Association between neonatal phototherapy and sleep: The Japan Environment and Children's Study.

This observational cohort study aimed to evaluate the association between the duration of neonatal phototherapy and sleep-and-wakefulness states at 1 month, 1.5 years, and 3 years of age. We analysed data from 77,876 infants using the Japan Environment and Children's Study, a nationwide birth cohort study. The participants were divided into three groups: no phototherapy, short phototherapy (1-24 h), and long phototherapy (>24 h). Multiple regression analysis was performed to assess the effect of phototherapy duration on infant sleep at each age after adjusting for potential risk factors. A longer duration of phototherapy was associated with a shorter sleep time over 24 h at 1 month of age (ß, -0.62; SE, -0.77 to -0.47) when compared with a shorter duration of, or no, phototherapy, following the adjustment of confounding factors. Contrastingly, the short duration group, when compared with the no phototherapy group, was associated with later sleep onset (ß, 0.04; SE, 0.00-0.08) and later sleep offset (ß, 0.05; SE, 0.01-0.09) at 1.5 years of age. We concluded that the duration of phototherapy may be transiently associated with sleep duration in infants, as emphasised by the shortening of the total sleep time per 24 h at 1 month of age.

The association between self-reported nocturnal sleep duration, irregularity in daily energy intake and diet quality in a sample of Iranian adults.

OBJECTIVE: Evidence on the relationship between sleep duration and irregularity in daily energy intake with diet quality in Iranian adults is scarce. We aimed to evaluate the association of sleep duration with diet quality and irregularity in daily energy intake. DESIGN: This is a cross-sectional study. SETTING: The study was performed in healthcare centres in Tehran. PARTICIPANTS: 739 adults aged 20-59 years were recruited. Dietary intake was assessed by a FFQ and three 24-h dietary recalls. Diet quality was assessed using the Healthy Eating Index-2015 (HEI-2015). An irregularity score of daily energy intake was calculated based on the deviation from the 3-d mean energy intake. Sleep duration was estimated using self-reported nocturnal sleep duration by each person. RESULTS: The mean age of the study participants was 44·4 ± 10·7 years; 70 % were women. The mean nocturnal sleep duration, HEI score and irregularity score were 6·7 ± 1·22 h/d, 52·5 ± 8·55 and 22·9 + 19, respectively. After adjusting for potential confounders, sleep duration was not associated with adherence to HEI-2015 (OR: 1·16; 95 % CI 0·77, 1·74). Longer sleep duration was marginally associated with a lower odd of irregularity in daily energy intake. However, after adjustment for various confounders, this association was not significant (OR: 0·82; 95 % CI 0·50, 1·33; Ptrend = 0·45). No significant interaction was observed between sleep duration and irregularity in daily energy intake in relation to adherence to HEI-2015 (Pinteraction = 0·48). CONCLUSIONS: We found that sleep duration was not associated with adherence to HEI-2015 and irregularity in daily energy intake. Further prospective studies are warranted.

Changes in self-reported sleep duration with age - a 36-year longitudinal study of Finnish adults.

BACKGROUND: Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep duration in a population-based cohort. METHODS: Members of the Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals, response rate 89%, mean age 36 years), 1981 (24,535, 84%, 41 years), 1990 (12,450, 77%, 44 years), and 2011 (8334, 72%, 60 years). Weibull regression models were used to model the effects of follow-up time and age simultaneously. RESULTS: Sleep duration has decreased in all adult age groups and in both genders. The mean duration was in men 7.57 h in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5 min in men and 0.9 in women per year of follow-up. In the age-group 18-34 years, mean sleep length was 7.69 h in 1975 and 7.53 in 1990. Among 35-54-year-old it was 7.57 h in 1975 and 7.34 in 2011, and in the age group of 55+ year olds 7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 min or about 0.6 min per year of follow-up. CONCLUSIONS: There has been a slight decrease in mean sleep duration during the 36-year follow-up. Although the sleep duration was longer in 1970s and 1980s, the probable main cause for the change in this study population is the effect of aging.

Tracing diurnal differences in brain anatomy with voxel-based morphometry - associations with sleep characteristics.

