title: IGF-I and IGFBP-3 in healthy 9 month old infants from the SKOT cohort: breastfeeding, diet, and later obesity.
abstract: BACKGROUND
  High IGF-I concentrations in infancy have been associated with later obesity but the interactions between diet, IGF-I concentrations and growth in early life are complex and involve programming of the IGF-I axis.
  
  
  OBJECTIVE
  This paper examines how IGF-I and IGFBP-3 concentrations measured at age 9 months are related to diet and growth in infancy.
  
  
  METHODS
  In the Danish SKOT cohort healthy term infants were included at age 9 months with follow-up at age 18 months. Total 252 infants had a full data set and were included in the analysis. Measurements include weight, length, skinfold thickness, waist circumference, 7-d food records, and blood analysis of IGF-I, and IGFBP-3.
  
  
  RESULTS
  Infants not being breastfed at 9 months of age (46%) had higher median IGF-I concentration than breastfed infants (51.6 vs. 44.2 ng/mL, P=0.0005) and there was a negative dose response effect of daily numbers of breastfeedings on IGF-I concentration. IGF-I concentration was negatively associated with birth weight and positively related to increase in weight, length and BMI between birth and 9 months. Between 9 months and 18 months of age increase in length was positively and increase in BMI was negatively related to IGF-I concentration.
  
  
  CONCLUSIONS
  Breastfeeding has a strong negative effect on IGF-I concentrations in late infancy. Although IGF-I concentrations at 9 months of age were negatively associated with change in BMI during the following 9 months we speculate that this could reflect an early adiposity rebound and thereby an increased risk of obesity later in life.
authors.affiliation: Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, 1958 Frederiksberg, Denmark. alm@life.ku.dk
authors.forename: Anja L
authors.initials: AL
authors.lastname: Madsen
authors.forename: Anni
authors.initials: A
authors.lastname: Larnkjær
authors.forename: Christian
authors.initials: C
authors.lastname: Mølgaard
authors.forename: Kim F
authors.initials: KF
authors.lastname: Michaelsen
mesh_terms: D001823:Body Composition; D001942:Breast Feeding; D015331:Cohort Studies; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007229:Infant Welfare; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009765:Obesity
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I