title: Leptin resistance is associated with extreme obesity and aggregates in families.
abstract: OBJECTIVE
  To examine the determinants of plasma leptin levels and leptin resistance in a sample of extremely obese subjects and their relatives.
  
  
  METHODS
  We obtained plasma leptin values on 968 individuals from 218 families having both extremely obese and average weight members for obesity related variables. Multivariate regression analyses were used to identify predictors of both plasma leptin concentration and an index of leptin resistance. Family correlations and heritabilities were computed for plasma leptin and indices of leptin resistance.
  
  
  RESULTS
  Body mass index and sex predicted 63% of the variance in plasma leptin. Extremely obese subjects were most likely and average weight subjects least likely to be leptin resistant. Both leptin and leptin resistance aggregated within families.
  
  
  CONCLUSIONS
  Leptin resistance is strongly associated with extreme obesity and appears to be a heritable trait. The determination of its genetic causes will aid in understanding the role of leptin in common forms of human obesity.
authors.affiliation: Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: D R
authors.initials: DR
authors.lastname: Reed
authors.forename: R A
authors.initials: RA
authors.lastname: Price
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D020738:Leptin / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000235:genetics*; D010641:Phenotype; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D020738:Leptin