Quantity versus quality of objectively measured sleep in relation to body mass index in children: cross-sectional and longitudinal analyses

The sleep problems in individuals with Rett syndrome and their caregivers

LAY ABSTRACT

Sleep problems are common and impactful among individuals with Rett syndrome (RTT) and their caregivers. We examined the sleep patterns of 29 RTT patients and their primary caregivers using various assessment tools. The study found that a majority of the patients experienced sleep disturbances, with younger patients showing more sleep difficulties. Caregivers also reported poor sleep quality. The findings emphasize the need to address sleep problems in RTT management, as improving sleep quality can positively impact the well-being of individuals with RTT and their caregivers.

Delayed bedtime on non-school days associates with higher weight and waist circumference in children: Cross-sectional and longitudinal analyses with Mendelian randomisation

Sleep duration has been linked with obesity in population-based studies. Less is known about bedtimes and, especially, if discrepancy between bedtimes on school and non-school days associate with adiposity in children. The associations of self-reported bedtimes with the body mass index z-score (BMIz) and waist-to-height ratio (WtHr) were examined among children with a mean (SD) age of 11.2 (0.85) years in cross-sectional (n = 10,245) and longitudinal (n = 5085) study settings. The causal relationship of whether BMIz contributes to bedtimes, was further examined in a subset of 1064 participants by exploiting Mendelian randomisation (MR). After adjusting for sleep duration and other confounders, every 0.5 h later bedtime on non-school nights and a delay in bedtime in non-school nights compared with school nights associated with 0.048 (95% CI 0.027; 0.069) and 0.08 (95% CI 0.056; 0.105) higher BMIz as well as 0.001 (95% CI 0; 0.002) and 0.004 (95% CI 0.003; 0.005) with higher WtHr, respectively. Moreover, every 0.5-h delay in bedtime in non-school nights compared with school nights associated with 0.001 (95% CI 0; 0.002) greater increase in WtHr in the 2.5 years follow-up. Thus, a 2-h delay in bedtime at the age of 11 years corresponds with a 0.6 cm increase in waist circumference. The MR analysis did not indicate an opposite causal relationship: higher BMIz was not causing delayed bedtimes. Later bedtime on non-school days and discrepancy in bedtimes associated with increased BMIz and WtHr, while longitudinally these predicted higher WtHr, independently of sleep duration. Promoting early bedtimes, especially on weekends, should be considered in obesity prevention among school-aged children.

[Relationship between diet, nutritional aspects and sleep quality in a pediatric population]

Introduction

The relationship between diet and sleep has been studied in adults. However, there is little evidence in the pediatric population. The objective of this review was to analyze in a narrative way the relationship between diet, some nutritional aspects and sleep quality in population under 14 years. A quick review was performed in MEDLINE (PubMed) and Cochrane with a search strategy combining MeSH terms and keywords. Studies were selected to estimate diet and evaluate nutritional status and sleep in children using different tools. The risk of bias from the 14 selected studies was determined with validated tools (AMSTAR 2, Newcastle Ottawa scale [NOS] and Risk of Bias [Rob2]). Adherence to some dietary patterns such as the Mediterranean, high consumption of fruits and vegetables, tryptophan intake or substitution of saturated fatty acids by unsaturated fats were associated with better sleep quality. The consumption of ultra-processed products, the "unhealthy fast food" or the high intake of simple sugars hinder an adequate rest. On the other hand, an association between a high body mass index and lack of sleep was observed in young people under 14. In conclusion, the collected studies showed a significant association between some dietary patterns, food groups and nutrients with sleep quality. "Unhealthy" dietary factors were associated with poorer sleep quality. However, healthier and recommended habits and diets were associated with improved sleep hygiene. On the other hand, the lack of hours of rest in the youth population increases height, weight and BMI. Further research is needed in this direction.

