Maternal Body Mass Index Influence on Breast Milk Fatty Acid Esters of Hydroxy Fatty Acids and Their Potential Role in Developmental Programming (OR30-07-19).

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a novel class of endogenous lipids with suspected anti-inflammatory and anti-diabetic properties in adults. They have been reported to be present in breast milk (BM), but there is no data about their role in infant growth and nutrition. Our objective was to determine the role of maternal body mass index (BMI) on BM FAHFA composition and to delineate the association of these BM fatty acids on infant growth and adiposity. This is a secondary analysis of a randomized controlled trial of maternal vitamin D supplementation during lactation (NCT00412074). We included 40 control mother-infant dyads who had BM samples at one (V1) and four (V4) months and outcome data available. At V1 and V4, maternal and infant anthropometrics were measured, dual energy absorptiometry (DXA) scans conducted, and BM samples collected. BM lipids were measured using established methods of UHPLC-C30RP/HRAM mass spectrometry. Our primary infant growth outcomes were percentage of fat and lean mass, fat mass index, and fat-free mass index. Redundancy analysis (RDA) was used to analyze the relation between individual lipids, maternal BMI, and infant growth. Focusing on V1 measurements, we computed the unadjusted associations between maternal BMI with BM lipids; BM lipids with infant growth using Pearson’s correlations; and the adjusted associations of BM lipids at V1 with infant growth using linear regression with adjustment for relevant covariates. The mean maternal BMI was 29 kg/m2. There was no correlation between maternal BMI and reported dietary intake of fat. Higher maternal BMI was associated with a higher concentration of saturated and monounsaturated FAHFAs, and a lower concentration of polyunsaturated FAHFAs in BM at V1. In an unadjusted model, saturated and monounsaturated FAHFAs were associated with higher infant fat mass and lower lean mass. The converse was seen with polyunsaturated FAHFAs which were associated with lower infant fat mass and higher lean mass. In a fully adjusted model, these associations were attenuated but the overall pattern persisted (Table 1). Maternal BMI influences the FAHFA composition of BM. In turn, BM FAHFA composition may play a role in programming infant growth patterns. The Nutritional Obesity Research Consortium Grant.