From sleep duration to childhood obesity--what are the pathways?

Association between sleep duration and serum neurofilament light chain levels among adults in the United States

Background

Neurofilaments are neuron specific skeleton proteins maintaining axon transduction speed, leaked into cerebrospinal fluid and serum after axonal injury or neuron death. Sleep duration change has long related to many health issues but lack laboratory examination.

Methods

This study enrolled total 10,175 participants from 2013 to 2014 National Health and Nutrition Examination Survey and used a multi-variable linear model to analyze the relationship between sleep duration and serum neurofilament light chain (sNfL) level.

Results

There was a fixed relationship between sleep duration and sNfL level (β = 0.65, p = 0.0280). After adjusted for covariates, this relationship still (β = 0.82, p = 0.0052). Segmented regression showed that the turning point of sleep duration was 7 h 1 h decrease in sleep duration was significantly associated with -1.26 higher sNfL level (95 % CI: 2.25, -0.28; p = 0.0115) when sleep duration <7 h; however, 1 h increase in sleep duration was significantly associated with 3.20 higher sNfL level (95 % CI: 2.13, 4.27; p < 0.0001) when sleep duration >7 h. Furthermore, the stratified analysis indicated that the associations between sleep duration and sNfL level were stronger among those normal body mass index and trouble sleeping (p-interaction <0.0001 and 0.0003).

Conclusion

In summary, there was a J-shaped relationship between sleep duration and sNfL level in the United States of America representative group, these may suggest that extreme sleep duration can be deleterious judged by sNfL level. And still need large cohort study to determine the accurate relationship, and cluster analysis to infer the nervous disease connected with extreme sleep duration.

Sleep Duration and Metabolic Syndrome among Early Adolescents-A Cross-Sectional Study in Khartoum State, Sudan

Numerous studies have reported that sleep disorders are linked to poor health outcomes. However, studies on these associations in children and adolescents in an African context are limited. The aim of the present study was to analyze the relationship between sleep duration and the presence of metabolic syndrome among early adolescents in Sudan. Methods: A cross-sectional study was conducted on participants aged 10-15 years in Khartoum State, Sudan. Metabolic syndrome (MetS) was diagnosed by increased waist circumference and the presence of two or more metabolic abnormalities (triglycerides [TG], high-density lipoproteins [HDL-C], blood pressure [BP], and fasting plasma glucose [FBG]). Short sleep duration was defined based on National Sleep Foundation (NSF) classification. Data were collected by physical examinations, biochemical analyses, and self-developed standardized questionnaires. Data were analyzed with IBM SPSS Statistics Version 24. A generalized additive model (GAM) was used for the smoothing function between sleep duration and MetS. p < 0.05 was considered as significant. Results: The prevalence of MetS and short sleep among early adolescents aged 10-15 years in Sudan was 2.3% and 55.0%, respectively. A higher prevalence of short sleep was found among overweight and obese participants (p < 0.05). The prevalence of MetS among short sleepers was 2.8%. Binary logistic regression analysis showed that male short sleepers had higher odds of having MetS compared to female short sleepers. The relationship between short sleep and low HDL-C in boys and between short sleep and high TG in girls was statistically significant. The highest risk of MetS was observed at less than 6.5 h of sleep per night. Conclusions: Short sleep duration was significantly associated with overweight/obesity in the total population and with low HDL-C in boys and high triglycerides in girls. A nonlinear curve pattern was observed between sleep duration and prevalence of MetS. Longitudinal studies are needed to further determine the causal relationship between sleep habits and MetS and its components.

Identification of positive parenting practices among parents of young children living in low-income and racially, ethnically, and culturally diverse households

