Blood pressure in sleep disordered breathing

Effectiveness of Intranasal Mometasone Furoate vs Saline for Sleep-Disordered Breathing in Children: A Randomized Clinical Trial

Importance

Obstructive sleep-disordered breathing (SDB) in children is characterized by snoring and difficulty breathing during sleep. SDB affects at least 12% of otherwise healthy children and is associated with significant morbidity. Evidence from small clinical trials suggests that intranasal corticosteroids improve SDB as measured by polysomnography; however, the effect on symptoms and quality of life is unclear.

Objective

To determine whether intranasal mometasone furoate is more effective than intranasal saline for improving symptoms and quality of life in children with SDB.

Design, Setting, and Participants

The MIST trial was a multicenter, randomized, double-blind, placebo-controlled trial, recruiting participants from June 8, 2018, to February 13, 2020. Children aged 3 to 12 years who were referred to a specialist for significant SDB symptoms were included; exclusions were previous adenotonsillectomy, body mass index greater than the 97th percentile, and severe SDB. Randomization was stratified by site, and data were analyzed on an intention-to-treat basis from October 28, 2020, to September 25, 2022.

Interventions

Participants were randomly assigned to receive mometasone furoate, 50 μg, or sodium chloride (saline), 0.9%, 1 spray per nostril daily, dispensed in identical bottles.

Main Outcomes and Measures

The primary outcome was resolution of significant SDB symptoms (ie, reduction to a level no longer requiring referral to a specialist as per the American Academy of Pediatrics guidelines) at 6 weeks, measured by parental report of symptoms using the SDB Score.

Results

A total of 276 participants (mean [SD] age, 6.1 [2.3] years; 146 male individuals [53%]) were recruited, 138 in each treatment arm. Resolution of significant SDB symptoms occurred in 56 of 127 participants (44%) in the mometasone group and 50 of 123 participants (41%) in the saline group (risk difference, 4%; 95% CI, -8% to 16%; P = .51) with 26 participants lost to follow-up and missing values managed by multiple imputation. The main adverse effects were epistaxis, affecting 12 of 124 participants (9.7%) in the mometasone group and 18 of 120 participants (15%) in the saline group, and nasal itch/irritation, affecting 12 of 124 participants (9.7%) in the mometasone group and 22 of 120 participants (18%) in the saline group.

Conclusions and Relevance

Results of this randomized clinical trial suggest that there was no difference in treatment effect between intranasal mometasone and saline for the management of SDB symptoms. The results suggest that almost one-half of children with SDB could be initially managed in the primary care setting and may not require referral to specialist services, as is currently recommended.

Trial Registration

Australian New Zealand Clinical Trials Registry: ANZCTRN12618000448246.

Feasibility and efficacy of active remote monitoring of home ventilation in pediatrics

BACKGROUND

Non-invasive positive airway pressure (PAP) therapy is used to treat children with sleep-disordered breathing. Effective management requires good adherence. In response to the problem of reduced adherence over time, a pilot study using ventilators equipped with technology to remotely monitor home adherence was undertaken.

METHODS

From July 2019, children requiring PAP therapy consented for remote monitoring. Data collected included ventilator usage, apnea-hypopnea index (AHI), and mask leak. Parents were contacted on Days 14, 42, and 90 post-establishment. A proforma was used to assess parental understanding and ways to improve therapy adherence. A parental feedback questionnaire was completed on Day 90 of the study.

RESULTS

Median nightly PAP usage over 90-day post-establishment was 6.58 h (interquartile range: 2.47-8.62); 60% of patients met criteria for good adherence (>4 h for >70% of nights). There was a decrease in median nightly usage in Week 1 (6.92 h) versus Week 12 (6.15 h), p =  0.04. Mask leak was higher in Week 1 (17.7 L/min) versus Week 12 (14.7 L/min), p =  0.053. There was no significant difference in AHI between Week 1 (2.7/h) versus Week 12 (2.3/h), p =  0.75. 45% of questionnaire respondents felt active remote monitoring positively influenced PAP usage, whilst 84% reported overall satisfaction with PAP therapy.

CONCLUSIONS

Remote monitoring technology has the potential to guide adjustments in PAP therapy, monitor and improve adherence in children, and reduce the burden of hospital-based review. Preliminary work shows high approval from parents.

TNF-α promotes insulin resistance in obstructive sleep apnea-hypopnea syndrome

Obstructive sleep apnea hypopnea syndrome (OSAHS) is the most serious among children with sleep disordered breathing. The present study aimed to investigate whether TNF-α could decrease the glucose transporter type 4 insulin-responsive (GLUT-4) expression to promote insulin resistance through the TNF-α/IKKβ/IKβ/NF-κB signaling pathway in OSAHS. In total, 30 obese children with OSAHS and 30 non-OSAHS obese children were enrolled into the present study. TNF-α expression in adenoid tissues was detected by western blot analysis and immunohistochemistry. The expression of inflammatory factors (IL-1β, IL-6 and IFN-γ) and TNF-α/IKKβ/IKβ/NF-κB signaling pathway-associated proteins was also detected by western blot analysis. The expression of insulin resistance-associated factors, insulin receptor substrate 1 (IRS1) and GLUT4, was determined by western blot analysis and immunohistochemistry. TNF-α expression was increased in adenoid tissues of children with OSAHS, which was also confirmed by immunohistochemistry. The expression levels of IL-1β, IL-6 and IFN-γ were all upregulated in adenoid tissues of children with OSAHS. The expression of IRS1 and GLUT4 was decreased in adenoid tissues of obese children with OSAHS and the result of immunohistochemistry was consistent with the result of western blot analysis. The protein level of TNF-α, and ratio of phosphorylated (p-)/total (t)-IKKβ, p/t-IKβ and p/t-NF-κB was increased in adenoid tissues of children with OSAHS. TNF-α could suppress the GLUT4 expression to promote insulin resistance by TNF-α/IKKβ/IKβ/NF-κB signaling pathway in OSAHS.

Short-term exposure to intermittent hypoxia leads to changes in gene expression seen in chronic pulmonary disease

Obstructive sleep apnea (OSA) results from episodes of airway collapse and intermittent hypoxia (IH) and is associated with a host of health complications. Although the lung is the first organ to sense changes in oxygen levels, little is known about the consequences of IH to the lung hypoxia-inducible factor-responsive pathways. We hypothesized that exposure to IH would lead to cell-specific up- and downregulation of diverse expression pathways. We identified changes in circadian and immune pathways in lungs from mice exposed to IH. Among all cell types, endothelial cells showed the most prominent transcriptional changes. Upregulated genes in myofibroblast cells were enriched for genes associated with pulmonary hypertension and included targets of several drugs currently used to treat chronic pulmonary diseases. A better understanding of the pathophysiologic mechanisms underlying diseases associated with OSA could improve our therapeutic approaches, directing therapies to the most relevant cells and molecular pathways.

Adherence to Sleep Therapies in Children and Adolescents

Improved recognition of obstructive sleep apnea (OSA) in children has led many to identify effective strategies to treat pediatric OSA. Positive airway pressure (PAP) therapy in children, which has been shown to resolve OSA, is highly contingent on adequate adherence. In pediatrics, adherence is complex, related largely to the influence of age. Consequently, reported adherence rates in children are often lower than adults. Notwithstanding, studies have identified significant risk factors, some modifiable, and several intervention strategies that may improve pediatric adherence. Close follow-up, including use of cloud-based monitoring, of children using PAP therapy may optimize adherence further.

