Natural history of sleep disordered breathing in prepubertal children transitioning to adolescence

Racial/ethnic disparities in the trajectories of insomnia symptoms from childhood to young adulthood

STUDY OBJECTIVES

To examine differences in the longitudinal prevalence of childhood insomnia symptoms across black/African American, Hispanic/Latinx, and non-Hispanic white groups.

METHODS

Participants were 519 children from the Penn State Child Cohort (baseline [V1] from 2000-2005) who were followed up 8 years later as adolescents (V2) and 15 years later as young adults (S3). Mean age at S3 was 24.1 ± 2.7 years. Approximately, 76.5% identified as non-Hispanic white, 12.9% as black/African American, 7.1% as Hispanic/Latinx, and 3.5% as "other" race/ethnicity. Insomnia symptoms were defined as parent-reported (childhood) or self-reported (adolescence and young adulthood) moderate-to-severe difficulties initiating/maintaining sleep. Longitudinal trajectories of insomnia symptoms were identified across three-time points and the odds of each trajectory were compared between racial/ethnic groups, adjusting for sex, age, overweight, sleep apnea, periodic limb movements, psychiatric/behavioral disorders, and psychotropic medication use.

RESULTS

Black/African Americans compared to non-Hispanic whites were at significantly higher odds of having a childhood-onset persistent trajectory through young adulthood (OR = 2.58, 95% CI [1.29, 5.14]), while Hispanics/Latinx were at nonsignificantly higher odds to have the same trajectory (OR = 1.81, 95% CI [0.77, 4.25]). No significant racial/ethnic differences were observed for remitted and waxing-and-waning trajectories since childhood or incident/new-onset trajectories in young adulthood.

CONCLUSIONS

The results indicate that disparities in insomnia symptoms among black/African American and, to a lesser extent, Hispanic/Latinx groups start early in childhood and persist into young adulthood. Identifying and intervening upon upstream determinants of racial/ethnic insomnia disparities are warranted to directly address these disparities and to prevent their adverse health sequelae.

CLINICAL TRIAL INFORMATION

N/A; Not a clinical trial.

Edward O. Bixler, PhD: from the Apollo project and chimpanzees to sleep epidemiology

What an honor to write about Dr. Edward O. Bixler's contributions to the sleep field. In 1967, Dr. Bixler published a case report on a chimpanzee with implanted brain electrodes while working at an Air Force base in New Mexico. A few years later, in 1971, he published on the sleep effects of flurazepam in individuals with insomnia together with Dr. Anthony Kales, data that he had collected when the Sleep Research & Treatment Center (SRTC) was housed at the University of California Los Angeles. Dr. Bixler, a meticulous scientist, learned from Dr. Kales, a devoted clinician, to study "the whole patient, and all aspects of sleep," a legacy that continued when the SRTC moved to Penn State in Hershey. Indeed, Dr. Bixler's tenure at Penn State from 1971 until 2019 kept the science of the SRTC focused on that premise and helped translate scientific evidence into clinical care. He not only contributed early to the pharmacology of sleep and the effects of hypnotics, but he was also a pioneer in "sleep epidemiology." His "Prevalence of sleep disorders in the Los Angeles metropolitan area" study of 1979 was the first rigorous epidemiological study on sleep disturbances. Starting in 1990, he established the Penn State Adult Cohort to estimate the prevalence and natural history of sleep-disordered breathing and other sleep disorders in adults. Inspired by life-course epidemiology, he established in 2001 the Penn State Child Cohort to estimate the same phenomena in children. This Living Legend paper captures and highlights Dr. Bixler's enduring legacy to sleep science.

Early life predictors of obstructive sleep apnoea in young adults: Insights from a longitudinal community cohort (Raine study)

OBJECTIVE

Early-life obstructive sleep apnoea (OSA) predictors are unavailable for young adults. This study identifies early-life factors predisposing young adults to OSA.

METHODS

This retrospective study included 923 young adults and their mothers from the Western Australian Pregnancy Raine Study Cohort. OSA at 22 years was determined from in-laboratory polysomnography. Logistic regression was used to identify maternal and neonatal factors associated with OSA in young adulthood.

RESULTS

OSA was observed in 20.8% (192) participants. Maternal predictors of OSA included gestational diabetes mellitus (odds ratio (OR) 9.54, 95% confidence interval (CI) 1.7, 58.5, P = 0.011), preterm delivery (OR 3.18, 95%CI 1.1,10.5, P = 0.043), preeclampsia (OR 2.95, 95%CI 1.1,8.0, P = 0.034), premature rupture of membranes (OR 2.46, 95%CI 1.2, 5.2, P = 0.015), age ≥35 years (OR 2.28, 95%CI 1.2,4.4, P = 0.011), overweight and obesity (pregnancy BMI≥25 kg/m2) (OR 2.00, 95%CI 1.2,3.2, P = 0.004), pregnancy-induced hypertension (OR 1.89, 95%CI 1.1,3.2, P = 0.019), and Chinese ethnicity (OR 2.36,95%CI 1.01,5.5, P = 0.047). Neonatal predictors included male child (OR 2.10, 95%CI 1.5,3.0, P < 0.0001), presence of meconium-stained liquor during delivery (OR 1.60, 95%CI 1.0,2.5, P = 0.044) and admission to special care nursery (OR 1.51 95%CI 1.0,2.2, P = 0.040). Higher birth lengths reduced OSA odds by 7% for each centimetre (OR 0.93, 95%CI 0.87, 0.99, P = 0.033).

CONCLUSIONS

A range of maternal and neonatal factors predict OSA in young adults, including those related to poor maternal metabolic health, high-risk pregnancy and stressful perinatal events. This information could assist in the early identification and management of at-risk individuals and indicates that better maternal health may reduce the likelihood of young adults developing OSA.

Objective and subjective measures of sleep initiation are differentially associated with DNA methylation in adolescents

INTRODUCTION

The onset of puberty is associated with a shift in the circadian timing of sleep, leading to delayed sleep initiation [i.e., later sleep onset time (SOT)] due to later bedtimes and/or longer sleep onset latency (SOL). Several genome-wide association studies (GWAS) have identified genes that may be involved in the etiology of sleep phenotypes. However, circadian rhythms are also epigenetically regulated; therefore, epigenetic biomarkers may provide insight into the physiology of the pubertal sleep onset shift and the pathophysiology of prolonged or delayed sleep initiation.

RESULTS

The gene-wide analysis indicated differential methylation within or around 1818 unique genes across the sleep initiation measurements using self-report, actigraphy (ACT), and polysomnography (PSG), while GWAS-informed analysis yielded 67 genes. Gene hits were identified for bedtime (PSG), SOL (subjective, ACT and PSG) and SOT (subjective and PSG). DNA methylation within 12 genes was associated with both subjective and PSG-measured SOL, 31 with both ACT- and PSG-measured SOL, 19 with both subjective and ACT-measured SOL, and one gene (SMG1P2) had methylation sites associated with subjective, ACT- and PSG-measured SOL.

CONCLUSIONS

Objective and subjective sleep initiation in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian phenotypes. Additionally, our data provide evidence for a potential epigenetic link between habitual (subjective and ACT) SOL and in-lab SOT and DNA methylation in and around genes involved in circadian regulation (i.e., RASD1, RAI1), cardiometabolic disorders (i.e., FADS1, WNK1, SLC5A6), and neuropsychiatric disorders (i.e., PRR7, SDK1, FAM172A). If validated, these sites may provide valuable targets for early detection and prevention of disorders involving prolonged or delayed SOT, such as insomnia, delayed sleep phase, and their comorbidity.

Short-term and intermediate-term fine particulate air pollution are synergistically associated with habitual sleep variability in adolescents - A cross-sectional study

BACKGROUND

Both air pollution and poor sleep have been associated with increased risk of cardiovascular diseases. However, the association between air pollution and sleep health, especially among adolescents, is rarely investigated.

METHODS

To investigate the association between fine particulate (PM2.5) air pollution and habitual sleep patterns, we analyzed data obtained from 246 adolescents who participated in the Penn State Child Cohort follow-up examination. We collected their individual-level 24-h (short-term) PM2.5 concentration by using a portable monitor. We estimated their residential-level PM2.5 concentration during the 60-day period prior to the examination (intermediate-term) using a kriging approach. Actigraphy was used to measure participants' sleep durations for seven consecutive nights. Habitual sleep duration (HSD) and sleep variability (HSV) were calculated as the mean and SD of the seven-night sleep duration. Multivariable-adjusted linear regression models were used to assess the association between PM2.5 exposures and HSD/HSV. An interaction between short-term and intermediate-term PM2.5 was created to explore their synergistic associations with HSD/HSV.

RESULTS

Elevated short-term and intermediate-term PM2.5 exposure were significantly (p < 0.05) associated with higher HSV, but not HSD. Specifically, the mean (95% CI) increase in HSV associated with 1 SD higher 24-h (26.3 μg/m3) and 60-day average (2.2 μg/m3) PM2.5 were 14.6 (9.4, 14.8) and 4.9 (0.5, 9.2) minutes, respectively. In addition, there was a synergistic interaction (p = 0.08) between short-term and intermediate-term PM2.5 exposure on HSV, indicative that the association between intermediate-term PM2.5 and HSV became stronger as short-term PM2.5 increases, and vice versa.

