Associations Between Sleep and Trajectories of Respiratory Sinus Arrhythmia Responding in Children

• In Event: Poster Session 09
  In Poster Session: PS 09 Topic - Biological Processes: Psychophysiology

Abstract

Different patterns of parasympathetic nervous system (PNS) reactivity to stress can create vulnerability for various adverse outcomes in childhood, such as depression (Bosch et al., 2009) and externalizing problems (El-Sheikh & Hinnant, 2011). However, factors contributing to maladaptive response patterns have not been fully elucidated. Previous research indicates that sleep may be one such factor, as poorer sleep is associated with higher resting respiratory sinus arrythmia (RSA) for children (Elmore-Staton et al., 2012). However, this study did not examine children’s RSA during stress. To the best of our knowledge, no study has examined relations between sleep and changes in PNS activity during a stressor. Therefore, the current study investigates such changes; it is hypothesized that children’s worse objective and subjective measures of sleep will be associated with higher and more prolonged RSA responses during a mirror tracing task.
Data are from 199 children (Mage = 8.72 years; 77% white; 49% female) who completed a mirror tracing task while their RSA was monitored. Prior to the task, a three-minute baseline period was recorded. For baseline, participants were asked to sit quietly without any activity. To record RSA, electrodes were placed on the torso. RSA during the three-minute mirror tracing task was divided into 30-second segments and averaged for each segment. Participants wore an actigraph for seven nights and variables were averaged across the week: number of minutes slept, percent of minutes spent asleep (efficiency), and percent of minutes with physical activity. Participants also completed the School Sleep Habits Survey (SHSS; Wolfson & Carskadon, 1998) subscales for sleep/wake problems and daytime sleepiness.
Data were analyzed using multi-level modeling (level 1 = time segment; level 2 = participant). The dependent variable was RSA during the task. Based on results of unconditional models, cubic models of change were most appropriate. In conditional models, sleep variables and the interaction between these variables with the first, second, and third-order terms for time were included. Results of the five models are provided in Table 1. Child daytime sleepiness, sleep/wake problems, and sleep minutes were unrelated to trajectories of RSA during the mirror tracing task. However, sleep efficiency and activity were significantly associated with the intercept, linear, quadratic, and cubic terms of the trajectories of RSA. Trajectories of RSA during the task are plotted for -1 SD and +1 SD of efficiency (Figure 1A) and activity (Figure 1B). Participants with lower sleep activity and higher sleep efficiency had higher levels of RSA that increased more in response to the stressor initially but then declined similarly to participants with poorer sleep. However, at the end of the task, participants with lower sleep activity and higher sleep efficiency demonstrated slight increases in RSA while those with poor sleep continued to show declines in RSA. These findings suggest that childhood sleep difficulties may alter development of homeostatic regulatory mechanisms of the PNS, potentially leading to reduced reactivity to stress and less rapid recovery from stress.

Authors

• Grace Markowski, University of Kentucky
  Presenting Author

• Kyle Rawn, University of Kentucky
  Non-Presenting Author

• Peggy S Keller, University of Kentucky
  Non-Presenting Author