Using the positive deviance approach, the purpose of this study was to identify parent feeding practices that might be protective against early childhood obesity among children with lower weight status (BMI percentile ≥5th-<85th) relative to higher weight status (BMI percentile ≥85th). Qualitative interviews were conducted with 71 parents of children aged 2-5 years old (48% girls) enrolled in the Minnesota Special Supplemental Nutrition Program for Women Infants and Children (WIC). Children were identified as having lower weight status (defined as 'positive deviants') (n = 36) or 'higher weight status' (n = 35), and were African American [n = 22], Hispanic [n = 23], or Hmong [n = 26]). Parents were asked about approaches to child feeding and health- and weight-related practices. Findings indicated that relative to caregivers of children with higher weight status, parents of children identified as positive deviant were more likely to report having a consistent routine for providing meals, using a guided choices approach, serving small portions of food during mealtimes, and trusting their child hunger and satiety cues. Moreover, parents of children identified as positive deviant were more likely to promote healthful eating and physical activity engagement and implement clear rules and limits for screen time than parents of children with higher weight status. Results suggest specific parent feeding behaviors and health-related practices that may influence child weight status among children living in low-income and racialized households. The findings of this study also provide research evidence and support the tenets of the Satter Division of Responsibility in Feeding framework. Parenting practices and strategies among parents of children identified as positive deviant are expected to be feasible and should be explored and communicated in future interventions to support age- and sex-recommended weight and health-related outcomes among young children to promote health equity.

Causative Mechanisms of Childhood and Adolescent Obesity Leading to Adult Cardiometabolic Disease: A Literature Review

The past few decades have shown a worrisome increase in the prevalence of obesity and its related illnesses. This increasing burden has a noteworthy impact on overall worldwide mortality and morbidity, with significant economic implications as well. The same trend is apparent regarding pediatric obesity. This is a particularly concerning aspect when considering the well-established link between cardiovascular disease and obesity, and the fact that childhood obesity frequently leads to adult obesity. Moreover, most obese adults have a history of excess weight starting in childhood. In addition, given the cumulative character of both time and severity of exposure to obesity as a risk factor for associated diseases, the repercussions of obesity prevalence and related morbidity could be exponential in time. The purpose of this review is to outline key aspects regarding the current knowledge on childhood and adolescent obesity as a cardiometabolic risk factor, as well as the most common etiological pathways involved in the development of weight excess and associated cardiovascular and metabolic diseases.

Genome-wide conditional association study reveals the influences of lifestyle cofactors on genetic regulation of body surface area in MESA population

Body surface area (BSA) is an important trait used for many clinical purposes. People's BSA may vary due to genetic background, race, and different lifestyle factors (such as walking, exercise, reading, smoking, transportation, etc.). GWAS of BSA was conducted on 5,324 subjects of four ethnic populations of European-American, African-American, Hispanic-American, and Chinese-American from the Multi-Ethnic Study of Atherocloris (MESA) data using unconditional and conditional full genetic models. In this study, fifteen SNPs were identified (Experiment-wise PEW < 1×10-5) using unconditional full genetic model, of which thirteen SNPs had individual genetic effects and seven SNPs were involved in four pairs of epistasis interactions. Seven single SNPs and eight pairs of epistasis SNPs were additionally identified using exercise, smoking, and transportation cofactor-conditional models. By comparing association analysis results from unconditional and cofactor conditional models, we observed three different scenarios: (i) genetic effects of several SNPs did not affected by cofactors, e.g., additive effect of gene CREB5 (a≙ -0.013 for T/T and 0.013 for G/G, -Log10 PEW = 8.240) did not change in the cofactor models; (ii) genetic effects of several SNPs affected by cofactors, e.g., the genetic additive effect (a≙ 0.012 for A/A and -0.012 for G/G, -Log10 PEW = 7.185) of SNP of the gene GRIN2A was not significant in transportation cofactor model; and (iii) genetic effects of several SNPs suppressed by cofactors, e.g., additive (a≙ -0.018 for G/G and 0.018 for C/C, -Log10 PEW = 19.737) and dominance (d≙ -0.038 for G/C, -Log10 PEW = 27.734) effects of SNP of gene ERBB4 was identified using only transportation cofactor model. Gene ontology analysis showed that several genes are related to the metabolic pathway of calcium compounds, coronary artery disease, type-2 Diabetes, Alzheimer disease, childhood obesity, sleeping duration, Parkinson disease, and cancer. This study revealed that lifestyle cofactors could contribute, suppress, increase or decrease the genetic effects of BSA associated genes.

