Shallower sleep and increased cortical arousability among adolescents in-school were associated with lower nighttime Log-LF (p<0.001) and SDNN (p=0.003) and higher HR (p=0.008).
Cohort (n=344)
Shallow sleep and high cortical arousability are associated with impaired cardiac autonomic modulation in adolescents, particularly when entrained to academic school schedules.
Abstract Introduction Prior studies in adolescents show that the odds ratio product (ORP), an EEG measure of sleep depth, and ORP-9, an EEG measure of cortical arousability, are associated with heart rate variability (HRV), an EKG measure of cardiac autonomic modulation (CAM). Specifically, higher ORP (i.e., shallower sleep) and ORP-9 (i.e., increased cortical arousability) are both associated with decreased low-frequency HR oscillations (Log-LF) and decreased standard deviation between normal sinus rhythms (SDNN), indicating increased risk of developing cardiovascular disease. These associations have not been evaluated in the natural context of adolescents having to entrain to the academic school schedule (i.e., in-school) or during free vacation days (i.e., on-break). Methods We studied 344 adolescents from the Penn State Child Cohort (median 16 years; 47% female; 23% racial/ethnic minority), of whom 215 were evaluated while in-school. We extracted ORP and ORP-9 during NREM sleep from 9-hour, in-lab polysomnography (PSG) and Log-LF and SDNN from Holter EKG monitoring during the 24 hours after PSG. Linear regression models examined the associations of ORP and ORP-9 with 24-hour HRV indices stratified by whether the participant was evaluated while in-school or on-break. Covariables included sex, race/ethnicity, age, BMI percentile, metabolic syndrome, insomnia symptoms, PSG-measured sleep apnea, and actigraphy-measured sleep duration. Results Amongst adolescents evaluated while in-school, higher ORP was associated with lower Log-LF and SDNN as well as higher HR during the daytime (Log-LF: p=0.017; SDNN: p=0.010; HR: p=0.012) and nighttime (Log-LF: p 0.001; SDNN: p=0.003; HR: p=0.008). Higher ORP-9 was associated with the same HRV indices and HR during the daytime (Log-LF: p=0.005; SDNN: p=0.003; HR: p=0.022) and nighttime (Log-LF: p=0.006; SDNN: p=0.007; HR: p=0.021) amongst adolescents evaluated while in-school. No significant associations were found among adolescents evaluated while on-break (all p’s0.10). Conclusion Shallow sleep and high cortical arousability contribute to impaired CAM most when adolescents are in school. These findings highlight the importance of the context in which an adolescent is assessed and its impact on the associations between the sleeping brain and cardiac health. Support (if any) R01HL136587, R01MH118308
Rahawi et al. (2026) conducted a cohort in Cardiac autonomic modulation in adolescents (n=344). In-school schedule vs. On-break schedule was evaluated on 24-hour HRV indices (Log-LF and SDNN) and HR. Shallower sleep and increased cortical arousability among adolescents in-school were associated with lower nighttime Log-LF (p<0.001) and SDNN (p=0.003) and higher HR (p=0.008).