Prenatal concentrations of polychlorinated biphenyls, DDE, and DDT and overweight in children: a prospective birth cohort study.
BACKGROUND
Recent experimental evidence suggests that prenatal exposure to endocrine-disrupting chemicals (EDCs) may increase postnatal obesity risk and that these effects may be sex or diet dependent.


OBJECTIVE
We explored whether prenatal organochlorine compound (OC) concentrations [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT)] were associated with overweight at 6.5 years of age and whether child sex or fat intakes modified these associations.


METHODS
We studied 344 children from a Spanish birth cohort established in 1997-1998. Overweight at 6.5 years was defined as a body mass index (BMI) z-score ≥ 85th percentile of the World Health Organization reference. Cord blood OC concentrations were measured and treated as categorical variables (tertiles). Children's diet was assessed by food frequency questionnaire. Relative risks (RRs) were estimated using generalized linear models.


RESULTS
After multivariable adjustment, we found an increased RR of overweight in the third tertile of PCB exposure [RR = 1.70; 95% confidence interval (CI): 1.09, 2.64] and the second tertile of DDE exposure (RR = 1.67; 95% CI: 1.10, 2.55), but no association with DDT exposure in the population overall. Associations between overweight and PCB and DDE concentrations were strongest in girls (p-interaction between 0.01 and 0.28); DDT was associated with overweight only in boys. For DDT we observed stronger associations in children with fat intakes at or above compared with below the median, but this interaction was not significant (p-interaction > 0.05).


CONCLUSIONS
This study suggests that prenatal OC exposures may be associated with overweight in children and that sex and high-fat intake may influence susceptibility.
Centre for Research in Environmental Epidemiology, Barcelona, Spain. dvalvi@creal.cat
Damaskini
D
Valvi
Michelle A
MA
Mendez
David
D
Martinez
Joan O
JO
Grimalt
Maties
M
Torrent
Jordi
J
Sunyer
Martine
M
Vrijheid
D000328:Adult; D015992:Body Mass Index; D002648:Child; D002849:Chromatography, Gas; D015331:Cohort Studies; D003634:DDT / Q000097:blood / Q000633:toxicity; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood / Q000633:toxicity; D004041:Dietary Fats / Q000633:toxicity*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006581:Hexachlorobenzene / Q000097:blood / Q000633:toxicity; D006801:Humans; D008297:Male; D009765:Obesity / Q000139:chemically induced / Q000453:epidemiology / Q000209:etiology; D050177:Overweight / Q000139:chemically induced / Q000453:epidemiology* / Q000209:etiology*; D010575:Pesticides / Q000097:blood / Q000633:toxicity*; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000633:toxicity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology
D004041:Dietary Fats; D010575:Pesticides; D003633:Dichlorodiphenyl Dichloroethylene; D006581:Hexachlorobenzene; D003634:DDT; D011078:Polychlorinated Biphenyls