Night-to-night variability in respiratory parameters in children and adolescents examined for obstructive sleep apnea

INTRODUCTION

The diagnosis of obstructive sleep apnea (OSA) is routinely based on just a single night's sleep examination. The night-to-night variability in children and adolescents has previously been investigated using type 4 sleep monitors or PSG. However, there is a lack of studies investigating the night-to-night variability when using type 3 sleep monitors. Therefore, the main purpose was to investigate the night-to-night variability in respiratory parameters in children and adolescents using a portable type 3 monitor. Furthermore, the purpose was to investigate the clinical relevance of night-to-night variability.

METHODS

The study population was recruited from an ongoing research project concerning the effect of weight loss in children and adolescents with OSA and overweight/obesity. The inclusion criterion was the successful recording of two consecutive nights of sleep. Sleep examinations were recorded at home using the Nox T3 device and then blindly scored by the same registered polysomnographic technologist. To compare the respiratory parameters measured each night, a paired t-test or a Wilcoxon signed-rank test was used. The apnea-hypopnea index (AHI) was further described graphically with a scatter plot and a Bland-Altman plot. The presence and severity of OSA were described in tables.

RESULTS

A total of 30 children and adolescents with a median age of 14.8 years were included. When comparing respiratory parameters between nights, all p-values derived from paired t-tests and Wilcoxon signed-rank tests were >0.05. When considering the graphical depictions of AHI, it was evident that for some participants AHI measurements varied widely from night to night. Regarding the presence of OSA, 27% of participants changed diagnostic category between nights and 40% of those with a normal AHI on the first night had OSA on the second night. Regarding OSA severity, 50% of participants changed severity category between nights.

CONCLUSIONS

AHI measurements varied widely between nights in some children and adolescents leading to frequent changes in both diagnosis and severity of OSA from night to night. We therefore suggest the presence of a clinically relevant night-to-night variability which should be taken into account when diagnosing pediatric OSA.

Serum miR-92a is Elevated in Children and Adults with Obstructive Sleep Apnea

BACKGROUND

Obstructive Sleep Apnea (OSA) is a highly prevalent condition that is associated with several comorbidities including cardiovascular disease (CVD). Recent studies have revealed mixed results as to whether standard OSA therapy reverses CVD in adult patients. Thus, many advocate for earlier recognition of OSA induced CVD, as early as childhood, to prompt treatment antecedent to the onset of irreversible CVD. Here we investigated if the serum level of miR-92a, a known biomarker for CVD, can be used to identify patients with OSA in both children and adults.

METHODS

Consecutive snoring patients undergoing polysomnography were recruited for determination of circulating miR-92a, in addition to inflammatory and metabolic profiles. We assessed whether circulating miR-92a was associated with OSA severity.

RESULTS

Using two separate cohorts of adults (n=57) and children (n=13), we report a significant increase in the serum level of miR-92a in patients with severe OSA (p=0.021) and further demonstrate a significant correlation (Spearman rank correlation 0.308, p=0.010) with serum miR-92a levels and the apnea hypopnea index (AHI), a primary measure of OSA severity. Stepwise regression analysis revealed that serum miR-92a levels were independently associated with AHI (ß=0.332, p=0.003), age (ß=0.394, p=0.002) and LDL cholesterol levels (ß=0.368, p=0.004).

CONCLUSION

Our study is the first to establish that miR-92a is a useful biomarker for OSA severity in both children and adults. Given the canonical role of miR-92a on endothelial dysfunction, miR-92a may be useful to identify early onset CVD in OSA patients or stratify patient CVD risk to identify those that may benefit from earlier OSA treatment.

Agreement between manual and automatic analyses of home sleep examinations in pediatric obstructive sleep apnea

Aim: Home sleep testing is becoming more common in the diagnostics of pediatric obstructive sleep apnea. The aim was to examine the agreement between manual and automatic analyses of home sleep examinations in children and adolescents. Materials & methods: Sleep examinations recorded with a type 3 sleep monitor (Nox T3) were analyzed manually by a registered polysomnographic technologist and automatically with Noxturnal version 5.1. Results: 51sleep examinations on children and adolescents with a median age of 13.6 years were included. The median manual apnea–hypopnea index (AHI) was 2.7 (range 0.2 to 28.2), while the median automatic AHI was 11.9 (range 4.2 to 45.6; p < 0.001). Conclusion: The agreement between manual and automatic analyses was poor. The AHI was consistently overestimated by automatic analysis.

OSA and Cardiovascular Risk in Pediatrics

OSA occurs in approximately 1% to 5% of children in the United States. Long-term cardiovascular risks associated with OSA in the adult population are well documented. Although changes in BP regulation occur in children with OSA, the pathways leading to chronic cardiovascular risks of OSA in children are less clear. Risk factors associated with cardiovascular disease in adult populations could carry the same future risk for children. It is imperative to determine whether known mechanisms of cardiovascular diseases in adults are like those that lead to pediatric disease. Early pathophysiologic changes may lead to a lifetime burden of cardiovascular disease and early mortality. With this perspective in mind, our review discusses pathways leading to cardiovascular pathology in children with OSA and provides a comprehensive overview of recent research findings related to cardiovascular sequelae in the pediatric population.

Circadian Dysregulation: The Next Frontier in Obstructive Sleep Apnea Research

OBJECTIVE

To review the effects of the circadian clock on homeostasis, the functional interaction between the circadian clock and hypoxia-inducible factors, and the role of circadian dysregulation in the progression of cardiopulmonary disease in obstructive sleep apnea (OSA).

DATA SOURCES

The MEDLINE database was accessed through PubMed.

REVIEW METHODS

A general review is presented on molecular pathways disrupted in OSA, circadian rhythms and the role of the circadian clock, hypoxia signaling, crosstalk between the circadian and hypoxia systems, the role of the circadian clock in cardiovascular disease, and implications for practice. Studies included in this State of the Art Review demonstrate the potential contribution of the circadian clock and hypoxia in animal models or human disease.

CONCLUSIONS

Molecular crosstalk between the circadian clock and hypoxia-inducible factors has not been evaluated in disease models of OSA.

IMPLICATIONS FOR PRACTICE

Pediatric OSA is highly prevalent and, if left untreated, may lead to cardiopulmonary sequelae. Changes in inflammatory markers that normally demonstrate circadian rhythmicity are also seen among patients with OSA. Hypoxia-inducible transcription factors interact with core circadian clock transcription factors; however, the interplay between these pathways has not been elucidated in the cardiopulmonary system. This gap in knowledge hinders our ability to identify potential biomarkers of OSA and develop alternative therapeutic strategies. A deeper understanding of the mechanisms by which OSA impinges on clock function and the impact of clock dysregulation on the cardiopulmonary system may lead to future advancements for the care of patients with OSA. The aim of this review is to shed light on this important clinical topic.

Association of Adenotonsillectomy With Blood Pressure Among Hypertensive and Nonhypertensive Children With Obstructive Sleep Apnea

Importance

Hypertension in childhood may continue into adulthood and lead to adverse cardiovascular outcomes. Evidence suggests that adenotonsillectomy for childhood obstructive sleep apnea (OSA) may be associated with blood pressure (BP) improvement. However, how adenotonsillectomy is associated with BP in hypertensive and nonhypertensive children with OSA remains unclear.

Objective

To investigate disparities in BP changes after adenotonsillectomy in hypertensive and nonhypertensive children with OSA.