From conception to infancy - early risk factors for childhood obesity

Maternal lifestyle during pregnancy, as well as early nutrition and the environment infants are raised in, are considered relevant factors for the prevention of childhood obesity. Several models are available for the prediction of childhood overweight and obesity, yet most have not been externally validated. Moreover, the factors considered in the models differ among studies as the outcomes manifest after birth and depend on maturation processes that vary between individuals. The current Review examines and interprets data on the early determinants of childhood obesity to provide relevant strategies for daily clinical work. We evaluate a selection of prenatal and postnatal factors associated with child adiposity. Actions to be considered for preventing childhood obesity include the promotion of healthy maternal nutrition and weight status at reproductive age and during pregnancy, as well as careful monitoring of infant growth to detect early excessive weight gain. Paediatricians and other health-care professionals should provide scientifically validated, individual nutritional advice to families to counteract excessive adiposity in children. Based on systematic reviews, original papers and scientific reports, we provide information to help with setting up public health strategies to prevent overweight and obesity in childhood.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

DRKS-ID: DRKS00000494 .

Association of sleep duration with metabolic syndrome and its components in children and adolescents; a propensity score-matched analysis: the CASPIAN-V study

OBJECTIVE

This study aims to evaluate the association of sleep duration with metabolic syndrome (MetS) and its components in a pediatric population.

METHODS

This multi-centric cross-sectional study was conducted in 2015 in 30 provinces of Iran. Participants consisted of 4200 school students aged 7-18 years, studied in a national school-based surveillance program (CASPIAN-V). Physical examinations and laboratory tests were performed using standard protocols. The analysis was conducted based on the propensity score matching and conditional logistic regression was used to evaluate the association of short sleep (less than 8 h a day) and the onset of sleep with MetS and its components. Results of conditional logistic regression was reported as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Overall, 3843 of participants completed the survey (response rate: 91.5%). Their mean (SD) age was 12.3 (3.2) years and 50.6% were boys. In the multivariate model, individuals who slept less than 8 h a day had significantly higher odds of MetS (OR 2.05, 95% CI 1.19-3.63) and high blood pressure (BP) (OR 1.46, 95% CI 1.04-2.06). Association between short sleep duration with other MetS components (including abdominal obesity, hypertriglyceridemia, hyperglycemia, and low levels of high-density lipoprotein-cholesterol was not statistically significant (P > 0.05). Moreover, association between the onset of sleep with MetS and its components was not statistically significant (P > 0.05).

CONCLUSION

Short sleep duration is associated with increased risk of MetS and high BP in children and adolescents. The clinical impact of current findings should be assessed in future longitudinal studies.

The relationship between hours of sleep, screen time and frequency of food and drink consumption in Spain in the 2011 and 2013 ALADINO: a cross-sectional study

BACKGROUND

The frequency of intake of food and beverages depends on a number of ill-defined behaviour patterns. The objectives of this study were to evaluate the effects of screen time and sleep duration on food consumption frequency, and to describe frequencies and types of food consumption according to BMI category and parents' level of education.

METHODS

We studied 6287 and 2806 children drawn from the 2011 and 2013 cross-sectional ALADINO studies respectively. Data were collected on number of hours of sleep, screen time, and weekly frequency of consumption of 17 food groups. Weight status was measured, and information was also collected on parents' educational level. Average food consumption frequencies were calculated by reference to hours of sleep and hours of screen time, and were defined as ≥4 times or <4 times per week (once per week for soft drinks and diet soft drinks). Differences in frequency were evaluated for screen times of more and less than 2 h per day, and for sleep durations longer or shorter than the daily average. We fitted logistic regression models to evaluate the independent association between screen exposure and hours of sleep on the one hand, and food consumption frequency on the other.

RESULTS

Consumption of fruit and vegetables was lower among children who had parents with no formal or only primary school education. High levels of screen time were associated with a greater frequency of consumption of energy-dense, micronutrient-poor products and a lower frequency of consumption of fruit and vegetables. Sleeping a sufficient number of hours was associated with a higher consumption of fruit and vegetables. The results for 2011 were concordant with those for 2013.

CONCLUSIONS

If efforts to ensure healthier eating habits among children are to be at all successful, they should focus on promoting a sufficient amount of sleep for children, limiting the time they spend watching television and/or playing with computers or video games, and educating parents accordingly.