Effects of Early Wake-Up Time on Obesity in Adolescents

Background: Although numerous studies have reported that obesity in adolescents is related to shorter sleep duration, few studies have reported the effect of sleep timing, particularly early wake-up time, on obesity. Objectives: To investigate the association between wake-up time and adolescent obesity. Methods: Using the Korean National Health and Nutrition Examination Survey VII data, 1301 middle school and high school students were selected and grouped according to BMI. Sleep timing and lifestyle factors were evaluated using self-reported questionnaires. Results: The mean bedtime and wake-up time were 00:09 am and 07:06 am, respectively. Despite similar bedtimes, the group with overweight/obesity woke up earlier than the group with underweight/normal weight. The BMI z-score and the overweight/obesity relative risk decreased as the wake-up time was delayed, even after adjustment for covariates. Participants who woke up before 06:50 am had a 1.82-fold higher risk of having overweight/obesity than those who woke up after 07:30 am. Participants who woke up late tended to sleep longer than those who woke up early. Conclusions: Waking up early is significantly associated with an increased BMI z-score in adolescents and may be a risk factor for overweight/obesity.

Association between sleep duration and latency, nocturnal awakenings, and body mass index among infants

OBJECTIVE

To investigate the association between sleep duration, nocturnal awakenings, and sleep latency with body mass index (BMI) at six and 12 months of age.

METHODS

179 children from a birth cohort were enrolled. At six and 12 months of age, anthropometric data were obtained using standardized techniques and infants' mothers answered the Brief Infant Sleep Questionnaire for sleep data. The association of BMI with the independent variables (sleep duration, latency, and nocturnal awakenings) was assessed by linear regression models. Analyses were adjusted for potential confounders and a p-value<0.05 was adopted to define statistical significance.

RESULTS

For each additional hour of sleep duration, BMI was reduced by 0.15 kg/m² (95% confidence interval [CI] -0.28; -0.01; p=0.03) and each additional minute of sleep latency increased BMI by 0.01 kg/m² (95%CI -0.00; 0.03; p=0.02). These associations were independent of gestational age, child sex, birth weight, duration of exclusive breastfeeding, smoking during pregnancy, and mother's BMI, education, and marital status. Nocturnal awakenings showed no association with the outcome.

CONCLUSIONS

Our findings suggest that sleep duration and sleep latency time are associated with BMI in the first year of life. Insights into the influence of sleep early in life on weight status may be helpful to complement future nutritional recommendations and prevent and treat obesity.

Obesogenic sleep patterns among Chinese preschool children: A latent profile and transition analysis of the association sleep patterns and obesity risk

OBJECTIVE

This paper utilized a person-centered approach to examine whether sleep patterns on school and free days are associated with obesity risk in preschool children aged 3-6 years.

METHODS

The cross-sectional analysis included 204 children from the Wuhan Healthy Start Project with valid sleep data in at least four consecutive days gathered via Actigraph GT3X+. Based on three domains of sleep duration, sleep onset, and sleep offset, we used latent profile analysis to identify distinct sleep patterns on school and free days separately. Additionally, we conducted latent transition analysis to explore the probabilities of sleep patterns transitions between school and free days. The multivariate logistic regression model investigated the associations of sleep patterns with overweight/obesity (OWO) (BMI ≥ age- and sex-specific 85th percentile) and abdominal obesity (AO) (WC ≥ age- and sex-specific 75th percentile).

RESULTS

Two sleep patterns were identified for school days: "EL-sc" (early-to-sleep/longer-duration) (n = 119; 58.3%) and "LS-sc" (late-to-sleep/shorter-duration) (n = 85; 41.7%). Similarly, "LES-fr" (late-to-sleep/early-to-wake/shorter-duration) (n = 118; 57.8%) and "ELL-fr" (early-to-sleep/late-to-wake/longer-duration) (n = 86; 42.2%) patterns were identified for free days. LTA categorized the participants into four distinct transition groups, i.e., "EL-sc→ELL-fr" (32.9%), "EL-sc→LES-fr" (24.0%), "LS-sc→LES-fr" (33.8%), and "LS-sc→ELL-fr" (9.3%). Compared with the "ELsc→ELL-fr", the "LS-sc→LES-fr" had a higher risk of OWO (AOR 4.76; 95% CI: 1.39-20.33) and AO (AOR, 2.78; 95% CI, 1.21-6.62), respectively. Neither "EL-sc→LES-fr" (AOR, 1.11; 95% CI, 0.14-6.67) nor "LS-sc→ELL-fr" (AOR, 0.74; 95% CI, 0.03-6.14) was significantly associated with OWO. Likewise, no significant association was observed for "EL-sc→LES-fr" (AOR, 0.96; 95% CI, 0.35-2.62) and "LS-sc→ELL-fr" (AOR, 0.56; 95% CI, 0.11-2.18) with AO.