CONCLUSION

Short-term individual-level and intermediate-term residential-level PM2.5 exposures are adversely and synergistically associated with increased sleep variability, an indicator of instability of sleep quantity, in adolescents. Through such an association with sleep pattern, PM2.5 air pollution may increase long-term cardiometabolic risks.

Acute Impact of Fine Particulate Air Pollution on Cardiac Arrhythmias in a Population‐Based Sample of Adolescents: The Penn State Child Cohort

Background

Fine particulate (fine particles with aerodynamic diameters ≤2.5 μm [PM 2.5 ]) exposure has been associated with a risk of cardiac arrhythmias in adults. However, the association between PM 2.5 exposure and cardiac arrhythmias in adolescents remains unclear.

Methods and Results

To investigate the association and time course between PM 2.5 exposure with cardiac arrhythmias in adolescents, we analyzed the data collected from 322 adolescents who participated in the PSCC (Penn State Child Cohort) follow‐up examination. We obtained individual‐level 24‐hour PM 2.5 concentrations with a nephelometer. Concurrent with the PM 2.5 measure, we obtained 24‐hour ECG data using a Holter monitor, from which cardiac arrhythmias, including premature atrial contractions and premature ventricular contractions (PVCs), were identified. PM 2.5 concentration and numbers of premature atrial contractions/PVCs were summarized into 30‐minute‐based segments. Polynomial distributed lag models within a framework of a negative binomial model were used to assess the effect of PM 2.5 concentration on numbers of premature atrial contractions and PVCs. PM 2.5 exposure was associated with an acute increase in number of PVCs. Specifically, a 10 μg/m 3 increase in PM 2.5 concentration was associated with a 2% (95% CI, 0.4%–3.3%) increase in PVC counts 0.5 to 1.0, 1.0 to 1.5, and 1.5 to 2.0 hours after the exposure. Cumulatively, a 10 μg/m 3 increment in PM 2.5 was associated with a 5% (95% CI, 1%–10%) increase in PVC counts within 2 hours after exposure. PM 2.5 concentration was not associated with premature atrial contraction.

Conclusions

PM 2.5 exposure was associated with an acute increased number of ventricular arrhythmias in a population‐based sample of adolescents. The time course of the effect of PM 2.5 on ventricular arrhythmia is within 2 hours after exposure.

Behavioral, neurocognitive, polysomnographic and cardiometabolic profiles associated with obstructive sleep apnea in adolescents with ADHD

BACKGROUND

A high comorbidity between attention-deficit/hyperactivity disorder (ADHD) and obstructive sleep apnea (OSA) as well as similar impairments across neurobehavioral outcomes has been described in children. However, there is a paucity of research examining the comorbidity of these two disorders in adolescents. This study examined the association of OSA with sleep, neurobehavioral, and cardiometabolic outcomes in adolescents with ADHD from the general population.

METHODS

421 adolescents (16.9 ± 2.3 years, 53.9% male) underwent 9-hr polysomnography, neurobehavioral, and physical evaluation. ADHD was ascertained by a parent-or-self-report of a lifetime diagnosis/treatment of ADHD. OSA was defined as an apnea hypopnea index of ≥2 events/hour. Groups of controls (n = 208), OSA-alone (n = 115), ADHD-alone (n = 54), and ADHD+OSA (n = 44) were studied. Multivariable-adjusted general linear models tested group differences in PSG parameters, neurobehavioral, and cardiometabolic outcomes after controlling for sex, race/ethnicity, age, and/or body mass index percentile.

RESULTS

The ADHD+OSA group had significantly longer sleep onset latency, shorter total sleep time, lower sleep efficiency, and higher percent of stage 1 sleep, as compared with all other groups, however, these differences were diminished by excluding adolescents on psychoactive medication. The ADHD-alone group showed significantly higher periodic limb movements than controls. The ADHD+OSA and ADHD-alone groups did not significantly differ on any measure of neurocognitive or behavioral functioning. The ADHD+OSA and OSA-alone groups showed significantly worse cardiometabolic and inflammatory biomarkers when compared to controls or the ADHD-alone, but did not significantly differ between each other.

CONCLUSIONS

Adolescents with a diagnosis ADHD+OSA showed phenotypic risk factors for OSA (i.e., overweight/obesity, visceral adiposity, metabolic syndrome, and inflammation) but not worse neurobehavioral outcomes when compared with ADHD-alone. While comorbidity is possible, these data support that adolescents with a suspicion of ADHD should be screened for OSA, before a diagnosis is reached and psychoactive medication initiated.

Association of a novel EEG metric of sleep depth/intensity with attention-deficit/hyperactivity, learning, and internalizing disorders and their pharmacotherapy in adolescence

STUDY OBJECTIVES

Psychiatric/learning disorders are associated with sleep disturbances, including those arising from abnormal cortical activity. The odds ratio product (ORP) is a standardized electroencephalogram metric of sleep depth/intensity validated in adults, while ORP data in youth are lacking. We tested ORP as a measure of sleep depth/intensity in adolescents with and without psychiatric/learning disorders.

METHODS

Four hundred eighteen adolescents (median 16 years) underwent a 9-hour, in-lab polysomnography. Of them, 263 were typically developing (TD), 89 were unmedicated, and 66 were medicated for disorders including attention-deficit/hyperactivity (ADHD), learning (LD), and internalizing (ID). Central ORP during non-rapid eye movement (NREM) sleep was the primary outcome. Secondary/exploratory outcomes included central and frontal ORP during NREM stages, in the 9-seconds following arousals (ORP-9), in the first and second halves of the night, during REM sleep and wakefulness.

RESULTS

Unmedicated youth with ADHD/LD had greater central ORP than TD during stage 3 and in central and frontal regions during stage 2 and the second half of the sleep period, while ORP in youth with ADHD/LD on stimulants did not significantly differ from TD. Unmedicated youth with ID did not significantly differ from TD in ORP, while youth with ID on antidepressants had greater central and frontal ORP than TD during NREM and REM sleep, and higher ORP-9.

CONCLUSIONS

The greater ORP in unmedicated youth with ADHD/LD, and normalized levels in those on stimulants, suggests ORP is a useful metric of decreased NREM sleep depth/intensity in ADHD/LD. Antidepressants are associated with greater ORP/ORP-9, suggesting these medications induce cortical arousability.

Evaluation of obesity and asthma as risk factors for moderate to severe obstructive sleep apnea in children

STUDY OBJECTIVES

Asthma and obesity are risk factors for obstructive sleep apnea (OSA) in children but their link to OSA severity is uncertain. We aimed at determining whether asthma or obesity were associated with an increased risk of moderate/severe OSA.

METHODS

Children undergoing a one-night polysomnography for suspicion of OSA were retrospectively included. Univariate and multivariate analyses were conducted to assess the clinical and demographic characteristics linked to moderate/severe OSA (obstructive apnea-hypopnea index ≥ 5/h of sleep) with odds ratio (OR) and 95% confidence interval reported.

RESULTS

490 children (311 (64%) boys) were included with a median [25th; 75th percentile] age of 8.7 [5.4; 12.9] years, 164 (33%) non-asthmatics non-obese, 122 (25%) obese non-asthmatics, 125 (26%) asthmatics non-obese, 79 (16%) asthmatics and obese. Moderate/severe OSA was present in 157 (32%) children (75/157 (48%) obese and 52/157 (33%) asthmatics). Independent factors associated with increased or decreased risk of moderate/severe OSA were: obesity and male sex (OR 1.82 [1.16; 2.87], P = 0.01, and 1.55 [1.02; 2.36], P = 0.04, respectively), and current asthma, age >6 years or behavioral disorders (OR 0.45 [0.29; 0.70], P < 0.001; 0.44 [0.27; 0.73], P < 0.001; and 0.55 [0.33; 0.92], P = 0.02, respectively). Abnormal resistance of the respiratory system (measured in 241 children), but not abnormal spirometry (measured in 213 children), increased the risk of moderate/severe OSA (OR 2.95 [1.46-5.96], P = 0.003).

CONCLUSIONS

In our cohort enriched in obese and asthmatic children, obesity was associated with higher risk of moderate/severe OSA whereas current asthma was not.

Trajectories of Insomnia Symptoms From Childhood Through Young Adulthood

OBJECTIVES

Insomnia symptoms are transdiagnostic to physical and mental health disorders. Given the lack of population-based cohorts with objective sleep measures and long-term follow-ups, little is known about the chronicity of childhood insomnia symptoms. We determined the developmental trajectories of insomnia symptoms, their evolution into adult insomnia, and the role of objective sleep duration in the transition to adulthood.

METHODS

A total of 502 children (median 9 years old, 71.7% response rate) were studied 7.4 years later as adolescents (median 16 years old) and 15 years later as adults (median 24 years old). Insomnia symptoms were ascertained as moderate-to-severe difficulties initiating and/or maintaining sleep via parent- or self reports at all 3 time points, adult insomnia via self-report in young adulthood, and objective short-sleep duration via polysomnography in childhood and adolescence.