Sleep Duration and Quality: Impact on Lifestyle Behaviors and Cardiometabolic Health: A Scientific Statement From the American Heart Association

Sleep is increasingly recognized as an important lifestyle contributor to health. However, this has not always been the case, and an increasing number of Americans choose to curtail sleep in favor of other social, leisure, or work-related activities. This has resulted in a decline in average sleep duration over time. Sleep duration, mostly short sleep, and sleep disorders have emerged as being related to adverse cardiometabolic risk, including obesity, hypertension, type 2 diabetes mellitus, and cardiovascular disease. Here, we review the evidence relating sleep duration and sleep disorders to cardiometabolic risk and call for health organizations to include evidence-based sleep recommendations in their guidelines for optimal health.

Longitudinal associations of lifestyle factors and weight status with insulin resistance (HOMA-IR) in preadolescent children: the large prospective cohort study IDEFICS

Background

This study investigates prospective associations of anthropometrical and lifestyle indices with insulin resistance (IR) in European children from the IDEFICS cohort. Insulin resistance (IR) is a growing concern in childhood obesity and a central aspect of the metabolic syndrome (MS). It most likely represents the link between obesity and type 2 diabetes.

Methods

This longitudinal study included 3348 preadolescent children aged 3 to 10.9 years from 8 European countries who were observed from 2007/2008 to 2009/2010. The main outcome measure in the present analysis is HOMA-IR (homeostasis model assessment as a common proxy indicator to quantify IR) at follow-up and in its longitudinal development. Anthropometrical measures and lifestyle indices, including objectively determined physical activity, were considered, among others factors, as determinants of IR. Prospective associations between IR at follow-up and anthropometrical and lifestyle indices were estimated by logistic regression models.

Results

Country-specific prevalence rates of IR in the IDEFICS cohort of European children showed a positive trend with weight category. Prospective multivariate analyses showed the strongest positive associations of IR with BMI z-score (OR = 2.6 for unit change from the mean, 95 % CI 2.1–3.1) and z-score of waist circumference (OR = 2.2 for unit change from the mean, 95 % CI 1.9–2.6), which were analysed in separate models, but also for sex (OR = 2.2 for girls vs. boys, 95 % CI 1.5–3.1 up to OR 2.5, 95 % CI 1.8–3.6 depending on the model), audio-visual media time (OR = 1.2 for an additional hour per day, 95 % CI 1.0–1.4 in both models) and an inverse association of objectively determined physical activity (OR = 0.5 for 3^rd compared to 1^st quartile, 95 % CI 0.3–0.9 in both models). A longitudinal reduction of HOMA-IR was accompanied with a parallel decline in BMI.

Conclusions

This study is, to our knowledge, the first prospective study on IR in a preadolescent children’s population. It supports the common hypothesis that overweight and obesity are the main determinants of IR. Our data also indicate that physical inactivity and a sedentary lifestyle are likewise associated with the development of IR, independent of weight status. The promotion of physical activity should thus be considered as an equal option to dietary intervention for the treatment of IR in the paediatric practice.

Sleep duration and treatment compliance: a population-based cross-sectional study of hypertensive patients in Bangladesh

BACKGROUND

Treatment with appropriate medication is a key factor to control hypertension and reduce the associated risk of complications. However, compliance with treatment is often sub-optimal, especially in developing countries. Our aim in this cross-sectional study is to investigate whether there is an association between sleep duration and treatment compliance among skilled professionals who are experiencing hypertension.

METHODS

A questionnaire was given to all skilled professionals who are found hypertensive in an organization of Bangladesh. To assess treatment compliance, questions on self-reported compliance test were used. We collected information on self-reported short sleep duration (6 h or less) along with socio-demographic factors and clinical conditions of the subjects.

RESULTS

Sleep duration is associated with compliance with treatment among hypertensive skilled professionals. We found overall associations of sleep duration (odds ratio (OR) 3.77, confidence interval 1.44-10.83) with treatment compliance among hypertensive patients. In addition, body mass index (OR 1.19), marital status (OR 0.16) and duration of having hypertension are found significant factors for non-compliance with treatment.

CONCLUSION

There is an association between sleep duration and treatment compliance among the hypertensive patients. However, the study is conducted with a small group of skilled professionals from an organization and it is important to include multi-centers to validate the conclusion.

