The Relationship Between Sleep-Disordered Breathing Severity and Daytime Adaptive Functioning in Children with Down Syndrome

The surge in heart rate and blood pressure at respiratory event termination is dampened in children with down syndrome

BACKGROUND

Children with Down syndrome (DS) have a high prevalence of sleep disordered breathing (SDB) and altered cardiovascular autonomic control. We aimed to analyze the effect of DS on the surge in heart rate (HR) and pulse transit time (PTT, an inverse surrogate measure of blood pressure change) at respiratory event termination.

METHODS

44 children (3-19 y) with DS and 44 typically developing (TD) children matched for SDB severity, age and sex underwent overnight polysomnography. Multilevel modelling determined the effect of DS on HR and PTT changes between a 10s pre-event to the latter half of each respiratory event (late-event) and 15s post-event during NREM and REM, accounting for SDB severity and event length.

RESULTS

The children with DS had a significantly smaller % change in HR late-event to post-event (NREM: DS 26.4 % ± 17.5 % (mean ± SD), TD 30.7 % ± 21.0 %; REM DS 16.9 % ± 15.3 %, TD 21.0 % ± 14.0 %; p < 0.05 for both) compared with TD children for obstructive events, and central events (13.2 % ± 17.0 %, TD 18.8 % ± 17.0 %; p < 0.01) during REM. %change in PTT was significantly smaller in the DS group during NREM and REM from pre-event and late-event to post-event compared with TD children for obstructive and central events.

CONCLUSION

These results suggest children with DS have dampened HR and BP responses to respiratory events compared with TD children. Whether this is symptomatic of autonomic dysfunction or a protective factor for the cardiovascular system in children with DS remains to be elucidated.

OSA type-III and neurocognitive function

Obstructive sleep apnea (OSA) due to a hypertrophy of the adenoids and/or the tonsils in otherwise healthy children is associated with neurocognitive dysfunction and behavioural disorders with various degrees of hyperactivity, aggressiveness, sometimes evolving to a label of attention-deficit hyperactivity disorder. Children with anatomical and/or functional abnormalities of the upper airways represent a very specific population which is at high risk of OSA (also called complex OSA or OSA type III). Surprisingly, the neurocognitive consequences of OSA have been poorly studied in these children, despite the fact that OSA is more common and more severe than in their healthy counterparts. This may be explained by that fact that screening for OSA and sleep-disordered breathing is not systematically performed, the performance of sleep studies and neurocognitive tests may be challenging, and the respective role of the underlining disease, OSA, but also poor sleep quality, is complex. However, the few studies that have been performed in these children, and mainly children with Down syndrome, tend to show that OSA, but even more disruption of sleep architecture and poor sleep quality, aggravate the neurocognitive impairment and abnormal behaviour in these patients, underlining the need for a systematic and early in life assessment of sleep and neurocognitive function and behaviour in children with OSA type III.

Effect of sleep disordered breathing severity in children with Down syndrome on parental wellbeing and social support

INTRODUCTION

Sleep disorders, particularly sleep disordered breathing (SDB), are common in children with Down syndrome (DS). We investigated the relationship between SDB severity and parental psychological wellbeing and their perception of social support.

METHODS

44 children with DS (3-19 years) underwent overnight polysomnography and were categorised into three groups: primary snoring, Mild and Moderate/Severe obstructive sleep apnoea (OSA). Parents completed questionnaires about their child's behaviour (Child Behavior Checklist), sleep symptoms (Pediatric Sleep Survey Instrument) and SDB-related quality of life (OSA-18), together with the DUKE-UNC Functional Social Support (DUKE) and Psychological General Well-Being Index (PGWBI) questionnaires for themselves. 34 children completed a follow-up study after 2 years.

RESULTS

There were no significant differences between SDB severity groups for parental perceived social support or psychological wellbeing. Total scores on the DUKE were below average and PGWBI scores were indicative of moderate psychological distress in all three groups. Reduced perceived levels of social support were significantly correlated with externalising child behaviour and sleep disturbance. Diminished parental psychological wellbeing was also significantly correlated with increased sleep disturbances and reduced quality of life in children. At follow-up there were no significant changes in any questionnaire outcome, however parents of children with improved SDB severity had improved PGWBI vitality scores.

CONCLUSION

The degree of parent-reported sleep disturbance in children with DS was linked to suboptimal perceived parental social support and poor psychological wellbeing. Our results emphasise the need for enhanced awareness of the detrimental effects of sleep problems in children with DS on parental wellbeing.

