Sleep Duration and Waist Circumference in Adults: A Meta-Analysis

Sleep Duration Alters Overfeeding-mediated Reduction in Insulin Sensitivity

CONTEXT

Weight gain and sleep restriction both reduce insulin sensitivity. However, it is not known if sleep duration alters glucose metabolism in response to overfeeding.

OBJECTIVE

To examine the effect of sleep duration on overfeeding-mediated alterations in carbohydrate metabolism and insulin sensitivity.

METHODS

Retrospective exploratory analysis of a longitudinal overfeeding study in healthy participants (n = 28, age: 26.9 ± 5.5 years, body mass index: 25.74 ± 2.45 kg/m2). After providing baseline study measures, participants were overfed 40% above weight maintenance calorie requirements for 8 weeks. Insulin sensitivity was determined by a 2-step hyperinsulinemic-euglycemic clamp. Baseline habitual sleep duration was estimated by accelerometry, and sleep groups were created based on median sleep duration (5.2 hours/night).

RESULTS

Overfeeding led to an average body weight gain of 7.3 ± .4 kg. Habitual sleep duration did not alter overfeeding-mediated body weight gain, fat gain, and fat distribution (all P > .15). Compared to participants with more sleep, fasting insulin (P = .01) and homeostatic model assessment for insulin resistance (P = .02) increased while fasting glucose remained unchanged (P = .68) with overfeeding in participants with shorter sleep duration. Glucose infusion rate during high insulin dose was reduced with overfeeding in participants with short sleep duration but not in participants with more sleep (P < .01).

CONCLUSION

Overfeeding mediated weight gain reduced liver, adipose, and whole-body insulin sensitivity prominently in individuals with short sleep duration but not in individuals with longer sleep duration. This suggests that promoting adequate sleep during short periods of overeating may prevent detrimental effects on glucose metabolism.

Association between sleep duration and patterns and obesity: a cross-sectional study of the 2007-2018 national health and nutrition examination survey

OBJECTIVE

We intend to explore whether sleep duration and sleep patterns were associated with obesity among the adult American population.

METHODS

Our study analyzed data from 4540 adults (2007-2008, 2015-2018) in the National Health and Nutrition Examination Survey (NHANES) database. Self-reported questionnaires were used to collect data on sleep duration, excessive daytime sleepiness, and sleep problems. The overall sleep pattern score was calculated and categorized into three types: healthy, intermediate, and poor sleep patterns. Multivariable logistic regression models were used to calculate the associations between sleep duration, sleep patterns and obesity. We further conducted linearity tests using restricted cubic splines to explore the dose-response relationship between sleep duration and obesity. Additionally, we performed stratified and interaction analyses to understand if this relationship was stable in different subgroups.

RESULTS

After adjusting for potential confounding factors, sleep duration (odds ratio [OR] = 0.91, 95% confidence interval [CI]:0.87-0.95, P < 0.001) and sleep pattern score (OR = 1.18, 95% CI: 1.1-1.27, P < 0.001) were independently associated with obesity. There was a non-linear relationship between sleep duration and obesity, with a threshold of approximately 9.73 h. The effects and CI below and above the threshold were 0.89 (0.849-0.936) and 2.023 (1.113-3.677), respectively.

CONCLUSIONS

Unhealthy sleep patterns and shorter sleep duration were positively correlated with obesity occurrence, and there was a non-linear relationship between sleep duration and the occurrence of obesity. Interventions aimed at promoting healthy sleep habits and appropriate sleep duration may be important in reducing the risk of obesity.

Exploring the Science of Shape: How Physical Activity, Sleep, and Stress Affect Body Composition

In the contemporary context of health challenges, the focus on physical health has become a social and individual priority. Within this framework, body composition emerges as one of the key determinants of physical health, with deviations from normal body composition being associated with numerous pathological conditions that can lead to serious health issues. Consequently, there is an urgent need to synthesize the available knowledge and increase awareness regarding healthy body composition and the factors that shape its components. This narrative review aims to summarize the knowledge regarding the main components of body composition and the key factors that influence their development. The fundamental morphological characteristics and functions of the primary components of body composition-including adipose tissue, muscle mass, and bone tissue-are addressed. Furthermore, the available methods for assessing body composition are outlined. The role of three key factors that influence body composition is outlined, including, but not limited to, physical activity, sleep quality, and stress levels. Additionally, hormonal fluctuations that determine body composition in relation to the variability of these factors are discussed. The review provides evidence-based information that will be valuable both for disease prevention related to non-communicable diseases and for the promotion of health strategies aimed at long-term physical well-being.

Sex differences in the relationship between short sleep duration and obesity among koreans

This cross-sectional study examined the relationship between short sleep duration and obesity by analysing data from 3,950 participants aged 40-69 years who took part in the 2003-2004 follow-up survey of the Korean Genome and Epidemiologic Study. Based on the subjective experience of morning fatigue, short sleep duration was defined as < 5 h of sleep. Short sleep duration was significantly associated with general obesity, as measured by body mass index (adjusted odds ratios [confidence intervals], 1.246 [1.016-1.529]); these associations became stronger as the severity of general obesity worsened. Analysing data separately by sex, we detected a relationship between short sleep duration and general obesity in females only. Considering the impact of age, the relationship was detected only in females aged 40-59 years old. In females aged 40-59 years, both general obesity (1.518 [1.110-2.075]) and neck obesity (1.425 [1.045-1.945]) were associated with short sleep duration. Our study established a correlation between short sleep duration and general obesity, specifically in females and those aged 40-59 years. This finding highlights the importance of adequate sleep to treat and prevent obesity in this demographic group.

The Associations Between Sleep Duration and Various Metabolic Health Indices Among Adults in the United States: A Multivariate Analysis of Variance (MANOVA) Using National Health and Nutrition Examination Survey (NHANES) 2021 to 2023 Dataset

OBJECTIVE

This study explores the associations between various sleep durations and metabolic health indices, including systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol levels, high-density lipoprotein (HDL) cholesterol, and waist circumference.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2021 to 2023, were analyzed. MANOVA and Bonferroni-adjusted ANOVAs were conducted to examine the relationships between sleep duration (sleep deprivation (≤5 h), short sleep (5-7 h), recommended sleep (7-9 h), and long sleep (>9 h)) and metabolic health indices.

RESULTS

MANOVA revealed significant group differences between sleep duration and metabolic health indices, with Wilks' Lambda (Λ) = .98, F (3, 5095) = 4.26, P < .001. Compared to recommended sleep duration, both sleep deprivation and short sleep were associated with higher DBP (Ps < .01) and waist circumference (Ps < .001), and lower HDL levels (Ps < .05) Long sleep was associated with lower HDL levels (P < .01) and lower total cholesterol (P < .01).

CONCLUSION

The study highlights the detrimental associations of both sleep deprivation and short sleep with metabolic health, such as elevated blood pressure and waist circumference, and lowered HDL cholesterol. Long sleep may also negatively impact metabolic health by reducing HDL.

Association between sleep duration and three obesity indicators among middle-aged and elderly adults: findings from the NHANES 2005-2014

Objective

Obesity has emerged as a worldwide problem. In recent years, it has been verified that there is an association between sleep duration and obesity indicators. This provides a new approach to control obesity. In this study, the relationship between duration of sleep and body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) among Americans ≥45 years old was investigated.

Methods

Data was collected from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2014. The link between sleep duration and obesity indicators was analysed using multiple regression models and weighted smoothed curve fitting. Subgroup analysis was conducted to assess the consistency of the connection between sleep duration and obesity indicators across various groups.

Results

This study involved 7,118 males and 7,265 females, with an average age of 62.09. After total adjustment, sleep duration was negatively correlated with BMI (β = -0.19, 95%CI: -0.26, -0.12), WC (β = -0.36, 95%CI: -0.53, -0.19) and WHtR (β = -0.27, 95%CI: -0.38, -0.17). Subgroup analyses revealed more significant negative associations between sleep duration and BMI, WC, and WHtR among non-Hispanic White participants, and those without diabetes and hypertension.

