title: IGF-I at 9 and 36 months of age — relations with body composition and  diet at 3 years — the SKOT cohort.
abstract: OBJECTIVE
  High infancy levels of insulin-like growth factor-I (IGF-I) have been associated with increased linear growth and fat-free mass (FFM) but also with risk of obesity. This paper examines how IGF-I at 9 and 36 months relates to diet and body composition.
  
  
  METHODS
  Healthy term infants from the prospective cohort study, SKOT, were examined at 9 and 36 months with anthropometry, bioelectrical impedance (36 months), 7-day food records and blood analysis of IGF-I and IGFBP-3 by chemiluminescent immunometric assay.
  
  
  RESULTS
  IGF-I at 36 months (n = 229) was positively correlated with 9 months values and values were considerably higher in girls (43%). Children breastfed at 9 months had lower IGF-I concentrations at 9 months but reached the same IGF-I concentrations at 36 months as infants not breastfed at 9 months. IGF-I at 36 months was positively associated with height, weight, BMI, predicted FFM and FFM index (FFM/height (kg/m2)). Although there also was a positive association with predicted fat mass (FM) there was no association with FM index (FM/height (kg/m2)). Further, a negative association with skin fold thickness was observed. A change in IGF-I from 9–36 months was positively related to FFM and FFM index but not BMI, FM and FM index. No associations were seen between IGF-I and current intake of milk, meat or protein energy percentage, but both fat and saturated fat energy percentage were negatively associated with IGF-I.
  
  
  CONCLUSIONS
  IGF-I concentrations were positively associated with growth but not with adiposity at this age. However, the higher tempo of growth may influence age at adiposity rebound and thereby later risk of obesity. Milk and protein intake at 36 months did not influence IGF-I but there was a negative association with intake of fat and saturated fat. The implications of this finding for development of obesity need further exploration.
authors.forename: K T
authors.initials: KT
authors.lastname: Ejlerskov
authors.forename: A
authors.initials: A
authors.lastname: Larnkjaer
authors.forename: D
authors.initials: D
authors.lastname: Pedersen
authors.forename: C
authors.initials: C
authors.lastname: Ritz
authors.forename: C
authors.initials: C
authors.lastname: Mølgaard
authors.forename: K F
authors.initials: KF
authors.lastname: Michaelsen
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D002675:Child, Preschool; D004032:Diet; D002149:Energy Intake; D005260:Female; D006801:Humans; D007223:Infant; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009765:Obesity; D011446:Prospective Studies
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I