Sleep quality and duration is related with diet and obesity in young adolescent living in Sicily, Southern Italy

The aim of this study was to evaluate the association between sleeping habits, Mediterranean diet pattern, and weight status in an adolescent population. The sample consisted of 1586 individuals aged 11–14 years attending 15 secondary schools of Sicily, Southern Italy. School were randomly selected and the data collected during two school years. Anthropometric data was collected and body composition was assessed by bioelectrical impedance analysis. Demographic information, sleep duration, pediatric daytime sleepiness questionnaire (PDSS), physical activity and dietary habits (including adherence to the Mediterranean Diet using the KIDMED score) were further collected. The mean age was 12±0.7 and about 24% were overweight and obese. An inverse correlation between total sleep time and body mass index (β=−0.829, P=0.021), fat mass (β=−0.526, P=0.025), and waist circumference (β=−0.426, P=0.045) was found. Similar results were found for weekdays sleep time, while an inverse relationship was found with PDSS score. Adherence to Mediterranean Diet was higher in under/normal weight adolescent with a significant linear association between the KIDMED score and the PDSS, weekdays sleep time and total sleep time. Sleep duration was also associated positively with fruits and vegetable intake and negatively with sweet and snack consumption and eating outside habits. Short sleep duration and poor sleep were associated with an increase in BMI and fat mass as well as to unhealthy eating behaviors. These findings suggest that sleep patterns could be a potential target for obesity prevention programs in young adolescence.

Duration of sleep at 3 years of age is associated with fat and fat-free mass at 4 years of age: the Southampton Women's Survey

Many studies have shown that shorter sleep duration in childhood is associated with higher body mass index (BMI), and have proposed that it is due to an effect of sleep on adiposity. There is little evidence about the association of sleep with fat-free mass. This study examined the association between child's sleep duration at age 3 years and fat and fat-free mass at 4 years of age in a prospective cohort study of 302 boys and 285 girls. Study participants were taking part in the Southampton Women's Survey, a longitudinal study of mothers and children from preconception onwards. Total sleep duration at age 3 years was derived from parental report of night sleep and nap duration. Body composition was assessed by Dual-energy X-ray Absorptiometry (DXA) at 4 years. Mean total sleep duration was 11.5 hours. In linear regression analyses, adjusted for potentially confounding factors (maternal educational attainment, prepregnancy BMI, smoking during pregnancy, child's gestational age at birth, age at DXA, sex, age last breastfed, dietary quality at 3 years, TV watching and hours actively on the move and parental social class), shorter sleep in hours was associated with higher BMI (kg/m(2) ) [β: -0.2340, 95% confidence interval (CI): -0.373 to -0.096], a greater fat mass index (kg) (β: -0.1182, 95% CI: -0.218 to -0.018) and a greater fat-free mass index (kg) (β: -0.100, 95% CI: -0.185 to -0.015). Previous research suggested that the association between shorter sleep and higher body mass index is due to an effect on adiposity. Our findings are novel, suggesting that the relationship between sleep and BMI is also determined by an effect on muscle.

Association between sleep duration and obesity is age- and gender-dependent in Chinese urban children aged 6-18 years: a cross-sectional study

Background

Information on the relationship between sleep duration and obesity among children in urban Guangzhou, China is limited. This study aims to examine the relationship between sleep duration and obesity in children aged 6–18 years.

Methods

The sample consisted of 11,830 children aged 6–18 years. The children were randomly selected from 13 schools in three urban districts of Guangzhou. The study was conducted from September to November 2013. The height and weight of the children were measured. Adiposity status was estimated using body mass index and according to the cut point in China criteria. In the structured questionnaire, children reported daily sleep hours (less than 7 h, 7–9 h and more than 9 h), weekly food intake amount (including vegetables, fruit, sugar beverages and meat), physical activity and sedentary time. A caretaker would answer the questionnaire on behalf of a child aged below nine.

Results

A total of 8,760 children (49.0 % boys) completed the study. The prevalence of obesity was 8.4 % (9.8 % in boys and 5.7 % in girls). Adjusted for age, diet and physical activity/sedentary behaviour, the odds ratio (OR) for obesity comparing sleeping <7 h (short sleep duration, SSD) with ≥9 h (long sleep duration, LSD) was 0.70 (95 % CI: 0.69–0.72) among boys and 1.73 (95 % CI: 1.71–1.74) among girls. Stratified by age, OR for boys aged 6–12 years comparing SSD with LSD was 0.60 (95 % CI: 0.55–0.66); by contrast, OR was 1.33 (95 % CI: 1.30–1.37) for boys aged 13–18 years.