Conclusion

Sleep duration was significantly negatively associated with BMI, WC, and WHtR, suggesting that longer sleep duration may contribute to lower obesity indicators in middle-aged and elderly Americans. Subgroup analysis showed that their negative correlation differed between races, diabetes, or hypertension status. However, additional prospective studies are required to validate these findings and investigate potential causal relationships.

The economic costs and consequences of (insufficient) sleep: a case study from Latin America

Sleep, an essential physiological process, has long been recognized for its critical role in human health and well-being. Beyond its biological significance, recent research has highlighted the intricate interplay between sleep and economic outcomes. By constructing meticulous economic models that account for diverse factors and refining them based on empirical data and local characteristics, this study aims to provide an in-depth understanding of the significant economic toll stemming from inadequate sleep and its ramifications on various aspects of society. Here we calculated the effect of insufficient sleep on economic loss in Argentina, according to an Overlapping Generations (OLG) model that considers average sleeping length in terms of the recommended minimum and its effect on productivity and health outcomes. We considered different scenarios in which the population sleeps from six to nine hours every night. Our results indicate that if the whole adult population achieved the recommended sleep duration of at least 7 h/night, it would be associated with a 1.27% higher GDP compared to the baseline scenario, representing the most optimistic outcome. This equals about 3.7 times the total annual budget in science, and is approximately the same percentage as the actually implemented national budget for education. In summary, by bridging the usually distant realms of biology and economics, this study offers a comprehensive analysis that not only deepens our understanding of the mechanisms underlying these costs but also provides potential avenues for intervention and policy-making.

The association between weight-adjusted waist index and sleep disorders in U.S. adults: results from NHANES 2005-2008

The detrimental effects of obesity on sleep disorders have garnered a lot of interest. The weight-adjusted waist index (WWI) is a newly developed anthropometric index calculated in terms of weight and waist circumference. The body mass index has been employed to evaluate obesity in the majority of studies that connect obesity to sleep disorders. This study seeks to investigate the correlation between WWI and sleep disorders among adults in the United States. This cross-sectional study was part of the National Health and Nutrition Examination Survey and included adults aged >20 from 2005 to 2008. This study investigated the linear relationship between sleep disorders and WWI using weighted binary logistic regression models. Nonlinear relationships were characterized using smooth curve fitting and threshold effects analyses. After that, based on variables like gender, age, marital status, diabetes, hypertension, and smoking, subgroup analyses were performed. Our study included 9869 participants who were at least 20 years old. Higher WWI was linked to greater odds of sleep disorders prevalence, according to weighted binary logistic regression (odds ratio = 1.15; 95% confidence interval, 1.10, 1.20). In subgroup analyses based on age, marital status, diabetes, hypertension, and smoking, this connection remained robust. However, there were notable differences in this connection depending on gender. Furthermore, a nonlinear correlation with inflection points between WWI and sleep disorders was shown using smooth curve fitting. The nonlinear association between WWI and sleep disorders has an inflection point of 8.1 cm/√kg, as indicated by the threshold effect analyses. A higher WWI exposure may elevate the odds of sleep disorder prevalence, underscoring the importance of considering WWI in the prevention and management of sleep disorders.

Sex and Age Differences in the Effects of Food Frequency on Metabolic Parameters in Japanese Adults

Owing to differences in dietary preferences between men and women, the associations between dietary intake frequency and metabolic parameters may differ between the sexes. A retrospective observational study of the checkup findings of 3147 Japanese individuals (968 men, 2179 women) aged 20-59 years was conducted to examine differences in dietary habits and associations between food frequency and blood parameters (eGFR, HbA1c, uric acid, and lipids) by sex and age. Males were more likely to consume meat, fish, soft drinks, and alcohol, whereas women were more likely to consume soybeans, dairy products, vegetables, fruits, and snacks. Multivariate linear regression models adjusted for age and BMI revealed that meat intake frequency was positively associated with HbA1c (β = 0.007, p = 0.03) and negatively associated with eGFR (β = -0.3, p = 0.01) only in males, whereas fish intake frequency was positively associated with eGFR (β = 0.4, p = 0.005) only in females. Egg and soy intake frequencies were positively and negatively associated with non-HDL-C (egg: β = 0.6, p = 0.02; soy: β = -0.3, p = 0.03) only in females. Alcohol consumption frequency was associated with uric acid (M: β = 0.06, p < 0.001; F: β = 0.06, p < 0.001) and HDL-C (M: β = 1.0, p < 0.001; F: β = 1.3, p < 0.001) in both sexes. Future research is needed to determine whether varying the emphasis of dietary guidance by sex and age group is effective, since the effects of dietary preferences on metabolic parameters vary by age and sex.

Sleep, Health Outcomes and Body Weight (SHOW) study: a measurement burst design study on sleep and risk factors for obesity in black emerging adults in North Carolina, USA

INTRODUCTION

Black emerging adults (18-28 years) have the highest risk of short sleep duration and obesity. This increased risk may be partly explained by greater stress levels, which may result from race-related stress (racial discrimination and heightened race-related vigilance) or living in more disadvantaged home and neighbourhood environments. Insufficient sleep may also impact obesity risk via several weight-related mechanisms including energy balance, appetite and food reward, cortisol profiles and hydration status. This paper describes the rationale, design and methods for the Sleep, Health Outcomes and Body Weight (SHOW) study. This study aims to prospectively assess the effects of sleep, race-related stress and home/neighbourhood environments on weight-related mechanisms and obesity markers (body weight, waist circumference and fat mass) in 150 black emerging adults.

METHODS AND ANALYSIS

The SHOW study follows a measurement burst design that includes 3, 7-day data collection bursts (baseline, 6-month and 12-month follow-ups). Sleep is measured with three methods: sleep diary, actigraphy and polysomnography. Energy balance over 7 days is based on resting and postprandial energy expenditure measured via indirect calorimetry, physical activity via accelerometry and self-reported and ad libitum energy intake methods. Self-reported methods and blood biomarkers assess fasting and postprandial appetite profiles and a behavioural-choice task measures food reward. Cortisol awakening response and diurnal cortisol profiles over 3 days are assessed via saliva samples and chronic cortisol exposure via a hair sample. Hydration markers are assessed with 24-hour urine collection over 3 days and fasting blood biomarkers. Race-related stress is self-reported over 7 days. Home and neighbourhood environments (via the Windshield Survey) is observer assessed.

ETHICS AND DISSEMINATION

Ethics approval was granted by the University of North Carolina at Greensboro's Institutional Review Board. Study findings will be disseminated through peer-reviewed publications, presentations at scientific meetings and reports, briefs/infographics for lay and community audiences.

The measured healthy lifestyle habits among Saudi university females in Medina, Saudi Arabia: A cross-sectional study

Lifestyle plays a crucial role in shaping an individual's health outcomes, we aim to calculate the prevalence of lifestyle habits among female populations in the College of Medicine, Taibah University including poor dietary habits, lack of physical activity (PA), poor coping with stress, and impaired sleep patterns and to find factors that are correlated to them. A cross-sectional study was conducted among Saudi females at the College of Medicine, Taibah University, from January 1 to June 1, 2023. Data were collected through interviewing them using validated questionnaires assessing 5 different lifestyle domains. Statistical analysis was performed using Statistical Package for the Social Sciences version 21.0. A total of 263 cases were interviewed. The mean age was 22 ± 8.4 years old. The average sleep quality measured by the Pittsburgh Sleep Quality Index of 2.6 ± 1.1, suggesting relative difficulty in sleep quality. A total of 68.6% participated in moderate PA. Dietary habits indicated a high prevalence of consumption of sweets, and fast meals, alongside low intake of fruits and vegetables. Emotional well-being, as assessed by the World Health Organization-5 questionnaire, yielded an average score of 7.8 ± 5.7, 58.9% moderate stress, and 8% high perceived stress. Adequate sleep quality is crucial for well-being, necessitating lifestyle modifications, particularly weight management, to address sleep disorders. Varied PA levels (46% meeting recommendations) highlight the need for standardized guidelines and tailored interventions. The high prevalence of unhealthy dietary habits underscores the importance of targeted nutritional interventions. Stress prevalence (40%) emphasizes the need for individualized stress management strategies.

