Beyond sleep duration: Sleep timing as a risk factor for childhood obesity

Maternal-child overweight relationship, assessment of maternal perception of child weight status and feeding behaviours

BACKGROUND

Parents play a key role in constructing children' behaviours. We studies maternal-child overweight relationship and compared maternal perception of child weight status and feeding behaviours between groups of normal-weight and overweight children.

METHODS

The cross-sectional study was conducted on 192 girls aged 10-13 years and their mothers. They were divided to two groups of overweight (n = 94) and normal-weight (n = 98) children. Anthropometric characteristics were measured for children and mothers. Logistic regression analysis was used to examine the association between child overweight and tertiles of maternal body mass index (BMI). Maternal perception of child's weight status and her engagement in promoting child's healthy behaviours was assessed.

RESULTS

BMI and waist circumference was significantly higher in children (P < 0.001) and mothers (P < 0.01) of overweight compared to normal-weight group. There was a significant relationship between children's overweight and tertiles of maternal BMI, which remained significant after adjusting for potential confounders. Mothers of overweight children were more concerned for their child's overeating and overweight, and for compelling the child to diet to maintain a desirable weight (P < 0.001). In contrast, mothers of normal-weight children restricted sugar-sweetened drinks (P = 0.008), offered fruit and vegetables (P = 0.035), and helped their children to get enough physical activity (P = 0.022) and night sleep (P = 0.001) more than mothers in other group.

CONCLUSIONS

This study showed a strong relationship between children and mothers' overweight. Despite being more concerned about their child weight status, mothers of overweight children reported behaviours which were less encouraging the children for healthy eating and lifestyle than mothers of normal-weight children.

Relationship between social jetlag and body mass index in nurses working shift schedules: a cross-sectional study

This study aimed to explore the relationship between shift-working nurses' social jetlag and body mass index (BMI) and provide a theoretical basis for nursing managers to develop appropriate health interventions. Shift work is unavoidable in nursing and is associated with circadian rhythm disorders. Social jetlag is prevalent in shift-working nurses and is associated with adverse health outcomes (particularly metabolism-related indicators). BMI is a significant metabolic indicator, and research has demonstrated its effectiveness in predicting the formation of metabolic syndrome. The relationship between social jetlag and BMI can be explained by considering physiological, psychological, and behavioral factors. However, most studies on social jetlag and health status are focused on non-shift nurse populations, with fewer studies on shift workers. Five tertiary hospitals located at similar latitudes in Southwest China were selected for the study. We surveyed 429 shift-working nurses using sociodemographic data, the Munich Chronotype Questionnaire for Shift Workers, and BMI. The restricted cubic spline model was used to analyze the relationship between social jetlag and BMI among shift-working nurses, and segmented linear regression was performed around the inflection point using multiple linear regression analysis. The results revealed that social jetlag (82.0 [85.0] min) was experienced by 64.6% of the shift-working nurses. After controlling for confounding variables, the model with seven knots had the lowest accepted Akaike information criterion value, and there was a U-shaped relationship between shift-working nurses' BMI and social jetlag in this model; its inflection (lowest) point of 20.7 was considered the cut-off point. Segmented regression showed that for BMI < 20.7, BMI was significantly negative with standardized social jetlag; whereas with BMI > 20.7, BMI was significantly positive with standardized social jetlag. BMI has a U-shaped relationship with social jetlag, and attention should be paid to overweight or underweight shift-working nurses to detect early circadian rhythm disorder. Shift-working nurses with high social jetlag tended to have higher/lower BMI, which should be further investigated in the future, to minimize metabolic diseases among them.

Barriers to Care for Pediatric Patients with Obesity

This review article emphasizes the challenges pediatric patients face during obesity treatment. Prior research has been compartmentalized, acknowledging that stigma, the ability to implement lifestyle changes, social health determinants, and healthcare accessibility are considerable impediments for obese children. These issues emerge at various levels, including the individual or family, the community and school, and even national policy. This suggests the need for a more comprehensive, team-based approach to tackle pediatric obesity. Understanding these barriers is the first step toward creating effective strategies and solutions to overcome these challenges.

The Importance of Sleep in Overcoming Childhood Obesity and Reshaping Epigenetics

The development of childhood obesity is a complex process influenced by a combination of genetic predisposition and environmental factors, such as sleep, diet, physical activity, and socioeconomic status. Long-term solutions for decreasing the risk of childhood obesity remain elusive, despite significant advancements in promoting health and well-being in school and at home. Challenges persist in areas such as adherence to interventions, addressing underlying social determinants, and individual differences in response to treatment. Over the last decade, there has been significant progress in epigenetics, along with increased curiosity in gaining insights into how sleep and lifestyle decisions impact an individual's health. Epigenetic modifications affect the expression of genes without causing changes to the fundamental DNA sequence. In recent years, numerous research studies have explored the correlation between sleep and the epigenome, giving a better understanding of DNA methylation, histone modification, and non-coding RNAs. Although significant findings have been made about the influence of sleep on epigenetics, a notable gap exists in the literature concerning sleep-related genes specifically associated with childhood obesity. Consequently, it is crucial to delve deeper into this area to enhance our understanding. Therefore, this review primarily focuses on the connection between sleep patterns and epigenetic modifications in genes related to childhood obesity. Exploring the interplay between sleep, epigenetics, and childhood obesity can potentially contribute to improved overall health outcomes. This comprehensive review encompasses studies focusing on sleep-related genes linked to obesity.

Assessing Moroccan physician knowledge and practices regarding maternal obesity's impact on childhood obesity: Implications for prevention and intervention

BACKGROUND

Childhood obesity is a growing global concern with far-reaching health implications. This study focuses on evaluating the knowledge and practices of physicians in Morocco regarding the link between maternal obesity and childhood obesity. Despite the increasing prevalence of childhood obesity worldwide, this issue remains inadequately addressed in the Moroccan context.

AIM

To assess the awareness and practices of physicians in Morocco concerning the connection between maternal obesity and childhood obesity.

METHODS

The research encompasses a comprehensive survey of practicing physicians, revealing significant gaps in awareness and practices related to maternal obesity.

RESULTS

Notably, a significant portion of doctors do not provide adequate guidance to overweight pregnant women, highlighting the urgency for targeted educational programs.

CONCLUSION

In conclusion, this research illuminates critical areas for improvement in tackling childhood obesity in Morocco. By addressing these gaps, fostering awareness, and enhancing medical practices, the healthcare system can contribute significantly to preventing childhood obesity and improving the overall health of future generations.

