The association of urbanicity with infant sleep duration

Associations of Prenatal Per- and Polyfluoroalkyl Substance (PFAS) Exposures with Offspring Adiposity and Body Composition at 16-20 Years of Age: Project Viva

BACKGROUND

Findings on the associations between prenatal PFAS exposures and offspring adiposity are inconsistent. Whether such associations may extend to adolescence is especially understudied.

OBJECTIVES

We investigated associations of prenatal PFAS exposures with offspring adiposity and body composition at 16-20 years of age.

METHODS

We studied 545 mother-child pairs in the prospective prebirth cohort Project Viva (Boston, Massachusetts). We measured six PFAS (PFOA, PFOS, PFNA, PFHxS, EtFOSAA, and MeFOSAA) in maternal early pregnancy (median age = 9.6 wk , range: 5.7-19.6 wk) plasma samples. At the late adolescence visit (median age = 17.4 y, range: 15.9-20.0 y), we obtained anthropometric measures and assessed body composition using bioelectrical impedance analysis and dual-energy X-ray absorptiometry. We examined associations of individual PFAS with obesity [i.e., age- and sex-specific body mass index (BMI) ≥ 95 th percentile] and adiposity and body composition using multivariable Poisson and linear regression models, respectively. We assessed PFAS mixture effects using Bayesian kernel machine regression (BKMR) and quantile g-computation. We used fractional-polynomial models to assess BMI trajectories (at 3-20 years of age) by prenatal PFAS levels.

RESULTS

Thirteen percent (n = 73 ) of the children had obesity in late adolescence. After multivariable adjustment, higher prenatal PFAS concentrations were associated with higher obesity risk [e.g., 1.59 (95% CI: 1.19, 2.12), 1.24 (95% CI: 0.98, 1.57), and 1.49 (95% CI: 1.11, 1.99) times the obesity risk per doubling of PFOS, PFOA, and PFNA, respectively]. BKMR showed an interaction between PFOA and PFOS, where the positive association between PFOS and obesity was stronger when PFOA levels were lower. Each quartile increment of the PFAS mixture was associated with 1.52 (95% CI: 1.03, 2.25) times the obesity risk and 0.52 (95% CI: - 0.02 , 1.06) kg / m 2 higher BMI. Children with higher prenatal PFOS, EtFOSAA, and MeFOSAA concentrations had higher rates of BMI increase starting from 9-11 years of age.

DISCUSSION

Prenatal PFAS exposures may have obesogenic effects into late adolescence. https://doi.org/10.1289/EHP12597.

Feasibility and acceptability of mobile methods to assess home and neighborhood environments related to adolescent sleep

OBJECTIVE

A growing evidence base suggests home and neighborhood environmental exposures may influence adolescent sleep, but few studies have assessed these relationships using methods that account for time-varying, location-specific exposures, or multiple neighborhood contexts. This study aimed to assess the feasibility and acceptability of using smartphone global positioning system (GPS) tracking and ecological momentary assessment (EMA) to assess time-varying home and neighborhood environmental exposures hypothesized to be associated with adolescent sleep.

METHODS

Adolescents aged 15-17 years in Philadelphia completed 7 days of continuous smartphone GPS tracking, which was used to identify daily levels of exposure to geocoded neighborhood factors (eg, crime, green space). Four daily EMA surveys assessed home sleep environment (eg, noise, light), stress, health behaviors, and neighborhood perceptions. Feasibility and acceptability of GPS tracking and EMA were assessed, and distributions of daily environmental exposures were examined.

RESULTS

Among 25 teens (mean age 16, 56% male), there was a high level of GPS location data captured (median daily follow-up: 24 hours). Seventy-eight percent of EMA surveys were completed overall. Most participants (96%) reported no privacy concerns related to GPS tracking and minimal burden from EMA surveys. Exposures differed between participants' home neighborhoods and locations visited outside the home neighborhood (eg, higher crime away from home). Sleep environment disruptions were present on 29% of nights (most common: uncomfortable temperature) and were reported by 52% of adolescents.

CONCLUSIONS

Results demonstrate the feasibility and acceptability of mobile methods for assessing time-varying home and neighborhood exposures relevant to adolescent sleep for up to 1 week.

Co-Rooming Accounts for Socioeconomic Disparities in Infant Sleep Quality among Families Living in Urban Environments

Poor infant sleep quality is associated with negative maternal and infant health outcomes. This study measures socioeconomic disparities in infant sleep quality, and assesses whether child sleep location and maternal stress mediate associations between socioeconomic status (SES) and infant sleep quality. The study includes 86 socioeconomically diverse, mother-infant dyads living in an urban area with infants aged 6–12 months. Mothers reported socioeconomic demographics, infant sleep quality (Brief Infant Sleep Questionnaire) and maternal subjective stress (Perceived Stress Scale). Maternal objective stress was measured via hair cortisol concentration (HCC). The associations among SES, infant sleep quality, infant co-rooming, and maternal stress were assessed. Infants from families with lower income-to-needs (ITN) ratios had poorer infant sleep quality. The association between familial ITN and infant sleep quality was mediated by whether the child co-rooms with parents. Maternal perceived stress was independently associated with infant sleep quality, but HCC was not associated with infant sleep quality.

