Examining the pathways linking chronic sleep restriction to obesity

Association of Insomnia, Sleep Quality, and Sleep Duration With Risk of Physical Frailty in Middle-aged and Older People With HIV

Background

Frailty is one of the major concerns among aging people with HIV (PWH). Evidence regarding the association between sleep disorders and physical frailty in PWH is limited.

Methods

PWH and HIV-negative individuals aged ≥40 years were included and frequency-matched in a 1:2 ratio by sex and age. Logistic regression models were used to estimate the odds ratios (ORs) and 95% CIs of the association between sleep disorders and physical frailty, and restricted cubic splines were used to describe the dose-response association. The contribution of depression to the association was estimated by mediation analysis.

Results

A total of 1526 PWH and 3052 HIV-negative individuals were included. Logistic regression indicated that insomnia (OR, 3.05; 95% CI, 1.63-5.72) and poor sleep quality (OR, 2.32; 95% CI, 1.21-4.45) were significantly associated with physical frailty in middle-aged and older PWH, especially in those with current CD4+ T-cell counts <350 cells/µL, but not in HIV-negative participants. A U-shaped and J-shaped dose-response relation between sleep duration and physical frailty was observed in PWH and HIV-negative participants, respectively. Shorter and longer sleep duration was associated with an increased risk of physical frailty in PWH. However, in HIV-negative participants, only longer sleep duration was associated with physical frailty. Mediation analysis revealed that depression mediated the relation between sleep disorders and frailty among PWH.

Conclusions

Sleep disorders including insomnia, poor sleep quality, and short and long sleep duration were significantly associated with physical frailty among middle-aged and older PWH. Depression may play a mediating role in the sleep-frailty association.

Temporal relationship between sleep duration and obesity among Chinese Han people and ethnic minorities

BACKGROUND

No studies have assessed the association between sleep duration and obesity in Chinese ethnic minorities. Whether the relationship between sleep duration and obesity is different between Chinese Han people and Chinese ethnic minorities remains unclear. The study aimed to explore the relationship between sleep duration and obesity among Chinese Han people and Chinese ethnic minorities.

METHODS

We applied data from the Guizhou Population Health Cohort Study (GPHCS), which 9,280 participants were recruited in the baseline survey from 2010 to 2012, and 8,163 completed the follow-up survey from 2016 to 2020. A total of 5,096 participants (3,188 Han Chinese and 1,908 ethnic minorities) were included in the ultimate analysis. Information on sleep duration (total 24-hour sleep time), body mass index (BMI), and waist circumference (WC) was collected at the baseline and follow-up survey, respectively. Cross-lagged panel analyses were conducted to explore the temporal relationship between sleep duration and obesity for Han people and ethnic minorities.

RESULTS

For Han people, the results from cross-lagged panel analyses indicated that baseline sleep duration was significantly associated with follow-up BMI (β_BMI = -0.041, 95% CI_BMI: -0.072 ~ -0.009) and follow-up WC (β_WC = -0.070, 95%CI_WC: -0.103 ~ -0.038), but baseline BMI (β_BMI = -0.016, 95% CI_BMI: -0.050 ~ 0.018) and baseline WC (β_WC = -0.019, 95% CI_WC: -0.053 ~ 0.016) were not associated with follow-up sleep duration. In addition, the relationship between baseline sleep duration and follow-up BMI was gender-specific and significant only in the Han people female (β_BMI = -0.047, 95% CI_BMI: -0.090 ~ -0.003) but not in the Han people male (β_BMI = -0.029, 95% CI_BMI: -0.075 ~ 0.016). For ethnic minorities, the results indicated that there was no relationship between sleep duration and obesity at all, either from sleep duration to obesity (β_BMI = 0.028, 95%CI_BMI: -0.012 ~ 0.068; β_WC = 0.020, 95%CI_WC: -0.022 ~ 0.062), or from obesity to sleep duration (β_BMI = -0.022, 95%CI_BMI: -0.067 ~ 0.022; β_WC = -0.042, 95%CI_WC: -0.087 ~ 0.003).

CONCLUSION

The relationship pattern between sleep duration and obesity across Han people and ethnic minorities is different. Future sleep-aimed overweight and obesity intervention should be conducted according to population characteristics.

Association of sleep duration and sleep quality with overweight/obesity among adolescents of Bangladesh: a multilevel analysis

Background

Sleep deprivation is widely recognized as a potential contributor to childhood obesity. However, few studies have addressed this issue in low-income settings. The aim of this study was to determine the association of both sleep duration and sleep quality with overweight/obesity among adolescents of Bangladesh.

Methods

A cross-sectional study was conducted in four randomly selected schools in Gazipur, Bangladesh, from May to August 2019. Using a self-administered semi-structured questionnaire, data on sleep duration and sleep quality were collected from 1,044 adolescents between 13 and 17 years of age. The body mass indices of the study participants were evaluated using their objectively-assessed anthropometric measurements (weight and height). Multilevel logistic regression was used for data analysis.