Short sleep duration is associated with higher risk of central obesity in adults: A systematic review and meta-analysis of prospective cohort studies

Background and Objective

The relationship between sleep duration and obesity has been the focus of numerous investigations. This systematic review and meta-analysis of prospective cohort studies aimed to assess the relationship between sleep duration, abdominal obesity, and body composition.

Methods

PubMed, Scopus, and Web of Science were searched until February 2024. Cohort studies that assessed the relationship between sleep duration at night and central obesity measures or body composition indices in adults were included. The quality of studies was assessed using the Newcastle-Ottawa scale. Random-effects meta-analysis was conducted on studies that reported risk ratio (RR) and 95% confidence intervals (CIs).

Results

Eighteen studies were eligible to be included. Eleven out of the 18 studies were not included in the analysis as 10 studies did not report RR, and in one study, the definition of short and normal sleep duration was different from others. The results of the meta-analysis indicated that short sleep duration was significantly associated with abdominal obesity (RR = 1.08; 95% CI: 1.04-1.12; I 2 = 49.1%, n = 7), but long sleep duration was not (RR = 1.02; 95% CI: 0.83-1.24; I 2 = 98.2%, n = 6).

Conclusions

Short sleep duration was associated with a slightly higher risk of central obesity, while long sleep duration was not.

Nutraceutical blends predict enhanced health via microbiota reshaping improving cytokines and life quality: a Brazilian double-blind randomized trial

Nutraceutical interventions supporting microbiota and eliciting clinical improvements in metabolic diseases have grown significantly. Chronic stress, gut dysbiosis, and metainflammation have emerged as key factors intertwined with sleep disorders, consequently exacerbating the decline in quality of life. This study aimed to assess the effects of two nutraceutical formulations containing prebiotics (fructooligosaccharides (FOS), galactooligosaccharides (GOS), yeast β-glucans), minerals (Mg, Se, Zn), and the herbal medicine Silybum marianum L. Gaertn., Asteraceae (Milk thistle or Silymarin). These formulations, namely NSupple (without silymarin) and NSupple_Silybum (with silymarin) were tested over 180 days in overweight/obese volunteers from Brazil's southeastern region. We accessed fecal gut microbiota by partial 16S rRNA sequences; cytokines expression by CBA; anthropometrics, quality of life and sleep, as well as metabolic and hormonal parameters, at baseline (T0) and 180 days (T180) post-supplementation. Results demonstrated gut microbiota reshaping at phyla, genera, and species level post-supplementation. The Bacteroidetes phylum, Bacteroides, and Prevotella genera were positively modulated especially in the NSupple_Silybum group. Gut microbiota modulation was associated with improved sleep patterns, quality-of-life perception, cytokines expression, and anthropometric parameters post-supplementation. Our findings suggest that the nutraceutical blends positively enhance cardiometabolic and inflammatory markers. Particularly, NSupple_Silybum modulated microbiota composition, underscoring its potential significance in ameliorating metabolic dysregulation. Clinical trial registry number: NCT04810572. 23/03/2021.

Current Perspectives: Obesity and Neurodegeneration - Links and Risks

Obesity is increasing in prevalence across all age groups. Long-term obesity can lead to the development of metabolic and cardiovascular diseases through its effects on adipose, skeletal muscle, and liver tissue. Pathological mechanisms associated with obesity include immune response and inflammation as well as oxidative stress and consequent endothelial and mitochondrial dysfunction. Recent evidence links obesity to diminished brain health and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Both AD and PD are associated with insulin resistance, an underlying syndrome of obesity. Despite these links, causative mechanism(s) resulting in neurodegenerative disease remain unclear. This review discusses relationships between obesity, AD, and PD, including clinical and preclinical findings. The review then briefly explores nonpharmacological directions for intervention.

Night-time sleep duration and postpartum weight retention in primiparous women

Objectives

Approximately 75% of women weigh more at 1-year postpartum than pre-pregnancy. More than 47% retain >10 lbs at 1-year postpartum, which is associated with adverse health outcomes for mother and child. Disturbed sleep may contribute to risk of postpartum weight retention (PWR) as short sleep duration is associated with increased risk of obesity. Thus, we investigated whether night-time sleep duration is associated with risk for excessive PWR. We also explored night-time sleep duration and change in postpartum waist circumference.

Methods

This is an ancillary analysis from a prospective cohort study. Participants were healthy primiparous adults with a singleton birth. Excessive PWR at 1-year postpartum was defined as ≥7% of pre-pregnancy weight. Log-binomial and linear regression assessed associations between night-time sleep duration at 6 months postpartum and PWR at 1-year postpartum. Linear regression assessed the association between night-time sleep duration and change in postpartum waist circumference.

Results

Mean age of participants (N = 467) was 29.51 (SD ± 4.78) years. Night-time sleep duration by actigraphy or self-report was not associated with risk for excessive PWR (risk ratio 0.96, [95%CI 0.87-1.06]; risk ratio 0.95 [95%CI 0.83-1.07], respectively) or change in waist circumference.

Conclusion

Night-time sleep duration at 6 months postpartum was not associated with PWR at 1-year postpartum. Mixed findings among our results and previous research could be due to our focus on night-time sleep, and differences in sleep measurement methods and timeframes across studies. More comprehensively assessing sleep, including multiple sleep dimensions, may help advance our understanding of potential links between sleep and PWR.

Trial Registration

The parent study, Motherhood and Pelvic Health (MAP Study), is registered at https://clinicaltrials.gov/ct2/show/NCT02512016, NCT02512016.

Prevalence of Contributing Factors Leading to the Development of Insulin Resistance Among Male Medical Students at a Private College in Saudi Arabia

Background Insulin resistance can result from various genetic and lifestyle factors. Initially, symptoms of insulin resistance may not be readily noticeable, but as the condition progresses, individuals may start experiencing symptoms. This study aimed to investigate the factors contributing to the development of insulin resistance among medical students at a private college in Saudi Arabia. Methodology We conducted a cross-sectional study using a convenient non-probability sampling technique, with a sample size of 241 participants. We employed validated questionnaires to gather information on physical activity, sleep, dietary habits, and stress. Specifically, we used the International Physical Activity Questionnaire (IPAQ)-Short Form for assessing physical activity, the Single-Item Sleep Quality Scale (SQS) for evaluating sleep quality, the Healthy Eating Quiz (HEQ) to gauge dietary patterns, and the stress questionnaire designed by the International Stress Management Association (ISMA) to measure stress levels. Additionally, we collected anthropometric measurements, as well as systolic and diastolic blood pressure readings. We calculated prevalence using percentages and employed the chi-square test to analyze variables, with a significance level set at p-values <0.05. Results This study investigated risk factors associated with lifestyle, focusing on waist circumference as an indicator of insulin resistance. Our findings revealed that a majority of individuals with high waist circumference were physically inactive and more susceptible to stress, and this difference was statistically significant when compared to those with normal waist circumference. Additionally, we observed that sleep deprivation and poor nutrition were more prevalent among individuals with high waist circumference, although these differences were not statistically significant. Conclusions This study highlights a high prevalence of elevated waist circumference, indicating insulin resistance, among medical students. Furthermore, it underscores the significant presence of well-known risk factors associated with insulin resistance within this population of medical students.

Sleep duration and its association with adiposity markers in adolescence: a cross-sectional and longitudinal study

AIMS

Large studies linking adolescents' objectively measured sleep duration and adiposity markers are lacking. We characterized sleep duration and its cross-sectional and longitudinal associations with adiposity markers in adolescence.

