Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2017 Mar;56(2):613-620.
doi: 10.1007/s00394-015-1105-9. Epub 2015 Nov 30.

Role of selected amino acids on plasma IGF-I concentration in infants

Manja Fleddermann  1 , Hans Demmelmair  2 , Veit Grote  2 , Martin Bidlingmaier  3 , Philipp Grimminger  3 , Maximilian Bielohuby  3 , Berthold Koletzko  2
Affiliations
Randomized Controlled Trial

Role of selected amino acids on plasma IGF-I concentration in infants

Manja Fleddermann et al. Eur J Nutr. 2017 Mar.

Abstract

Purpose: Insulin-like growth factor-I (IGF-I) is related to growth and its secretion is modified by protein intake in early infancy. We examined the relationship of dietary protein and circulating amino acids on plasma IGF-I levels and early growth.

Methods: Healthy formula-fed infants (n = 213) were randomly assigned to receive either a protein-reduced infant formula with alpha-lactalbumin-enriched whey and free tryptophan and phenylalanine (IF) or an isocaloric standard formula without free amino acids (CF) for the first 120 days of life. A group of breastfed (BF) infants was studied as a non-randomized reference cohort. Biochemical variables were measured shortly after birth (subpopulation) and at an age of 120 days. A path analysis was used to explore the relationship between IGF-I, insulin and amino acids. Results are derived from secondary analyses of a randomized controlled trial.

Results: Plasma concentrations of IGF-I at 120 days were significantly higher in IF than in CF infants [58.5 (15.0) vs. 53.7 (9.95) ng/mL; p = 0.020]. BF infants showed lower IGF-I concentrations of 41.6 (10.7) ng/mL. All amino acids but Thr and Cit had a more marked effect on insulin than on IGF-I level. Considering weight, sex and feeding group, Trp explained an equal percentage of variance of IGF-I and insulin (total R 2 12.5 % of IGF-I and 12.3 % of insulin), while branched-chain AA explained an up to twofold higher variance of insulin than IGF-I. Compared to CF, IF explained 18.9 % of the IGF-I level (p = 0.03), while for insulin no direct effect was detectable.

Conclusion: Higher IGF-I concentrations and growth velocities in infants receiving protein-reduced IF indicate that the protein concentration of an infant formula alone does not control IGF-I levels and growth. Other components (e.g., selected amino acids) of infant formulae might control directly or indirectly via insulin influence IGF-I.

Keywords: Alpha-lactalbumin; Growth regulation; Human milk; Infant formula; Insulin-like growth factor-I.

PubMed Disclaimer

References

    1. Growth Horm IGF Res. 2013 Oct;23(5):149-58 - PubMed
    1. PLoS One. 2014 Jan 13;9(1):e85054 - PubMed
    1. Am J Clin Nutr. 2000 Jul;72(1):96-105 - PubMed
    1. J Am Diet Assoc. 2002 Nov;102(11):1621-30 - PubMed
    1. Endocr Rev. 1994 Feb;15(1):80-101 - PubMed

Publication types

LinkOut - more resources