Results

The prevalence of underweight, overweight and obesity in adolescents in this study were 14.9, 18 and 7.1%, respectively. More than 15% of the students reported sleep disturbance and poor sleep quality. After adjusting for confounders, reduced (<7 h/day) total sleep duration (OR=1.73, 95% CI=1.21-2.47), weekend sleep duration (OR=1.46, 95% CI=1.00-2.12), and night sleep duration (OR=1.55, 95% CI=1.06-2.28) were found to be significantly associated with overweight or obesity in Bangladeshi adolescents. Similarly, significant positive associations were evident between short duration of total sleep (OR=0.33, 95% CI=0.20-0.54), weekday sleep (OR=0.55, 95% CI=0.35-0.84), weekend sleep (OR=0.53, 95% CI=0.31-0.89), and night sleep (OR=0.56, 95% CI=0.36-0.87), and underweight in study participants. Adolescents with short sleep duration were found less likely to be underweight and more likely to be overweight/obese.

Conclusions

Study findings denoted short sleep duration to be associated with overweight/obesity and underweight among adolescents of Bangladesh. Adequate sleep may therefore serve as an effective obesity prevention strategy in the growing stages.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12774-0.

Disruption of the circadian rhythms and its relationship with pediatric obesity

The circadian clock system is an evolutionarily conserved system by which organisms adapt their metabolic activities to environmental inputs, including nutrient availability. The disruption of this system has been pathogenically linked to the disintegration of metabolic homeostasis, leading to the development of metabolic complications, including obesity. Lifestyle factors that disrupt this system have been found to be associated with the development of metabolic disorder, which is most evidenced by the finding that shift workers are at an increased risk of developing various disorders, such as obesity and obesity-related complications. Lifestyle factors that contribute to a misalignment between the internal clock system and environmental rhythms have also been identified in children. A short sleep duration and skipping breakfast are prevalent in children and there is mounting evidence that these factors are associated with an increased risk of pediatric obesity; however, the underlying mechanisms have not yet been elucidated in detail. Our current understanding of the impact of lifestyle factors that cause a misalignment between the internal clock system and environmental rhythms on the development of pediatric obesity is summarized herein, with a discussion of potential mechanistic factors.

Obesity and sleep disturbances: The "chicken or the egg" question

Obesity and sleep disturbances are common conditions in modern societies and accumulating evidence support a close bidirectional causal relationship between these two conditions. Indeed, from one side sleep loss seems to affect energy intake and expenditure through its direct effects on hormone-mediated sensations of satiety and hunger and through the influence on hedonic and psychological aspects of food consumption. Sleep deprived patients have been shown to experiment excessive daytime sleepiness, fatigue, and tiredness that, in a vicious circle, enhances physical inactivity and weight gain. On the other side, obesity is a well-known risk factor for several sleep disorders. This narrative review will discuss the main pathophysiological mechanisms that link sleep loss to obesity and metabolic syndrome with particular attention to the three most common sleep disorders (insomnia, obstructive sleep apnoea syndrome, restless leg syndrome).

Association of self-reported sleep disturbances with ideal cardiovascular health in Brazilian adults: A cross-sectional population-based study

OBJECTIVE

To examine the association between sleep disturbances and cardiovascular health in Brazilian adults.

METHODS

We analyzed cross-sectional data from a nationally representative sample of 36,480 Brazilian adults ages 18 and over. Multivariate Poisson regression models were used to assess the association between sleep disturbances (difficulty falling asleep, frequent interruptions in sleep, or sleeping more than usual) and Life's Simple 7 (LS7) cardiovascular health (CVH) scores through consideration of four behaviors (smoking, physical activity, body mass index, and diet) and three biological factors (hypercholesterolemia, hypertension, and diabetes).

RESULTS

Adults with no sleep disturbances had better CVH, with higher mean LS7 CVH scores (4.2, 95% confidence interval [CI]: 4.1; 4.2) when compared to those experiencing some level of sleep disturbance within a 2-week timespan (3.8, 95% CI: 3.7; 3.8). Specifically, compared to those with no sleep disturbance, adults reporting sleep disturbances for half of the weekdays had significantly lower LS7 CVH mean scores (β = -0.02, 95% CI: -0.04; 0.01). Adults who had disturbances more than half of the weekdays had even lower scores (β = -0.06, 95% CI: -0.09; -0.02), followed by those who reported disturbances almost every day (β = -0.08, 95% CI: -0.11; -0.04), even after adjusting for age, sex, education status, depressive symptoms, and night shift work.

CONCLUSION

Brazilian adults with sleep disturbances are less likely to achieve ideal CVH. Given that sleep disturbances seem to be increasingly common in Brazil, recent gains in CVH mortality may be affected.

Exploring Relationships of Sleep Duration with Eating and Physical Activity Behaviors among Canadian University Students

BACKGROUND

Students pursuing postsecondary education are a population described as vulnerable for sleep problems, poor dietary habits, weight gain, and reduced physical activity. The primary goal of this study was to examine relationships of sleep behaviors with eating and physical activity behaviors in a sample of undergraduate health sciences students.

METHODS

Using a cross-sectional design, undergraduate health sciences students in a small Canadian university were recruited to complete an on-line questionnaire about their sleep, eating, and physical activity behaviors using valid and reliable instruments. Key sociodemographic characteristics and self-reported height and weight data were also captured.

RESULTS

The participants (n = 245) were on average 23 years of age, female (86%), and the majority were full-time students (92%). The mean BMI was within a healthy range (mean 24.58 SD 5.55) with the majority reporting low physical activity levels (65%). Despite self-reports of very or fairly good (65%) sleep quality in the past month, the mean global sleep scores (scores > 5, mean 7.4, SD 3.3) indicated poor overall sleep quality. Poorer sleep quality was associated with higher BMIs (r = 0.265, p < 0.001).