Late bedtime combined with more screen time before bed increases the risk of obesity and lowers diet quality in Spanish children

This cross-sectional study aimed to investigate whether the combination of bedtime and screen time (ST) before bed were associated with obesity and diet quality in toddlers and school-aged children. Parents reported children's bedtimes and ST before bed (0 min, 1-30 min, >30 min). We then defined bed + screen time behavior using bedtime median cut-offs (early [EB] or late [LB]) and ST responses, resulting in four groups: EB-0'ST, EB ≤ 30'ST/LB-0'ST, EB > 30'ST/LB ≤ 30'ST, and LB > 30'ST. For all participants (n = 1133; 5.4 ± 2.7 years, 49.7% girls, 51.9% school-aged) we evaluated body mass index (BMI), diet quality, sleep-related variables, physical activity, and health-related quality of life (HRQoL). Outcome variables were compared across bed + screen time behavior groups, stratified by age group (toddlers and school-aged children) using general linear models for continuous variables, as well as chi-squared tests or logistic regressions for categorical variables. Additionally, we calculated linear p-trends. Analyses were adjusted for sociodemographic variables, BMI, and physical activity (unless the variable was tested). The results showed that toddlers and school-aged children in the LB ≥ 30'ST group were more likely to have overweight/obesity (OR: 3.42 [95%CI:1.41,8.26] and OR: 2.53 [95%CI:1.10,5.03], respectively) than those in the EB-0'ST group. Additionally, toddlers and school-aged children in the EB > 30'ST/LB ≤ 30'ST and LB > 30'ST groups showed significantly lower adherence to the Mediterranean diet compared to the other groups (p < 0.001). Regarding sleep-related outcomes, we observed that the combination of LB and more ST was associated with poorer sleep quality and shorter sleep duration in toddlers and school-aged children (p < 0.001). These findings emphasize the importance of promoting earlier bedtimes and limiting ST before bed as part of obesity prevention strategies for children. Furthermore, such intervention could benefit the quality of children's diet and overall lifestyle.

Relationship between 24-h activity behavior and body fat percentage in preschool children: based on compositional data and isotemporal substitution analysis

OBJECTIVE

This study aims to elucidate the dose‒response relationship between 24-h activity behaviors and body fat percentage (BFP) in Chinese preschool children using a compositional isotemporal substitution model (ISM).

METHODS

In a cross-sectional design, 881 children aged 3-6 from urban and rural areas of Jiangxi Province were sampled. Activity behaviors, including sedentary behavior (SB), low-intensity physical activity (LPA), and moderate- to high-intensity physical activity (MVPA), were measured using accelerometers. Sleep patterns were assessed through questionnaires, and BFP was determined by bioelectrical impedance analysis (BIA). The study employed compositional data analysis (CoDA) and ISM to estimate the impact of reallocating durations of different activity behaviors on BFP.

RESULTS

Higher BFP was found in urban vs. rural children, decreasing with age. Overweight and obesity rates were 10.6% and 7.6%, respectively, above national averages. MVPA and LPA were negatively correlated with BFP, while SB was positively correlated. A 30-min MVPA reduction significantly increased zBFR, particularly in overweight children. Gender-specific nuances revealed that boys' MVPA negatively influenced zBFP (β = -0.155), P < 0.05), while girls' SB positively impacted zBFP (β = 0.636, P < 0.01). Isotemporal simulations emphasized amplified effects in overweight children, with boys' zBFR rising rapidly when MVPA was substituted and girls displaying a notable substitution effect between SB and LPA.

CONCLUSION

BFP is closely linked to 24-h activity behaviors, notably in overweight and obese preschoolers. ISM identified MVPA as a critical influencer, with a 30-min reduction substantially increasing BFP. Gender disparities were evident, implicating MVPA in boys and LPA and SB in girls.

Wearable Devices Beyond Activity Trackers in Youth With Obesity: Summary of Options

Background: Current treatment protocols to prevent and treat pediatric obesity focus on prescriptive lifestyle interventions. However, treatment outcomes are modest due to poor adherence and heterogeneity in responses. Wearable technologies offer a unique solution as they provide real-time biofeedback that could improve adherence to and sustainability of lifestyle interventions. To date, all reviews on wearable devices in pediatric obesity cohorts have only explored biofeedback from physical activity trackers. Hence, we conducted a scoping review to (1) catalog other biofeedback wearable devices available in this cohort, (2) document various metrics collected from these devices, and (3) assess safety and adherence to these devices. Methods: This scoping review was conducted adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist. Fifteen eligible studies examined the use of biofeedback wearable devices beyond activity trackers in pediatric cohorts, with an emphasis on feasibility of these devices. Results: Included studies varied in sample sizes (15-203) and in ages 6-21 years. Wearable devices are being used to capture various metrics of multicomponent weight loss interventions to provide more insights about glycemic variability, cardiometabolic function, sleep, nutrition, and body fat percentage. High safety and adherence rates were reported among these devices. Conclusions: Available evidence suggests that wearable devices have several applications aside from activity tracking, which could modify health behaviors through real-time biofeedback. Overall, these devices appear to be safe and feasible so as to be employed in various settings in the pediatric age group to prevent and treat obesity.

The association of obstructive sleep apnea and behavioral insomnia in children ages 10 and under

STUDY OBJECTIVES

Behavioral insomnia of childhood (BIC) and obstructive sleep apnea (OSA) are highly prevalent conditions affecting 10%-20% and 1%-5% of children, respectively. Studies in adults and adolescents have suggested that comorbid insomnia and OSA may have distinct clinical characteristics. The association between the two conditions in the pediatric population has not been thoroughly investigated. This study aimed to examine the association between BIC and OSA in young children.

METHODS

Children, 6 months to 10 years old, referred to a sleep specialist and polysomnography at the Hadassah Medical Center between 2018 and 2021 were included in this retrospective analysis. We excluded children with chromosomal and craniofacial abnormalities, posttonsillectomy, or neurological impairment. BIC diagnosis was extracted from the electronic health records in accordance with the International Classification of Sleep Disorders, third edition criteria. OSA was diagnosed by polysomnography (apnea-hypopnea index > 2 events/h).

RESULTS

Of 312 children (age 4.42 ± 2.42 years), 126 (40.4%) were non-OSA non-BIC, 125 (40.1%) OSA non-BIC, 34 (10.9%) BIC non-OSA, and 27 (8.7%) comorbid insomnia and OSA. OSA and non-OSA children had a similar prevalence of BIC. Children in the comorbid insomnia and OSA group were significantly younger (2.22 ± 1.21 years). Younger age at polysomnography, premature birth, and increased periodic leg movements on polysomnography were independently associated with OSA in a multivariable analysis. Lower body mass index, regardless of OSA, was associated with BIC.

