The important role of sleep in metabolism

Sarcopenia risk, sarcopenia-related quality of life, and associated factors in people living with human immunodeficiency virus (HIV): A web-based survey

OBJECTIVES

We aimed to screen for the risk of sarcopenia and sarcopenia-related quality of life and associated factors of people living with HIV (PLWH).

RESEARCH METHODS AND PROCEDURES

This nonprobabilistic web-based survey evaluated PLWH. The participants were invited directly from a university-based inpatient clinic and responded to a web questionnaire that included the SARC-F and SarQoL to screen people at risk of sarcopenia and their quality of life. People at risk of sarcopenia were defined by the proposed cutoff points for SARC-F (≥ 4 points), and SarQoL overall score was categorized according to the median. Moreover, we performed a logistic regression to investigate associations between HIV-, lifestyle-, and health-associated factors (i.e., physical activity, dietary pattern, sleep quality, gastrointestinal symptoms, HIV diagnosis, type, combinations, and duration of ART, smoking, drinking, BMI, and weight loss), and outcomes (SARC-F and SarQoL).

RESULTS

The sample comprised 202 PLWH, mainly middle-aged (50.6-60.5 y; n = 101). Only 5.9% (n = 12) are at risk of sarcopenia according to SARC-F, and only 17.3% (n = 35) exhibited lower sarcopenia-related quality of life according to SarQoL. In the multiple models, only the gastrointestinal symptoms increased the odds of sarcopenia risk (OR: 1.058; P = 0.01) and poor sarcopenia-associated quality of life (OR: 1.041; P = 0.013).

CONCLUSIONS

We verified that only 5.9% and 17.3% of PLWH are at risk of sarcopenia and presented lower sarcopenia-related quality of life, respectively. Only the gastrointestinal symptoms were associated with a risk of sarcopenia and lower sarcopenia-related quality of life, without significant differences between age groups.

Use of melatonin in children and adolescents with idiopathic chronic insomnia: a systematic review, meta-analysis, and clinical recommendation

Background

Melatonin prescriptions for children and adolescents have increased substantially during the last decade. Existing clinical recommendations focus on melatonin as a treatment for insomnia related to neurodevelopmental disorders. To help guide clinical decision-making, we aimed to construct a recommendation on the use of melatonin in children and adolescents aged 5-20 years with idiopathic chronic insomnia.

Methods

A systematic search for guidelines, systematic reviews and randomised controlled trials (RCT) were performed in Medline, Embase, Cochrane Library, PsycInfo, Cinahl, Guidelines International Network, Trip Database, Canadian Agency for Drugs and Technologies in Health, American Academy of Sleep Medicine, European Sleep Research Society and Scandinavian Health Authorities databases. A search for adverse events in otherwise healthy children and adolescents was also performed. The latest search for guidelines, systematic reviews, and adverse events was performed on March 18, 2023. The latest search for RCTs was performed on to February 6, 2023. The language was restricted to English, Danish, Norwegian, and Swedish. Eligible participants were children and adolescents (5-20 years of age) with idiopathic chronic insomnia, in whom sleep hygiene practices have been inadequate and melatonin was tested. There were no restrictions on dosage, duration of treatment, time of consumption, or release formula. Primary outcomes were quality of sleep, daytime functioning and serious adverse events. Secondary outcomes included total sleep time, sleep latency, awakenings, drowsiness, quality of life, all-cause dropouts, and non-serious adverse events. Outcomes were assessed at different time points to assess short-term and long-term effects. Meta-analysis was performed using inverse variance random-effects model and risk of bias was assessed using Cochrane risk of bias tool. If possible, funnel plots would be constructed to investigate publication bias. Heterogeneity was calculated via I² statistics. A multidisciplinary guideline panel formulated the recommendation according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). The certainty of evidence was considered either high, moderate, low or very low depending on the extent of risk of bias, inconsistency, imprecision, indirectness, or publication bias. The evidence-to-decision framework was subsequently used to discuss the feasibility and acceptance of the constructed recommendation alongside the impact on resources and equity. The protocol is registered with the Danish Health Authority.

Findings

We included eight RCTs with 419 children and adolescents with idiopathic chronic insomnia. Melatonin led to a moderate increase in total sleep time by 30.33 min (95% confidence interval (CI) 18.96-41.70, 4 studies, I² = 0%) and a moderate reduction in sleep latency by 18.03 min (95% CI -26.61 to -9.44, 3 studies, I² = 0%), both as assessed by sleep diary. No other beneficial effects were found. None of the studies provided information on serious adverse events, yet the number of participants experiencing non-serious adverse events was increased (Relative risk 3.44, 95% CI 1.25-9.42, 4 studies, I² = 0%). Funnel plots were not constructed due to the low number of studies. The certainty of evidence was very low on the quality of sleep and low for daytime functioning.

Interpretation

Evidence of very low certainty shows that benefits are limited and unwanted events are likely when melatonin is used to treat otherwise healthy children and adolescents with chronic insomnia. Melatonin should never be the first choice of treatment for this particular population, yet carefully monitored short-term use may be considered if sleep hygiene practices and non-pharmacological interventions have proven inadequate, and only if daytime function is compromised.

Funding

The Danish Health Authority and the Parker Institute, Bispebjerg and Frederiksberg Hospital supported by the Oak Foundation.

Melatonin Treatment in Kidney Diseases

Melatonin is a neurohormone that is mainly secreted by the pineal gland. It coordinates the work of the superior biological clock and consequently affects many processes in the human body. Disorders of the waking and sleeping period result in nervous system imbalance and generate metabolic and endocrine derangements. The purpose of this review is to provide information regarding the potential benefits of melatonin use, particularly in kidney diseases. The impact on the cardiovascular system, diabetes, and homeostasis causes melatonin to be indirectly connected to kidney function and quality of life in people with chronic kidney disease. Moreover, there are numerous reports showing that melatonin plays a role as an antioxidant, free radical scavenger, and cytoprotective agent. This means that the supplementation of melatonin can be helpful in almost every type of kidney injury because inflammation, apoptosis, and oxidative stress occur, regardless of the mechanism. The administration of melatonin has a renoprotective effect and inhibits the progression of complications connected to renal failure. It is very important that exogenous melatonin supplementation is well tolerated and that the number of side effects caused by this type of treatment is low.

Adverse effects of inadequate sleep duration patterns during pregnancy on toddlers suspected developmental delay: A longitudinal study

BACKGROUND

Although studies have reported the effects of inadequate sleep on maternal health, few have examined the relationships of maternal sleep patterns with fetal health and early childhood development. This study investigated maternal sleep duration patterns from early pregnancy to 3-years postpartum and their effects on birth outcomes and child development.

METHODS

This study recruited pregnant women and their partners during prenatal visits at five selected hospitals in the Taipei area; follow-up lasted from July 2011 to April 2021. A total of 1178 parents completed self-reported assessments from early pregnancy until childbirth and 544 completed eight assessments up to 3-years postpartum. Generalized estimated equation models were used for analyses.

RESULTS

Group-based trajectory modeling was used to identify four trajectories of sleep duration patterns. Although maternal sleep duration was not associated with birth outcomes, maternal "short decreasing" and "stably short" sleep patterns were associated with a higher risk of suspected overall developmental delay and language developmental delay, respectively. Furthermore, an "extremely long decreasing" pattern was associated with a higher risk of suspected overall developmental delay, [adjusted odds ratio (aOR) = 2.97, 95% confidence interval (CI):1.39-6.36)], gross motor delay, (aOR = 3.14, 95% CI: 1.42-6.99) and language developmental delay (aOR = 4.59, 95% CI:1.62-13.00). The results were significant for the children of multiparous women.

CONCLUSIONS

We identified a U-shaped distribution of risk between offspring developmental delay and maternal prenatal sleep duration, with the highest risk levels on both ends of the maternal prenatal sleep duration pattern. Interventions for maternal sleep are relatively straightforward to implement and should thus be a key part of standard prenatal care.

