title: Association of cord blood leptin, soluble leptin receptor, insulin-like growth factor-I and insulin-like growth factor-binding protein-1 on birth indices in healthy full-term newborns.
abstract: BACKGROUND
  Leptin and insulin-like growth factor-I (IGF-I) promote fetal growth. Their availability is modulated by soluble leptin receptor (SLR) and insulin-like growth factor-binding proteins (IGFBP). Studies that accounted for SLR levels when investigating the association of leptin, IGF-I and IGFBPs on birth indices are scarce.
  
  
  METHODS
  Cord blood leptin, SLR, IGF-I, IGFBP-1 and their association with birth indices were studied in term newborns (n = 110; males = 60). Data were compared between males and females using the Mann-Whitney U test/unpaired Student's t test as appropriate. Univariate correlations and multiple regression analyses were performed to identify variables significantly influencing birth indices.
  
  
  RESULTS
  Birth indices were comparable between male and female newborns. Females had a significantly lower SLR (p = 0.0142), a higher leptin/Ponderal index (p = 0.033) and a higher free leptin index (leptin/SLR) (p = 0.0081). Leptin and male gender positively and IGFBP-1 negatively influenced birth weight (p = 0.0005, p = 0.02, and p = 0.005, respectively) and head circumference (p = 0.0052, p = 0.0098, and p = 0.0183, respectively) when accounted for other variables. When tested in a different multiple regression model, the free leptin index positively influenced crown-heel length (p = 0.0016) in addition to birth weight (p < 0.0001) and head circumference (p = 0.0016).
  
  
  CONCLUSIONS
  In healthy full-term pregnancies, cord blood leptin and IGFBP-1 exert independent and opposing effects on fetal growth.
authors.affiliation: Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka.
authors.forename: Kamani H
authors.initials: KH
authors.lastname: Tennekoon
authors.forename: Jayanthiny
authors.initials: J
authors.lastname: Poopalapillai
authors.forename: Akila G
authors.initials: AG
authors.lastname: Karunanayake
authors.forename: Hasini D
authors.initials: HD
authors.lastname: Jayasinghe
authors.forename: Jayalath M
authors.initials: JM
authors.lastname: Kumarasiri
authors.forename: Ajita P
authors.initials: AP
authors.lastname: De S Wijesundera
authors.forename: Eric H
authors.initials: EH
authors.lastname: Karunanayake
mesh_terms: D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D020738:Leptin / Q000097:blood*; D008297:Male; D054411:Receptors, Leptin / Q000097:blood*; D047929:Term Birth / Q000502:physiology*
chemical_list: D018970:Insulin-Like Growth Factor Binding Protein 1; D020738:Leptin; D054411:Receptors, Leptin; D007334:Insulin-Like Growth Factor I