Prediction of obstructive sleep apnoea in children and adolescents with Down syndrome

BACKGROUND

Obstructive sleep apnoea (OSA) is common in children and adolescents with Down syndrome (DS). Clinical guidelines recommend that all children with DS have polysomnography (PSG) for assessment of OSA by the age of 4 years, but access is limited and testing may be burdensome for children and families.

METHODS

The purpose of this prospective cross-sectional cohort study was to identify a model to predict OSA in this group that could be tested in an external population to triage children and adolescents with DS for PSG. These models were based on a comprehensive set of potential predictive demographic, anthropometric, quality of life and sleep-related variables.

RESULTS

The results of this study show the predictive power of a model based on the sleep disordered breathing subscale of the Pediatric Sleep Survey Instrument and sleep fragmentation quantified using actigraphy in determining moderate-severe OSA in children and adolescents with DS. This model exhibits high sensitivity (82%), specificity (80%), positive predictive value (75%) and negative predictive value (86%).

CONCLUSIONS

We demonstrate the utility of a tool containing the sleep disordered breathing subscale of the Pediatric Sleep Survey Instrument and sleep fragmentation quantified using actigraphy in identifying children and adolescents with DS who have moderate/severe OSA.

Sleep disordered breathing improvement prevents worsening of autonomic dysfunction in children with Down syndrome

BACKGROUND

Resolution of sleep disordered breathing (SDB) in typically developing children normalises heart rate variability (HRV), a measure of autonomic control, to that of non-snoring controls. Children with Down Syndrome (DS) have dampened heart rate variability (HRV) but the effect of treatment is not known. To assess the effect of improvement of SDB on autonomic control we compared HRV in children with DS whose SDB improved over 2 y, to those whose SDB did not improve.

METHODS

24 children (3-19 y) had a baseline and follow-up polysomnographic study 2 y later. Improved SDB was defined as a reduction in obstructive apnea hypopnea index (OAHI) to ≤ 50% of baseline. Children were grouped into Improved (n = 12) and Unimproved (n = 12). Power spectral analysis of the ECG determined low frequency (LF), high frequency (HF) power and the LF/HF ratio. Seven children in the Improved and 2 in the Unimproved group were treated following the baseline study.

RESULTS

In the Unimproved group at follow-up, LF power was lower compared to baseline during N3 and Total Sleep (p < 0.05 for both). HF power was lower during REM (p < 0.05). HRV remained unchanged between studies in the Improved group.

CONCLUSION

Autonomic control worsened as indicated by lower LF and HF power in children whose SDB was not improved. In contrast, in those children with improved SDB, autonomic control remained the same, suggesting improvement in SDB severity prevents further worsening of autonomic control in children with DS.

Effects of Treatment of Sleep Disordered Breathing on Sleep Macro- and Micro-Architecture in Children with Down Syndrome

Background: Children with Down syndrome (DS) are at increased risk of obstructive sleep disordered breathing (SDB), which is associated with intermittent hypoxia and sleep disruption affecting daytime functioning. We aimed to examine the effects of treatment of SDB on sleep quality and daytime functioning in children with DS. Methods: Children with DS and SDB (n = 24) completed a baseline and follow-up overnight polysomnographic (PSG) study 22 ± 7 months (mean ± SD) later. Sleep micro-architecture was assessed using EEG spectral analysis, and parents completed a number of questionnaires assessing sleep, behavior, daytime functioning, and quality of life (QOL). Results: A total of nine children (38%) were treated. At baseline, the treated group had more severe SDB compared to the untreated group. SDB severity was significantly improved from 40.3 ± 46.9 events/h to 17.9 ± 26.9 events/h (p < 0.01) at follow up in children who were treated. There were no significant differences in sleep macro-architecture parameters from baseline to follow up in either the treated or untreated group. Sleep micro-architecture was not different between studies in the treated group, however this tended to improve in the untreated group, particularly in REM sleep. Daytime functioning and behavior were not different between the studies in either group, however, QOL improved after treatment. Conclusions: Our study identified that treatment of SDB improves severity of the disease as defined by PSG, and this was associated with parental reports of improved QOL, despite treatment having no demonstrable impacts on sleep quality, behavior, or daytime functioning.