Intake of ultra-processed foods and sleep-related outcomes: A systematic review and meta-analysis

The aim of this review article was to evaluate the association between the intake of ultra-processed foods and sleep-related outcomes through a systematic review and meta-analysis. Pubmed, LILACS, Scielo, Scopus, Embase, and Web of Science were searched on December 31, 2021, for studies that evaluated the association between ultra-processed foods and sleep-related outcomes (self-reported sleep duration and quality). Pooled odds ratios were assessed through a random-effects model; heterogeneity was evaluated using the I² statistic. Fifteen cross-sectional studies were included; 14 showed that the high intake of ultra-processed foods was statistically significantly associated with sleep-related outcomes (sleep duration and quality). In the crude analysis, compared with low intake, high intake of ultra-processed foods increased the odds of sleep-related outcomes, with increased odds among children and/or adolescents, and null results among adults. When adjusted for cofounders, we found statistically significant results for all ages. The high intake of ultra-processed foods was associated with sleep-related outcomes, with moderate credibility of the evidence. Longitudinal studies and clinical trials confirming these findings are necessary.

Sleep loss effects on physiological and cognitive responses to systemic environmental hypoxia

In the course of their missions or training, alpinists, but also mountain combat forces and mountain security services, professional miners, aircrew, aircraft and glider pilots and helicopter crews are regularly exposed to altitude without oxygen supplementation. At altitude, humans are exposed to systemic environmental hypoxia induced by the decrease in barometric pressure (<1,013 hPa) which decreases the inspired partial pressure of oxygen (PIO₂), while the oxygen fraction is constant (equal to approximately 20.9%). Effects of altitude on humans occur gradually and depend on the duration of exposure and the altitude level. From 1,500 m altitude (response threshold), several adaptive responses offset the effects of hypoxia, involving the respiratory and the cardiovascular systems, and the oxygen transport capacity of the blood. Fatigue and cognitive and sensory disorders are usually observed from 2,500 m (threshold of prolonged hypoxia). Above 3,500 m (the threshold for disorders), the effects are not completely compensated and maladaptive responses occur and individuals develop altitude headache or acute altitude illness [Acute Mountain Sickness (AMS)]. The magnitude of effects varies considerably between different physiological systems and exhibits significant inter-individual variability. In addition to comorbidities, the factors of vulnerability are still little known. They can be constitutive (genetic) or circumstantial (sleep deprivation, fatigue, speed of ascent.). In particular, sleep loss, a condition that is often encountered in real-life settings, could have an impact on the physiological and cognitive responses to hypoxia. In this review, we report the current state of knowledge on the impact of sleep loss on responses to environmental hypoxia in humans, with the aim of identifying possible consequences for AMS risk and cognition, as well as the value of behavioral and non-pharmacological countermeasures.

Clinical Spectrum and Trajectory of Innovative Therapeutic Interventions for Insomnia: A Perspective

Increasing incidences of insomnia in adults, as well as the aging population, have been reported for their negative impact on the quality of life. Insomnia episodes may be associated with neurocognitive, musculoskeletal, cardiovascular, gastrointestinal, renal, hepatic, and metabolic disorders. Epidemiological evidence also revealed the association of insomnia with oncologic and asthmatic complications, which has been indicated as bidirectional. Two therapeutic approaches including cognitive behavioral therapy (CBT) and drugs-based therapies are being practiced for a long time. However, the adverse events associated with drugs limit their wide and long-term application. Further, Traditional Chinese medicine, acupressure, and pulsed magnetic field therapy may also provide therapeutic relief. Notably, the recently introduced cryotherapy has been demonstrated as a potential candidate for insomnia which could reduce pain, by suppressing oxidative stress and inflammation. It seems that the synergistic therapeutic approach of cryotherapy and the above-mentioned approaches might offer promising prospects to further improve efficacy and safety. Considering these facts, this perspective presents a comprehensive summary of recent advances in pathological aetiologies of insomnia including COVID-19, and its therapeutic management with a greater emphasis on cryotherapy.

Short-term effect of physical activity on sleep health: A population-based study using accelerometry

BACKGROUND

Regular physical activity (PA) is an important behavior in improving sleep health. However, the short-term effects of PA on sleep are still controversial. This study aimed to verify the effect of different intensities of PA practiced in different periods of the day on the subsequent sleep night in a population-based cohort of young adults.

METHODS

Prospective analyses were conducted for PA performed during the day and its effect on the following sleep night using data from the 22-year follow-up of the 1993 Pelotas Birth Cohort in Brazil (mean age of participants = 22.6 years). Wrist-worn accelerometry was used to measure both PA and sleep parameters. Regarding intensity, we analyzed the sleep effect of light PA (LPA), moderate PA, and vigorous PA, stratified by sex. Sleep variables were sleep time window (STW; the difference between sleep onset and sleep end), total sleep time (TST; the sum of minutes classified as sleep in STW), and sleep percent (SP; SP = (TST/STW); expressed in percentage). We performed generalized estimating equations using Stata software.

RESULTS

The means of STW, TST, and SP were 443.6 min/day, 371.1 min/day, and 84%, respectively. Time spent in moderate PA and vigorous PA in the morning and afternoon was not associated with sleep variables. Among men, 10 min/day of morning LPA increased TST by 2.56 min/day. Among women, 10 min/day of morning LPA increased SP by 0.15 percentage points. Afternoon LPA also increased SP by 0.09 percentage points for women. Night PA seems to have an inverse effect on sleep variables for any intensity and both sexes.

CONCLUSION

The effect of PA on sleep health is intrinsically related to the period of the day in which it is performed. The effect magnitude is different between sexes. For better sleep health, it is preferable that PA be performed during the day.

Sleep characteristic profiles and the correlation with spectrum of metabolic syndrome among older adult: a cross-sectional study

Background

Metabolic Syndrome (MetS) is a common health problem among older adults. Previous studies have revealed the relationship between sleep duration as well as global sleep status and MetS.

Objectives

This study aims to examine the association between the specific sleep characteristic and MetS as well as MetS components among community-dwelling old adults.

Methods

This cross-sectional study included 1499 community residents aged ≥ 60 years. Sleep characteristics were assessed using the Pittsburgh Sleep Quality Index (PSQI) and bed/rise time of the residents. Logistic regression analysis and multiple linear regression analysis were used to examine the associations between sleep characteristics and MetS as well as MetS components. A generalized additive model was built to assess the smooth relationship between triglyceride (TG) levels and sleep duration.

Results

Of the 1499 participants, 449 (30.0%) had MetS, and 443 (29.6%) had poor sleep quality. The rise time was found to be associated with MetS (> 6:00 vs. 5:00 ~ 6:00: adjusted OR (95%) = 1.77 (1.17–2.69), P = 0.007). For the MetS components, a U-shaped relationship was first revealed for sleep duration and TG levels (EDF = 1.85, P < 0.001). Furthermore, significant associations also included the associations of subjective sleep quality and daytime dysfunction with hypertension, the associations of sleep efficiency and rise time with hyperglycemia, the associations of rise time with TG levels, and the association of bedtime with waist circumference.

Conclusions

The different sleep characteristics were associated with different MetS components.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03074-8.

Sleep pattern regularity and measures of infant weight and length during the first 6 months

PURPOSE

To examine the association between sleep pattern regularity and measures of weight and length in infants.

DESIGN AND METHODS

This was a prospective observational study conducted in a university-affiliated children's hospital in northern Taiwan. A total of 316 healthy infants recruited during their 6-month well-child checkups had their weight and recumbent length measured, and wore an actigraph on the ankle for a week. Based on average weekday, weekend, and all-week sleep durations, infants were categorized into 3 groups: regular sleep, weekend catch-up sleep, and weekend sleep curtailment. General linear model analyses were performed with the 3 sleep regularity groups as the primary predictor variable of interest and infant anthropometry as the dependent variable.

RESULTS

At risk of overweight, overweight, and obese was present in a total of 62 (19.6%) infants. In both unadjusted and adjusted models, infants in the weekend catch-up sleep group (30.4%) and those in the weekend sleep curtailment group (34.5%) had significantly higher weight-to-length ratios, body mass index, weight-for-age z-scores, and weight velocity of 6-month increments z-scores when compared with infants in the regular sleep group (35.1%, all p < 0.05).

CONCLUSIONS

Differences in weekday-weekend sleep exist as early as in the first 6 months of life, and both catch-up sleep and sleep curtailment over the weekend is associated with higher measures of weight and length in infants.

PRACTICE IMPLICATIONS

Sleep assessments in well-child checkups should include not only global assessments of average sleep duration but also address sleep patterns and their regularity.

