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

Comparison of sleep structure and clinical characteristics between REM-related OSA and non- REM-related OSA in children

OBJECTIVE

To measure the prevalence of REM-related OSA(rapid eye movement related obstructive sleep apnea) in children and describe and compare the demographics, clinical features, and sleep structure characteristics of REM-related OSA compared to non-REM-related OSA(no rapid eye movement related obstructive sleep apnea).

METHODS

Data were collected from 569 children at the Sleep Center of the Department of Otorhinolaryngology, Nanjing Children's Hospital. Physical examinations were performed, and all participants completed polysomnography (PSG) monitoring. Clinical characteristics and PSG data were compared between children with REM-related OSA and those with non-REM-related OSA.

RESULTS

The prevalence of REM-related OSA in children was 43.4 %. Children with REM-related OSA were more likely to be female compared to those with non-REM-related OSA (P = 0.015). N1(non-rapid eye movement sleep stage 1) sleep duration was shorter (P < 0.001), and SpO2 during REM periods was lower (P < 0.001) in REM-related OSA children compared to non-REM-related OSA children. The prevalence of P-OSA(positional obstructive sleep apnea)was higher in the REM-related OSA group. Female sex and P-OSA were identified as independent risk factors for REM-related OSA.

CONCLUSION

The prevalence of REM-related OSA was 43.4 %. Female sex and P-OSA are independent risk factors for REM-related OSA. These findings provide a basis for future personalized treatment strategies for OSA in children.

Adjusting the apnea-hypopnea index in children with a low percentage of REM sleep and its potential impact on OSA diagnosis and severity

STUDY OBJECTIVES

A decrease in rapid eye movement (REM) time during polysomnography in patients with obstructive sleep apnea (OSA) can result in underestimation of apnea-hypopnea index (AHI). We propose adjusting AHI to normalized REM% in individuals with REM% ≤ 15% to avoid underdiagnosis of OSA.

METHODS

All children who completed diagnostic polysomnography from 2016-2023 with REM% of ≤ 15% of total sleep time were selected for adjustment. AHI adjustment was done by multiplying AHI by a normalization factor (20%)/REM%. Changes in OSA diagnosis and severity were evaluated before vs after adjustment. Intraclass comparison and Bland-Altman plots were used to evaluate agreement level of adjusted AHI vs nonadjusted AHI with REM AHI as the reference. P value < .05 was significant.

RESULTS

Of 389 children reviewed, only 79 (20%) children had low REM% of ≤ 15%. Median (range) age was 12.8 (0.9-18) years with male/female ratio 2.3/1. Mean (standard deviation) sleep efficiency was 64.7% (12.3). Mean (standard deviation) REM% was 10.5% (3.4). Median AHI (range) before AHI adjustment was 1.7 (0-44) events/h vs 4.1 (0-74.4) events/h after AHI adjustment (P < .001). Adjusted AHI had better agreement with REM-AHI (intraclass correlation = .691; 95% confidence interval: 0.58, 0.80) than nonadjusted AHI (intraclass correlation = .485; 95% confidence interval: 0.39, 0.58). AHI adjustment changed diagnosis from normal to mild OSA in 12 (15%) patients, from mild to moderate OSA in 7 (9%) patients, and from moderate to severe OSA in 9 (11%) patients (P = .044).

CONCLUSIONS

Adjusting AHI in patients with low REM% to a normalized REM% can help avoid underdiagnosis of OSA and/or underestimation of its severity.

CITATION

Alnaimi A, Toma H, Abushahin A, Belavendra A, Abu-Hasan M. Adjusting the apnea-hypopnea index in children with a low percentage of REM sleep and its potential impact on OSA diagnosis and severity. J Clin Sleep Med. 2025;21(5):783-788.

Severe obstructive sleep apnea in children with syndromic craniosynostosis: analysis of pulse transit time

STUDY OBJECTIVES

We examined the association between pulse transit time (PTT) and obstructive sleep apnea (OSA) in children with syndromic craniosynostosis (SCS), where OSA is a common problem and may cause cardiorespiratory disturbance.

METHODS

A retrospective study of children (age < 18 years) with SCS and moderate-to-severe OSA (ie, obstructive apnea-hypopnea index ≥ 5) or no OSA (obstructive apnea-hypopnea index < 1) who underwent overnight polysomnography. Children without SCS and normal polysomnography were included as controls. Reference intervals for PTT were computed by nonparametric bootstrap analysis. Based on reference intervals of controls, the sensitivity and specificity of PTT to detect OSA were determined. In a linear mixed model, the explanatory variables assessed were sex, age, sleep stage, and time after obstructive events.

