title: Effect of maternal body mass index on hormones in breast milk: a systematic review.
abstract: BACKGROUND
  Maternal Body Mass Index (BMI) is positively associated with infant obesity risk. Breast milk contains a number of hormones that may influence infant metabolism during the neonatal period; these may have additional downstream effects on infant appetite regulatory pathways, thereby influencing propensity towards obesity in later life.
  
  
  OBJECTIVE
  To conduct a systematic review of studies examining the association between maternal BMI and the concentration of appetite-regulating hormones in breast milk.
  
  
  METHODS
  Pubmed was searched for studies reporting the association between maternal BMI and leptin, adiponectin, insulin, ghrelin, resistin, obestatin, Peptide YY and Glucagon-Like Peptide 1 in breast milk.
  
  
  RESULTS
  Twenty six studies were identified and included in the systematic review. There was a high degree of variability between studies with regard to collection, preparation and analysis of breast milk samples. Eleven of fifteen studies reporting breast milk leptin found a positive association between maternal BMI and milk leptin concentration. Two of nine studies investigating adiponectin found an association between maternal BMI and breast milk adiponectin concentration; however significance was lost in one study following adjustment for time post-partum. No association was seen between maternal BMI and milk adiponectin in the other seven studies identified. Evidence for an association between other appetite regulating hormones and maternal BMI was either inconclusive, or lacking.
  
  
  CONCLUSIONS
  A positive association between maternal BMI and breast milk leptin concentration is consistently found in most studies, despite variable methodology. Evidence for such an association with breast milk adiponectin concentration, however, is lacking with additional research needed for other hormones including insulin, ghrelin, resistin, obestatin, peptide YY and glucagon-like peptide-1. As most current studies have been conducted with small sample sizes, future studies should ensure adequate sample sizes and standardized methodology.
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Andreas
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hyde
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: Chris
authors.initials: C
authors.lastname: Gale
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: James R C
authors.initials: JR
authors.lastname: Parkinson
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: Suzan
authors.initials: S
authors.lastname: Jeffries
authors.affiliation: Section of Computational and Systems Medicine, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London, United Kingdom.
authors.forename: Elaine
authors.initials: E
authors.lastname: Holmes
authors.affiliation: Section of Neonatal Medicine, Department of Medicine, Chelsea & Westminster Hospital, Imperial College London, London, United Kingdom.
authors.forename: Neena
authors.initials: N
authors.lastname: Modi
mesh_terms: D015992:Body Mass Index; D005260:Female; D006728:Hormones / Q000032:analysis*; D006801:Humans; D008895:Milk, Human / Q000737:chemistry*; D009035:Mothers
chemical_list: D006728:Hormones