Effects of the healthy start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents

Poor sleep and psychological stress are obesity determinants that are rarely included in obesity prevention programs. The aim was to report the effects of the Healthy Start randomized intervention on the secondary outcomes psychological stress and sleep duration and onset latency. Data was obtained from the Healthy Start randomized intervention conducted in 2009–2012 among Danish healthy weight children aged 2–6 years, who had either a high birth weight (>4,000 g), high maternal pre-pregnancy body mass index (>28 kg/m2), or low maternal educational level (≤10 years of schooling) and their parents. The intervention was designed to deliver improvements in diet and physical activity habits, optimization of sleep habits, and reduction of psychological family stress. The average intervention period was 15 months. Children with information on a 7-day sleep record, sleep onset latency, Strengths and Difficulties Questionnaire (SDQ), and a modified version of Parenting Stress Index (PSI) were included. The effects of the intervention on sleep habits, PSI scores, SDQ Total Difficulties (SDQ-TD) and Pro-social Behavior scores, and 95% Confidence Intervals (95% CI) were analyzed using linear regression intention-to-treat (n = 543 (intervention group n = 271, control group n = 272)) analyses. No statistically significant effects on sleep duration, sleep onset latency, PSI score, or SDQ Pro-social Behavior score were observed. Values both before and after the intervention were within the normal range both for children in the intervention and children in the control group. Mean change in SDQ-TD was 0.09 points (95% CI -0.57;0.59) in the intervention group, and -0.69 points (95% CI -1.16; -0.23) in the control group (p = 0.06). In conclusion, there were no intervention effects in relation to sleep duration, sleep onset latency, PSI score, or SDQ Pro-social behavior. There was an indication that children in the intervention group had slightly more behavioral problems than the control group after the intervention, but values were within normal range both before and after the intervention, and the difference is not considered to be clinically meaningful.

REM Sleep: An Unknown Indicator of Sleep Quality

Standard polysomnographic analysis of sleep has not provided evidence of an objective measure of sleep quality; however, factors such as sleep duration and sleep efficiency are those more consistently associated with the subjective perception of sleep quality. Sleep reduction as currently occurs in our 24/7 society has had a profound impact on sleep quality; the habitual sleep period should fit within what is a limited nighttime window and may not be sufficient to satisfy the whole sleep process; moreover, the use of artificial light during the evening and early night hours can delay and disturb the circadian rhythms, especially affecting REM sleep. The correct phase relationship of the sleep period with the circadian pacemaker is an important factor to guarantee adequate restorative sleep duration and sleep continuity, thus providing the necessary background for a good night's sleep. Due to the fact that REM sleep is controlled by the circadian clock, it can provide a window-like mechanism that defines the termination of the sleep period when there is still the necessity to complete the sleep process (not only wake-related homeostasis) and to meet the circadian end of sleep timing. An adequate amount of REM sleep appears necessary to guarantee sleep continuity, while periodically activating the brain and preparing it for the return to consciousness.

Sleep and lifestyle in young adult monozygotic twin pairs discordant for body mass index

OBJECTIVES

The causal nature of the sleep-obesity association is unclear. To control for potential confounding by genes and shared environment, we studied monozygotic twin pairs discordant for body mass index (BMI). First, we investigated sleep in relation to BMI. Second, we examined associations of objective and subjective sleep duration and sleep debt (objective or subjective sleep duration minus subjective sleep need) with eating behaviors and physical activity (PA).

DESIGN

Cross-sectional study.

SETTING

Finnish twins in everyday life circumstances.

PARTICIPANTS

Seventy-four healthy young adult monozygotic twin pairs, of whom 36 were BMI-discordant (∆BMI ≥ 3 kg/m²).

MEASUREMENTS

Clinical measurements estimated BMI and body composition. Sleep, eating, and PA behaviors were measured by self-report and actigraphy.

RESULTS

Compared to co-twins with lower BMI, co-twins with higher BMI reported shorter sleep (P = .043), more snoring (P = .0093), and greater tiredness (P = .0013) and trended toward eveningness (P = .036). Actigraphy-measured sleep duration correlated highly within BMI-discordant twin pairs (r = 0.63, P = .004). Subjective sleep debt was consistently positively associated with disinhibited eating and binge eating, but not with BMI. Subjective and objective sleep debt had negative correlations with moderate-to-vigorous PA.

CONCLUSIONS

Twins with higher BMI showed less favorable sleep characteristics than their co-twins with lower BMI. Subjective sleep debt is a potential target for intervention to reduce eating and PA behaviors that promote weight gain. Experimental studies could elucidate mechanisms underlying tiredness in individuals with higher BMI and investigate causal relationships between sleep debt, BMI, and lifestyle.

The Mysterious Island: Insula and Its Dual Function in Sleep and Wakefulness

In the recent sleep studies, it was shown that afferentation of many cortical areas switches during sleep to the interoceptive one. However, it was unclear whether the insular cortex, which is often considered as the main cortical visceral representation, maintains the same effective connectivity in both states of vigilance, or processes interoceptive information predominantly in one state. We investigated neuronal responses of the cat insular cortex to electrical stimulations of the intestinal wall delivered during wakefulness and natural sleep. Marked increase was observed in the number of insular neurons responding to this stimulation in sleep comparing to wakefulness, and enlarged amplitudes of evoked local field potentials were found as well. Moreover, most of the cells responding to intestinal stimulation in wakefulness never responded to identical stimuli during sleep and vice versa. It was also shown that applied low intensity intestinal stimulations had never compromised sleep quality. In addition, experiments with microstimulation of the insular cortex and recording of intestinal myoelectric activity demonstrated that effective insula-to-gut propagation also happened only during sleep. On the other hand, the same insular stimulations in wakefulness led to contractions of orofacial muscles. The evoked face movements gradually disappeared in the course of sleep development. These findings demonstrate that pattern of efficient afferent and efferent connections of the insular cortex changes with transition from wakefulness to sleep.

Sleep disorders related to nutrition and digestive diseases: a neglected clinical condition

Sleep disturbances often result from inappropriate lifestyles, incorrect dietary habits, and/or digestive diseases. This clinical condition, however, has not been sufficiently explored in this area. Several studies have linked the circadian timing system to the physiology of metabolism control mechanisms, energy balance regulation, and nutrition. Sleep disturbances supposedly trigger digestive disorders or conversely represent specific clinical manifestation of gastrointestinal (GI) diseases. Poor sleep may worsen the symptoms of GI disorders, affecting the quality of life. Conversely, short sleep may influence dietary choices, as well as meal timing, and the circadian system drives temporal changes in metabolic patterns. Emerging evidence suggests that patients with inappropriate dietary habits and chronic digestive disorders often sleep less and show lower sleep efficiency, compared with healthy individuals. Sleep disturbances may thus represent a primary symptom of digestive diseases. Further controlled trials are needed to fully understand the relationship between sleep disturbances, dietary habits, and GI disorders. It may be also anticipated that the evaluation of sleep quality may prove useful to drive positive interventions and improve the quality of life in a proportion of patients. This review summarizes data linking sleep disorders with diet and a series of disease including gastro-esophageal reflux disease, peptic disease, functional gastrointestinal disorders, inflammatory bowel diseases, gut microbiota alterations, liver and pancreatic diseases, and obesity. The evidence supporting the complex interplay between sleep dysfunction, nutrition, and digestive diseases is discussed.

Onset of Workplace Bullying and Risk of Weight Gain: A Multicohort Longitudinal Study

OBJECTIVE

This study aimed to examine the onset of workplace bullying as a risk factor for BMI increase.

METHODS

Repeated biennial survey data from three Nordic cohort studies were used, totaling 46,148 participants (67,337 participant observations) aged between 18 and 65 who did not have obesity and who were not bullied at the baseline. Multinomial logistic regression was applied for the analysis under the framework of generalized estimating equations.

RESULTS

Five percent reported onset of workplace bullying within 2 years from the baseline. In confounder-adjusted models, onset of workplace bullying was associated with a higher risk of weight gain of ≥ 1 BMI unit (odds ratio = 1.09; 95% CI: 1.01-1.19) and of ≥ 2.5 BMI units (odds ratio = 1.24; 95% CI: 1.06-1.45). A dose-response pattern was observed, and those exposed to workplace bullying more frequently showed a higher risk (P_trend  = 0.04). The association was robust to adjustments, restrictions, stratifications, and use of relative/absolute scales for BMI change.

