DDT Clinical Trial
Official title:
Effect of the Antiandrogen DDE on Anthropometric Measures at Birth - Anogenital Distance
Experimental studies have documented the p'p-DDT, p'p-DDE (a metabolite of DDT) and other
organochlorine (OC) compounds have estrogenic and/or antiandrogenic activities capable of
altering normal endocrine functions. It has been postulated that exposure to these toxins
during embriogenesis may cause urogenital malformations. However, this hypothesis has not yet
been evaluated in humans populations with relatively high levels of exposure. The primary
goal of this project is to study in utero exposure to DDE in relation to anogenital distance
in humans. Anogenital distance is measured from a gender and species specific landmark on the
genitalia, such as the junction of the penis and the scrotum in male humans, to the center of
the anus. Altered anogenital distance is a sensitive manifestation of prenatal endocrine
disruption in animal models; whether it is a sensitive endpoint in humans has not been
studied. We will test the hypothesis that DDE, an androgen-receptor blocker, decreases
anogenital distance in male humans who have been chronically but not occupationally exposed
to DDT in Mexico. Study participants will be newborns and their mothers who live in the state
of Chiapas, Mexico and who have been exposed to DDT through house spraying programs to
control malaria in this area. Anogenital distance will be measured at birth and in utero
exposure to DDE will be determined by measuring DDE in maternal blood.
Demonstration that p'p-DDT or p'p-DDE may interfere with normal endocrine functions during
embriogenesis will provide a model to increase our understanding of how other- more
prevalent-environmental estrogens may act and will open new possibilities for research and
potential control of etiologic factors related with this important public health problem....
We propose to follow the women and children enrolled in our original study (n= approximately
850 of each). In the original study, women were enrolled and interviewed while in the
hospital for delivery, their blood was drawn, and anthropometric measurements were performed
on their newborn male infants.
The follow-up will be done primarily to determine the number of months that the mother breast
feeds her child. Secondary endpoints will be infant infection as reported by the mother, and
child growth as determined by measurement of height and weight and related measures (none in
the genital region, as in the original study). Breast feeding duration, infections, and
growth may be related to exposure to the DDT metabolite, DDE.
The follow-up visits will be every three months from 6 to 18 months after birth, and study
nurses will visit subjects in their home. For some subjects, there would be fewer follow-up
visits, due to study scheduling or breastfeeding cessation.
Mothers would be interviewed and mothers and children will undergo standard anthropometric
assessments. This protocol does not call for collection of biologic specimens and poses
minimal risk to subjects.
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