Metabolic, endocrine, and immune consequences of sleep deprivation

Sleep, sedentary behavior, and physical activity in Brazilian adolescents: Achievement recommendations and BMI associations through compositional data analysis

Physical activity, sedentary behavior (SB), and sleep are habitual human behaviors (HHB) which are modifiable throughout the different life phases. Therefore, it is necessary to analyze how the time distribution throughout the day among HHB may be associated with body mass index (BMI). These results could provide inferences which can guide interventions that trigger changes in adolescent behaviors in favor of their health. The objective of this study was to verify the proportion of adolescents who meet the recommendation of sleep, moderate to vigorous physical activity (MVPA), and screen time (ST); to analyze the associations between HHB and BMI, and to determine possible changes in BMI associated with time reallocation between different HHB. Daily HHB recommendations (yes/no) were analyzed by frequency distribution. Compositional data analyses were used to examine the association between HHB and the BMI z-score (zBMI) with covariates (sex, age, and socioeconomic status). Compositional isotemporal substitution models estimated the change in zBMI associated with HHB reallocations from 15 to 120 minutes. A total of 185 adolescents were included (15 to 18 years, 50.8% boys). Thus, total sleep time, SB, light physical activity (LPA) and MVPA were measured by 24-hour accelerometry for seven consecutive days. ST, demographic characteristics, and socioeconomic status were assessed using a questionnaire. Sleep, MVPA, and ST recommendations were achieved by 32.97%, 8.10%, and 1.08% of the sample, respectively. No adolescent was able to achieve all of the daily recommendations. Age was significantly and positively associated with zBMI (p<0.001). Simply replacing 75, 90, and 120 minutes of MVPA by LPA led to an estimated significant increase in zBMI (95CI% z-value, 0.01 to 1.49). The HHB relocation estimates in 24h did not show positive effects on zBMI, nor did it increase the time engaged in MVPA, which may raise the hypothesis that other parameters related to obesity and their related interactions need to be better understood.

The Lifestyle Profile of Individuals with Cardiovascular and Endocrine Diseases in Cyprus: A Hierarchical, Classification Analysis

The study aims to explore the lifestyle profile of adult individuals with cardiovascular and endocrine diseases in Cyprus. Age and sex-specific analyses were applied. A representative sample of the general adult population was recruited during 2018–2019 using stratified sampling among the five government-controlled municipalities of the Republic of Cyprus. Data on Mediterranean diet adherence, quality of sleep, smoking status, physical activity, Body Mass Index, and the presence of cardiovascular and endocrine diseases were collected using a validated questionnaire. Diseases were classified according to the International Classification of Diseases, Tenth Revision (ICD-10). A total of 1140 men and women over 18 years old (range: 18–94) participated in the study. The prevalence of cardiovascular and endocrine diseases among the adult general population of Cyprus was 24.8% and 17.2%, respectively, with a higher prevalence of cardiovascular diseases in men, and a higher prevalence of endocrine diseases in women. Among individuals with cardiovascular disease, 23.3% were aged between 18–44 years old, while the corresponding percentage among endocrine disease individuals was 48%. The prevalence of smoking, physical activity, a low adherence to the Mediterranean diet, poor quality of sleep and obesity among the study population was 35.5%, 48.0%, 32.9%, 39.0% and 13.6%, respectively. Individuals with cardiovascular and endocrine diseases were characterized by poor quality of sleep, inadequate physical activity, and a higher BMI. This is the first study in Cyprus exploring the profile of individuals with cardiovascular and endocrine diseases in Cyprus. Health promotion and educational programs focusing on the importance of sleep quality, healthier dietary habits, physical activity, and lower BMIs among people with cardiovascular and endocrine diseases should be developed.

Circadian rhythms and cancers: the intrinsic links and therapeutic potentials

The circadian rhythm is an evolutionarily conserved time-keeping system that comprises a wide variety of processes including sleep-wake cycles, eating-fasting cycles, and activity-rest cycles, coordinating the behavior and physiology of all organs for whole-body homeostasis. Acute disruption of circadian rhythm may lead to transient discomfort, whereas long-term irregular circadian rhythm will result in the dysfunction of the organism, therefore increasing the risks of numerous diseases especially cancers. Indeed, both epidemiological and experimental evidence has demonstrated the intrinsic link between dysregulated circadian rhythm and cancer. Accordingly, a rapidly increasing understanding of the molecular mechanisms of circadian rhythms is opening new options for cancer therapy, possibly by modulating the circadian clock. In this review, we first describe the general regulators of circadian rhythms and their functions on cancer. In addition, we provide insights into the mechanisms underlying how several types of disruption of the circadian rhythm (including sleep-wake, eating-fasting, and activity-rest) can drive cancer progression, which may expand our understanding of cancer development from the clock perspective. Moreover, we also summarize the potential applications of modulating circadian rhythms for cancer treatment, which may provide an optional therapeutic strategy for cancer patients.

Social and environmental effects of the COVID-19 pandemic on children

OBJECTIVE

This study aimed to review the literature, summarizing the existing evidence on the effects of the pandemic on children, adolescents and parents, with an emphasis on the psychological, emotional, and sleep quality consequences.

SOURCE OF DATA

Empirical studies identified in the following databases: MEDLINE, ISI Web of Knowledge/Web of Science, and preprint servers.

SYNTHESIS OF DATA

The findings point to a wide range of consequences for children and adolescents resulting from the COVID-19 pandemic, which mainly includes an increase in depressive mood symptoms. There is also an increase in anxiety symptoms, suicidal ideation, as well as potential delays in language and motor development resulting from deprivation of social interaction and the closing of schools. These effects are more severe due to previous neuropsychiatric conditions. For parents, there is an increase in anxiety, depressive and post-traumatic symptoms, which are more accentuated in those who suffered socioeconomic damage due to the pandemic. There was an important increase in situations of violence towards children by parents and caregivers during the pandemic. Also, changes in routine and fear of the pandemic have negatively impacted sleep quality, globally.

CONCLUSIONS

It is noteworthy that most studies published to date used a cross-sectional design and applied online screening questionnaires. The few studies with a longitudinal design suggest that these changes may have been transitory and more prevalent at the beginning of the pandemic.

Sleep quality in people with type 2 diabetes controlled at the primary level and its association with sociodemographic and clinical characteristics

Type 2 diabetes (DM2) is one of the diseases that cause the highest premature mortality and disability worldwide. Sleep disturbances have been associated with the onset of metabolic disorders and increased levels of glycated haemoglobin in diabetics.

OBJECTIVE

To evaluate the quality of sleep of people with type 2 diabetes and its association with sociodemographic, clinical, and metabolic characteristics.

METHODS

Observational, cross-sectional, analytical study of 223 patients with DM2 between 20 and 64 years old, controlled in a primary health care centre in Chile.