CONCLUSIONS

Participants with exposure to the onset of workplace bullying were more likely to gain weight, a possible pathway linking workplace bullying to increased long-term risk of type 2 diabetes.

A preliminary investigation of the effects of short-duration, vigorous exercise following sleep restriction, fragmentation and extension on appetite and mood in inactive, middle-aged men

This preliminary study aimed to investigate the effect of exercise on appetite and mood following multiple days of sleep disruption (restriction [RES], fragmentation [FRAG]) or sleep extension (EXT), compared to normal sleep (CONT) in inactive, middle-aged men. Nine men completed four randomised trials initiated by 3 nights (day 1-3) of CONT (6.5-8 hr), RES (4 hr), FRAG (6.5-8 hr, interrupted at 2-hr intervals) or EXT (10 hr). On day 4 between 08:30 and 11:00 hours, perceived appetite, food cravings, appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine-tyrosine [PYY]_total ), glucose, mood states and wellness (stress, fatigue, soreness, and mood) were assessed before (post-sleep manipulation [SM]) and after (post-exercise [EX]) a 20-min vigorous cycling bout (rating of perceived exertion: 15). There was no effect of sleep manipulation or exercise on perceived appetite (p = .34-.62). Some aspects of food craving were altered after RES and EXT, with vigorous exercise attenuating the desire for sweet foods in RES (p = .12). PYY_total was lower after RES compared to EXT and FRAG (p = .03), but was unaltered by exercise (p = .03). Ghrelin was higher for RES and EXT compared to CONT and FRAG after exercise (p = .001-.03). Total wellness was reduced and total mood disturbance (TMD) was higher after RES and FRAG compared to CONT and EXT (p ≤ .05). However, vigorous exercise countered these changes, with wellness and TMD remaining significantly impaired for FRAG compared to EXT only at this time (p = .02-.03). Vigorous exercise mitigates some aspects of food cravings and counters the impaired mood states that exist after multiple days of restricted and fragmented sleep.

Sleep duration and quality are not associated with brown adipose tissue volume or activity-as determined by 18F-FDG uptake, in young, sedentary adults

Study Objectives

Short sleep duration and sleep disturbances have been related to obesity and metabolic disruption. However, the behavioral and physiological mechanisms linking sleep and alterations in energy balance and metabolism are incompletely understood. In rodents, sleep regulation is closely related to appropriate brown adipose tissue (BAT) thermogenic activity, but whether the same is true in humans has remained unknown. The present work examines whether sleep duration and quality are related to BAT volume and activity (measured by ¹⁸F-FDG) and BAT radiodensity in humans.

Methods

A total of 118 healthy adults (69% women, 21.9 ± 2.2 years, body mass index: 24.9 ± 4.7 kg/m²) participated in this cross-sectional study. Sleep duration and other sleep variables were measured using a wrist-worn accelerometer for seven consecutive days for 24 hours per day. The Pittsburgh Sleep Quality Index was used to assess sleep quality. All participants then underwent a personalized cold exposure to determine their BAT volume, activity, and radiodensity (a proxy of the intracellular triglyceride content), using static positron emission tomography combined with computed tomography (PET/CI) scan.

Results

Neither sleep duration nor quality was associated with BAT volume or activity (the latter represented by the mean and peak standardized ¹⁸F-FDG uptake values) or radiodensity (all p > .1). The lack of association remained after adjusting the analyses for sex, date of PET/CT, and body composition.

Conclusions

Although experiments in rodent models indicate a strong relationship to exist between sleep regulation and BAT function, it seems that sleep duration and quality may not be directly related to the BAT variables examined in the present work.

Clinical Trial Registration

NCT02365129 (ClinicalTrials.gov).

Association between sleep quality and time with energy metabolism in sedentary adults

The aim of the present study was to investigate the relationship of sleep quality and time with basal metabolic rate (BMR) and fuel oxidation in basal conditions and during exercise in sedentary middle-aged adults. We also studied the mediation role of dietary intake and adherence to the traditional Mediterranean Diet in the relationship between sleep parameters and energy metabolism parameters.A secondary analysis of the FIT-AGEING study was undertaken. 70 middle-aged sedentary adults (40-65 years old) participated in the present study. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and wrist accelerometers (ActiSleep, Actigraph, Pensacola, Florida, USA) for 7 consecutive days. BMR was measured with indirect calorimetry and fuel oxidation was estimated through stoichiometric equations. Maximal fat oxidation was determined by a walking graded exercise test and dietary intake with 24 h recalls. Adherence to the traditional Mediterranean diet was assessed through the PREDIMED questionnaire. PSQI global score (poor sleep quality) was associated with lower basal fat oxidation (BFox), both expressed in g/min and as a percentage of BMR, independently of confounders. We did not find any association between other sleep and energy metabolism parameters. No mediating role of the dietary intake or PREDIMED global score was observed in the association of PSQI and BFox. In conclusion, our study showed that a subjective poor sleep quality was associated with lower BFox, which is not mediated by dietary intake in sedentary adults.

Marrow Fat-Secreted Factors as Biomarkers for Osteoporosis

PURPOSE OF REVIEW

The age-related accumulation of bone marrow adipose tissue (BMAT) negatively impacts bone metabolism and hematopoiesis. This review provides an overview about BMAT-secreted factors as biomarkers for BMAT accumulation and osteoporosis risk.

RECENT FINDINGS

The adipokines leptin and adiponectin are regulators of BMAT. It remains to be clarified if locally produced adipokines substantially contribute to their peripheral serum levels and if they influence bone metabolism beyond that of extraosseous adipokine production. Existing data also suggests that BMAT disturbs bone metabolism primarily through palmitate-mediated toxic effects on osteoblasts and osteocytes, including dysregulated autophagy and apoptosis. BMAT-secreted factors are important modulators of bone metabolism. However, the majority of our understanding about MAT-secreted factors and their paracrine and endocrine effects is derived from in vitro studies and animal experiments. Therefore, more research is needed before BMAT-secreted biomarkers can be applied in medical practice.

Working against the biological clock: a review for the Occupational Physician

The master clock of the biological rhythm, located in the suprachiasmatic nucleus of the anterior hypothalamus, synchronizes the molecular biological clock found in every cell of most peripheral tissues. The human circadian rhythm is largely based on the light-dark cycle. In night shift workers, alteration of the cycle and inversion of the sleep-wake rhythm can result in disruption of the biological clock and induce adverse health effects. This paper offers an overview of the main physiological mechanisms that regulate the circadian rhythm and of the health risks that are associated with its perturbation in shift and night workers. The Occupational Physician should screen shift and night workers for clinical symptoms related to the perturbation of the biological clock and consider preventive strategies to reduce the associated health risks.

High-intensity interval exercise induces greater acute changes in sleep, appetite-related hormones, and free-living energy intake than does moderate-intensity continuous exercise

The aim of this study was to compare the effect of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on sleep characteristics, appetite-related hormones, and eating behaviour. Eleven overweight, inactive men completed 2 consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400–1600 h), participants completed a 30-min exercise bout: either (i) MICE (60% peak oxygen consumption) or (ii) HIIE (60 s of work at 100% peak oxygen consumption: 240 s of rest at 50% peak oxygen consumption), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, and peptide tyrosine tyrosine) and glucose before exercise, 30 min after exercise, and the next morning after exercise; PSG sleep stages; and actigraphy (sleep quantity and quality); in addition, self-reported sleep and food diaries were recorded until 48 h after exercise. There were no between-trial differences for time in bed (p = 0.19) or total sleep time (p = 0.99). After HIIE, stage N3 sleep was greater (21% ± 7%) compared with BASE (18% ± 7%; p = 0.02). In addition, the number of arousals during rapid eye movement sleep were lower after HIIE (7 ± 5) compared with BASE (11 ± 7; p = 0.05). Wake after sleep onset was lower following MICE (41 min) compared with BASE (56 min; p = 0.02). Acylated ghrelin was lower and glucose was higher at 30 min after HIIE when compared with MICE (p ≤ 0.05). There were no significant differences between conditions in terms of total energy intake (p ≥ 0.05). HIIE appears to be more beneficial than MICE for improving sleep quality and inducing favourable transient changes in appetite-related hormones in overweight, inactive men. However, energy intake was not altered regardless of exercise intensity.

