The effect of childhood obstructive sleep apnea on ambulatory blood pressure is modulated by the distribution of respiratory events during rapid eye movement and nonrapid eye movement sleep

Does REM AHI Predict Persistent OSA After Pediatric Adenotonsillectomy?

OBJECTIVE

The utility of REM AHI in managing pediatric obstructive sleep apnea (OSA) is not fully understood. This study aimed to evaluate the relationship of preoperative REM AHI to postoperative persistence of OSA in children who underwent adenotonsillectomy.

METHODS

This retrospective chart review identified children under the age of 18 years that received an adenotonsillectomy for OSA and a preoperative and postoperative polysomnogram. Children with craniofacial or neuromuscular disorders or a tracheostomy were excluded. The primary outcome was the postoperative persistence of OSA, defined as a postoperative obstructive apnea-hypopnea index (oAHI) ≥ 1.5 events/hour. REM-predominant OSA was defined as a ratio of REM/NREM AHI ≥ 2. REM AHI minus NREM AHI and REM AHI minus oAHI helped to identify patients with a larger distribution of REM AHI.

RESULTS

A total of 353 patients were included. Postoperative persistent OSA was seen in 232 (65.7%) children. The preoperative REM AHI, REM AHI minus NREM AHI, and REM AHI minus oAHI of children with persistent OSA did not differ significantly from children with resolution of OSA. Rates of persistence were not different between those with REM-predominant OSA and REM-independent OSA (63.8% vs 70.7%, P = .218).

CONCLUSION

This study suggests that preoperative REM AHI may be a poor predictor of OSA persistence after adenotonsillectomy. Further study is needed to help characterize how pre-operative REM AHI should impact clinicians' decision making, family counseling and recommendations.

Impaired declarative memory consolidation in children with REM sleep-related obstructive sleep apnea

STUDY OBJECTIVES

We explored whether declarative memory consolidation is impaired in children with rapid eye movement sleep-related obstructive sleep apnea (REM-OSA) and investigated the correlation between memory consolidation and sleep-related respiratory parameters.

METHODS

Participants were children with habitual snoring aged 6-14 years and control children. Participants underwent polysomnography and declarative memory testing. Participants with snoring were categorized as primary snoring (PS), non-rapid eye movement sleep-related obstructive sleep apnea (NREM-OSA), stage-independent (SI)-OSA, and REM-OSA according to obstructive apnea-hypopnea index (OAHI), OAHI in REM sleep (OAHIREM), and OAHI in NREM sleep (OAHINREM). Declarative memory consolidation level was assessed by recall and recognition rates.

RESULTS

There were 34 controls and 228 children with sleep-disordered breathing: 73 PS, 48 NREM-OSA, 59 SI-OSA, and 48 REM-OSA. Total arousal index was lower in the REM-OSA group than in the NREM-OSA group. In all groups, retest scores were higher than immediate test scores. Recall consolidation in PS, SI-OSA, and REM-OSA groups was lower than for controls and lower in REM-OSA than in NREM-OSA. There were no correlations between recall consolidation or recognition consolidation and OAHI, OAHINREM, oxygen desaturation index in REM sleep, total arousal index, or REM sleep percent. Recognition consolidation was negatively correlated with OAHIREM.

CONCLUSIONS

Memory consolidation is impaired in children with REM-OSA compared with NREM-OSA and controls. There was no significant correlation between memory consolidation and OAHI, and recognition consolidation was negatively correlated with OAHIREM. It is important to pay attention to the OSA subtype in children.

CITATION

Tang Y, Yang C, Wang C, Wu Y, Xu Z, Ni X. Impaired declarative memory consolidation in children with REM sleep-related obstructive sleep apnea. J Clin Sleep Med. 2024;20(3):417-425.

Prevalence and Risk Factors for Rapid Eye Movement-Related Obstructive Sleep Apnea in Children

OBJECTIVES

Different pathophysiological mechanisms and the distribution of respiratory events among rapid eye movement (REM) and non-rapid eye movement (NREM) sleep modulate the effect of obstructive sleep apnea (OSA). We aimed to study the prevalence and risk factors for REM-related OSA in children.

STUDY DESIGN

Retrospective, cross-sectional study.

