Urine Metabolism Biomarkers Predict Preterm Infant Adiposity at Hospital Discharge

In infants born to women with diabetes (DM), this study explores associations of urinary metabolite patterns with adiposity development in the newborn period. In term and preterm (30-36 weeks gestational age) infants, body composition assessments were completed at hospital discharge. In urine samples from the first week, a targeted metabolomics assay was used. Quantile regression was used to evaluate associations of metabolite groups with DM in pregnancy and infant adiposity. Among 91 infants, 25 (27%) were exposed to DM, 68 (75%) were preterm. In the factor analysis, there was an association between factor 4 score (fatty acid and amino acid metabolites) and triceps skin fold thickness (β = 1.67 [95%CI: 0.62, 2.72]) and mid arm circumference (β = 1.59 [95%CI: 0.70, 2.49]) in preterm-DM group. Urinary C2, C3, and ornithine were decreased in DM-group (fold change <0.67, p < 0.01), and urinary C0, C2, C3, C5, ornithine, proline, and lysine were increased in preterm group (fold-change >2.7, p<0.0001). In this cohort, infant urinary amino acid and acylcarnitine concentrations varied by DM during pregnancy and gestational age and were differentially related to postnatal adiposity in preterm DM-group. Unique signatures of urinary metabolites may reflect early metabolism changes in the developing infant.