REM-OSA vs NREM-OSA in Children: Separate Clinical Phenotypes or Markers of OSA Severity.

INTRODUCTION

Obstructive sleep apnea (OSA) occurs predominantly during REM sleep (REM-OSA) compared to NREM sleep (NREM-OSA) in both children and adults. However, it is not clear whether REM-OSA and NREM-OSA are separate clinical phenotypes of OSA or represent 2 ends of OSA severity spectrum.

OBJECTIVE

We aimed to compare clinical and polysomnography (PSG) characteristics of REM-OSA versus NREM-OSA in children, and to evaluate the effect of these characteristics on REM-related over NREM-related obstructive AHI ratio (REM-OAHI/NREM-OAHI).

METHODS

Clinical and PSG data of all children diagnosed with moderate to severe OSA by PSG between 2019 and 2024 were collected and analyzed. REM-OSA was defined as REM-OAHI/NREM-OAHI ratio of ≥2. NREM-OSA was defined as REM-OAHI/NREM-OAHI of < 2.

RESULTS

A total of 253 patients (169 male and 84 female) met the inclusion criteria. REM-OSA was identified in 174 (68.7%) patients, and NREM-OSA in 79 (31.2%) patients. There was no significant difference between REM-OSA and NREM OSA groups in gender, BMI, clinical diagnosis, symptoms or oxygenation indices. However, REM-OSA group had lower OAHI and less severe OSA than NREM-OSA group (p = 0.004, p = 0.003, respectively). Regression analysis showed that low OAHI was the only significant predictor of REM-OSA and the only predictor of high REM-AHI/NREM-AHI ratio, respectively (p = 0.001, p = 0.001).

CONCLUSION

REM-OSA and NREM-OSA are not likely to be separate clinical phenotypes of OSA but only markers of the disease severity, with NREM-OSA indicating more severe disease.