Association of sleep quality with temperament among one-month-old infants in The Japan Environment and Children’s Study

This study aimed to examine the association between infant sleep quality and temperament in one-month-old infants using a large cohort study data. We used data from the Japan Environment and Children’s Study, a cohort study which follows around 100,000 women from pregnancy until their children’s development. The mothers were asked about their infants’ sleep and temperament using a structured questionnaire. Frequent crying (adjusted odds ratio [AOR]: 1.05, 95% confidence interval [CI]: 1.00–1.10) and intense crying (AOR: 1.19, 95% CI: 1.13–1.25) were positively associated with longer sleep periods during the day than at night. Female infants with longer daytime sleep periods than that at nighttime were more likely to cry frequently (AOR: 1.11, 95% CI: 1.04–1.20). Parous women with infants who had frequent night awakening believed their infants cried more intensely (AOR: 1.17, 95% CI: 1.03–1.31). The study demonstrated a specific association between sleep quality and temperament in one-month-old infants. Based on the results of this study, further sleep intervention studies are required to improve infant temperament.

Early-Life Exposure to Green Space and Mid-Childhood Cognition in the Project Viva Cohort, Massachusetts

The association between early-life greenness and child cognition is not well understood. Using prospective data from Project Viva (n = 857) from 1999-2010, we examined associations of early-life greenness exposure with mid-childhood cognition. We estimated residential greenness at birth, early childhood (median age 3.1 years), and mid-childhood (7.8 years) using 30-m resolution Landsat satellite imagery (normalized difference vegetation index). In early childhood and mid-childhood, we administered standardized assessments of verbal and nonverbal intelligence, visual-motor abilities, and visual memory. We used natural splines to examine associations of early life-course greenness with mid-childhood cognition, adjusting for age, sex, race, income, neighborhood socioeconomic status, maternal intelligence, and parental education. At lower levels of greenness (greenness <0.6), greenness exposure at early childhood was associated with a 0.48% increase in nonverbal intelligence and 2.64% increase in visual memory in mid-childhood. The association between early-childhood greenness and mid-childhood visual memory was observed after further adjusting for early childhood cognition and across different methodologies, while the association with nonverbal intelligence was not. No other associations between early life-course greenness and mid-childhood cognition were found. Early childhood greenness was nonlinearly associated with higher mid-childhood visual memory. Our findings highlight the importance of nonlinear associations between greenness and cognition.

Early life exposure to greenness and executive function and behavior: An application of inverse probability weighting of marginal structural models

Increasingly, studies suggest benefits of natural environments or greenness on children's health. However, little is known about cumulative exposure or windows of susceptibility to greenness exposure. Using inverse probability weighting of marginal structural models (IPW/MSM), we estimated effects of greenness exposure from birth through adolescence on executive function and behavior. We analyzed data of 908 children from Project Viva enrolled at birth in 1999-2002 and followed up until early adolescence. In mid-childhood (median 7.7 years) and early adolescence (13.1 years), executive function and behavior were assessed using the Behavior Rating Inventory of Executive Function and the Strengths and Difficulties Questionnaire (SDQ). Greenness was measured at birth, early childhood, mid-childhood, and early adolescence, using the Normalized Difference Vegetation Index. We used inverse probability weighting of marginal structural models to estimate effects of interventions that ensure maximum greenness exposure versus minimum through all intervals; and that ensure maximum greenness only in early childhood (vs. minimum through all intervals). Results of the effects of "maximum (vs. minimum) greenness at all timepoints" did not suggest associations with mid-childhood outcomes. Estimates of "maximum greenness only in early childhood (vs. minimum)" suggested a beneficial association with mid-childhood SDQ (-3.21, 99 %CI: -6.71,0.29 mother-rated; -4.02, 99 %CI: -7.87,-0.17 teacher-rated). No associations were observed with early adolescent outcomes. Our results for "persistent" maximum greenness exposure on behavior, were not conclusive with confidence intervals containing the null. The results for maximum greenness "only in early childhood" may shed light on sensitive periods of greenness exposure for behavior regulation.

Correlates of Objectively Measured Sleep and Physical Activity Among Latinx 3-To-5-Year Old Children

PURPOSE

Latinx children have the highest prevalence of obesity in the US. Physical activity (PA) and sleep are important risk factors for this health disparity, yet limited evidence exists examining objectively measured data among this population. We aim to identify correlates of sleep and PA, as well as the association between sleep and PA, among a sample of Latinx children.

DESIGN AND METHODS

A cross-sectional study was conducted with thirty Latinx 3-to-5-year old children who wore GT3X+ triaxial accelerometers for five consecutive days, from which we examined sleep and PA constructs. Linear regression and ANOVA were used to examine study constructs.