RESULTS

Most were women (66.4%), average age 54.7 years. Only 33% slept the required number of hours (7-9 h) to maintain health. Fifty-seven point seven percent were metabolically unbalanced (Hb1Ac > 7%). Seventy-five point two percent presented sleep problems of varying severity, which were associated with being a woman, night pain, nocturia, time of diagnosis of diabetes, and depressive symptoms. Persons with poor sleep quality were 73% more likely to be metabolically decompensated, however, this result was not statistically significant: OR = 1.73 (CI: 78-3.87).

CONCLUSIONS

The high frequency of poor sleep quality and metabolic decompensation in the sample stands out, which could complicate DM2. The association between poor sleep quality and DM2 decompensation is inconclusive. Future research will contribute to elucidating the role of sleep in metabolic compensation and in the prevention of metabolic disorders.

Role of sleep deprivation in immune-related disease risk and outcomes

Modern societies are experiencing an increasing trend of reduced sleep duration, with nocturnal sleeping time below the recommended ranges for health. Epidemiological and laboratory studies have demonstrated detrimental effects of sleep deprivation on health. Sleep exerts an immune-supportive function, promoting host defense against infection and inflammatory insults. Sleep deprivation has been associated with alterations of innate and adaptive immune parameters, leading to a chronic inflammatory state and an increased risk for infectious/inflammatory pathologies, including cardiometabolic, neoplastic, autoimmune and neurodegenerative diseases. Here, we review recent advancements on the immune responses to sleep deprivation as evidenced by experimental and epidemiological studies, the pathophysiology, and the role for the sleep deprivation-induced immune changes in increasing the risk for chronic diseases. Gaps in knowledge and methodological pitfalls still remain. Further understanding of the causal relationship between sleep deprivation and immune deregulation would help to identify individuals at risk for disease and to prevent adverse health outcomes.

Quality of Sleep in the Cypriot Population and Its Association With Multimorbidity: A Cross-Sectional Study

Poor sleep is a relatively common condition with possibly serious adverse health consequences. Lack of sleep affects the endocrine, immune, and nervous systems. In Cyprus, there is no information about the quality of sleep in the population. The goal of this study was to assess the quality of sleep in the Cypriot population and evaluate its association with multimorbidity. A representative sample of the adult population of Cyprus was selected in 2018-2019 among the five government-controlled municipalities of the Republic of Cyprus using stratified sampling. Data on sleep quality as well as on the presence of chronic, clinical, and mental health conditions were collected using a validated questionnaire. Diseases were classified according to the International Classification of Diseases, 10th Revision (ICD-10). A total of 1,140 Cypriot men and women over 18-years of age (range: 18-94) participated in the study. The median Pittsburgh sleep quality index score of the participants was 5 (first quartile = 3, third quartile = 7) with the maximum score being 17, which suggests that the Cypriot population has a relatively good quality of sleep overall, although, almost one-third of the study population had a poor quality of sleep. Women, residents of Paphos, and married people had a poorer quality of sleep (p < 0.05). Having a poor quality of sleep was associated with higher odds of multimorbidity (OR = 2.21, 95% CI: 1.55, 3.16), even after adjusting for demographics, socioeconomic, and lifestyle factors. Adopting good sleep habits could be beneficial and would potentially help reduce the risk of multimorbidity. Public health guidelines regarding the importance of sleep and its association with multimorbidity should be considered.

Does Modern Lifestyle Favor Neuroimmunometabolic Changes? A Path to Obesity

Factors linked to modern lifestyles, such as physical inactivity, Western diet, and poor sleep quality have been identified as key contributors to the positive energy balance (PEB). PEB rises adipose tissue hypertrophy and dysfunction over the years, affecting cells and tissues that are metabolically critical for energy homeostasis regulation, especially skeletal muscle, hypothalamic-pituitary-adrenal axis, and gut microbiota. It is known that the interaction among lifestyle factors and tissue metabolic dysfunction increases low-grade chronic systemic inflammation, leading to insulin resistance and other adverse metabolic disorders. Although immunometabolic mechanisms are widely discussed in obesity, neuroimmunoendocrine pathways have gained notoriety, as a link to neuroinflammation and central nervous system disorders. Hypothalamic inflammation has been associated with food intake dysregulation, which comprises homeostatic and non-homeostatic mechanisms, promoting eating behavior changes related to the obesity prevalence. The purpose of this review is to provide an updated and integrated perspective on the effects of Western diet, sleep debt, and physical exercise on the regulation of energy homeostasis and low-grade chronic systemic inflammation. Subsequently, we discuss the intersection between systemic inflammation and neuroinflammation and how it can contribute to energy imbalance, favoring obesity. Finally, we propose a model of interactions between systemic inflammation and neuroinflammation, providing new insights into preventive and therapeutic targets for obesity.

Some Twist of Molecular Circuitry Fast Forwards Overnight Sleep Hours: A Systematic Review of Natural Short Sleepers' Genes

This systematic review focuses on different genetic mutations identified in studies on natural short sleepers, who would not be ill-defined as one type of sleep-related disorder. The reviewed literature is from databases such as PubMed, PMC, Scopus, and ResearchGate. Due to the rare prevalence, the number of studies conducted on natural short sleepers is limited. Hence, searching the search of databases was done without any date restriction and included animal studies, since mouse and fly models share similarities with human sleep behaviors. Of the 12 articles analyzed, four conducted two types of studies, animal and human (cross-sectional or randomized-controlled studies), to testify the effects of human mutant genes in familial natural short sleepers via transgenic mouse or fly models. The remaining eight articles mainly focused on one type of study each: animal study (four articles), cross-sectional study (two articles), review (one article), and case report (one article). Hence, those articles brought different perspectives on the natural short sleep phenomenon by identifying intrinsic factors like DEC2, NPSR1, mGluR1, and β1-AR mutant genes. Natural short sleep traits in either point-mutations or single null mutations in those genes have been examined and confirmed its intrinsic nature in affected individuals without any related health concerns. Finally, this review added a potential limitation in these studies, mainly highlighting intrinsic causes since one case study reported an extrinsically triggered short sleep behavior in an older man without any family history. The overall result of the review study suggests that the molecular mechanisms tuned by identified sleep genes can give some potential points of therapeutic intervention in future studies.

Sleep Disturbances, Obesity, and Cognitive Function in Childhood: A Mediation Analysis

BACKGROUND

Childhood cognitive development is influenced by biological and environmental factors. One such factor, obesity, impairs cognitive development and is associated with sleep disturbances.

OBJECTIVES

We aimed to examine the mediating role of sleep disturbances on the relation between BMI and cognitive function in children.

METHODS

A total of 9951 children aged 9-10 y were included in this cross-sectional study. Children were recruited from the longitudinal ABCD (Adolescent Brain Cognitive Development) Study. Cognitive development was assessed using metrics for fluid, crystallized, and total cognitive function. Mediation analyses were conducted via linear regression modeling, with adjustment for potential confounders (sex, age, ethnicity, household income, parental education, and self-reported physical activity) for each of the 3 outcomes. Mediation significance was determined by bootstrapping.