METHODS AND RESULTS

Seven-day accelerometry was performed in a cohort of adolescents enrolled in the SI! Program for Secondary Schools trial in Spain at approximately ages 12 (1216 adolescents, 49.6% girls), 14 (1026 adolescents, 51.3% girls), and 16 (872 adolescents, 51.7% girls) years. Participants were classified as very short sleepers (VSS; <7 h), short sleepers (SS; 7-<8 h), or recommended-time sleepers (RTS; 8-10 h). Adjusted associations between sleep duration and adiposity markers were analysed using generalized linear and Poisson models. At ∼12 years, 33.7% of adolescents met sleep recommendations, and this percentage decreased with advancing age (22.6% at ∼14 and 18.7% at ∼16 years). Compared with RTS, overweight/obesity prevalence ratios at ∼12, 14, and 16 years among SS were 1.19 [95% confidence interval (CI): 1.09-1.30], 1.41 (95% CI: 1.34-1.48), and 0.99 (95% CI: 0.77-1.26) and among VSS were 1.30 (95% CI: 1.28-1.32), 1.93 (95% CI: 1.41-2.64), and 1.32 (95% CI: 1.26-1.37). Compared with adolescents who always met sleep recommendations, the prevalence of overweight/obesity was ∼5 times higher in those never meeting recommendations or meeting them only once. Similar trends were observed for the waist-to-height ratio (P = 0.010) and fat mass index (P = 0.024).

CONCLUSION

Most adolescents did not meet sleep recommendations. Shorter sleep duration was independently associated with unfavourable adiposity markers, and such adverse impact was cumulative. Health promotion programmes should emphasize the importance of good sleep habits.

The interplay between macronutrients and sleep: focus on circadian and homeostatic processes

Sleep disturbances are an emerging risk factor for metabolic diseases, for which the burden is particularly worrying worldwide. The importance of sleep for metabolic health is being increasingly recognized, and not only the amount of sleep plays an important role, but also its quality. In this review, we studied the evidence in the literature on macronutrients and their influence on sleep, focusing on the mechanisms that may lay behind this interaction. In particular, we focused on the effects of macronutrients on circadian and homeostatic processes of sleep in preclinical models, and reviewed the evidence of clinical studies in humans. Given the importance of sleep for health, and the role of circadian biology in healthy sleep, it is important to understand how macronutrients regulate circadian clocks and sleep homeostasis.

The association between sleep duration and detailed measures of obesity: A cross sectional analysis in the ADDITION-PRO study

Background

Sleep duration is associated with BMI and waist circumference. However, less is known about whether sleep duration affects different measurements of obesity differently.

Objective

To investigate the association between sleep duration and different measures of obesity.

Methods

In this cross-sectional analysis 1309, Danish, older adults (55% men) completed at least 3 days of wearing a combined accelerometer and heart rate-monitor for assessing sleep duration (hours/night) within self-reported usual bedtime. Participants underwent anthropometry and ultrasonography to assess BMI, waist circumference, visceral fat, subcutaneous fat, and fat percentage. Linear regression analyses examined the associations between sleep duration and obesity-related outcomes.

Results

Sleep duration was inversely associated with all obesity-related outcomes, except visceral-/subcutaneous-fat-ratio. After multivariate adjustment the magnitude of associations became stronger and statistically significant for all outcomes except visceral-/subcutaneous-fat-ratio, and subcutaneous fat in women. The associations with BMI and waist circumference demonstrated the strongest associations, when comparing standardized regression coefficients.

Conclusions

Shorter sleep duration were associated with higher obesity across all outcomes except visceral-/subcutaneous-fat-ratio. No specifically salient associations with local or central obesity were observed. Results suggest that poor sleep duration and obesity correlate, however, further research is needed to conclude on beneficial effects of sleep duration regarding health and weight loss.

Association of sleep duration and napping with stroke mortality in older Chinese: A 14-year prospective cohort study of the Guangzhou Biobank Cohort study

STUDY OBJECTIVE

Evidence regarding the association of short sleep duration and napping with stroke remains limited and controversial. We examined the association of sleep duration and napping with risk of stroke mortality in an older Chinese cohort.

METHODS

Sleep duration and daytime napping were assessed by face-to-face interview during 2003-2008. Information of causes of death until April 30, 2021 was collected via record linkage with the Death Registry. Cox regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Of 27,254 participants aged average 62.0 (standard deviation = 7.1) years, 818 stroke deaths occurred within 388,798 person-years (mean = 14.3 years) of follow-up. A U-shaped relation between sleep duration and risk of stroke mortality was observed. Participants with short (≤5 h/day) or long sleep duration (≥9 h/day) showed higher risks of total stroke mortality, with adjusted HRs (95% CIs) being 1.27 (1.01-1.59) and 1.37 (1.07-1.75), respectively. However, non-significant association of short or long sleep duration with hemorrhagic or ischemic stroke mortality was found. The associations of short and long sleep duration with total stroke mortality were more pronounced in those with hypertension (P for interaction with hypertension = 0.01), with HRs (95% CIs) being 1.37 (1.04-1.82) and 1.77 (1.33-2.36), respectively. No association between napping and risk of stroke mortality was found.

CONCLUSIONS

Both short and long sleep duration, but not daytime napping, were associated with higher risk of stroke mortality. Public health messages to encourage good sleep hygiene may be important, especially for people with hypertension.

Impact of a Weight-Loss Rehabilitation Program on Sleep Apnea Risk and Subjective Sleepiness in Patients with Overweight/Obesity: The DietSleep Study

Obstructive sleep apnea (OSA) is one of the most frequent chronic diseases, and comorbid obesity occurs in more than 60% of cases. Variations in body weight influence both OSA severity and OSA-related symptoms. We prospectively assessed the impact of a weight-loss program using the Berlin score to reflect OSA risk, and we also used the Epworth Sleepiness Scale (ESS) to assess daytime sleepiness. DietSleep was a prospective multicentric cohort study investigating OSA risk and daytime sleepiness before and after weight-loss intervention. One hundred and twenty-seven patients were included (initial OSA risk 36%), most of whom were women (85.8%) with a median body mass index (BMI) of 29.7 kg/m2, and the interquartile range was (27.6; 34). The diet-based weight-loss program induced a median decrease in BMI of 3.7 kg/m2 (−5; −2.9) (body weight~12.1% (−16.0; −8.8)) over a period of 171 days (114; 269). Changes in anthropometric values were similar regarding OSA risk after adjusting for initial values. Berlin scores significantly improved from 3 (1; 5) to 1 (0; 2), p < 0.01; the proportion of patients with a Berlin score ≥2 decreased from 36% to 7% after the intervention. The proportion of patients with ESS ≥11 decreased from 13% to 2%. These results confirm that a weight-loss program produces clinically relevant weight loss and a significant improvement in both OSA and subjective daytime sleepiness.

Shift Work and Obesity Risk-Are There Sex Differences?

PURPOSE OF REVIEW

Shift work is prevalent among the working population and is linked to an array of adverse health outcomes. This review summarizes current evidence on the relation between shift work and risk of obesity, with a particular emphasis on potential sex differences.

RECENT FINDINGS

Observational data strongly point towards an association between shift work and heightened risk of prevalent and incident obesity, and particularly abdominal obesity. Circadian misalignment and unhealthy lifestyle behaviors are the primary culprits mediating such association. As it pertains to sex differences in the impact of shift work on obesity, few studies have examined this aspect, and findings are conflicting. Shift work is an important risk factor for obesity, with likely multiple biological and behavioral mediators. However, whether there is a sex-dependent vulnerability to the obesogenic effects of shift work is unclear. This area presents opportunities for future research.

