Sever O, et al. - In this cross-sectional study, researchers assessed the links between the percentage of rapid eye movement (REM%) sleep, body mass index (BMI) z-score, and obstructive sleep apnea (OSA) severity in overweight and obese adolescents. Study participants included 92 (43% female) overweight and obese individuals aged 13–17 years who had overnight polysomnography (PSG) at Children’s Hospital Los Angeles between 2010 and 2017. The investigators recorded 2.27 ± 0.47 as average BMI z-score, with 71% having BMI z-score ≥ 2. REM% during PSG and obstructive apnea-hypopnea index were 15.6 ± 6.8 and 17.1 ± 24.3, respectively. They noted an association of BMI z-score with decreased REM% in severe OSA and unexpectedly increased REM% in mild OSA among overweight and obese adolescents; however, no association was evident in no OSA or OSA of moderate severity.