title: Racial variation in umbilical cord blood leptin concentration in male babies.
abstract: BACKGROUND
  We hypothesize that racial differences in utero contribute to the racial disparity in prostate cancer risk. Leptin is a candidate for evaluating this hypothesis because it influences fetal development and newborn growth.
  
  
  METHODS
  We measured leptin concentration by ELISA in venous cord blood collected from 70 African-American and 37 white male full-term babies. We measured sex steroid hormones and insulin-like growth factor (IGF) axis concentrations previously. Separately by race, we calculated the geometric mean leptin concentration and estimated the geometric mean adjusted for birth and placental weights, mother's age and parity, time of day and season of birth, and sex steroid hormone and IGF axis concentrations by linear regression.
  
  
  RESULTS
  Leptin was positively correlated with birth (r = 0.34) and placental (r = 0.25) weights, IGF-1 (r = 0.21), and IGF binding protein-3 (r = 0.29) adjusting for race. Unadjusted geometric mean leptin did not differ (P = 0.92) between African Americans (5,280 pg/mL; 95% CI: 4,322-6,451) and whites (5,187 pg/mL; 95% CI: 3,938-6,832). Adjusted geometric mean leptin was nonstatistically significantly higher (P = 0.15) in African Americans (5,954 pg/mL; 95% CI: 4,725-7,502) than in whites (4,133 pg/mL; 95% CI: 2,890-5,910).
  
  
  CONCLUSIONS
  We observed a nonsignificantly higher adjusted cord blood leptin concentration in African-American male babies than in white male babies, although unadjusted levels were similar.
  
  
  CONCLUSIONS
  These findings do not support the hypothesis that leptin level in utero contributes to the racial disparity in prostate cancer risk in adulthood.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Gabriel Y
authors.initials: GY
authors.lastname: Lai
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
authors.forename: Tanya
authors.initials: T
authors.lastname: Agurs-Collins
authors.forename: Catherine G
authors.initials: CG
authors.lastname: Sutcliffe
authors.forename: Gary
authors.initials: G
authors.lastname: Bradwin
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Bienstock
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Platz
mesh_terms: D001741:Black or African American; D004797:Enzyme-Linked Immunosorbent Assay; D005006:Ethnicity; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D020738:Leptin / Q000097:blood*; D008297:Male; D011247:Pregnancy; D011471:Prostatic Neoplasms / Q000097:blood / Q000208:ethnology; D012737:Sex Factors; D044465:White People
chemical_list: D020738:Leptin