The Potential Role of Sleep in Promoting a Healthy Body Composition: Underlying Mechanisms Determining Muscle, Fat, and Bone Mass and Their Association with Sleep

Sleep plays an essential role in human life. While sleep is a state elicited by the brain, its vital role reaches beyond maintaining brain health. Unhealthy sleeping habits have been associated with increased risk for inflammation, obesity, or diabetes. Evidence is emerging that sleep guides processes playing an important role in promoting the regulation of endocrine function involved in tissue regeneration and tissue remodelling. Thereby, sleep presumably is a critical factor contributing to the balance of core body tissues: bone, fat, and muscle mass. Given the increasing prevalence of various chronic diseases and comorbidities due to unhealthy lifestyle choices, sleep could be a key target to promote a healthy body composition up until old age. Here, we review the potential role of sleep and its underlying brain oscillations in body core tissues turnover. Specifically, we discuss potential underlying mechanisms linking sleep to body composition, both during rest and under challenging conditions. Among other described pathways, we highlight the possible role of the growth hormone that was found to be involved in the homeostasis of all core body tissues and has been strongly linked to brain activity dominating deep sleep, the so-called slow waves. Finally, we formulate important questions to be addressed in future research on the effect of sleep on body composition and specifically emphasize the importance of intervention studies to move from correlative to causal evidence.

The links between sleep duration, obesity and type 2 diabetes mellitus

Global rates of obesity and type 2 diabetes mellitus (T2DM) are increasing globally concomitant with a rising prevalence of sleep deprivation and sleep disorders. Understanding the links between sleep, obesity and T2DM might offer an opportunity to develop better prevention and treatment strategies for these epidemics. Experimental studies have shown that sleep restriction is associated with changes in energy homeostasis, insulin resistance and β-cell function. Epidemiological cohort studies established short sleep duration as a risk factor for developing obesity and T2DM. In addition, small studies suggested that short sleep duration was associated with less weight loss following lifestyle interventions or bariatric surgery. In this article, we review the epidemiological evidence linking sleep duration to obesity and T2DM and plausible mechanisms. In addition, we review the impact of changes in sleep duration on obesity and T2DM.

Insomnia with physiological hyperarousal is associated with lower weight: a novel finding and its clinical implications

Previous studies on the association of insomnia with body mass index (BMI) have been controversial. Physiological hyperarousal, the key pathological mechanism of insomnia, may be an important reason for different findings. We explored whether insomnia with physiological hyperarousal measured by the multiple sleep latency test (MSLT) is associated with body-weight differences. A total of 185 normal sleepers and 440 insomniacs were included in this study. Insomnia was defined by standard diagnostic criteria with symptoms lasting ≥6 months. All subjects underwent one night of laboratory polysomnography followed by a standard MSLT. We used the median MSLT value (i.e., ≥14 min) to define physiological hyperarousal. BMI was based on measured height (cm) and weight (kg) during the subjects' sleep laboratory visit. BMI > 25 kg/m² was defined as overweight, while BMI < 18.5 kg/m² was defined as underweight. After controlling for confounders, the odds of lower weight rather than overweight were significantly increased among insomnia patients with increased MSLT: insomnia with MSLT 14-17 min and MSLT > 17 min increased the odds of lower weight by approximately 89% (OR = 1.89, 95% CI 1.00-4.85) and 273% (OR = 3.73, 95% CI 1.51-9.22) compared with normal sleepers, respectively. In contrast, insomnia in patients with MSLT 11-14 min and 8-11 min was not different from normal sleepers in terms of body weight. Insomnia associated with physiological hyperarousal, the most severe phenotype of chronic insomnia, is associated with higher odds of lower weight and underweight compared with normal sleepers. This is a novel finding consistent with previous physiologic data and has significant clinical implications.

Gender differences in self-reported sleep problems among older adults in six middle-income countries: a cross-sectional study

This study examines gender differences in sleep problems among older adults in India, China, Ghana, Mexico, Russia, and South Africa. We used data on 33,929 individuals (50+ years) from the WHO-SAGE. Results showed significant gender differences in the prevalence of sleep problems with the largest difference in Russia followed by India. Regression results showed higher odds of sleep problems among women in India, China, Russia, and South Africa. Age, low back pain, depression, and poor self-rated health were significantly associated with sleep problems. This research confirms significant gender differences in sleep problems among the older population in middle-income countries.

Sleep duration and anthropometric indices in an Iranian population: the Fasa PERSIAN cohort study

Recent decades have seen a dramatic rise in the prevalence of obesity. While genetic factors can influence obesity, environmental factors and lifestyle may play important roles as well. Sleep can be regarded as one of these factors. This study aimed to examine sleep duration, as a potential risk factor for obesity in an Iranian population. In this cross-sectional study, the Fasa PERSIAN cohort study data was used and 10,136 subjects aged 35-70 were entered. Anthropometrics indices have been measured and the total body fat percentage (BFP) was obtained by Bio-Impedance Analysis. Also, physical activity and dietary intake have been recorded. Sleep duration was obtained and individuals categorized into two groups of "< 8" and "≥ 8" h of sleep. The mean age and sleep duration of the participants were 48.63 ± 9.57 years and 6.92 ± 1.62 h in the total population, respectively. All of the anthropometric indices were significantly higher in the "< 8 h of sleep" group than in the "≥ 8 h of sleep" group. Regarding BFP and fat mass index (FMI) the same results was seen (p-value < 0.05). Body mass index (BMI), Waist and hip circumferences (WC, HC), and waist-to-height ratio (WHtR) were in a significant negative association with night time sleep (p-value < 0.001), while these associations with daytime napping were positive (p-value < 0.001). After multi-variable adjusting, BMI, WC, HC, WHtR, and wrist circumference showed significant negative associations with 24-h sleep duration (p-value < 0.05). This study established the association between nocturnal, daytime napping, 24-h sleep duration and obesity parameters. Daytime napping was positively associated with obesity parameters and short 24-h sleep duration was associated with higher risk of overweight/obesity. These results indicate that insufficient sleep can be a screening indicator for an unhealthy lifestyle and poor health outcomes.

Effects of sleep deprivation on sarcopenia and obesity: A narrative review of randomized controlled and crossover trials

Shortened and fragmented sleeping patterns occupying modern industrialized societies may promote metabolic disturbances accompanied by increased risk of weight gain and skeletal muscle degradation. Short-term sleep restriction may alter energy homeostasis by modifying dopamine brain receptor signaling, leading to hyperpalatable food consumption and risk of increased adiposity. Concomitantly, the metabolic damage caused by lower testosterone and higher cortisol levels may stimulate systemic inflammation, insulin resistance, and suppress pathways involved in muscle protein synthesis. These changes may lead to dysregulated energy balance and skeletal muscle metabolism, increasing the risk of sarcopenic obesity, an additional public health burden. Future trials controlling for food intake and exploring further the influence of sleep deprivation on anabolic and catabolic signaling, and gut peptide interaction with energy balance are warranted.

Associations Between Sleep Duration, Wake-Up Time, Bedtime, and Abdominal Obesity: Results From 9559 Chinese Children Aged 7-18 Years

OBJECTIVE

To investigate the associations of sleep duration, wake-up time, bedtime, and childhood abdominal obesity, and to test whether there is a weekday/weekend difference and the potential modifying role of sex.

METHODS

This cross-sectional study was based on the Students' Constitution and Health Survey and included 9559 students (4840 boys and 4719 girls) aged 7-18 years (7227 aged 7-12 years, 2332 aged 13-18 years). They were divided into two groups (control group and group with abdominal obesity). The physical measurements included children and youth body height, body weight, and waist circumference (WC). A parent-report questionnaire was used to collect the information about parent characteristics as well as lifestyle and sleep patterns (sleep duration, bedtime, and wake-up time of weekdays and weekends) of children and youth.