CONCLUSIONS

The findings highlight the need to expand the scope of on-campus wellness programs to promote healthy sleep habits in a vulnerable university population.

Association of sleep duration and snack consumption in children and adolescents: The CASPIAN-V study

OBJECTIVES

The relationship between sleep deprivation and the risk of overweight and obesity is somewhat known in children and adolescents. This study aimed to investigate the relationship between sleep duration and eating snacks in a national sample of children and adolescents aged 6-18 years old.

METHODS

This cross-sectional study was carried out on the data of the fifth survey of the national school-based surveillance system entitled the "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable Disease" (CASPIAN-V) study. Short sleeping duration was defined 10 hr per day for children under 10 years and 9 hr per day for children ≥ 10 years. To assess food habits, the consumption frequency of some food groups including sweets, salty snacks, carbonated beverages, diet soft drinks, soft beer, fresh fruits, dried fruits, fresh juices, vegetables, packed juices, dairy products (milk, yogurt, and cheese), fast foods, tea, sugar along with tea, and coffee was asked using Likert scale ( never, rarely, weekly, and daily).

RESULTS

In multivariate model, short sleep versus long sleep in students was associated with increased chance of eating salty snacks (OR = 1.49 [95% CI: 1.38-1.61]; p = .001), soft drinks (OR = 1.12 [95% CI: 1.04-1.20]; p = .002), fast foods (OR = 1.66 [95% CI: 1.54-1.79]; p < .001), tea (OR = 1.49 [95% CI: 1.39-1.61]; p < .001), and tea with sugar (OR = 1.13 [95% CI: 1.05-1.22]; p < .001). In addition, short sleep in students was associated with a decreased odds of daily intake of soft drinks without sugars (OR = 0.64 [95% CI: 0.58-0.70]; p < .001), soft beer (OR = 0.92 [95% CI: 0.85-0.99]; p < .001), fresh fruit (OR = 0.83 [95% CI: 0.76-0.90]; p < .001), dried fruit (OR = 0.43 [95% CI: 0.39-0.46]; p < .001), fresh fruit juice (OR = 0.66 [95% CI: 0.62-0.72]; p < .001), packed juice (OR = 0.91 [95% CI: 0.84-0.98]; p < .009), milk (OR = 0.51 [95% CI: 0.47-0.55]; p < .001), yogurt (OR = 0.86 [95% CI: 0.79-0.93]; p ≤ .001), and coffee (OR = 0.82 [95% CI: 0.76-0.89]; p ≤ .001).

CONCLUSIONS

The findings of this study indicate a significant relationship between sleep duration and unhealthy food habits. Therefore, increasing awareness of families in this area may reduce obesity and its complications.

Sleep-inducing effect of Passiflora incarnata L. extract by single and repeated oral administration in rodent animals

Social cost of insomnia in modern society is gradually increasing. Due to various social phenomena and lifestyles that take away the opportunity of good quality of sleep, problems of insomnia cannot be easily figured out. Prescription of sleeping pills for insomnia patients can cause other inconveniences due to their side effects beyond their intended purposes. On the other hand, Passiflora incarnata L. (PI) has been widely used in South America for several centuries, showing effectiveness for sleep, sedation, anxiety, and so on in the civilian population. However, reports on the treatment efficacy of this herbal medicinal plant for insomnia patients through standardization as a sleeping agent have been very rare. Therefore, we obtained leaves and fruits of PI (8:2 by weight) as powder to prepare an extract. It was then applied to C6 rat glioma cells to quantitate mRNA expression levels of GABA receptors. Its sleep-inducing effect was investigated using experimental animals. PI extract (6 μg/ml) significantly decreased GABA receptors at 6 hr after treatment. Immobility time and palpebral closing time were significantly increased after single (500 mg/kg) or repeated (250 mg/kg) oral administration. In addition, blood melatonin levels were significantly increased in PI extract-treated animals after both single and repeated administrations. These results were confirmed through several repeated experiments. Taken together, these results confirmed that PI extract had significant sleep-inducing effects in cells and animals, suggesting that PI extract might have potential for treating human insomnia.

Sleep Duration and Obesity in Children and Adolescents

Increased rates of obesity internationally have drawn significant attention. In particular, researchers and practitioners are seeking new information about risk factors for obesity that could be areas for preventive interventions. Given that obesity rates in children and adolescents are increasing worldwide, particular attention to child and adolescent obesity is needed. A large, and growing, body of research indicates that inadequate sleep duration is linked to obesity. The current article reviews the extant literature concerning sleep duration and obesity in children and adolescents by reviewing current theories of obesity as well as available literature specifically evaluating the relationship of obesity and sleep in children and adolescents, including epidemiologic, experimental and intervention research. Overall, our literature review concludes that the relationship between shortened sleep and increased risk for obesity has research support internationally, including in the few Canadian articles available that are discussed in our review.

Upregulation of Foreign Body Response in Obese Mice

OBJECTIVE

Obesity is a highly prevalent multifactorial metabolic condition in which the need for functional bioengineered substitutes (e.g., scaffolds for tissue engineering) is likely to occur. However, the adverse foreign body response (FBR) that invariably takes place adjacent to implant devices impairing their function is poorly characterized in this condition. This study investigated the influence of obesity on the host response to a synthetic matrix implanted subcutaneously in high-fat-fed obese mice.

