A new study demonstrates that raloxifene, a selective estrogen receptor modulator (SERM), protects against osteoporosis, while also reducing the blood level of “bad” LDL cholesterol.
A group of researchers from Indiana University, working in collaboration with scientists at Eli Lilly, the drug company which patented and markets raloxifene, published their study in the Dec. 11 issue of the Archives of Internal Medicine. The results support previously published work that shows that raloxifene reverses mineral loss from bone in older women, and also lowers blood cholesterol levels.
They followed two separate groups of post-menopausal women for three years. The total number of study patients was 1,145, and they ranged in age from 45 through 60. The study patients were divided into four separate groups: an inactive placebo control, and those who received raloxifene at doses of 30 milligrams, 60 milligrams or 150 milligrams. They were evaluated every three to six months for bone mineral density (BMD) at the spine, hips and total body; bone metabolism or turnover; and blood lipid (fat and cholesterol) levels.
The results confirmed that raloxifene was effective in slowing, and even reversed, the loss of calcium that leads to the development of osteoporosis. While those receiving the placebo had a diminution in BMD in the lumbar spine of 1.3 percent over the study period, those receiving the active drug at a dose of 30 milligrams had an increase of 0.7 percent, those who received 60 milligrams had an increase of 1.3 percent, and those who received 150 milligrams of raloxifene sustained an increase in their BMD of 1.2 percent. The effects at other skeletal sites were similar. Importantly, there was no increase in serious side effects among those who took raloxifene compared to those who received only placebo. The only difference between the active vs. the placebo groups was in the frequency of hot flashes, which occurred in 25 percent of those on the drug, and in 18 percent of those on placebo.
As for cholesterol levels, those receiving raloxifene had a reduction in total cholesterol of 6 percent to 8 percent, and a reduction in the “bad” cholesterol, LDL, of 7 percent to 12 percent, with the greater reductions associated with the higher dose.
Studies involving estrogen and tamoxifen, a SERM the U.S. Food and Drug Administration approved for the prevention of breast cancer, have shown a higher rate of uterine abnormalities, including cancer, in those taking these prescription drugs without a prescription, probably due to their stimulating effect on the uterine lining cells. While prior studies have not shown that raloxifene has this effect, there were no special evaluations done to assess this problem in this study. No such cases were observed. Also, one preliminary study has shown that raloxifene may exert a protective effect against the development of breast cancer. No analysis for this effect was done in this study. Prior studies have shown that raloxifene might increase the risk of clots in the leg veins, called deep vein thrombophlebitis. There was one such case (out of 860 patients) in the raloxifene group, but this was not felt to be a significant finding.
This study confirms previously reported work showing that raloxifene has a protective effect against osteoporosis, and a beneficial effect on blood cholesterol levels. Prior research has also shown that raloxifene use leads to an actual decrease in bone fractures, a result that this study did not directly address, but which seems likely if BMD rises. Again, the lowered lipid levels may predict a reduced rate of heart disease in those on the drug, but this effect cannot be assumed. There is a major trial now ongoing, the Raloxifene Use for the Heart (RUTH) trial, which is designed to assess this very outcome. There is also a trial underway comparing raloxifene with tamoxifen in the prevention of breast cancer, the STAR trial (Study of Tamoxifen and Raloxifene). The results of both these trials are eagerly awaited to help assess the role of raloxifene in prevention of heart disease and breast cancer. Meanwhile, its place as an agent useful in the prevention and treatment of osteoporosis seems assured at this time.
Raloxifene is called a SERM because it mimics some of the effects of the female hormone estrogen, while opposing other estrogen effects. Raloxifene has been shown to have estrogen-like effects on bone, where both substances tend to protect bone from the loss of calcium that causes osteoporosis. Osteoporosis is a disease common in older women, partially due to lack of estrogen, and is responsible for bone fractures, especially in the spine, hip and forearm.