CONCLUSIONS

Current findings do not support an association between behavioral insomnia of childhood and obstructive sleep apnea in children. Healthcare providers should consider each of these sleep disorders in children presenting with sleep difficulties since each has distinct diagnostic and therapeutic options.

CITATION

Yelov L, Reiter J, Meira E Cruz M, Gileles-Hillel A. The association of obstructive sleep apnea and behavioral insomnia in children ages 10 and under. J Clin Sleep Med. 2024;20(2):245-251.

The relationship between multiple sleep dimensions and obesity in adolescents: A systematic review

Sleep is an involuntary behaviour, biologically fundamental to survival and wellbeing. However, sleep is increasingly neglected, with significant health implications. Recent research has identified associations between sleep duration, quality, timing and risk of overweight/obesity in children and adults. The aim of this review was to systematically identify and examine research that investigates the relationships between multiple objective and subjective sleep outcomes and objective adiposity measures in adolescents. A systematic review of literature, published to December 2022, was conducted using ten bibliographic databases. Search terms included objective and subjective sleep/circadian rhythm outcomes, objective adiposity measurements, and adolescents aged 8-18 years. Eighty-nine studies were included in the final review. Sleep outcomes were synthesized into three sleep domains: pre-sleep, during sleep and post-sleep outcomes. In summary, pre-sleep outcomes (including poor sleep hygiene, later chronotype and increased variability and later sleep timings) and increased sleep disturbance are consistently significantly associated with increased obesity and adiposity in adolescents. The relationship between during-sleep outcomes (sleep quality and efficiency) with adiposity and obesity measures was mixed. These findings suggest that adapting an individual's schedule to best suit chronotype preference and improving sleep hygiene, including a consistent bedtime routine, could reduce adiposity and obesity in adolescents.

Associations of social jetlag with physical activity and sedentary behaviour in children and adolescents: A systematic review and meta-analysis

Sleep and daytime movement behaviours occur co-dependently with each other within a finite 24 h day. Sleep parameters other than sleep duration, such as social jetlag and chronotype, have been linked to health problems and unhealthy behaviours among children and adolescents. Given the increasing number of studies examining sleep timing/chronotype and weight-related behaviours, including physical activity and sedentary behaviour, in the past decade, this systematic review and meta-analysis collated and evaluated the evidence on the relationships of social jetlag and chronotype with physical activity and sedentary behaviour among children and adolescents aged 3-17 years. Seven databases were searched on 16 March 2022, and 52 studies were identified as eligible for inclusion, 47 of which were suitable for the meta-analysis. A positive association was found between social jetlag and screen media use (r = 0.14, 95% CI: 0.04-0.24; I2  = 96%; p = 0.008). The morning chronotype was associated with a higher level of physical activity and a lower level of sedentary behaviour than the evening chronotype. No relationship was found between social jetlag and physical activity. The magnitude of heterogeneity among the included studies was high. Further experimental studies are urgently required to understand how circadian preference or misalignment affects activity behaviours. Interventions to promote an active lifestyle in young populations should consider their circadian preference, especially among individuals with the evening chronotype.

Circadian misalignment impacts the association of visceral adiposity with metabolic syndrome in adolescents

STUDY OBJECTIVES

Although insufficient sleep is a risk factor for metabolic syndrome (MetS), the circadian timing of sleep (CTS) is also involved in cardiac and metabolic regulation. We examined whether delays and deviations in the sleep midpoint (SM), a measure of CTS, modify the association between visceral adipose tissue (VAT) and MetS in adolescents.

METHODS

We evaluated 277 adolescents (median 16 years) who had at least 5 nights of at-home actigraphy (ACT), in-lab polysomnography (PSG), dual-energy X-ray absorptiometry (DXA) scan, and MetS score data. Sleep midpoint (SM), sleep irregularity (SI), and social jetlag (SJL) were examined as effect modifiers of the association between VAT and MetS, including waist circumference, blood pressure, insulin resistance, triglycerides, and cholesterol. Linear regression models adjusted for demographics, ACT-sleep duration, ACT-sleep variability, and PSG-apnea-hypopnea index.

RESULTS

The association between VAT and MetS was significantly stronger (p-values for interactions < 0.001) among adolescents with a schooldays SM later than 4:00 (2.66 [0.30] points increase in MetS score), a SI higher than 1 hour (2.49 [0.30]) or a SJL greater than 1.5 hours (2.15 [0.36]), than in those with an earlier SM (<3:00; 1.76 [0.28]), lower SI (<30 minutes; 0.98 [0.70]), or optimal SJL (<30 minutes; 1.08 [0.45]).

CONCLUSIONS

A delayed sleep phase, an irregular sleep-wake cycle, and greater social jetlag on schooldays identified adolescents in whom VAT had a stronger association with MetS. Circadian misalignment is a risk factor that enhances the impact of visceral obesity on cardiometabolic morbidity and should be a target of preventative strategies in adolescents.

Food Intake and Sleep Disorders in Children and Adolescents with Obesity

Over the last few decades, numerous scientific studies have investigated the possible association between sleep duration and adiposity during childhood, since it has been reported that sleep deprivation causes a related increase in caloric intake. Even though the underlying pathogenetic mechanisms are still under study and not completely known, the effect of dietetic habits and nutrient intake on sleep quality and patterns has been reported. The aim of this study is to explore the intricate interplay between food intake/diet patterns and pediatric sleep disturbances in children and adolescents with obesity, emphasizing the importance of not underestimating this aspect in the prevention and treatment of this complex disease. Recent evidence supports a high correlation between specific diet patterns and foods with sleep disturbances in children at all ages. Diets rich in fiber, fruit, vegetables, and anti-inflammatory nutrients and low in saturated fats seem to promote better sleep quality. Sleep disturbances are, in turn, risk factors for the development of obesity. Therefore, food strategies should be applied to counteract this harmful process. Unraveling the complex links between dietary habits, sleep patterns, and obesity is essential for developing effective strategies to combat this critical public health issue.

Excessive weight gain among preschool children during the COVID-19 lockdown in China: a retrospective observational study

OBJECTIVES

We aimed to analyse weight change and risk factors associated with excessive weight gain in preschool children during the COVID-19-related lockdown in western China.