RESULTS

A statistically significant inverse association was found between BMI and total (β = -0.41, P < 0.001) and fluid (β = -0.49, P < 0.001) cognition, but not for crystallized cognition. Total sleep disturbances partially mediated the association between BMI and fluid cognition (indirect effect: -0.02, P = 0.002; proportion of the total effect: 0.05, P = 0.002), but no mediation was found in the association between BMI and total cognition.

CONCLUSIONS

Sleep disturbances partially mediate the effect of childhood obesity on cognitive function, particularly in fluid cognitions. Future work is necessary to understand the effects of sleep disturbances and obesity on reduced childhood cognition throughout time, predominantly across the life course.

Sleep difficulties and related behavioral problems in Korean preschool children

OBJECTIVES

Sleep difficulties are associated with various behavioral problems and cognitive development, but the association has not been thoroughly evaluated in preschoolers with and without developmental disability (DD). The aim of this study was to compare the behavioral and cognitive characteristics of poor and good sleepers with and without DD in a community-based sample of preschool children.

METHODS

We recruited 196 children aged 34-77 months from community-based daycare centers, kindergartens, and special education centers. Children were classified as poor sleepers with DD (n = 23), poor sleepers without DD (n = 23), good sleepers with DD (n = 64), and good sleepers without DD (n = 94). Poor sleepers were defined based on Children's Sleep Habits Questionnaire Total Sleep Disturbance Score (CSHQ TSDS) cutoff of >52.

RESULTS

When compared to good sleepers with DD, poor sleepers with DD scored significantly higher on the Attention Problems (p = 0.005) and Aggressive Behaviors (p = 0.001) subscales of the CBCL, indicating greater difficulty. Caregivers of the poor sleepers with DD reported more depressive symptoms (p = 0.028) and more stress related to the child (p = 0.002) and the parent (p = 0.045) than caregivers of the good sleepers with DD. On the other hand, when compared to good sleepers without DD, poor sleepers without DD scored significantly higher only on the Anxious/Depressed subscale (p = 0.045) of the CBCL. Cognitive development and adaptive functioning were not significantly different between poor and good sleepers with and without DD. Among the subscales of the CSHQ, the Sleep Onset Delay showed strongest correlation with behavioral measures of the children and distress of the caregivers.

CONCLUSION

Externalizing problems such as aggressive behaviors, rather than cognitive development, are associated with sleep difficulties in preschool children with DD.

Self-reported poor quality of sleep in solid organ transplant: A systematic review

BACKGROUND

High quality sleep of sufficient duration is vital to overall health and wellbeing. Self-reported poor quality of sleep, sleep reported as irregular in timing, marked by frequent awakenings, or shortened in duration, is common across the solid-organ transplant trajectory.

AIM

This Systematic Review aimed to summarize available literature on rates of self-reported poor quality of sleep among solid organ transplant candidates and recipients.

METHODS

A systematic search of published literature was conducted in PubMed/MEDLINE, Embase, Web of Science, CINHAL, and PsychInfo databases with no date restrictions. Original articles in the English language describing self-reported quality of sleep using standardized questionnaires in adults either waitlisted for, or who received a solid organ transplant (heart, lung, kidney, liver, pancreas, or multi-solid organ) were included.

RESULTS

Of a potential 2054 articles identified, 44 were included (63.6% renal transplant, 20.5% liver transplant, 11.4% lung transplant, and 4.5% included multiple organ transplant populations), with the majority (68.2%) focusing only on post-transplant populations. No included articles focused solely on heart or pancreas transplant populations. On average, the transplant population with the greatest improvement in quality of sleep (reported as poor sleep quality, insomnia, sleep disturbance, or sleep dissatisfaction) from transplant candidacy to post-transplantation were renal transplant (from 53.5% pre, to 38.9% post) followed by liver transplant patients (from 52.8% pre, to 46.3% post), while lung transplant patients remained similar pre- to post-transplantation (55.6% pre, to 52% post). Poor quality of sleep was frequently associated with anxiety and depression, poorer quality of life, restless legs syndrome, and higher comorbidity.

CONCLUSIONS

Reports of poor quality of sleep are highly prevalent across all solid-organ transplant populations, both pre- and post-transplantation. Future studies should assess quality of sleep longitudinally throughout all phases of the transplantation trajectory, with more research focusing on how to optimize sleep in solid organ transplant populations.

Bidirectional associations between sedentary time and sleep duration among 12- to 14-year-old adolescents

Background

The aim of this study was to investigate bidirectional associations between (prolonged) sitting time and sleep duration in 12- to 14-year-old adolescents using a between-subjects and within-subjects analyses approach.

Methods

Observational data were used from 108 adolescents (53% girls; mean age 12.9 (SD 0.7) years) from six schools in Flanders, Belgium. The Axivity AX3 triaxial accelerometer, worn on the thigh, was used to assess daily total sitting time and daily time spent in sedentary bouts of ≥30 min (as a proxy for prolonged sitting time). The Fitbit Charge 3 was used to assess nightly sleep duration. Both monitors were worn on schooldays only (ranging from 4 to 5 days). Linear mixed models were conducted to analyse the associations, resulting in four models. In each model, the independent variable (sleep duration, sitting time or prolonged sitting time) was included as within- as well as between-subjects factor.

Results

Within-subjects analyses showed that when the adolescents sat more and when the adolescents spent more time sitting in bouts of ≥30 min than they usually did on a given day, they slept less during the following night (p = 0.01 and p = 0.05 (borderline significant), respectively). These associations were not significant in the other direction. Between-subjects analyses showed that adolescents who slept more on average, spent less time sitting (p = 0.006) and less time sitting in bouts of ≥30 min (p = 0.004) compared with adolescents who slept less on average. Conversely, adolescents who spent more time sitting on average and adolescents who spent more time sitting in bouts of ≥30 min on average, slept less (p = 0.02 and p = 0.003, respectively).

Conclusions

Based on the between-subjects analyses, interventions focusing on reducing or regularly breaking up sitting time could improve adolescents’ sleep duration on a population level, and vice versa. However, the within-subjects association was only found in one direction and suggests that to sleep sufficiently during the night, adolescents might limit and regularly break up their sitting time the preceding day.

Trial registration

Data have been used from our trial registered at ClinicalTrials.gov (NCT04327414; registered on March 11, 2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11694-9.

Effect of Aquatic Exercise on Sleep Efficiency of Adults With Chronic Musculoskeletal Pain

BACKGROUND

Aerobic exercise improves sleep for people who have difficulty in sleeping soundly, but most research to date has focused on land-based exercise. There has been only very limited research into the effect of aquatic exercise on people with chronic musculoskeletal (MSK) pain. The purpose of this study is to examine the effect of a 6-week aquatic exercise program on sleep efficiency among adults with chronic MSK pain.

METHODS

A total of 30 adults with chronic MSK pain were recruited by convenience sampling and assigned into intervention and control groups by a trained research assistant. Their sleep efficiency, sleep quality, activity level, stress level, and pain level were measured with ActiGraph GT3X accelerometer before and after the intervention group completed a 6-week, biweekly program of aquatic exercise.

