Cord blood leptin and insulin-like growth factor levels are independent predictors of fetal growth.
The insulin-like growth factor (IGF) system is the dominant endocrine regulator of fetal growth, whereas insulin has a permissive role. Although a role for leptin in fetal growth has been suggested recently, the mechanism by which leptin may be related to fetal growth is not known; but leptin may interact with the IGF system in utero as it does in the extrauterine life. In the context of a hospital-based case control study, we collected anthropometric and demographic data and measured serum leptin, IGF-I, IGF-II, insulin, cortisol, and IGF binding protein 3 concentrations in 142 cord blood samples from full-term deliveries. Cord leptin, IGF-I, and insulin levels correlated positively with birth weight (r = 0.46, r = 0.41, and r = 0.21, respectively, P < 0.01) by univariate analysis and were significantly higher in large-for-gestational-age (LGA) infants, compared with appropriate-for-gestational-age (AGA) infants. Cord leptin concentrations correlated with insulin levels (r = 0.36, P < 0.01) but not with IGF-I levels (r = 0.20). Multiple linear and logistic regression analysis demonstrated an independent positive relationship of both leptin and IGF-I with birth weight and AGA/LGA status. The positive association of leptin levels with birth weight and AGA/LGA status cannot be attributed to IGF-I. This suggests the existence of alternative mechanisms underlying leptin's associations with fetal growth that should be further explored.
Christou
H
H
Division of Newborn Medicine, Children's Hospital, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Connors
J M
JM
Ziotopoulou
M
M
Hatzidakis
V
V
Papathanassoglou
E
E
Ringer
S A
SA
Mantzoros
C S
CS
D000704:Analysis of Variance; D001724:Birth Weight; D015992:Body Mass Index; D016022:Case-Control Studies; D005314:Embryonic and Fetal Development; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007231:Infant, Newborn / Q000097:blood*; D007328:Insulin / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007335:Insulin-Like Growth Factor II / Q000032:analysis*; D020738:Leptin / Q000097:blood*; D008297:Male; D015203:Reproducibility of Results
D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D020738:Leptin; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D006854:Hydrocortisone