METHODS

A retrospective observational study of eight randomly selected kindergartens was conducted. Data was collected via online electronic questionnaires during the lockdown.

RESULTS

During the COVID-19 lockdown period, the incidence of overweight and obesity among preschool children involved in the study was 7.6 and 14.7 %, respectively. In addition, the incidence of obesity among children aged 3-4 years was 26.3 %, which was higher than that of other age groups. Children with excessive weight gain (weight gain ≥1.0 kg) spent more time on TV and video viewing during lockdown than children with normal gain. Among children with excessive weight gain, weight before lockdown and fathers' BMI were higher than those of children with normal weight gain. Heavier weight before lockdown (OR 1.044, p<0.05), higher father's BMI (OR 1.022, p<0.05), fresh fruit consumption during lockdown (frequently, ≥5 times/week) (OR 5.946, p<0.05), and long touch-screen device time during lockdown (OR 1.259, p<0.05) were found to be risk factors significantly associated with excessive weight gain. Living space (80-100 m2, OR=0.499, p<0.05; 100-150 m2, OR=0.467, 95 % CI 0.26, 0.83) and good mental behavior during the lockdown (OR=0.056, p<0.05) were found to be significant protective factors against excessive weight gain.

CONCLUSIONS

There was a clear trend in excessive weight gain among preschool children during the COVID-19 lockdown, especially those who had already had heavier weight before the pandemic. The obesity-promoting environment resulting from the COVID-19 pandemic may lead to a further serious exacerbation of the childhood obesity pandemic. Therefore, child health care providers must pay close attention to this and implement effective preventive measures in a timely manner.

Association between Sleep Timing, Being Overweight and Meal and Snack Consumption in Children and Adolescents in Southern Brazil

Sleep timing is one of the dimensions of sleep that refers to the time of day when sleep occurs. It has been included in sleep-related research because of the potential associations between being overweight and the consumption of meals and snacks. This cross-sectional study aimed to investigate associations between sleep timing, meal and snack consumption and weight status in 1333 schoolchildren aged 7-14 years. The midpoint of sleep was used as a sleep timing measure obtained by the midpoint between bedtime and wake-up time, classified as Early, Intermediate, and Late. Schoolchildren in the Early group were less likely to be overweight (OR: 0.83, 95% CI 0.69; 0.99), and had higher odds of mid-morning snack consumption (OR: 1.95, 95% CI 1.56; 2.44) and lower probability to consume an evening snack (OR: 0.75, 95% CI 0.59; 0.94) compared with the Intermediate group. The Late group had lower odds of mid-morning snack consumption (OR: 0.67, 95% CI 0.55, 0.80) than the Intermediate group. The consumption of mid-morning and evening snacks was associated with the Early and Late midpoints of sleep. These results suggest that bedtime and wake-up time are relevant to consuming meals and snacks and may also be related to a greater probability of being overweight in children and adolescents.

Changes in objectively measured sleep after a multidisciplinary lifestyle intervention in children with abdominal obesity: A randomized trial

BACKGROUND/OBJECTIVE

childhood obesity and sleep disorders have a well-established cross-sectional association, but lifestyle interventions' effects on sleep quality remain under-researched. This study aimed to evaluate the sleep quality of 122 participants (7-16 years) with abdominal obesity after a 2-year necessary lifestyle intervention.

PATIENTS/METHODS

participants were assigned to either the intervention group (moderate hypocaloric Mediterranean Diet) or the usual care group (standard recommendations on a healthy diet). Sleep was objectively assessed using triaxial accelerometry, and sleep parameters analyzed included latency, efficiency, wake after sleep onset, total time in bed, total sleep time, number of awakenings, and awakening duration.

RESULTS AND CONCLUSIONS

the results showed that the intervention group significantly improved sleep latency at 12 and 24 months and improved sleep efficiency at 2 and 12 months, compared to the usual care group. Wake after sleep onset and the number of awakenings were significantly reduced at 24 months in the intervention group. Wake after sleep onset and leptin levels were positively associated in all participants. Total time in bed was inversely associated with triglycerides and metabolic score, and total sleep time was inversely associated with leptin, triglycerides, and metabolic score after the 2-month intervention. Triglyceride levels were inversely associated with total time in bed and total sleep time at one year, while the metabolic score was directly associated with wake after sleep onset and the number of awakenings and inversely associated with efficiency. In conclusion, the multidisciplinary intervention in children and adolescents with abdominal obesity reduced anthropometric parameters and improved sleep habits.

Effect of catch-up sleep on obesity in Korean adolescents: a nationwide cross-sectional study

Background

Adolescents have weekday/weekend sleep discrepancies and may compensate for weekday sleep debt through sleep extension on weekends.

Objective

We investigated the effects of total sleep duration on weekdays/weekends on obesity and determined if weekend catch-up sleep has an ameliorating effect on obesity in Korean adolescents.

Methods

Using data from the KNHANES VII, 1,306 middle and high school students were assessed for total sleep duration on weekdays, weekends, and the entire week, as well as weekend sleep extension. Participants were classified into four groups according to weekend sleep extension.

Results

Total sleep duration and weekend sleep duration were negatively associated with body mass index z-score. Increased weekend sleep duration and sleep extension on weekends decreased the relative risk of overweight/obesity with each 30 min increment, reducing the risk by a factor of 0.39 and 0.93, respectively. The risk of overweight/obesity in adolescents who slept less than 6 h on weekdays increased by a factor of 1.93 when they slept for less than 3 h on weekends.

Conclusion

Weekend catch-up sleep had a negative dose-dependent association with obesity in Korean adolescents. Sleeping longer on weekends may be associated with a decreased risk of obesity, even if the adolescent obtains less sleep during weekdays. However, further prospective studies are needed to establish the causality between extended weekend sleep and obesity.

Social jetlag is associated with adverse cardiometabolic latent traits in early adolescence: an observational study

Introduction

Adolescence is marked by physiological and social changes, such as puberty, increased responsibilities and earlier school start times. This often leads to insufficient sleep on school nights and the need to compensate for lost sleep on weekends, causing a misalignment between biological and social times, which has been termed social jetlag (SJL). SJL triggers stress responses and is associated with several negative health outcomes, including higher cardiometabolic risk in adults. In adolescence, however, SJL has only been consistently related to increases in adiposity but its association with other cardiometabolic indicators are unclear.