RESULTS

Sedentary behavior, light PA, and MVPA (moderate-to-vigorous PA) were 51.7, 5.6, and 2.6 min/h respectively. Total sleep duration averaged 9.6 h, sleep efficiency averaged 80.0%, and sleep variability averaged 1.30 h/night. Higher household income was associated with sleep variability (F = 7.240, p = .012) and lower sedentary behavior (F = 5.481, p = .027), and higher sleepiness was associated with lower MVPA (β = -0.503, p = .005) and higher child BMI (β = 0.531, p = .033). MVPA was associated with higher sleep efficiency (β = 0.441, p = .016).

CONCLUSIONS

Household income emerged as a correlate of sleep variability and sedentary behavior in our study. In addition, we found that MVPA levels were associated with sleep efficiency.

PRACTICE IMPLICATIONS

Our results signal an impetus for further research (particularly with larger, multi-site study designs) examining study constructs among Latinx children.

Measurement of screen time among young children aged 0-6 years: A systematic review

The impact of screen-based devices on children's health and development cannot be properly understood without valid and reliable tools that measure screen time within the evolving digital landscape. This review aimed to summarize characteristics of measurement tools used to assess screen time in young children; evaluate reporting of psychometric properties; and examine time trends related to measurement and reporting of screen time. A systematic review of articles published in English across three databases from January 2009 to April 2020 was undertaken using PROSPERO protocol (registration: CRD42019132599) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included articles measured screen time as outcome, exposure, or confounder in children 0-6 years. The search identified 35,868 records, 1035 full-text articles were screened for eligibility, and 622 met inclusion criteria. Most measures (60%) consisted of one to three items and assessed duration of screen time on a usual day. Few measures assessed content (11%) or coviewing (7%). Only 40% of articles provided a citation for the measure, and only 69 (11%) reported psychometric properties-reliability n = 58, validity n = 19, reliability and validity n = 8. Between 2009 and 2019, the number of published articles increased from 28 to 71. From 2015, there was a notable increase in the proportion of articles published each year that assessed exposure to mobile devices in addition to television. The increasing number of published articles reflects increasing interest in screen time exposure among young children. Measures of screen time have generally evolved to reflect children's contemporary digital landscape; however, the psychometric properties of measurement tools are rarely reported. There is a need for improved measures and reporting to capture the complexity of children's screen time exposures.

Neighborhood Socio-Economic Factors and Associations with Infant Sleep Health

Background: Sleep health is important for development and improves overall health. There are large socioeconomic gradients in sleep health, from childhood through adulthood. Recent findings suggest that children from neighborhoods with poorer socioeconomic conditions have more sleep problems. The current study aimed to investigate the associations between neighborhood factors and infant sleep health.

PARTICIPANTS AND METHODS

Secondary data analysis using Multilevel Modeling (MLM) was conducted for a subsample of 2445 women from the All our Families longitudinal cohort study, for whom early pregnancy neighborhood data could be geocoded. The Vancouver Area Neighborhood Deprivation Index (VANDIX) was calculated using census data to assess neighborhood SES. Neighborhood disorder was measured using community crime reports from police services. Mothers rated the perceived safety of their neighborhood and reported on their infants' nighttime sleep consolidation, awakenings, and onset latency at 12 months postpartum.

RESULTS

MLM indicated that neighborhood disorder and maternal perceptions of unsafety predicted less consolidated sleep after accounting for individual and family-level factors including maternal ethnicity, household income, breastfeeding duration, and co-sleeping. Neighborhood deprivation was indirectly related to less consolidated sleep among 12-month-old infants through more reports of disorder and maternal perceptions of less safety.

CONCLUSIONS

Consistent with the socio-ecological model of sleep, neighborhood-level, family, and individual factors influence infant sleep health. Policy efforts to increase neighborhood safety and public health initiatives to increase awareness of the importance of sleep could help improve infant sleep health.

Associations of the residential built environment with adolescent sleep outcomes

STUDY OBJECTIVES

Over 75% of US high school students obtain insufficient sleep, placing them at risk for adverse health outcomes. Identification of modifiable determinants of adolescent sleep is needed to inform prevention strategies, yet little is known about the influence of the built environment on adolescent sleep.

METHODS

In this prospective study, actigraphy was used to assess sleep outcomes among 110 adolescents for 14 days each in eighth and ninth grades: duration (hours/night), onset and offset, and sleeping ≥8 hours. Home addresses were linked to built environment exposures: sound levels, tree canopy cover, street density, intersection density, population density, and housing density. Mixed-effects regression estimated associations of built environment measures with sleep outcomes, adjusting for sex, race, parent education, household income, household size, grade, weeknight status, and neighborhood poverty.

RESULTS

A 1-standard deviation (SD) increase in neighborhood sound was associated with 16 minutes later sleep onset (β = 0.28; 95% confidence interval (CI): 0.06, 0.49) and 25% lower odds of sleeping for ≥8 hours (odds ratio (OR) = 0.75, 95% CI: 0.59, 0.96). A 1-SD increase in neighborhood tree canopy was associated with 18 minutes earlier sleep onset (β = -0.31, 95% CI: -0.49, -0.13) and 10 minutes earlier sleep offset (β= -0.17, 95% CI: -0.28, -0.05). No associations were observed for density-based exposures.