RESULTS

Following intervention, the intervention group had significantly longer total true sleep time (by 27.6 min, P = .006); greater sleep efficiency (+3.01%, P = .005); and less pain (-1.33/10, P = .026). The control group had significantly shorter total true sleep time by 5.8 minutes (P = .036) while changes in the other outcomes were not significant.

CONCLUSIONS

Six weeks of moderate-intensity aquatic exercise may improve sleep efficiency and reduce pain for persons suffering chronic MSK pain.

Sleep quality among undergraduate students of a medical college in Nepal during COVID-19 pandemic: an online survey

Background Good sleep quality is associated with a diverse range of positive outcomes such as better health, less daytime sleepiness, well-being and proper psychological functioning. Sleep deprivation or poor sleep quality leads to many metabolic, endocrine, and immune changes. Many studies have shown changes in sleep schedule along with worsening of sleep quality during the COVID-19 pandemic. Methods This cross-sectional study was conducted among students of a medical college in Kathmandu, Nepal from January 13, 2021 to February 15, 2021. A stratified random sampling technique was used. Data were collected using the Pittsburgh Sleep Quality Index (PSQI). Questionnaires that were completely filled were included and analyzed using STATA vs. 15. Results 168(n=190) medical students filled out the questionnaires with a response rate of 88.42%. Around 30% (n=51) of respondents had poor sleep quality (PSQI total score of > 5) with an average PSQI score of 4.24±2.19. Unadjusted logistic regression analysis showed significantly higher odds of poor sleep quality among females (OR, 2.25; CI, 1.14-4.43) compared with male and the relation persists even after adjusting with age and year in medical school (aOR, 2.81; CI, 1.35-5.86).  Adjusting with age and gender, 4 th-year MBBS students had 82% lesser odds of having poor sleep quality compared to 2 nd-year MBBS students (aOR, 0.18; CI, 0.04-0.76). Our study is suggestive of poor sleep quality common among medical students. Conclusions More than a quarter of medical students have a poor sleep quality as per our study. So, education and awareness should be raised among medical students regarding the detrimental effects of poor quality sleep on daily activities, physical and mental well-being, and the overall quality of life.

Sleep quality among undergraduate students of a medical college in Nepal during COVID-19 pandemic: an online survey

Background

Good sleep quality is associated with a diverse range of positive outcomes such as better health, less daytime sleepiness, well-being and proper psychological functioning. Sleep deprivation or poor sleep quality leads to many metabolic, endocrine, and immune changes. Many studies have shown changes in sleep schedule along with worsening of sleep quality during the COVID-19 pandemic.

Methods

This cross-sectional study was conducted among students of a medical college in Kathmandu, Nepal from January 13, 2021 to February 15, 2021. A stratified random sampling technique was used. Data were collected using the Pittsburgh Sleep Quality Index (PSQI). Questionnaires that were completely filled were included and analyzed using STATA vs. 15.

Results

168(n=190) medical students filled out the questionnaires with a response rate of 88.42%. Around 30% (n=51) of respondents had poor sleep quality (PSQI total score of > 5) with an average PSQI score of 4.24±2.19. Unadjusted logistic regression analysis showed significantly higher odds of poor sleep quality among females (OR, 2.25; CI, 1.14-4.43) compared with male and the relation persists even after adjusting with age and year in medical school (aOR, 2.81; CI, 1.35-5.86).  Adjusting with age and gender, 4 ^th-year MBBS students had 82% lesser odds of having poor sleep quality compared to 2 ^nd-year MBBS students (aOR, 0.18; CI, 0.04-0.76). Our study is suggestive of poor sleep quality common among medical students.

Conclusions

More than a quarter of medical students have a poor sleep quality as per our study. So, education and awareness should be raised among medical students regarding the detrimental effects of poor quality sleep on daily activities, physical and mental well-being, and the overall quality of life.

Are periodontal diseases associated with sleep duration or sleep quality? A systematic review

OBJECTIVES

This study aimed to systematically review the associations between periodontal diseases/tooth loss and sleep duration/quality.

MATERIAL AND METHODS

PubMed, Scopus, and Embase databases were searched (up to May 2021) to identify studies that assessed the association between periodontal diseases or number of teeth with sleep quality and sleep duration. Two researchers independently selected the studies and extracted the data. Considering the high heterogeneity among the included studies, meta-analysis was deemed unviable. Results are presented descriptively for sleep quality (studies that have used PSQI), self-reported sleep hours, and other tools that assessed sleep patterns.

RESULTS

Twenty studies (16 cross-sectional, two case-control, and two cohort) were included. Eight studies used the Pittsburgh Sleep Quality Index (PSQI) to assess quality of sleep. Six of these studies demonstrated that individuals with worse periodontal conditions demonstrated poorer sleep quality. However, most of the included studies that performed adjusted analysis showed no statistically significant association between self-reported hours of sleep and periodontitis. The mean number of present teeth was assessed in four studies; three of them demonstrated lower numbers of present teeth in individuals with inadequate sleep.

CONCLUSION

The literature shows conflicting results for the association between sleep hours and periodontitis. However, inadequate sleep may be associated with lower number of present teeth and periodontal diseases. Further studies are necessary in order to confirm these results.

Differences in sleep measures and waking electroencephalography of patients with insomnia according to age and sex

STUDY OBJECTIVES

Sleep characteristics are known to be different according to age and sex. The objective of this study was to investigate differences in sleep parameters and quantitative electroencephalography of patients with insomnia according to age and sex.

METHODS

Patients with insomnia disorder ages 40-79 years were recruited. Each participant was assessed with the Pittsburgh Sleep Quality Index, 4-day wrist actigraphy, and quantitative electroencephalography derived from a 64-channel electroencephalogram system. These variables were compared between age groups (40-64 years vs 65-79 years) and sexes.

RESULTS

Among 173 participants, 61 (35%) were ages 65-79 years and 64 (35%) were males. The older group reported shorter (P = .009) total sleep time than the middle-aged group based on the Pittsburgh Sleep Quality Index, while women slept longer than men based on actigraphy (P = .040). Regarding electroencephalography, women had higher relative beta power than men (P = .006). Older patients showed slower dominant occipital frequency than younger patients (P = .008). The age effect was more noticeable on both clinical variables and quantitative electroencephalography for women. Compared with younger women, older women reported shorter total sleep time in the Pittsburgh Sleep Quality Index (P = .025), underestimated their sleep time (Pittsburgh Sleep Quality Index total sleep time/actigraphic total sleep time, P = .034), and showed reduced alpha power in the frontal area (P = .009).

CONCLUSIONS

Clinicians should be aware of the age and sex difference on manifestation of insomnia, which may further impact an individual's behaviors, such as staying in bed for a longer time or seeking sleep aids.

Association between sleep habits and symptoms of oral disease in adolescents: the 2017 Korea Youth Risk Behavior Web-based Survey

BACKGROUND

This cross-sectional study aimed to examine the relationship between sleep habits and oral disease symptoms in adolescents.

