Breast-feeding and growth factors in preterm newborn infants.
BACKGROUND
We analyzed the role that nutrition and the insulin-like growth factors IGF-I and IGFBP-3 play on neonatal growth.


METHODS
Full-term and preterm infants with 1 and 3 weeks of postnatal life (n = 54 and n = 33, respectively) were studied. Anthropmetric variables, daily intake of energy and nutrients, and serum levels of IGF-I and IGFBP-3 were measured.


RESULTS
At the first week after birth, preterm infants had lower IGF-I levels than did those in the control group. At the third week of postnatal life, serum IGF-I and IGFBP-3 levels showed a significant increase. Preterm infants born before 33 gestational weeks showed lower IGF-I (p < 0.02) and IGFBP-3 (p < 0.02) levels than those born between 33 and 37 gestational weeks. Preterm infants fed with human milk supplemented with a formula showed higher serum IGF-I levels than those fed exclusively with a milk formula (mean +/- SEM 48.2 +/- 9.5 micrograms/L vs. 25.4 +/- 4.4 micrograms/L, p < 0.05). IGF-I and IGFBP-3 were correlated between themselves and with energy and protein intake. Multiple regression analysis confirmed that energy intake and serum IGFBP-3 levels were the most predictable variables with regard to IGF-I levels at neonatal period.


CONCLUSIONS
These feedings suggest that IGF-I levels during the neonatal periods are influenced by the maturity stage of the newborn, energy intake, and the type of lactation.
Díaz-Gómez
N M
NM
University of La Laguna, Hospital Universitario de Canarias, Department of Pediatrics, Tenerife, Canary Islands, Spain.
Domenech
E
E
Barroso
F
F
D000886:Anthropometry; D001942:Breast Feeding; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005865:Gestational Age; D006133:Growth Substances / Q000097:blood*; D006801:Humans; D007225:Infant Food; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007234:Infant, Premature; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D012044:Regression Analysis
D004044:Dietary Proteins; D006133:Growth Substances; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I