Sleep disturbances and daytime fatigue: data from the Brazilian National Health Survey, 2013

This study aims to describe the prevalence of sleep disturbances and daytime fatigue and their association with socio-demographic and behavioral factors. Data from the Brazilian National Health Survey conducted in 2013 with 60,202 adults (≥ 18 years old) were used. The outcomes evaluated were self-reported sleep disturbances and daytime fatigue in the last two weeks. Sleep disturbance was defined as the presence of difficulty to fall asleep, frequently waking up during the night or sleeping more than usual; daytime fatigue was defined as the presence of not feeling rested and motivated during the day, feeling tired and lacking energy. Sociodemographic, lifestyle and chronic health aspects were explored as exposures for both outcomes. Prevalence of sleep disturbances and daytime fatigue were 14.9% (14.4-15.4) and 11.9% (11.4-12.3), respectively. Both outcomes were more common in women, older people, people with no formal education, smokers and among physically inactive individuals. The association with education was inverse (the highest the level of education the lower the prevalence ratio - PR - of sleep disturbances and daytime fatigue; adjusted p-value for trend < 0.001). Prevalence of sleep disturbances combined with daytime fatigue was 6.7% (6.4-7.1) and was about 6 times higher among those with three or more chronic health disturbances (PR = 6.2; 95%CI: 5.3-7.2). Strategies to decrease the prevalence of sleep disturbances and daytime fatigue should be encouraged and focused on chronically ill individuals that share other modifiable risk factors.

Cross-sectional associations of objectively assessed sleep duration with physical activity, BMI and television viewing in German primary school children

BACKGROUND

The global incidence of overweight and obesity has increased dramatically among children and adolescents over the past decades. Insufficient sleep duration and physical inactivity are known risk factors for overweight and obesity in children. To engage children in a healthier lifestyle knowledge about associations of sleep duration and behavioural aspects in children are vital. Therefore, this study investigated the mentioned associations in German primary school children.

METHODS

Data of 308 first and second graders (7.1 ± 0.6 years) was used; children's anthropometric data were taken during a school visit. Children's physical activity (PA) and sleep duration were assessed objectively (Actiheart©, CamNtech Ltd., Cambridge, UK); children's daily television time and socio-demographic data were collected via parental questionnaire. Linear mixed-effects regression models as well as logistic regressions were used to determine associations of PA, television viewing, age, gender, BMI z-scores and socio-economic variables on sleep duration.

RESULTS

In linear regression models young age and not having a migration background were significantly associated with long sleep duration (p < 0.001). In logistic regressions, long night time sleep (≥10:08 h; compared to medium and short sleep duration) was significantly associated with not reaching the PA guideline (OR 0.60 [0.36;0.99]), daily television viewing of less than one hour (OR 0.44 [0.24;0.80]), young age (OR 0.38 [0.21;067]), a high parental education level (OR 0.52 [0.27;0.99]) and the lack of migration background (OR 0.21 [0.10;0.48]). However, if controlling for age, gender, parental education level and migration background, reaching the PA guideline stayed no longer significantly associated with a tertiary sleep level.

CONCLUSIONS

Children in the highest sleep category showed a negative association with reaching the PA guideline and a positive association with daily television viewing. This therefore adds to previously primarily subjectively assessed associations of sleep and risk factors for obesity (related behaviours) with a detailed insight based on objective data. Hence, interventions trying to decrease children's BMI and television viewing should also aim at extending children's night-time sleep and inform parents about the importance of sufficient sleep during childhood.

TRIAL REGISTRATION

DRKS-ID: DRKS00000494 .

Cold-inducible RNA-binding protein (CIRBP) adjusts clock-gene expression and REM-sleep recovery following sleep deprivation

Sleep depriving mice affects clock-gene expression, suggesting that these genes contribute to sleep homeostasis. The mechanisms linking extended wakefulness to clock-gene expression are, however, not well understood. We propose CIRBP to play a role because its rhythmic expression is i) sleep-wake driven and ii) necessary for high-amplitude clock-gene expression in vitro. We therefore expect Cirbp knock-out (KO) mice to exhibit attenuated sleep-deprivation-induced changes in clock-gene expression, and consequently to differ in their sleep homeostatic regulation. Lack of CIRBP indeed blunted the sleep-deprivation incurred changes in cortical expression of Nr1d1, whereas it amplified the changes in Per2 and Clock. Concerning sleep homeostasis, KO mice accrued only half the extra REM sleep wild-type (WT) littermates obtained during recovery. Unexpectedly, KO mice were more active during lights-off which was accompanied with faster theta oscillations compared to WT mice. Thus, CIRBP adjusts cortical clock-gene expression after sleep deprivation and expedites REM-sleep recovery.

Sleep duration and quality are associated with eating behavior in low-income toddlers

OBJECTIVE

The present study examined whether different sleep health parameters (duration, timing, and quality) are associated with obesity-related eating behaviors including emotional overeating, food responsiveness, enjoyment of food, satiety responsiveness, and eating in the absence of hunger (EAH), during toddlerhood.

DESIGN

Among 134 low-income 33-month-old children, parents reported on child sleep parameters, including sleep quality (Children's Sleep Wake Scale; CSWS) and usual bedtimes and wake times on weekdays and weekends (weeknight sleep duration, weekday-to-weekend bedtime delay). Child eating behaviors were assessed using both observed and parent-report measures. Child Emotional Overeating, Food Responsiveness, Enjoyment of Food, and Satiety Responsiveness were measured by parent report using the Child Eating Behavior Questionnaire-Toddler. Observed child EAH was evaluated by measuring kilocalories of palatable foods consumed following a meal. Multivariable linear regression was used to examine the associations between sleep parameters and eating behaviors.

RESULTS

Poorer child sleep quality was associated with greater Emotional Overeating (standardized β = -0.20 (SE 0.09), p < .05) and greater Food Responsiveness (β = -0.18 (SE 0.09), p < .05). Shorter child nighttime sleep duration was associated with greater EAH kcal consumed (standardized β = -0.22 (SE 0.09), p < .05). Child bedtime delay was not associated with any of the eating behaviors, and no child sleep variables were associated with either Enjoyment of Food or Satiety Responsiveness.

CONCLUSIONS

Shorter nocturnal sleep duration and poorer sleep quality during toddlerhood were associated with some, but not all, of the obesity-related eating behaviors. Poor sleep health may promote childhood obesity risk through different eating behavior pathways. As children growing up in poverty may experience greater sleep decrements, sleep duration and sleep quality may be important targets for intervention among low-income families with young children.

Neuroendocrine Control of Sleep

Sleep is a phenomenon in animal behavior as enigmatic as it is ubiquitous, and one deeply tied to endocrine function. Though there are still many unanswered questions about the neurochemical basis of sleep and its functions, extensive interactions have been identified between sleep and the endocrine system, in both the endocrine system's effect on sleep and sleep's effect on the endocrine system. Unfortunately, until recent years, much research on sleep behavior largely disregarded its connections with the endocrine system. Use of both clinical studies and rodent models to investigate interactions between neuroendocrine function, including biological sex, and sleep therefore presents a promising area of further exploration. Further investigation of the neurobiological and neuroendocrine basis of sleep could have wide impact on a number of clinical and basic science fields. In this review, we summarize the state of basic sleep biology and its connections to the field of neuroendocrine biology, as well as suggest key future directions for the neuroendocrine regulation of sleep that may significantly impact new therapies for sleep disorders in women and men.

Joining Parents' Bed at Night and Overweight among 2- to 6-Year-Old Children - Results from the 'Healthy Start' Randomized Intervention

OBJECTIVE

Parental and child co-sleeping has been suggested as a risk factor for short sleep duration and poor sleep quality that may lead to overweight. We examined if joining parent's bed during night was associated with child overweight.

METHODS

Cross-sectional data from the 'Healthy Start' study including 635 2- to 6-year-old Danish children, who were all considered obesity prone. Of these, 496 children had complete information on BMI and whether the child joined parents' bed during night and if so, how frequently. International cut-offs for overweight according to age and gender were applied, and logistic regression was used to estimate odds ratio (OR) and 95% Confidence Intervals (CI). Analyses were adjusted for the child's age and gender, overall family stress, parental educational level, and parental BMI.

RESULTS

Children who did not join their parent's bed were more likely to be overweight compared to children who did (OR 1.75 (95% CI 0.99-3.10)). Children who rarely joined their parents' bed had OR 2.74 of being overweight (95% CI 1.01-7.44) compared to children who joined every night.