Method

In a sample of 278 healthy early adolescents (9-15 years of age; 168 girls) we investigated: 1) whether self-reported SJL is associated (using path analyses) with a cardiometabolic status latent factor obtained by testing the best fitting model via confirmatory factor analyses from an initial set of eight indicators [body mass index (BMI), waist/height ratio, triglyceride concentration, diastolic and systolic blood pressure, glycated hemoglobin, total cholesterol/high-density lipoprotein ratio (chol/HDL), and % body fat]; and 2) whether age and/or pubertal status influence the association between SJL and cardiometabolic status.

Result

We found that, for girls, higher SJL was associated with more adverse cardiometabolic latent scores (the shared variance of BMI, waist/height ratio, chol/HDL and systolic blood pressure, which had acceptable model fit indices). However, the role of age and pubertal status in this association was unclear for both sexes.

Discussion

SJL was associated with adverse cardiometabolic latent traits beyond increases in adiposity in this observational study in early female adolescents. Because disruptions of circadian rhythms are believed to lead to dysregulated energy homeostasis and not vice-versa, our findings highlight the need for sleep interventions in adolescence to help reduce the global burden of cardiometabolic ill health, especially in girls.

Obesity in children and adolescents: Overview of the diagnosis and management

Childhood obesity is one of the biggest public health challenges globally. It is associated with various adverse health consequences throughout life. Prevention and early intervention represent the most reasonable and cost-effective approaches. Considerable progress has been achieved in the management of obesity in children and adolescents; yet, implementation in the real world remains a challenge. This article aimed to present an overview of the diagnosis and management of obesity in children and adolescents.

Circadian Misalignment Impacts the Association of Visceral Adiposity With Elevated Blood Pressure in Adolescents

BACKGROUND

Although insufficient sleep has been shown to contribute to obesity-related elevated blood pressure, the circadian timing of sleep has emerged as a novel risk factor. We hypothesized that deviations in sleep midpoint, a measure of circadian timing of sleep, modify the association between visceral adiposity and elevated blood pressure in adolescents.

METHODS

We studied 303 subjects from the Penn State Child Cohort (16.2±2.2 years; 47.5% female; 21.5% racial/ethnic minority). Actigraphy-measured sleep duration, midpoint, variability, and regularity were calculated across a 7-night period. Visceral adipose tissue (VAT) was measured with dual-energy X-ray absorptiometry. Systolic blood pressure (SBP) and diastolic blood pressure levels were measured in the seated position. Multivariable linear regression models tested sleep midpoint and its regularity as effect modifiers of VAT on SBP/diastolic blood pressure levels, while adjusting for demographic and sleep covariables. These associations were also examined as a function of being in-school or on-break.

RESULTS

Significant interactions were found between VAT and sleep irregularity, but not sleep midpoint, on SBP (P interaction=0.007) and diastolic blood pressure (P interaction=0.022). Additionally, significant interactions were found between VAT and schooldays sleep midpoint on SBP (P interaction=0.026) and diastolic blood pressure (P interaction=0.043), whereas significant interactions were found between VAT and on-break weekdays sleep irregularity on SBP (P interaction=0.034).

CONCLUSIONS

A delayed and an irregular sleep midpoint during school and during free-days, respectively, increase the impact of VAT on elevated blood pressure in adolescents. These data suggest that deviations in the circadian timing of sleep contribute to the increased cardiovascular sequelae associated with obesity and that its distinct metrics require measurement under different entrainment conditions in adolescents.

Sleep variability and regularity as contributors to obesity and cardiometabolic health in adolescence

OBJECTIVE

Adolescence is a developmental stage of critical changes in sleep and its circadian timing when the contribution of abnormal sleep variability (amount) and sleep regularity (timing) to obesity and its associated adverse cardiometabolic health outcomes appears to increase. The aim of this study was to summarize findings from studies conducted in adolescents examining both sleep variability and regularity in relation to obesity and cardiometabolic health. Gaps in research and potential causal pathways that future studies should examine are highlighted.

RESULTS

Nightly deviations in sleep duration and sleep midpoint appear to contribute to the development of obesity and associated adverse cardiometabolic outcomes in youth. Studies show that increased sleep variability and irregularity are associated with obesity, decreased physical activity, dysregulated eating and inadequate diet, metabolic dysfunction, impaired cardiac autonomic balance, and elevated blood pressure in adolescents.

CONCLUSIONS

A stable circadian timing of sleep is essential to the overall physical well-being of youth. Emerging evidence supports that sleep variability and circadian misalignment, including sleep irregularity, contribute to adverse obesity-related health outcomes early on in adolescence. Future studies should focus on the underlying behavioral and biological mechanisms in the causal pathway between day-to-day deviations in the amount and timing of sleep and obesity.

Poor sleep pattern is associated with metabolic disorder during transition from adolescence to adulthood

OBJECTIVE

The purpose of this study was to investigate whether sleep pattern is associated with metabolic disorders among young adults.

METHODS

We measured sleep patterns using multiple sleep behaviors in an ongoing prospective cohort among college students (n = 1,151). At baseline, 729 college students provided fasting blood samples and human body morphological measurements for quantification of metabolic parameters. Then, 340 participants continued to take metabolic parameters measurements at a 2-year follow-up. Sleep patterns were defined by chronotype, sleep duration, insomnia, snoring, and daytime sleepiness. Metabolic scores were derived for four metabolic parameters including body mass index (BMI), waist circumference (WC), fasting blood sugar (FBG), and insulin. Multivariate linear regression model was applied to analyze the association between sleep pattern types and metabolic parameters and metabolic scores.

RESULTS

In the baseline survey, we found that a total of 41 (4.1%) participants had poor sleep patterns. Then, metabolic scores were significantly higher among college students with poor sleep patterns, compared with those who with healthy sleep patterns at baseline (1.00 ± 0.96 vs. 0.78 ± 0.72, p < 0.05) and 2-year follow-up (0.34 ± 0.65 vs. 1.50 ± 1.64, p < 0.05). After covariates were adjusted, poor sleep pattern (β = 0.22, 95% CI: 0.06~2.53, p = 0.001) was associated with elevated metabolic scores at the 2-year follow-up.

CONCLUSIONS

The elevated metabolic burden observed in college students with poor sleep patterns highlights the need to identify and address sleep problems in order to minimize the long-term impact on disease vulnerability.

Association between Sleep, Sedentary Time, Physical Activity, and Adiposity in Adolescents: A Prospective Observational Study

PURPOSE

This study aimed to examine the effects of substituting sedentary time with sleep or physical activity on adiposity in a longitudinal sample of adolescents.