RESULTS

The prevalence of abdominal obesity was 30.57% and the percentages of sleep duration <9 hours/day, wake-up time before 07:00 am on weekdays and weekends, bedtime after 10:00 pm on weekends were significantly higher in the group with abdominal obesity. After adjusting for confounders, sleep duration <9 hours/day on weekends was inversely related to abdominal obesity in the overall subjects, regardless of their sex and age, while bedtime after 10:00 pm on weekends was inversely related to abdominal obesity only in the overall subjects, boys, and children aged 7-12 years. Logistic regression models in all subjects showed that shorter hours of weekends sleep duration were associated with greater risks of abdominal obesity, even after adjusting for all confounders, including wake-up time and bedtime. The adjusted odds ratios and 95% confidence intervals of abdominal obesity (with ≥10 hours/day as the reference group) for children with 9-10 hours/day, 8-9 hours/day, and <8 hours/day of weekend sleep duration were 1.23 (1.04-1.46), 1.59 (1.32-1.91) and 1.83 (1.42-2.36), respectively. Specifically, after stratification by sex and age, this phenomenon was only observed in boys and children aged 7-12 years.

CONCLUSIONS

Sleep duration and bedtime on weekends were independently associated with the risk of childhood abdominal obesity, particularly in boys and children aged 7-12 years.

Improving sleep disturbances in obesity by nutritional strategies: review of current evidence and practical guide

Over the past decades, there has been an increase in overweight and obesity worldwide rates in both in adult and children. In parallel, it has been reported a worsening of sleep duration and quality. Some studies have shown an association between obesity and sleep disturbances (SD) vice versa, subjects with obesity have a greater risk of SD. As well as SD influences diet, also food choices have been shown to influence various sleep-related variables, such as duration and quality. For this reason, nutrition could represent an important tool not only to lose weight but also to improve sleep in patients with obesity and sleep disturbances. Thus, the aim of this review is to provide an overview of the studies that assessed the association between obesity and SD and vice versa, highlighting possible nutritional advices as a tool to improve sleep in patients with obesity and sleep disturbances.

Chronotherapeutic efficacy of suvorexant on sleep quality and metabolic parameters in patients with type 2 diabetes and insomnia

AIMS

This study aimed to assess the chronotherapeutic efficacy of suvorexant on subjective sleep parameters and metabolic parameters in patients with type 2 diabetes and insomnia.

METHODS

Thirteen patients with type 2 diabetes who met the Pittsburg Sleep Quality index criteria for primary insomnia took suvorexant 20 mg/day (15 mg/day for ≥65 years) for 14 ± 2 weeks. The following parameters were assessed before and after the treatment: sleep diary for sleep duration and quality (i.e., sleep onset latency, waking after sleep onset, and sleep efficiency [sSE]), Insomnia Severity Index, clinical and biochemical data, continuous glucose monitoring (CGM), and validated self-administered questionnaire on food intake.

RESULTS

Suvorexant significantly improved sSE, abdominal circumference, and sucrose intake (all p < 0.05), but did not change HbA1c, CGM parameters, or body weight. Correlation analysis revealed that changes in sSE were associated with those in HbA1c and body weight (r = -0.61 and r = -0.66, respectively; both p < 0.05).

CONCLUSIONS

Suvorexant significantly improved sleep quality and obesity-associated parameters in patients with type 2 diabetes in 14 weeks. Improvements in sleep quality were associated with improvements in glycemic control. Sleep disorder treatment using suvorexant may provide metabolic benefits for patients with type 2 diabetes.

Does Sars-Cov-2 threaten our dreams? Effect of quarantine on sleep quality and body mass index

Background

COVID 19-related quarantine led to a sudden and radical lifestyle changes, in particular in eating habits. Objectives of the study were to investigate the effect of quarantine on sleep quality (SQ) and body mass index (BMI), and if change in SQ was related to working modalities.

Materials

We enrolled 121 adults (age 44.9 ± 13.3 years and 35.5% males). Anthropometric parameters, working modalities and physical activity were studied. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI) questionnaire. At baseline, the enrolled subjects were assessed in outpatient clinic and after 40 days of quarantine/lockdown by phone interview.

Results

Overall, 49.6% of the subjects were good sleepers (PSQI < 5) at the baseline and significantly decreased after quarantine (p < 0.001). In detail, sleep onset latency (p < 0.001), sleep efficiency (p = 0.03), sleep disturbances (p < 0.001), and daytime dysfunction (p < 0.001) significantly worsened. There was also a significant increase in BMI values in normal weight (p = 0.023), in subjects grade I (p = 0.027) and II obesity (p = 0.020). In all cohort, physical activity was significantly decreased (p = 0.004). However, analyzing the data according gender difference, males significantly decreased physical activity as well as females in which there was only a trend without reaching statistical significance (53.5% vs 25.6%; p = 0.015 and 50.0% vs 35.9%, p = 0.106; in males and females, respectively). In addition, smart working activity resulted in a significant worsening of SQ, particularly in males (p < 0.001).

Conclusions

Quarantine was associated to a worsening of SQ, particularly in males doing smart working, and to an increase in BMI values.

Association between sleep duration and differences between weekday and weekend sleep with body mass index & waist circumference among Black women in Sistertalk II

OBJECTIVES

Examine associations between sleep duration and differences between weekday and weekend sleep with body mass index and waist circumference in a sample of high-risk Black women from the SisterTalk II study.

DESIGN

Cross-sectional analysis of baseline data from an intervention study targeting dietary and physical activity behaviors.

SETTING

Women were recruited from the Providence, RI, USA, area.

PARTICIPANTS

The sample includes 569 middle-aged Black women who were hypertensive or at risk for hypertension.

MEASUREMENTS

Participants self-reported their weekday and weekend sleep duration. Body mass index (BMI) and waist circumference (WC) were objectively measured. Associations between the sleep and anthropometric measures were examined using analysis of variance and multivariable regression models controlling for birthplace, educational attainment, employment status, and annual household income.

RESULTS

25.5% of the sample were very short sleepers (≤6 hrs), 28.8% short sleepers (≥6 to <7 hrs), 40.4% recommended sleepers (≥7 to ≤9 hrs), and 5.3% long sleepers (>9 hrs); 70.7% had a consistent sleep duration (≤2-hour difference between weekday and weekend sleep duration), 21.6% were classified as "weekend snoozers" (>2-hours more sleep on weekends), and 7.7% were classified as "weekend warriors" (>2-hours less sleep on weekends). Compared to recommended sleepers, very short sleepers and long sleepers had significantly greater BMIs, while long sleepers had significantly larger WCs. Being a weekend snoozer was also associated with increased BMI and WC.

CONCLUSIONS

In this sample of high-risk Black women, sleep duration and differences between weekday and weekend sleep were independently associated with excess weight and abdominal obesity.

An Overview on the Associations between Health Behaviors and Brain Health in Children and Adolescents with Special Reference to Diet Quality

Unhealthy diet has been associated with overweight, obesity, increased cardiometabolic risk, and recently, to impaired cognition and academic performance. The aim of this review is to provide an overview of the associations between health behaviors and cognition and academic achievement in children and adolescents under 18 years of age with a special reference to diet quality. Dietary patterns with a low consumption of fish, fruits, and vegetables, and high in fast food, sausages, and soft drinks have been linked to poor cognition and academic achievement. The studies on the associations between the high intake of saturated fat and red meat and low intake of fiber and high-fiber grain products with cognition are limited. The available evidence and physiological mechanisms suggest that diet may have direct, indirect, and synergistic effects on brain and cognition with physical activity, sedentary behaviors, cardiometabolic health, and sleep, but the associations have been modest. Therefore, integrating a healthy diet, physically active lifestyle, and adequate sleep may provide optimal circumstances for brain development and learning. We conclude that most of the existing literature is contained in cross-sectional studies, which therefore highlights the need for longitudinal and intervention studies on the effects of diet, physical activity, sedentary behavior, and sleep on cognition and academic performance.

