Insulin-like growth factor-I (IGF-I) serum concentrations in healthy children and adolescents: Relationship to level of contamination by DDT-derivative pesticides

Abstract

Context: Serum levels of Insulin-like growth factor I (IGIF-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 and design: 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 (6-15 years) who showed detectable Values of p,p'-DDE, and p,p'-DDD than in pre-pubertal male children with undetectable levels of these OC-DDT's-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 prepubertal male children (6-15 years; p = 0.043).Conclusion: 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. (C) 2009 Elsevier Ltd. All rights reserved.