METHODS

Adolescents (10-16 yr) were recruited for a prospective observational cohort. Parents and adolescents reported demographic characteristics and pubertal development. Accelerometry was used to measure sleep, physical activity, and sedentary time. Adiposity was quantified with imaging techniques. Isotemporal substitution modeling was conducted to examine the effect of substituting 10 min of sedentary time with sleep or differing intensities of physical activity. Results were stratified by sex and race and adjusted for covariates.

RESULTS

A total of 217 adolescents provided complete measures at both baseline and 2 yr later (58.1% White, 51.8% girls; 12.9 ± 1.9 yr at baseline). Sleep was negatively related to adiposity 2 yr later when considering other movement behaviors, but substituting baseline sedentary time with sleep was not related to future adiposity ( P > 0.05). In boys and non-White adolescents, substituting sedentary time with vigorous-intensity physical activity was related to lower adiposity 2 yr later ( P < 0.05). Substituting sedentary time for moderate- to vigorous-intensity physical activity was not associated with future adiposity.

CONCLUSIONS

Substituting sedentary time with vigorous-intensity physical activity was related to lower adiposity in later adolescence in certain groups. Opportunities to promote an adequate balance of sleep, sedentary time, and physical activity in all adolescents are encouraged for optimal development.

Objectively measured physical activity among treatment seeking children and adolescents with severe obesity and normal weight peers

Background

Treatment seeking children and adolescents with severe obesity often experience barriers to physical activity. Studies objectively measuring physical activity in this group and investigating explanatory factors for physical activity levels could inform clinical practice.

Objectives

This study aimed to compare objectively measured physical activity levels among treatment seeking children and adolescents with severe obesity and normal weight peers, and to investigate explanatory factors for time spent in moderate physical activity and vigorous physical activity among children and adolescents with severe obesity.

Methods

Children with severe obesity (n = 85) were matched 1:1 by age, gender, and the season for accelerometer measurements with normal weight peers (n = 85). Children wore accelerometers for seven consecutive days, yielding measures of physical activity, sleep duration and timing. Parents reported on screen time, parental body mass index and participation in organized sports.

Results

Children and adolescents with severe obesity spent significantly less time in moderate physical activity (12 min, p < 0.001) and vigorous physical activity (21 min, p < 0.001) per day compared to normal weight peers. No difference for time spent in sedentary activity was found between groups. For participants with severe obesity, age ≤12 years (p = 0.009) and participation in organized sports (p = 0.023) were related to more moderate physical activity, while age ≤12 years (p = 0.038) and early sleep timing (p = 0.019) were related to more vigorous physical activity.

Conclusion

Children and adolescents with severe obesity were less physically active than their normal weight peers. Factors related to more moderate and vigorous physical activity in children with severe obesity were lower age, participation in organized sports and earlier sleep timing.

Struggling with overweight or obesity in children - fathers' perceptions and experiences of contributing factors, role and responsibility

PURPOSE

The family environment is crucial in the prevention and treatment of childhood obesity; however, there is a lack of knowledge concerning paternal perceptions and experiences in childhood weight management. The aim of this study was to explore (i) perceptions of contributing factors to childhood overweight and obesity among fathers of children with overweight or obesity and (ii) the fathers' experiences of their parental role caring for a child with overweight or obesity.

METHOD

A qualitative content analysis was conducted of data from semi-structured in-depth interviews with eight Norwegian fathers of ten children and adolescents with overweight or obesity.

RESULTS

The analysis identified one overall theme; Feeling uncertain and struggling to understand their own responsibility for the child's overweight or obesity, which consists of two themes; 1)Trying hard to figure out the child's obesity as a complex interaction of factors and 2)Family functioning-negotiating roles and responsibility in parenthood.

CONCLUSION

Fathers must be met with understanding about their uncertainty and their struggle to understand their individual responsibility for their child's weight excess. It can be necessary to address the significance of family functioning, collaboration, responsibility within the familiy in addition to structural responsibility in clinical dialogues and counselling in order to help with weight management.

Integration of Time-Based Recommendations with Current Pediatric Health Behavior Guidelines: Implications for Obesity Prevention and Treatment in Youth

PURPOSE OF REVIEW

Youth-onset obesity is associated with negative health outcomes across the lifespan including cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, dyslipidemias, asthma, and several cancers. Pediatric health guidelines have traditionally focused on the quality and quantity of dietary intake, physical activity, and sleep.

RECENT FINDINGS

Emerging evidence suggests that the timing (time of day when behavior occurs) and composition (proportion of time spent allocated to behavior) of food intake, movement (i.e., physical activity, sedentary time), and sleep may independently predict health trajectories and disease risks. Several theoretically driven interventions and conceptual frameworks feature behavior timing and composition (e.g., 24 h movement continuum, circadian science and chronobiology, intermittent fasting regimens, structured day hypothesis). These literatures are, however, disparate, with little crosstalk across disciplines. In this review, we examine dietary, sleep, and movement guidelines and recommendations for youths ages 0-18 in the context of theoretical models and empirical findings in support of time-based approaches. The review aims to inform a unifying framework of health behaviors and guide future research on the integration of time-based recommendations into current quantity and quality-based health guidelines for children and adolescents.

Sleep dimensions are associated with obesity, poor diet quality and eating behaviors in school-aged children

Objectives

The aim of this cross-sectional study was to investigate the association between sleep dimensions (duration, patterns, and disturbances) with body mass index (BMI), diet quality, and eating behaviors in school-aged children. Additionally, we aimed to investigate whether obesogenic eating behaviors (higher food responsiveness, lower satiety responsiveness, and less slowness in eating) and poor diet quality could mediate the potential association between sleep and obesity in school-aged children.

Materials and methods

For all participants (n = 588 children, age 5–12 years; 51% girls) we evaluated: sleep dimensions, BMI, diet quality, eating behaviors (food responsiveness, satiety responsiveness and slowness in eating). Linear regression models were used to test associations between exposure and outcome variables. Additionally, path analysis was conducted to test whether eating behaviors mediated the relationship between sleep and obesity.

Results

Shorter sleep duration (β = −0.722, p = 0.009) and greater sleep disturbances (β = 0.031, p = 0.012) were significantly associated with BMI. Additionally, we observed that diet quality was significantly associated with sleep duration (β = 0.430, p = 0.004), the midpoint of sleep (β = −0.927, p < 0.001), and sleep disturbances (β = −0.029, p < 0.001). Among other findings, greater sleep disturbances were associated with food responsiveness (β = 0.017, p < 0.001), satiety responsiveness (β = 0.015, p < 0.001), and slowness in eating (β = 0.012, p < 0.001). Importantly, food responsiveness was found as significant mediator of the relationship between sleep and BMI (R = 0.427, R² = 0.182, p < 0.001).