Design, Setting, and Participants

From January 1, 2010, to April 30, 2016, children (aged <18 years) with symptoms of OSA treated at National Taiwan University Hospital were enrolled in this retrospective case series study.

Interventions

Children underwent polysomnography for diagnosis of OSA (apnea-hypopnea index >1). All children with OSA underwent adenotonsillectomy.

Main Outcomes and Measures

Preoperative and postoperative overnight polysomnographic data were obtained. Office BP was measured in a sleep center before (nocturnal BP) and after (morning) polysomnography.

Results

A total of 240 nonobese children (mean [SD] age, 7.3 [3.0] years; 160 [66.7%] male and 80 [33.3%] female) with OSA were recruited. Postoperatively, the apnea-hypopnea index decreased significantly from 12.1 to 1.7 events per hour (95% CI of difference, -12.3 to -8.4 events per hour). The whole cohort had a significant decrease in nocturnal diastolic BP (66.9 to 64.5 mm Hg; 95% CI of difference, -4.1 to -0.7 mm Hg) and morning diastolic BP (66.9 to 64.4 mm Hg; 95% CI of difference, -4.2 to -0.8 mm Hg). The number (percentage) of patients with diastolic BP in the greater than 95th percentile decreased significantly nocturnally (48 [20.0%] to 33 [13.8%]; 95% CI of difference, -12.1% to -0.4%) and in the morning (52 [21.7%] to 34 [14.2%]; 95% CI of difference, -13.6% to -1.4%). Postoperatively, hypertensive children had a significant decrease in all BP measures, including mean (SD) nocturnal and morning systolic BP (nocturnal: 107.5 [8.6] mm Hg; morning: 106.0 [9.4] mm Hg), systolic BP index (nocturnal: -4.3 [8.6]; morning: -5.7 [8.5]), diastolic BP (nocturnal: 65.1 [11.5] mm Hg; morning: 64.4 [10.1] mm Hg), and diastolic BP index (nocturnal: -10.7 [17.3]; morning: -11.6 [15.7]), whereas the nonhypertensive group had a slight increase in nocturnal systolic BP (103.8 to 105.9 mm Hg; 95% CI of difference, 0.4-3.9 mm Hg). A generalized estimating equation model for subgroup comparisons revealed that children with hypertension, compared with those without, had greater improvement in all BP measures.

Conclusions and Relevance

Hypertensive children with OSA had a significant improvement in BP after adenotonsillectomy. Hypertensive children with OSA should be screened and treated by adenotonsillectomy because proper treatment not only eases OSA symptoms but also potentially prevents future cardiovascular and end-organ disease.

Altered Regional Brain Cortical Thickness in Pediatric Obstructive Sleep Apnea

Rationale

Obstructive sleep apnea (OSA) affects 2–5% of all children and is associated with cognitive and behavioral deficits, resulting in poor school performance. These psychological deficits may arise from brain injury, as seen in preliminary findings of lower gray matter volume among pediatric OSA patients. However, the psychological deficits in OSA are closely related to functions in the cortex, and such brain areas have not been specifically assessed. The objective was to determine whether cortical thickness, a marker of possible brain injury, is altered in children with OSA.

Methods

We examined regional brain cortical thicknesses using high-resolution T1-weighted magnetic resonance images in 16 pediatric OSA patients (8 males; mean age ± SD = 8.4 ± 1.2 years; mean apnea/hypopnea index ± SD = 11 ± 6 events/h) and 138 controls (8.3 ± 1.1 years; 62 male; 138 subjects from the NIH Pediatric MRI database) to identify cortical thickness differences in pediatric OSA subjects.

Results

Cortical thinning occurred in multiple regions including the superior frontal, ventral medial prefrontal, and superior parietal cortices. The left side showed greater thinning in the superior frontal cortex. Cortical thickening was observed in bilateral precentral gyrus, mid-to-posterior insular cortices, and left central gyrus, as well as right anterior insula cortex.

Conclusion

Changes in cortical thickness are present in children with OSA and likely indicate disruption to neural developmental processes, including maturational patterns of cortical volume increases and synaptic pruning. Regions with thicker cortices may reflect inflammation or astrocyte activation. Both the thinning and thickening associated with OSA in children may contribute to the cognitive and behavioral dysfunction frequently found in the condition.

Sleep and the Cardiovascular System in Children

Subspecialty pediatric practice provides comprehensive medical care for a range of ages, from premature infants to children, and often includes adults with complex medical and surgical issues that warrant multidisciplinary care. Normal physiologic variations involving different body systems occur during sleep and these vary with age, stage of sleep, and underlying health conditions. This article is a concise review of the cardiovascular (CV) physiology and pathophysiology in children, sleep-disordered breathing (SDB) contributing to CV morbidity, congenital and acquired CV pathology resulting in SDB, and the relationship between SDB and CV morbidity in different clinical syndromes and systemic diseases in the expanded pediatric population.

Pediatric Obstructive Sleep Apnea

Screening for obstructive sleep apnea (OSA) with in-laboratory polysomnography is recommended for children with sleep disordered breathing. Adenotonsillectomy is the first-line therapy for pediatric OSA, although intranasal steroids and montelukast can be considered for those with mild OSA and continuous positive airway pressure for those with moderate to severe OSA awaiting surgery, poor surgical candidates or persistent OSA. Bony or soft tissue upper airway surgery is reasonable for children failing medical management or those with persistent OSA following adenotonsillectomy. Weight loss and oral appliance therapy are also useful. A multi-modality approach to diagnosis and treatment is preferred.

Trends in Inpatient Pediatric Polysomnography for Laryngomalacia and Craniofacial Anomalies

OBJECTIVE

Increasingly, laryngomalacia and craniofacial anomalies are recognized as risk factors for obstructive sleep apnea. We sought to determine whether children with these diagnoses have become more likely to undergo inpatient polysomnogram (PSG) over time and to identify evolving trends in PSG utilization.

METHODS

Retrospective analysis of the Kids' Inpatient Database from 2003 to 2012. Children <21 years who underwent PSG were included. Weighted comparisons of clinical/demographic characteristics of patients undergoing PSG were performed, as were associations between clinical and demographic patient characteristics and performance of inpatient PSG.

RESULTS

Between 2003 and 2012, PSG procedures decreased from 1266 to 829 (P < .001). Among children who underwent PSG, mean age decreased from 3.9 ± 5.1 to 3.1 ± 5.2 years (P = .001), and the frequency of age <1 year increased from 47.8% to 59.5% (P < .001). The frequency of laryngomalacia increased from 2.5% to 14.3% (P < .001), while the frequency of craniofacial anomalies increased from 6.2% to 19.4% (P < .001). Laryngomalacia and craniofacial anomalies were predictive of undergoing inpatient PSG in both timeframes.

CONCLUSION

Despite decreasing PSG volumes, diagnoses of laryngomalacia and craniofacial anomalies comprised increasing fractions of children undergoing inpatient PSG between 2003 and 2012. Laryngomalacia and craniofacial anomalies were also predictive of inpatient PSG use in both timeframes.

Pupillometric findings in children with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) leads to intermittent hypoxia, activation of the sympathetic nervous system, and eventually cardiovascular morbidity. Alterations in autonomic nervous system (ANS) tone and reflexes are likely to play major roles in OSA-associated morbidities, and have been identified in a subset of children with OSA.

OBJECTIVES

To evaluate whether pupillometry, a noninvasive and rapid bedside test for the assessment of autonomic nervous system dysfunction (ANS), would detect abnormal ANS function in children with OSA.