Multiple aspects of brain functioning, including arousal, motivation, and cognitive performance, are governed by circadian rhythmicity. Although the recent rise in the use of magnetic resonance imaging (MRI) has enabled investigations into the macroscopic correlates of the diurnal brain processes, neuroanatomical studies are scarce. The current work investigated how time-of-day (TOD) impacts white (WM) and grey matter (GM) volumes using voxel-based morphometry (VBM) in a large dataset (N = 72) divided into two equal, comparable subsamples to assess the replicability of effects. Furthermore, we aimed to assess how the magnitude of these diurnal differences was related to actigraphy-derived indices of sleep health. The results extend the current knowledge by reporting that TOD is predominantly associated with regional WM volume decreases. Additionally, alongside corroborating previously observed volumetric GM decreases, we provide the first evidence for positive TOD effects. Higher replicability was observed for WM, with the only two replicated GM clusters being volumetric increases in the amygdala and hippocampus, and decreases in the retrosplenial cortex, with the latter more pronounced in individuals with shorter sleep times. These findings implicate the existence of region-specific mechanisms behind GM effects, which might be related to cognitive processes taking place during wakefulness and homeostatic sleep pressure.

Genetic factors in evolution of sleep length--a longitudinal twin study in Finnish adults.

Genetic factors affect many aspects of sleep, such as sleep length. We investigated the contribution of genetic factors to stability and change of sleep length among adults over a 15-year period. In this representative follow-up study we used the Finnish Twin Cohort as the study population. Questionnaire surveys were performed in 1975 (response rate 89%, 11,041 twin pairs; age ≥18 years), 1981 (84%, 9323; ≥24 years) and 1990 (77%, 4507; 33-60 years). Sleep was categorized as short (<7 h), average or long (>8 h). Pairwise similarity in monozygotic and dizygotic pairs was examined at each survey by age group and sex. Quantitative genetic modelling was used to estimate cross-sectional and longitudinal genetic effects. The proportion of variance in sleep length at one point in time that was accounted for by genetic effects was very stable over the study period, being 0.31 in 1975, 0.32 in 1981 and 0.30 in 1990. Longitudinal genetic modelling indicated that the correlations of genetic effects between the three measurement points were high: 0.85 between 1975 and 1981; 0.93 between 1981 and 1990; and 0.76 between 1975 and 1990. Despite a high contribution of environmental effects, their correlations over time were modest: 0.31 between 1975 and 1981; 0.33 between 1981 and 1990; and 0.18 between 1975 and 1990. In conclusion, genetic factors have a modest but stable effect on the evolution of sleep length over a long time span in adults. Multiple measures are a more robust basis for genetic analyses than a single cross-sectional measure.

Longitudinal interplays between basic psychological need satisfaction and sleep among older adults in China.

RATIONALE: Older people's sleep and associated health implications loom large in aging societies. Self-determination theory indicates lagged or immediate interplays between subjective sleep and satisfaction of basic psychological needs (for autonomy, relatedness, and competence). However, little is known about their longitudinal dynamics in later life. OBJECTIVE: This study investigated longitudinal reciprocities between satisfaction of basic psychological needs and subjective sleep for older people and controlled for six sociodemographic and health-related covariates. METHOD: Three waves of data from the Chinese Longitudinal Healthy Longevity Survey (2011, 2014, and 2017) were analyzed using Structural Equation Modelling (N = 2,834, 52.68% women, Mean age = 78.36). Participants reported sleep quality and duration, satisfaction of basic psychological needs, and sociodemographic and health characteristics. Four competing models were examined: Model A conceptualized lagged effects of sleep on need satisfaction and vice versa (i.e. cross-lagged design), Model B described immediate needs' effects on sleep but lagged opposite effects, Model C reversed Model B's specifications, and Model D portrayed concurrent feedback loops. RESULTS: It was found that satisfaction of psychological needs and sleep quality declined over the seven-year span, but sleep length only fluctuated trivially. All models fitted the data well, where better sleep quality consistently predicted higher levels of need satisfaction, especially for relatedness and competence. Sleep interacted most robustly with relatedness: Models A, B, and C revealed positive lagged or immediate reciprocities between sleep quality and relatedness, and Model D yielded negative feedback loops between sleep length and relatedness. CONCLUSIONS: The study identified longitudinal immediate or lagged interplays between need satisfaction and sleep for older people, especially concerning relatedness need. Implementation of need-supportive interventions and promotion of healthy sleep habits are necessary for healthy aging.