Association of Sleep Duration with Weight Gain and General and Central Obesity Risk in Chinese Adults: A Prospective Study

OBJECTIVE

Evidence on the association between sleep duration and obesity among adults is inconsistent. Prospective studies investigating the association in Chinese adults have been limited. This study aims to prospectively evaluate sleep duration in relation to subsequent weight gain and general and central obesity risk among Chinese adults.

METHODS

A total of 21,958 participants aged 30 to 79 years reported their daily sleep duration. Obesity indicators were objectively measured; then significant weight gain (≥ 5 kg) and general and central obesity were modeled as the outcome. Logistic regression models were used to estimate odds ratios and 95% CIs.

RESULTS

Average sleep duration was 7.5 hours at baseline. During 8.0 ± 0.8 years of follow-up, participants who reported sleeping ≤ 6 hours had higher risk for significant weight gain than those who slept 7 hours (multivariable-adjusted odds ratio: 1.13; 95% CI: 1.02-1.29). The association was stronger among those who were physically inactive at baseline (P = 0.04 for interaction). Short sleep duration was also associated with subsequent incident central obesity, with odds ratio of 1.13 (95% CI: 1.00-1.28), but not with incident general obesity (P = 0.31).

CONCLUSIONS

Compared with those who slept 7 hours per day, short sleepers had an increased risk of significant weight gain and central obesity.

High sleep variability predicts a blunted weight loss response and short sleep duration a reduced decrease in waist circumference in the PREDIMED-Plus Trial

BACKGROUND

Whether short sleep duration or high sleep variability may predict less weight loss and reduction in measures of adiposity in response to lifestyle interventions is unknown. The aim of this study was to compare the 12-month changes in weight and adiposity measures between those participants with short or adequate sleep duration and those with low or high sleep variability (intra-subject standard deviation of the sleep duration) in PREvención con DIeta MEDiterránea (PREDIMED)-Plus, a primary prevention trial based on lifestyle intervention programs.

METHODS

Prospective analysis of 1986 community-dwelling subjects (mean age 65 years, 47% females) with overweight/obesity and metabolic syndrome from the PREDIMED-Plus trial was conducted. Accelerometry-derived sleep duration and sleep variability and changes in average weight, body mass index (BMI), and waist circumference (WC) attained after 12-month interventions were analyzed.

RESULTS

The adjusted difference in 12-month changes in weight and BMI in participants in the third tertile of sleep variability was 0.5 kg (95% CI 0.1 to 0.9; p = 0.021) and 0.2 kg/m2 (0.04 to 0.4; p = 0.015), respectively, as compared with participants in the first tertile. The adjusted difference in 12-month changes from baseline in WC was -0.8 cm (-1.5 to -0.01; p = 0.048) in participants sleeping <6 h, compared with those sleeping between 7 and 9 h.

CONCLUSIONS

Our findings suggest that the less variability in sleep duration or an adequate sleep duration the greater the success of the lifestyle interventions in adiposity.

Dietary Patterns, Exercise, and the Metabolic Syndrome Among Young People in Urban Pakistan (Lahore)

Background: Increasing urbanization, mechanization, and rural-to-urban migration has led to deranged sleeping patterns, surplus energy intake, and sedentary lifestyles in South Asian young people. This shift poses an insidious health risk for the development of metabolic syndrome (MetS). Early detection is needed because in the South Asian population, this syndrome carries an increased risk of comorbidities compared to people without the syndrome. This study was designed to elucidate the prevalence of MetS and its risk factors in young people in urban areas of Pakistan. Methods: A cross-sectional study was conducted in four undergraduate institutions in Lahore, Pakistan. Five hundred and nine young people participated, and each provided their informed consent for the collection of data on their demographic, physical, and biochemical characteristics along with information on their dietary, sleep, and physical activity habits. Results: Most participants reported consuming greater-than-recommended amounts of protein and smaller-than-recommended amounts of vegetables and fruits. The International Diabetes Federation criteria for MetS were fulfilled by 6.1% of the students. Hypertension (67.7%) and hypo-HDL-emia (64.5%) were the most common risk factors. More than 50% of the respondents slept fewer hours per day than recommended, and 33% had a sedentary lifestyle. Men, participants with a family history of metabolic illness and those with low physical activity levels had higher odds of a positive result on screening for MetS. Conclusions: The early detection of MetS and early identification of probable risk factors may make beneficial contributions to both public health and clinical interventions directed at high-risk individuals. Establishing and using cutoff values for modified waist circumference and specific body mass index in Asian populations may aid in early detection.

Fat Intake and Stress Modify Sleep Duration Effects on Abdominal Obesity

Though the association between sleep duration and obesity has been generally acknowledged, there is little information about the mechanisms behind this association. The purpose of this study was to examine the effect of the fat intake and stress variables on the association between sleep duration and abdominal obesity. Data for 13,686 subjects aged ≥ 20 years from the 2013–2017 Korea National Health and Nutrition Examination Survey were used, and hierarchical and stratified logistic regression analyses were employed. In the hierarchical logistic regression analyses, fat intake and stress did not change the significance or the size of the sleep effects upon abdominal obesity. These results suggest that sleep duration does not affect abdominal obesity through fat intake or stress variables. In addition, fat intake and stress are not mediators of the sleep duration variable. However, subjects with different levels of fat intake and stress showed different associations between sleep duration and abdominal obesity. Subjects who were in the lowest or highest group of fat intake as well as self-reported stress level showed a weaker relationship between sleep duration and abdominal obesity, compared with the other groups. In conclusion, fat intake and stress modify the effects of sleep duration on abdominal obesity according to the stratified regression results.

Associations between nocturnal sleep duration, midday nap duration and body composition among adults in Southwest China

Objective

We aim to explore the relationship between nocturnal sleep duration (NSD) and midday nap duration (MND) with body composition among Southwest Chinese adults.

Methods

Data on sleep duration of 3145 adults in Southwest China (59.4% women) were obtained between 2014 and 2015 through questionnaires. Height, weight, and waist circumference (WC) were measured to calculate body composition (body mass index (BMI), percentage of body fat (%BF), and fat mass index (FMI)). Linear regression models were used to assess gender-specific associations between NSD and body composition. The relationship between MND with the odds of overweight and central obesity has been evaluated by logistic regression models.

Results

NSD has the inverse relation with males’ BMI, WC, %BF and FMI after adjusting for all covariates (all P <0.0007), exclusive of females’ (all P >0.4). After adjustment for potential confounders, compared to the subjects in the no midday nap group, the subjects who napped 0.1–1 hour were independently associated with a less prevalence of overweight in both women (OR: 0.72, 95%CI: 0.55–0.95) and men (OR: 0.71, 95%CI: 0.52–0.98). MND was not associated with central obesity.

Conclusions

Among Southwest Chinese adults, lower NSD might be related to higher BMI, WC, %BF and FMI among men. Additionally, MND is associated with overweight in adults.

Sleep duration and risk of all-cause mortality: a systematic review and meta-analysis

AIMS

To determine the association between the sleep duration and the risk of all-cause mortality in adults.

METHODS

A search strategy was conducted in the MEDLINE, CENTRAL, EMBASE and LILACS databases. Searches were also conducted in other databases and unpublished literature. Cohort studies were included without language, time or setting restrictions. The risk of bias was evaluated with a modified Cochrane Collaboration's tool. An analysis of random effects was conducted. The primary outcome was all-cause mortality. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned comparisons were 7-9 h of sleep v. <7 h and the same reference v. >9 h.

RESULTS

Thirty-nine studies were included in our qualitative analysis, regarding the quantitative analysis, 19 studies were included in <7 v. 7-9 h analysis, and 18 studies in the >9 v. 7-9 h. A low risk of bias was shown for most of the study items. The overall RD for all-cause mortality was 0.09 (95% CI 0.07-0.11) favouring the >9 h group compared with our reference. In contrast, no differences were found between the <7 h and the reference sleep duration groups (RD 0.00, 95% CI 0.00-0.01).

