Abstract P168: Early Life Metal Profiles and Kidney Function in Mid-Adolescence: A Preliminary Study in Project Viva

Introduction: The developing kidney is vulnerable to pre- and postnatal environmental stressors. Suboptimal environmental conditions during early life, such as exposure to toxic metals and deficiency in essential metals, can alter the risk of kidney dysfunction later in life. In this pilot study, we aimed to examine the relationship between prenatal exposure to metals and adolescent kidney function using data from Project Viva, a Boston-area prospective pre-birth cohort. Hypothesis: Prenatal exposure to higher metal concentrations, both individually and as mixtures, will be associated with altered kidney function in mid-adolescence. Methods: We assessed the following metals in erythrocyte samples collected during pregnancy: 1 st -trimester [arsenic (As), barium (Ba), cadmium (Cd), cesium (Cs), mercury (Hg), lead (Pb), copper (Cu), magnesium (Mg), manganese (Mn), selenium (Se), and Zinc (Zn)]; 2 nd -trimester (Pb, Mn, Hg, and Se). We measured plasma cystatin C and creatinine from blood samples collected in mid-adolescence (mean age 18 years) in a sub-sample of Project Viva participants. We calculated the estimated glomerular filtrate rate (eGFR) using a cystatin C-based equation for children. We examined associations of prenatal metal exposure and mid-adolescent eGFR using linear regression for single metal analyses, and Bayesian kernel machine regression and quantile-based g-computation for mixture analyses. In all models, we adjusted for maternal education level, annual household income, race/ethnicity, child sex, and age at eGFR assessment. Results: A total of 146 participants had complete data for 1 st -trimester erythrocyte metals and mid-adolescent eGFR, and 105 participants had complete data for 2 nd -trimester blood metals and mid-adolescent eGFR. All children had eGFR values in the normal range (i.e., >60 mL/min/1.73m 2 ); the mean (SD) eGFR was 92.0 (13.7) mL/min/1.73m 2 . Most pairwise metal-eGFR relationships were statistically null; however, a 2-fold increase in 1 st -trimester Zn was associated with higher eGFR (β 7.25 mL/min/1.73m 2 ; 95% CI 0.33, 14.16), while a 2-fold increase in 2 nd -trimester Pb was associated with lower eGFR (β -4.90 mL/min/1.73m 2 ; 95% CI -8.32, -1.48). Mixture analyses did not identify statistically significant findings but suggested some non-linear associations and interactions between metals. Conclusions: Preliminary evidence suggests that prenatal Zn exposure is associated with higher kidney function while prenatal Pb exposure is associated with lower kidney function in mid-adolescence. We plan to assess eGFR in additional participants to increase the power of the analyses.