title: Genetic and environmental influences on human cord blood leptin concentration.
abstract: OBJECTIVE
  To examine in a population sample of cord blood the time structure (chronome) of leptin, an adipocyte-derived hormone, and to assess any effect of a familial history of noninsulin-dependent diabetes mellitus and obesity, separately, on both the maternal and the paternal side.
  
  
  METHODS
  Leptin concentration was determined in cord blood from 93 infants. Effects of gender, gestational age, birth weight, maternal weight, familial antecedents of obesity and noninsulin-dependent diabetes mellitus, and circadian and about-yearly stage were assessed by linear regression and ANOVA.
  
  
  RESULTS
  Cord blood leptin concentration is elevated in the presence of a family history of obesity on the paternal side, but not on the maternal side. Leptin concentrations are higher in spring and summer than in fall and are higher in infants born before noon. In keeping with earlier work, leptin concentration in cord blood correlates positively with birth weight and height and is higher in infants who are appropriate for or large for gestational age than in infants who are small for gestational age or born prematurely.
  
  
  CONCLUSIONS
  Changes along the scales of the day and the seasons point to synchronizing environmental as well as genetic influence. An association of cord blood leptin concentration with obesity on the paternal side may help clarify the role of leptin in parental contributions to human obesity and may prompt focus on cholesterol metabolism.
authors.affiliation: Cattedra di Medicina Interna, Istituto di Clinica Medica Generale e Terapia Medica IV, Florence, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Tarquini
authors.forename: R
authors.initials: R
authors.lastname: Tarquini
authors.forename: F
authors.initials: F
authors.lastname: Perfetto
authors.forename: G
authors.initials: G
authors.lastname: Cornélissen
authors.forename: F
authors.initials: F
authors.lastname: Halberg
mesh_terms: D002940:Circadian Rhythm; D003920:Diabetes Mellitus / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D020738:Leptin; D008297:Male; D009765:Obesity / Q000235:genetics*; D011506:Proteins / Q000378:metabolism*; D011897:Random Allocation; D012621:Seasons; D012737:Sex Factors; D013997:Time Factors
chemical_list: D020738:Leptin; D011506:Proteins