METHODS

Children ages 2-12 years underwent polysomnography (PSG), and were divided based on PSG findings into two groups; Habitual Snorers (HS; AHI < 1 h/TST, n = 17) and OSA (AHI > 1 h/TST, n = 49), the latter then sub-divided into AHI severity categories (>1 but <5, >5 but <10, and >10 h/TST). Pupillometric measurements were performed during the clinic visit in a dark room using an automated pupillometer device.

RESULTS

A total of 66 subjects with a mean age of 7.3 ± 2.6 years were recruited. There were no statistically significant differences between any of the groups, even when comparing severe OSA (n = 15) and HS in any of the measures related to pupillary reflexes. However, mild, yet significant increases in systolic blood pressure and morning plasma norepinephrine levels were detected in the severe OSA group.

CONCLUSION

Although ANS perturbations are clearly present in a proportion of children with OSA, particularly those with severe disease, pupillary responses do not appear to provide a sensitive method for the detection of ANS dysfunction in OSA children.

A 4-year prospective follow-up study of childhood OSA and its association with BP

BACKGROUND

Childhood OSA is a prevalent condition associated with raised BP as documented in cross-sectional studies. This study aimed to determine whether baseline or change in OSA severity was associated with ambulatory BP at 4-year follow-up.

METHODS

Children who participated in our previous OSA prevalence research were invited to undergo a repeat overnight sleep study and 24-h ambulatory BP monitoring in this 4-year follow-up study. BP parameters of subjects with differing baseline OSA severity, that is, obstructive apnea-hypopnea index (OAHI) < 1/h, 1 to 5/h, and > 5/h, were compared. Overweight and normal-weight children were analyzed separately.

RESULTS

One hundred eighty-five of 306 subjects (60%) were included in the analysis, of whom 58 were overweight at baseline. Linear increasing trends of wake systolic BP (SBP), wake diastolic BP (DBP), and sleep SBP z scores at follow-up were found across groups of increasing baseline OSA severity in the normal weight but not in the overweight subgroup. After adjusting for BMI z score, baseline OAHI was independently associated with all BP z scores at follow-up but not associated with changes in BP z scores across 4 years. On the other hand, change in OAHI was independently associated with sleep SBP and DBP z scores at follow-up and with changes in sleep SBP and DBP z scores across 4 years.

CONCLUSIONS

This study provides longitudinal data as additional proof that childhood OSA is associated with elevated BP independent of obesity.

A systematic review and meta-analysis of cohort studies of echocardiographic findings in OSA children after adenotonsilectomy

CONTEXT

There is evidence that OSA in children can be associated with acute and chronic effects on the cardiovascular system due to repetitive episodes of apnea and hypoxemia.

OBJECTIVE

To assess whether there is an association between OSA and echocardiographic findings in children and whether that association persists after adenotonsillectomy.

DATA SOURCES

A literature search was conducted based on PUBMED, EMBASE and LILACS.

STUDY SELECTION

Children with OSA and children who did not have OSA, who were aged ≤12 years.

DATA EXTRACTION

Two reviewers extracted data independently; the risk of bias was assessed by examining the selected sample, the recruitment method, completeness of follow up, and blinding.

RESULTS

Seven studies met all the inclusion criteria and methodological requirements. There was a significant difference with elevated mean pulmonary arterial pressure levels in OSA participants compared to those without OSA at preoperative assessment [mean difference (MD) 8.67; confidential interval (CI) 95% 6.09, 11.25]. OSA participants showed a statistically significant increased interventricular septum (IVS) thickness (mm) [MD 0.60; CI 95% 0.09, 1.11]; and right ventricular (RV) dimension (cm/m) [MD 0.19; CI 95% 0.10, 0.28]. There was also a significant increase in right ventricular (RV) dimension (cm/m) [MD 0.10; CI 95% 0.05, 0.14] in OSA children.

CONCLUSION

There is moderate quality evidence regarding possible association between OSA and right heart repercussions. More prognosis studies are needed, to allow the combination of results in a meta-analysis.

Reduced exercise capacity in Greek children with mild to moderate obstructive sleep apnea syndrome

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is a common disease that is increasingly recognized among pediatric population. The exercise capacity of adults with OSAS has been demonstrated to be impaired, but there are no data about pediatric exercise response.

AIM

The aim of this study was to evaluate cardiopulmonary response to exercise in children with OSAS and to correlate exercise capacity and severity of OSAS.

METHODS

Twenty-seven children with habitual snoring (Group A) (mean age 10.5 ± 1.8 years) referred for overnight polysomnography and 13 apparently healthy controls (mean age 11 ± 1.5 years) were recruited. According to the apnea hypopnea index (AHI) group A consisted of 15 (55.6%) children with mild OSAS and 12 (44.4%) with moderate-severe OSAS. All children completed a maximal ramping cardiopulmonary exercise test (CPET) on cycle ergometer.

RESULTS

According to CPET children with OSAS had significantly lower VO2max (40.3 ± 8.4 ml/kg/min vs. 47.6 ± 7.9 ml/kg/min, P = 0.013) significantly lower VO2max (%) (77.7 ± 15 vs. 92.9 ± 10.5, P = 0.002), lower maximum heart-rate at peak exercise (86.6 ± 8.8 beat/min vs. 90.6 ± 7.2 beat/min) and higher systolic blood pressure level at peak exercise (145 ± 27.4 mmHg vs. 143.92 ± 20 mmHg) compared to control group.

CONCLUSION

The present study demonstrates that young patients with OSAS, even with mild OSAS, had reduced exercise capacity as compared to control group.

Nocturnal dipping is preserved in children with sleep disordered breathing regardless of its severity

OBJECTIVE

Sleep disordered breathing (SDB) in adults has been associated with a loss of nocturnal dipping in blood pressure (BP) and heart rate, however, there have been limited studies in children. We measured BP non-invasively and continuously overnight in 105 children aged 7-12 with a range of severities of SDB and 36 non-snoring controls to examine nocturnal dipping profiles.

STUDY DESIGN

Children with SDB were divided into three severity groups according to their obstructive apnea hypopnea index. Nocturnal dipping profiles across sleep stages were described both as a proportion of children exhibiting a ≥10% fall in systolic arterial pressure (SAP) and heart rate (HR) from wake to sleep and according to SAP sleep/SAP wake ratio as extreme dippers (ratio ≤ 0.8), dippers (ratio < 0.8 and ≤0.9), non-dippers (ratio < 0.9 and ≤1.0), and reverse dippers (ratio > 1.0).

RESULTS

The mean fall in BP between wake and NREM 1/2, SWS, and REM sleep was not different between the groups and there were no differences between the dipping profiles of children in each group.

CONCLUSIONS

SDB did not alter nocturnal dipping patterns of BP and HR compared to controls, a finding which may suggest that these young children have not been exposed to the effects of SDB long enough or that SDB severity was not great enough to affect nocturnal dipping profiles. However, further studies are required to determine if the elevated BP previously reported in this group of children will have long-term effects on the cardiovascular system.

