title: Ecological pressures and milk metabolic hormones of ethnic Tibetans living at different altitudes.
abstract: BACKGROUND
  Very little is known about how milk hormones, shown to influence growth during infancy, may contribute to patterns of altered growth in high altitude living infants.
  
  
  OBJECTIVE
  This study investigated the association between maternal BMI, the metabolic hormones adiponectin and leptin in human milk and infant weight for age z-scores (WAZ) in Tibetans.
  
  
  METHODS
  A sample of 116 mothers and infants (aged 0-36 months) were recruited from two locations: the Nubri Valley, Nepal (rural; altitude = 2400-3900 m) and Kathmandu, Nepal (urban, 1400 m). Milk samples, anthropometrics, biological data and environmental information were collected on mothers and infants. Milk was analysed for leptin and adiponectin.
  
  
  RESULTS
  Maternal BMI was significantly associated with milk leptin content, but not adiponectin in either group. In the rural high altitude sample, child WAZ declined with age, but no such decline was seen in the urban sample.
  
  
  CONCLUSIONS
  Milk leptin and adiponectin were not associated with infant growth in the rural Nubri sample, but were both inversely associated with infant WAZ in the Kathmandu sample. It appears that, in ecologically stressful environments, associations between milk hormones and growth during infancy may not be detectable in cross-sectional studies.
authors.affiliation: a Department of Anthropology , Washington University in St. Louis , St. Louis , MO , USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Quinn
authors.affiliation: a Department of Anthropology , Washington University in St. Louis , St. Louis , MO , USA.
authors.forename: Geoff
authors.initials: G
authors.lastname: Childs
mesh_terms: D052242:Adiponectin / Q000378:metabolism*; D000531:Altitude; D015992:Body Mass Index; D002657:Child Development; D002675:Child, Preschool; D055669:Ecological and Environmental Phenomena; D005006:Ethnicity; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D020738:Leptin / Q000378:metabolism*; D008895:Milk, Human / Q000378:metabolism*; D009035:Mothers; D012044:Regression Analysis; D018609:Tibet; D014944:World Health Organization
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D020738:Leptin
keywords: Adiponectin; breast milk; high altitude; human milk; human variation; infant WAZ; infant feeding; leptin