Student and Research Assistant Brown University Los Altos , California, United States
Background: Children exposed to early adversity (socioeconomic, psychosocial, and medical risk factors) are at increased risk for negative health and behavioral outcomes. Early adversity “gets under the skin” via excessive and/or prolonged exposure to physiological stress which can result in hyperactivation and “wear and tear” on the hypothalamic-pituitary-adrenal (HPA) axis, thought of as “allostatic load.” HPA dysregulation can disrupt the release of cortisol, a well-studied stress hormone. Hair cortisol and cortisone (HCC) are promising biomarkers of long-term stress accumulation.
Due to their heightened medical problems, exposure to the stresses of prematurity, and need for neonatal intensive care, very preterm infants are at increased risk of HPA dysregulation and downstream behavioral problems. Links between early adversity, biomarkers of stress accumulation, and behavioral problems have not been investigated in this high-risk population. Objective: To assess associations between early adversity, HCC, and internalizing/externalizing problems in children born very preterm. Design/Methods: Our cohort includes 456 infants born < 30 weeks gestation from the multi-site Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) study. A cumulative early adversity index was constructed with 46 pre-, peri-, and postnatal risk factors (demographic, medical, psychological, and social risk variables) collected from birth to age 4 years. Hair samples were collected from the proximal crown area at age 4 follow-up visits and analyzed using liquid chromatography-tandem mass spectrometry to quantify HCC. Parents reported child internalizing/externalizing symptoms using the Behavior Assessment System for Children (3rd edition) at age 5. Multivariable regression and mediation will test the following hypotheses: (1) greater early adversity and greater HCC will be related to elevated child behavior problems at age 5 and (2) HCC will mediate associations between early adversity and child behavior problems. IRB approval has been obtained. Data analysis will be completed by January 2024.
