title: Cord IGF-I concentrations in Indian newborns: associations with neonatal body composition and maternal determinants.
abstract: BACKGROUND
  Indian newborns have been described as 'thin-fat' compared with European babies, but little is known about how this phenotype relates to the foetal growth factor IGF-I (insulin-like growth factor I) or its binding protein IGFBP-3.
  
  
  OBJECTIVE
  To assess cord IGF-I and IGFBP-3 concentrations in a sample of Indian newborns and evaluate their associations with neonatal adiposity and maternal factors.
  
  
  METHODS
  A prospective cohort study of 146 pregnant mothers with dietary, anthropometric and biochemical measurements at 28 and 34 weeks gestation. Neonatal weight, length, skin-folds, circumferences, and cord blood IGF-I and IGFBP-3 concentrations were measured at birth.
  
  
  RESULTS
  Average cord IGF-I and IGFBP-3 concentrations were 46.6 (2.2) and 1269.4 (41) ng mL(-1) , respectively. Girls had higher mean IGF-I than boys (51.4 ng mL(-1) vs. 42.9 ng mL(-1) ; P < 0.03), but IGFBP-3 did not differ. Cord IGF-I was positively correlated with all birth size measures except length, and most strongly with neonatal sum-of-skin-folds (r = 0.50, P < 0.001). IGFBP-3 was positively correlated with ponderal index, sum-of-skin-folds and placenta weight (r = 0.21, 0.19, 0.16, respectively; P < 0.05). Of maternal demographic and anthropometric characteristics, only parity was correlated with cord IGF-I (r = 0.27, P < 0.001). Among dietary behaviours, maternal daily milk intake at 34 weeks gestation predicted higher cord IGF-I compared to no-milk intake (51.8 ng mL(-1) vs. 36.5 ng mL(-1) , P < 0.01) after controlling for maternal characteristics, placental weight, and newborn gestational age, sex, weight and sum-of-skin-folds. Sum-of-skin-folds were positively associated with cord IGF-I in this multivariate model (57.3 ng mL(-1) vs. 35.1 ng mL(-1) for highest and lowest sum-of skin-fold quartile, P < 0.001). IGFBP-3 did not show significant relationships with these covariates.
  
  
  CONCLUSIONS
  In this Indian study, cord IGF-I concentration was associated with greater adiposity among newborns. Maternal milk intake may play a role in this relationship.
authors.affiliation: Anthropology Department and Human Biology Program, Indiana University, Bloomington, IN, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Wiley
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: H G
authors.initials: HG
authors.lastname: Lubree
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: S M
authors.initials: SM
authors.lastname: Joshi
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: D S
authors.initials: DS
authors.lastname: Bhat
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: L V
authors.initials: LV
authors.lastname: Ramdas
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: A S
authors.initials: AS
authors.lastname: Rao
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: N V
authors.initials: NV
authors.lastname: Thuse
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: V U
authors.initials: VU
authors.lastname: Deshpande
authors.affiliation: Kamalanayan Bajaj Diabetology Research Centre, KEM Hospital Research Centre, KEM Hospital, Pune, Maharashtra, India.
authors.forename: C S
authors.initials: CS
authors.lastname: Yajnik
mesh_terms: D000818:Animals; D001724:Birth Weight; D001823:Body Composition; D015992:Body Mass Index; D001942:Breast Feeding; D005247:Feeding Behavior; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D047109:Fetal Development; D005865:Gestational Age; D006801:Humans; D007194:India; D007223:Infant; D007231:Infant, Newborn / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008892:Milk; D009035:Mothers; D010298:Parity; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I
keywords: Cord IGF-I; maternal milk intake; neonatal anthropometry; ‘thin fat’ Indian baby