Obstructive sleep apnea in children: a critical update

Obstructive sleep apnea (OSA) in children is a highly prevalent disorder caused by a conglomeration of complex pathophysiological processes, leading to recurrent upper airway dysfunction during sleep. The clinical relevance of OSA resides in its association with significant morbidities that affect the cardiovascular, neurocognitive, and metabolic systems. The American Academy of Pediatrics recently reiterated its recommendations that children with symptoms and signs suggestive of OSA should be investigated with polysomnography (PSG), and treated accordingly. However, treatment decisions should not only be guided by PSG results, but should also integrate the magnitude of symptoms and the presence or absence of risk factors and signs of OSA morbidity. The first-line therapy in children with adenotonsillar hypertrophy is adenotonsillectomy, although there is increasing evidence that medical therapy, in the form of intranasal steroids or montelukast, may be considered in mild OSA. In this review, we delineate the major concepts regarding the pathophysiology of OSA, its morbidity, diagnosis, and treatment.

Sleep problems and cardiovascular function in children

OBJECTIVE

To assess the associations of sleep problems with 24-hour ambulatory blood pressure and cardiovascular reactivity in children.

METHODS

Sleep problems in 285 term-born, healthy 8-year-olds (mean [standard deviation] = 8.1 [0.3] years) were measured with a parent-rated Sleep Disturbance Scale for Children. Ambulatory blood pressure (n = 241) was measured for 24 hours (41% nonschool days) with an oscillometric device. The children (n = 274) underwent the Trier Social Stress Test for Children during which blood pressure, electrocardiography, and thoracic impedance were recorded and processed offline to give measures of cardiovascular and autonomic function.

RESULTS

No associations were found between sleep problems and 24-hour ambulatory blood pressure. Children with sleep breathing disorders (n = 5) had higher baseline sympathetic vascular activity (p = .014) and higher heart rate (p = .044) and sympathetic cardiac activity (p = .031) in reaction to stress. Children with disorders of excessive somnolence (n = 55) had higher baseline parasympathetic activity (p = .016). None of the associations remained significant after controlling for multiple testing.

CONCLUSIONS

Our results suggest that in a healthy community sample of prepubertal children, sleep problems are not associated with an unhealthy cardiovascular phenotype at this age. However, associations may be underestimated because of the low prevalence of sleep breathing disorders in this sample and may not generalize to older populations.

Preschool children with obstructive sleep apnea: the beginnings of elevated blood pressure?

STUDY OBJECTIVES

In adults and older children, snoring and obstructive sleep apnea (OSA) are associated with elevated blood pressure (BP). However, BP has not been assessed in preschool children, the age of highest OSA prevalence. We aimed to assess overnight BP in preschool children with snoring and OSA using pulse transit time (PTT), an inverse continuous indicator of BP changes.

DESIGN

Overnight polysomnography including PTT. Children were grouped according to their obstructive apnea-hypopnea index (OAHI); control (no snoring, with OAHI of one event or less per hour), primary snoring (OAHI one event or less per hour), mild OSA (OAHI greater than one event to five events per hour) and moderate-severe OSA (OAHI more than five events per hour).

SETTING

Pediatric sleep laboratory.

PATIENTS

There were 128 clinically referred children (aged 3-5 years) and 35 nonsnoring community control children.

MEASUREMENT AND RESULTS

PTT was averaged for each 30-sec epoch of rapid eye movement (REM) or nonrapid eye movement (NREM) sleep and normalized to each child's mean wake PTT. PTT during NREM was significantly higher than during REM sleep in all groups (P < 0.001 for all). During REM sleep, the moderate-severe OSA group had significantly lower PTT than the mild and primary snoring groups (P < 0.05 for both). This difference persisted after removal of event-related PTT changes.

CONCLUSIONS

Moderate-severe OSA in preschool children has a significant effect on pulse transit time during REM sleep, indicating that these young children have a higher baseline BP during this state. We propose that the REM-related elevation in BP may be the first step toward development of daytime BP abnormalities. Given that increased BP during childhood predicts hypertension in adulthood, longitudinal studies are needed to determine the effect of resolution of snoring and/or OSA at this age.

Blood pressure regulation, autonomic control and sleep disordered breathing in children

Sleep disordered breathing (SDB) ranges in severity from primary snoring (PS) to obstructive sleep apnoea (OSA). In adults, SDB is associated with adverse cardiovascular consequences which are mediated, in part, by autonomic dysfunction. Although SDB is common in children, fewer paediatric studies have investigated these cardiovascular effects. Initial research focused on those with OSA, indeed children with PS were occasionally utilised as the comparison control group. However, it is essential to understand the ramifications of this disorder in all its severities, as currently the milder forms of SDB are often untreated. Methodologies used to assess autonomic function in children with SDB include blood pressure (BP), BP variability, baroreflex sensitivity, heart rate variability, peripheral arterial tonometry and catecholamine assays. The aim of this review was to summarise the findings of paediatric studies to date and explore the relationship between autonomic dysfunction and SDB in children, paying particular attention to the roles of disease severity and/or age. This review found evidence of autonomic dysfunction in children with SDB during both wakefulness and sleep. BP dysregulation, elevated generalised sympathetic activity and impairment of autonomic reflexes occur in school-aged children and adolescents with SDB. The adverse effects of SDB seem somewhat less in young children, although more studies are needed. There is mounting evidence that the cardiovascular and autonomic consequences of SDB are not limited to those with OSA, but are also evident in children with PS. The severity of disease and age of onset of autonomic consequences may be important guides for the treatment of SDB.

Ambulatory blood pressure monitoring in Chinese children with obstructive sleep apnea/hypopnea syndrome

OBJECTIVE

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a common sleep problem. The aim of this study is to investigate the association between OSAHS and blood pressure (BP) in snoring children.

METHODS

Snoring children were recruited from January 2009 to December 2010. Clinical history was taken accompanied by a physical examination and polysomnography were performed. A child with an apnea/hypopnea index (AHI) greater than 5 hr(-1) or obstructive apnea index (OAI) greater than 1 hr(-1) was diagnosed as having OSAHS. Ambulatory BP monitoring was performed for each child. BP load, BP index and nocturnal BP dipping were calculated for each child.

RESULTS

One hundred forty-five children with snoring were recruited and 107 of them were diagnosed with OSAHS. There were no differences between those with or without OSA in age or gender distribution. The OSAHS children had higher mean nighttime systolic and diastolic BP, increased BP load, and decreased nocturnal BP dipping compared to the non-OSAHS children (SBP: P = 0.03, DBP: P < 0.001, BP load: P = 0.001, SBP dipping: P = 0.03, DBP dipping: P = 0.04). Multiple regression analysis showed that mean nighttime systolic BP was related to age, obesity, and oxygen desaturation index (ODI) (P = 0.04, 0.03, and 0.02 respectively), while mean nighttime diastolic BP was related to obesity and ODI (P = 0.03 and 0.04, respectively).

CONCLUSIONS

OSAHS children had a higher nocturnal BP than non-OSAHS children and dysregulation of BP control reflected by decreased nocturnal BP dipping. Frequency of oxygen desaturation, apneas, and obesity were related to BP.

Systematic Review of Effects of Adenotonsillectomy on Cardiovascular Parameters in Children with Obstructive Sleep Apnea

Objective

To systematically review current studies on the effects of adenotonsillectomy (T&A) for obstructive sleep apnea (OSA) on cardiovascular parameters in children.

Data Sources

PubMed database.

Review Methods

A comprehensive PubMed MeSH search was done between 1970 and 2012.

Results

Fourteen articles were included. The total number of children was 418. The mean sample size was 30 (range, 1-62), and the mean age of the sample population was 6 years (range, 2-10 years). Criteria used for the diagnosis of OSA ranged from full-night polysomnography (PSG) to clinical parameters. Three studies had results from preoperative and postoperative PSG. Cardiovascular parameters studied included blood pressure, heart rate, cardiac morphology, and cardiac function. All studies reported an improvement in cardiovascular parameters and OSA symptoms after surgery. Three studies reported improvement in blood pressure, 6 reported improvement in mean pulmonary artery pressures, 7 reported improvement in echocardiographic findings, and 1 reported a decrease in pulse rate and pulse rate variability after T&A for OSA.