CONCLUSION

We found a probable association of long sleep duration and higher mortality; however, it could reflect an underlying systemic or neurological disease that cause sleep fragmentation, deterioration in quality and micro-awakenings.

Maternal Sleep in Pregnancy and Postpartum Part I: Mental, Physical, and Interpersonal Consequences

PURPOSE OF REVIEW

Sleep is a critical restorative behavior which occupies approximately one third of people's lives. Extensive data link sleep health with disease and mortality risk in the general population. During pregnancy and following childbirth, unique factors contribute to overall sleep health. In addition, there are unique implications of poor sleep during these time periods.

RECENT FINDINGS

Poor maternal sleep may contribute to risk for adverse birth outcomes as well as poor maternal physical and mental health in pregnancy, postpartum, and longer term during childrearing. Moreover, the extent to which notable racial disparities in sleep contribute to disparities in adverse perinatal health outcomes remains to be fully explicated. Part I of this two-part review details these implications of poor sleep for mental health, physical health outcomes, and relationship functioning, while Part II delves into biological mechanisms as well as treatment approaches.

Association between insomnia and personality traits among Japanese patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

Insomnia is associated with type 2 diabetes mellitus, and results in a low quality of life. There are several known relationships between insomnia and personality. Thus, we clarified the association between some personality traits and insomnia among Japanese type 2 diabetes mellitus patients.

MATERIALS AND METHODS

The participants were 504 type 2 diabetes mellitus patients (mean age 63.9 ± 12.5 years). Sleep disturbance and personality traits were evaluated using the Pittsburgh Sleep Quality Index-Japanese version and the Ten-Item Personality Inventory Japanese version, respectively. Lifestyle factors, glycated hemoglobin levels and depressive status of the patients were also included in the analyses.

RESULTS

Among the 504 participants with type 2 diabetes mellitus, 154 (30.6%) showed probable insomnia. After adjustment for confounders, being female, living alone, high body mass index and "high neuroticism" were found to be significantly correlated with current insomnia. No other relationships between insomnia and glycated hemoglobin or lifestyle factors, such as smoking, drinking alcohol or exercise frequency, were found.

CONCLUSIONS

The prevalence of insomnia in individuals with type 2 diabetes mellitus was high, and the risk factors included some personality factors. Future prospective studies are required to confirm the therapeutic effects of behavioral interventions for insomnia in patients with type 2 diabetes mellitus.

Objectively measured sleep and body mass index: a prospective bidirectional study in middle-aged and older adults

BACKGROUND

In recent years, short sleep has been increasingly recognized as a risk factor for obesity. However, current evidence has so far been limited to cross-sectional studies or longitudinal studies using self-reported sleep. Therefore, we explored the directionality of the association between objectively measured sleep and body mass index (BMI).

METHODS

The study consists of 1031 participants from the general population (52% women, 45-91 years at baseline). Sleep, BMI and waist circumference (WC) were measured twice across a follow-up of six years. BMI and WC were measured at the research center. Total sleep time (TST, hrs), sleep onset latency (SOL, min), sleep efficiency (SE, %) and wake after sleep onset (WASO, min) were estimated by a wrist-worn actigraph. In addition, cross-sectional and longitudinal associations in both directions were explored.

RESULTS

An hour shorter TST was cross-sectionally associated with approximately 0.5 kg/m² higher BMI. Longitudinally, longer TST and higher SE were associated with lower BMI (β_TST = -0.75, 95% CI: -1.08, -0.42; β_SE = -0.04, 95% CI: -0.08, -0.01). Conversely, one kg/m² higher BMI was prospectively associated with 0.02 h shorter TST (95% CI: -0.03, -0.01), and this association was more pronounced over time. Results from analyses with WC were in line with those of BMI.

CONCLUSIONS

This is the first study to explore bidirectionality in the association between objectively measured sleep and BMI in a large population of middle-aged and older adults. Indices of poor sleep were associated with higher and less stable BMI across time. Conversely, a high BMI was associated with a decrease in sleep duration. This confirms that the relation between sleep and body size is bidirectional, and changes in either sleep or BMI are likely to co-occur with changes in health through multiple pathways.

Sleep and obesity: the mediating role of health behaviors among African Americans

OBJECTIVES

To examine the role of health behaviors (eg, physical activity, sedentary behaviors, and diet) in the relationship between sleep (ie, duration and quality) and BMI among African American adults.

DESIGN

A cross-sectional self-report questionnaire included questions related to health and health-related behaviors.

SETTING

This study was based on data from the CHURCH study, which aimed to address cancer health disparities among church-going African Americans in Houston, TX.

PARTICIPANTS

African American adults were recruited from three large community churches. The sample included a total of 1837 participants (75.2% female; mean age 48.2 ± 13.7y; mean BMI 32.0 ± 7.5 kg/m²).

MEASUREMENTS

Linear regression models and path analyses controlling for demographic characteristics and depression estimated the associations between sleep and BMI as well as the mediating roles of health behaviors.

RESULTS

The average self-reported sleep duration was 6.2 ± 1.5 h/night with 61%, 35.8%, and 1.6% reporting short (≤6 h/night), normal (7-9 h/night), and long sleep (≥10 h/night), respectively. Short sleep was related to greater BMI (b = 1.37, SE = 0.38, P = .01), and the relationship was mediated by sedentary behaviors (est. = 0.08, SE = 0.04, 95% CI: 0.02, 0.17).

CONCLUSIONS

Short sleep and poor quality sleep was related to poor diet and physical activity-related health behaviors, and BMI. The link between sleep and obesity is, in part, due to energy imbalance from increased sedentary behavior.

Sleep Deprivation Selectively Upregulates an Amygdala-Hypothalamic Circuit Involved in Food Reward

Sleep loss is associated with increased obesity risk, as demonstrated by correlations between sleep duration and change in body mass index or body fat percentage. Whereas previous studies linked this weight gain to disturbed endocrine parameters after sleep deprivation or restriction, neuroimaging studies revealed upregulated neural processing of food rewards after sleep loss in reward-processing areas such as the anterior cingulate cortex, ventral striatum, and insula. To address this ongoing debate between hormonal versus hedonic factors underlying sleep-loss-associated weight gain, we rigorously tested the association between sleep deprivation and food cue processing using high-resolution fMRI and assessment of hormones. After taking blood samples from 32 lean, healthy, human male participants, they underwent fMRI while performing a neuroeconomic, value-based decision-making task with snack food and trinket rewards following a full night of habitual sleep and a night of sleep deprivation in a repeated-measures crossover design. We found that des-acyl ghrelin concentrations were increased after sleep deprivation compared with habitual sleep. Despite similar hunger ratings due to fasting in both conditions, participants were willing to spend more money on food items only after sleep deprivation. Furthermore, fMRI data paralleled this behavioral finding, revealing a food-reward-specific upregulation of hypothalamic valuation signals and amygdala-hypothalamic coupling after a single night of sleep deprivation. Behavioral and fMRI results were not significantly correlated with changes in acyl, des-acyl, or total ghrelin concentrations. Our results suggest that increased food valuation after sleep loss might be due to hedonic rather than hormonal mechanisms.SIGNIFICANCE STATEMENT Epidemiological studies suggest an association between overweight and reduced nocturnal sleep, but the relative contributions of hedonic and hormonal factors to overeating after sleep loss are a matter of ongoing controversy. Here, we tested the association between sleep deprivation and food cue processing in a repeated-measures crossover design using fMRI. We found that willingness to pay increased for food items only after sleep deprivation. fMRI data paralleled this behavioral finding, revealing a food-reward-specific upregulation of hypothalamic valuation signals and amygdala-hypothalamic coupling after a single night of sleep deprivation. However, there was no evidence for hormonal modulations of behavioral or fMRI findings. Our results suggest that increased food valuation after sleep loss is due to hedonic rather than hormonal mechanisms.