RESUMEN
BACKGROUND: In utero exposure to endocrine disrupting compounds including dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) has been hypothesized to increase risk of obesity later in life. OBJECTIVES: The Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study is a longitudinal birth cohort of low-income Latinas living in a California agricultural community. We examined the relation of in utero DDT and DDE exposure to child obesity at 7 years of age. We also examined the trend with age (2, 3.5, 5, and 7 years) in the exposure-obesity relation. METHODS: We included 270 children with o,p´-DDT, p,p´-DDT, and p,p´-DDE concentrations measured in maternal serum during pregnancy (nanograms per gram lipid) and complete 7-year follow-up data including weight (kilograms) and height (centimeters). Body mass index (BMI; kilograms per meter squared) was calculated and obesity was defined as ≥ 95th percentile on the sex-specific BMI-for-age Centers for Disease Control and Prevention 2000 growth charts. RESULTS: At 7 years, 96 (35.6%) children were obese. A 10-fold increase in o,p´-DDT, p,p´-DDT, or p,p´-DDE, was nonsignificantly associated with increased odds (OR) of obesity [o,p´-DDT adjusted (adj-) OR = 1.17, 95% CI: 0.75, 1.82; p,p´-DDT adj-OR = 1.19, 95% CI: 0.81, 1.74; p,p´-DDE adj-OR = 1.22, 95% CI: 0.72, 2.06]. With increasing age at follow-up, we observed a significant trend toward a positive association between DDT and DDE exposure and odds of obesity. CONCLUSION: We did not find a significant positive relation between in utero DDT and DDE exposure and obesity status of 7-year-old children. However, given the observed trend with age, continued follow-up will be informative.
Asunto(s)
DDT/toxicidad , Diclorodifenil Dicloroetileno/toxicidad , Feto/efectos de los fármacos , Obesidad/inducido químicamente , Efectos Tardíos de la Exposición Prenatal , Niño , Estudios de Cohortes , DDT/sangre , Diclorodifenil Dicloroetileno/sangre , Femenino , Humanos , Estudios Longitudinales , Americanos Mexicanos , EmbarazoRESUMEN
BACKGROUND: Epidemiologic studies suggest that maternal organophosphorus (OP) pesticide exposure is associated with poorer fetal growth, but findings are inconsistent. We explored whether paraoxonase (PON1), a key enzyme involved in detoxification of OPs, could be an effect modifier in this association. METHODS: The study population included 470 pregnant women enrolled in the CHAMACOS Study, a longitudinal cohort study of mothers and children living in an agricultural region of California. We analyzed urine samples collected from mothers twice during pregnancy for dialkyl phosphate (DAP) metabolites of OP pesticides. We analyzed maternal and fetal (cord) blood samples for PON1 genotype (PON1(192) and PON1(-108)) and enzyme activity (paraoxonase and arylesterase). Infant birth weight, head circumference, and gestational age were obtained from medical records. RESULTS: Infants' PON1 genotype and activity were associated with birth outcome, but mothers' were not. Infants with the susceptible PON1(-108TT) genotype had shorter gestational age (ßâ=â-0.5 weeks, 95% Confidence Interval (CI): -0.9, 0.0) and smaller head circumference (ßâ=â-0.4 cm, 95% CI: -0.7, 0.0) than those with the PON1(-108CC) genotype. Infants' arylesterase and paraoxonase activity were positively associated with gestational age. There was some evidence of effect modification with DAPs: maternal DAP concentrations were associated with shorter gestational age only among infants of the susceptible PON1(-108TT) genotype (p-value(interaction)â=â0.09). However, maternal DAP concentrations were associated with larger birth weight (p-value(interaction)â=â0.06) and head circumference (p-value(interaction)<0.01) in infants with non-susceptible genotypes. CONCLUSIONS: Infants whose PON1 genotype and enzyme activity levels suggested that they might be more susceptible to the effects of OP pesticide exposure had decreased fetal growth and length of gestation. PON1 may be another factor contributing to preterm or low birth weight birth.