Body mass index in young school-age children in relation to organochlorine compounds in early life: a prospective study

OBJECTIVE: To investigate the association between maternal pregnancy and estimated postnatal serum concentrations of the organochlorines 2,2', 4,4', 5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p, p'-DDE) and body mass index (BMI) z-scores in 5- to 9-year-old children. METHODS: Maternal sera from the INUENDO birth cohort (2002-2004) comprising mother-child pairs (N = 1109) from Greenland, Warsaw (Poland), and Kharkiv (Ukraine) were analysed for CB-153 and p, p'-DDE, using gas chromatography-mass-spectrometry, and were grouped into tertiles for statistical analyses. A toxicokinetic model was used to estimate the first 12 months cumulative exposure to the compounds. Associations between these compounds and child age-and sex-specific BMI z-scores were calculated at follow-up (2010-2012), using multiple linear regression analysis. RESULTS: No clear associations between pregnancy CB-153 and p, p'-DDE and child BMI were observed (the pooled differences in BMI z-score (95% confidence interval) comparing 3rd tertile to 1st tertile were -0.07 (-0.32 to 0.18) and -0.10 (-0.30 to 0.10) kg m(-2), respectively). For postnatal CB-153 and p, p'-DDE and BMI, the overall differences in BMI z-score comparing 3rd tertile to 1st tertile were 0.12 (-0.15 to 0.39) and -0.03 (-0.20 to 0.27) k gm(-2), respectively. CONCLUSIONS: This follow-up study of Greenlandic, Polish and Ukrainian populations showed no clear association between pregnancy and postnatal exposure to p, p'-DDE and CB-153 and BMI at the age of 5-9 years.