Reduction in Parasympathetic Tone During Sleep in Children With Habitual Snoring

Abstract

Introduction: Changes in the autonomic nervous system due to Obstructive Sleep Apnea (OSA) during the life span have been described. Some pediatric studies have shown cardiovascular effects in children who do not fit the criteria for OSA; namely children with mild sleep disordered breathing.Objective: We investigated heart rate variability (HRV) during sleep in children with chronic snoring and flow limitation events during sleep.Methods: Ten children and adolescents with chronic snoring and an apnea hypopnea index < 1, associated to high Respiratory Index, and 10 controls matched for age, gender, and Tanner stage were monitored following one night of habituation in the sleep laboratory. HRV was studied at each sleep stage. The time and frequency domains were calculated for each 5-min period.Results: All patients were chronic heavy snorers. They presented an apnea hypopnea index = 0.8, respiratory disturbance index = 10.2/h with lowest O2 saturation 96.1 ± 2.4%. The total power of HRV was decreased in all stages (p < 0.05). There was also a decrease in NN50 and pNN50 during all sleep stages compared to healthy controls (p = 0.0003 and p = 0.03, respectively).Conclusion: A reduction in parasympathetic tone was found in the patient group. This may represent an autonomic impairment during sleep in children with mild SDB. A reduction in HRV in children with habitual snoring could be associated with possible increases in cardiovascular risk in adulthood.Significance: The study indicates that children with habitual snoring have important parasympathetic tone changes during sleep.

Cross‐sectional case‐control study of the relationships between pharyngeal compliance and heart rate variability indices in childhood obstructive sleep apnoea

“…et al, 2016), the modifications observed in patients with OSA could be at least partially protective (blunted increase in parasympathetic activity) or could reflect a lack of adaptability of the autonomic nervous system and hence an incapability to restore homeostasis after an apnoeic episode (Milagro et al, 2019). We observed a negative correlation between AHI and parasympathetic activity in REM sleep, as previously shown (Lopes et al, 2018).…”

“…First of all, our present children without OSA were not healthy, as almost all were snorers. Along this line, Lopes et al showed that children with habitual snoring have a reduction in parasympathetic tone during sleep as compared to healthy children (Lopes et al, 2018). Whether primary snoring is associated with modified HRV remains debated (Nisbet et al, 2014).…”

The Inconsistent Nature of Heart Rate Variability During Sleep in Normal Children and Adolescents

“…Many HRV studies in sleeping children assess the relationship between age and heart rate variability to measure the "maturation of the autonomic capacity" (56)(57)(58) or to determine HRV differences in children with disorders affecting cardiac function such as sleep disordered breathing (59). These studies all yield different information as the protocol of when to measure HRV at night are not consistent and most amalgamate and average data from like stages across the night.…”

Cardiac autonomic control during non‐REM and REM sleep stages in paediatric patients with Prader‐Willi syndrome

“…To compare HRV analyses during different sleep stages (stages N2, slow‐wave sleep [SWS] and REM), an average of the first two consecutive 5‐min periods of uninterrupted specific sleep stages without significant apnea/hypopnea or arousal events were selected, as previously used (Lopes, Spruyt, Azevedo‐Soster, Rosa, & Guilleminault, 2018). Concerning time‐domain analysis, five indices were derived from the normal‐to‐normal R‐R interval (NN): standard deviation of all NN intervals (SDNN ms); the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD ms); standard deviation of differences between adjacent NN intervals (SDSD ms); number of adjacent NN intervals differing by >50 ms (NN50); and the proportion of adjacent NN intervals differing by >50 ms (pNN50%).…”