Circadian Sleep-Activity Rhythm across Ages in Down Syndrome

Across all ages, individuals with Down syndrome (DS) experience high rates of sleep problems as well as cognitive impairments. This study sought to investigate whether circadian rhythm disruption was also experienced by people with DS and whether this kind of sleep disorder may be correlated with cognitive performance. A cross-sectional study of 101 participants (58 with DS, 43 with typical development) included individuals in middle childhood (6–10 years old), adolescence (11–18 years old), and young adulthood (19–26 years old). Sleep and markers of circadian timing and robustness were calculated using actigraphy. Cognitive and behavioral data were gathered via a novel touchscreen battery (A-MAP^TM, Arizona Memory Assessment for Preschoolers and Special Populations) and parent questionnaire. Results indicated that children and adolescents with DS slept the same amount as peers with typical development, but significant group differences were seen in phase timing. The circadian robustness markers, interdaily stability and intradaily variability of sleep-wake rhythms, were healthiest for children regardless of diagnostic group and worst for adults with DS. Amplitude of the 24-h activity profile was elevated for all individuals with DS. In analyses of the correlations between sleep quality, rhythms, and cognition in people with DS, interdaily stability was positively correlated with reaction time and negatively correlated with verbal and scene recall, a finding that indicates increased stability may paradoxically correlate with poorer cognitive outcomes. Further, we found no relations with sleep efficiency previously found in preschool and adult samples. Therefore, the current findings suggest that a thorough examination of sleep disorders in DS must take into account age as well as circadian robustness to better understand sleep-cognitive correlations in this group.

Children with Down syndrome and sleep disordered breathing have altered cardiovascular control

BACKGROUND

Sleep disordered breathing (SDB) in typically developing (TD) children is associated with adverse cardiovascular effects. As children with Down syndrome (DS) are at increased risk for SDB, we aimed to compare the cardiovascular effects of SDB in children with DS to those of TD children with and without SDB.

METHODS

Forty-four children with DS (3-19 years) were age and sex matched with 44 TD children without SDB (TD-) and with 44 TD children with matched severity of SDB (TD+). Power spectral density was calculated from ECG recordings, for low frequency (LF), high frequency (HF), total power and the LF/HF ratio.

RESULTS

Children with DS had lower HF power, and higher LF/HF during sleep and when awake. There were no differences between groups for LF power. SpO₂ nadir, average SpO₂ drop and SpO₂ > 4% drop were larger in the DS group compared to the TD+ group (p < 0.05 for all).

CONCLUSIONS

Our findings demonstrate significantly reduced parasympathetic activity (reduced HF power) and increased LF/HF (a measure of sympathovagal balance) in children with DS, together with greater exposure to hypoxia, suggesting SDB has a greater effect in these children that may contribute to an increased risk of adverse cardiovascular outcomes.

IMPACT

Sleep disordered breathing in children with Down syndrome exacerbates impaired autonomic control and increases exposure to hypoxia, compared to typically developing children. In typically developing children sleep disordered breathing has adverse effects on autonomic cardiovascular control. The prevalence of sleep disordered breathing is very high in children with Down syndrome; however, studies on the effects on cardiovascular control are limited in this population. This study supports screening and early treatment of sleep disordered breathing in children with Down syndrome.

Child Sleep Linked to Child and Family Functioning in Children with Down Syndrome

Sleep problems have a bi-directional impact on the daytime performance of children, parental well-being, and overall family functioning in the general population. Children with Down syndrome (DS) are at a high risk of sleep problems, yet the relationship between sleep problems, adaptive functioning, and family stress in children with DS is not well documented. We examined the relationship between sleep (i.e., duration and quality) and child and parent/family functioning. Sixty-six children with DS wore an actigraph for a week to assess their sleep duration and sleep efficiency. Their parents completed ratings on child sleep duration and parasomnias, child adaptive functioning, parental depression and sleep, and family stress. The parents' reports of their children's sleep duration were associated with parental depressive symptoms. The parents' reports of their children's restless sleep behaviors were associated with poorer performances in child-compliant/calm behaviors, worse parental sleep, and negative parental feelings and sibling relationships. The findings from actigraph measures of the children's sleep demonstrated that greater sleep efficiency was associated with greater child adaptive functioning and fewer parental depressive symptoms. The study findings provide preliminary evidence that sleep problems are related to child adaptive functioning, parental functioning, and family stress in children with DS.

The impact of sleep problems on functional and cognitive outcomes in children with Down syndrome: a review of the literature

STUDY OBJECTIVES

The aim of this review was to summarize the existing literature on the association between sleep problems and cognition, function, and behavior in children with Down syndrome.

METHODS

Embase, PubMed, CINAHL, and PsychINFO databases were searched to retrieve all studies published between 1990 and 2018 that evaluated the relationship between sleep and cognition, function, or behavior in children with Down syndrome.

RESULTS

Fifteen articles were included, which were mostly of a cohort or case-controlled design. Five articles addressed sleep and cognition only, 6 reported on sleep and behavior, and only 1 reported on sleep and functional ability. Three papers evaluated sleep and both cognition and behavior. Findings varied across studies with methodological differences, making it difficult to directly compare results. The association between sleep and behavior or cognition in children with Down syndrome remains uncertain, but a large study in 110 children provides strong evidence of a negative impact of sleep disorders on the accomplishment of daily life habits.

