Corinna Kaarlela, Interim News Director
Source: Jennifer OÃBrien (415) 476-2557
EMBARGOED FOR RELEASE: 3 P.M. (CENTRAL TIME), SUNDAY, DECEMBER 7, 1997 TO COINCIDE WITH PUBLICATION IN ARCHIVES OF INTERNAL MEDICINE
PLANT-BASED ESTROGEN SHOWN TO PREVENT OSTEOPOROSIS AT HALF STANDARD DOSE, WITH FEWER SIDE EFFECTS
An estrogen derived from plants was shown in clinical trials to prevent osteoporosis at half the dose of the animal-based estrogen normally prescribed by physicians--and with fewer side effects--according to a new study.
Results are published today in Archives of Internal Medicine.
In the paper, researchers led by a University of California San Francisco scientist report that low dose, plant-based estrogen did not cause the increase in vaginal bleeding or endometrial hyperplasia, a precursor to endometrial cancer, associated with the traditional animal-based therapy given at a higher dose. Nor did the low dose, plant-based estrogen cause as great an increase in breast tenderness, headaches or nausea as the standard treatment.
The estrogen used in the study also brought relief from such menopausal symptoms as hot flashes and night sweats.
The finding has potentially significant implications for the preventive treatment of osteoporosis and heart disease in post-menopausal women, according to UCSF lead author Harry K. Genant, MD, director of the Osteoporosis Research Group at UCSF, as it diminishes risks and could increase compliance with drug treatment.
The majority of women who start estrogen-replacement therapy quit within one or two years due to side effects, thereby preventing the long-term protective effects of estrogen on bone and cardiovascular health.
"Estrogen is first-line therapy for osteoporosis prevention," says Genant. "Yet to be beneficial, long-term use is needed. Many women drop out of therapy after a short time because they donÃt like the side effects."
The two-year, multi-center study was double-blind, and involved 406 post-menopausal women. Results showed that women taking doses of esterified (plant-based) estrogen with a daily supplement of 1,000 milligrams of calcium, a standard component of estrogen therapy, showed increased bone mineral density in the spine, hip and whole body. Patients receiving placebo continued to lose bone mineral density.
Study participants received esterified estrogen in tablet form as the drug product Estratab.
Estrogen replacement therapy is intended to compensate for the fact that during menopause the ovaries stop producing estrogen. The loss of estrogen leads to an accelerated loss of bone, placing women at risk for disabling fractures and osteoporosis. It also increases the risk of heart disease, due to a potential increase in LDL blood cholesterol levels, coronary spasms and stiffer arteries.
The typical dose of estrogen for the prevention of osteoporosis has been 0.625 milligrams daily of an animal-based estrogen. Previous studies of women taking 0.3 milligrams doses of this animal-based estrogen have been inconclusive to date at demonstrating bone preservation.
The new study, on the other hand, demonstrates conclusively that plant-based estrogens at a daily dose of 0.3 milligrams have a statistically significant impact on bone preservation, says Genant.
"As with most medications, the lower the dose, the fewer the side effects," he says.
"The results of this study may not apply to conjugated equine estrogens," says Genant.
The study also suggests the possibility of a reduced therapeutic role for the hormone progestin, a complementary component of estrogen replacement therapy in women with an intact uterus. The hormone, given to offset the risk of endometrial cancer, may not be needed, or may be required at a lower dose, with the low-dose, plant-based estrogen therapy, says Genant.
"The minimal side effects on the endometrium associated with the low dose, plant-based estrogen suggest that elimination or less frequent or lower dose progestin use may be possible," says Genant. However, as the findings are only valid through two years of observation, he says, larger and longer studies are needed first.
Reducing levels of progestin could be beneficial, as progestin often causes undesirable side effects, including bleeding, breast tenderness and pain, bloating, cramps and depression.
In a related paper analyzing the same data, medical researchers elsewhere also reported that plant-based estrogen did not result in a higher incidence of vaginal bleeding. The paper appeared in the September issue of Menopause: The Journal of the North American Menopause Society.
"Overcoming vaginal bleeding will help improve compliance considerably," says Wulf Utian, MD, director of the North American Menopause Society. "Many women refuse or discontinue estrogen replacement therapy because of breakthrough bleeding at a time of life when that should no longer be a matter of concern."
Osteoporosis currently affects more than 28 million Americans, 80 percent of whom are women. It is estimated that one of every two women over the age of 50 will have an osteoporosis-related fracture in her lifetime. An estimated 50,000 people die each year following fracture-related complications. The direct medical costs of osteoporosis approach $13.8 billion annually.
The study was supported by Solvay Pharmaceuticals Inc., Marietta, Georgia, makers of Estratab.
Note to media:
To arrange an interview with Harry K. Genant, MD, contact Jennifer OÃBrien in the UCSF News Office, at 415/476-2557.
B-roll containing sound bites of Harry K. Genant, MD, is available via satellite feed. To arrange access, contact at Fleishman Hillard Inc.: Russell Grant, 212/453-2430 or Beverly Greenfield, 212/453-2452.
For information on Estratab, contact at Solvay Pharmaceuticals Inc.: Karen Kaplan, 770/578-5637.
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