Conclusion

There is evidence that cardiovascular morbidities associated with OSA are potentially reversible. T&A may have a significant role in reversing the cardiovascular sequelae of OSA. However, there is a paucity of well-designed and powered studies to address this issue.

Preventing and Treating Obesity in Girls and Young Women to Curb the Epidemic

Obesity and its serious comorbidities, type 2 diabetes, coronary heart disease, hypertension, and dyslipidemia, have reached epidemic proportions in adults and children. Female obesity is more prevalent and, thus, has greater epidemiological importance: mothers transmit the disease epigenetically and genetically. Maternal obesity affects maternal health, pregnancy outcome, and fetal, neonatal, childhood, and ultimately adult morbidity and mortality. Obesity is easy to diagnose, as are most of its risk factors, yet very little progress has been made in preventing the disease. During a brief period of rapid early growth, there is imprinting of antecedents of adult obesity and obesity-related disease. Because of the rapidity of this early growth and the relative brevity of the critical period, early recognition and prompt intervention are necessary and possibly sufficient to prevent the development of obesity. Identification of inappropriate rapid weight gain through frequent weighing should trigger immediate adjustment of energy intake, a simple intervention in bottle-fed infants, the ones at greatest risk for becoming obese. This review presents a step-care strategy with fail-safe action levels starting with maternal education and diet, exercise, and behavior modification for mother and child and progressing to drug treatment and, in selected cases, laparoscopic surgery for young women of childbearing age in whom other measures have failed. This approach is predicated on the assumption that careful monitoring and responsive supplementation of potential deficiencies is easier to achieve, more cost-effective, and safer than effectively treating manifest obesity and its comorbidities in adults.

Diagnosis and management of childhood obstructive sleep apnea syndrome

OBJECTIVE

This technical report describes the procedures involved in developing recommendations on the management of childhood obstructive sleep apnea syndrome (OSAS).

METHODS

The literature from 1999 through 2011 was evaluated.

RESULTS AND CONCLUSIONS

A total of 3166 titles were reviewed, of which 350 provided relevant data. Most articles were level II through IV. The prevalence of OSAS ranged from 0% to 5.7%, with obesity being an independent risk factor. OSAS was associated with cardiovascular, growth, and neurobehavioral abnormalities and possibly inflammation. Most diagnostic screening tests had low sensitivity and specificity. Treatment of OSAS resulted in improvements in behavior and attention and likely improvement in cognitive abilities. Primary treatment is adenotonsillectomy (AT). Data were insufficient to recommend specific surgical techniques; however, children undergoing partial tonsillectomy should be monitored for possible recurrence of OSAS. Although OSAS improved postoperatively, the proportion of patients who had residual OSAS ranged from 13% to 29% in low-risk populations to 73% when obese children were included and stricter polysomnographic criteria were used. Nevertheless, OSAS may improve after AT even in obese children, thus supporting surgery as a reasonable initial treatment. A significant number of obese patients required intubation or continuous positive airway pressure (CPAP) postoperatively, which reinforces the need for inpatient observation. CPAP was effective in the treatment of OSAS, but adherence is a major barrier. For this reason, CPAP is not recommended as first-line therapy for OSAS when AT is an option. Intranasal steroids may ameliorate mild OSAS, but follow-up is needed. Data were insufficient to recommend rapid maxillary expansion.

Chemoreceptors, baroreceptors, and autonomic deregulation in children with obstructive sleep apnea

Obstructive sleep apnea (OSA) is highly prevalent sleep disorder of breathing in both adults and children that is fraught with substantial cardiovascular morbidities, the latter being attributable to a complex interplay between intermittent hypoxia (IH), episodic hypercapnia, recurrent large intra-thoracic pressure swings, and sleep disruption. Alterations in autonomic nervous system function could underlie the perturbations in cardiovascular, neurocognitive, immune, endocrine and metabolic functions that affect many of the patients suffering from OSA. Although these issues have received substantial attention in adults, the same has thus far failed to occur in children, creating a quasi misperception that children are protected. Here, we provide a critical overview of the evidence supporting the presence of autonomic nervous system (ANS) perturbations in children with OSA, draw some parallel assessments to known mechanisms in rodents and adult humans, particularly, peripheral and central chemoreceptor and baroreceptor pathways, and suggest future research directions.

The Endothelium as a Target in Pediatric OSA

Pediatric sleep disordered breathing has emerged in the last few decades as a highly prevalent condition by virtue of its major morbidities encompassing the central nervous, cardiovascular, and metabolic systems. In this context, improved understanding of the pathophysiological mechanisms underlying the cellular and organ injury and repair mechanisms, and the variance of the phenotype at any level of disease severity is all the more critical if appropriate personalized therapies are to be developed in the future. In this paper, the current evidence and hypothetical framework pointing to the endothelium as a primary cellular target for many of the morbidities of pediatric sleep apnea is reviewed, and particular emphasis on the recruitment of the endothelial cell lineage will be explored. It is hoped that this perspective will foster both expansion and acceleration of discovery efforts aiming to ultimately prevent the potentially lifelong consequences of sleep apnea during childhood.

Ambulatory blood pressure monitoring in children with obstructive sleep apnea and primary snoring

OBJECTIVE

To evaluate the systemic blood pressure (BP) during daytime and nighttime in children with sleep breathing disorders (SBD) and compare parameters of BP in children with diagnosis of obstructive sleep apnea syndrome (OSA) to those one with primary snoring (PS).

METHODS

Children, both genders, aged from 8 to 12 years, with symptoms of SBD realized an overnight polysomnography followed by a 24h recording of ambulatory BP.

RESULTS

All subjects presented with a history of snoring 7 nights per week. Children who have apnea/hipoapnea index ≥ four or a apnea index ≥ one presented a mean BP of 93±7mmHg and 85±9mmHg diurnal and nocturnal respectively whereas children who have a apnea/hipoapnea < four or a apnea index < one presented 90±7mmHg and 77±2mmHg. Eight children out of fourteen, from OSA group, lost the physiologic nocturnal dipping of the blood pressure. Among OSA children 57% were considered non-dippers. Two (16%) have presented absence of nocturnal dipping among children with primary snoring. The possibility of OSA children loosing physiologic blood pressure dipping was 6.66 higher than the possibilities of patients from PS group.

DISCUSSION

Our results indicate that children with sleep apnea syndrome exhibit a higher 24h blood pressure when compared with those of primary snoring in form of decreased degree of nocturnal dipping and increased levels of diastolic and mean blood pressure, according to previous studies in literature. OSA in children seems to be associated to the development of hypertension or other cardiovascular disease.

Sympathetic and catecholaminergic alterations in sleep apnea with particular emphasis on children

Sleep is involved in the regulation of major organ functions in the human body, and disruption of sleep potentially can elicit organ dysfunction. Obstructive sleep apnea (OSA) is the most prevalent sleep disorder of breathing in adults and children, and its manifestations reflect the interactions between intermittent hypoxia, intermittent hypercapnia, increased intra-thoracic pressure swings, and sleep fragmentation, as elicited by the episodic changes in upper airway resistance during sleep. The sympathetic nervous system is an important modulator of the cardiovascular, immune, endocrine and metabolic systems, and alterations in autonomic activity may lead to metabolic imbalance and organ dysfunction. Here we review how OSA and its constitutive components can lead to perturbation of the autonomic nervous system in general, and to altered regulation of catecholamines, both of which then playing an important role in some of the mechanisms underlying OSA-induced morbidities.

