Cardiac Autonomic Modulation and Sleep-Disordered Breathing in Children

A game-based learning approach to sleep hygiene education: a pilot investigation

Introduction

Sleep hygiene education (SHE) consists of environmental and behavioral practices primarily intended to reduce sleep problems. Currently considered ineffective as a stand-alone treatment, the manner in which the education is typically delivered may be ineffective for the acquisition of new knowledge. The purpose of this study was to determine if a more engaging teaching medium may improve the efficacy of sleep hygiene education. This study examined the use of game-based learning to teach SHE to individuals with sleep problems.

Methods

35 participants played the SHE games for 30 days. Differences in pre- and post-state anxiety and sleep quality measures were examined.

Results

Participants had significant improvements in sleep quality and state anxiety after using the app for 30 days, although scores for the majority of patients remained elevated.

Discussion

This pilot investigation provides initial evidence for the efficacy of a game-based approach to SHE.

Obesity is associated with impaired cardiac autonomic modulation in children

OBJECTIVE

To examine the cross-sectional association between measurements of obesity and subclinical impairment of cardiac autonomic modulation (CAM) in a population-based sample of children.

METHODS

Data from 616 grade K-5 children randomly selected from Central Pennsylvania were utilized. Obesity was defined using the International Obesity Task Force (IOTF) age- and sex-specific cut-off criteria and classified as normal weight, overweight, and obese. CAM was measured by heart rate variability (HRV) analysis of beat-to-beat RR intervals, including time domain measures i.e., the standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of squares of differences between adjacent RR intervals (RMSSD), and mean heart rate (HR); and frequency domain measures i.e., high frequency power (HF), low frequency power (LF), and LF/HF ratio.

RESULTS

The prevalence of obesity and overweight in children was 12.3%, and 16.5%, respectively. Age, race, sex, and sleep disorder breathing (SDB) adjusted means (standard error, SE) of SDNN were 98 (1.24), 90.2 (2.58), and 81.9 (3.03) milliseconds (ms) in normal weight, overweight, and obese groups, respectively; and that for (log) HF were 6.83 (0.04), 6.56 (0.08), and 6.35 (0.09) ms(2), respectively. Comparing the magnitude of effects from body mass index (BMI), weight, and height percentiles, and waist circumference on HRV indices revealed that body weight was the strongest correlate of HRV indices.

CONCLUSION

Childhood obesity is significantly associated with lower HRV, indicative of sympathetic overflow unopposed by parasympathetic modulation. These findings support the need to target childhood-obesity before traditional "high risk age" for cardiac events.

Sleep-disordered breathing in children is associated with impairment of sleep stage-specific shift of cardiac autonomic modulation

We examined the effects of sleep stages and sleep-disordered breathing (SDB) on autonomic modulation in 700 children. Apnea hypopnea index (AHI) during one 9 h night-time polysomnography was used to define SDB. Sleep stage-specific autonomic modulation was measured by heart rate variability (HRV) analysis of the first available 5 min RR intervals from each sleep stage. The mean [standard deviation (SD)] age was 112 (21) months (49% male and 25% non-Caucasian). The average AHI was 0.79 (SD = 1.03) h(-1), while 73.0%, 25.8% and 1.2% of children had AHI <1 (no SDB), 1-5 (mild SDB) and >or=5 (moderate SDB), respectively. In the no SDB group, the high frequency (HF) and root mean square SD (RMSSD) increased significantly from wake to Stage 2 and slow wave sleep (SWS), and then decreased dramatically when shifting into rapid eye movement (REM) sleep. In the moderate SDB group, the pattern of HRV shift was similar to that of no SDB. However, the decreases in HF and RMSSD from SWS to REM were more pronounced in moderate SDB children [between-group differences in HF (-24% in moderate SDB versus -10% in no SDB) and RMSSD (-27% versus -12%) were significant (P < 0.05)]. The REM stage HF is significantly lower in the moderate SDB group compared to the no SDB group [mean (standard error): 4.49 (0.43) versus 5.80 (0.05) ms(2), respectively, P < 0.05]. Conclusions are that autonomic modulation shifts significantly towards higher parasympathetic modulation from wake to non-rapid eye movement sleep, and reverses to a less parasympathetic modulation during REM sleep. However, the autonomic modulation is impaired among children with moderate SDB in the directions of more reduction in parasympathetic modulation from SWS to REM sleep and significantly weaker parasympathetic modulation in REM sleep, which may lead to higher arrhythmia vulnerability, especially during REM sleep.