METHODS

Among 62,276 adolescents who participated in the 13th Korea Youth Risk Behavior Web-based Survey (2017), we selected a total of 54,766 adolescents (age, 12-18 years; male, 49.9%) for the final analysis, after excluding those who did not report their sleep duration. The 13th Korea Youth Risk Behavior Web-based Survey data were obtained from a stratified, multistage, clustered sample. Independent variables included general characteristics, oral health behavior, sleep types, sleep duration, and sleep quality; dependent variables comprised oral disease symptoms. Sleep was categorized according to bedtime astype A (bedtime < 1 a.m.) and type B (bedtime ≥ 1 a.m.). Data were analyzed using logistic regression analysis. Statistical significance was set at p < 0.05.

RESULTS

After adjusting for all covariates, adolescents with type A sleep had a higher risk of toothache on chewing (OR = 1.08, 95% CI 1.02-1.15) than adolescents with type B. Adolescents who slept for 6 h or less each night had a higher risk of pain in the tongue and buccal mucosa (OR = 1.35, 95% CI 1.18-1.54), gingival pain, and bleeding (OR = 1.31, 95% CI 1.19-1.45) than those who slept for more than 8 h. Adolescents with low quality of sleep had a higher risk of toothache or throbbing (OR = 1.70, 95% CI 1.60-1.81), toothache on chewing (OR = 1.73, 95% CI 1.65-1.82), and halitosis (OR = 1.51, 95% CI 1.41-1.59) than those with high quality of sleep.

CONCLUSIONS

Our findings indicate that some oral symptoms are related to sleep duration and quality. It is essential to inculcate good sleeping habits in adolescents by emphasizing the effects of inadequate sleep duration and quality.

Homeostatic state of microglia in a rat model of chronic sleep restriction

Chronic sleep restriction (CSR) negatively impacts brain functions. Whether microglia, the brain's resident immune cells, play any role is unknown. We studied microglia responses to CSR using a rat model featuring slowly rotating wheels (3 h on/1 h off), which was previously shown to induce both homeostatic and adaptive responses in sleep and attention. Adult male rats were sleep restricted for 27 or 99 h. Control rats were housed in locked wheels. After 27 and/or 99 h of CSR, the number of cells immunoreactive for the microglia marker ionized calcium-binding adaptor molecule-1 (Iba1) and the density of Iba1 immunoreactivity were increased in 4/10 brain regions involved in sleep/wake regulation and cognition, including the prelimbic cortex, central amygdala, perifornical lateral hypothalamic area, and dorsal raphe nucleus. CSR neither induced mitosis in microglia (assessed with bromodeoxyuridine) nor impaired blood-brain barrier permeability (assessed with Evans Blue). Microglia appeared ramified in all treatment groups and, when examined quantitatively in the prelimbic cortex, their morphology was not affected by CSR. After 27 h, but not 99 h, of CSR, mRNA levels of the anti-inflammatory cytokine interleukin-10 were increased in the frontal cortex. Pro-inflammatory cytokine mRNA levels (tumor necrosis factor-α, interleukin-1β, and interleukin-6) were unchanged. Furthermore, cortical microglia were not immunoreactive for several pro- and anti-inflammatory markers tested, but were immunoreactive for the purinergic P2Y12 receptor. These results suggest that microglia respond to CSR while remaining in a physiological state and may contribute to the previously reported homeostatic and adaptive responses to CSR.

Protocol for the Prognosticating Delirium Recovery Outcomes Using Wakefulness and Sleep Electroencephalography (P-DROWS-E) study: a prospective observational study of delirium in elderly cardiac surgical patients

INTRODUCTION

Delirium is a potentially preventable disorder characterised by acute disturbances in attention and cognition with fluctuating severity. Postoperative delirium is associated with prolonged intensive care unit and hospital stay, cognitive decline and mortality. The development of biomarkers for tracking delirium could potentially aid in the early detection, mitigation and assessment of response to interventions. Because sleep disruption has been posited as a contributor to the development of this syndrome, expression of abnormal electroencephalography (EEG) patterns during sleep and wakefulness may be informative. Here we hypothesise that abnormal EEG patterns of sleep and wakefulness may serve as predictive and diagnostic markers for postoperative delirium. Such abnormal EEG patterns would mechanistically link disrupted thalamocortical connectivity to this important clinical syndrome.

METHODS AND ANALYSIS

P-DROWS-E (Prognosticating Delirium Recovery Outcomes Using Wakefulness and Sleep Electroencephalography) is a 220-patient prospective observational study. Patient eligibility criteria include those who are English-speaking, age 60 years or older and undergoing elective cardiac surgery requiring cardiopulmonary bypass. EEG acquisition will occur 1-2 nights preoperatively, intraoperatively, and up to 7 days postoperatively. Concurrent with EEG recordings, two times per day postoperative Confusion Assessment Method (CAM) evaluations will quantify the presence and severity of delirium. EEG slow wave activity, sleep spindle density and peak frequency of the posterior dominant rhythm will be quantified. Linear mixed-effects models will be used to evaluate the relationships between delirium severity/duration and EEG measures as a function of time.

ETHICS AND DISSEMINATION

P-DROWS-E is approved by the ethics board at Washington University in St. Louis. Recruitment began in October 2018. Dissemination plans include presentations at scientific conferences, scientific publications and mass media.

TRIAL REGISTRATION NUMBER

NCT03291626.

Impact of road traffic noise on obesity measures: Observational study of three European cohorts

BACKGROUND

Environmental stressors such as transport noise may contribute to development of obesity through increased levels of stress hormones, sleep deprivation and endocrine disruption. Epidemiological evidence supporting an association of road traffic noise with obesity markers is still relatively scant and confined to certain geographical regions. We aimed to examine the cross-sectional associations between road traffic noise and obesity markers in three large European cohorts involving nearly 500,000 individuals.

METHODS

Three population-based cohorts (UK Biobank, Lifelines, HUNT3) were established between 2006 and 2013 in the UK, the Netherlands and Norway respectively. For all three cohorts, residential 24-h road traffic noise (Lden) for 2009 was modelled from a standardised European noise assessment framework. Residential exposures to NO2 for 2007 and PM2.5 for 2010 were estimated from Europe-wide land use regression models. Obesity markers including body mass index and waist circumference were measured at recruitment. Obesity and central obesity status were subsequently derived. Regression models were fitted in each cohort, adjusting for a harmonised set of demographic and lifestyle covariates, with further adjustments for air pollution in the main model.

RESULTS

The main analyses included 412,934 participants of UK Biobank, 61,032 of Lifelines and 30,305 of HUNT3, with a mean age of 43-56 years and Lden ranging 42-89 dB(A) across cohorts. In UK Biobank, per 10 dB(A) higher of Lden: BMI was higher by 0.14kg/m2 (95%CI: 0.11-0.18), waist circumference higher by 0.27 cm (95%CI: 0.19-0.35), odds of obesity was 1.06 (95%CI: 1.04-1.08) and of central obesity was 1.05 (95%CI: 1.04-1.07). These associations were robust to most other sensitivity analyses but attenuated by further adjustment of PM2.5 or area-level socioeconomic status. Associations were more pronounced among women, those with low physical activity, higher household income or hearing impairment. In HUNT3, associations were observed for obesity or central obesity status among those exposed to Lden greater than 55 dB(A). In contrast, no or negative associations were observed in the Lifelines cohort.