The role of polysomnography in diagnosing and treating obstructive sleep apnea in pediatric patients

Obstructive sleep apnea in children is associated with serious neurocognitive and cardiovascular morbidity, systemic inflammation, and increased health care use, yet remains underdiagnosed. Although the prevalence of obstructive sleep apnea is 1-3% in the pediatric population, the prevalence of primary snoring (PS) is estimated to be 3-12%. The challenge for pediatricians is to differentiate PS from obstructive sleep apnea in a cost-effective, reliable, and accurate manner before recommending invasive or intrusive therapies, such as surgery or continuous positive airway pressure. The validity of polysomnography as the gold standard for diagnosing obstructive sleep apnea has been challenged, primarily related to concerns that abnormalities on polysomnography do not correlate well with adverse outcomes, that those abnormalities have statistical more than clinical significance, and that performing polysomnograms on all children who snore is a practical impossibility. The aim of this article is to review the clinical utility of diagnostic tests other than polysomnography to diagnose obstructive sleep apnea, to highlight the limitations and strengths of polysomnography, to underscore the threshold levels of abnormalities detected on polysomnography that correlate with morbidity, and to discuss what the practical implications are for treatment.

Obstructive sleep apnea syndrome in children

The clinical syndrome of obstructive sleep apnea (OSAS) in children is a distinct, yet somewhat overlapping disorder with the condition that occurs in adults, such that the clinical manifestations, polysomnographic findings, diagnostic criteria and treatment approaches need to be considered in an age-specific manner. Childhood OSAS has now become widely recognized as a frequent disorder and as a major public health problem. Pediatric OSAS, particularly when obesity is concurrently present, is associated with substantial end-organ morbidities and increased healthcare utilization. Although adenotonsillectomy (T&A) remains the first line of treatment, evidence in recent years suggests that the outcomes of this surgical procedure may not be as favorable as expected, such that post-T&A polysomnographic evaluation may be needed, especially in high-risk patient groups. In addition, incorporation of nonsurgical approaches for milder forms of the disorder and for residual OSAS after T&A is now being investigated.

Elevated blood pressure during sleep and wake in children with sleep-disordered breathing

OBJECTIVE

Sleep-disordered breathing (SDB) in adults has been associated with elevated blood pressure (BP); however, the effects of severity of SDB on BP in children are uncertain. We addressed this issue by measuring BP noninvasively and continuously during sleep in children with a range of severities of SDB and in a group of nonsnoring control children.

METHODS

A total of 105 children referred for assessment of SDB and 36 nonsnoring controls were studied. Routine polysomnography (PSG) was performed with continuous BP monitoring. Children were assigned to groups according to obstructive apnea/hypopnea index (OAHI). BP data were categorized as quiet awake (recorded before sleep onset), non-rapid eye movement sleep 1 and 2 combined, slow-wave sleep, and rapid eye movement sleep.

RESULTS

BP during awake before sleep onset and during overnight sleep was elevated by 10 to 15 mm Hg in the 3 SDB groups compared with the control group; this finding was independent of SDB severity. BP during stable sleep (with respiratory events and movements excluded) was also elevated in the children with OSA compared with the control group. BP was elevated in rapid eye movement sleep compared with the non-rapid eye movement sleep, and heart rate was higher during wake state than in all sleep states.

CONCLUSIONS

We recorded BP continuously overnight and found that SDB, regardless of the severity, was associated with increased BP during sleep and wake compared with nonsnoring control children. These findings highlight the importance of considering the cardiovascular effects of SDB of any severity in children, and the need to review current clinical management that focuses primarily on more severe SDB.

Executive summary of respiratory indications for polysomnography in children: an evidence-based review

OBJECTIVE

This comprehensive, evidence-based review provides a systematic analysis of the literature regarding the validity, reliability, and clinical utility of polysomnography for characterizing breathing during sleep in children. Findings serve as the foundation of practice parameters regarding respiratory indications for polysomnography in children.

METHODS

A task force of content experts performed a systematic review of the relevant literature and graded the evidence using a standardized grading system. Two hundred forty-three evidentiary papers were reviewed, summarized, and graded. The analysis addressed the operating characteristics of polysomnography as a diagnostic procedure in children and identified strengths and limitations of polysomnography for evaluation of respiratory function during sleep.

RESULTS

The analysis documents strong face validity and content validity, moderately strong convergent validity when comparing respiratory findings with a variety of relevant independent measures, moderate-to-strong test-retest validity, and limited data supporting discriminant validity for characterizing breathing during sleep in children. The analysis documents moderate-to-strong test-retest reliability and interscorer reliability based on limited data. The data indicate particularly strong clinical utility in children with suspected sleep related breathing disorders and obesity, evolving metabolic syndrome, neurological, neurodevelopmental, or genetic disorders, and children with craniofacial syndromes. Specific consideration was given to clinical utility of polysomnography prior to adenotonsillectomy (AT) for confirmation of obstructive sleep apnea syndrome. The most relevant findings include: (1) recognition that clinical history and examination are often poor predictors of respiratory polygraphic findings, (2) preoperative polysomnography is helpful in predicting risk for perioperative complications, and (3) preoperative polysomnography is often helpful in predicting persistence of obstructive sleep apnea syndrome in patients after AT. No prospective studies were identified that address whether clinical outcome following AT for treatment of obstructive sleep apnea is improved in association with routine performance of polysomnography before surgery in otherwise healthy children. A small group of papers confirm the clinical utility of polysomnography for initiation and titration of positive airway pressure support.

CONCLUSIONS

Pediatric polysomnography shows validity, reliability, and clinical utility that is commensurate with most other routinely employed diagnostic clinical tools or procedures. Findings indicate that the "gold standard" for diagnosis of sleep related breathing disorders in children is not polysomnography alone, but rather the skillful integration of clinical and polygraphic findings by a knowledgeable sleep specialist. Future developments will provide more sophisticated methods for data collection and analysis, but integration of polysomnographic findings with the clinical evaluation will represent the fundamental diagnostic challenge for the sleep specialist.

Practice parameters for the respiratory indications for polysomnography in children

BACKGROUND

There has been marked expansion in the literature and practice of pediatric sleep medicine; however, no recent evidence-based practice parameters have been reported. These practice parameters are the first of 2 papers that assess indications for polysomnography in children. This paper addresses indications for polysomnography in children with suspected sleep related breathing disorders. These recommendations were reviewed and approved by the Board of Directors of the American Academy of Sleep Medicine.

