The study involved 373 women ages 65 to 90 who had either thinning bones or full-blown osteoporosis and took one of four treatments for three years: hormones combined with alendronate, sold as Fosamax; hormones alone; Fosamax alone; or dummy pills.
Last summer, a study was published linking hormone supplements with heart attacks, strokes and breast cancer.
But the incidence of those problems was extremely low in the new study, said lead author Dr. Susan Greenspan, professor of medicine at the University of Pittsburgh. The hormones-Fosamax treatment "was safe and well-tolerated," said Greenspan, who has worked as a consultant for Fosamax maker Merck Research Laboratories.
Greenspan said her study suggests the hormones-Fosamax treatment may be an option for older women who face a severe risk of osteoporosis and bone fractures.
The findings appear in Wednesday's Journal of the American Medical Association.
The hormone study released last summer, the Women's Health Initiative, led many doctors to recommend against using hormone supplements for any reason other than relief of short-term menopause symptoms. And a WHI researcher, Jennifer Hays, said the new findings are not convincing enough to recommend hormones for osteoporosis prevention even in older women.
Hays, a Baylor College of Medicine psychologist, said the bone-enhancing benefits from estrogen come only after long-term use - which also carries the highest risk of breast cancer or heart disease.
The hormones used in the Fosamax study contained estrogen alone or estrogen-progestin.
After three years, hipbone density had increased nearly 6 percent in women on hormones plus Fosamax, 4 percent in those on Fosamax, and 3 percent in the hormones-only group. Increases also were seen in spinal bone density.
Higher bone density is usually associated with fewer fractures.
By Lindsey Tanner