Conclusion

Short sleep duration is associated with increased chances of obesity among girls and 13- to 18-year-old boys, but the chances of obesity are decreased among 6- to 12-year-old boys. Age and gender should be regarded as specific characteristics for the effects of short sleep on obesity.

[Factors associated with eating disorders in students of the University of Littoral Côte d'Opale]

AIMS

Our study aimed to observe the rate of eating disorders in first year public health students (allied medical and sports) of the University of the Littoral Opal Coast (ULCO) using the SCOFF-F (Sick, Control, One, stone, Fat, Food; French version) questionnaire and to compare morphological characteristics, level of physical condition, level of physical activity and sleep quality.

METHODS

Overall 642 subjects (459 women and 183 men) aged 22years (20.9±4.9years) participated in this study (Universanté-CEMHaVi). Weight, height, and fat mass were measured, and waist-to-hip ratio and body mass index (BMI) were calculated. The level of physical condition was evaluated using several physical tests: Leger and Boucher (20m) and shuttle run (4×10m), Sargent-test and handgrip strength. The SCOFF-F questionnaire followed by a clinical maintenance conducted by a professional was used to detect eating disorders. Several other questionnaires were used to evaluate the physical activity level; General Practice Assessment Questionnaire (GPAQ) and wellness. Sleep quality index was evaluated using Pittsburgh Sleep Quality Index (PSQI).

RESULTS

SCOFF-F was positive in 24.2% of women and 10.2% of men. In women, there were no significant differences between those who had a positive SCOFF-F screening and those who had a negative SCOFF-F screening regarding age, height, waist-to-hip ratio, level of physical condition measured and level of physical activity evaluated. However, significant differences were found between women who had a positive SCOFF-F screening and women who had a negative SCOFF-F screening regarding sleep quality, well-being score, BMI and fat mass. In men, significant differences were found between those who had a positive SCOFF-F screening and those who had a negative SCOFF-F screening regarding BMI and fat mass.

CONCLUSION

This study suggests that in both sexes, having a positive SCOFF-F screening is associated with higher BMI. In women, the increase in BMI and the perturbations in sleep quality and well-being score may indicate bulimia nervosa. The definition of a panel of possible factors associated with eating disorders can help in screening and early detection of eating disorders.

WHO European Childhood Obesity Surveillance Initiative: associations between sleep duration, screen time and food consumption frequencies

BACKGROUND

Both sleep duration and screen time have been suggested to affect children's diet, although in different directions and presumably through different pathways. The present cross-sectional study aimed to simultaneously investigate the associations between sleep duration, screen time and food consumption frequencies in children.

METHODS

The analysis was based on 10 453 children aged 6-9 years from five European countries that participated in the World Health Organization European Childhood Obesity Surveillance Initiative. Logistic multilevel models were used to assess associations of parent-reported screen time as well as sleep duration (exposure variables) with consumption frequencies of 16 food items (outcome variables). All models were adjusted for age, sex, outdoor play time, maximum educational level of parents and sleep duration or screen time, depending on the exposure under investigation.

RESULTS

One additional hour of screen time was associated with increased consumption frequencies of 'soft drinks containing sugar' (1.28 [1.19;1.39]; odds ratio and 99% confidence interval), 'diet/light soft drinks' (1.21 [1.14;1.29]), 'flavoured milk' (1.18 [1.08;1.28]), 'candy bars or chocolate' (1.31 [1.22;1.40]), 'biscuits, cakes, doughnuts or pies' (1.22 [1.14;1.30]), 'potato chips (crisps), corn chips, popcorn or peanuts' (1.32 [1.20;1.45]), 'pizza, French fries (chips), hamburgers'(1.30 [1.18;1.43]) and with a reduced consumption frequency of 'vegetables (excluding potatoes)' (0.89 [0.83;0.95]) and 'fresh fruits' (0.91 [0.86;0.97]). Conversely, one additional hour of sleep duration was found to be associated with increased consumption frequencies of 'fresh fruits' (1.11 [1.04;1.18]) and 'vegetables (excluding potatoes)' (1.14 [1.07;1.23]).

