OR = 2.374, P < 0.001).ConclusionSleep insufficiency is an important risk factor both for AMI risk and CAD severity. Late sleeping is also associated with increased risk of AMI. In young and middle-aged people, regular naps may have a protective effect.Graphic abstract

Relationship between work context and sleep problems of high school teachers

Objective: The teaching function is related to work overload and health problems, including sleep problems. However, is there a relationship between sleep problems and aspects of work? In view of this, this study aimed to assess the relationship between the work context, the quality of sleep and the daytime sleepiness of teachers from public schools in Rio Grande do Norte (RN). Methodology: This study was conducted in 9 schools with 61 teachers of both genders who filled the work context assessment scale, the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Results and Discussion: The majority evaluated Working Conditions and Work Organization as critical/severe, and half of them considered Socio-Professional Relations as critical/severe. Poor sleep quality was observed in 69% of teachers, regardless of gender and excessive daytime sleepiness was observed in 49% of teachers, most often in women (55%) compared to men. Nevertheless, there was no significant relationship between work context and sleep problems. In relation to sleep schedule, it was observed that teachers present late sleep time (23: 26 ± 1: 25h) and early wake up time (6: 06 ± 1: 16h) which may have resulted in short sleep duration (6: 10 ± 1: 07h). Conclusion: These results demonstrate that, in general, public school teachers in RN present complaints related to the work context and sleep problems. However, studies with a more representative sample are needed to assess as the factors related to the work context may be contributing to sleep problems. Furthermore, there is a need to create spaces for discussion with teachers in order to improve the work context and public policies aimed at education.

Social Jetlag and Excessive Daytime Sleepiness from a Sample of Russian Children and Adolescents.

PurposeInsufficient nocturnal sleep is a primary source of excessive daytime sleepiness. Most previous research has focused on the disparity between sleep demands and study start times in adolescents. Fewer studies have focused on elementary schoolchildren. We hypothesize that late sleep timing is connected to excessive daytime sleepiness in a sample of Russian children and adolescents. The major goals of our study were to evaluate excessive daytime sleepiness in Russian schoolchildren and adolescents using the Russian version of the Pediatric Daytime Sleepiness Scale (PDSS) and to estimate its relationship with sleep-wake parameters using the Munich Chronotype Questionnaire (MCTQ).Materials and MethodsStudent subjects were from public educational facilities in the Republic of Karelia. They completed both the PDSS and the Munich Chronotype Questionnaire to estimate sleep parameters and chronotype (MSFsc). Five hundred and eleven students provided data for the PDSS and sleep-wake variables, and 479 for the full MCTQ data.ResultsThe overall prevalence of Excessive Daytime Sleepiness (EDS) in our sample was 18%. The total PDSS score was inversely correlated with sleep length on school nights and was independent of respondents’ sex. Higher PDSS scores were associated with later bedtimes on school days and free days, and shorter sleep duration on school days. Late chronotype and more pronounced social jetlag were both positively correlated with high PDSS scores. A negative correlation was found between chronotype and the duration of the sleep period on weekdays (p < 0.001) and a positive correlation was found on weekends (p < 0.001). Longer average sleep duration was positively related to less daytime sleepiness.ConclusionThis study suggests that excessive daytime sleepiness is chronotype-dependent. School start times could be shifted to a later hour to prolong sleep and reduce EDS.

661 Chronotype, Mood, and Diabetes-Related Distress in Adults with Type 2 Diabetes

Abstract Introduction Chronotype refers to an individual’s preferred timing of sleep and wakefulness, which can be classified as ‘normal’ or ‘late’ chronotypes. The purpose of this study was to examine whether late sleep timing was associated with impaired mood and diabetes-related distress in persons with type 2 diabetes (T2D). Methods The study is a secondary analysis of pooled cross-sectional baseline data from two studies of treatment of obstructive sleep apnea (R01-DK96028) and insomnia (K24-NR016685) in persons with T2D. Sleep timing was measured by the bedtime from a 7-day sleep diary. “Normal” sleep timing was defined as bedtime between 9PM to 12AM ≥ 85% per week. “Late” sleep timing as bedtime after 12AM with normal sleep timing &amp;lt; 85% per week. Other sleep variables evaluated were sleep duration, daytime sleepiness (Epworth Sleepiness Scale [ESS]), and OSA severity (apnea-hypopnea index [AHI]). The Profiles of Mood States measured Total Mood Disturbance (TMD) and the subscales of Tension-Anxiety (T-A), Depression-Dejection (D-D), Anger-Hostility (A-H), Vigor-Activity (V-A), Fatigue-Inertia (F-I), and Confusion-Bewilderment (C-B). Diabetes-related distress was measured by the Problem Areas in Diabetes (PAID). Hierarchical multiple regression was performed to determine whether sleep timing was associated with mood and diabetes-related distress. Results The sample (N=296) had 61% with late sleep timing (n=181). Persons with normal vs late sleep timing were similar in age, sex, race, and education (p &amp;gt;.05). Persons with late sleep timing were less likely to be partnered, had shorter sleep duration and greater mood impairment (TMD and T-A, D-D, A-H, C-B subscales) than those with normal timing (all p values &amp;lt;.05); there was no significant difference by sleep timing in PAID scores (p=.256). Hierarchical regression analyses adjusting for demographics (age, sex, race, marital status, education level), clinical (HbA1c, BMI), and sleep variables (sleep duration, ESS, AHI) revealed that late sleep timing was not significantly associated with impaired mood (TMD and subscales) or PAID. However, ESS was statistically significant in predicting greater TMD (β=.310, p &amp;lt;.001), mood subscales (all p-values &amp;lt;.05) and PAID (β =.222, p &amp;lt;.001). Conclusion Daytime sleepiness, not late sleep timing, is a significant sleep-related symptom for increased mood impairment and diabetes-related distress in persons with T2D. Support (if any):

The relationship of sleep duration and quality to energy expenditure and physical activity in children.

