Circulatory insulin-like growth factor-I and brain volumes in relation to neurodevelopmental outcome in very preterm infants.
BACKGROUND
To evaluate the relationships between postnatal change in circulatory insulin-like growth factor-I (IGF-I) concentrations, brain volumes, and developmental outcome at 2 y of age in very preterm infants.


METHODS
IGF-I was measured weekly, and nutritional intake was calculated daily from birth until a postmenstrual age (PMA) of 35 wk. Individual β coefficients for IGF-I, IGF-I(B), representing the rate of increase in IGF-I from birth until a PMA of 35 wk were calculated. Brain magnetic resonance imaging was performed at term age, with segmentation into total brain, cerebellar, gray matter, and unmyelinated white matter volume (UWMV). Developmental outcome was evaluated using Bayley Scales of Infant Development-II.


RESULTS
Forty-nine infants, with mean gestational age (GA) of 26.0 wk, were evaluated at mean 24.6 mo corrected age. Higher IGF-I(B), UWMV, and cerebellar volume were associated with a decreased risk for a Mental Developmental Index (MDI) < 85 (odds ratio (95% confidence interval): 0.6 (0.4-0.9), 0.96 (0.94-0.99), and 0.78 (0.6-0.96), respectively). In multivariate analysis, higher IGF-I(B) and higher UWMV combined with female gender constituted the two models with the highest predictive value for MDI > 85.


CONCLUSIONS
A higher rate of increase in circulating IGF-I is associated with a decreased risk for subnormal MDI at 2 y of corrected age. This relationship is in part dependent on brain volume at term age.
Department of Pediatrics, Institute of Clinical Sciences, Lund, Skane University Hospital, Lund University, Lund, Sweden.
Ingrid
I
Hansen-Pupp
Holger
H
Hövel
Chatarina
C
Löfqvist
Lena
L
Hellström-Westas
Vineta
V
Fellman
Petra S
PS
Hüppi
Ann
A
Hellström
David
D
Ley
D001921:Brain / Q000254:growth & development*; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena; D062071:Infant, Extremely Premature / Q000254:growth & development*; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D013548:Sweden
D007334:Insulin-Like Growth Factor I