674 - Bioactive components in human milk differ with obesity and diabetes in pregnancy

Publication Number: 674.3796

Catherine O. Buck, Yale School of Medicine, Guilford, CT, United States; Clare Keeney, Frank H. Netter MD School of Medicine at Quinnipiac University, North Haven, CT, United States; Meaghan Molloy, Yale-New Haven Children's Hospital, Middletown, CT, United States; Veronika Shabanova, Yale School of Medicine, New Haven, CT, United States; Bridget Young, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States; Laura D. Brown, University Of Colorado Anschutz Medical Campus, Aurora, CO, United States; Sarah Taylor, Yale School of Medicine, New Haven, CT, United States

Background: Human milk contains bioactive components which support infant growth. Examining how human bioactive components are impacted by metabolic health in pregnancy may elucidate the mechanisms of adverse infant growth outcomes after exposure to diabetes (DM) and obesity (OB) in pregnancy.

Objective: To examine the influence of OB and DM in pregnancy on human milk bioactive components such as energy metabolism hormones and free amino acids (FAA) concentrations.

Design/Methods: In a prospective cohort study, term (> 37 weeks) and preterm (30 to 36 weeks) infants and their mothers were enrolled during the birth hospitalization. In milk samples (1 sample per subject) collected between 1-11 days postpartum, we measured leptin, adiponectin, and insulin (enzyme-linked immunosorbent assays) and FAA (high-performance liquid chromatography) concentrations. Variation in these concentrations across the day of sample collection were descriptively visually summarized, and quantile regression was used to evaluate average between-group median differences in the milk components by DM and OB exposure.

Results: Among 150 infants in the initial cohort, 49 with human milk samples available for analysis were included. A total of 17 (35%), 24 (50%), 33 (69%) subjects were in the DM, OB, and preterm groups, respectively. Median gestational age was 35 weeks, and most infants required neonatal intensive care unit admission (N=44, 92%), but there were not meaningful differences in other characteristics by DM or OB exposure in the sample (Table 1). Median postnatal day of milk collection was 3.2 days, which was not different across OB or DM groups. Adiponectin and most FAA concentrations decreased with increasing postnatal day of sample collection (Figure 1). Concentrations of insulin, aspartic acid, citrulline, phenylalanine, phosphoserine, and tyrosine were higher in the DM group vs non-DM group, and leptin was higher in OB-group vs non-OB group (Table 2).

Conclusion(s): In this cohort of infants with high proportion of OB and DM exposure in pregnancy, there were different profiles of FAA and energy metabolism hormones across OB and DM exposure groups. Across all samples, adiponectin and most FAA in human milk decreased over the first weeks. This analysis, especially with the inclusion of preterm infants, provides direction for further studies to examine how DM and OB exposure impact milk composition and subsequent infant growth and development.

Figure 1: Observed change in human milk bioactive substance concentrations by age of milk sample collection, including (A-D) free amino acid concentrations and (E) energy metabolism hormone concentrations.
Figure 1.pdfScatter points are individual milk samples after natural log transformation, with fitted regression line and surrounding confidence interval for the association of the individual bioactive substance concentration with postpartum day of sample collection. *Slope was significantly different than 0 for adiponectin, arginine, asparagine, citrulline, glutamate, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, taurine, threonine, tyrosine, and valine.

Table1: Characteristics of the study cohort
Table 1.pdfDiabetes in pregnancy: type 1, type 2, or gestational diabetes
Obesity in pregnancy: pre-pregnancy body mass index > 30 kg/m2

Table 2: Median between group differences* in energy metabolism hormones and free amino acid concentrations in early human milk samples (N=49)
Table 2.pdf*Quantile regression with a separate model for each bioactive substance. Models were adjusted for day of sample collection. Bold, red indicate p-value < 0.05.
(DM) Diabetes in pregnancy: type 1, type 2, or gestational diabetes
(OB) Obesity in pregnancy: pre-pregnancy body mass index > 30 kg/m2