CONCLUSION

Children who rarely joined parents' bed during night were almost three times more likely to be overweight than those who joined every night.

Long Sleep Duration and Social Jetlag Are Associated Inversely with a Healthy Dietary Pattern in Adults: Results from the UK National Diet and Nutrition Survey Rolling Programme Y1⁻4

Limited observational studies have described the relationship between sleep duration and overall diet. The present study investigated the association between sleep duration on weekdays or social jetlag and empirically derived dietary patterns in a nationally representative sample of UK adults, aged 19⁻64 years old, participating in the 2008⁻2012 UK National Diet and Nutrition Survey Rolling Programme. Survey members completed between three to four days of dietary records. Sleep duration on weekdays was categorized into tertiles to reflect short, normal, and long sleep duration. Social jetlag was calculated as the difference between sleep duration on weekends and weekdays. The association between sleep duration/social jetlag and dietary patterns, derived by principal components analysis, was assessed by regressing diet on sleep, whilst accounting for the complex survey design and adjusting for relevant confounders. Survey members in the highest tertile of sleep duration had on average a 0.45 (95% Confidence Interval (CI) -0.78, -0.12) lower healthy dietary pattern score, compared to middle tertile (p = 0.007). There was an inverted u-shaped association between social jetlag and the healthy dietary pattern, such that when sleep on weekends exceeded weekday sleep by 1 h 45 min, scores for indicating a healthy dietary pattern declined (p = 0.005). In conclusion, long sleep duration on weekdays and an increased social jetlag are associated with a lower healthy dietary pattern score. Further research is required to address factors influencing dietary patterns in long sleepers.

Brown adipose tissue plays a central role in systemic inflammation-induced sleep responses

We previously identified brown adipose tissue (BAT) as a source of sleep-inducing signals. Pharmacological activation of BAT enhances sleep while sleep loss leads to increased BAT thermogenesis. Recovery sleep after sleep loss is diminished in mice that lack uncoupling protein 1 (UCP-1), and also in wild-type (WT) mice after sensory denervation of the BAT. Systemic inflammation greatly affects metabolism and the function of adipose tissue, and also induces characteristic sleep responses. We hypothesized that sleep responses to acute inflammation are mediated by BAT-derived signals. To test this, we determined the effects of systemic inflammation on sleep and body temperature in UCP-1 knockout (KO) and WT mice. Intraperitoneal injections of lipopolysaccharide, tumor necrosis factor-α, interleukin-1 beta and clodronate containing liposomes were used to induce systemic inflammation. In WT animals, non-rapid-eye movement sleep (NREMS) was elevated in all four inflammatory models. All NREMS responses were completely abolished in UCP-1 KO animals. Systemic inflammation elicited an initial hypothermia followed by fever in WT mice. The hypothermic phase, but not the fever, was abolished in UCP-1 KO mice. The only recognized function of UCP-1 is to promote thermogenesis in brown adipocytes. Present results indicate that the presence of UCP-1 is necessary for increased NREMS but does not contribute to the development of fever in systemic inflammation.

Association of sleep impairments and gastrointestinal disorders in the context of the visceral theory of sleep

It was noticed long ago that sleep disorders or interruptions to the normal sleep pattern were associated with various gastrointestinal disorders. We review the studies which established the causal link between these disorders and sleep impairment. However, the mechanism of interactions between the quality of sleep and gastrointestinal pathophysiology remained unclear. Recently, the visceral theory of sleep was formulated. This theory proposes that the same brain structures, and particularly the same cortical sensory areas, which in wakefulness are involved in processing of the exteroceptive information, switch during sleep to the processing of information coming from various visceral systems. We review the studies which demonstrated that neurons of the various cortical areas (occipital, parietal, frontal) during sleep began to fire in response to activation coming from the stomach and small intestine. These data demonstrate that, during sleep, the computational power of the central nervous system, including all cortical areas, is engaged in restoration of visceral systems. Thus, the general mechanism of the interaction between quality of sleep and health became clear.

The Cost of Inadequate Sleep among On-Call Workers in Australia: A Workplace Perspective

On-call or stand-by is becoming an increasingly prevalent form of work scheduling. However, on-call arrangements are typically utilised when workloads are low, for example at night, which can result in inadequate sleep. It is a matter of concern that on-call work is associated with an increased risk of workplace injury. This study sought to determine the economic cost of injury due to inadequate sleep in Australian on-call workers. The prevalence of inadequate sleep among on-call workers was determined using an online survey, and economic costs were estimated using a previously validated costing methodology. Two-thirds of the sample (66%) reported obtaining inadequate sleep on weekdays (work days) and over 80% reported inadequate sleep while on-call. The resulting cost of injury is estimated at $2.25 billion per year ($1.71-2.73 billion). This equates to $1222 per person per incident involving a short-term absence from work; $2.53 million per incident classified as full incapacity, and $1.78 million for each fatality. To the best of our knowledge this is the first study to quantify the economic cost of workplace injury due to inadequate sleep in on-call workers. Well-rested employees are critical to safe and productive workplace operations. Therefore, it is in the interest of both employers and governments to prioritise and invest far more into the management of inadequate sleep in industries which utilise on-call work arrangements.

Improving Cardiometabolic Health with Diet, Physical Activity, and Breaking Up Sitting: What about Sleep?

Cardiometabolic disease poses a serious health and economic burden worldwide and its prevalence is predicted to increase. Prolonged sitting, lack of physical activity, poor diet, and short sleep duration are ubiquitous behaviors in modern society, and all are independent risk factors in the development of cardiometabolic disease. Existing evidence demonstrates that breaking up prolonged periods of sitting is beneficial for cardiometabolic health, however, studies have not controlled for prior sleep duration. This article examines how prolonged sitting and short sleep duration independently contribute to cardiometabolic risk, and how breaking up sitting and obtaining adequate sleep may reduce this risk. We suggest that as prolonged sitting and short sleep duration influence the same cardiometabolic parameters, there is potential for short sleep to attenuate the positive impact of breaking up prolonged sitting with physical activity. Likewise, breaking up prolonged sitting and obtaining adequate sleep together could improve predictors of cardiometabolic disease, i.e., the combined effect may be stronger than either alone. To explore these perspectives, we propose a research agenda to investigate the relationship between breaking up prolonged sitting with physical activity and short sleep duration. This will provide an evidence-base for informing the design of interventions to reduce the burden of cardiometabolic disease on communities worldwide.

Chronic sleep restriction differentially affects implicit biases toward food among men and women: preliminary evidence

Chronic sleep restriction and obesity are two major public health concerns. This study investigated how chronic sleep restriction changes implicit attitudes towards low- and high-calorie foods. In a randomized, counterbalanced cross-over design, 17 participants (eight females, nine males) underwent two laboratory testing sessions where they were either sleep-restricted for 3 weeks (i.e. underwent three weekly cycles of 5 nights of 4 h of sleep followed by 2 nights of 8 h of sleep opportunity) or received 3 weeks of control sleep (i.e. 8 h of sleep opportunity per night for 3 weeks). There was evidence for a significant sleep condition x sex interaction (F_{(1, 20)}  = 4.60, P = 0.04). After chronic sleep restriction, men showed a trend towards a significant decrease in their implicit attitudes favouring low-calorie foods (P = 0.08), whereas women did not show a significant change (P = 0.16). Men may be at increased risk of weight gain when sleep-deprived due to a reduced bias towards low-calorie foods.

Later School Start Times: What Informs Parent Support or Opposition?

STUDY OBJECTIVES

To investigate parental knowledge about adolescent sleep needs, and other beliefs that may inform their support for or objection to later school start times.

METHODS

In 2014, we conducted a cross-sectional, Internet-based survey of a nationally representative sample of parents as part of the C.S. Mott Children's Hospital National Poll on Children's Health. Parents with teens aged 13-17 years reported their children's sleep patterns and school schedules, and whether the parents supported later school start times (8:30 am or later). Responses associated with parental support of later school start times were examined with logistic regression analysis.