A cross-sectional study on sleep length, quality, and mobile phone use among Moroccan adolescents.

Introduction: sleep plays an important role in learning and the formation of memories among adolescents, and lack of sleep affects their health, safety, and school performance, especially in the age of mobile phones. This study´s aim was to investigate sleep length and sleep quality among Moroccan adolescents and assess their relationship to mobile phone use. Methods: the population of this cross-sectional study included all the adolescent students aged 12-20 years, living in the Settat region, Morocco. We used proportionate stratified random sampling to select 800 participants from schools in the region. The researchers used a self-developed questionnaire coupled with the Pittsburgh Sleep Quality Index questionnaire to measure sleep length and evaluate sleep quality, respectively. We performed the statistical analysis using a combination of parametric and nonparametric tests to assess sleep length variables and PSQI score relationship to different independent variables. Results: participation rate was 91.2% (n = 730). The mean total sleep time was 8.01 hrs (SD = 1.46 hrs). Wake-up time was 8:17 a.m. (SD = 2.33 hrs), among late-night mobile phone users and 8:00 a.m. (SD = 2.11 hrs) among non-users. Overall, 76.7% of students from rural schools and 66.5% of students from urban schools reported poor sleep quality (p-value = 0.002). Most late-night mobile phone users (78%; p-value = 0.001) had poor sleep quality. Sleep quality decreased by age and in physically and psychologically unhealthy adolescents (p-value <0.001). Conclusion: a high percentage of adolescents in the Settat region suffer from poor sleep quality and sleep deprivation, especially among those who use cell phones before going to sleep. We advise parents and the Moroccan education system to promote good sleep habits and reduce the use of such devices in the bedroom by adolescents.

Sleep Duration and Timing in the Medium- to Long-Term Post-Bariatric Surgery.

Sleep duration improves short-term following bariatric surgery; however, little is known about its association with bodyweight medium- to long-term post-surgery. The purpose of this study was to describe sleep duration and its relationship with BMI and body composition. Forty-nine individuals, with a BMI of 36.6 ± 9.8 kg/m2, regained 26.4 ± 17.8% of their lost weight 9.5 ± 3.3 years post-surgery (range 3-16 years). Sleep logs and ActivPAL3 accelerometers were used to assess sleep duration. Participants averaged 7.9 ± 1.6 h/day and 8.5 ± 1.7 h/day of sleep for weekdays and weekends, respectively (P < 0.01). A positive association between delta weekend-weekday sleep timing midpoint with BMI (ß = 0.03, 95% CI = 0.01, 0.06; P = 0.01) was noted in the multivariable-adjusted model. On average, this sample achieved recommended sleep durations medium- to long-term post-surgery. Having an earlier sleep timing midpoint during the weekend may be associated with lower BMI.

Self-reported nocturnal sleep duration and glycosylated hemoglobin A in the Study of Cardiovascular Risks in Adolescents (ERICA).

