AUTHOR=Galante Laura , Pundir Shikha , Lagström Hanna , Rautava Samuli , Reynolds Clare Marie , Milan Amber Marie , Cameron-Smith David , Vickers Mark Hedley 

TITLE=Growth Factor Concentrations in Human Milk Are Associated With Infant Weight and BMI From Birth to 5 Years

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 7 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2020.00110

DOI=10.3389/fnut.2020.00110

ISSN=2296-861X

ABSTRACT=Background: Human milk bioactives may play a role in infant health and development. Although the variability in their concentrations in milk is well established, the impact of differential milk profiles on infant growth outcomes remains unclear. We hypothesized that different concentrations of metabolic hormones would be correlated with different weight and BMI in the infants beyond the first year of life.
Methods: Milk samples at 2.6 (±0.4) months after birth and anthropometric measures at 13 months, 2, 3 and 5 years were collected as part of the Finnish STEPS cohort study from 501 mothers and the respective 507 infants. Leptin, adiponectin, insulin-like growth factor (IGF)-1 and cyclic glycine-proline (cGP) in milk were analysed. Generalized liner models and a repeated measures mixed model were used to examine correlations between milk hormone concentrations and weight and BMI z-scores across time, at each time-point, and weight gain from birth to each follow-up visit. All models were corrected for birthweight, infant sex, duration of exclusive and total breastfeeding, time of introduction of solid foods and maternal pre-pregnancy BMI.
Results: Milk IGF-1 concentrations were directly proportional to weight at 13 months (p=0.004) but negatively correlated to weight at 3 (p=0.011) and 5 years of age (p=0.049). cGP was negatively correlated with overall weight gain across the 5 years (p=0.019) but proportional to BMI at 5 years (p=0.021). Leptin and adiponectin did not display correlations with infant growth at this time. Sex interactions were also absent.
Conclusions: Our results suggest that the interplay between human milk-borne IGF-1 and cGP is similar to that reported in other mammals and may have an important role in defining infant growth trajectories beyond the first year of life. Further research should explore the determinants and origins of these milk-borne compounds and evaluate their effect on infant growth and metabolism.