Research
November 17, 2010
Diapers may yield clues to human development
With the help of babies and more than 5,000 of their diapers, Emory researchers have developed an accurate, noninvasive method to determine estrogen levels in infants.
The method, previously used in nonhuman primates, will allow researchers to learn more about the association between estrogen levels in human infants and their long-term reproductive development as well as the development of sex-specific behaviors, such as toy preference or cognitive differences.
What’s more, the method will also allow researchers to look at how early disruption of the endocrine system affects long-term maturation, a growing concern among researchers and physicians.
Surprisingly little is known about hormone levels during human infancy. Previous human research has focused on the measurement of hormones in blood, urine and saliva.
The new data are the result of using fecal samples collected from cotton diapers. With this novel approach, the researchers successfully measured the fecal levels of estradiol, a type of estrogen.
The well-known importance of estradiol’s role in postnatal development of the body, brain and behavior has in recent years raised specific concerns about how exogenous estrogens, or environmental estrogens, such as those found in soy, fruits and vegetables, plastics and common household items, affect lifelong health.
Leap forward for a real need
“The development of robust, noninvasive methods to measure these hormones in infants allows us to further investigate the association between postnatal hormone production and the development of sex-specific biology and behavior,” says Michelle Lampl, Samuel Candler Dobbs Professor of Anthropology, and senior author of a paper in Frontiers in Systems Biology describing the new method.
The study, conducted by researchers at Emory, the University of North Carolina at Chapel Hill and the University of Virginia Health System, Charlottesville, appears online and in the current issue of Frontiers in Systems Biology.
“The development of an assay to measure estrogen from diapers might initially strike one as unnecessary or strange, but the need is real,” says Sara Berga, James Robert McCord professor and chair of the Department of Gynecology and Obstetrics at Emory School of Medicine.
“We understand very little about the hormonal dynamics that occur during early development precisely because we lack a reliable way to track hormones in neonates and very young children,” Berga notes.
“Having a way to track this critical hormone that influences behavior and the development of many important tissues, including the brain, will allow us to understand normal. This really is a great leap forward, and the investigators should be congratulated on this advance.”
New investigation tool
The study included 32 infants, 15 male and 17 female, aged 7 days to 15 months. The infants’ parents retained soiled diapers after each diaper change during a 24-hour period. Bagged diapers were collected and then frozen and stored at - 80°C and analyzed 24 hours to 12 months after collection. In preparation for analysis, diapers were thawed overnight at 2 to 8°C.
“These observations are the first report of human infant fecal estradiol levels and they provide a new tool for investigating early human development,” says Lampl, who is associate director of the Emory/Georgia Tech Predictive Health Institute. “Because infant diapers are plentiful, fecal samples can be collected frequently and over a long period of time.”
Patricia L. Whitten of Emory is also one of the paper’s authors.
