Association between prenatal cadmium exposure and cord blood DNA methylation

Prenatal cadmium exposure is known to affect infant growth and organ development. Nonetheless, the role of DNA methylation in cadmium-related health effects has yet to be determined. To this end, we investigated the relationship between prenatal cadmium exposure and cord blood DNA methylation in Korean infants through an epigenome-wide association study. Cadmium concentrations in maternal blood during early and late pregnancy and in cord blood collected from newborns were measured using atomic adsorption spectrometry and DNA methylation analysis was conducted using HumanMethylationEPIC BeadChip kits. After adjusting for infant sex, maternal pregnancy body mass index, smoking status, and estimated leukocyte composition, we analyzed the association between CpG methylation and cadmium concentration in 364 samples. Among 835,252 CpG sites, maternal blood cadmium concentration in early pregnancy was significantly associated with two differentially methylated CpG sites, cg05537752 and cg24904393, which were annotated ATP9A and no gene, respectively. The study findings indicate that prenatal cadmium exposure is significantly associated with methylation statuses of several CpG sites and regions in Korean infants, especially during early pregnancy.