Shorter sleep duration has been linked to the risk for obesity in children. The pathways linking sleep duration and quality to the risk of obesity are unclear, particularly the effect of sleep on energetics. We investigated the relationship between sleep duration, quality and timing in children, to the basal metabolic rate (BMR), total energy expenditure (TEE) and physical activity (PA). Fifty nine children in two age-groups (5-11 and 12-18 years) underwent evaluation of body composition (DXA), BMR in a room calorimeter, free-living TEE by doubly labelled water method, sleep and PA (7-day Actiheart monitor) during school break. Sleep duration contributed to the variance in BMR (β = 0.11, P = .009) after adjusting for age-group, sex, lean and fat mass, but not to the variance in TEE. Late sleep timing was related to lower PA. In the younger age-group, children who met recommended sleep duration on ≥50% of the 7 days had higher light PA (P = .03) and lower sedentary time (P = .009). Suboptimal sleep is associated with lower BMR, lower PA, and higher sedentary behaviours in young children. Prospective studies are needed to confirm if insufficient sleep duration or late sleep timing contribute to obesity risk by increasing sedentary behaviours and decreasing BMR.

Sleep timing, sleep consistency, and health in adults: a systematic review.

The objective of this systematic review was to examine the associations between sleep timing (e.g., bedtime/wake-up time, midpoint of sleep), sleep consistency/regularity (e.g., intra-individual variability in sleep duration, social jetlag, catch-up sleep), and health outcomes in adults aged 18 years and older. Four electronic databases were searched in December 2018 for articles published in the previous 10 years. Fourteen health outcomes were examined. A total of 41 articles, including 92 340 unique participants from 14 countries, met inclusion criteria. Sleep was assessed objectively in 37% of studies and subjectively in 63% of studies. Findings suggest that later sleep timing and greater sleep variability were generally associated with adverse health outcomes. However, because most studies reported linear associations, it was not possible to identify thresholds for "late sleep timing" or "large sleep variability". In addition, social jetlag was associated with adverse health outcomes, while weekend catch-up sleep was associated with better health outcomes. The quality of evidence ranged from "very low" to "moderate" across study designs and health outcomes using GRADE. In conclusion, the available evidence supports that earlier sleep timing and regularity in sleep patterns with consistent bedtimes and wake-up times are favourably associated with health. (PROSPERO registration no.: CRD42019119534.) Novelty This is the first systematic review to examine the influence of sleep timing and sleep consistency on health outcomes. Later sleep timing and greater variability in sleep are both associated with adverse health outcomes in adults. Regularity in sleep patterns with consistent bedtimes and wake-up times should be encouraged.

Impact of sleep behaviors on social and emotional problems in three-year-old children born prematurely

BackgroundChildhood sleep problems have been associated with a number of negative health outcomes, but there is limited data on the relationship between sleep problems and social and emotional problems in preterm babies. ObjectiveThe aim of this study was to investigate sleep habits and the relationship between sleep problems and social and emotional problems in preterm infants with a corrected age of three years old. MethodThe study included 40 preterm children and 40 full-term children. In order to evaluate the sleep habits and social and emotional problems of the children, their mothers completed the Brief Infant Sleep Questionnaire (BISQ) and the Brief Infant Toddler Social Emotional Assessment Scale (BITSEA) form. ResultsIt has been found that preterm children had longer sleeplessness at night than full-term children and the frequency of night awakening was also higher in full-term children. There was no difference between preterm and full-term children in terms of sleep duration, sleep location and methods of falling asleep. Although there was no difference between the two groups in the BITSEA problem scores, the BITSEA competence scores were significantly lower in preterm children compared to full-term children. In addition, considering the relationship between sleep behaviors and social and emotional problems in preterm infants, a significant correlation was found between short sleep duration at night, total sleep duration, and lower BITSEA competence scores. A late sleep time and social and emotional subclinical problem scores were also found to be correlated. ConclusionAccording to the results of this study, no significant difference was found in terms of sleep behaviors between preterm and full-term three-year-old children. However, BITSEA competence scores were lower in preterm children and an association has been found between sleep behaviors and social and emotional problems.

Sleep across early childhood: implications for internalizing and externalizing problems, socioemotional skills, and cognitive and academic abilities in preschool.

Sleep is thought to be important for behavioral and cognitive development. However, much of the prior research on sleep's role in behavioral/cognitive development has relied upon self-report measures and cross-sectional designs. The current study examined how early childhood sleep, measured actigraphically, was developmentally associated with child functioning at 54months. Emphasis was on functioning at preschool, a crucial setting for the emergence of psychopathology. Participants included 119 children assessed longitudinally at 30, 36, 42, and 54months. We examined correlations between child sleep and adjustment across three domains: behavioral adjustment (i.e., internalizing and externalizing problems), socioemotional skills, and academic/cognitive abilities. We further probed consistent associations with growth curve modeling. Internalizing problems were associated with sleep variability, and cognitive and academic abilities were associated with sleep timing. Growth curve analysis suggested that children with more variable sleep at 30months had higher teacher-reported internalizing problems in preschool and that children with later sleep timing at 30months had poorer cognitive and academic skills at 54months. However, changes in sleep from 30 to 54months were not associated with any of the domains of adjustment. Findings indicate that objectively measured sleep variability and late sleep timing in toddlerhood are associated with higher levels of internalizing problems and poorer academic/cognitive abilities in preschool.