CONCLUSIONS

Higher neighborhood sound level was associated with lower odds of sufficient sleep, while higher tree canopy cover was associated with more favorable sleep timing. Neighborhood sound levels and tree canopy cover are potential targets for policies and interventions to support healthier sleep among adolescents.

Neighborhood environments and sleep among children and adolescents: A systematic review

Understanding salient environmental determinants of pediatric sleep is essential for informing interventions and public health initiatives. Emerging evidence suggests that the neighborhood environment can impact pediatric sleep, but this evidence has not yet been systematically reviewed. We conducted a systematic review of the scientific literature on associations between neighborhood environments and sleep in young children (0-5 y), school-aged children (6-12 y) and adolescents (13-18 y). We reviewed 85 articles published between 2003 and 2020. The most commonly examined neighborhood exposure was low socioeconomic status (40 studies), which was associated with sleep outcomes in 58% of studies (primarily shorter sleep duration, later sleep timing, or obstructive sleep apnea). Evidence was stronger for neighborhood safety/crime/violence (21 studies), with 86% of studies reporting associations with sleep outcomes (primarily self- or caregiver-reported sleep problems). Fewer studies examined associations of neighborhood physical environment exposures, including noise (15 studies), the built environment (seven studies), and air pollution (six studies). Limitations of the current body of evidence include 1) limited examination of neighborhood exposures other than socioeconomic status or safety, 2) use of primarily cross-sectional observational study designs, 3) lack of objective sleep outcome assessment, and 4) limits of current exposure assessment methods.

Correlates of Sleep Duration in Early Childhood: A Systematic Review

OBJECTIVE

This systematic review aimed to summarize correlates of sleep duration in children under 5 years of age.

METHODS

Six electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, SPORTDiscus, and Scopus) were searched from inception to May 2019. Observational studies and intervention studies reporting cross-sectional results from baseline data were considered. Data were extracted using a predesigned form and potential correlates were categorized following a sociological framework.

RESULTS

One-hundred and sixteen studies, representing 329,166 children, met the inclusion criteria, with a high risk of bias in 62 included studies. A total of 83 correlates of sleep duration were identified. Among the associations studied four or more times, correlates of nap duration were child's age and nighttime sleep onset/bedtime; correlates of nighttime sleep duration were household income, parent marital status, parental adiposity level, nighttime sleep duration at younger age, nighttime sleep onset/bedtime, nighttime sleep wakeup time, and frequency of current bedtime routine; correlate of total sleep duration was screen time.

CONCLUSIONS

Young children from low-income households, single families, or having overweight parents may be at risk for short sleep duration. Promoting healthy sleep duration from an early age appears essential. Effective practices may include encouraging an earlier bedtime, limiting screen time, and establishing a regular bedtime routine. The absence of consistent evidence in the psychological, cognitive, and emotional domain as well as the physical environmental domain warrants further research.

Socioeconomic disadvantage and sleep in early childhood: Real-world data from a mobile health application

OBJECTIVES

To examine whether increased socioeconomic disadvantage, indexed using a measure of community distress, was associated with variation in caregiver-reported early childhood sleep patterns and problems in a large US sample using a mobile health application (app).

DESIGN

Cross-sectional.

SETTING

Data were collected using the free, publicly available Johnson's Bedtime© baby sleep app.

PARTICIPANTS

A total of 14,980 caregivers (85.1% mothers) of children ages 6-35.9 months (M = 13.88 months; 52.6% boys) participated in this study.

MEASURES

Caregivers reported on child sleep using the Brief Infant Sleep Questionnaire-Revised. Socioeconomic disadvantage was indexed by zip code using the Distressed Communities Index (DCI), which combines seven US census indicators of socioeconomic disadvantage. DCI scores range from prosperous (lowest quintile) to distressed (highest quintile).

RESULTS

Socioeconomic disadvantage was significantly associated with later bedtimes, longer sleep onset latency, and shorter nighttime and 24-hour (total) sleep duration, with children living in distressed communities showing the poorest sleep. However, caregivers living in distressed communities reported a significantly lower prevalence of overall child sleep problems (43% vs 58% in prosperous communities), and more confidence in managing child sleep (42% vs 34% in prosperous communities).

CONCLUSIONS

Children living in the most distressed communities have the poorest reported sleep patterns and bedtime behaviors; however, their caregivers are less likely to report problematic child sleep. These findings highlight the need for community-level sleep health promotion interventions, as well as further investigation of caregiver perceptions about child sleep and sleep health promotion among families living in socioeconomically disadvantaged contexts.

Pediatric sleep health: It matters, and so does how we define it

In 2014, Buysse published a novel definition of sleep health, raising awareness for the importance of this construct for individuals, populations, clinical care, and research. However, the original definition focused on adults, with the recommendation that it should be adapted for children and adolescents. As children live within a complex and dynamic system, and may not always have control over their own sleep, this theoretical review will examine and apply Buysse's five dimensions of sleep health within the context of pediatrics. In addition, using examples from the pediatric sleep literature we introduce a modified definition that takes into consideration the influence of the socio-ecological system within which children live, and the sleep-related behaviors that are critical in supporting or hindering sleep health. Finally, we discuss how the proposed theoretical framework, Peds B-SATED, can be applied to clinical practice, research, and training in the field of pediatric sleep.

