title: High serum leptin levels in infancy can potentially predict obesity in childhood, especially in formula-fed infants.
abstract: OBJECTIVE
  To investigate serum leptin levels in breast-fed and formula-fed infants in infancy and their possible relationship to body mass index (BMI) in childhood.
  
  
  METHODS
  We enrolled 237 healthy term infants between September 2000 and April 2004 and tested their serum leptin levels, took anthropometric measurements and calculated BMI. A follow-up study was carried out to evaluate the BMI of 89 of these infants in childhood, in relation to their serum leptin levels in infancy, at a median (interquartile range) age of 8.8 years (7.8-10.2). The statistical significance of this multivariate analysis was set at p < 0.05.
  
  
  RESULTS
  Breast-fed infants had significantly higher serum leptin levels than formula-fed ones (p < 0.05). Children who were formula-fed in infancy had a significantly higher BMI, at follow-up, than those who were breast-fed (p < 0.001). Furthermore, we identified a leptin cut-off value of 2.7 ng/mL, below which infants had a higher BMI in childhood.
  
  
  CONCLUSIONS
  A higher leptin level in infancy may be inversely associated with BMI in childhood, suggesting that this hormone in infancy is a potential predictor of obesity in later life. Further investigation is required to be conclusive and to confirm our empirical evidence.
authors.affiliation: Department of Paediatrics, University of Turin, Regina Margherita Children's Hospital, Azienda Ospedaliera Città della Salute e della Scienza di Torino, Turin, Italy. francesco.savino@unito.it
authors.forename: F
authors.initials: F
authors.lastname: Savino
authors.forename: S A
authors.initials: SA
authors.lastname: Liguori
authors.forename: S
authors.initials: S
authors.lastname: Benetti
authors.forename: M
authors.initials: M
authors.lastname: Sorrenti
authors.forename: M F
authors.initials: MF
authors.lastname: Fissore
authors.forename: L
authors.initials: L
authors.lastname: Cordero di Montezemolo
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001942:Breast Feeding; D002648:Child; D003661:Decision Support Techniques; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D041943:Infant Formula; D020738:Leptin / Q000097:blood*; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D063766:Pediatric Obesity / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D020738:Leptin
keywords: Body mass index; Breastfeeding; Childhood; Infancy; Leptin