OBJECTIVE: At present, epidemiologic studies regarding the relationship between sleep duration and glucose metabolism in adolescents are scarce. The objective was to investigate the association between self-reported nocturnal sleep duration and glycosylated hemoglobin A in 12- to 17-year-old Brazilian adolescents. PATIENTS/METHODS: A school-based multicenter cross-sectional study was carried out in private and public schools from 273 municipalities with more than 100,000 inhabitants. The final sample comprised 24,923 adolescents. A self-administered questionnaire was used. Blood tests included glucose, insulin, glycosylated hemoglobin A and serum lipids. Age, sex, skin color, school type, body mass index (BMI), physical activity, and Brazilian regions were studied as possible effect modifiers and/or confounders using linear regression. RESULTS: A significant positive association was found between more than 12 h of nocturnal sleep and glycosylated hemoglobin A in two Brazilian regions: Southeast and South, even after adjustment for age, sex, skin color, and BMI (coefficients of 0.142 and 0.339, respectively). No association was found with nocturnal sleep duration <7 h. CONCLUSION: Notably, a significant positive relationship was found between more than 12 h of nocturnal sleep duration and glycosylated hemoglobin A in two Brazilian regions. The specific pubertal sleep curtailment can be a compensatory mechanism for dealing with the insulin resistance during adolescence. Those that escape from this regulatory strategy and sleep longer than the adequate duration, break down this balance and tend to damage their glucose metabolism. To our knowledge, this is the first large scale study, of the association between sleep duration and glucose metabolism in adolescents.

Respiratory symptoms are more common among short sleepers independent of obesity.

INTRODUCTION: Sleep length has been associated with obesity and various adverse health outcomes. The possible association of sleep length and respiratory symptoms has not been previously described. The aim of this study was to investigate the association between sleep length and respiratory symptoms and whether such an association existed independent of obesity. METHODS: This is a multicentre, cross-sectional, population-based study performed in 23 centres in 10 different countries. Participants (n=5079, 52.3% males) were adults in the third follow-up of the European Community Respiratory Health Survey III. The mean±SD age was 54.2±7.1 (age range 39-67 years). Information was collected on general and respiratory health and sleep characteristics. RESULTS: The mean reported nighttime sleep duration was 6.9±1.0 hours. Short sleepers (<6 hours per night) were n=387 (7.6%) and long sleepers (≥9 hours per night) were n=271 (4.3%). Short sleepers were significantly more likely to report all respiratory symptoms (wheezing, waking up with chest tightness, shortness of breath, coughing, phlegm and bronchitis) except asthma after adjusting for age, gender, body mass index (BMI), centre, marital status, exercise and smoking. Excluding BMI from the model covariates did not affect the results. Short sleep was related to 11 out of 16 respiratory and nasal symptoms among subjects with BMI ≥30 and 9 out of 16 symptoms among subjects with BMI <30. Much fewer symptoms were related to long sleep, both for subjects with BMI <30 and ≥30. CONCLUSIONS: Our results show that short sleep duration is associated with many common respiratory symptoms, and this relationship is independent of obesity.

Sleep Duration and Adiposity in Early Childhood: Evidence for Bidirectional Associations from the Born in Bradford Study.

Study Objectives: To examine independent associations of sleep duration with total and abdominal adiposity, and the bidirectionality of these associations, in a young biethnic sample of children from a disadvantaged location. Methods: Child sleep duration (h/day) was parent-reported by questionnaire and indices of total (body weight, body mass index, percent body fat (%BF), sum of skinfolds) and abdominal adiposity (waist circumference) were measured using standard anthropometric procedures at approximately 12, 18, 24, and 36 months of age in 1,338 children (58% South Asian; 42% White). Mixed effects models were used to quantify independent associations (expressed as standardised ß-coefficients (95% confidence interval (CI)) of sleep duration with adiposity indices using data from all four time-points. Factors considered for adjustment in models included basic demographics, pregnancy and birth characteristics, and lifestyle behaviours. Results: With the exception of the sum of skinfolds, sleep duration was inversely and independently associated with indices of total and abdominal adiposity in South Asian children. For example, one standard deviation (SD) higher sleep duration was associated with reduced %BF by -0.029 (95% CI: -0.053, -0.0043) SDs. Higher adiposity was also independently associated with shorter sleep duration in South Asian children (for example, %BF: ß = -0.10 (-0.16, -0.028) SDs). There were no significant associations in White children. Conclusions: Associations between sleep duration and adiposity are bidirectional and independent among South Asian children from a disadvantaged location. The results highlight the importance of considering adiposity as both a determinant of decreased sleep and a potential consequence.

Sleep patterns and their association with depression and behavior problems among Chinese adolescents in different grades.

