Maternal Dietary Glycemic Index and Glycemic Load in Pregnancy and Offspring Cord Blood DNA Methylation

Abstract Objective: Suboptimal nutrition in pregnancy is associated with worse offspring cardiometabolic health. DNA methylation may be an underlying mechanism. We meta-analyzed epigenome-wide association studies (EWASs) of maternal dietary glycemic index and load with cord blood DNA methylation. Research Design and Methods: We calculated maternal glycemic index and load from food frequency questionnaires, and ran EWASs on cord blood DNA methylation in 2003 mother-offspring pairs from three cohorts. Analyses were additionally stratified by maternal BMI categories. We looked-up the findings in EWASs of maternal glycemic traits and BMI, and in EWASs of birthweight and child BMI. We examined associations with gene expression in child blood in the online Human Early Life Exposome eQTM catalogue and in 223 adipose tissue samples. Results: Maternal glycemic index and load were associated with cord blood DNA methylation at 41 cytosine-phosphate-guanine sites (CpGs, P