# Urine Metabolism Biomarkers Predict Preterm Infant Adiposity at Hospital Discharge

## TL;DR

Urine metabolites in preterm infants born to mothers with diabetes are linked to body fat at hospital discharge.

## Contribution

The study identifies specific urinary metabolite patterns associated with postnatal adiposity in preterm infants exposed to maternal diabetes.

## Key findings

- Factor 4 score (fatty acid and amino acid metabolites) was associated with increased triceps skin fold and mid arm circumference in preterm infants of mothers with diabetes.
- Urinary C2, C3, and ornithine were decreased in the diabetes-exposed group.
- Urinary C0, C2, C3, C5, ornithine, proline, and lysine were increased in preterm infants.

## Abstract

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.

In this cohort of term and preterm infants, urinary amino acid and acylcarnitine concentrations varied by diabetes in pregnancy exposure and gestational age at birth, and certain patterns of urinary metabolites were differentially related to postnatal adiposity development in preterm infants of women with diabetes in pregnancy.