Profiles of Multisystem Physiological Activity Across Early Childhood: Replicating Patterns and Exploring Associations

• In Event: A Multisystem Perspective for Understanding the Role of Physiological Regulation in Child Development

Abstract

Physiological regulation occurs across multiple collaborative systems, including the autonomic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. When examined singularly, research harnessing physiological indicators from each of these stress response systems has observed associations with a host of adaptive and maladaptive outcomes in childhood including behavior problems, attachment, and psychopathology (Bubier, Drabick, & Breiner, 2009; Bush & Boyce, 2016; Marshall & Fox, 2005). As understanding of individual physiological systems has increased and analytic techniques have advanced, researchers have begun to call for examinations of the synergistic (or antagonistic) nature of stress responsivity across multiple system (Bauer, Quas, & Boyce, 2002; Hostinar & Gunnar, 2013; McEwen, 2007). However, studies exploring multisystem regulation among youth are limited (see Ellis, Oldehinkel, & Nederhof, 2017; Roubinov, Boyce, Lee, & Bush, 2020 for notable exceptions), and even fewer have explored how early rearing experiences and behavioral outcomes are associated with multisystem activity.

The current study sought to replicate and extend previous findings from a study of multisystem physiology among kindergarten children (Roubinov et al., 2020). Our sample included 150 mother-child dyads (51.3% female; 32.7% African American) assessed at 18- and 36-months. We employed latent profile analysis to derive multisystem profiles based on children’s heart rate (HR), respiratory sinus arrhythmia (RSA), pre-ejection period (PEP), and cortisol measured during periods of rest and reactivity throughout a developmentally challenging protocol. Individual standardized residual reactivity scores for HR, RSA, and PEP were calculated as the mean reactivity across a series of challenge tasks regressed on the initial resting score. Cortisol reactivity was computed by regressing the post-protocol cortisol value on the pre-protocol value. Children were assigned to the most likely profile based on the estimated posterior probabilities for each profile. We then conducted multivariate analysis of variance (MANOVA) to compare the profiles on maternal perceived stress and socioemotional outcomes at 36-months (internalizing and externalizing symptoms).

At both 18- and 36 months, two distinct profiles emerged at both time points: one of generally moderate activity across all systems (Moderate Arousal) and one of heightened multisystem baseline activity (Anticipatory Arousal). Two profiles did not replicate over time: a profile of typically adaptive patterns across HR, RSA, PEP, and cortisol (Active Copers) and a profile of heightened HPA Axis activity (HPA Axis Responders) emerged at only 18- and 36-months, respectively. Importantly, the Anticipatory Arousal, Active Copers, and HPA axis Responders profiles were all markedly similar to those found in our prior study using an independent sample of older children (Roubinov et al., 2020). In the current study, consistent membership in the Anticipatory Arousal profile across time was associated with exposure to greater maternal stress at 18-months and internalizing problems at 36-months.

The current study replicates and extends prior findings to suggest early environmental exposures and behavioral outcomes are associated with multisystem activity. These findings elucidate potential developmental shifts in physiological organization and provide opportunities for future research to explore multisystem physiology as a mechanism between early adversity and later adjustment problems.

Authors

• Kristen L Rudd, University of California - San Francisco
  Presenting Author

• Nicole R Bush, University of California - San Francisco
  Non-Presenting Author

• Abbey Alkon, University of California - San Francisco
  Non-Presenting Author

• Danielle Roubinov, University of North Carolina at Chapel Hill
  Non-Presenting Author