METHODS

We recruited 366 children with OSA confirmed by polysomnography (PSG) over a 5-year period. REM-related OSA is defined by an obstructive apnea-hypopnea index (OAHI) in the REM sleep ≥2× than during NREM sleep.

RESULTS

The prevalence of REM-related OSA in children was 50.3%. Children with REM-related OSA were more likely to be female (P = 0.042), and had lower prevalence of adenotonsillar hypertrophy (P = 0.043) compared with children with other OSA subtypes. Children with REM-related OSA slept longer in the supine position (P = 0.003), had shorter duration of NREM1 sleep (P = 0.018), lower nadir SpO2 (P = 0.005), and a higher oxygen desaturation index 3% (ODI3%) (P = 0.014), and lower arousal index (P = 0.034) compared with other OSA subtypes. Female gender and supine sleep was the independent risk factors for REM-related OSA.

CONCLUSION

The prevalence of REM-related OSA was 50.3%. OAHIREM should be considered as an important parameter in future clinical research studies done in children with OSA.

Natural History of REM-OSA in Children and Its Associations with Adverse Blood Pressure Outcomes: A Longitudinal Follow-Up Study

PURPOSE

Most respiratory events in childhood obstructive sleep apnea (OSA) take place during rapid-eye-movement (REM) sleep. This study aimed to describe the characteristics and natural history of childhood REM-OSA and to evaluate the associations between OSA subtypes and blood pressure (BP) outcomes.

PARTICIPANTS AND METHODS

This was a prospective 10-year follow-up study of a cohort established for a childhood OSA epidemiologic study. All subjects from the original cohort were invited to undergo a polysomnography (PSG) and 24-hour ambulatory blood pressure (ABP) monitoring. REM-OSA was defined with a ratio of obstructive apnea hypopnea index (OAHI) during REM sleep (OAHI_REM) to OAHI during non-REM sleep (OAHI_NREM) ≥ 2. Natural history was observed and linear mixed models were used to assess the associations between OSA subtypes and BP outcomes.

RESULTS

A total of 610 participants from baseline were included to study the epidemiology of REM-OSA in childhood. Among children with OSA, 65% had REM-OSA. At 10-year follow-up, 234 were included in the analysis. REM-OSA was more common at both baseline (58/92, 63%) and 10-year follow-up (34/58, 59%). For those with REM-OSA at baseline and persistent OSA at follow-up, the majority (72%) remained to have REM-OSA. Compared to those without OSA, subjects with REM-OSA had significantly higher nocturnal SBP (mean difference 2.19 mmHg, 95% confidence interval (CI): 0.12, 4.26; p = 0.039) and DBP (mean difference 1.58 mmHg, 95% confidence interval (CI): 0.11, 3.04; p = 0.035), and less nocturnal SBP dipping (mean difference -1.84%, 95% CI: -3.25, -0.43; p = 0.011), after adjusting for potential confounders. This significant association between REM-OSA and nocturnal SBP dipping was observed at baseline visit only.

CONCLUSION

REM-OSA was found to be a stable phenotype through childhood to young adulthood, and REM-OSA was associated with higher nocturnal BP and a lesser degree of nocturnal SBP dipping in children.

Volume estimation of tonsil phantoms using an oral camera with 3D imaging

Three-dimensional (3D) visualization of oral cavity and oropharyngeal anatomy may play an important role in the evaluation for obstructive sleep apnea (OSA). Although computed tomography (CT) and magnetic resonance (MRI) imaging are capable of providing 3D anatomical descriptions, this type of technology is not readily available in a clinic setting. Current imaging of the oropharynx is performed using a light source and tongue depressors. For better assessment of the inferior pole of the tonsils and tongue base flexible laryngoscopes are required which only provide a two dimensional (2D) rendering. As a result, clinical diagnosis is generally subjective in tonsillar hypertrophy where current physical examination has limitations. In this report, we designed a hand held portable oral camera with 3D imaging capability to reconstruct the anatomy of the oropharynx in tonsillar hypertrophy where the tonsils get enlarged and can lead to increased airway resistance. We were able to precisely reconstruct the 3D shape of the tonsils and from that estimate airway obstruction percentage and volume of the tonsils in 3D printed realistic models. Our results correlate well with Brodsky's classification of tonsillar hypertrophy as well as intraoperative volume estimations.