High respiratory sinus arrhythmia: A physiological marker of resilience against health problems associated with low socioeconomic status

• In Event: Adaptation, not deficit: Contextual and environmental influences of SES on neurodevelopment and self-regulation

Abstract

Low socioeconomic status (SES) during early life has been linked to poor health outcomes across the lifespan. Leading conceptual models propose that increased chronic stress exposure, associated with low SES environments, results in wear and tear on physiology and subsequently poorer health. Previous evidence suggests that high resting respiratory sinus arrhythmia (RSA), an index of parasympathetic nervous system activity, may promote resilience in the context of early life adversity by facilitating flexible physiological responding to threat. However,to our knowledge, no study has tested resting RSA as a moderator of the association between low SES and poor health in children. The current study tested resting RSA as a moderator of the relation between a multi-dimensional index of SES and two measures of physical health, in late childhood.

Methods. Participants included 180 children (51% male, 49% female; mean (SD) age = 9.9 (.57) years). SES was indexed as the average of standardized family yearly income, highest parental education level, and parent subjective social status. Parents reported on their child’s (1) global health impairment, and (2) sum of chronic health conditions, using the MacArthur Health and Behavior Questionnaire (HBQ). RSA was measured during a 5-minute seated resting period. A multiple linear regression, using robust estimation, was conducted to test the interaction between SES and RSA in relation to global health impairment. A generalized linear model with a Poisson distribution was utilized to test the interaction between SES and RSA in relation to the sum of chronic health conditions. Both models controlled for child age, sex, and body mass index (BMI).

Results. Significant interactions between SES and RSA were observed in predicting both child global health impairment (p = .002), and sum of chronic health conditions (p = .02). Johnson Neyman region of significance analysis revealed that lower SES was associated with poorer global health, but only for children with low to moderate RSA (i.e., values 0.2 SD above the mean and lower). Lower SES was also associated with greater number of chronic health conditions, but only for children with lower RSA (i.e., values 0.8 SD below the mean and lower). For children with higher RSA, the relations between SES and both health indices were nonsignificant. As expected, child BMI was correlated positively with both global health impairment (r = .15, p = .04) and number of chronic health conditions (r = .19, p = .01).

Discussion. High resting RSA may represent an important protective factor in the link between socioeconomic adversity and poor health. A better understanding of physiological mechanisms of risk and resilience in children may help improve targeted early intervention efforts.

Authors

• Nicholas Alen, University of California - Davis
  Presenting Author

• LillyBelle Ku'ulei Deer, University of Denver
  Non-Presenting Author

• Anna Parenteau, University of California - Davis
  Non-Presenting Author

• Camelia E Hostinar, University of California - Davis
  Non-Presenting Author