Effects of Coparenting Quality, Stress, and Sleep Parenting on Sleep and Obesity Among Latinx Children: A Path Analysis

INTRODUCTION

We sought to examine the associations among parent-level constructs, sleep-related parenting practices, and child sleep in Latinx families.

METHOD

A quantitative study was conducted with 101 Latinx parents of children aged 2-5 years. Key variables that were examined included parental stress, coparenting quality, bedtime routine consistency, parent-child sleep interactions, and child's sleep duration.

RESULTS

Path analysis results indicated that (1) parent stress had a direct effect on child sleep duration (p =.005) and was mediated by parent-child sleep interactions (p =.021); (2) coparenting quality had a direct effect on child sleep duration (p =.001) and was mediated by bedtime routine consistency (p =.010); and (3) bedtime routine consistency had an indirect effect on child body mass index percentile and was mediated by sleep duration (p =.049).

DISCUSSION

Coparenting quality and parental stress may be important constructs to consider when designing interventions to improve Latinx child sleep duration.

Exploring Parenting Contexts of Latinx 2-to-5-Year Old Children's Sleep: Qualitative Evidence Informing Intervention Development

PURPOSE

Poor sleep quality is associated with childhood obesity, and Latinx children have the highest prevalence of obesity in the United States. Parents are key agents to ensuring good sleep quality among children, but limited research has examined sleep parenting among Latinx working parents who may have added responsibilities.

DESIGN AND METHODS

Working Latinx parents of 2-to-5-year old children participated in in-depth interviews exploring parenting and familial contexts of child sleep. Main topics in the interview guide included sleep-related parenting practices, social support, cultural influences, and intervention service delivery and content preferences. Thematic analysis was used to analyze data.

RESULTS

Twenty parents completed the interview. The following themes emerged: Sleep parenting, sleep knowledge, impact of familial structures, family commitments, child temperament, and broader contextual factors on sleep, and intervention content and design ideas. Across participants, employment was reported to be a barrier to effective sleep parenting. Parents also reported engaging in practices that may interfere with sleep quality such as using screen time as a distraction and reducing naptime during the weekends to increase the amount of family time. Family-level factors such as co-parenting and spousal support were reported to facilitate sleep parenting. Participants also indicated the need for more sleep parenting knowledge and a preference for mobile platforms and social media to deliver information.

CONCLUSIONS

Results not only fill critical gaps in the literature, but also highlight the variability in parents' approaches to sleep parenting and an urgent need for intervention/programming efforts to target Latinx parent's sleep knowledge and parenting.

Maternal experiences of racial discrimination and offspring sleep in the first 2 years of life: Project Viva cohort, Massachusetts, USA (1999-2002)

OBJECTIVE

To examine the association of maternal lifetime experiences of racial discrimination with infant sleep duration over the first 2 years of life.

DESIGN

Prebirth cohort study.

SETTING

Massachusetts, USA (baseline: 1999-2002).

PARTICIPANTS

552 mother-infant dyads in Project Viva, for whom the mother self-identified as being a woman of color.

MEASUREMENTS

During pregnancy, mothers completed the Experiences of Discrimination survey that measured lifetime experiences of racial discrimination in eight domains. The main outcome was a weighted average of their infants' 24-hour sleep duration from 6 months to 2 years.

RESULTS

30% reported 0 domains of racial discrimination, 35% 1-2 domains, and 34% ≥3 domains. Any racial discrimination (≥1 vs. 0 domains) was higher among black (80%) versus Hispanic (58%) or Asian (53%) mothers and the United States versus foreign-born mothers (79% vs. 58%) and was associated with higher mean prepregnancy BMI (26.8 vs. 24.5 kg/m²). Children whose mothers reported ≥3 domains versus 0 domains had shorter sleep duration from 6 months to 2 years in unadjusted analysis (β -18.6 min/d; 95% CI -37.3, 0.0), which was attenuated after adjusting for maternal race/ethnicity and nativity (-13.6 min/d; -33.7, 6.5). We found stronger associations of racial discrimination with offspring sleep at 6 months (-49.3 min/d; -85.3, -13.2) than for sleep at 1 year (-13.5 min/d; -47.2, 20.3) or 2 years (4.2 min/d; -21.5, 29.9).

CONCLUSIONS

Maternal lifetime experiences of racial discrimination was associated with shorter offspring sleep duration at 6 months, but not with infant's sleep at 1 and 2 years of age.

Physical and Social Environment Relationship With Sleep Health and Disorders

Sleep health is a multidimensional construct that includes adequate duration, quality, and appropriately timed sleep that may be influenced by environmental factors. In this review, we focus on how an individual's living and sleeping environment, both the surrounding neighborhood physical and social features and the atmosphere around them, may impact their sleep health. We explore the associations of the physical environment (urban density, recreational facilities, green space, mixed land use, and healthy food stores), neighborhood deprivation (disadvantage and disorder), and the social environment (social cohesion, safety, and stigma) with sleep in both adult and pediatric populations. We investigate how physical and social environmental features may lead to alterations in the timing, duration, and quality of sleep and contribute to the most prevalent sleep disorders: insomnia, sleep apnea, and circadian rhythm disorders. We also review how ambient factors such as artificial light, environmental noise, and air pollution may contribute to sleep pathology. We have included key studies and recent emerging data regarding how the differential distribution of environmental factors that may affect sleep health may contribute to sleep health disparities.