METHODS

Histological analysis of 14-day-old implants was performed to identify collagen deposition, capsule thickness, fibroblast-like cells, foreign body giant cells, and mast cells. In addition, transforming growth factor β1 (TGF-β1) levels in the implants and serum were determined.

RESULTS

All fibrogenic markers (and TGF-β1 levels) increased in the implants of obese mice compared with their nonobese counterparts. Particularly relevant was the fibrous capsule thickness in implants of obese mice (234.2 ± 22.1 µm vs. 109.2 ± 13.4 µm in implants of nonobese animals).

CONCLUSIONS

The study results showing that obesity upregulates the main features of the FBR induced by subcutaneous implants in mice may be relevant in understanding biomaterial integration and performance in this condition. This is crucial to the development of strategies to maintain the integrity and function of implantable devices.

Relationship between sleep characteristics and measures of body size and composition in a nationally-representative sample

BACKGROUND

Short sleep has been linked to obesity. However, sleep is a multidimensional behavior that cannot be characterized solely by sleep duration. There is limited study that comprehensively examined different sleep characteristics in relation to obesity.

METHODS

We examined various aspects of sleep in relation to adiposity in 2005-2006 NHANES participants who were 18 or older and free of cardiovascular disease, cancer, emphysema, chronic bronchitis and depression (N = 3995). Sleep characteristics were self-reported, and included duration, overall quality, onset latency, fragmentation, daytime sleepiness, snoring, and sleep disorders. Body measurements included weight, height, waist circumference, and dual-energy X-ray absorptiometry measured fat mass.

RESULTS

Snoring was associated with higher BMI (adjusted difference in kg/m² comparing snoring for 5+ nights/week with no snoring (95 % confidence interval), 1.85 (0.88, 2.83)), larger waist circumference (cm, 4.52 (2.29, 6.75)), higher percentage of body fat (%, 1.61 (0.84, 2.38)), and higher android/gynoid ratio (0.03 (0.01, 0.06)). The associations were independent of sleep duration and sleep quality, and cannot be explained by the existence of sleep disorders such as sleep apnea. Poor sleep quality (two or more problematic sleep conditions) and short sleep duration (<6 h) were also associated with higher measures of body size and fat composition, although the effects were attenuated after snoring was adjusted.

CONCLUSION

In a nationally representative sample of healthy US adults, snoring, short sleep, and poor sleep quality were associated with higher adiposity.

Body Mass Index Moderates the Association between Sleep Quality and Vigilance on a Test of Inhibitory Control

OBJECTIVE

Sleep problems are common among college students and related to numerous adverse outcomes including impaired cognitive performance. Obesity may confer an elevated risk of cognitive deficits with poor sleep given its relationship with poorer sleep quality and impaired cognition. Thisstudy examined whether the relationship between reduced sleep quality and poorer vigilance and inhibitory control were moderated by elevated body mass index (BMI).

METHOD

Participants were 85 college students who completed a computerized task of inhibitory control that required vigilance (go/no-go [GNG] task) and the Pittsburgh Sleep Quality Index, a measure of sleep quality.

RESULTS

Poor sleep quality was observed in 63.5% of the sample and was related to more omission errors on the GNG task and increased BMI. Results further revealed that BMI moderated the relationship between sleep quality and performance on the GNG task such that individuals in the severely obese range of BMI had more omission errors with poorer sleep quality, while there was no association between sleep and GNG performance among normal weight and overweight individuals.

CONCLUSIONS

These findings highlight the likely contribution of obesity to decreased vigilance with poor sleep. Future research is needed to confirm these findings using objective measures of sleep quality (e.g., actigraphy, polysomnography).

Social and Behavioral Determinants of Perceived Insufficient Sleep

Insufficient sleep is associated with cardiometabolic disease and poor health. However, few studies have assessed its determinants in a nationally representative sample. Data from the 2009 behavioral risk factor surveillance system were used (N = 323,047 adults). Insufficient sleep was assessed as insufficient rest/sleep over 30 days. This was evaluated relative to sociodemographics (age, sex, race/ethnicity, marital status, region), socioeconomics (education, income, employment, insurance), health behaviors (diet, exercise, smoking, alcohol), and health/functioning (emotional support, BMI, mental/physical health). Overall, insufficient sleep was associated with being female, White or Black/African-American, unemployed, without health insurance, and not married; decreased age, income, education, physical activity; worse diet and overall health; and increased household size, alcohol, and smoking. These factors should be considered as risk factors for insufficient sleep.

Sleep duration differences between children of migrant and native origins

Aim

To explore whether primary school children of migrant and native Dutch origins differ regarding their sleep duration per night, a risk for overweight and obesity, and to determine to what degree differences in parenting styles contribute to these differences.

Subjects and methods

A cross-sectional survey, including 1,943 children aged 8-9 years old and their primary caregivers, was performed. Data were collected from primary schools in cities and adjacent municipalities in The Netherlands: Eindhoven and Rotterdam. The outcome measure was mean sleep duration per night. The main independent variable was migrant background, based on the country of birth of the parents. A possible mediating variable was parenting style (rejecting, neglecting, permissive, authoritarian, authoritative). Age and sex of the child as well as parental socioeconomic status, as indicated by educational level, were added as confounders.