RESULTS

Among children with insomnia symptoms, the most frequent trajectory was persistence (43.3%), followed by remission (26.9% since childhood, 11.2% since adolescence) and a waxing-and-waning pattern (18.6%). Among children with normal sleep, the most frequent trajectory was persistence (48.1%), followed by developing insomnia symptoms (15.2% since adolescence, 20.7% in adulthood) and a waxing-and-waning pattern (16.0%). The odds of insomnia symptoms worsening into adult insomnia (22.0% of children, 20.8% of adolescents) were 2.6-fold and 5.5-fold among short-sleeping children and adolescents, respectively.

CONCLUSIONS

Early sleep interventions are a health priority because pediatricians should not expect insomnia symptoms to developmentally remit in a high proportion of children. Objective sleep measures may be clinically useful in adolescence, a critical period for the adverse prognosis of the insomnia with short-sleep duration phenotype.

Evidence of a maturational disruption in non-rapid eye movement sleep slow wave activity in youth with attention-deficit/hyperactivity, learning and internalizing disorders

BACKGROUND

Sleep slow wave activity (SWA) peaks during childhood and declines in the transition to adolescence during typical development (TD). It remains unknown whether this trajectory differs in youth with neuropsychiatric disorders.

METHODS

We analyzed sleep EEGs of 664 subjects 6 to 21 y (449 TD, 123 unmedicated, 92 medicated) and 114 subjects 7-12 y (median 10.5 y) followed-up at 18-22 y (median 19 y). SWA (0.4-4 Hz) power was calculated during non-rapid eye movement sleep.

RESULTS

TD and unmedicated youth showed cubic central and frontal SWA trajectories from 6 to 21 y (p-cubic<0.05), with TD youth showing peaks in central SWA at 6.8 y and frontal at 8.2 y. Unmedicated attention-deficit/hyperactivity (ADHD) and/or learning disorders (LD) showed peak central SWA 2 y later (at 9.6 y, coinciding with peak frontal SWA) than TD, followed by a 67% steeper slope by 19 y. Frontal SWA peak and slope in unmedicated ADHD/LD, and that of central and frontal in internalizing disorders (ID), were similar to TD. Unmedicated ADHD/LD did not differ in the longitudinal SWA percent change by 18-22 y; unmedicated ID showed a lower longitudinal change in frontal SWA than TD. Medicated youth showed a linear decline in central and frontal SWA from 6 to 21 y (p-linear<0.05).

CONCLUSIONS

ADHD/LD youth show a maturational delay and potential topographical disruption in SWA during childhood and steeper decline throughout adolescence, suggesting faster synaptic pruning. Youth with ID experience less changes in frontal SWA by late adolescence. Psychotropic medications may impact the maturational trajectory of SWA, but not the magnitude of developmental decline by late adolescence.

[Diagnostic criteria for obstructive sleep apnea syndrome in adolescent]

The obstructive sleep apnoea syndrome (OSAS) affects 1-4% of adolescents. It represents a transitional stage between paediatric and adult OSA and is characterized by specific symptoms. BACKGROUND: The persistence of childhood OSAS during adolescence is not frequent. Risk factors are male sex, obesity and a history of tonsillectomy or adenoidectomy. Symptoms may be misleading such as tiredness and depressive disorders. In adolescence, untreated OSAS may result in neuro-behavioural and cognitive deficits, systemic inflammation, cardiovascular and metabolic disorders. The French Society of Research and Sleep Medicine organized a meeting on OSAS in adolescents. A multidisciplinary group of specialists (pulmonologists, pediatricians, ENT and maxillo-facial surgeons, dentofacial orthopedists/orthodontists, myofunctional therapists and sleep specialists) exchanged their experience, discussed publications and drew up a consensus document on the diagnosis and polysomnographic criteria for OSAS in adolescents. They proposed a practical diagnostic guideline and follow-up for these adolescents. OUTLOOK AND CONCLUSION: A good knowledge of the particularities of this pathology by the physician will lead to an early diagnosis, propose adapted multifactorial treatments and avoid the deleterious consequences of this pathology at adult age.

Sex and Pubertal Differences in the Maturational Trajectories of Sleep Spindles in the Transition from Childhood to Adolescence: A Population-Based Study

Sleep spindles, bursts of electroencephalogram (EEG) activity in the σ-frequency (11–16 Hz) range, may be biomarkers of cortical development. Studies capturing the transition to adolescence are needed to delineate age-related, sex-related, and pubertal-related changes in sleep spindles at the population-level. We analyzed the sleep EEG of 572 subjects 6–21 years (48% female) and 332 subjects 5–12 years (46% female) followed-up at 12–22 years. From 6 to 21 years, spindle density (p quadratic = 0.019) and fast (12–16 Hz) spindle percent (p quadratic = 0.016) showed inverted U-shaped trajectories, with plateaus after 15 and 19 years, respectively. Spindle frequency increased (p linear < 0.001), while spindle power decreased (p linear < 0.001) from 6 to 21 years. The trajectories of spindle density, frequency, and fast spindle percent diverged between females and males, in whom density plateaued by 14 years, fast spindle percent by 16 years, and frequency by 18 years, while fast spindle percent and spindle frequency continued to increase until 21 years in females. Males experienced a longitudinal increase in spindle density 31% greater than females by 12–14 years (p = 0.006). Females experienced an increase in spindle frequency and fast spindle percent 2% and 41% greater, respectively, than males by 18–22 years (both p = 0.004), while males experienced a 14% greater decline in spindle power by 18–22 years (p = 0.018). Less mature adolescents (86% male) experienced a longitudinal increase in spindle density 36% greater than mature adolescents by 12–14 years (p = 0.002). Overall, males experience greater maturational changes in spindle density in the transition to adolescence, driven by later pubertal development, and sex differences become prominent in early adulthood when females have greater spindle power, frequency, and fast spindle percent.

Muscle type of palatopharyngeal muscle in children with severe obstructive sleep apnea

STUDY OBJECTIVES

To investigate the fiber-type distribution in palatopharyngeal muscle via adenosine triphosphatase and quantitative real-time polymerase chain reaction in children with severe obstructive sleep apnea (OSA).

METHODS

Study participants were 12 children with severe OSA and 15 children with simple snoring as the control group. Both groups were diagnosed by polysomnography and treated with tonsillectomy. The samples of palatopharyngeus muscle were studied under adenosine triphosphatase staining and quantitative real-time polymerase chain reaction to classify the different fiber types.

RESULTS

There were no differences in baseline age, body mass index, tonsil size, or sleep stage constitution between the 2 groups. Dominance (>60%) of type I fiber was observed both in children with simple snoring (3/15, 20%) and in those with severe OSA (1/12, 8.3%) via adenosine triphosphatase staining. Predominance of type II fibers was seen in 3/15 (20%) in the control group and 6/12 (50%) in the severe OSA group, respectively. Type grouping was also seen in 8/15 (53.3%) in non-OSA and 6/12 (50%) in severe OSA groups, respectively. There was no difference in distribution of subtype fibers assessed by quantitative real-time polymerase chain reaction between the 2 groups; the mean percentages of type I fibers were 25.8% ± 19.5% and 20.9% ± 16.6%, respectively (P > .05), similar to type IIa fibers (35.2% ± 23.4% and 40.9% ± 28.8%) (P > .05). There was a decrease in the percentage of type I fibers between children younger and older than 12 years (P < 0.05), although this was not due to OSA (P > 0.05).

CONCLUSIONS

There were no specific changes via adenosine triphosphatase staining or a difference in distribution of subtype fibers via quantitative real-time polymerase chain reaction between children with severe pediatric OSA and those with simple snoring, whereas the percentage of type I fiber decreased dynamically due to age but not OSA.

CLINICAL TRIAL REGISTRATION

Registry: Chinese Clinical Trials Registry; Name: A study of the mechanism of the conversion of upper airway expasion muscle's fiver types of OSA patient which may be mediated by estrogen-related receptor alpha; URL: https://www.chictr.org.cn/showproj.aspx?proj=6144; Identifier: ChiCTR-CCC-13003415.

Association of Pediatric Obstructive Sleep Apnea With Elevated Blood Pressure and Orthostatic Hypertension in Adolescence

Importance

Although pediatric guidelines have delineated updated thresholds for elevated blood pressure (eBP) in youth and adult guidelines have recognized obstructive sleep apnea (OSA) as an established risk factor for eBP, the relative association of pediatric OSA with adolescent eBP remains unexplored.

Objective

To assess the association of pediatric OSA with eBP and its orthostatic reactivity in adolescence.

Design, Setting, and Participants

At baseline of this population-based cohort study (Penn State Child Cohort) in 2000-2005, a random sample of 700 children aged 5 to 12 years from the general population was studied. A total of 421 participants (60.1%) were followed up in 2010-2013 after 7.4 years as adolescents (ages, 12-23 years). Data analyses were conducted from July 6 to October 29, 2020.

Main Outcomes and Measures

Outcomes were the apnea-hypopnea index (AHI) score, ascertained via polysomnography conducted in a laboratory; eBP measured in the seated position identified using guideline-recommended pediatric criteria; orthostatic hyperreactivity identified with BP assessed in the supine and standing positions; and visceral adipose tissue assessed via dual-energy x-ray absorptiometry.