CONCLUSIONS

This largest study to date providing mixed findings on impacts of long-term exposure to road traffic noise on obesity, which necessitates future analyses using longitudinal data to further investigate this potentially important epidemiological link.

Sleep Deprivation and Neurological Disorders

Sleep plays an important role in maintaining neuronal circuitry, signalling and helps maintain overall health and wellbeing. Sleep deprivation (SD) disturbs the circadian physiology and exerts a negative impact on brain and behavioural functions. SD impairs the cellular clearance of misfolded neurotoxin proteins like α-synuclein, amyloid-β, and tau which are involved in major neurodegenerative diseases like Alzheimer's disease and Parkinson's disease. In addition, SD is also shown to affect the glymphatic system, a glial-dependent metabolic waste clearance pathway, causing accumulation of misfolded faulty proteins in synaptic compartments resulting in cognitive decline. Also, SD affects the immunological and redox system resulting in neuroinflammation and oxidative stress. Hence, it is important to understand the molecular and biochemical alterations that are the causative factors leading to these pathophysiological effects on the neuronal system. This review is an attempt in this direction. It provides up-to-date information on the alterations in the key processes, pathways, and proteins that are negatively affected by SD and become reasons for neurological disorders over a prolonged period of time, if left unattended.

Determinants of sleep quality in college students: A literature review

PURPOSE

To review the various determinants of sleep quality among college students.

METHODS

The PubMed, Web of Science and Cochrane Library databases were searched with the search string "sleep quality" AND "college students" for articles published between January 2007 and October 2017. Articles were excluded if they (1) examined sleep quality as a risk factor for other outcomes or (2) involved inpatients or participants under medical care.

RESULTS

The 112 identified studies were classified into categories according to the investigated determinants and their effect on sleep quality. Physical activity and healthy social relations improved sleep quality, while caffeine intake, stress and irregular sleep-wake patterns decreased sleep quality. Less consistent results were reported regarding eating habits and sleep knowledge, while proper napping during the day might improve overall sleep quality.

CONCLUSIONS

College students are vulnerable to different risk factors for sleep quality. When designing interventions to improve sleep quality among college students, the main determinants need to be taken into consideration.

What types of insomnia relate to anxiety and depressive symptoms in late life?

Background

Symptoms of insomnia are associated with symptoms of depression and anxiety in older adults, yet less is known about the relation of specific forms of insomnia (i.e., onset, maintenance, and terminal insomnia) with these symptoms. This study explored how insomnia types related to symptoms of anxiety and depression in older adults. It was hypothesized that onset and maintenance insomnia would have stronger relations to anxiety and depressive symptoms than terminal insomnia.

Methods

One-hundred thirty-three older adults (mean age 69, age range 65–89) were recruited using Amazon's Mechanical Turk. Participants completed the Insomnia Severity Index, Geriatric Depression Scale-Short Form, and Geriatric Anxiety Inventory-Short Form.

Results

Regression analyses that controlled for the comorbidity between anxiety and depressive symptoms indicated that onset insomnia was the only independent predictor of anxiety symptoms, and maintenance insomnia was the only independent predictor of depressive symptoms, each of which had medium to large effect sizes.

Limitations

Our findings are limited by an online, primarily Caucasian, and non-clinical sample as well as the cross-sectional design of the study.

Conclusions

Our findings suggest that despite overlap between symptoms of depression and anxiety, insomnia may have different mechanisms of affecting each disorder. Thus, the type of insomnia is clinically relevant and should be assessed when symptoms of anxiety, depression, and/or sleep difficulties are reported.

Effect of diurnal intermittent fasting during Ramadan on ghrelin, leptin, melatonin, and cortisol levels among overweight and obese subjects: A prospective observational study

BACKGROUND

Levels of cortisol, melatonin, ghrelin, and leptin are highly correlated with circadian rhythmicity. The levels of these hormones are affected by sleep, feeding, and general behaviors, and fluctuate with light and dark cycles. During the fasting month of Ramadan, a shift to nighttime eating is expected to affect circadian rhythm hormones and, subsequently, the levels of melatonin, cortisol, ghrelin, and leptin. The present study aimed to examine the effect of diurnal intermittent fasting (DIF) during Ramadan on daytime levels of ghrelin, leptin, melatonin, and cortisol hormones in a group of overweight and obese subjects, and to determine how anthropometric, dietary, and lifestyle changes during the month of Ramadan correlate with these hormonal changes.

METHODS

Fifty-seven overweight and obese male (40) and female (17) subjects were enrolled in this study. Anthropometric measurements, dietary intake, sleep duration, and hormonal levels of serum ghrelin, leptin, melatonin, and salivary cortisol were assessed one week before the start of Ramadan fasting and after 28 days of fasting at fixed times of the day (11:00 am-1:00 pm).

RESULTS

At the end of Ramadan, serum levels of ghrelin, melatonin, and leptin significantly (P<0.001) decreased, while salivary cortisol did not change compared to the levels assessed in the pre-fasting state.

CONCLUSIONS

DIF during Ramadan significantly altered serum levels of ghrelin, melatonin, and serum leptin. Further, male sex and anthropometric variables were the most impacting factors on the tested four hormones. Further studies are needed to assess DIF's impact on the circadian rhythmicity of overweight and obese fasting people.

The Bidirectional Relationship Between Sleep and Inflammation Links Traumatic Brain Injury and Alzheimer's Disease

Traumatic brain injury (TBI) and Alzheimer's disease (AD) are diseases during which the fine-tuned autoregulation of the brain is lost. Despite the stark contrast in their causal mechanisms, both TBI and AD are conditions which elicit a neuroinflammatory response that is coupled with physical, cognitive, and affective symptoms. One commonly reported symptom in both TBI and AD patients is disturbed sleep. Sleep is regulated by circadian and homeostatic processes such that pathological inflammation may disrupt the chemical signaling required to maintain a healthy sleep profile. In this way, immune system activation can influence sleep physiology. Conversely, sleep disturbances can exacerbate symptoms or increase the risk of inflammatory/neurodegenerative diseases. Both TBI and AD are worsened by a chronic pro-inflammatory microenvironment which exacerbates symptoms and worsens clinical outcome. Herein, a positive feedback loop of chronic inflammation and sleep disturbances is initiated. In this review, the bidirectional relationship between sleep disturbances and inflammation is discussed, where chronic inflammation associated with TBI and AD can lead to sleep disturbances and exacerbated neuropathology. The role of microglia and cytokines in sleep disturbances associated with these diseases is highlighted. The proposed sleep and inflammation-mediated link between TBI and AD presents an opportunity for a multifaceted approach to clinical intervention.

Preventing Type 2 Diabetes Among Midlife Women: A Feasibility Study Comparing a Combined Sleep and Lifestyle Intervention With a Standard Lifestyle Intervention

PURPOSE

The purpose of this pilot study was to evaluate the feasibility, acceptability, and initial efficacy of adding a sleep extension intervention to a well-established diabetes prevention intervention among midlife women with short sleep duration at risk for type 2 diabetes.