RESULTS

In all 68 included children (19 with SCS with OSA, 30 with SCS without OSA, 19 controls), obstructive events occurred throughout all sleep stages, most prominently during rapid eye movement (REM) sleep and non-REM sleep stages N1 and N2, with evident PTT changes. The greatest reductions were observed 4-8 seconds after an event (P < .05). In SCS with OSA, PTT reference intervals were lower during all sleep stages compared with SCS without OSA. The highest sensitivity was observed during N1 (55.5%), and the highest specificity during REM sleep (76.5%). The lowest PTT values were identified during N1.

CONCLUSIONS

Obstructive events occur throughout all sleep stages with transient reductions in PTT. However, PTT as a variable for OSA detection is limited by its sensitivity and specificity.

CITATION

Yang S, van Twist E, van Heesch GGM, et al. Severe obstructive sleep apnea in children with syndromic craniosynostosis: analysis of pulse transit time. J Clin Sleep Med. 2024;20(8):1233-1240.

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.

REM sleep obstructive sleep apnoea

Obstructive sleep apnoea (OSA) can occur in both rapid eye movement (REM) and non-REM sleep or be limited to REM sleep, when the upper airway is most prone to collapse due to REM sleep atonia. Respiratory events are usually longer and more desaturating in REM than in NREM sleep. The prevalence of REM OSA is higher in women than in men and REM OSA usually occurs in the context of mild-moderate OSA based on the apnoea-hypopnoea index calculated for the entire sleep study. Studies have highlighted some detrimental consequences of REM OSA; for example, its frequent association with systemic hypertension and a degree of excessive daytime sleepiness similar to that found in nonsleep-stage-dependent OSA. Moreover, REM OSA could increase cardiometabolic risk. Continuous positive airway pressure (CPAP) treatment aimed at preventing REM OSA should be longer than the 4 h usually considered as good compliance, since REM sleep occurs mostly during the second half of the night. Unfortunately, patients with REM OSA show poor adherence to CPAP. Alternative non-CPAP treatments might be a good choice for REM OSA, but data are lacking. This review summarises the available data on REM OSA and critically examines the weaknesses and strengths of existing literature.

REM-OSA as a Tool to Understand Both the Architecture of Sleep and Pathogenesis of Sleep Apnea-Literature Review

Sleep is a complex physiological state, which can be divided into the non-rapid eye movement (NREM) phase and the REM phase. Both have some unique features and functions. This difference is best visible in electroencephalography recordings, respiratory system activity, arousals, autonomic nervous system activity, or metabolism. Obstructive sleep apnea (OSA) is a common condition characterized by recurrent episodes of pauses in breathing during sleep caused by blockage of the upper airways. This common condition has multifactorial ethiopathogenesis (e.g., anatomical predisposition, sex, obesity, and age). Within this heterogenous syndrome, some distinctive phenotypes sharing similar clinical features can be recognized, one of them being REM sleep predominant OSA (REM-OSA). The aim of this review was to describe the pathomechanism of REM-OSA phenotype, its specific clinical presentation, and its consequences. Available data suggest that in this group of patients, the severity of specific cardiovascular and metabolic complications is increased. Due to the impact of apneas and hypopneas predominance during REM sleep, patients are more prone to develop hypertension or glucose metabolism impairment. Additionally, due to the specific function of REM sleep, which is predominantly fragmented in the REM-OSA, this group presents with decreased neurocognitive performance, reflected in memory deterioration, and mood changes including depression. REM-OSA clinical diagnosis and treatment can alleviate these outcomes, surpassing the traditional treatment and focusing on a more personalized approach, such as using longer therapy of continuous positive airway pressure or oral appliance use.

Neurocognitive, mood changes, and sleepiness in patients with REM-predominant obstructive sleep apnea

PURPOSE

This article focuses on recent evidence linking rapid eye movement (REM) obstructive sleep apnea (OSA) (REM-OSA) to neurocognitive dysfunction and mood changes; the proposed mechanisms for increased risk of neurocognitive dysfunction in REM-OSA, and future research prospects.

METHODS

PubMed and Google Scholar records were examined for articles utilizing pre-defined keywords. In this work, we mainly included studies published after 2017; nevertheless, critical studies published prior to 2017 were considered.

RESULTS

REM-OSA is an under-recognized stage-related sleep-disordered breathing in which obstructive respiratory events happen chiefly in stage REM. The disorder is commonly seen amongst younger patients and females and has recently been linked to cardiometabolic complications. Although less symptomatic than non-REM-OSA and non-stage-specific OSA, current findings indicate that REM-OSA may have neurocognitive repercussions and mood changes and could be linked to insomnia, increased dreams, and nightmares.

CONCLUSION

Currently available evidence indicates that REM-OSA may present with insomnia and nightmares and could affect cognitive function and mood.

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.