Results

Among the 421 participants (mean [SD] age at follow-up, 16.5 [2.3] years), 227 (53.9%) were male and 92 (21.9%) were racial/ethnic minorities. A persistent AHI of 2 or more since childhood was longitudinally associated with adolescent eBP (odds ratio [OR], 2.9; 95% CI 1.1-7.5), while a remitted AHI of 2 or more was not (OR, 0.9; 95% CI 0.3-2.6). Adolescent OSA was associated with eBP in a dose-response manner; however, the association of an AHI of 2 to less than 5 among adolescents was nonsignificant (OR, 1.5; 95% CI, 0.9-2.6) and that of an AHI of 5 or more was approximately 2-fold (OR, 2.3; 95% CI, 1.1-4.9) after adjusting for visceral adipose tissue. An AHI of 5 or more (OR, 3.1; 95% CI, 1.2-8.5), but not between 2 and less than 5 (OR, 1.3; 95% CI, 0.6-3.0), was associated with orthostatic hyperreactivity among adolescents even after adjusting for visceral adipose tissue. Childhood OSA was not associated with adolescent eBP in female participants, while the risk of OSA and eBP was greater in male participants.

Conclusions and Relevance

The results of this cohort study suggest that childhood OSA is associated with adolescent hypertension only if it persists during this developmental period. Visceral adiposity explains a large extent of, but not all, the risk of hypertension associated with adolescent OSA, which is greater in male individuals.

Maturational trajectories of non-rapid eye movement slow wave activity and odds ratio product in a population-based sample of youth

BACKGROUND

Brain maturation is reflected in the sleep electroencephalogram (EEG) by a decline in non-rapid eye movement (NREM) slow wave activity (SWA) throughout adolescence and a related decrease in sleep depth. However, this trajectory and its sex and pubertal differences lack replication in population-based samples. We tested age-related changes in SWA (0.4-4 Hz) power and odds ratio product (ORP), a standardized measure of sleep depth.

METHODS

We analyzed the sleep EEG of 572 subjects aged 6-21 y (48% female, 26% racial/ethnic minority) and 332 subjects 5-12 y followed-up at 12-22 y. Multivariable-adjusted analyses tested age-related cross-sectional and longitudinal trajectories of SWA and ORP.

RESULTS

SWA remained stable from age 6 to 10, decreased between ages 11 and 17, and plateaued from age 18 to 21 (p-cubic<0.001); females showed a longitudinal decline 23% greater than males by 13 y, while males experienced a steeper slope after 14 y and their longitudinal decline was 21% greater by 19 y. More mature adolescents (75% female) experienced a greater longitudinal decline in SWA than less mature adolescents by 14 y. ORP showed an age-related increasing trajectory (p-linear<0.001) with no sex or pubertal differences.

CONCLUSIONS

We provide population-level evidence for the maturational decline and sex and pubertal differences in SWA in the transition from childhood to adolescence, while introducing ORP as a novel metric in youth. Along with previous studies, the distinct trajectories observed suggest that age-related changes in SWA reflect brain maturation and local/synaptic processes during this developmental period, while those of ORP may reflect global/state control of NREM sleep depth.

Natural history of insomnia symptoms in the transition from childhood to adolescence: population rates, health disparities, and risk factors

STUDY OBJECTIVES

To determine the sociodemographic, behavioral, and clinical risk factors associated with the persistence, remission, and incidence of insomnia symptoms in the transition from childhood to adolescence.

METHODS

The Penn State Child Cohort is a random, population-based sample of 700 children (5-12 years at baseline), of whom 421 were followed-up as adolescents (12-23 years at follow-up). Subjects underwent polysomnography, clinical history, physical exam, and parent- and self-reported scales at baseline and follow-up. Insomnia symptoms were defined as a parent- or self-report of difficulty falling and/or staying asleep.

RESULTS

The 421 subjects with baseline (Mage = 8.8 years) and follow-up (Mage = 17 years) data were 53.9% male and 21.9% racial/ethnic minorities. The persistence of childhood insomnia symptoms (CIS) was 56% (95% CI = 46.5-65.4), with only 30.3% (95% CI = 21.5-39.0) fully remitting. The incidence of adolescent insomnia symptoms was 31.1% (95% CI = 25.9-36.3). Female sex, racial/ethnic minority, and low socioeconomic status as well as psychiatric/behavioral or neurological disorders, obesity, smoking, and evening chronotype were associated with a higher persistence or incidence of insomnia symptoms.

CONCLUSIONS

CIS are highly persistent, with full remission occurring in only a third of children in the transition to adolescence. Sex-, racial/ethnic-, and socioeconomic-related disparities in insomnia occur as early as childhood, while different mental/physical health and lifestyle/circadian risk factors play a key role in the chronicity of CIS versus their incidence in adolescence. CIS should not be expected to developmentally remit and should become a focus of integrated pediatric/behavioral health strategies.

Racial/ethnic disparity in habitual sleep is modified by caloric intake in adolescents

STUDY OBJECTIVES

We investigated the moderation of caloric intake on the association between race/ethnicity and habitual sleep in adolescents.

METHODS

We analyzed the data obtained from 324 adolescents who completed the follow-up examination of the Penn State Child Cohort study. We collected actigraphy-measured sleep duration on 7 consecutive nights and computed their mean and standard deviation as habitual sleep duration (HSD) and habitual sleep variability (HSV), respectively. We also measured participants' daily intakes of total calorie, total fat, carbohydrates, and protein, through the Youth/Adolescent Food Frequency Questionnaire. Adjusted mean HSD and HSV among non-Hispanic whites and racial/ethnic minorities were compared by using analysis of covariance (ANCOVA), while controlling for age, sex, BMI percentile, total caloric intake, and socioeconomic status. The significance of the interaction between race/ethnicity and caloric intake was further tested in ANCOVA models.

RESULTS

The study sample consisted of 79.3% non-Hispanic whites, 13.0% African American, 4.6% Hispanics, 2.2% Asian, and 0.9% American Indian. Adolescents who are racial/ethnic minorities showed shorter HSD (mean (SE): 6.80 (0.10) vs. 7.07 (0.05) hours/night, p = 0.02) and higher HSV (mean (SE): 1.31 (0.07) vs. 1.15 (0.04) hours/night, p = 0.04) than non-Hispanic whites. Racial/ethnic differences in HSV were significantly more pronounced among adolescents with high caloric intake (p interaction = 0.01), especially from carbohydrates (p interaction = 0.03) and fat (p interaction = 0.05).

CONCLUSION

Adolescents who are racial/ethnic minorities slept objectively shorter and with greater night-to-night variability than non-Hispanic whites. The racial/ethnic disparity in habitual sleep variability was more pronounced among adolescents with high caloric intake, particularly from carbohydrates and fat.

Associations of Sedentary Behaviour, Physical Activity, Cardiorespiratory Fitness and Body Composition with Risk of Sleep-Related Breathing Disorders in Children with Overweight/Obesity: A Cross-Sectional Study

The aim of this study was to examine the associations of sedentary behaviour, physical activity, cardiorespiratory fitness (CRF), and body composition parameters with risk of sleep-related breathing disorders (SRBD) in children with overweight/obesity. One-hundred and nine children (10.0 ± 1.1 years old, 45 girls) with overweight (n = 27) and obesity (n = 82) were included. Television viewing time was self-reported by using the Spanish adaptation of the "Youth Activity Profile" (YAP) questionnaire. Sedentary time and physical activity were measured with accelerometry. CRF was assessed with the 20-m shuttle-run test and body composition parameters with Dual-energy X-ray absorptiometry. SRBD were evaluated by using the Spanish version of the Pediatric Sleep Questionnaire. Television viewing time was positively associated with risk of SRBD (r = 0.222, p = 0.021). CRF was negatively correlated with risk of SRBD (r = -0.210, p = 0.030). Body composition parameters were positively associated with risk of SRBD (all p < 0.05), except fat mass index. Stepwise regression analyses showed that body mass index (BMI) explained the largest proportion of the variance in SRBD (r² = 0.063, p = 0.01) and television viewing time was the only one added after BMI (r² change = 0.048, p = 0.022). This study supports the notion that higher body weight status negatively influences risk of SRBD and adds that unhealthy behaviours could contribute to worsen SRBD, related to an increased risk of cardiovascular diseases. All the significant association observed in this manuscript were of small magnitude, indicating than other factors in addition to the one hereby studied contribute to explain the variance in SRBD.

Association of visceral adiposity and systemic inflammation with sleep disordered breathing in normal weight, never obese adolescents

OBJECTIVE/BACKGROUND

While obesity is a known risk factor for sleep disordered breathing (SDB), a large proportion of children with SDB are not overweight as per body mass index percentile (BMI%) criteria. This study aimed to examine whether premorbid or concurrent adiposity phenotypes and inflammation are associated with SDB in normal weight youth.

PATIENTS/METHODS

A total of 242 persistently non-overweight (BMI%<85) subjects from the Penn State Child Cohort (PSCC, N = 421, 5-12 y at baseline and 12-23 y at follow-up), were studied. The apnea/hypopnea index (AHI) was ascertained via polysomnography (PSG) at both time points. At follow-up, a dual-energy X-ray absorptiometry (DXA) scan assessed android and gynoid distribution and subcutaneous (SAT) and visceral (VAT) adiposity composition, while a fasting blood draw was assayed for C-reactive protein (CRP) and interleukin-6 (IL-6) levels. Multivariable linear regression models with AHI at follow-up as primary outcome were adjusted for sex, race, adenotonsillectomy, age and AHI at baseline.