Conclusions

Late sleep patterns, short sleep duration, and greater sleep disturbances are significantly related with what and how school-aged children eat. Importantly, poor diet quality was significantly related to all three sleep dimensions, while eating behaviors had a significant relationship with greater sleep disturbances. These findings may be relevant to the development of behavioral targets to prevent childhood obesity, including sleep hygiene guidelines as a strategy to improve children's eating habits, as well as their BMI.

The Current Prevalence of Underweight, Overweight, and Obesity Associated with Demographic Factors among Pakistan School-Aged Children and Adolescents-An Empirical Cross-Sectional Study

Purpose: This study investigated the most recent estimates of underweight, overweight, and obesity prevalence in Pakistani school-aged children and adolescents. Methods: A cross-sectional study was conducted using a convenience random clustered sampling approach with 3,551 Pakistani school children aged 9 to 17 years from 52 schools throughout seven districts in central Punjab province. The CDC US 2000 was used to define underweight (BMI < 5th percentile), overweight (85th ≤ BMI < 95th percentile), and obesity (95th percentile ≤ BMI) for different school grade cohorts (primary, middle, secondary, and higher secondary schools). As a trend test, the Chi-square test was used. A Spearman correlation analysis (r) was used to determine the correlations between demographic variables and weight status. A regression analysis was conducted to explore the predictive power of demographic factors in relation to body weight. Results: In Pakistani school-aged children and adolescents, the prevalence of underweight, normal weight, overweight, and obesity was 21.9%, 66.9%, 5.8%, and 5.4%, respectively. Significant correlations with body weight status were shown for individual demographic parameters (age, gender, school type, and school grade). Children in urban areas were more likely to be underweight, overweight, or obese than those in rural areas. Boys were found to have a lower BMI than girls. Accordingly, more boys than girls were underweight (odds ratio (OR) = 1.57, 95% CI: 1.33-1.85) and more girls had a higher risk of obesity than boys (OR = 1.39, 95% CI: 1.03-1.86). Lower grades showed more underweight (OR = 1.66, 95% CI: 1.39-1.99) whereas higher grades showed a higher risk of obesity (OR = 1.91, 95% CI: 1.41-2.57). Conclusions: In Pakistani school-aged children and adolescents, underweight, overweight, and obesity were prevalent. Compared with studies from 2011, the risk of overweight and obesity in Pakistan has decreased. However, this may also be due to the fact that students in Pakistan have a lower BMI compared to other countries. This issue has also been seen in the present study and is confirmed here by the high number of cases of underweight students. Future research studies should look into additional weight status correlates and factors. To evaluate the association between weight status and behavioral and other health variables, future research should use longitudinal or interventional designs.

Associations of Sleep-Related Outcomes with Behavioral and Emotional Functioning in Children with Overweight/Obesity

OBJECTIVE

To evaluate the associations of parent-reported sleep-disordered breathing (SDB) and device-assessed sleep behaviors with behavioral and emotional functioning in pediatric patients with overweight/obesity.

STUDY DESIGN

A total of 109 children with overweight/obesity (mean age, 10.0 ± 1.1 years) were included in this cross-sectional study. We used the Spanish version of the Pediatric Sleep Questionnaire (PSQ) to assess SDB and its subscales (ie, snoring, daytime sleepiness, and inattention/hyperactivity). Device-assessed sleep behaviors (ie, wake time, sleep onset time, total time in bed, total sleep time, and waking after sleep onset) were estimated using wrist-worn accelerometers. We used the Behavior Assessment System for Children, second edition to assess behavioral and emotional functioning (ie, clinical scale: aggressiveness, hyperactivity, behavior problems, attention problems, atypicality, depression, anxiety, retreat, and somatization; adaptive scale: adaptability, social skills, and leadership).

RESULTS

SDB was positively associated with all clinical scale variables (all β > 0.197, P ≤ .041) and with lower adaptability and leadership (all β < -0.226, P < .021). Specifically, the PSQ subscale relating to daytime sleepiness was associated with higher attention problems, depression, anxiety, and retreat (all β > 0.196, P ≤ .045) and lower adaptability (β = -0.246, P = .011). The inattention/hyperactivity subscale was significantly associated with the entire clinical and adaptive scales (all β > |0.192|, P ≤ .046) except for somatization. The snoring subscale and device-assessed sleep behaviors were not related to any behavioral or emotional functioning variables.

CONCLUSIONS

Our study suggests that SDB symptoms, but not device-assessed sleep behaviors, are associated with behavioral and emotional functioning in children with overweight/obesity. Specifically, daytime sleepiness, a potential SDB symptom, was related to higher attention problems, depression, anxiety, and retreat and lower adaptability.

Social Jetlag Is Associated With Impaired Metabolic Control During a 1-Year Follow-Up

Previous studies have identified social jetlag (SJL) as a risk factor for non-communicable chronic diseases (NCCDs), but its association with metabolic control over time is unclear in the literature. Therefore, we examined the influence of SJL on metabolic parameters and blood pressure (BP) in patients with NCCDs over a 1-year follow-up. This retrospective, longitudinal study included 625 individuals (age: 56.0 +12.0 years; 76% female) with NCCDs [type 2 diabetes mellitus (TD2), systemic arterial hypertension (SHA), obesity, or dyslipidemia]. SJL was calculated based on the absolute difference between mid-sleep time on weekends and weekdays. Current metabolic parameters and BP of the patients were compared with data from a year prior. Generalized estimating equations (GEE) and multiple linear regression analyses were used to examine the association among SJL, metabolic parameters, and BP. Multiple linear regression analyses adjusted for confounders showed that SJL was positively associated with the delta difference of fasting glucose (β = 0.11, p = 0.02) and triglyceride levels (β = 0.09, p = 0.04) among all subjects with NCCDs, and with fasting glucose (β = 0.30, p = 0.0001) and triglyceride levels (β = 0.22, p = 0.01) in the TD2 group. GEE analysis demonstrated an isolated effect of SJL on diastolic BP. High SJL impaired clinical and metabolic control in individuals with NCCDs, leading to a worse profile after a 1-year follow-up, particularly among type II diabetics.

