Cardiovascular changes in children with obstructive sleep apnea and obesity after treatment with noninvasive ventilation

Comparing Sleep Patterns and Clinical Features between Preschool and School-Age Children with OSA

OBJECTIVE

This study aimed to evaluate sleep patterns and investigate differences in clinical features among young individuals with snoring and obstructive sleep apnea (OSA).

METHODS

Data from 213 children and adolescents who underwent polysomnography (PSG) for primary snoring or OSA were collected between July 2017 and December 2021. To analyze differences in sleep architecture, hypoxia levels, and other clinical features, the participants were divided into two age groups: a preschool group and a school-age group.

RESULTS

The school-age group had significantly higher apnea-hypopnea index, obstructive apnea index, oxygen desaturation index, and body mass index than the preschool group. Both the lowest and average oxygen saturation levels were lower in the school-age group. Adenoid hypertrophy was more prevalent in the preschool group. The rate of overweight or obesity was 35.6% in the preschool group and even 94.2% in the school-age group. There were higher percentages of N1 and N2 sleep stages, and lower percentages of N3 and REM sleep stages in the school-age group. The groups exhibiting moderate to severe OSA demonstrated significant alterations in the difference between sleeping and waking diastolic blood pressure.

CONCLUSION

There is a higher frequency of respiratory events among school-age children compared with their preschool peers. Moreover, alterations in sleep structure are more prominent in the school-age group. Adenoid hypertrophy may serve as the primary instigator of OSA in preschool children, whereas the predominant causes in school-age children may be obesity or excessive weight.

LEVEL OF EVIDENCE

Retrospective chart review, 3 Laryngoscope, 134:1472-1478, 2024.

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.

Using sleep heart rate variability to investigate the sleep quality in children with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is associated with impaired sleep quality and autonomic dysfunction. Adenotonsillectomy significantly improves subjective and objective sleep quality in children with OSA. However, the postoperative changes in heart rate variability (HRV) indices (indicators of cardiac autonomic function) and their importance remain inconclusive in childhood OSA. This retrospective case series aimed to investigate the association of sleep HRV indices, total OSA-18 questionnaire score (a subjective indicator of sleep quality) and polysomnographic parameters (objective indicators of sleep quality), and effects of adenotonsillectomy on HRV indices, total OSA-18 questionnaire score and polysomnographic parameters in children with OSA.

Methods

Seventy-six children with OSA were included in baseline analysis, of whom 64 (84%) completed at least 3 months follow-up examinations after adenotonsillectomy and were included in outcome analysis. Associations between baseline variables, and relationships with treatment-related changes were examined.

Results

Multivariable linear regression models in the baseline analysis revealed independent relationships between tonsil size and obstructive apnea-hypopnea index (OAHI), adenoidal-nasopharyngeal ratio and very low frequency (VLF) power of HRV (an indicator of sympathetic activity), and normalized low frequency power (an indicator of sympathetic activity) and OAHI. The outcome analysis showed that adenotonsillectomy significantly improved standard deviation of all normal-to-normal intervals, and high frequency power, QoL (in terms of reduced total OSA-18 questionnaire score), OAHI and hypoxemia. Using a conceptual serial multiple mediation model, % change in OSA-18 questionnaire score and % change in VLF power serially mediated the relationships between change in tonsil size and % change in OAHI.

Conclusions

The improvement in OAHI after adenotonsillectomy was serially mediated by reductions in total OSA-18 questionnaire score and VLF power. These preliminary findings are novel and provide a direction for future research to investigate the effects of VLF power-guided interventions on childhood OSA.

Pediatric pulmonary year in review 2021: Sleep medicine

Pediatric pulmonology publishes original research, review articles, and case reports on a wide variety of pediatric respiratory disorders. In this article, we summarized the past year's publications in sleep medicine and reviewed selected literature from other journals in this field. We focused on original research articles exploring aspects of sleep-disordered breathing in patients with underlying conditions such as cystic fibrosis, asthma, and sickle cell disease. We also explored sleep-disordered breathing risk factors, monitoring, diagnosis, and treatment; and included recent recommendations for drug-induced sleep endoscopy and ways to monitor and improve PAP adherence remotely.

Recent advances in paediatric sleep disordered breathing

This article reviews the latest evidence pertaining to childhood sleep disordered breathing (SDB), which is associated with negative neurobehavioural, cardiovascular and growth outcomes. Polysomnography is the accepted gold standard for diagnosing SDB but is expensive and limited to specialist centres. Simpler tests such as cardiorespiratory polygraphy and pulse oximetry are probably sufficient for diagnosing obstructive sleep apnoea (OSA) in typically developing children, and new data-processing techniques may improve their accuracy. Adenotonsillectomy is the first-line treatment for OSA, with recent evidence showing that intracapsular tonsillectomy results in lower rates of adverse events than traditional techniques. Anti-inflammatory medication and positive airway pressure respiratory support are not always suitable or successful, although weight loss and hypoglossal nerve stimulation may help in select comorbid conditions.

Educational aims

To understand the clinical impact of childhood sleep disordered breathing (SDB).To understand that, while sleep laboratory polysomnography has been the gold standard for diagnosis of SDB, other diagnostic techniques exist with their own benefits and limitations.To recognise that adenotonsillectomy and positive pressure respiratory support are the mainstays of treating childhood SDB, but different approaches may be indicated in certain patient groups.