We aimed to examine sleep patterns and their association with depression and behavior problems among Chinese adolescents in different grades. A cross-sectional study was conducted in 10 cities of mainland China. A total of 8,998 Chinese adolescents (49.3% males) aged 9-20 years completed a self-administered questionnaire that included questions on sleep patterns, depressive symptoms, behavior problems, and demographic characteristics. The percentage of adolescents who slept less than 7 hr on weekdays increased with grade, while the percentage of adolescents who slept less than 7 hr on weekends remained the same. The gap in sleep length between weekdays and weekends increased from 0.6 hr in grade 5 to 2.3 hr in Grade 12. The regression analysis showed that poor sleep habits were linked to greater emotional and behavioral problems. The associations of sleep length with those problems differed by symptom and grade. Sleeping less related to depression in all grades. More behavior problems were observed in primary school students who had less sleep and in senior high school students who had more sleep than their peers. The preference for going to bed late stably related to both adolescent depression and behavior problems in all grades, although it posed a greater risk for students in higher grades.

Circadian preferences and sleep in 15- to 20-year old Finnish students.

PURPOSE: Despite progress in research concerning adolescent and young adult sleep and circadian preferences, several aspects have remained unexamined. This study explored gender and diurnal rhythms in relation to several sleep-related factors: sleep duration, bedtime, wake-up time, tiredness, sleepiness, and optimal subjective sleep duration. METHODS: Circadian preferences and sleep were investigated in 555 (Females N=247) Finnish students aged 15-20. The self-report measures included a shortened version of the Horne-Östberg Morningness-Eveningness Scale, the Epworth Sleepiness Scale as well as items probing feelings of tiredness, optimal subjective sleep durations, and bedtime and wake-up time on the most recent day and a typical weekend. Data were collected from Tuesday to Thursday during an ordinary school week. RESULTS AND CONCLUSION: The most frequent chronotype was the intermediate type (54%), and compared to previous studies, the prevalence of evening-oriented individuals was high (37%), whereas only 9% of the participants were classified as morning oriented. No gender-specific or chronotype-specific differences in sleep durations were observed, but girls/women and evening-orientated individuals reported suffering more from sleepiness, compared to boys/men and more morning-typed participants, respectively. About 20% of the total sample indicated that their subjective need for sleep was not satisfied during the weekdays nor the weekend, indicating chronic sleep deprivation. Among girls/women and evening-oriented individuals, the subjective sleep need was greater for weekday nights.

Prospective associations between sedentary time, sleep duration and adiposity in adolescents.

OBJECTIVE: The objective of this study was to investigate whether objectively measured sedentary time and sleep duration are associated with changes in adiposity from mid- to late adolescence. METHODS: Students (n = 504, 42% boys) were recruited from schools in Cambridgeshire, UK. At baseline (mean age 15.0 ± 0.3 years), sedentary time was objectively measured by ≥3 days of combined heart rate and movement sensing. Concurrently, sleep duration was measured by combined sensing in conjunction with self-reported bed times. Fat mass index (FMI; kg/m(2)) was estimated at baseline and follow-up (17.5 ± 0.3 years) by anthropometry and bioelectrical impedance. FMI change (ΔFMI) was calculated by subtracting the baseline from follow-up values. Linear regression models adjusted for basic demographics, moderate-to-vigorous physical activity (MVPA), and depressive symptoms were used to investigate associations of sedentary time and sleep duration (mutually adjusted for one another) with ΔFMI. RESULTS: FMI increased by 0.5 and 0.6 kg/m(2) in boys and girls, respectively, but there was no association between sedentary time and ΔFMI in either gender (p ≥ 0.087), and no association between sleep duration and ΔFMI in girls (p ≥ 0.61). In boys, each additional hour of baseline sleep significantly reduced the ΔFMI by 0.13 kg/m(2) (p = 0.049), but there was little evidence for this association after adjusting for MVPA and depressive symptoms (p = 0.15). CONCLUSIONS: Sedentary time may not determine changes in adiposity from mid- to late adolescence, nor may sleep duration in girls. However, sleep length may be inversely associated with adiposity gain in boys, depending on whether the relationship is confounded or mediated by MVPA and depression.