----------------------------------------------------------------------- Low-dose estrogen therapy seen protecting women's bones after menopause ----------------------------------------------------------------------- CHICAGO (December 8, 1997 10:41 a.m. EST http://www.nando.net) -- Half the usual dose of estrogen given to women after menopause was sufficient to protect their bones from thinning and brought on fewer unpleasant side effects, researchers found. The low dose also had favorable effects on cholesterol and other fats circulating in the blood, suggesting its potential for protecting postmenopausal women from heart disease might also be significant, researchers said. Protection from bone thinning and heart disease are major benefits of higher-dose estrogen replacement therapy over the long term. But many women are leery of estrogen therapy because studies suggest it may increase breast cancer risk. And many women who begin hormone therapy for relief of menopausal hot flashes and other symptoms quit in a year or two because of side effects, said the lead researcher, Dr. Harry K. Genant of the University of California, San Francisco. Low-dose estrogen in the study caused less breast tenderness, headaches and nausea than the standard higher-dose treatment does, and it could be expected to pose less risk of breast cancer, Genant said. The study of 406 women is published in the December issue of the American Medical Association's Archives of Internal Medicine, released Sunday. A related study in the journal found that alendronate, a non-hormonal drug used to fight osteoporosis, was highly effective at reducing the risk of spinal fractures even in very old and severely osteoporotic patients. That study involved 2,027 women aged 55 to 81 and was led by Dr. Kristine E. Ensrud of the Veterans Affairs Medical Center in Minneapolis. The study was supported by Merck Research Laboratories of Rahway, N.J., a division of Merck and Co., which makes alendronate under the brand name Fosamax. A researcher not involved in either study, Dr. Michael Maricic of Arizona Health Sciences Center in Tucson, said both resulted in important findings. "It may be possible to prevent osteoporosis with lower, safer doses of estrogen, and if prevention is no longer possible, it is never too late to treat," Maricic said. Osteoporosis afflicts an estimated 10 million Americans, mostly elderly women, and the fractures it causes cost an estimated $13.8 billion in U.S. health care expenditures in 1995. In the two-year study led by Genant, postmenopausal women taking only 0.3 milligram of estrogen showed no loss of bone mass and some even had a slight increase. The usual dose of estrogen for preventing osteoporosis is 0.625 milligram. The low-dose subjects took the hormone with 1,000 milligrams of supplemental calcium daily. Standard higher dose estrogen therapy is also supplemented with calcium and combined with the female hormone progestin to offset estrogen's tendency to promote cancer of the uterine lining. The most commonly used estrogen drugs, of which the best-known brand is Premarin, are derived from animal and synthetic sources and are approved for use in preventing and treating osteoporosis. The estrogen used in the low-dose study is derived from plants and not approved for treating osteoporosis. Its best-known brand is Estratab. Genant said results of the study, conducted at 29 medical centers and financed by Estratab manufacturer Solvay Pharmaceuticals Inc. of Marietta, Ga., would be submitted to the Food and Drug Administration in an application for approval to treat osteoporosis as well as menopausal symptoms. Doctors may prescribe drugs for purposes other than approved ones, but manufacturers may not promote them for those purposes. "We have another very attractive alternative for a woman postmenopausally who is concerned about the potential for osteoporosis, the potential for cardiovascular disease, but is (also) concerned about taking the usually higher doses of estrogen," Genant, director of the Osteoporosis Study Group at his school, said in a telephone interview Friday. In the study, no progestin was used, but with 0.3-milligram estrogen doses, researchers found no cancerous changes in the uterine linings of subjects. Larger and longer studies would be needed to verify the safety of taking low-dose estrogen alone for more than two years, Genant said. Such a prospect would be attractive, because progestin causes intermittent vaginal bleeding in most women and depression or irritability in some. By BRENDA C. COLEMAN, AP Medical Writer Copyright 1997 Nando.net Copyright 1997 The Associated Press http://www.nando.net/newsroom/ntn/health/120897/health34_16_noframes.html ----------------------------------------------------------------------- janet [log in to unmask]