RESULTS AND CONCLUSIONS

Increased waist circumference (β = 0.227, p = 0.001) at baseline, but not BMI%, neck or hip circumference, was significantly associated with a higher AHI at follow-up. VAT (β = 0.309, p < 0.001), IL-6 (β = 0.243, p < 0.001), SAT (β = 0.235, p = 0.013), CRP (β = 0.221, p = 0.001), and an android distribution (β = 0.196, p = 0.003) at follow-up were significantly associated with a higher AHI at follow-up. Childhood central adiposity predicts SDB in adolescence, even in individuals who have never been overweight since childhood as per BMI criteria. Visceral adiposity and inflammation are concurrent to adolescent SDB, which supports the clinical utility of these biomarkers in predicting its associated cardiometabolic risk.

Childhood OSA is an independent determinant of blood pressure in adulthood: longitudinal follow-up study

BACKGROUND

Current literature supports cross-sectional association between childhood obstructive sleep apnoea (OSA) and elevated blood pressure (BP). However, long-term cardiovascular outcomes in children with OSA remain unexplored.

OBJECTIVE

To evaluate the associations of childhood OSA with BP parameters in a prospective 10 year follow-up study.

METHODS

Participants were recruited from a cohort established for our previous OSA epidemiological study. They were invited to undergo clinical examination, overnight polysomnography and 24-hour ambulatory BP monitoring. Multivariate linear regression was used to assess the associations of baseline childhood OSA with BP outcomes at follow-up. Multivariable log-binomial regression was used with inverse probability weighting to assess the adjusted associations of childhood OSA with hypertension and non-dipping of nocturnal BP in adulthood.

RESULTS

243 participants (59% male) attended the follow-up visit. The mean age was 9.8 (SD ±1.8) and 20.2 (SD ±1.9) years at baseline and follow-up respectively, with a mean follow-up duration of 10.4 (SD ±1.1) years. Childhood moderate-to-severe OSA was associated with higher nocturnal systolic blood pressure (SBP) (difference from normal controls: 6.5 mm Hg, 95% CI 2.9 to 10.1) and reduced nocturnal dipping of SBP (-4.1%, 95% CI -6.3% to 1.8%) at follow-up, adjusted for age, sex, Body Mass Index and height at baseline, regardless of the presence of OSA at follow-up. Childhood moderate-to-severe OSA was also associated with higher risk of hypertension (relative risk (RR) 2.5, 95% CI 1.2 to 5.3) and non-dipping of nocturnal SBP (RR 1.3, 95% CI 1.0 to 1.7) at follow-up.

CONCLUSION

Childhood OSA was found to be an independent risk factor for adverse BP outcomes in adulthood.

High prevalence of periodic limb movements of sleep in children with Down syndrome

STUDY OBJECTIVES

Increased periodic limb movements of sleep (PLMS), > 5 events/h, are present in 1.2% to 7.7% of healthy children and associated with hypertension, attention deficit, and hyperactivity. This study sought to determine the prevalence of elevated PLMS in a large cohort of children with Down syndrome (DS) and their correlation with OSA and ferritin levels.

METHODS

Retrospective chart review of all children with DS ages 2 to 18 years in whom single baseline polysomnography (PSG) was performed at a pediatric hospital over 5 years.

RESULTS

A total of 418 children met inclusion criteria. Three hundred fifty-six children (85%) were referred because of concerns about sleep-disordered breathing; 49 (12%) were referred for screening per American Academy of Pediatrics (AAP) guidelines; and 13 (3%) because of concerns about restless legs or periodic limb movement disorder. One hundred thirty-nine children (33.3%) had elevated PLMS; they were younger (6.3 years) than those without elevated PLMS (7.7 years). OSA was present in 176/418 (42.1%) children, including 13/49 (26.2%) asymptomatic children referred for screening PSG. Ferritin levels were only recorded in the charts of 65 of the children with elevated PLMS (46.7%); in 36 (55.4%) levels were < 50 ng/mL.

CONCLUSIONS

PLMS were increased in a substantial number of this large cohort of children with DS. Additional studies are necessary to assess utility of laboratory testing to predicting PLMS in similar, at-risk, populations. Screening PSG has value in identifying OSA in young, ostensibly asymptomatic children with DS. The prevalence of OSA increased with age in this cohort, unlike in typical children, requiring health care providers to remain vigilant for its emergence across the lifespan.

[Surgical treatment for sleep disorders breathing in children and teenagers]

Adenotonsillectomy is the standard surgery for moderate and severe sleep disorders breathing (SDB) in 2 to 6-year-old children, often due to tonsillar and adenoidal hypertrophy. Recently, partial subtotal intracapsular tonsillotomy has been developed to prevent risks linked to surgery, especially haemorrhages leading to death in extreme cases. Children with apnea, poor quality of life (sleep problems, daytime tiredness), poor academic performance or late growth are candidates for adenotonsillectomy. The management of children with mild SDB is still evolving. Adenotonsillectomy is usually not recommended for adenoidal hypertrophy. Treatment options with mild OSA include watchful waiting, inhaled nasal corticosteroids, and adeno-tonsillectomy. The treatment decision should be made after a discussion between the patient, caregivers and the surgeon regarding the risks and benefits of possible therapies. The surgical procedure is efficient in more than 75% of cases. Close clinical follow-up is necessary, especially in obese children. Primary and secondary haemorrhaging, as well as postoperative pain, are considerably reduced in partial tonsillotomy. Tonsillotomy (intracapsular or subtotal tonsillectomy) is a modern technique because it has been suggested that perioperative pain and postoperative haemorrhage are reduced with the tonsillotomy technique. There is no significant difference in subjective outcome between tonsillotomy and tonsillectomy. These findings may support wider use of tonsillotomy for the treatment of sleep disorders breathing in children. Children with residual disorder may be candidates for surgical procedures such as nasal disobstruction, pharyngoplasty, lingual tonsillectomy or maxillofacial surgery.

Familial Aggregation and Heritability of Obstructive Sleep Apnea Using Children Probands

STUDY OBJECTIVES

Previous studies suggest the presence of familial aggregation of obstructive sleep apnea (OSA) in adults. However, similar data on childhood OSA are limited. This family study aimed to investigate the heritability and familial aggregation of childhood OSA and to examine whether significant differences existed between patients of normal weight and overweight.

METHODS

Children aged 6 to 18 years were recruited as probands either from attendants to sleep clinic (with habitual snoring) or the community (without habitual snoring). Parents and siblings of the probands were also invited to participate. All participants underwent nocturnal sleep study.

RESULTS

A total of 229 probands took part, of whom 33 had moderate to severe OSA, 70 had mild disease, and 126 had no OSA. A total of 412 relatives were also recruited. Although the overall heritability of obstructive apnea-hypopnea index (OAHI) was not significant (h² ± SE = 0.03 ± 0.09, P = .37), it was significant in overweight individuals on subgroup analysis (h² ± SE = 0.43 ± 0.24, P = .032). Significant interaction effect of overweight was demonstrated in both heritability and familial aggregation analyses. Bivariate genetic analysis found that the genetic correlation between OAHI and body mass index in overweight individuals (ρg ± SE = 0.63 ± 0.18) was significantly different from both 0 (P = .005) and 1 (P = .025).

CONCLUSIONS

The differential results of heritability and familial aggregation of OSA in normal weight and overweight subgroups substantiated the recommendation of separating childhood OSA into normal weight and overweight subtypes. In the overweight subgroup, there may be obesity-independent components involved in the genetic variance of OAHI, although a significant proportion of the genetic variance is shared with obesity.

Neurocognitive and behavioral significance of periodic limb movements during sleep in adolescents with attention-deficit/hyperactivity disorder

Study Objectives

The purpose of this study is to examine the association of abnormal periodic limb movements during sleep (PLMS) with neurocognitive and behavioral outcomes in adolescents with attention-deficit/hyperactivity disorder (ADHD) from the general population.

Methods

Four hundred twenty-one adolescents (17.0 ± 2.3 years, 53.9% male) from the Penn State Child Cohort, a random general population sample, underwent 9 hr polysomnography, clinical history, physical examination, neurocognitive evaluation, and completed the Child or Adult Behavioral Checklist (C/ABCL). The presence of ADHD was ascertained by parent- or self-report of receiving a diagnosis of ADHD. PLMS were defined as a PLM index (PLMI) of ≥5 events per hour of sleep.

Results

Adolescents with ADHD (n = 98) had a significantly higher PLMI (5.4 ± 7.3) and prevalence of PLMS (35%) when compared with controls (3.4 ± 5.6, p = 0.006 and 21%, p = 0.004). Significant interactions between ADHD and PLMS showed that adolescents with both disorders (n = 35) were characterized by deficits in control interference, as measured by Stroop test, and elevated internalizing behaviors, as measured by C/ABCL. ADHD severity and externalizing behaviors were elevated in a dose-response manner across ADHD-alone (n = 63) and ADHD + PLMS groups. The association of ADHD with other neurocognitive functions did not vary as a function of PLMS.

Conclusions

PLMS are significantly more frequent in adolescents with ADHD. Importantly, adolescents with both disorders not only have worse neurobehavioral functioning than adolescents with ADHD-alone but specifically presented with executive deficits and anxiety symptoms. These data suggest that PLMS may be a marker of more severe underlying neurobiological deficits in adolescents with ADHD and comorbid internalizing problems.