Environmental Determinants of Insufficient Sleep and Sleep Disorders: Implications for Population Health

PURPOSE OF REVIEW

Sleep is important for overall health and well-being. Insufficient sleep and sleep disorders are highly prevalent among adults and children and therefore a public health burden, particularly because poor sleep is associated with adverse health outcomes. Emerging evidence has demonstrated that environmental factors at the household- and neighborhood-level can alter healthy sleep. This paper will (1) review recent literature on the environmental determinants of sleep among adults as well as children and adolescents; and (2) discuss the opportunities and challenges for advancing research on the environment and sleep.

RECENT FINDINGS

Epidemiologic research has shown that social features of environments, family, social cohesion, safety, noise, and neighborhood disorder can shape and/or impact sleep patterns; and physical features such as light, noise, traffic, pollution, and walkability can also influence sleep and is related to sleep disorders among adults and children. Prior research has mainly measured one aspect of the environment, relied on self-reported sleep, which does not correlate well with objective measures, and investigated cross-sectional associations. Although most studies are conducted among non-Hispanic white populations, there is growing evidence that indicates that minority populations are particularly vulnerable to the effects of the environment on insufficient sleep and sleep disorders.

SUMMARY

There is clear evidence that environmental factors are associated with insufficient sleep and sleep disorders. However, more research is warranted to evaluate how and which environmental factors contribute to sleep health. Interventions that target changes in the environment to promote healthy sleep should be developed, tested, and evaluated as a possible pathway for ameliorating sleep health disparities and subsequently health disparities.

Associations Between the Built Environment and Objective Measures of Sleep: The Multi-Ethnic Study of Atherosclerosis

Although dense neighborhood built environments support increased physical activity and lower obesity, these features may also disturb sleep. Therefore, we sought to understand the association between the built environment and objectively measured sleep. From 2010 to 2013, we analyzed data from examination 5 of the Multi-Ethnic Study of Atherosclerosis, a diverse population from 6 US cities. We fit multilevel models that assessed the association between the built environment (Street Smart Walk Score, social engagement destinations, street intersections, and population density) and sleep duration or efficiency from 1-week wrist actigraphy in 1,889 individuals. After adjustment for covariates, a 1-standard-deviation increase in Street Smart Walk Score was associated with 23% higher odds of short sleep duration (≤6 hours; odds ratio = 1.2, 95% confidence interval: 1.0, 1.4), as well as shorter average sleep duration (mean difference = -8.1 minutes, 95% confidence interval: -12.1, -4.2). Results were consistent across other built environment measures. Associations were attenuated after adjustment for survey-based measure of neighborhood noise. Dense neighborhood development may have multiple health consequence. In promoting denser neighborhoods to increase walkability, it is important to also implement strategies that reduce the adverse impacts of this development on sleep, such as noise reductions efforts.

Sleep Regulation, Physiology and Development, Sleep Duration and Patterns, and Sleep Hygiene in Infants, Toddlers, and Preschool-Age Children

Sleep problems are common, reported by a quarter of parents with children under the age of 5 years, and have been associated with poor behavior, worse school performance, and obesity, in addition to negative secondary effects on maternal and family well-being. Yet, it has been shown that pediatricians do not adequately address sleep in routine well-child visits, and underdiagnose sleep issues. Pediatricians receive little formal training in medical school or in residency regarding sleep medicine. An understanding of the physiology of sleep is critical to a pediatrician׳s ability to effectively and confidently counsel patients about sleep. The biological rhythm of sleep and waking is regulated through both circadian and homeostatic processes. Sleep also has an internal rhythmic organization, or sleep architecture, which includes sleep cycles of REM and NREM sleep. Arousal and sleep (REM and NREM) are active and complex neurophysiologic processes, involving both neural pathway activation and suppression. These physiologic processes change over the life course, especially in the first 5 years. Adequate sleep is often difficult to achieve, yet is considered very important to optimal daily function and behavior in children; thus, understanding optimal sleep duration and patterns is critical for pediatricians. There is little experimental evidence that guides sleep recommendations, rather normative data and expert recommendations. Effective counseling on child sleep must account for the child and parent factors (child temperament, parent-child interaction, and parental affect) and the environmental factors (cultural, geographic, and home environment, especially media exposure) that influence sleep. To promote health and to prevent and manage sleep problems, the American Academy of Pediatrics (AAP) recommends that parents start promoting good sleep hygiene, with a sleep-promoting environment and a bedtime routine in infancy, and throughout childhood. Thus, counseling families on sleep requires an understanding of sleep regulation, physiology, developmental patterns, optimal sleep duration recommendations, and the many factors that influence sleep and sleep hygiene.