CONCLUSIONS

"LS-sc→LES-fr" pattern is significantly associated with an increased risk of general and abdominal obesity, indicating its obesogenic nature. Furthermore, although not statistically associated with obesity outcomes, "LS-sc→ELL-fr" and "EL-sc→LES-fr" patterns exhibit a semi-obesogenic characteristic. In addition, we identified a concerning trend that preschool children are at risk of transitioning to and persisting in sleep patterns characterized by delayed and shorter sleep. These findings underscore the importance of implementing interventions and strategies to address sleep patterns as a crucial step to minimize the risk of obesity.

The gendered health consequences of persistent exposure to short sleep duration during adolescence

INTRODUCTION

Despite evidence that sleep duration is associated with adolescent health, there remain several gaps in the literature. Little is known about: (1) the extent to which persistent exposure to short sleep duration is associated with adolescent health and (2) whether this association varies by gender.

METHODS

Using six waves of longitudinal data from the 2011-2016 Korean Children and Youth Panel Survey (N = 6147), this study examined whether persistent exposure to short sleep duration is related to two adolescent health outcomes (overweight status and self-rated health). Fixed effects models were estimated to account for individual-level heterogeneity.

RESULTS

Short sleep duration was associated with being overweight and self-rated health in different ways for boys and girls. Gender-stratified analysis suggests that, for girls, the risk of being overweight increased for 5 years in a row as short sleep duration persisted. Prolonged short sleep duration also resulted in a continued decline in girls' self-rated health. For boys, persistent exposure to short sleep duration predicted a lower likelihood of being overweight up to the fourth year, but then began to recover. No association between persistent exposure to short sleep duration and self-rated health was observed for boys.

CONCLUSION

Persistent exposure to short sleep duration was found to be more harmful to the health of girls than boys. Promoting longer sleep duration during adolescence may be an effective intervention to improve adolescent health, especially for girls.

The relationship between sleep duration and health among Pacific adolescents within New Zealand: Findings from the Pacific Islands families study

OBJECTIVE

Sleep insufficiency is bi-directionally associated with adverse behavioural, physical and mental health outcomes in paediatric populations. However, little is known about the degree of sleep insufficiency and its effect on Pacific adolescents' wellbeing.

METHODS

A cross-sectional study of 14-year old Pacific adolescents nested within a longitudinal birth cohort was conducted. Self-reported sleep duration was related to sentinel physical, mental, and risk taking behaviour measures in crude and adjusted logistic regression models. Complete case and multiple imputed analyses were conducted.

RESULTS

916 Pacific adolescents were eligible, with a mean age of 14.2 years. Valid sleep data were available from 828 (90.4%) participants, with only 220 (26.6%) meeting the recommended amount of sleep. Insufficient sleep duration was associated with significantly higher rates of depressive symptoms and risk taking behaviours. In multiple imputed analyses, increased body mass index was also significantly related.

CONCLUSIONS

Sleep insufficiency is ubiquitous among Pacific adolescents and associated with negative impacts on their health and wellbeing.

IMPLICATIONS FOR PUBLIC HEALTH

Insufficient sleep duration is amenable to change. Bespoke, culturally responsive public health strategies that draw attention to the importance of positive sleep practices are needed. Particularly, among adolescents who are at risk of experiencing the greatest burden of insufficient sleep.

Characteristic Sleep Patterns and Associated Obesity in Adolescents

Poor sleep adversely affects health and may cause obesity. Poor sleep includes short sleep duration, low quality of sleep, and sleep discrepancy. Although most studies have focused on the association between sleep duration and obesity, poor sleep is a significant risk factor for obesity. Adolescents have characteristic sleep patterns which correspond to poor sleep. Adolescents sleep late due to various biological and psychosocial factors; also, they wake up early to be on time for school. This causes them to sleep less. To make up for this sleep debt, adolescents sleep more on non-school days, which causes sleep discrepancies. Therefore, since adolescents have characteristic sleep patterns, an in-depth investigation is needed to identify whether poor sleep is a risk for obesity. This article presents an overview of the characteristic sleep patterns of adolescents, and reviews studies on the association of each sleep pattern with obesity.