Childhood high-frequency EEG activity during sleep is associated with incident insomnia symptoms in adolescence

BACKGROUND

Insomnia has been associated in cross-sectional studies with increased beta (15-35 Hz) electroencephalogram (EEG) power during nonrapid eye movement (NREM) sleep, an index of cortical hyperarousal. However, it is unknown whether this cortical hyperarousal is present before individuals with insomnia develop the disorder. To fill this gap, we examined the association of childhood sleep high-frequency EEG activity with incident insomnia symptoms (i.e., absence of insomnia symptoms in childhood but presence in adolescence).

METHODS

We studied a case-control subsample of 45 children (6-11 years) from the Penn State Child Cohort, a population-based random sample of 421 children, who were followed up after 8 years as adolescents (13-20 years). We examined low-beta (15-25 Hz) and high-beta (25-35 Hz) relative power at central EEG derivations during NREM sleep and, in secondary analyses, during sleep onset latency, sleep onset, and REM sleep. Incident insomnia symptoms were defined as the absence of parent-reported difficulty falling and/or staying asleep during childhood and a self-report of these insomnia symptoms during adolescence.

RESULTS

Childhood high-beta power during NREM sleep was significantly increased in children who developed insomnia symptoms in adolescence (n = 25) as compared to normal sleeping controls (n = 20; p = .03). Multivariable-adjusted logistic regression models showed that increased childhood high-beta EEG power during NREM sleep was associated with a threefold increased odds (95% CI = 1.12-7.98) of incident insomnia symptoms in adolescence. No other significant relationships were observed for other sleep/wake states or EEG frequency bands.

CONCLUSIONS

Increased childhood high-frequency EEG power during NREM sleep is associated with incident insomnia symptoms in adolescence. This study indicates that cortical hyperarousal during sleep may be a premorbid neurophysiological sign of insomnia, which may mediate the increased risk of psychiatric disorders associated with insomnia.

[Adolescent obstructive sleep apnoea syndrome: Characteristics and treatment]

Although the prevalence of the obstructive sleep apnoea syndrome (OSAS) is high in adolescents, studies pertaining to adolescent OSAS are less numerous than childhood studies. Cases of adolescent OSAS may consist of residual OSAS after adenotonsillectomy, but most often are de novo cases. Major pathophysiological factors are weight excess or even high-grade obesity, and the association of upper airway narrowing and tonsillar hypertrophy (pharyngeal, palatal or even lingual). ENT and systematic orthodontic assessments are the main points. In case of predisposing factors such as dental, occlusal or dento-facial abnormalities, a specific orthodontic treatment can be discussed. First line treatment is surgical adenotonsillectomy; surgical reduction of the lingual tonsils is seldom required. CPAP treatment may be indicated in the case of severe comorbidities (craniofacial malformations, neuromuscular diseases…) or in obese adolescents with severe residual OSAS. Treatment of adolescent OSAS has to be comprehensive and multidisciplinary, taking into account the specific treatments of obesity and abnormal sleep/wake rhythms.

How OSA Evolves From Childhood to Young Adulthood: Natural History From a 10-Year Follow-up Study

BACKGROUND

Understanding the natural history of childhood OSA can help to determine disease prognosis and to guide risk stratification and management strategies.

METHODS

To evaluate the natural history of childhood OSA and factors associated with spontaneous remission and persistent and incident OSA from childhood to late adolescence/early adulthood, a longitudinal analysis of a prospective community-based cohort was designed. Subjects from a cohort established for an OSA prevalence study were invited to participate in this 10-year follow-up study.

RESULTS

Two hundred and forty-three participants (59% male) took part, and their mean age was 9.8 (SD, ± 1.8) and 20.2 (SD, ± 1.9) years at baseline and follow-up, respectively. The mean follow-up duration was 10.4 (SD, ± 1.1) years. Associations between baseline and follow-up log-transformed obstructive apnea-hypopnea index (OAHI) differed by age; a significant positive association was observed only among participants aged 10 years or older at baseline. Overall polysomnographic remission rate (with OAHI < 1 event/h at follow-up) of childhood OSA was 30%, and 69% had an OAHI < 5 events/h at follow-up. Complete remission of OSA was associated with female sex. Incidence of adolescent/adult OSA with an OAHI ≥ 5 events/h at follow-up was 22%. Male sex and higher baseline BMI z score were associated with incident OSA.

CONCLUSIONS

A proportion of children with OSA, particularly female children, had complete resolution during transition to late adolescence or early adulthood. Childhood and adolescent OSA are distinct entities, with the latter more likely to persist into adulthood. Obesity and male sex are consistent key risk factors for incident OSA.

Childhood obesity, weight loss and developmental trajectories predict the persistence and remission of childhood sleep-disordered breathing

BACKGROUND

Obesity has been recognized as a risk factor for childhood sleep-disordered breathing (SDB), yet it remains unclear how obesity and weight change predict the course of childhood SDB.

OBJECTIVE

The objective of the study is to investigate the role of body weight, upper airway abnormalities and developmental trajectories on the persistence and remission of childhood SDB in the transition to adolescence.

METHODS

The Penn State Child Cohort is a representative population sample of 700 children (5-12 years), of whom 421 were followed up as adolescents (12-23 years). Participants underwent a clinical history, physical examination and polysomnography at both time points.

RESULTS

Obesity and enlarged tonsils were cross-sectionally associated with childhood SDB. Longitudinally, baseline obesity predicted the persistence of childhood SDB (OR = 3.75, 95% CI = 2.00-7.05), while weight loss predicted its remission (OR = 1.67, 95% CI = 1.11-2.50). Children with enlarged tonsils who remitted from SDB had not experienced significant weight loss and only 4.4% had undergone adeno/tonsillectomy. Body fat distribution/composition at follow-up was similar in those who had remitted from childhood SDB as compared with those who had never experienced SDB, while those who persisted with childhood SDB showed significant android distribution and visceral adiposity at follow-up.

CONCLUSIONS

Our data support a causal role for obesity and weight loss in the chronicity and remission, respectively, of childhood SDB in the transition to adolescence and suggest that remission of SDB is related to developmental trajectories of the upper airway in a significant proportion of children. Thus, targeting childhood obesity and weight gain should be a priority in the prevention and treatment of SDB during this critical developmental period.

Obstructive sleep apnea and the metabolic syndrome: The road to clinically-meaningful phenotyping, improved prognosis, and personalized treatment

Obstructive sleep apnea (OSA) is an increasingly prevalent sleep disorder characterized by upper airway obstruction during sleep, resulting in breathing pauses, intermittent hypoxia, and fragmented sleep. In parallel, the constellation of adverse health outcomes associated with prolonged obesity, such as insulin resistance, elevated blood pressure, triglycerides, and reduced high-density lipoprotein cholesterol - termed metabolic syndrome -raises the risk of cardiovascular morbidity and mortality, type 2 diabetes, and all-cause mortality. Affecting 35-40% of U.S. adults, risk factors for metabolic syndrome, including obesity, middle age, sedentary behavior, and genetics, share considerable overlap with those for OSA. Thus, it has been difficult to disentangle cause, effect, and whether certain treatments, such as CPAP, can improve these outcomes. In this paper, we provide an update to our 2005 review which explored the association between OSA and metabolic syndrome, highlighting visceral obesity as the common etiological factor of both conditions. This update includes (a) recent data on physiological and biochemical mechanisms, (b) new data in nonobese men and women as well as children and adolescents, (c) insight from the latest treatment studies, (d) the role of aging in understanding clinically-meaningful phenotypes of the disorder, and (e) the potential diagnostic/prognostic utility of biomarkers in identifying OSA patients with the strongest cardiometabolic risk.

Prevalence of Obstructive Sleep Apnea in Children With Down Syndrome: A Meta-Analysis

STUDY OBJECTIVES

To estimate the prevalence of obstructive sleep apnea (OSA) in children with Down syndrome.

METHODS

Two authors independently searched databases, namely PubMed, MEDLINE, EMBASE, and the Cochrane Review database. The keywords used were "Down syndrome," "Trisomy 21," "OSA," "sleep apnea syndromes," "polysomnography" and "polygraphy." The prevalence of OSA based on apnea-hypopnea index (AHI) greater than 1, 1.5, 2, 5, and 10 event/h was estimated using a random-effects model. Subgroup analyses were conducted for children in different countries, sample size, study year, and risk of bias. Finally, the prevalence of OSA was compared between two types of sleep studies (polysomnography versus polygraphy).

RESULTS

A total of 18 studies (1,200 children) were included (mean age: 7.7 years; 56% boys; mean sample size: 67 patients). Five studies had low risk of bias, and nine and four studies had moderate and high risk of bias, respectively. The OSA was evaluated through polygraphy in 2 studies, and polysomnography in 16 studies. For children who underwent polysomnography, the prevalences of OSA based on AHI > 1, 1.5, 2, 5, and 10 events/h were 69%, 76%, 75%, 50%, and 34%, respectively. Subgroup analyses revealed no significant difference among all subgroups. Meta-regression showed that AHI > 5 events/h was inversely correlated with age (P < .001). Moreover, the prevalence of OSA based on AHI > 1.5 events/h was lower in polygraphy compared with polysomnography (59% versus 76%, P = .037).