RESULTS

Overall, 88% of parents reported school start times before 8:30 am, and served as the analysis sample (n = 554). In this group, 51% expressed support for later school start times. Support was associated with current school start times before 7:30 am (odds ratio [OR] = 3.1 [95% confidence interval (CI) 1.2, 8.4]); parental opinion that their teen's current school start time was "too early" (OR = 3.8 [1.8, 7.8]); and agreement with American Academy of Pediatrics recommendations about school start times (OR = 4.7 [2.2, 10.1]). Support also was associated with anticipation of improved school performance (OR = 3.0 [1.5, 5.9]) or increased sleep duration (OR = 4.0 [1.8, 8.9]) with later school start times. Conversely, parents who anticipated too little time for after-school activities (OR = 0.5 [0.3, 0.9]) and need for different transportation plans (OR = 0.5 [0.2, 0.9]) were often less supportive.

CONCLUSIONS

Parental education about healthy sleep needs and anticipated health benefits may increase their support for later school start times. Educational efforts should also publicize the positive experiences of communities that have made this transition, with regard to limited adverse effect on after-school activity schedules and transportation.

Obesity, Cardiorespiratory Fitness, and Self-Reported Sleep Patterns in Chilean School-Aged Children

The aims were to examine the association of sleep patterns with being overweight or obese and to analyze the association of cardiorespiratory fitness (CRF) with sleep patterns in children. The study involved 395 schoolchildren (12-13 years old). Sleep patterns were assessed with the Sleep Self-Report (SSR) questionnaire, grouped into four subscales: sleep quality, sleep-related anxiety, bedtime refusal, and sleep routines. CRF was predicted by the 20-m shuttle-run test. Logistic regression models showed that sleep-related anxiety problems predicted being overweight or obese in both sexes, and sleep quality problems predicted being overweight or obese in girls. Also, girls who had better CRF levels were less susceptible to sleep-related anxiety problems. Studies are required to determine if increasing CRF could be a possible strategy for improving sleep quality.

Desynchronization of Circadian Clocks in Cancer: A Metabolic and Epigenetic Connection

Circadian clocks are innate oscillators that drive daily rhythms in metabolism, physiology, and behavior. 24-h rhythms in gene expression, driven by core clock transcription factors, reflect the epigenetic state of the cell, which in turn is dictated by the metabolic environment. Cancer cells alter their metabolic state and gene expression and therefore are likely to tweak circadian clock function in their favor. Over the past decade, we have witnessed an extraordinary increase in systems-level studies that suggest intricate mechanistic links between the cellular metabolome and the circadian epigenome. In parallel, reprogramming of cellular clock function in cancers is increasingly evident and the role of clock genes in the development of hematological tumors, as well as their pathophysiological effects on tissues distal to the tumor, has been described. Furthermore, the interplay between components of the circadian clock, metabolic enzymes, and oncogenes is starting to be better understood, such as the close association between overexpression of the Myc oncogene and perturbation of circadian and metabolic rhythms, thus opening new avenues to treat cancers. This review article explores current knowledge on the circadian metabolome and the molecular pathways they control, with a focus on their involvement in the development of hematopoietic malignancies.

Associations Between Lifestyle Characteristics and the Presence of Nonalcoholic Fatty Liver Disease: A Case-Control Study

BACKGROUND

Dietary and physical activity (PA) habits have been suggested as important factors for nonalcoholic fatty liver disease (NAFLD). Published data are mainly focused on the effect of either diet or exercise, whereas data on other aspects like sleep remain sparse. The aim of this study was to explore potential associations between dietary intake, PA, and sleeping habits, and the presence of NAFLD.

METHODS

One hundred patients with ultrasound-proven NAFLD and 55 healthy controls matched for age, sex, and body mass index were included. Dietary habits were assessed through a semiquantitative validated food frequency questionnaire. PA level was assessed with a validated questionnaire. Total night sleep hours and duration of midday rest were also recorded. Optimal sleep duration was defined as sleep hours ≥7 and ≤9 hr/day.

RESULTS

Patients compared to controls consumed less vegetables and nuts, more sweets, drank less coffee and alcohol (all P < 0.05), and exhibited a lower level of PA (P = 0.006). PA level [odds ratio (OR) per 100 metabolic equivalent of task-min/day = 0.74, 95% confidence interval (CI) 0.61-0.89, P = 0.002] was associated with lower probability of having NAFLD, whereas sweets consumption (OR = 2.13, 95% CI 1.22-3.71, P = 0.008) was associated with increased probability, after adjusting for several confounders, including body weight status. Optimal sleep duration was marginally and inversely associated with NAFLD presence (OR = 0.38, 95% CI 0.14-1.01, P = 0.05).

CONCLUSION

Higher PA level and optimal sleep duration are associated with lower likelihood, whereas sweets consumption is associated with higher likelihood of having NAFLD. These associations are independent of body weight status and energy intake.

A "healthy diet-optimal sleep" lifestyle pattern is inversely associated with liver stiffness and insulin resistance in patients with nonalcoholic fatty liver disease

Several lifestyle habits have been described as risk factors for nonalcoholic fatty liver disease (NAFLD). Given that both healthy and unhealthy habits tend to cluster, the aim of this study was to identify lifestyle patterns and explore their potential associations with clinical characteristics of individuals with NAFLD. One hundred and thirty-six consecutive patients with ultrasound-proven NAFLD were included. Diet and physical activity level were assessed through appropriate questionnaires. Habitual night sleep hours and duration of midday naps were recorded. Optimal sleep duration was defined as sleep hours ≥ 7 and ≤ 9 h/day. Lifestyle patterns were identified using principal component analysis. Eight components were derived explaining 67% of total variation of lifestyle characteristics. Lifestyle pattern 3, namely high consumption of low-fat dairy products, vegetables, fish, and optimal sleep duration was negatively associated with insulin resistance (β = -1.66, P = 0.008) and liver stiffness (β = -1.62, P = 0.05) after controlling for age, sex, body mass index, energy intake, smoking habits, adiponectin, and tumor necrosis factor-α. Lifestyle pattern 1, namely high consumption of full-fat dairy products, refined cereals, potatoes, red meat, and high television viewing time was positively associated with insulin resistance (β = 1.66, P = 0.005), although this association was weakened after adjusting for adiponectin and tumor necrosis factor-α. A "healthy diet-optimal sleep" lifestyle pattern was beneficially associated with insulin resistance and liver stiffness in NAFLD patients independent of body weight status and energy intake.

Nighttime sleep duration and risk of nonalcoholic fatty liver disease: the Dongfeng-Tongji prospective study

BACKGROUND

To examine the association between self-reported nighttime sleep duration and nonalcoholic fatty liver disease (NAFLD) risk by comparing the incidence rates of NAFLD among healthy subjects with different sleep duration during the 5 years follow-up.

METHODS

8965 eligible NAFLD-free subjects with a mean age of 61.6 years (males, 43.4%) from Dongfeng-Tongji cohort study at baseline were enrolled in the study. Logistic regression analysis was used to estimate the association between sleep duration and incident NAFLD with potential confounders adjusted. Sleep duration was categorized into five groups: <6 h, 6-7 h, 7-8 h, 8-9 h, ≥9 h.

RESULT

During the 5-years of follow-up, a total of 2,197 participants were newly diagnosed as NAFLD. Compared with those reported 7-8 h per day of nighttime sleep, the multivariable-adjusted odds ratio (95% confidence intervals) were 1.21 (1.07-1.38) for those who sleep 8-9 h/day, and 1.31 (1.13-1.52) for those who sleep over 9 h/day. However, no significant association was found with short nightly sleep duration (<7 h/day).

CONCLUSION

Long nighttime sleep duration was associated with a modestly increased risk of NAFLD in a middle-aged and elderly Chinese population. Key messages Long nighttime sleep duration was associated with a modestly increased risk of NAFLD in a middle-aged and elderly Chinese population. The effect of long nighttime sleep on the risk of incident NAFLD was attenuated greatly by body mass index (BMI) in men.

Sleep Quality: A Pilot Study Comparing Patients With and Without Injection-Related Venous Ulcers

PURPOSE

The purposes of this study were to (a) compare sleep quality of persons with and without injection-related venous ulcers (VU) and (b) examine associations between global sleep quality with age, sex, comorbidities, pain, nutrition, physical health rating, fatigue, emotional problems, health-related quality of life, attitude toward physical activity, and number of ulcers.

DESIGN

This study used a cross-sectional design.

SUBJECTS AND SETTING

The participants included 31 patients with VU and 30 without VU (men [n = 35] and women; mean age = 54 years) who were attending an indigent clinic for wound care or general health.