Diet and nutrients in the modulation of infant sleep: A review of the literature

OBJECTIVES

The establishment of organized sleep patterns is an important developmental process during infancy. Little is known about the role of nutrition in sleep maturation. This review focuses on exploring the link between infant sleep and nutrition with the aim to provide an overview of existing literature on the impact of diet and specific nutrients on sleep modulation in infants.

METHODS

An exploratory literature search was performed on the topic in Medline, Scopus and Cochrane Library databases, with a focus on publications in English.

RESULTS

Both the type of nutrients consumed and the timing at which they were consumed, relative to sleeping time, have been reported to influence infant sleep. Some nutrients have been shown to naturally fluctuate in maternal breast milk with circadian rhythm, and nutrients such as tryptophan, nucleotides, essential fatty acids and Omega-3 long-chain fatty acids have been suggested to impact infant sleep.

DISCUSSION

In summary, little is known about the nutritional impact on infant sleep and sleep maturation, particularly with regard to specific nutrients. While nutrients like tryptophan and nucleotides seem to impact sleep at the level of brain activity, some fatty acids may affect sleep as a result of their role in supporting the maturity of the central nervous system. In our view, the existing literature indicates that the link between nutrition and infant sleep may be a promising concept to support this crucial phase of early development.

Association between greenness, urbanicity, and birth weight

BACKGROUND

More than half of the world's population lives in urban environments. Due to urban related factors (e.g. higher air pollution), urban residents may face higher risk of adverse health outcomes, while access to green space could benefit health.

PURPOSE

We explored associations between urban and green land-use and birth weight.

METHODS

Connecticut, U.S., birth certificate data (2000-2006) were acquired (n=239,811), and land-use data were obtained from the National Land Cover Database. We focused on three land-uses; urban space, urban open space, and green space (i.e. forest, shrub, herbaceous, and cultivated land). We estimated fractions of greenness and urbanicity within 250 m from residence. A linear mixed effects model was conducted for birth weight and a logistic mixed effects model for low birth weight (LBW) and small for gestational age (SGA).

RESULTS

An interquartile range (IQR) increment in the fraction of green space within 250 m of residence was associated with 3.2g (95% Confidence Interval [0.4, 6.0]) higher birth weight. Similarly, an IQR increase in green space was associated with 7.6% [2.6, 12.4] decreased risk of LBW. Exposure to urban space was negatively correlated with green space (Pearson correlation=-0.88), and it showed negative association with birth outcomes. Results were generally robust with different buffer sizes and controlling for fine particles (PM2.5) and traffic.

CONCLUSIONS

We found protective associations by green space on birth outcomes. Increasing green space and/or reducing urban space (e.g. the greening of city environments) may reduce the risk of adverse birth outcomes such as LBW and SGA. Populations living in urban environments will grow in the next half century, and allocation of green space among urban areas may play a critical role for public health in urban planning.

Recent Updates in the Social and Environmental Determinants of Sleep Health

In this brief review article, we provide an overview of recent (since 2010) scientific contributions to our understanding of the social and environmental determinants of sleep health. In particular, we focus on three areas where we saw the most contributions to the determinants of sleep health among children, adolescents, and adults. First, studies of neighborhood context and sleep health find that sleep quality and quantity are lower in disadvantaged neighborhoods. These negative associations are often stronger for women than for men. Second, family factors matter for sleep health. Children from families with more parental resources sleep better than do children from families without such resources. Adults with children sleep less than those without, and work-family conflict is an impediment to good sleep. Third, media use is problematic for sleep health. Around the world, higher levels of screen media use are associated with lower quality and quantity of sleep. Future research on the social and environmental determinants of sleep health will grow out of these three areas of current research. In addition, we anticipate new research in the international realm and in the area of interventions designed to improve the population's sleep health.

The Association of Urbanicity with Cognitive Development at Five Years of Age in Preterm Children

Objective

To determine the association of urbanicity, defined as living in an urban area, with cognitive development at five years of age in preterm children who were free of any disabilities or neurodevelopmental delays.

Design

Prospective population-based cohort.

Setting

French regional Loire Infant Follow-up Team (LIFT) network.

Participants

Included in the study were 1738 surviving infants born between March 2003 and December 2008 before 35 weeks of gestational age. At two years of age, the children were free of any disabilities and neurodevelopmental delays and were living in the Pays de la Loire region from their birth to five years of age.

Main Outcome Measures

The cognitive development at five years of age was evaluated with the Global School Adaptation score (GSA). The urbanicity of the residence for each child was classified into three groups: urban, quasi-rural, and rural area.

Results

Quantile regression approaches were used to identify a significant association between urbanicity and the GSA score at five years of age (adjusting for child and family characteristics). We found that the negative impact of urbanicity on the GSA score was more important for the lower quantile of the GSA scores.

Conclusions

Urbanicity was significantly associated with cognitive neurodevelopment at five years of age in preterm children born before 35 weeks of gestation. Complementary results additionally suggest that this relation could be mediated at the residence level by a high socioeconomic deprivation level. If these results are confirmed, more personalized follow-ups could be developed for preterm children. Further studies are needed to finely identify the contextual characteristics of urbanicity that underlie this association.