Blood pressure variability in children with obesity and sleep-disordered breathing following positive airway pressure treatment

Obese youth with sleep-disordered breathing are treated with positive airway pressure to improve sleep and cardiovascular status. While improvements in sleep parameters have been confirmed, a study by Katz et al. showed no major improvement in ambulatory blood pressure. The aim of this ancillary study was to analyze short-term blood pressure variability, following positive airway pressure treatment, as a more sensitive marker of cardiovascular health. We analyzed 24-h blood pressure variability data in 17 children, taken at baseline and after 12 months of treatment. These data were derived from an already published prospective, multicenter cohort study conducted in 27 youth (8-16 years) with obesity who were prescribed 1-year of positive airway pressure for moderate-severe sleep-disordered breathing. Significant decreases were found in 24 h systolic blood pressure (p = 0.040) and nighttime diastolic blood pressure (p = 0.041) average real variability, and diastolic blood pressure (p = 0.035) weighted standard deviation. Significant decreases were noted in nighttime diastolic blood pressure time rate variability (p = 0.007). Positive airway pressure treatment resulted in a significant decrease in blood pressure variability, suggesting a clinically significant improvement of sympathetic nerve activity in youth with obesity and sleep-disordered breathing. IMPACT: Cardiovascular variability, as measured by blood pressure variability, is improved in children following positive airway pressure treatment. Our novel findings of improved blood pressure time rate variability are the first described in the pediatric literature. Future studies aimed at analyzing target organ damage in this patient population will allow for a better understanding as to whether alterations in blood pressure variability translate to decreasing target organ damage in children, as seen in adults.

Positive airway pressure for the treatment of the childhood obstructive sleep apnea syndrome

In this review, we have summarized the benefits of treatment with positive airway pressure for the childhood obstructive sleep apnea syndrome and presented a socio-ecological framework to enhance our understanding of positive airway pressure adherence predictors and important targets of comprehensive positive airway pressure treatment models across different pediatric populations. Although positive airway pressure is clearly a beneficial treatment for pediatric obstructive sleep apnea syndrome, additional research is needed to evaluate how socio-ecological factors may interact to predict positive airway pressure adherence, with more attention to the impact of the broader healthcare setting and on treatment approaches and outcomes in special pediatric populations.

Heart Rate Variability as a Potential Biomarker of Pediatric Obstructive Sleep Apnea Resolution

STUDY OBJECTIVES

Pediatric obstructive sleep apnea (OSA) affects cardiac autonomic regulation, altering heart rate variability (HRV). Although changes in classical HRV parameters occur after OSA treatment, they have not been evaluated as reporters of OSA resolution. Specific frequency bands (named BW1, BW2 and BWRes) have been recently identified in OSA. We hypothesized that changes with treatment in these spectral bands can reliably identify changes in OSA severity and reflect OSA resolution.

METHODS

404 OSA children (5-9.9 years) from the prospective Childhood Adenotonsillectomy Trial (CHAT) were included; 206 underwent early adenotonsillectomy (eAT), while 198 underwent watchful waiting with supportive care (WWSC). HRV changes from baseline to follow-up were computed for classical and OSA-related frequency bands. Causal mediation analysis was conducted to evaluate how treatment influences HRV through mediators such as OSA resolution and changes in disease severity. Disease resolution was initially assessed by considering only obstructive events, and was followed by adding central apneas to the analyses.

RESULTS

Treatment, regardless of eAT or WWSC, affects HRV activity, mainly in the specific frequency band BW2 (0.028-0.074 Hz). Furthermore, only changes in BW2 were specifically attributable to all OSA resolution mediators. HRV activity in BW2 also showed statistically significant differences between resolved and non-resolved OSA.

CONCLUSIONS

OSA treatment affects HRV activity in terms of change in severity and disease resolution, especially in OSA-related BW2 frequency band. This band allowed to differentiate HRV activity between children with and without resolution, so we propose BW2 as potential biomarker of pediatric OSA resolution.

The Different Facets of Heart Rate Variability in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), a heterogeneous and multifactorial sleep related breathing disorder with high prevalence, is a recognized risk factor for cardiovascular morbidity and mortality. Autonomic dysfunction leads to adverse cardiovascular outcomes in diverse pathways. Heart rate is a complex physiological process involving neurovisceral networks and relative regulatory mechanisms such as thermoregulation, renin-angiotensin-aldosterone mechanisms, and metabolic mechanisms. Heart rate variability (HRV) is considered as a reliable and non-invasive measure of autonomic modulation response and adaptation to endogenous and exogenous stimuli. HRV measures may add a new dimension to help understand the interplay between cardiac and nervous system involvement in OSA. The aim of this review is to introduce the various applications of HRV in different aspects of OSA to examine the impaired neuro-cardiac modulation. More specifically, the topics covered include: HRV time windows, sleep staging, arousal, sleepiness, hypoxia, mental illness, and mortality and morbidity. All of these aspects show pathways in the clinical implementation of HRV to screen, diagnose, classify, and predict patients as a reasonable and more convenient alternative to current measures.