CONCLUSIONS

The impact of coexisting sleep disorders in children with Down syndrome has not been widely studied, with only 15 relevant studies found through an extensive literature review. Large well-designed studies are required to fully understand this relationship further. This is important as sleep-disordered breathing and difficulties with sleep patterns and routines are highly prevalent in children with Down syndrome. Sleep may be one of the few treatable factors that can assist in improving long-term outcomes in this population.

Characterization of Sleep Disturbances in Children and Adolescents with Down Syndrome and Their Relation with Cognitive and Behavioral Features

Despite sleep disturbances are common among youths with Down syndrome (DS), the cognitive and behavioral features associated with sleep problems have not yet been studied extensively. The present study investigated the presence of sleep disturbances in a group of children and adolescents with DS and their cognitive and behavioral correlates. Seventy-one children and adolescents with DS underwent a neuropsychological evaluation, whereas parents completed questionnaires for the screening of the child's sleep, emotional and behavioral problems. We found no association between sleep disturbances and sex, nonverbal IQ, nor adaptive abilities. However, we found that age was positively associated with disorders in initiating and maintaining sleep (DIMS) and disorders of excessive somnolence (DOES), while body mass index was related with DOES. We also detected a relationship between visual-motor integrations and DIMS, as well as multiple associations between sleep disturbances and psychopathological and behavioral problems, mainly externalizing symptoms. The present study provided a detailed characterization of sleep problems in relation to several features of youths with DS. The proper identification of sleep disturbances profile in the DS population could support the process of clinical evaluation, in particular for psychopathological aspects.

Opportunities, barriers, and recommendations in down syndrome research

BACKGROUND

Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

OBJECTIVE

The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan.

METHODS

NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS.

RESULTS

This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade.

CONCLUSIONS

This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy.

Consequences of paediatric sleep disordered breathing: contributions from Australian and New Zealand investigators

AIMS

To highlight the contributions of Australian and New Zealand researchers to the identification of the consequences of paediatric sleep disordered breathing (SDB).

METHODS

A search was conducted in PubMed using the terms "sleep disordered breathing" "child" and "Australia or New Zealand". All abstracts were reviewed and those which focused on the consequences of SDB have been included.

RESULTS

Australasian research into the consequences of SDB has grown exponentially over the last 35 years. SDB has significant adverse consequences for quality of life, behaviour, neurocognition and the cardiovascular system and the Australasian research studies investigating these are summarised.

CONCLUSIONS

Australian and New Zealand researchers have played a significant role in understanding the consequences of paediatric SDB and the mechanisms which underpin these. The research conducted "Downunder" has led the world in this field of research and will continue to provide evidence to improve the lives of children not only in Australasia but around the world.

Sleep problems in adults with Down syndrome and their family carers

BACKGROUND

Sleep disturbance is common and can have harmful psychological and physical effects. While sleep problems in children with Down syndrome (DS) have received a reasonable amount of attention, very little has been written about this topic in adults with DS.

METHOD

The present study consisted of an online survey completed by 100 family carers of adults with DS.

RESULTS

High rates of sleep problems of different types were reported in the adults with DS comparable to those found in children with DS in previous research. Significant associations were found between sleep problems and body mass index, excessive daytime sleepiness and a range of health and psychological problems. Low rates of treatments for sleep problems were reported. The majority of family caregivers felt their own sleep was affected.

CONCLUSIONS

Sleep problems in adults with DS are common and varied. Assessment and treatment of such problems are likely to improve quality of life.

Sleep and sleep disordered breathing in children with down syndrome: Effects on behaviour, neurocognition and the cardiovascular system

Down syndrome (DS), the most common human chromosomal malformation, has an estimated annual incidence of one in 1000 live births worldwide. Sleep problems are common in children with DS, reported by parents in up to 65% of school-aged children, significantly higher rates than in typically developing (TD) children. Problems include difficulty in sleep initiation and maintenance together with obstructive sleep apnoea (OSA) which affects up to over 90%, of DS children compared with 1-5% in the general paediatric population. Any sleep problem has the potential to exert significant negative effects on daytime behaviour, learning and quality of life in TD children and there is now a growing body of evidence that children with DS are similarly affected. In addition to adverse effects on daytime functioning, OSA has adverse effects on the cardiovascular system and this is a particularly significant issue given the high rates of hypertension and premature cardiac disease in people with DS. This review discusses the effects of sleep problems and OSA on daytime functioning and cardiovascular function in children with DS and evidence of the effectiveness of treatment in improving outcomes and quality of life for these children.