Study shows estrogen works in the brain to keep weight in check

Study shows estrogen works in the brain to keep weight in check
DALLAS – Oct. 20, 2011 – A recent UT Southwestern Medical Center
study found that estrogen regulates energy expenditure, appetite and
body weight, while insufficient estrogen receptors in specific parts of
the brain may lead to obesity. “Estrogen has a profound effect on metabolism,” said Dr. Deborah Clegg, associate professor of internal medicine and senior author of the study published Oct. 5 in Cell Metabolism. “We hadn’t previously thought of sex hormones as being critical regulators of food intake and body weight.”
The mouse study is the first to show that estrogen, acting through two
hypothalamic neural centers in the brain, keeps female body weight in
check by regulating hunger and energy expenditure. Female mice lacking
estrogen receptor alpha – a molecule that sends estrogen signals to
neurons – in those parts of the brain became obese and developed related
diseases, such as diabetes and heart disease. Similar results
were not seen in male mice, although researchers suspect other unknown
estrogen receptor sites in the brain play a similar role in regulating
metabolism for males as well. Estrogen receptors are located
throughout the body, but researchers found two specific populations of
estrogen receptors that appear to regulate energy balance for female
mice.
Dr. Deborah Clegg
The findings are potentially important for millions of postmenopausal
women, many of whom have decided against hormonal replacement therapy.
The study could lead to new hormonal replacement therapies in which
estrogen is delivered to specific parts of the brain that regulate body
weight, thereby avoiding the risks associated with full-body estrogen
delivery, such as breast cancer and stroke. Doctors stopped
routinely recommending long-term estrogen therapy for menopausal women
in 2002 when a Women’s Health Initiative study showed the hormone also
led to increased risk of cardiovascular disease. “The role of
estrogen in postmenopausal women continues to remain uncertain,” Dr.
Clegg said. “Current research is focused on the timing and the type of
estrogen supplementation that would be most beneficial to women. Our
findings further support a role for estrogens in regulating body weight
and energy expenditure, suggesting a benefit of estrogen supplementation
in postmenopausal women.” Other UT Southwestern researchers
involved in the study included lead author Dr. Yong Xu, a former
postdoctoral researcher in Dr. Clegg’s lab; Dr. Carol Elias, assistant professor of internal medicine; and Dr. Joel Elmquist, professor of internal medicine.
The research was supported by grants from the National Institutes of
Health, the American Heart Association and the American Diabetes
Association. Visit http://www.utsouthwestern.org/nutrition
to learn more about clinical services in nutrition at UT Southwestern,
including treatments for diabetes, kidney disease and obesity.
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Media Contact: Debbie Bolles 214-648-3404 debbie.bolles@utsouthwestern.eduTo automatically receive news releases from UT Southwestern via email,subscribe at www.utsouthwestern.edu/receivenews