METHODS

Participants were recruited from an urban clinic when they came for primary care or wound care. Questionnaires were administered at that time and included the Pittsburgh Sleep Quality Index (PSQI), Mini Nutrition Assessment, Patient Reported Outcomes Measurement Information System (PROMIS) questions about general physical health, fatigue, emotional problems, and quality of life, Brief Pain Inventory worst pain rating, Positive Attitude and Motivation for Physical Activity Scale, wound assessment, and demographic factors.

RESULTS

The 2 groups did not differ on the PSQI in terms of time going to bed, minutes to fall asleep, time awakening, hours slept, and time in bed. Those with VU compared to without VU took more medications to help sleep (P≤ .03). There were no significant differences in PSQI correlations across groups. All study variables except age, gender, and quality of life were significantly related to Global sleep disturbance score. A higher number of comorbid conditions, worse pain, poorer nutrition, poor physical health rating, greater fatigue, more emotional problems, and poor attitude toward physical activity were related to greater sleep disturbances for all participants. Both groups had mean Global PSQI scores greater than 5 (with VU = 7.83 and without VU = 8.2), indicating sleep problems.

CONCLUSIONS

Study findings suggest that sleep disturbances may be a concern in persons with VU and are related to many variables. Assessing sleep along with other aspects of wound care may provide a more comprehensive assessment of factors affecting a person with a VU.

Insomnia predicts long-term all-cause mortality after acute myocardial infarction: A prospective cohort study

BACKGROUND

Sleep impairment such as insomnia is an established risk factor for the development of cardiovascular disease and acute myocardial infarction (AMI). The aim of the current study was to examine the association between insomnia and all-cause mortality among AMI patients.

METHODS

This prospective cohort study used data on n=732 patients recruited from September 2006 to May 2011 as part of the Västmanland Myocardial Infarction Study (VaMIS), a prospective cohort study of AMI patients living in Västmanland County, Sweden. Participants were followed up for all-cause mortality until December 9, 2015. The outcome of interest was time-to-death (TTD), with the presence of insomnia being the risk factor of main interest. Data were analyzed using a piecewise Cox regression model with change point for insomnia at two years of follow-up, adjusted for socioeconomic, lifestyle and clinical risk factors.

RESULTS

In total, n=175 (23.9%) of the participants suffered from insomnia. During a mean (SD) follow-up time of 6.0 (2.5) years (4392person-years), a total of n=231 (31.6%) participants died, n=77 (44.0%) in the insomnia group and n=154 (27.6%) in the non-insomnia group (log-rank test p<0.001). In a multiple adjusted piecewise Cox regression model, insomnia did not imply a higher risk of death during the first two years after AMI (HR 0.849; 95% CI 0.508-1.421; p=0.534). During the period after the first two years, however, insomnia implied a 1.6 times higher risk of death (HR 1.597; 95% CI 1.090-2.341; p=0.016).

CONCLUSIONS

Insomnia implies a higher risk of death among AMI patients in the long term.

Association between sleeping difficulty and type 2 diabetes in women

AIMS/HYPOTHESIS

Sleeping difficulty has been associated with type 2 diabetes in some prior studies. Whether the observed associations are independent of health behaviours, other cardiovascular risk factors or other sleep disorders is unclear.

METHODS

We analysed data from 133,353 women without diabetes, cardiovascular disease and cancer at baseline in the Nurses' Health Study (NHS, 2000-2010) and the NHSII (2001-2011). Sleeping difficulty was assessed as having difficulty falling or staying asleep 'all of the time' or 'most of the time' at baseline (2000 in NHS and 2001 in NHSII).

RESULTS

We documented 6,407 incident cases of type 2 diabetes during up to 10 years of follow-up. After adjustment for lifestyle factors at baseline, comparing women with and without sleeping difficulty, the multivariate-adjusted HR (95% CI) for type 2 diabetes was 1.45 (95% CI 1.33, 1.58), which changed to 1.22 (95% CI 1.12, 1.34) after further adjustment for hypertension, depression and BMI based on the updated repeated measurements. Women who reported all four sleep conditions (sleeping difficulty, frequent snoring, sleep duration ≤6 h and sleep apnoea in NHS or rotating shift work in NHSII) had more than a fourfold increased likelihood of type 2 diabetes (HR 4.17, 95% CI 2.93, 5.91).

CONCLUSIONS/INTERPRETATION

Sleeping difficulty was significantly associated with type 2 diabetes. This association was partially explained by associations with hypertension, BMI and depression symptoms, and was particularly strong when combined with other sleep disorders. Our findings highlight the importance of sleep disturbance in the development and prevention of type 2 diabetes.

The Link Between Inadequate Sleep and Obesity in Young Adults

The prevalence of obesity has increased dramatically over the past decade. Although an imbalance between caloric intake and physical activity is considered a key factor responsible for the increase, there is emerging evidence suggesting that other factors may be important contributors to weight gain, including inadequate sleep. Overall research evidence suggests that inadequate sleep is associated with obesity. Importantly, the strength and trajectory of the association seem to be influenced by multiple factors including age. Although limited, the emerging evidence suggests young adults might be at the center of a "perfect health storm," exposing them to the highest risk for obesity and inadequate sleep. Unfortunately, the methods necessary for elucidating the complex relationship between sleep and obesity are lacking. Uncovering the underlying factors and trajectories between inadequate sleep and weight gain in different populations may help to identify the windows of susceptibility and to design targeted interventions to prevent the negative impact of obesity and related diseases.

Sleep Restriction Enhances the Daily Rhythm of Circulating Levels of Endocannabinoid 2-Arachidonoylglycerol

STUDY OBJECTIVES

Increasing evidence from laboratory and epidemiologic studies indicates that insufficient sleep may be a risk factor for obesity. Sleep curtailment results in stimulation of hunger and food intake that exceeds the energy cost of extended wakefulness, suggesting the involvement of reward mechanisms. The current study tested the hypothesis that sleep restriction is associated with activation of the endocannabinoid (eCB) system, a key component of hedonic pathways involved in modulating appetite and food intake.

METHODS

In a randomized crossover study comparing 4 nights of normal (8.5 h) versus restricted sleep (4.5 h) in healthy young adults, we examined the 24-h profiles of circulating concentrations of the endocannabinoid 2-arachidonoylglycerol (2-AG) and its structural analog 2-oleoylglycerol (2-OG). We concomitantly assessed hunger, appetite, and food intake under controlled conditions.

RESULTS

A robust daily variation of 2-AG concentrations with a nadir around the middle of the sleep/overnight fast, followed by a continuous increase culminating in the early afternoon, was evident under both sleep conditions but sleep restriction resulted in an amplification of this rhythm with delayed and extended maximum values. Concentrations of 2-OG followed a similar pattern, but with a lesser amplitude. When sleep deprived, participants reported increases in hunger and appetite concomitant with the afternoon elevation of 2-AG concentrations, and were less able to inhibit intake of palatable snacks.

CONCLUSIONS

Our findings suggest that activation of the eCB system may be involved in excessive food intake in a state of sleep debt and contribute to the increased risk of obesity associated with insufficient sleep.

COMMENTARY

A commentary on this article appears in this issue on page 495.

Successful weight loss maintenance associated with morning chronotype and better sleep quality

It is not known whether individuals successful at long term weight loss maintenance differ in chronotype (i.e., being a "morning" or "evening" person) or sleep habits compared to those who are overweight and obese. We compared Morningness-Eveningness Questionnaire (MEQ) and Pittsburgh Sleep Quality Index scores of 690 National Weight Control Registry (NWCR) members (73 % female, 93 % white, age = 51.7 ± 12.5, BMI = 26.4 ± 5.1) to 75 enrollees in two behavioral weight loss interventions (INT; 77 % female, 88 % white, age = 55.7 ± 10.4, BMI = 36.2 ± 4.7). Controlling for age, MEQ scores were higher in NWCR than INT, p = .004, such that more NWCR than INT were morning-types and fewer were evening types, p = .014. Further, NWCR participants reported better sleep quality, longer sleep duration, and shorter latency to sleep onset compared to INT, ps < .05, and fewer NWCR participants reported <6 or <7 h of sleep, ps < .01. Future studies should examine if these factors change as a result of weight loss or are predictors of weight outcome.