Influence of insulin-like growth factor I and nutrition during phases of postnatal growth in very preterm infants.
Pronounced growth restriction (GR) occurs after very preterm birth. The interaction between IGF-I, nutritional intake, and growth was evaluated prospectively in 64 infants with a mean (SD) GA of 25.7 (1.9) wk. Blood sampling of IGF-I and measurements of weight, length, and head circumference were performed weekly until discharge. Daily calculation of nutritional intake was performed. Standard deviation scores (SDSs) for growth parameters defined two growth phases: GR phase (birth until lowest SDS) and catch-up (CU) phase (lowest SDS until 35 gestational weeks). IGF-I concentrations during the first postnatal weeks were low and increased at 30 wk GA, irrespective of GA at birth, coinciding with initiation of CU growth. Concentrations of IGF-I were positively associated with change in weight SDS during the GR phase, p = 0.001 and CU phase, p = 0.004-0.027. Protein and energy intake were not associated with change in SDS weight during the GR phase as opposed to the CU phase (p < 0.001, respectively). Nutritional intake did not correlate to concentrations of IGF-I before 30 wk GA. IGF-I is associated with growth at an earlier postnatal age than nutrient intake and the effect of nutrition on levels of IGF-I may be restricted to the period of established CU growth.
Department of Pediatrics, Lund University, 221 85 Lund, Sweden. ingrid.pupp@skane.se
Ingrid
I
Hansen-Pupp
Chatarina
C
Löfqvist
Staffan
S
Polberger
Aimon
A
Niklasson
Vineta
V
Fellman
Ann
A
Hellström
David
D
Ley
D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D001623:Betamethasone / Q000008:administration & dosage; D015415:Biomarkers / Q000097:blood; D001827:Body Height; D049628:Body Size; D001835:Body Weight; D001942:Breast Feeding; D002508:Cephalometry; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005865:Gestational Age; D006257:Head / Q000254:growth & development; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood / Q000254:growth & development*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008894:Milk Proteins / Q000008:administration & dosage; D009752:Nutritional Status; D018529:Nutritional Support; D011446:Prospective Studies; D013548:Sweden
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D004044:Dietary Proteins; D008894:Milk Proteins; D007334:Insulin-Like Growth Factor I; D001623:Betamethasone; D006854:Hydrocortisone