METHODS

For this 2-group comparative design, 26 women with prediabetes or metabolic syndrome and sleep duration <7 hours were recruited from the community to participate in an 8-session diet and physical activity lifestyle intervention alone (L-alone) or L-alone plus a behavioral sleep intervention (L+Sleep). Body mass index (BMI), waist circumference, and other outcomes were compared at baseline and 3 and 6 months using analysis of covariance.

RESULTS

Incorporating a sleep intervention into lifestyle changes proved feasible and acceptable to midlife women at risk for type 2 diabetes. Significant decreases in BMI and waist circumference over time were observed in both groups, but comparative efficacy of L+Sleep versus L-alone yielded few group differences. Exploratory analysis indicated that women who increased their sleep to ≥7 h/night, regardless of group assignment, lost more weight than women who continued to report sleeping <7 h/night.

CONCLUSION

Adding sleep extension to a lifestyle change intervention proved feasible and satisfactory to participants, but initial efficacy did not differentiate the 2 intervention groups.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Ramadan intermittent fasting and immunity: An important topic in the era of COVID-19

WITH the growing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome (SARS)-related coronavirus (SARS-CoV-2) infection, a parallel growing interest arose concerning potential preventive and adjunct therapies, dietary and lifestyle modifications, and remedies that may boost the immunity against SARS-CoV-2 infection. Furthermore, as Ramadan intermittent religious fasting that is practiced by about one and a half billion Muslims throughout the globe is coincide this year with COVID-19 pandemic, a growing debate rose concerning the expected impact of fasting during Ramadan month and the associated dietary and lifestyle behaviors on the body's immunity against the pandemic infection. Published literature was searched to find out how intermittent fasting (IF) and its model of Ramadan affect the various aspects related to the body's immunity against microbial infections. IF was found to impact immunity by changing different related elements, including oxidative stress and inflammation, metabolism, body weight, and body composition. Dietary and lifestyle modifications during Ramadan month and their impact on immunity, such as water intake and hydration status, sleep duration and timing, caloric intake and mealtime, and social and spirtual activities, were addressed. Further research is warranted to figure out how IF during ramadan affects immunity against SARS-CoV-2 infection.

The protective effect of alpha lipoic acid (ALA) on social interaction memory, but not passive avoidance in sleep-deprived rats

Sleep is involved in maintaining energy, regulating heat, and recovering tissues. Furthermore, proper cognitive functions need sufficient sleep. Many studies have revealed the impairment effect of sleep deprivation (SD) on cognitive functions including learning and memory. Alpha lipoic acid (ALA) is a potent free radical scavenger, biological antioxidant, and neuroprotective agent. Furthermore, ALA improves learning and memory performance, decreases oxidative stress, and enhances antioxidant biomarkers. In this study, we aimed to investigate the effect of ALA on social interaction and passive avoidance memories in sleep-deprived rats. Total sleep deprivation (TSD) apparatus was used to induce SD (for 24 h). Three-chamber paradigm test and shuttle box apparatus were used to evaluate social interaction and passive avoidance memory, respectively. Rats' locomotor apparatus was used to assess locomotion. ALA was administered intraperitoneally at doses of 17 and 35 mg/kg for 3 consecutive days. The results showed SD impaired both types of memories. ALA at the dose of 35 mg/kg restored social interaction memory in sleep-deprived rats; while, at the dose of 17 mg/kg attenuated impairment effect of SD. Moreover, ALA at the dose of 35 mg/kg impaired passive avoidance memory in sham-SD rats and at both doses did not rescue passive avoidance memory in sleep-deprived rats. In conclusion, ALA showed impairment effect on passive avoidance memory, while improved social interaction memory in sleep-deprived rats.

The association of stress with sleep quality among medical students at King Abdulaziz University

OBJECTIVE

This study aims to determine the prevalence and the association of stress with sleep quality among medical students at King Abdulaziz University (KAU), Jeddah, Saudi Arabia.

METHODS

A cross-sectional study was done among 326 medical students of KAU using a stratified random sampling technique. An electronic self-administered questionnaire was used. Kessler Psychological Distress Scale (K10) and Pittsburgh Sleep Quality Index (PSQI) were used to assess the stress and sleep quality, respectively.

RESULTS

The overall students who experienced stress were 65%. The prevalence of poor sleep quality (total PSQI score ≥5) was 76.4%. There was a strong association between stress and poor sleep quality (value of Cramer's V = 0.371, P < 0.001), and it showed that the increase in stress level is a significant predictor of poor sleep quality.

CONCLUSION

A high prevalence of stress and poor sleep quality was found among the students and the study confirms a strong association between them. We recommend establishing courses focusing on educating the students about proper sleep hygiene and how to deal with the stressful environment.

Short-term sleep deprivation in mice induces B cell migration to the brain compartment

Increasing evidence highlight the involvement of immune cells in brain activity and its dysfunction. The brain's immune compartment is a dynamic ensemble of cells that can fluctuate even in naive animals. However, the dynamics and factors that can affect the composition of immune cells in the naive brain are largely unknown. Here, we examined whether acute sleep deprivation can affect the brain's immune compartment (parenchyma, meninges, and choroid plexus). Using high-dimensional mass cytometry analysis, we broadly characterized the effects of short-term sleep deprivation on the immune composition in the mouse brain. We found that after 6 h of sleep deprivation, there was a significant increase in the abundance of B cells in the brain compartment. This effect can be accounted for, at least in part, by the elevated expression of the migration-related receptor, CXCR5, on B cells and its ligand, cxcl13, in the meninges following sleep deprivation. Thus, our study reveals that short-term sleep deprivation affects the brain's immune compartment, offering a new insight into how sleep disorders can affect brain function and potentially contribute to neurodegeneration and neuroinflammation.

The relationship between sleep quality, stress, and academic performance among medical students

BACKGROUND:

Sleep is essential for the body, mind, memory, and learning. However, the relationship between sleep quality, stress, and academic performance has not been sufficiently addressed in the literature. The aim of this study was to assess the quality of sleep and psychological stress among medical students and investigate the relationship between sleep quality, stress, and academic performance.

MATERIALS AND METHODS:

This cross-sectional study targeted all medical students in their preclinical years at a Saudi medical college in 2019. All students were asked to complete an electronic self-administered questionnaire comprising the Pittsburgh Sleep Quality Index (PSQI), the Kessler Psychological Distress Scale (K10), questions on the students' current overall grade point average, and other demographic and lifestyle factors. The associations between categorical variables were analyzed using Pearson's Chi-squared test at 0.05 significance level.

RESULTS:

The mean PSQI score was 8.13 ± 3.46; 77% of the participants reported poor quality of sleep and 63.5% reported some level of psychological stress (mean K10 score: 23.72 ± 8.55). Poor quality of sleep was significantly associated with elevated mental stress levels (P < 0.001) and daytime naps (P = 0.035). Stepwise logistic regression model showed that stress and daytime nap were associated with poor sleep quality. Whereas, poor sleep or stress did not show any significant association with academic performance.