Results

Dutch children have the highest sleep duration: more than 11 h (mean = 670.1; SD = 27.7). All migrant children show less than 11 h of sleep per night. Migrant children of non-Western origin, especially Turkish and Moroccan children, show the lowest sleep duration per night. Parenting styles do not contribute to these differences.

Conclusion

Migrant background is associated with sleep duration. As children of migrant origin are, in general, at higher risk for overweight and obesity and sleep duration is regarded as a risk factor for overweight and obesity, further investigation of this association is needed.

The Association between Sleep Duration and Non-Alcoholic Fatty Liver Disease among Japanese Men and Women

OBJECTIVE

To examine the relationship between sleep duration and non-alcoholic fatty liver disease (NAFLD).

METHODS

We evaluated 3,968 subjects who underwent health check-ups from June 2012 to May 2013 at the Watari Hospital Health Center in Fukushima Prefecture in Japan. Fatty liver was detected by ultrasonography. Sleep duration and lifestyle factors were estimated using a questionnaire. Sleep duration was categorized into the following groups: ≤ 6, 6 to ≤ 7, >7 to ≤ 8, and >8 h. The four sleep duration groups were compared using the χ(2) test and Kruskal-Wallis test.

RESULTS

In total, 2,172 subjects were enrolled. The overall prevalence of NAFLD was 29.6% (men, 38.0%; women, 25.3%). The proportion of NAFLD tended to decrease as sleep duration increased in men. The proportion with NAFLD was lowest in the group with a sleep duration of 6 to ≤ 7 h and highest in the groups with sleep durations of ≤ 6 and >8 h in women. The distribution showed a U-shaped curve. The age-adjusted odds ratio (OR) (95% confidence interval (CI)) for subjects with NAFLD with a sleep duration ≤ 6 h compared to the reference (6 to ≤ 7 h) was 1.44 (1.06-1.96) in women.

CONCLUSION

Sleep shortage tends to be associated with NAFLD in women and may be mediated by body adiposity.

Sleep duration and total and cause-specific mortality in a large US cohort: interrelationships with physical activity, sedentary behavior, and body mass index

Both short and long durations of sleep are associated with higher mortality, but little is known about the interrelationship between sleep and other modifiable factors in relation to mortality. In the National Institutes of Health-AARP Diet and Health Study (1995-1996), we examined associations between sleep duration and total, cardiovascular disease (CVD), and cancer mortality among 239,896 US men and women aged 51-72 years who were free of cancer, CVD, and respiratory disease. We evaluated the influence of moderate-to-vigorous physical activity, television viewing, and body mass index (BMI; weight (kg)/height (m)(2)) on the sleep-mortality association and assessed their combined association with mortality. During an average of 14 years of follow-up, we identified 44,100 deaths. Compared with 7-8 hours of sleep per day, both shorter and longer sleep durations were associated with higher total and CVD mortality. We found a greater elevation in CVD mortality associated with shorter sleep among overweight and obese people, suggesting a synergistic interaction between sleep and BMI. People in the unhealthy categories of all 4 risk factors (sleep <7 hours/day, moderate-to-vigorous physical activity ≤1 hour/week, television viewing ≥3 hours/day, and BMI ≥25) had significantly higher all-cause (relative risk (RR) = 1.42, 95% confidence interval (CI): 1.34, 1.52), CVD (RR = 1.90, 95% CI: 1.67, 2.17), and cancer (RR = 1.21, 95% CI: 1.09, 1.34) mortality. Short sleep duration may predict higher mortality, particularly CVD mortality, among overweight and obese people.

Sleep duration and obesity among adolescents transitioning to adulthood: do results differ by sex?

OBJECTIVES

To examine the association between short sleep duration and obesity among adolescents (mean age 16 years) transitioning into young adulthood (mean age 21 years) in the National Longitudinal Study of Adolescent Health (N = 10,076).

STUDY DESIGN

Self-reported sleep duration was categorized as <6, 6-8, or >8 hours. Obesity status, using measured height and weight, was defined as body mass index ≥95th percentile in adolescence and body mass index ≥30 kg/m(2) in young adulthood.

RESULTS

Cross-sectionally, short sleep duration was associated with obesity in adolescent males (prevalence ratio 1.8 [95% CI, 1.3-2.4]) but not in females (prevalence ratio 1.0 [95% CI, 0.7-1.4]). In longitudinal analyses, short sleep duration in adolescence was associated with incident obesity in both males and females (risk ratio 1.2 [95% CI, 1.0-1.6]) in young adulthood. No interactions by sex were noted.

CONCLUSIONS

Analyzing the association of sleep duration and obesity longitudinally resolved sex discrepancies observed in earlier cross-sectional analyses. Optimizing sleep duration during adolescence may be an effective intervention to prevent excess weight gain in young adults.

Sleep duration, sleep quality, and obesity risk among older adults from six middle-income countries: findings from the study on global AGEing and adult health (SAGE)

OBJECTIVES

Changes in sleep patterns often occur in older adults. Previous studies have documented associations between sleep duration, sleep quality, and obesity risk in older individuals, yet few studies have examined these trends in lower-income countries. The present cross-sectional study uses nationally representative datasets from six countries to examine these relationships.