METHODS

A systematic review of the literature was performed, and the American Academy of Neurology grading system was used to assess the quality of evidence. RECOMMENDATIONS FOR PSG USE: 1. Polysomnography in children should be performed and interpreted in accordance with the recommendations of the AASM Manual for the Scoring of Sleep and Associated Events. (Standard) 2. Polysomnography is indicated when the clinical assessment suggests the diagnosis of obstructive sleep apnea syndrome (OSAS) in children. (Standard) 3. Children with mild OSAS preoperatively should have clinical evaluation following adenotonsillectomy to assess for residual symptoms. If there are residual symptoms of OSAS, polysomnography should be performed. (Standard) 4. Polysomnography is indicated following adenotonsillectomy to assess for residual OSAS in children with preoperative evidence for moderate to severe OSAS, obesity, craniofacial anomalies that obstruct the upper airway, and neurologic disorders (e.g., Down syndrome, Prader-Willi syndrome, and myelomeningocele). (Standard) 5. Polysomnography is indicated for positive airway pressure (PAP) titration in children with obstructive sleep apnea syndrome. (Standard) 6. Polysomnography is indicated when the clinical assessment suggests the diagnosis of congenital central alveolar hypoventilation syndrome or sleep related hypoventilation due to neuromuscular disorders or chest wall deformities. It is indicated in selected cases of primary sleep apnea of infancy. (Guideline) 7. Polysomnography is indicated when there is clinical evidence of a sleep related breathing disorder in infants who have experienced an apparent life-threatening event (ALTE). (Guideline) 8. Polysomnography is indicated in children being considered for adenotonsillectomy to treat obstructive sleep apnea syndrome. (Guideline) 9. Follow-up PSG in children on chronic PAP support is indicated to determine whether pressure requirements have changed as a result of the child's growth and development, if symptoms recur while on PAP, or if additional or alternate treatment is instituted. (Guideline) 10. Polysomnography is indicated after treatment of children for OSAS with rapid maxillary expansion to assess for the level of residual disease and to determine whether additional treatment is necessary. (Option) 11. Children with OSAS treated with an oral appliance should have clinical follow-up and polysomnography to assess response to treatment. (Option) 12. Polysomnography is indicated for noninvasive positive pressure ventilation (NIPPV) titration in children with other sleep related breathing disorders. (Option) 13. Children treated with mechanical ventilation may benefit from periodic evaluation with polysomnography to adjust ventilator settings. (Option) 14. Children treated with tracheostomy for sleep related breathing disorders benefit from polysomnography as part of the evaluation prior to decannulation. These children should be followed clinically after decannulation to assess for recurrence of symptoms of sleep related breathing disorders. (Option) 15. Polysomnography is indicated in the following respiratory disorders only if there is a clinical suspicion for an accompanying sleep related breathing disorder: chronic asthma, cystic fibrosis, pulmonary hypertension, bronchopulmonary dysplasia, or chest wall abnormality such as kyphoscoliosis. (Option) RECOMMENDATIONS AGAINST PSG USE: 16. Nap (abbreviated) polysomnography is not recommended for the evaluation of obstructive sleep apnea syndrome in children. (Option) 17. Children considered for treatment with supplemental oxygen do not routinely require polysomnography for management of oxygen therapy. (Option)

CONCLUSIONS

Current evidence in the field of pediatric sleep medicine indicates that PSG has clinical utility in the diagnosis and management of sleep related breathing disorders. The accurate diagnosis of SRBD in the pediatric population is best accomplished by integration of polysomnographic findings with clinical evaluation.

Autonomic cardiovascular tests in children with obstructive sleep apnea syndrome

STUDY OBJECTIVES

The aim of our study was to investigate cardiovascular autonomic activity during wakefulness, using cardiovascular tests, in a population of children with OSAS.

DESIGN

Prospective study.

SETTING

Sleep unit of an academic center.

PARTICIPANTS

We included 25 children (mean age 10.2 +/- 2.3 years) undergoing a diagnostic assessment for OSAS, and 25 age-matched healthy control subjects. All subjects underwent an overnight polysomnography and autonomic cardiovascular tests using parts of the Ewing test battery, which is a physiological test used for the assessment of autonomic function (head-up tilt test, Valsalva maneuver, deep breathing test).

MEASUREMENTS AND RESULTS

Eighteen of 25 children with OSAS (11 males, mean age 9.4 +/- 1.7 years) concluded the study. OSAS patients had higher systolic blood pressure, diastolic blood pressure, baseline heart rate, the 30:15 index (which represents the RR interval at the 15th and 30th beats during the head up tilt test), and delta diastolic and systolic blood pressure during the head-up tilt test, while the heart rate variability during the deep breathing test was lower, compared with controls. A positive correlation between systolic and diastolic blood pressure and the apnea-hypopnea index (AHI), and negative between AHI and both the 30:15 index and Valsalva ratio, were found. Stepwise linear regression analysis detected a negative correlation between AHI and the 30:15 index and Valsalva ratio, a positive correlation between overnight mean oxygen saturation and delta heart rate, and between AHI and delta systolic blood pressure.

CONCLUSIONS

Our data point to an increase in basal sympathetic activity during wakefulness and to an impaired reaction to several physiological stimuli, which is dependent on the severity of OSAS.

Urinary proteins for the diagnosis of obstructive sleep apnea syndrome

Approximately 2-3% of all children in the United States suffer from obstructive sleep apnea (OSA). This condition is characterized by repeated events of partial or complete obstruction of the upper airways during sleep leading to recurring episodes of hypercapnia, hypoxemia, and arousal throughout the night as well as snoring, which afflicts 7-10% of all children. Since clinical history and physical examination are unreliable in the differentiation between children with OSA and children with primary snoring (PS) who have no apparent alteration in sleep architecture, current diagnostic approaches for OSA require an overnight sleep study (ONP). ONP is onerous, relatively unavailable, labor intensive, and inconvenient, leading to long waiting periods and unnecessary delays in diagnosis and treatment. Development of noninvasive biomarker(s) capable of reliably distinguishing children with PS from those with OSA would greatly facilitate timely screening and diagnosis of OSA in children. Therefore, we hypothesized that proteomic strategies in the urine may permit the identification of biomarker(s) that reliably screen for OSA. In this study, time-of-flight mass spectrometry was used to profile proteins in the first morning void urines from children. We discovered that urocortins are increased in OSA and provide a noninvasive approach for quick and convenient diagnosis otf OSA in snoring children.

Acute cardiovascular changes with obstructive events in children with sleep disordered breathing

STUDY OBJECTIVES

Obstructive apneas in adults are associated with acute changes in blood pressure (BP) and heart rate (HR) that may contribute to poor cardiovascular outcome. Children with sleep disordered breathing (SDB) are similarly at risk for cardiovascular complications. We aimed to test the hypothesis that BP and HR are augmented during obstructive events in children equivalent to levels reported in adults.

DESIGN

Beat-by-beat mean arterial pressure (MAP) and HR were analyzed over the course of obstructive events (pre, early, late, and post-event) during NREM and REM sleep and compared using 2-way ANOVA with post hoc analyses.

SETTING

Pediatric sleep laboratory.

PATIENTS OR PARTICIPANTS

30 children (15M/15F) aged 7-12 y referred for investigation of SDB INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS

All children underwent overnight polysomnography with continuous BP recording. MAP and HR increased significantly from late to post event in both sleep states (mean +/- SEM, NREM: MAP, 74 +/- 3 to 93 +/- 3 mm Hg; HR, 76 +/- 2 to 97 +/- 2 bpm. REM: MAP, 76 +/- 3 to 89 +/- 3 mm Hg; HR, 76 +/- 2 to 91 +/- 2 bpm. P < 0.05 for all). NREM sleep state and arousal from sleep were significant independent predictors of the magnitude of cardiovascular change from late to post event (P < 0.05 for all).

CONCLUSIONS

Children with SDB experience significant changes in HR and BP during obstructive events with magnitudes that are similar to levels reported in adults. These changes are more pronounced during NREM sleep and with arousal. These acute cardiovascular changes may have important implications for poor cardiovascular outcome in children with OSA as repetitive cardiovascular perturbations may contribute to the development of hypertension.