Exposure to organochlorine compounds during pregnancy may increase the risk of overweight in children at 6 years of age
17/09/2012
In recent decades it has been observed in several countries a dramatic increase in obesity not only in adults but also in children. Spain currently has one of the highest rates of childhood obesity in Europe with approximately 30{3effe4377b6f02be2524d084f7d03914ac32a2b62c0a056ca3444e58c1f10d0b} of overweight children. Recently, animal studies suggest that prenatal exposure to organochlorine compounds such as polychlorinated biphenyls (PCBs), the dichlorodiphenyl trichloroethane (DDT) and its metabolite dichlorodiphenyl dichloroethane (DDE) may increase the risk of developing obesity child. The production and use of DDT in agriculture and PCBs in industrial processes were intensive after the ’30s. Its use is currently prohibited or restricted in developed countries, however, these compounds are still present in the environment due to its slow biodegradation and their use in developing countries. In humans the majority exposure route is through the high-fat diet. The evidence in humans of exposure to organochlorine compounds during pregnancy and increased risk of obesity in children is very limited. Therefore, in this study we evaluated the association between exposure to organochlorine compounds during pregnancy and overweight at age 6 years in children INMA cohort in the island of Menorca.
Concentrations of PCBs, DDT and DDE were measured in cord blood samples that were collected from the mothers participating in the cohort of Menorca at the time of delivery. We calculate the body mass index (BMI) (weight / height ²) using anthropometric measurements of children who performed the research staff of INMA when the child was age 6 years. To define overweight children use specific cutoff points for age and sex of each child recommended by the World Health Organization in 2007 (BMI greater than or equal to the 85th percentile). We studied the association between prenatal exposure to organochlorine compounds and overweight child by statistical models.
The results of this study showed that exposure during pregnancy to PCBs and DDE is associated with an increased risk of overweight in children at the age of 6 years. The estimated risk was higher in girls than in boys. Exposure to DDT during pregnancy is associated with overweight at age 6 years only in boys but not girls. The association between exposure to DDT and child overweight was also lighter in children with a high fat intake compared with children with lower fat intake.
In conclusion, the present study provides evidence that exposure during pregnancy to organochlorine compounds may increase the risk of overweight in children at the age of 6 years. Sex and high fat intake by the child potentially influence this association.
Dania Valvi is graduated in Medicine and Master of Public Health. She is currently completing a PhD in Biomedicine at the University Pompeu Fabra.