Media Advisory: To contact Diane L. Schneider, M.D., call Kathleen Maher at 619/543-6163.
Continued Estrogen Use Maintains Bone Density in Elderly Women Past estrogen use provides little or no long-term bone benefit
Women who begin estrogen therapy after age 60 can achieve similar bone mineral density (BMD) to women who started taking estrogen at menopause; however, once estrogen is stopped, the benefit disappears, according to an article in this week's issue of The Journal of the American Medical Association (JAMA).
Diane L. Schneider, M.D., from the Department of Medicine at the University of California, San Diego, La Jolla, and colleagues studied 740 white women between the ages of 60 and 98 years to determine the effect of starting point and duration of postmenopausal estrogen replacement therapy on BMD at the ultradistal radius (end of the radius at the wrist), midshaft radius (mid part of the forearm), hip, and lumbar spine (lower back).
The researchers write: "Women who started estrogen during the menopause transition and continued to the present--an average of 20 years--had the best BMD levels at all four sites examined. Current users who started after age 60 years, for an average of only nine years' use, had surprisingly similar BMD levels. Women in their 70s who started estrogen within two years of menopause but stopped it after an average of 10 years had only slightly better bone density than never users."
Compared with never users, current continuous estrogen users had an average 20 percent higher BMD at the ultradistal radius, 12 percent higher BMD at the midshaft radius, eight percent higher BMD at the hip, and 13 percent higher BMD at the lumbar spine. Current late users had similar higher percentages of BMD compared with never users: 19 percent at the ultra radius, 10 percent at the midshaft radius, seven percent at the hip, and 10 percent at the lumbar spine. In contrast, past users had 8-11 percent higher BMD at the ultradistal radius and 2-4 percent higher BMD at the other sites compared with never users.
Of the 740 women in the study, 69 percent had used oral estrogen after menopause and 30 percent were current users. The average current age of those who started estrogen after age 60 years was 78.6 years and their average age at initiation was 68.8 years. Only 45 women started estrogen after age 65 years, of whom 18 were current users. Their mean BMD levels were similar to those starting after age 60 years and were significantly higher than never users.
In the 1970s, exogenous estrogen was observed to reduce postmenopausal bone loss and lower the risk of spinal and extremity fractures. There is, however, little agreement on the optimal time to start or stop estrogen. Concern about breast cancer and other possible risks associated with extended estrogen use and the awareness that bone loss continues or even accelerates in old age have raised questions about when to initiate therapy and whether therapy should be discontinued, according to information cited by the authors.
The researchers state: "Despite these limitations, these data provide some of the strongest evidence to date that estrogen therapy should be continued into late life for the maintenance of high bone density."
They continue: "Estrogen begun after age 60 years appears to offer remarkably similar bone density benefit to estrogen begun in early menopause or after oophorectomy (removal of ovaries), reflecting the skeletal impact of late estrogen use, with increases over two more years followed by reduced rates of loss in the subsequent years. If late continuous use is equivalent to early onset continuous use, estrogen therapy could be initiated at older ages when most osteoporotic fractures occur, reducing the cost and possible risks of long-term estrogen therapy. Further studies of late-onset hormone therapy are indicated."
# For more information:
contact the AMA's Amy Fox at 312/464-4843.
email: [email protected]
AMA web site: http://www.ama-assn.org
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