METHODS

Two hypotheses related to obesity risk and sleep patterns were tested using data from the first wave of the World Health Organization's Study on global AGEing and adult health (SAGE). This longitudinal study draws on samples of older adults (>50 years old) in six middle-income countries (China, Ghana, India, Mexico, Russian Federation, and South Africa). Self-report data were used to measure sleep duration, sleep quality, lifestyle and sociodemographic information, while anthropometric measurements were collected to assess body mass index (BMI) and waist circumference (WC). Multiple linear regressions were used to examine the relationship between sleep patterns and obesity risk while controlling for lifestyle factors.

RESULTS

Shorter sleep durations in both men and women were significantly associated with higher BMI and WC measures (P < 0.05). Low sleep quality did not significantly contribute to increased obesity risk. Surprisingly, high sleep quality was significantly associated with increased male BMI and WC in China and India (P < 0.01).

CONCLUSIONS

This study documented an association between short sleep duration and increased obesity risk, which is important given the global increase of obesity-related diseases.

Night time sleep macrostructure is altered in otherwise healthy 10-year-old overweight children

OBJECTIVE

Epidemiological evidence shows an inverse relationship between sleep duration and overweight/obesity risk. However, there are few polysomnographic studies that relate the organization of sleep stages to pediatric overweight (OW). We compared sleep organization in otherwise healthy OW and normal-weight (NW) 10-year-old children.

SUBJECTS

Polysomnographic assessments were performed in 37 NW and 59 OW children drawn from a longitudinal study beginning in infancy. Weight and height were used to evaluate body mass index (BMI) according to international criteria. Non-rapid eye movement (NREM) sleep (stages N1, N2 and N3), rapid eye movement (REM) sleep (stage R) and wakefulness (stage W) were visually scored. Sleep parameters were compared in NW and OW groups for the whole sleep period time (SPT) and for each successive third of it using independent Student's t-tests or nonparametric tests. The relationship between BMI and sleep variables was evaluated by correlation analyses controlling for relevant covariates.

RESULTS

The groups were similar in timing of sleep onset and offset, and sleep period time. BMI was inversely related to total sleep time (TST) and sleep efficiency. OW children showed reduced TST, sleep efficiency and stage R amount, but higher stage W amount. In analysis by thirds of the SPT, the duration of stage N3 episodes was shorter in the first third and longer in the second third in OW children as compared with NW children.

CONCLUSIONS

Our results show reduced sleep amount and quality in otherwise healthy OW children. The lower stage R amount and changes involving stage N3 throughout the night suggest that OW in childhood is associated with modifications not only in sleep duration, but also in the ongoing night time patterns of NREM sleep and REM sleep stages.

Does Short Sleep Lead to Obesity Among Children and Adolescents? Current Understanding and Implications

Childhood obesity continues to be a major public health concern in the United States. This work reviews the current understanding of the relationship between sleep duration and obesity among children and adolescents. A systematic search was conducted for papers published between January 2000 and July 2013 using keywords: (sleep) and (overweight or obesity or obese or body mass index or BMI or adiposity or body fat or fat) and (children or child or youth or teen or pediatric or adolescent or paediatric or childhood or adolescence or boy or girl). Reference lists of relevant articles and reviews or meta-analysis articles were checked to identify additional studies. Only empirical work and longitudinal studies that focused on children and adolescents were included in this review. The search identified 22 longitudinal studies. The majority of the reviewed studies support the presence of an inverse relationship between sleep duration and obesity. However, in some studies the relationship was not significant in adjusted analyses. Differences as a function of age and gender were also noted. Despite more than a decade of research, the debate on the association between sleep duration and obesity continues. Further research with repeated assessments, valid objective measures, and better control of potential confounding variables is warranted.

Lack of sleep could increase obesity in children and too much television could be partly to blame

AIM

To examine the bidirectional relationship between short sleep duration and body mass index (BMI). A secondary aim was to investigate whether reduced physical activity and increased screen time (television and computer use) mediated these associations.

METHODS

This study utilised data from the Longitudinal Study of Australian Children, which is an observational cohort study of Australian children. The sample included 2984 (52.4% boys) children followed from 4 to 5 years of age until 8 to 9 years of age. Sleep duration, screen time and covariates were reported by parents, with BMI measured objectively. Cross-lagged modelling investigated the bidirectional association between sleep duration and BMI; lagged panel mediation modelling examined physical activity and screen time as potential mediators.

RESULTS

Short sleep duration at 4 to 5 years of age was significantly associated with higher BMI at 8 to 9 years of age (β= -.07, p = .044). The relationship between short sleep duration at 4 to 5 years of age and higher BMI at 8 to 9 years of age was partially mediated by increased television viewing at 6 to 7 years of age (β = -.01, 95% confidence interval [-.02, -.002]).

CONCLUSION

Short sleep duration could be a risk factor for obesity in children. Increased television viewing may be one mechanism underlying this longitudinal relationship.

