title: Evaluation of leptin in breast milk, lactating mothers and their infants.
abstract: OBJECTIVE
  Leptin is present in human milk, but it is not clear what the relationship between breast milk (BM) leptin levels and maternal and infant serum leptin concentrations is. The objective of this study was to evaluate the leptin concentration in BM and to investigate its relationship with infants' and mothers' anthropometric parameters and with serum leptin concentration in breast-fed (BF) infants and lactating mothers.
  
  
  METHODS
  We enrolled 36 adequate for gestational age healthy, exclusively BF, term infants aged <6 months. Leptin concentration in serum and BM was determined by radioimmunoassay (RIA) test (human-leptin-RIA-sensitive, Mediagnost). Infants' and mothers' weights, lengths and body mass indexes (BMI) were measured.
  
  
  RESULTS
  The median leptin concentration was 3.42 ng/ml (interquartile range (IR): 2.65) in BF infants' serum, 3.02 ng/ml (IR: 2.85) in mothers' serum (n=17) and 0.51 ng/ml (IR: 0.34) in BM (n=24). BM leptin concentrations were significantly lower than serum BF infant (P<0.001) and maternal (P<0.001) leptin levels. Infant serum leptin concentration correlated positively with infant weight (r=0.437, P=0.008) and BMI (r=0.561, P=0.004). Mother serum leptin levels correlated positively with weight (r=0.755, P<0.001) and BMI (r=0.661, P=0.007). No correlations were found between BM leptin and serum leptin concentrations in BF infants and mothers.
  
  
  CONCLUSIONS
  We confirmed the presence of leptin in BM at a lower concentration than that found in infant and lactating mother serum. We observed a positive correlation between serum leptin levels in BF infants and their growth parameters.
authors.affiliation: Department of Paediatrics, University of Turin, Regina Margherita Children's Hospital, Torino, 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: E
authors.initials: E
authors.lastname: Petrucci
authors.forename: M M
authors.initials: MM
authors.lastname: Lupica
authors.forename: M F
authors.initials: MF
authors.lastname: Fissore
authors.forename: R
authors.initials: R
authors.lastname: Oggero
authors.forename: L
authors.initials: L
authors.lastname: Silvestro
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D001942:Breast Feeding; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn / Q000097:blood* / Q000254:growth & development; D007774:Lactation / Q000378:metabolism; D020738:Leptin / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D008297:Male; D008895:Milk, Human / Q000737:chemistry* / Q000378:metabolism; D009035:Mothers
chemical_list: D020738:Leptin