Categorisation of built environment characteristics: the trouble with tertiles

Background

In the analysis of the effect of built environment features on health, it is common for researchers to categorise built environment exposure variables based on arbitrary percentile cut-points, such as median or tertile splits. This arbitrary categorisation leads to a loss of information and a lack of comparability between studies since the choice of cut-point is based on the sample distribution.

Discussion

In this paper, we highlight the various drawbacks of adopting percentile categorisation of exposure variables. Using data from the SocioEconomic Status and Activity in Women (SESAW) study from Melbourne, Australia, we highlight alternative approaches which may be used instead of percentile categorisation in order to assess built environment effects on health. We discuss these approaches using an example which examines the association between the number of accessible supermarkets and body mass index.

Summary

We show that alternative approaches to percentile categorisation, such as transformations of the exposure variable or factorial polynomials, can be implemented easily using standard statistical software packages. These procedures utilise all of the available information available in the data, avoiding a loss of power as experienced when categorisation is adopted.We argue that researchers should retain all available information by using the continuous exposure, adopting transformations where necessary.

Natural environments, ancestral diets, and microbial ecology: is there a modern "paleo-deficit disorder"? Part I

Famed microbiologist René J. Dubos (1901-1982) was an early pioneer in the developmental origins of health and disease (DOHaD) construct. In the 1960s, he conducted groundbreaking experimental research concerning the ways in which early-life experience with nutrition, microbiota, stress, and other environmental variables could influence later-life health outcomes. He also wrote extensively on potential health consequences of a progressive loss of contact with natural environments (now referred to as green or blue space), arguing that Paleolithic experiences have created needs, particularly in the mental realm, that might not be met in the context of rapid global urbanization. He posited that humans would certainly adapt to modern urban landscapes and high technology, but there might be a toll to be paid in the form of higher psychological distress (symptoms of anxiety and depression) and diminished quality of life. In particular, there might be an erosion of humanness, exemplified by declines in altruism/empathy. Here in the first of a two-part review, we examine contemporary research related to natural environments and question to what extent Dubos might have been correct in some of his 50-year-old assertions.

Perceived neighborhood safety and sleep quality: a global analysis of six countries

OBJECTIVE

Building on previous North American and European studies of neighborhood context and sleep quality, we tested whether several self-reported sleep outcomes (sleep duration, insomnia symptoms, sleepiness, lethargy, and overall sleep quality) vary according to the level of perceived neighborhood safety in six countries: Mexico, Ghana, South Africa, India, China, and Russia.

METHODS

Using data (n = 39,590) from Wave I of the World Health Organization's Longitudinal Study on Global Ageing and Adult Health (2007-2010), we estimated a series of multinomial and binary logistic regression equations to model each sleep outcome within each country.

RESULTS

Taken together, our results show that respondents who feel safe from crime and violence in their neighborhoods tend to exhibit more favorable sleep outcomes than respondents who feel less safe. This general pattern is especially pronounced in China and Russia, moderately evident in Mexico, Ghana, and South Africa, and sporadic in India. Perceptions of neighborhood safety are strongly associated with insomnia symptoms and poor sleep quality (past 30 days), moderately associated with sleepiness, lethargy, and poor sleep quality (past 2 days), and inconsistently associated with sleep duration (past two days).

CONCLUSIONS

We show that perceived neighborhood safety is associated with more favorable self-reported sleep outcomes in six understudied countries. Additional research is needed to replicate our findings using longitudinal data, more reliable neighborhood measures, and more direct measures of sleep quality in these and other regions of the world.

Growing Right Onto Wellness (GROW): a family-centered, community-based obesity prevention randomized controlled trial for preschool child-parent pairs

Growing Right Onto Wellness (GROW) is a randomized controlled trial that tests the efficacy of a family-centered, community-based, behavioral intervention to prevent childhood obesity among preschool-aged children. Focusing on parent-child pairs, GROW utilizes a multi-level framework, which accounts for macro (i.e., built-environment) and micro (i.e., genetics) level systems that contribute to the childhood obesity epidemic. Six hundred parent-child pairs will be randomized to a 3-year healthy lifestyle intervention or a 3-year school readiness program. Eligible children are enrolled between ages 3 and 5, are from minority communities, and are not obese. The principal site for the GROW intervention is local community recreation centers and libraries. The primary outcome is childhood body mass index (BMI) trajectory at the end of the three-year study period. In addition to other anthropometric measurements, mediators and moderators of growth are considered, including genetics, accelerometry, and diet recall. GROW is a staged intensity intervention, consisting of intensive, maintenance, and sustainability phases. Throughout the study, parents build skills in nutrition, physical activity, and parenting, concurrently forming new social networks. Participants are taught goal-setting, self-monitoring, and problem solving techniques to facilitate sustainable behavior change. The GROW curriculum uses low health literacy communication and social media to communicate key health messages. The control arm is administered to both control and intervention participants. By conducting this trial in public community centers, and by implementing a family-centered approach to sustainable healthy childhood growth, we aim to develop an exportable community-based intervention to address the expanding public health crisis of pediatric obesity.