ESPE Abstracts

Introduction: Insulin-like growth factor (IGF)-1, IGF binding proteins (IGFBPs) and regulatory metabolites, including cyclic Glycine-Proline (cGP), have a possible role in modifying infant growth trajectories through their effects on linear growth, and body composition. There is no consensus on how maternal BMI affects breast milk IGF1 level.

Aim: We reviewed the recent literature about human milk (IGF)-1, and cGP concentrations in relation to infantile growth and body composition.

Results: In 507 infants, higher milk IGF-1 was associated with higher weight at 13 months (P= 0.004) but lower weight at 3 and 5 years of age. Higher milk cGP concentration was associated with lower weight across the 5 years but with higher BMI at 5 years. In 675 unselected infants at ages 3 and 12 months, those who were formula milk-fed had higher IGF-I concentrations at 3 months, and they showed greater gains in weight, length, BMI, and adiposity between age 3 and 12 mo. In a large cohort Korean study, (547,669 infants), breastfed (BF) children were shorter and lighter by 3.5 years and 4.5 years versus formula fed children. Exclusive BF children for 6 months (compared to < 1 month) eliminated the positive relation of high birth weight and rapid weight gain on the fat mass index at 3 years. In 103 mother -infant pairs, the breast milk consumed by the infants with high weight gain contained higher levels of IGF-1 than that consumed by those with low weight gain during 3 months of lactation. In 40 lactating women, pre-pregnancy BMI was associated with breast milk IGF-1 levels and post-feed breast milk IGF-1 levels of mothers with obesity were correlated with infant's weight for length z-score at 2 months. In 45 mothers with Gestational diabetes mellitus (GDM) and their babies a positive correlation was detected between the breast milk IGF-1 levels and the weight, head and abdominal circumferences of their babies. Breast milk samples (n= 569) donated by mothers from five European countries showed that milk IGFI concentrations correlated with both protein and fat contents, suggesting a possible regulatory role of IGF in milk macronutrient synthesis. Milk-borne IGF-1 acts as a growth factor for gut maturation.

Conclusions: Human milk IGF-1 and cGP may have an important role in shaping infant growth trajectories during and after the first year of life. Breast milk of obese mothers has higher IGF1 than normal weight mothers.