EMBARGOED
FOR RELEASE UNTIL
August 8, 2007
APS Contact
Donna Krupa
Office:
(301) 634-7253
Cell: (703) 967-2751
dkrupa@the-aps.org
Study Suggests Estrogen
Deficiency Can Lead To Obesity-Induced
High Blood Pressure Following Menopause
Austin, TX – At menopause, women lose hormone
protection against heart (cardiovascular) and kidney (renal) diseases, and
are likely to become obese. A research team has tested the idea that
estrogen deficiency in aged females may trigger the development of high
blood pressure and obesity. The results of their study, using an animal
model, suggest that estrogen depletion can have these effects.
The study is entitled, “Role of Estrogens in
Postmenopausal Obesity and Hypertension.” It was conducted by Lourdes A.
Fortepiani and Huimin Zhang, University of Texas Health Science Center at
San Antonio (UTHSCSA), San Antonio, TX. The team will discuss its findings
as part of the upcoming conference, Sex and Gender in
Cardiovascular-Renal Physiology and Pathophysiology, being held August
9-12, 2007 at the Hyatt Regency Austin on Town Lake in Austin, TX. The event
is the second scientific gathering to be sponsored by the American
Physiological Society (APS;
www.The-APS.org) this year.
To test their theory the researchers used 24 aged
female rats. The ovaries were removed from two-thirds of the group (ovariectomized;
ovx) while the ovaries of the other third of the group remained intact and
served as controls. The researchers subdivided the ovx rats, giving half of
the ovx group estrogen while the other half remained estrogen depleted.
Among the ovx rats, those that did not receive estrogen
had significantly higher blood pressure than the control rats (126.2 versus
110.6 mmHg). The rats receiving estrogen had the lowest blood pressure
levels of all (102.6 mmHg).
The researchers also noted that the rats which had
their ovaries removed and did not receive estrogen compared to the intact
rats
-
gained twice as much weight as the controls
-
increased their leptin level by 70 percent
-
increased their blood glucose level by 35 percent
-
increased RAS and renal SNS by 16 and 39 percent
-
experienced no change in kidney function
All the hormonal and metabolic effects were completely
abolished with estrogen replacement. In other words, the rats whose ovaries
were removed and received estrogen replacement did not undergo any of the
changes mentioned above.
With increased life expectancy, women spend more than a
third of their life in menopause. In addition, obesity is increasing
dramatically in all populations and is a major cardiovascular risk factor in
women after menopause. Despite the
controversial data about estrogen therapy in clinical studies, the results
of this study performed in aged rats suggest that the loss of estrogens
after menopause may contribute to the development of obesity and
hypertension, opening new therapeutic approaches to postmenopausal
hypertension.
***
The
American Physiological Society (APS;
www.The-APS.org) has been an integral part of the scientific discovery
process since it was established in 1887. Physiology is the study of
how molecules, cells, tissues and organs function to create health or
disease.
# # #
NOTE TO EDITORS: The APS meeting is being held
August 9-12, 2007 at the Hyatt Regency Austin on Town Lake, Austin, TX.
Members of the media are invited to attend the sessions. To schedule an
interview with Dr. Fortepiani, please contact Donna Krupa at
301.634.7209 (direct dial), 703.967.2751 (cell) or
DKrupa@the-APS.org. |
