title: Insulin-like growth factor-I (IGF-I) serum concentrations in healthy children and adolescents: relationship to level of contamination by DDT-derivative pesticides.
abstract: BACKGROUND
  Serum levels of Insulin-like growth factor I (IGF-I) play a critical role in children growth and in the pathogenesis of several diseases. In addition, recent studies suggest that DDT-derivative organochlorine pesticides (OC-DDTs) could influence IGF levels in human beings.
  
  
  OBJECTIVE
  Because it has been suggested that IGF-I peak levels at puberty could determine IGF-I levels in adulthood, we developed a cross-sectional study of the potential association between serum levels of OC-DDTs and IGF system in 160 serum samples from young people (81 boys and 79 girls) living in the Canary Islands (Spain).
  
  
  RESULTS
  Multivariate tests were used adjusting for confounding variables (age, height, and weight) and stratifying by gender and age: IGF-I serum levels were significantly lower in pre-pubertal male children (6-15years) who showed detectable values of p,p'-DDE, and p,p'-DDD than in pre-pubertal male children with undetectable levels of these OC-DDTs-metabolites (p=0.023 and p=0.049, respectively). In addition, in this multivariate model, a non-linear dose-response curve was observed between Total DDT body burden (sum of the three DDT-derivatives measured: p,p'-DDT, p,p'-DDE, and p,p'-DDD) and IGF-I in pre-pubertal male children (6-15years; p=0.043).
  
  
  CONCLUSIONS
  These findings suggest that OC-DDTs could modulate the IGF-system in a way that is highly influenced by gender and age. Improvements in our understanding of exogenous determinants of the IGF-system may provide new insights into the role played by environmental contaminants in IGF-related diseases.
authors.affiliation: Toxicology Unit, Department of Clinical Sciences, University of Las Palmas de Gran Canaria and Instituto Canario de Investigación del Cáncer (ICIC), P.O. Box 550, 35080 Las Palmas de Gran Canaria, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Zumbado
authors.forename: Octavio P
authors.initials: OP
authors.lastname: Luzardo
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Lara
authors.forename: Eva E
authors.initials: EE
authors.lastname: Alvarez-León
authors.forename: Antonio
authors.initials: A
authors.lastname: Losada
authors.forename: Rosa
authors.initials: R
authors.lastname: Apolinario
authors.forename: Lluis
authors.initials: L
authors.lastname: Serra-Majem
authors.forename: Luis D
authors.initials: LD
authors.lastname: Boada
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001827:Body Height / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002648:Child; D003430:Cross-Sectional Studies; D003634:DDT / Q000097:blood* / Q000633:toxicity; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D010573:Pesticide Residues / Q000097:blood* / Q000633:toxicity; D011627:Puberty / Q000097:blood / Q000187:drug effects; D013030:Spain
chemical_list: D004785:Environmental Pollutants; D018972:Insulin-Like Growth Factor Binding Protein 3; D010573:Pesticide Residues; D003633:Dichlorodiphenyl Dichloroethylene; D007334:Insulin-Like Growth Factor I; D003634:DDT