Objectives:
To investigate the relationship between sleep disordered breathing (SDB) and cardiac autonomic modulation (CAM) in a population-based sample of adolescents.
Methods:
We used available data from 400 adolescents who completed the follow up examinations in the population-based PSCC study. 1-night polysomnography was used to assess apnea hypopnea index (AHI). AHI was used to define no-SDB (AHI<1), mild SDB (1≤AHI<5), and moderate SDB (AHI≥5). CAM was assessed by heart rate variability (HRV) analysis of beat-to-beat normal R-R intervals from a 39-hour high resolution Holter ECG. The HRV indices in frequency domain [high frequency power (HF), low frequency power (LF), and LF/HF ratio] and time domain [standard deviation of normal RR intervals (SDNN), and the square root of the mean squared difference of successive normal RR intervals (RMSSD), and heart rate (HR)] were calculated on a 30-minute basis (78 repeated measures). Mixed-effects models were used to assess the SDB and HRV relationship.
Results:
The mean age was 16.9 yrs (SD=2.19), with 54% male and 77% white. The mean (SD) AHI were 0.52 (0.26), 2.38 (1.03), and 12.27 (14.54) for no-, mild-, and moderate-SDB participants. The age, race, sex, and BMI percentile adjusted mean (SE) HRV indices across three SDB groups are presented in Table 1. In summary, sleep disordered breathing was associated with lower HRV and higher HR in this population-based adolescent sample, with a significant dose-response relationship.
Conclusion:
moderate SDB in adolescents is already associated with lower HRV, indicative of sympathetic activation and lower parasympathetic modulation, which has been associated with cardiac events in adults.
Sleep disordered breathing in children disrupts the maturation of autonomic control of heart rate and its association with cerebral oxygenation
