Prenatal Exposure to PM2.5 and Infant Autonomic Nervous System Reactivity: Effect Modification by Sex and Maternal Total Antioxidant Intake during Pregnancy

摘要

The autonomic nervous system (ANS) plays a key role in stress reactivity and is programmed during gestation. We investigated associations between prenatal exposure to fine particulate matter (PM2.5) and infant ANS reactivity during a stress challenge among 239 maternal-infant pairs enrolled in a Boston-based birth cohort. We estimated daily residential PM2.5 using satellite data in combination with land-use regression predictors. At 6 months, we measured parasympathetic nervous system (PNS) activity using continuous ECG and respiration monitoring during the repeated Still Face Paradigm (SFP-R), which is designed to elicit infant stress reactivity and regulation in response to maternal disengagement and interaction. We used multivariable linear regression to examine average PM2.5 exposure across pregnancy in relation to PNS withdrawal and activation, indexed by changes in respiratory sinus arrhythmia (RSA). We grouped infants by 'typical' or 'atypical' patterns of RSA change and used multivariable logistic regression to model associations between PM2.5 and group assignment. We examined interactions with sex and maternal total antioxidant intake during pregnancy, estimated using a food frequency questionnaire. We detected significant 3-way interactions (p<0.01 across models) between PM2.5, sex, and antioxidants. Among girls with low prenatal antioxidants (<50th percentile), each 10-unit increase in PM2.5 was associated with marginally reduced PNS withdrawal during stress (25% increase in RSA, p=0.06), marginally depressed PNS activation during recovery (24% decrease in RSA, p=0.05), and significantly increased odds of an 'atypical' response pattern (OR: 2.7, 95% CI: 1.2, 5.9). We did not observe significant findings among girls with higher prenatal antioxidants or among boys. Prenatal exposure to PM2.5 may disrupt programming of autonomic stress-response systems among girls. Higher intake of antioxidant-rich foods during pregnancy may protect against these effects.