A new study by researchers at the University of California, Los Angeles has determined that while hormone replacement therapy may strengthen bones in women after menopause, this benefit may be limited-for up to three years. Thereafter, according to their findings, the effect may be minimal.
Furthermore, according to Dr. Gail Greendale and colleagues, women who then stop taking HRT do not lose bone density any faster than women who never took HRT in the first place.
Writing in the Archives of Internal Medicine, the researchers reported on their three-year study of nearly 500 postmenopausal women who stopped HRT either before or after the study period, and compared these women to a similar number who did not use HRT. Specifically, they measured bone mineral density in the hip and spine over the three-year study period and again four years later after the study ended.
They found that the women who used HRT gained about 3 percent bone mineral density in the spine and 1.5 percent in the hip in the first year, with smaller gains in the second and third years. Thereafter, however, they did not find any measurable gain or loss in bone density in women who continued to take HRT after the three-year mark.
For women who discontinued the use of HRT, their subsequent rate of bone loss was equivalent to women who had never used HRT-approximately 1 percent in the first year and about half that much in each subsequent year.
"Our results do not support the hypothesis that bone is lost at an unusually fast rate after discontinuation of HRT," they wrote. "Nor do they suggest that longer-term HRT leads to additional bone mineral density gain beyond that evident after 3 years."
The researchers said their findings are important for women who may be at higher risk for breast cancer and fear that long-term use of HRT may further increase their risk. However, they cautioned that studies to date have been inconclusive regarding the link between long-term use of HRT and an increased risk of breast cancer.
SOURCE:
Archives of Internal Medicine, March 25, 2002; 162:665-672