CONCLUSION

The results suggest a potential relation between high screen time exposure and increased consumption frequencies of foods high in fat, free sugar or salt whereas long sleep duration may favourably be related to children's food choices. Both screen time and sleep duration are modifiable behaviours that may be tackled in childhood obesity prevention efforts.

Sleep characteristics, body mass index, and risk for hypertension in young adolescents

Inadequate sleep has been identified as a risk factor for a variety of health consequences. For example, short sleep durations and daytime sleepiness, an indicator of insufficient sleep and/or poor sleep quality, have been identified as risk factors for hypertension in the adult population. However, less evidence exists regarding whether these relationships hold within child and early adolescent samples and what factors mediate the relationship between sleep and risk for hypertension. Using data from the Study of Early Child Care and Youth Development, the present study examined body mass index (BMI) as a possible mediator for the effects of school-night sleep duration, weekend night sleep duration, and daytime sleepiness on risk for hypertension in a sample of sixth graders. The results demonstrated gender-specific patterns. Among boys, all three sleep characteristics predicted BMI and yielded significant indirect effects on risk for hypertension. Oppositely, only daytime sleepiness predicted BMI among girls and yielded a significant indirect effect on risk for hypertension. The findings provide clarification for the influence of sleep on the risk for hypertension during early adolescence and suggest a potential need for gender-specific designs in future research and application endeavors.

Sleep duration predicts cardiometabolic risk in obese adolescents

OBJECTIVE

To examine the independent contributions of objectively measured sleep duration and fragmentation on cardiometabolic risk accumulation in free-living obese adolescents.

STUDY DESIGN

Characteristics of metabolic syndrome (waist circumference, mean arterial pressure, fasting high-density lipoprotein cholesterol, triglycerides, glucose) were measured in obese adolescents and standardized residuals (z-scores) were summed (inverse high-density lipoprotein cholesterol) to create a continuous cardiometabolic risk score (cMetScore), adjusted for age, sex, and race. Sleep and physical activity were objectively measured in habitual, free-living conditions for 7 days (SenseWear Pro3, BodyMedia, Pittsburgh, Pennsylvania; n = 37; 54% female, ages 11-17 years). Associations between sleep duration and cMetScore were assessed via multiple linear regression.

RESULTS

Body mass index, total sleep time, and sleep session length were each correlated with cMetScore (P < .05 all). Total sleep time was inversely and independently associated with cMetScore (r = -0.535, P = .001) and was the best independent predictor of metabolic risk.

CONCLUSIONS

Sleep duration inversely predicts cardiometabolic risk in obese adolescents, even when we controlled for various measures of physical activity, anthropometry, and adiposity. Further research should investigate the biological mechanism of this relationship and the potential treatment effect of sleep intervention in decreasing cardiometabolic risk in this population.

Sleep duration and adiposity in older adolescents from Otago, New Zealand: relationships differ between boys and girls and are independent of food choice

Background

While relationships between sleep and BMI have been extensively studied in younger children the effect of sleep duration on adiposity in adolescents, who are undergoing rapid growth periods, is less well known. There is also a lack of consistent evidence on the role of sleep on other measures of adolescent body composition which may be more reflective of health than BMI in this age group. Previous research investigating whether these relationships differ between sexes is also inconsistent. Therefore the objective of this study was to investigate relationships between sleep duration and multiple body composition measures in older adolescents and to investigate if these relationships differ between boys and girls.

Methods

A web-based cross-sectional survey and anthropometric measurement of 685 adolescents (mean age 15.8 years) from 11 schools in Otago, New Zealand. Height and weight were measured by trained researchers and fat mass and fat-free mass were estimated using bio-impedance. Generalised estimating equations were used to examine associations between sleep duration and the following body composition measures: BMI, waist circumference (WC), waist-to-height ratio (WHtR), fat mass index (FMI), and fat-free mass index (FFMI). Analyses were adjusted for ethnicity, deprivation, the number of screens in the bedroom and fruit and vegetable consumption.