A large prospective investigation of sleep duration, weight change, and obesity in the NIH-AARP Diet and Health Study cohort

The relationship between sleep and obesity or weight gain in adults, particularly older populations, remains unclear. In a cohort of 83,377 US men and women aged 51-72 years, we prospectively investigated the association between self-reported sleep duration and weight change over an average of 7.5 years of follow-up (1995-2004). Participants were free of cancer, heart disease, and stroke at baseline and throughout the follow-up. We observed an inverse association between sleep duration per night and weight gain in both men (P for trend = 0.02) and women (P for trend < 0.001). Compared with 7-8 hours of sleep, shorter sleep (<5 hours or 5-6 hours) was associated with more weight gain (in kilograms; men: for <5 hours, β = 0.66, 95% confidence interval (CI): 0.19, 1.13, and for 5-6 hours, β = 0.12, 95% CI: -0.02, 0.26; women: for <5 hours, β = 0.43, 95% CI: 0.00, 0.86, and for 5-6 hours, β = 0.23, 95% CI: 0.08, 0.37). Among men and women who were not obese at baseline, participants who reported less than 5 hours of sleep per night had an approximately 40% higher risk of developing obesity than did those who reported 7-8 hours of sleep (for men, odds ratio = 1.45, 95% CI: 1.06, 1.99; for women, odds ratio = 1.37, 95% CI: 1.04, 1.79). The association between short sleep and excess weight gain was generally consistent across different categories of age, educational level, smoking status, baseline body mass index, and physical activity level.

Association between body mass index and sleep duration assessed by objective methods in a representative sample of the adult population

INTRODUCTION

Sleep duration has been associated with overweight individuals in many epidemiological studies; however, few studies have assessed sleep using objective methods. Our study was designed to evaluate the association between body mass index (BMI) and sleep duration measured by actigraphy (Acti), polysomnography (PSG) and the Pittsburgh sleep quality index questionnaire (PSQIO). Furthermore, we evaluated other biochemical and polysomnographic parameters.

METHODS

A representative sample of 1042 individuals from Sao Paulo, Brazil, including both genders (20-80 yrs), participated in our protocol. Weight and other anthropometric parameters were measured at the onset of the study. Sleep duration was calculated by Acti, PSG, and the PSQIQ. The population was sorted by sleep duration, body, slow wave sleep (SWS) and REM sleep (REMS) duration subsets. In addition, other biochemical and polysomnographic parameters were analyzed. Differences between population subsets were analyzed by one-way analysis of variance (ANOVA). Linear regression analysis was performed between sleep and anthropometric parameters.

RESULTS

Shorter sleep duration was associated with higher BMI and waist and neck circumference when measured by Acti and PSG (p<0.05). Lower leptin levels were associated with short sleep in normal-weight (BMI>18 and ⩽25) individuals (p<0.01). The association between short sleep duration Acti and higher BMI was present when apnea-hypopnea index (AHI) was less than 15 (p=0.049). Shorter REMS and SWS also were associated with higher BMI (p<0.01). Normal-weight individuals tended to sleep longer, have higher sleep efficiency and longer SWS and REMS than obese individuals (Acti, PSG; p=0.05). Sleep duration was negatively correlated with BMI (Acti, PSG; p<0.05). Short SWS and REMS were associated with higher cardiovascular risk factors (p<0.05).

CONCLUSION

Shorter sleep, SWS, and REMS duration were associated with higher BMI, central adiposity measurements, and cardiovascular risk factors when measured by objective methods.

Sleep duration versus sleep insufficiency as predictors of cardiometabolic health outcomes

OBJECTIVE

The objective of the present study was to investigate the relationship between sleep insufficiency and sleep duration, particularly regarding negative cardiometabolic health outcomes already considered to be affected by reduced sleep time.

METHODS

A total of N=30,934 participants from the 2009 Behavioural Risk Factor Surveillance System (BRFSS) answered questions about their sleep duration as well as subjective feelings of sleep insufficiency. Outcomes included body mass index (BMI), obesity (BMI ≥ 30kgm(-2)) and history of hypertension, diabetes, hypercholesterolaemia, heart attack and stroke. Linear and logistic regression models examined whether cardiometabolic outcomes were associated with (1) sleep duration alone, (2) sleep insufficiency alone and (3) the combined effect of sleep duration and sleep insufficiency.

RESULTS

Results indicated that, when examined alone, sleep duration <5h (versus 7h) was related to BMI (B=2.716, p<0.01), obesity (B=2.080, p<0.000001), diabetes (B=3.162, p<0.000001), hypertension (B=2.703, p<0.000001), hypercholesterolaemia (B=1.922, p<0.00001), heart attack (B=4.704, p<0.000001) and stroke (B=4.558, p<0.000001), and sleep insufficiency (days per week, continuous) was related to BMI (B=0.181, p<0.01), obesity (B=1.061, p<0.000001) and hypercholesterolaemia (B=1.025, p<0.01). All of these relationships remained significant after adjustment for covariates, except for diabetes and sleep duration. Also, after adjustment, a significant relationship between insufficient sleep and hypertension emerged (B=1.039, p<0.001). When evaluated together, after adjustment for covariates, significant relationships remained between sleep duration <5h (versus 7h) and BMI (B=1.266, p<0.05), obesity (B=1.389, p<0.05), hypertension (B=1.555, p<0.01), heart attack (B=2.513, p<0.01) and stroke (B=1.807, p<0.05). It should be noted that relationships between sleep duration >9h (versus 7h) were seen for heart attack (B=1.863, p<0.001) and stroke (B=1.816, p<0.01). In these models, sleep insufficiency was associated with hypercholesterolaemia (B=1.031, p<0.01) and hypertension (B=1.027, p<0.05).

CONCLUSIONS

These analyses show that both sleep duration and insufficiency are related to cardiometabolic health outcomes, and that when evaluated together, both variables demonstrate unique effects.

