This month Pediatrics has published 2 articles on environmental chemical exposures that warrant commentary, “Urinary Phthalates and Increased Insulin Resistance in Adolescents” (Trasande et al1 ) and “Bisphenol A and Chronic Disease Risk Factors in US Children” (Eng et al2 ). Both of these articles use the urinary content of the chemical as a surrogate for the chemical exposure.
Dr Trasande and his group in the article on phthalates conclude that urine phthalate concentrations (represented by urine di-2-ethylhexylphthalate [DEHP] concentrations) were associated with increased insulin resistance in this cross-sectional study of adolescents. Dr Trasande refers to this as an association and indicated that this study cannot rule out the possibility that insulin-resistant children ingest food with higher phthalate content or that insulin-resistant children excrete more DEHP. Without knowing the tissue or serum concentration of DEHP or referring to primate studies, the authors’ hypotheses are appropriate.
The second article...