Results

When data from all participants were analysed together, no significant relationships were seen between sleep duration and any body composition measure but significant sex interactions were seen. An hour increase in average nightly sleep duration in boys only was associated with decreases of 1.2% for WC, 0.9% for WHtR, 4.5% for FMI and 1.4% for FFMI in multivariate models. Similar results were seen for weekday and weekend night sleep duration.

Conclusions

Sex specific factors may play a role in relationships between sleep and body composition in older adolescents. The results in boys were most pronounced for FMI, a measure of total adiposity, which suggests that insufficient sleep in adolescent boys may affect fat mass more than lean mass and that the use of measures such as BMI may result in an under-estimation of relationships.

School-based programs aimed at the prevention and treatment of obesity: evidence-based interventions for youth in Latin America

BACKGROUND

Rapidly rising childhood obesity rates constitute a public health priority in Latin America which makes it imperative to develop evidence-based strategies. Schools are a promising setting but to date it is unclear how many school-based obesity interventions have been documented in Latin America and what level of evidence can be gathered from such interventions.

METHODS

We performed a systematic review of papers published between 1965 and December 2010. Interventions were considered eligible if they had a school-based component, were done in Latin America, evaluated an obesity related outcome (body mass index [BMI], weight, %body fat, waist circumference, BMI z-score), and compared youth exposed vs not exposed.

RESULTS

Ten studies were identified as having a school-based component. Most interventions had a sample of normal and overweight children. The most successful interventions focused on prevention rather than treatment, had longer follow-ups, a multidisciplinary team, and fewer limitations in execution. Three prevention and 2 treatment interventions found sufficient improvements in obesity-related outcomes.

CONCLUSIONS

We found sufficient evidence to recommend school-based interventions to prevent obesity among youth in Latin America. Evidence-based interventions in the school setting should be promoted as an important component for integrated programs, policies, and monitoring frameworks designed to reverse the childhood obesity in the region.

Estimation of regression quantiles in complex surveys with data missing at random: An application to birthweight determinants

The estimation of population parameters using complex survey data requires careful statistical modelling to account for the design features. This is further complicated by unit and item nonresponse for which a number of methods have been developed in order to reduce estimation bias. In this paper, we address some issues that arise when the target of the inference (i.e. the analysis model or model of interest) is the conditional quantile of a continuous outcome. Survey design variables are duly included in the analysis and a bootstrap variance estimation approach is proposed. Missing data are multiply imputed by means of chained equations. In particular, imputation of continuous variables is based on their empirical distribution, conditional on all other variables in the analysis. This method preserves the distributional relationships in the data, including conditional skewness and kurtosis, and successfully handles bounded outcomes. Our motivating study concerns the analysis of birthweight determinants in a large UK-based cohort of children. A novel finding on the parental conflict theory is reported. R code implementing these procedures is provided.

Association between sleeping hours and siesta and the risk of obesity: the SUN Mediterranean Cohort

OBJECTIVES

Our aim was to investigate the association between sleeping hours at night and during the siesta and the incidence of obesity in a Mediterranean cohort.

METHODS

After a median of 6.5 years of follow-up, we included 10,532 or 9,470 participants without chronic disease or obesity at baseline for analyzing the association between the incidence of obesity and nocturnal sleep duration or having siesta. Sleeping hours and siesta were assessed at baseline. Weight was recorded at baseline and every 2 years during the follow-up. The outcome was the incidence of obesity during follow-up among participants with initial BMI <30 kg/m(2).

RESULTS

During follow-up we observed 446 new cases of obesity in the analysis of nocturnal sleep duration. Sleeping less than 5 h at night was associated with a higher risk of becoming obese compared to sleeping between 7 and <8 h (HR 1.94; 95% CI 1.19-3.18; p for quadratic trend = 0.06) after adjusting for potential confounders. During follow-up, we observed 396 incident cases of obesity in the analysis of siesta. Those who took a siesta for 30 min/day had a 33% lower risk of becoming obese (HR 0.67; 95% CI 0.46-0.96; p for quadratic trend = 0.13) compared to those who did not take siesta.

CONCLUSION

Our results suggest that short nocturnal sleep duration could be a modifiable risk factor for obesity. It is possible that this association may be stronger among men and subjects who experienced previous weight gain. Additionally, siesta might be a novel and independent protective factor for obesity; however, confirmatory studies are needed.

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.