Sleep and obesity: a focus on animal models

The rapid rise in obesity prevalence in the modern world parallels a significant reduction in restorative sleep (Agras et al., 2004; Dixon et al., 2007, 2001; Gangwisch and Heymsfield, 2004; Gupta et al., 2002; Sekine et al., 2002; Vioque et al., 2000; Wolk et al., 2003). Reduced sleep time and quality increases the risk for obesity, but the underlying mechanisms remain unclear (Gangwisch et al., 2005; Hicks et al., 1986; Imaki et al., 2002; Jennings et al., 2007; Moreno et al., 2006). A majority of the theories linking human sleep disturbances and obesity rely on self-reported sleep. However, studies with objective measurements of sleep/wake parameters suggest a U-shaped relationship between sleep and obesity. Studies in animal models are needed to improve our understanding of the association between sleep disturbances and obesity. Genetic and experimenter-induced models mimicking characteristics of human obesity are now available and these animal models will be useful in understanding whether sleep disturbances determine propensity for obesity, or result from obesity. These models exhibit weight gain profiles consistently different from control animals. Thus a careful evaluation of animal models will provide insight into the relationship between sleep disturbances and obesity in humans. In this review we first briefly consider the fundamentals of sleep and key sleep disturbances, such as sleep fragmentation and excessive daytime sleepiness (EDS), observed in obese individuals. Then we consider sleep deprivation studies and the role of circadian alterations in obesity. We describe sleep/wake changes in various rodent models of obesity and obesity resistance. Finally, we discuss possible mechanisms linking sleep disturbances with obesity.

Potential contributors to the canadian pediatric obesity epidemic

As a group, Canadian children and youth are heavier than at any time in the recent past. However, to date there has been no critical examination of the factors which are likely to have contributed to these deleterious trends. A review of the evidence suggests that there is robust evidence supporting the role of reduced sleep, increased sedentary time, increased consumption of sugar-sweetened beverages, and secular increases in adult obesity as contributing factors to the current epidemic of childhood obesity. There is moderate evidence that these trends are related to changes in either total energy intake or physical activity, while there is very little evidence supporting the role of maternal age, breastfeeding, exposure to endocrine disrupters, or inadequate calcium intake. These findings suggest that targeting sleep, sedentary time, and sugar-sweetened beverage intake in Canadian children and youth may help to prevent future weight gain at the population level.

Sleep, brain energy levels, and food intake: Relationship between hypothalamic ATP concentrations, food intake, and body weight during sleep-wake and sleep deprivation in rats

BACKGROUND

The feeling of hunger and feeding, a wake-state-dependent behavior, is regulated by specific centers within the hypothalamus. While paraventricular nucleus (PVN), arcuate nucleus (ARC), and dorso- and ventromedial hypothalamus (DMH/VMH) regulate feeding, the lateral hypothalamus (LH) is associated both with feeding and wake/REM sleep regulation. In order to examine the effects of sleep and wakefulness on food intake and body weight, we also measured hypothalamic ATP concentrations, which are known to be involved in feeding behavior and sleep-wake regulation.

METHODS

In rats, food intake and body weight was measured during a 24-h light-dark cycle and during 6 h of sleep deprivation (SD) performed by gentle handling. Tissue samples from the PVN, ARC/DMH/VMH, and LH were collected after 6 h of SD and from time-matched diurnal controls. ATP was measured by luciferin-luciferase bioluminescence assay.

RESULTS

Across the 24-h light-dark period, rats consumed approximately 28.13±4.48 g of food and gained 5.22±1.65 g with a positive correlation between food intake and body weight. During SD, while food intake increased significantly +147.31±6.13%, they lost weight significantly (-93.29±13.64%) when compared to undisturbed controls. SD resulted in a significant decrease in ATP levels only in LH (-44.60±21.13%) with no change in PVN, ARC/DMH/VMH region when compared with undisturbed controls.

CONCLUSION

The results indicate a strong overall correlation between ATP concentrations in the LH and individual food intake and suggest a sleep-wake dependent neuronal control of food intake and body weight.

Short sleep mediates the association between long work hours and increased body mass index

This study examined whether short sleep duration, physical activity and time spent sitting each day mediated the association between long work hours and body mass index (BMI). Participants included 16,951 middle aged Australian adults who were employed in full time work (i.e. ≥35 h a week). Data on BMI, sleep duration, work hours and other health and demographic variables were obtained through a self-report questionnaire. A multiple mediation model was tested whereby sleep duration, physical activity and amount of time spent sitting were entered as potential mediators between work hours and BMI. The results demonstrated that short sleep partially mediated the association between long work hours and increased BMI in males. In females, long work hours were indirectly related to higher BMI through short sleep. The results provide some support for the hypothesis that long work hours could contribute to obesity via a reduction in sleep duration; this warrants further investigation in prospective studies.

Is sleep duration associated with obesity in older Australian adults?

OBJECTIVES

To investigate the relationship between sleep duration and obesity in older Australian adults.

METHOD

Self-reported health data were collected through the 45 and Up Study. Multinomial logistic regression models were used to test the relationship between sleep duration and body mass index, controlling for a range of demographic and health-related variables.

RESULTS

The sample included 45,325 Australian adults aged 55 to 95 years. The regression models demonstrated that short and long sleep were associated with obesity in 55- to 64-year-olds but not in those aged 65 years and above.

DISCUSSION

The present results suggest that the relationships between sleep duration and obesity previously reported in young and middle-aged adults are not evident in older adults. The absence of these relationships could reflect a combination of age-related factors that impact on sleep and body composition.