Independent associations of sleep timing, duration and quality with adiposity and weight status in a national sample of adolescents: The UK Millennium Cohort Study

Short sleep appears to elevate obesity risk in youth; however, sleep is a multidimensional construct, and few studies have investigated parameters beyond duration. The objective of this study was to investigate if sleep onset time, duration, latency and night waking frequency are independently associated with adiposity and weight status in UK adolescents. This was a cross-sectional observational study of 10,619, 13-15 years olds. Adjusted linear and logistic regressions were used to investigate associations of self-reported sleep characteristics with adiposity markers (body mass index z-score and percent body fat) and weight status. Compared with a sleep onset before 10pm, later sleep timing was associated with higher adiposity and higher likelihood of overweight and obesity in boys (after midnight, odds ratio [95% confidence interval]: 1.76 [1.19-2.60]) and girls (between 11pm and 11:59pm: 1.36 [1.17-1.65]). Sleeping ≤ 8 hr, compared with > 9-10 hr, was associated with higher odds of overweight and obesity in both sexes (boys: 1.80 [1.38-2.35]; girls: 1.38 [1.06-1.79]), and so too was sleeping > 10 hr in girls (1.31 [1.06-1.62]), indicating evidence for a U-shaped association. Also in girls, compared to a sleep latency of 16-30 min, sleep latencies ≥ 46 min were associated with higher adiposity (46-60 min, beta coefficient [95% confidence interval], percent body fat: 1.47 [0.57-2.36]) and higher likelihood of overweight and obesity (46-60 min: 1.39 [1.05-1.83]), and often as opposed to never waking in the night was associated with higher adiposity (body mass index z-score: 0.24 [0.08-0.41]; percent body fat: 1.44 [0.44-2.44]). Sleep duration and timing in both sexes, and sleep quality in girls, appear to be independently associated with adiposity and weight status in adolescence, and may be important targets for obesity prevention.

Social jetlag is associated with obesity-related outcomes in 9-11-year-old children, independent of other sleep characteristics

INTRODUCTION

Social jetlag has been reported to predict obesity-related indices, independent of sleep duration, with associations in female adolescents but not males. However, such sex-specific relationships have not been investigated in pre-adolescents.

OBJECTIVES

To examine: (i) the relationships between sleep characteristics, including social jetlag, and obesity-related outcomes during childhood, and (ii) whether these relationships are moderated by sex.

METHODS

This cross-sectional study included 381 children aged 9-11 years (49.6% female). Average sleep duration, social jetlag, and physical activity were assessed via wrist-worn accelerometry. Sleep disturbances were quantified from the Children's Sleep Habits Questionnaire. Obesity-related outcomes included age-specific body mass index Z-scores (zBMI) and waist-to-height ratio. Additionally % fat, total fat mass, and fat mass index were assessed via bioelectrical impedance analysis. Linear mixed models that nested children within schools were used to identify relationships among sleep characteristics and obesity-related outcomes.

RESULTS

Positive associations between social jetlag with zBMI, % fat, and fat mass index were seen in univariable and unadjusted multivariable analyses. Following adjustments for known confounders, social jetlag remained significantly associated with zBMI (β = 0.12, p = 0.013). Simple slopes suggested a positive association in girls (β = 0.19, p = 0.006) but not in boys (β = 0.03, p = 0.703).

CONCLUSIONS

Obesity prevention efforts, particularly in girls, may benefit from targeted approaches to improving the consistency of sleep timing in youth.

Use of a social jetlag-mimicking mouse model to determine the effects of a two-day delayed light- and/or feeding-shift on central and peripheral clock rhythms plus cognitive functioning

Social jetlag (SJL) is defined as the discrepancy between social and biological rhythms and calculated by the difference between the midpoint of sleep time on working-days and free-days. Previous human and mouse studies showed SJL is positively related to evening chronotype and significantly related to smoking habit, cardiovascular risk, cognitive ability, and that SJL-mimicking conditions, simulating the real lifestyle situation of SJL in many humans, disrupt the regularity of estrous cycles of female animals. The effects of SJL-mimicking conditions on circadian rhythms and cognitive function and the reasons why the discrepancy between social and biological rhythms is involved in SJL have not yet been investigated. Therefore, in this study, we utilized a mouse model of SJL-mimicking conditions - 6-hour delayed-light/dark (LD) conditions for 2 days and normal-LD conditions for the following 5 days - applied for several weeks during which biological rhythms were monitored. Circadian rhythms of central and peripheral clocks and metabolism of the mice under the SJL-mimicking condition were always delayed for 2-3 hours compared with those under the normal-LD condition. Moreover, SJL-mimicking conditions impaired their cognitive function using a novel object recognition test. Only the delayed timing of either the light phase of the LD or of feeding for 2 days, comparable to the free-days situation of humans, delayed the circadian staging of rhythms the following 5 days. Furthermore, sleep deprivation during the early mornings for 5 days, which is comparable to early rise times experienced by humans on working-days and does affect the staging of circadian rhythms (circadian misalignment schedule), delayed the locomotor activity rhythms the next 2 days, comparable to free-days in humans, which is similar to the lifestyle rhythm of the evening chronotype. Our results demonstrated that the circadian misalignment schedule for 5 days changed the locomotor activity rhythms the following 2 days to the evening chronotype, that light- and/or feeding-shift conditions for 2 days exacerbate SJL, and that SJL-mimicking conditions delay the metabolic rhythm and cause cognitive impairment.

On the influence of the day of the week on objective and self-rated sleep quality of adults

Background and objective

The extent to which adult sleep varies depending on the day of the week has not yet been systematically investigated with electroencephalography (EEG) data. Whether such effects exist and whether they are related to age, gender, and employment status was retrospectively analyzed based on data from an experimental double-blind cross-over study in which effects of electromagnetic fields of a cell phone base station on the sleep of a general rural population had been examined.

Methods

The sleep of 397 adults (age 45.0 ± 14.2 years, range 18–81 years; 50.9% women) from ten different rural German villages was recorded for 12 nights with ambulatory devices. Self-reported sleep quality was recorded in morning and evening protocols. Friedman tests were used for statistical analysis of the comparison between the days, and the Kruskal–Wallis and Mann–Whitney U tests were used for pairwise comparisons of independent parameters between groups.

Results

For the present analysis, data from 335 participants were considered. Overall, the differences between nights were small and the quality of sleep was good. Three of the five objective and all six self-rated sleep parameters differed significantly between the days of the week. While the objective and the self-estimated total sleep time were longest on Sunday nights, the qualitatively poorest values occurred on Monday nights. People who worked fulltime had the longest sleep latencies on Sunday nights. Friday nights were rated the best.

Conclusion

The objective and self-rated sleep quality varied relatively little in a rural adult population over the course of the week, being worst on Monday nights and best on Friday nights.