CONCLUSIONS

OSA is highly prevalent in children with Down syndrome. Prevalence of moderate to severe OSA is higher in younger age.

Neurocognitive and behavioral functioning in adolescents with sleep-disordered breathing: a population-based, dual-energy X-ray absorptiometry study

BACKGROUND/OBJECTIVES

Sleep-disordered breathing (SDB) has been associated with neurocognitive and behavioral problems in young children; however, this association is less studied in adolescents. Evidence suggests that obesity plays a key role in the development of SDB, although its relative association with neurobehavioral functioning remains unclear. We examined whether SDB and obesity are associated with neurocognitive and behavioral problems in adolescents.

SUBJECTS/METHODS

A total of 421 adolescents (17.0±2.2y, 53.9% male) from the Penn State Child Cohort, a general population sample, underwent a 9-h polysomnography, clinical history, physical examination, neurocognitive evaluation and Dual-energy X-ray Absorptiometry (DXA) scan, and completed the Child or Adult Behavior Checklist. Obstructive sleep apnea (OSA) was defined as an apnea-hypopnea index (AHI)⩾2, primary snoring (PS) as AHI<2+snoring and no-SDB as AHI<2 without snoring. Body weight measures included body mass index (BMI) percentile, waist circumference (WC) and DXA-measured total adipose tissue (TAT).

RESULTS

WC and TAT were significantly associated with impaired vigilance, processing speed, working memory, and control interference and greater internalizing and externalizing behaviors, while BMI percentile was marginally associated. SDB per se (PS, AHI or OSA) was not significantly associated with impaired neurocognitive outcomes or greater behavioral problems. However, TAT was significantly associated with impaired vigilance and greater internalizing and externalizing behaviors and, to a lesser extent, slower processing speed and greater control interference, only in adolescents with OSA.

CONCLUSIONS

Central obesity, an etiopathogenic mechanism of OSA, is more strongly associated with neurocognitive and behavioral problems in adolescents than SDB alone. Deficits in low-order (vigilance) and high-order (executive) functions and behavioral problems observed in adolescents with OSA are primarily associated with increased central adiposity, a finding not entirely captured with less precise measures of obesity. These data support that OSA and its associated neurocognitive and behavioral morbidity are related to underlying metabolic dysfunction as early as adolescence.

Current child, but not maternal, snoring is bi-directionally related to adiposity and cardiometabolic risk markers: A cross-sectional and a prospective cohort analysis

PURPOSE

Obstructive sleep apnea (OSA), typically manifested as snoring, is closely associated with obesity. However, the directionality of associations of OSA with cardiometabolic risk markers is unclear, as obesity increases risk for OSA, and OSA results in excess weight gain and its metabolic consequences. Less is known about how obesity and OSA may relate in children and adolescents and whether maternal OSA may influence the development of obesity and cardiometabolic dysfunction in offspring.

BASIC PROCEDURES

Among 1078 children from the Project Viva cohort, we examined cross-sectionally and prospectively associations of parent-reported child or maternal snoring with cardiometabolic outcomes, including adiposity, adipokines, and insulin resistance.

MAIN FINDINGS

Cross-sectionally, child snoring was related to adiposity and metabolic risk, particularly body mass index (BMI; β 0.61kg/m2, 95% CI 0.33, 0.89; p<0.001), trunk fat mass index (β 0.23kg/m2, CI 0.12, 0.34; p<0.001), high-density lipoprotein cholesterol (β -1.47mg/dL, CI -2.69, -0.25; p=0.02), and metabolic risk z-score (β 0.08, CI 0.02, 0.14; p=0.01) after correction for covariates. Prospectively, adiposity (BMI, trunk fat, fat mass, and waist circumference) and cardiometabolic (leptin, HOMA-IR, CRP, and global metabolic risk) measures at mid-childhood (~7y) were associated with child snoring at the early teen visit (~12y) after correction for covariates. Child snoring at ~9y was related to changes in adiposity between mid-childhood and early teen visits.

CONCLUSIONS

Child but not maternal snoring, was related to child adiposity and cardiometabolic outcomes. Adiposity and child snoring are associated with each other cross-sectionally and are each predictive of the other among children/adolescents prospectively. These results suggest similar mechanisms in pediatric/adolescent populations as in adults for the development of sleep-disordered breathing and sleep apnea that will need to be confirmed in randomized clinical trials. Importantly, this research points to the need to target both sleep and obesity in order to break this vicious cycle.

Reviewing the relationship between OSA and cognition: Where do we go from here?

Obstructive sleep apnoea (OSA) is a disorder of breathing during sleep resulting in temporary reduction in cerebral oxygenation and sleep disruption. A growing body of research reveals a relatively consistent pattern of deficits in cognition, particularly in attention, episodic memory, and executive function, which are partially remediated by treatment. This is where the consensus ends. Despite a number of competing explanations regarding how OSA affects cognition, reliable evidence is hard to find, which may relate to the many, common conditions co-morbid with OSA or to the methodological challenges in this field. This paper reviews the evidence for cognitive impairment in OSA, the proposed models of cognitive harm, the impact of co-morbidities and the many methodological and theoretical challenges of exploring the effect of OSA on cognition. To overcome some of these challenges, we end by proposing a number of future directions for the field, including suggesting some core design elements for future studies.

Increased inflammation from childhood to adolescence predicts sleep apnea in boys: A preliminary study

While chronic systemic inflammation in obstructive sleep apnea (OSA) has been traditionally considered a consequence of intermittent hypoxia, several treatment studies targeting inflammation suggest that this process may precede the development of the disorder. A recent cross-sectional study in the Penn State Child Cohort (PSCC) revealed that inflammation largely mediates the association between visceral adiposity and OSA in adolescence. The purpose of this study was to examine for the first time whether, longitudinally, inflammation precedes OSA during this developmental period. A subsample of the PSCC with longitudinal sleep and inflammation data (n=51) was included in this study. Participants underwent 9-h polysomnography (22:00-7:00), physical exam, and fasting morning blood draw at both time points. Plasma C-reactive protein (CRP) was measured via ELISA. At follow-up, visceral, subcutaneous, and total fat area were assessed via dual X-ray absorptiometry. Sex differences in body composition emerged in adolescence, with boys having more visceral adiposity than girls. Longitudinal increases in waist circumference from childhood to adolescence were associated with increases in CRP (ΔCRP) and follow-up CRP in boys, but not girls. Furthermore, in boys, ΔCRP was associated with higher follow-up apnea/hypopnea index (AHI). When ΔCRP was entered into a model predicting follow-up AHI, Δwaist circumference was no longer significant, indicating that inflammation largely explains the association between increasing central obesity and OSA severity. These preliminary findings, in a longitudinal, non-clinical sample of children developing OSA, suggest that inflammation derived from visceral adipose tissue precedes the development of the disorder, suggesting a potential causal mechanism.

Longitudinal Cardiovascular Outcomes of Sleep Disordered Breathing in Children: A Meta-Analysis and Systematic Review

Objectives

The presence of sleep disordered breathing (SDB) is known to impact long-term cardiovascular morbidity in adults; however, the long-term effects in children are poorly understood. We aimed to systematically review and synthesize studies published to date on the long-term effects of SDB in children.

Study Design

Meta-analysis and systematic review using PubMed, CINAHL, Embase, and Scopus (all indexed years).

Methods

We searched for English-language articles containing original human data from prospective studies, with ≥7 participants, in children ≤18 years of age. Data regarding study design, demographics, clinical characteristics, outcomes, level of evidence, and risk of bias were obtained. Articles were independently reviewed by three investigators. Retrospective and cross-sectional studies were excluded.

Results

Of 1701 identified abstracts, 25 articles (combined n = 1418) were ultimately included. All studies reported longitudinal outcomes following treatment of SDB, 21 studies exclusively reporting outcomes after adenotonsillectomy. Therefore, studies were combined to objectively assess the effect of SDB treatment on cardiovascular outcomes. Although all cardiovascular parameters were within the normal range at baseline, at follow-up there was a significant decrease in mean pulmonary artery pressure, right ventricular end diastolic diameter, heart rate, mitral Em/Am ratio, and C-reactive protein. There was no significant change in interventricular septum thickness, left ventricular parameters (shortening fraction, systolic and end diastolic diameters, ejection fraction, posterior wall thickness, isovolumetric relaxation time), left atrial diameter, and aortic and pulmonary valve peak velocities.

Conclusions

Studies assessing the long-term cardiovascular effects of SDB in children are limited. The available literature indicates effects on autonomic function, right, and left heart function following treatment for SDB. However, well-designed, large-scale, prospective cohort studies (using standardized outcomes) are needed to better understand the relationship of cardiovascular morbidity in the context of pediatric SDB.

Frequency of snoring, rather than apnea-hypopnea index, predicts both cognitive and behavioral problems in young children

OBJECTIVE

Primary snoring (PS) and obstructive sleep apnea (OSA) not only affect the quality of sleep in a large number of young children, but have also been repeatedly associated with a variety of behavioral and cognitive problems. However, little is known about the potentially differing relationships of behavioral and cognitive pathology within the sleep disordered breathing (SDB) spectrum.

