Poster #19 - Autonomic Nervous System Reactivity in Early Childhood: Stability Over Time and Relations to Demographic Characteristics

• In Event: 2-055 - Poster Session 06
  In Poster Session: PS 06 Section - Biological Processes: Psychophysiology

Integrative Statement

Cardiac measurements of the autonomic nervous system (ANS), respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), are highly responsive and sensitive to environmental changes that elucidate the individual’s unique stress response (Alkon et al., 2003; Berntson, Quigley, & Lozano, 2007). There are few studies that explore the stability of ANS reactivity in early childhood. A secondary analysis of a cohort study of 162 children of low socio-economic, obese or overweight mothers in the Stress, Eating, and Early Development (SEED) Study was conducted to 1) describe the reactivity frequencies at 6 and 18 months of age, 2) identify the frequency of stability of RSA and PEP reactivity from 6 to 18 months, and 3) determine the relationship between children’s sex, ethnicity, and household income and their stress reactivity at 6 and 18 months. The children’s mothers self-reported children’s sex, ethnicity, and household income. At 6 months, a standard Still Face Paradigm (SFP) consisting of three, 2-minute episodes (play, Still Face (SF), and play) was administered while continuously monitoring cardiac measures of the ANS. RSA and PEP reactivity were calculated using the last SF the child completed minus the first play episode. At 18 months, a developmental challenge protocol (DCP) was administered consisting of three developmental challenges and two resting episodes. RSA and PEP reactivity were calculated by the mean challenge response across the three tasks minus the first resting episode. Reactive was defined as a negative reactivity score and stability was defined as the same reactive profile at 6 and 18 months among children who completed both the SFP and DCP. Of the 162 children, 85 (52.5%) were girls and 65 (40.1%) are Hispanic/Latino. The median household income was $20,500 (n=139). At 6 months, the mean (SD) of RSA reactivity was -0.79 (1.27) and PEP reactivity was -1.33 (3.45). At 18 months, the mean (SD) of RSA reactivity was 0.25 (0.74) and PEP reactivity was 0.58 (2.23). At 6 months, 70% of the children had RSA reactivity and 61% had PEP reactivity compared to 37% and 38% respectively at 18 months (Table 1). The number of children with RSA and PEP reactivity was statistically significantly different from 6 to 18 months (Table 2). Forty-five percent of the children showed stability in their RSA reactivity (n=29) and 37% in their PEP reactivity (n=19) from 6 to 18 months. The child's sex, ethnicity, and household income were not significantly associated with RSA or PEP reactivity at 6 or 18 months. The SFP at 6 months provoked a larger RSA and PEP response than the DCP at 18 months. Children’s individual differences elucidated through ANS reactivity shows stability over time while others have unstable ANS reactivity over time. Future studies should explore the ANS response based on the context of the challenge and how the type of challenge may affect the stability of ANS reactivity. Our future analyses will include ANS reactivity at 36 months of age to assess stability over three timepoints.

Authors

• Michelle Stephens, University of California, San Francisco (UCSF) School of Nursing
  Presenting Author

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

• Karen Jones-Mason, University of California, San Francisco; Department of Psychiatry, Center for Health and Community
  Non-Presenting Author

• Nicole R. Bush, University of California, San Francisco (UCSF), Departments of Psychiatry and Pediatrics
  Non-Presenting Author