CONCLUSION:

Poor sleep quality was significantly associated with elevated levels of strees. However, they did not show any statistically significant relationship with academic performance.

Sleep duration trajectories from age 3 to 48 months in The Pelotas (Brazil) 2004 Birth Cohort Study

BACKGROUND

Optimal sleep is essential for child growth, development, and immune function. Few studies have evaluated factors associated with sleep duration in childhood from a longitudinal perspective.

OBJECTIVES

This study aimed to identify trajectories of sleep duration in childhood and associated maternal and child characteristics.

METHODS

Sleep duration was assessed by maternal report at 3, 12, 24, and 48 months among children from the Pelotas (Brazil) 2004 Birth Cohort. Independent variables included family income, maternal and child demographics, and clinical characteristics. Trajectory analysis was carried out using a semi-parametric, group-based modelling approach. Multinomial logistic regression provided odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between independent variables and sleep duration trajectory groups.

RESULTS

A total of 3824 participants were included in the analyses. Three trajectories of sleep duration were identified: "short sleepers" (9.1%), "typical sleepers" (72.1%), and "initially longer sleepers" (18.8%). When compared to typical sleepers, children from less schooled mothers (OR 1.82, 95% CI 1.26, 2.62) and those whose mothers reported depressive symptoms during pregnancy (OR 1.31, 95% CI 1.02, 1.68) and consumed alcohol beverages at 3 months post-partum (OR 1.60, 95% CI 1.03, 2.50) were more likely to be short sleepers. Children who shared the bedroom with another child were about 40% (OR 1.41, 95% CI 1.07, 1.87) more likely to be short sleepers. None of the investigated maternal and child characteristics remained associated with the "initially longer sleeper" group.

CONCLUSIONS

Among the identified trajectories, the group with short sleep duration trajectory deserves special attention given the importance of adequate sleep duration in the first years of life for the child's growth and development and the high concomitance of other risk factors, such as less schooled mothers, and mothers who reported depressive symptoms during pregnancy and consumed alcohol at 3 months post-partum.

Association Between Sleep Quality and Physical Activity in Saudi Arabian University Students

BACKGROUND

Many studies have documented a strong association between poor sleep quality and physical inactivity. This study evaluates the association between poor sleep quality and physical inactivity among Jazan University students in Saudi Arabia.

METHODS

An observational cross-sectional study was conducted among undergraduate students at Jazan University. Cluster random sampling was used to select 440 students. The Pittsburgh Sleep Quality Index (PSQI), International Physical Activity Questionnaire (IPAQ), and Depression Anxiety Stress Scales (DASS) were utilized for data collection.

RESULTS

According to the PSQI results, the majority of respondents (63.9%; n = 281) reported having poor sleep quality. The majority of students (62.7%; n = 276) were also physically inactive. Based on DASS-21 criteria, the majority of students (53.4%) were stressed. Sleep quality differed significantly according to participants' physical activity status (p = 0.0090). Among physically active participants, 43.9% reported having good sleep quality. Sleep duration, daytime dysfunctions, and global PSQI differed significantly according to levels of physical activity (p < 0.05 for all). Univariate analysis revealed that being physically active was significantly associated with good sleep quality (OR = 1.70, 95% CI 1.14-2.54, p < 0.001). Multivariate logistic regression models also demonstrated a significant association between physical activity and good sleep quality (OR = 1.72, 95% CI 1.15-2.56, p = 0.008).

CONCLUSION

The majority of Jazan University students had poor sleep quality and were physically inactive. Evidence-based prevention and therapeutic strategies are needed to promote physical activity among university students.

Region-specific adenosinergic modulation of the slow-cortical rhythm in urethane-anesthetized rats

Slow cortical rhythm (SCR) is a rhythmic alternation of UP and DOWN states during sleep and anesthesia. SCR-associated slow waves reflect homeostatic sleep functions. Adenosine accumulating during prolonged wakefulness and sleep deprivation (SD) may play a role in the delta power increment during recovery sleep. NREM sleep is a local, use-dependent process of the brain. In the present study, direct effect of adenosine on UP and DOWN states was tested by topical application to frontal, somatosensory and visual cortices, respectively, in urethane-anesthetized rats. Local field potentials (LFPs) were recorded using an electrode array inserted close to the location of adenosine application. Multiple unit activity (MUA) was measured from layer V-VI in close proximity of the recording array. In the frontal and somatosensory cortex, adenosine modulated SCR with slow kinetics on the LFP level while MUA remained mostly unaffected. In the visual cortex, adenosine modulated SCR with fast kinetics. In each region, delta power increment was based on the increased frequency of state transitions as well as increased height of UP-state associated slow waves. These results show that adenosine may directly modulate SCR in a complex and region-specific manner which may be related to the finding that restorative processes may take place with varying duration and intensity during recovery sleep in different cortical regions. Adenosine may play a direct role in the increment of the slow wave power observed during local sleep, furthermore it may shape the region-specific characteristics of the phenomenon.

Association between sleep duration and hypertension of migrant workers in China: a national cross-sectional surveillance study

OBJECTIVES

To examine the relationship between sleep duration and hypertension of migrant workers aged 18-59 years in China.

DESIGN

Population-based cross-sectional study using a complex survey sampling design.

PARTICIPANTS

There were 43 655 subjects in our analysis, after excluding people with missing information for key exposure and outcome variables and abnormal values for sleep duration (≤2 or ≥17 hours).

PRIMARY OUTCOME MEASURE

Hypertension was defined as systolic blood pressure (BP) ≥140 mm Hg and/or diastolic BP ≥90 mm Hg, or self-reported history of hypertension diagnosis in hospitals at the township (community) level or above and use of hypertensive medicine in the last 2 weeks.

RESULTS

Of 43 655 subjects, 15.6% (95% CI 15.1% to 16.1%) of migrant workers had hypertension. The prevalence of hypertension decreased with the increased sleep duration, both in males and females. Logistic regression models, using 7-8 hours sleep/day as the reference, showed a greater odds for hypertension among men and women who reported <6 hours of sleep after adjusting for sociodemographic characteristics, behavioural risk factors, body mass index, diabetes, stroke and myocardial infarction (men: OR 1.26; 95% CI 1.03 to 1.54, women: OR 1.55; 95% CI 1.13 to 2.06, p_interaction=0.096). Further stratified by age and migration time, it revealed that among adults less than 45 years old, those sleeping 9 or more hours had adjusted odds for hypertension of 0.82 (95% CI 0.72 to 0.93, p_interaction=0.020),while there was no evidence of an association between sleep duration and hypertension among adults aged 45-59 years. Among adults whose migration time was less than 4.5 years, those sleeping 9 or more hours had adjusted odds for hypertension of 0.80 (95% CI 0.68 to 0.94, p_interaction=0.097).

CONCLUSION

The association between sleep duration and hypertension varies by age. Short sleep duration (<6 hours) is associated with an increased prevalence of hypertension in both genders.