METHOD

This study examined data from an enriched for snoring community sample of 631 children aged between 4 and 10 years. Multivariate mixed models were used to assess the relationship between both snoring and the apnea-hypopnea index (AHI). Numerous cognitive and behavioral variables were used, while adjusting for several important demographic variables. These were followed by univariate analyses of individual measures and sensitivity analyses.

RESULTS

Results indicated that snoring status is a significant predictor of general behavioral (p = 0.008) and cognitive (p = 0.013) domains, even after adjusting for baseline covariates and AHI severity. More frequent snoring was associated with poorer outcomes independent of AHI. However, AHI did not emerge as a significant predictor of the overall cognitive functioning domain (p = 0.377). Additionally, although AHI was a significant predictor of the general behavioral functioning domain (p = 0.008), the significance pattern and nature of its relationship with individual behavioral measures were inconsistent in post-hoc analyses.

CONCLUSION

The findings of this study suggest that general behavioral and cognitive function may decline with greater snoring severity. Further, snoring should not simply be assumed to represent a lower severity level of SDB, but should be examined as a potential predictor of relevant outcomes.

When and why to treat the child who snores?

Obstructive sleep-disordered breathing (SDB) can result in cardiovascular and neurocognitive morbidity as well as adversely affect behavior, growth, quality of life, and nocturnal continence. This article summarizes the latest evidence regarding the morbidity related to obstructive SDB, commenting on the impact of severity of obstruction, that is, the difference in effects seen of moderate to severe obstructive sleep apnea syndrome (OSAS) compared to those of mild OSAS or primary snoring. The impact of therapy is discussed, focusing on which children are likely to benefit from treatment interventions; namely those with moderate or severe OSAS irrespective of the presence of morbidity, children with mild OSAS with associated morbidity or predictors of SDB persistence such as obesity, and children with complex conditions accompanied by upper airway obstruction like craniosynostosis and Prader-Willi syndrome. The co-existing conditions which may improve when treatment for obstructive SDB is offered are reviewed, while the clinical parameters associated with spontaneous improvement or resolution of obstructive SDB are discussed. The intention being to enable clinicians to make informed decisions on who should be treated, when and why. Pediatr Pulmonol. 2017;52:399-412. © 2016 Wiley Periodicals, Inc.

Insomnia symptoms with objective short sleep duration are associated with systemic inflammation in adolescents

Inflammation has been suggested as a potential pathway by which insomnia and short sleep can affect risk of morbidity in adults. However, few studies have examined the association of insomnia with inflammation in adolescents, despite accumulating evidence that pathophysiologic changes may already occur during this critical developmental period. The present study sought to examine the association of insomnia symptoms with systemic inflammation and the role of objective sleep duration in this association. Participants were 378 adolescents (16.9±2.3y, 45.8% female) from the Penn State Child Cohort, a population-based sample who underwent 9-h polysomnography (PSG) followed by a single fasting blood draw to assess plasma levels of C-reactive protein (CRP) and other inflammatory markers. Insomnia symptoms were defined by a self-report of difficulties falling and/or staying asleep, while objective sleep duration groups were defined as a PSG total sleep time ⩾8, 8-7, and ⩽7h. We assessed the association of insomnia symptoms, objective sleep duration, and their interaction with inflammatory markers, while adjusting for multiple potential confounders. Adolescents reporting insomnia symptoms had significantly higher levels of CRP compared to controls and a significant interaction (p<0.01) showed that objective sleep duration modified this association. Elevated CRP was present in adolescents with insomnia symptoms and ⩽7h of sleep (1.79mg/L) as compared to controls or adolescents with insomnia symptoms and ⩾8h of sleep (0.90mg/L and 0.98mg/L, respectively) or controls with ⩽7h of sleep (0.74mg/L; all p-values <0.01). In sum, insomnia symptoms with objective short sleep duration are associated with systemic inflammation as early as adolescence. This study suggests that chronic low-grade inflammation may be a common final pathway towards morbidity in adulthood in this insomnia phenotype.

The insomnia with short sleep duration phenotype: an update on it's importance for health and prevention

PURPOSE OF REVIEW

It was first proposed in the late 1990s that objective markers of sleep disturbance could serve as an index of the biological severity of insomnia. In 2013, a heuristic model of two insomnia phenotypes based on objective sleep duration was proposed. Herein, we review the studies conducted in the past 3 years on the insomnia with short sleep duration phenotype and its implications for a clinical research agenda.

RECENT FINDINGS

Studies have shown that insomnia with objective short sleep duration is associated with physiologic hyperarousal and cardiometabolic and neurocognitive morbidity, whereas insomnia with normal sleep duration is not. Both insomnia phenotypes are associated with psychiatric morbidity albeit through different psychobiological mechanisms. Novel recent studies have included occupational outcomes, developmental approaches, at-home objective sleep testing, diagnostic accuracy measures, and response to cognitive-behavioral treatment.

SUMMARY

Accumulating evidence in the past years has continued to support that insomnia with short sleep duration is a more severe phenotype of the disorder associated with physiologic changes, significant morbidity and mortality and, potentially, a differential response to treatment.

Insomnia Phenotypes Based on Objective Sleep Duration in Adolescents: Depression Risk and Differential Behavioral Profiles

Based on previous studies on the role of objective sleep duration in predicting morbidity in individuals with insomnia, we examined the role of objective sleep duration in differentiating behavioral profiles in adolescents with insomnia symptoms. Adolescents from the Penn State Child Cohort (n = 397, ages 12–23, 54.7% male) underwent a nine-hour polysomnography (PSG), clinical history, physical examination and psychometric testing, including the Child or Adult Behavior Checklist and Pediatric Behavior Scale. Insomnia symptoms were defined as a self-report of difficulty falling and/or staying asleep and objective “short” sleep duration as a PSG total sleep time ≤7 h. A significant interaction showed that objective short sleep duration modified the association of insomnia symptoms with internalizing problems. Consistently, adolescents with insomnia symptoms and short sleep duration were characterized by depression, rumination, mood dysregulation and social isolation, while adolescents with insomnia symptoms and normal sleep duration were characterized by rule-breaking and aggressive behaviors and, to a lesser extent, rumination. These findings indicate that objective sleep duration is useful in differentiating behavioral profiles among adolescents with insomnia symptoms. The insomnia with objective short sleep duration phenotype is associated with an increased risk of depression earlier in the lifespan than previously believed.

Inflammation mediates the association between visceral adiposity and obstructive sleep apnea in adolescents

Only a handful of studies, primarily in clinical samples, have reported an association between obesity, inflammation, and obstructive sleep apnea (OSA) in children and adolescents. No studies, however, have examined the pathogenetic link between visceral adiposity, systemic inflammation, and incident OSA in a large general population sample using objective measures of sleep and body fat. Adolescents (n = 392; mean age 17.0 ± 2.2 yr, 54.0% male) from the Penn State Child Cohort (PSCC) underwent 9-h overnight polysomnography; a DXA scan to assess body fat distribution; and a single fasting blood draw for the assessment of plasma interleukin-6 (IL-6), IL-6 soluble receptor (IL-6 sR), tumor necrosis factor alpha (TNFα), tumor necrosis factor receptor 1A (TNFR1), C-reactive protein (CRP), leptin, and adiponectin levels via ELISA. Visceral fat area was significantly elevated in moderate OSA (AHI ≥ 5), especially in boys. IL-6, CRP, and leptin were highest in adolescents with moderate OSA, even after adjusting for BMI percentile. Mediation analysis revealed that 42% of the association between visceral fat and OSA in adolescents was mediated by IL-6 (p = 0.03), while 82% of the association was mediated by CRP (p = 0.01). These data are consistent with the model of a feed-forward, vicious cycle, in which the release of proinflammatory cytokines by visceral adipocytes largely explains the association between central obesity and OSA; in turn, inflammation is also elevated in OSA independent of BMI. These findings, in a large, representative, non-clinical sample of young people, add to our understanding of the developmental pathogenesis of sleep apnea.

Insomnia, Health-Related Quality of Life and Health Outcomes in Children: A Seven Year Longitudinal Cohort

Insomnia is common in children, and is associated with decreased school performance and increased psychopathology. Although adult insomnia is linked to worsened health-related quality of life (HRQOL), there is insufficient data evaluating insomnia and HRQOL in children. We examined the HRQOL and health associations of insomnia in a longitudinal cohort of 194 children (96 girls, age at study start 8.7 ± 1.6 years, age at data analysis 15.0 ± 1.8 years) over 7 years. International Classification of Sleep Disorders, second edition (ICSD2) derived insomnia was seen intermittently in 27% of children, and was persistent in 4%. Children reporting ICSD2-derived insomnia had lower HRQOL. Additionally, the presence of insomnia was associated with an increased risk of reporting a new medical condition (intermittent insomnia odds ratio 5.9 [95% CI 1.3–26.7, p = 0.04], persistent insomnia odds ratio 8 [95% CI 2.3–27.7, p = 0.001]). Persistent ICSD2-derived insomnia was associated with an increased risk of reporting a new medication (odds ratio 4.9 (95% CI 1.0–23.6), p = 0.049), and reporting a new psychiatric medication (odds ratio 13.7, 95% CI: 2.6–73.5, p = 0.002). These associations were present even after adjusting for socioeconomic factors and the presence of obstructive sleep apnea. Insomnia in children is associated with worsened HRQOL and health outcomes.