Sleep duration, physical activity, and caloric intake are related to weight status in Mexican American children: a longitudinal analysis

BACKGROUND

Obesity is a serious issue, spanning all ages, and, in the U.S., disproportionately affects Latinos and African Americans. Understanding sleep, physical activity and dietary behaviors that may predict childhood obesity can help identify behavioral intervention targets.

METHODS

Data were drawn from a U.S. cohort study of 323 Mexican American 8-10-year-old children and their mothers, who participated in a longitudinal study over a 2-year period. Measures were collected at baseline (BL; child mean age = 8.87, SD = 0.83), year 1 (FU1) and year 2 (FU2). Mothers reported on household income and acculturation at BL. Child height and weight were collected and BMI z-scores (BMIz) were calculated for weight status at BL, FU1, and FU2. Accelerometer-estimated sleep duration (hours) and moderate-to-vigorous physical activity (MVPA; minutes) were collected across 3 days at BL, FU1, and FU2. Two 24-h dietary recalls were performed at each time point; from these, average energy intake (EI, kcals/day) was estimated. Cross-lagged panel analysis was used to examine behavioral predictors on BMIz at each time point and across time.

RESULTS

At BL and FU1, longer sleep duration (β = - 0.22, p < 0.001; β = - 0.17, p < 0.05, respectively) and greater MVPA (β = - 0.13, p < 0.05; β = - 0.20, p < 0.01, respectively) were concurrently related to lower BMIz. At FU2, longer sleep duration (β = - 0.18, p < 0.01) was concurrently related to lower BMIz, whereas greater EI (β = 0.16, p < 0.01) was related to higher BMIz. Longer sleep duration at BL predicted lower BMIz at FU1 (β = - 0.05, p < 0.01).

CONCLUSIONS

Longer sleep duration was concurrently related to lower weight status at each time point from ages 8-10 to 10-12. Higher MVPA was concurrently related to lower weight status in earlier childhood (ages 8-10 and 9-11) and higher EI was concurrently related to higher weight status toward the end of childhood (ages 10-12 years). Furthermore, longer sleep in earlier childhood was protective of children's lower weight status 1 year later. These findings suggest that sleep duration plays a consistent and protective role against childhood obesity; in addition, MVPA and healthy EI remain important independent factors for obtaining a healthy weight.

Cross-sectional associations between objectively measured sleep characteristics and body mass index in European children and adolescents

BACKGROUND

Short sleep duration has been found to be associated with a higher risk for overweight and obesity. However, previous studies have mainly relied on subjective measures of sleep duration and other sleep characteristics (eg quality, timing) have often been neglected. Therefore, we aimed to investigate associations between several, mainly objectively measured sleep characteristics and body mass index (BMI). Further, we aimed to identify distinct sleep subtypes based on these sleep characteristics and to study their association with BMI.

METHODS

Children aged 9-16 years participating in the European I.Family study (N = 559, 51.2% girls, 32.9% overweight/obese) wore an accelerometer for one week on their wrist and recorded their daily wake-up and lights-off times in a sleep diary. Information on sleep duration, sleep efficiency and sleep latency was derived. To identify sleep subtypes, we conducted a latent class analysis using all five sleep variables. Associations between single sleep variables, sleep subtype and age- and sex-specific BMI z-score were investigated using linear mixed-effects regression models to accommodate clustering among siblings.

RESULTS

No statistically significant associations were observed between the single sleep variables (sleep duration, sleep efficiency, sleep latency, wake-up and lights-off times) and BMI z-score. Four sleep subtypes were identified and children were assigned to one of the groups based on their highest probability for latent group membership: "early birds" (17.5% of the sample), "short sleep duration" (14.7%), "optimal sleep" (47.6%) and "poor sleep quality" (20.2%). Sleep subtype was not associated with BMI z-score.

CONCLUSIONS

Using objective sleep data, we did not find convincing evidence for associations between the sleep variables under investigation and BMI.