Estrogen plus Progestin Effects on Bone Density and the Risk of Fractures

October 2003

Findings Summary

In the October 1 issue of the Journal of the American Medical Association (JAMA), WHI published the final fracture results for the Estrogen plus Progestin (E+P) study. The updated results include information on risk factors for fracture, additional fracture cases, and the bone density results for women in this part of the study.
The updated analysis shows that after an average of 5.6 years, 733 (8.6%) women in the E+P group and 896 (11.1%) women taking placebo (inactive) pills experienced a fracture.
  • Overall, there was a 24% reduction in all fractures and a 33% reduction in hip fractures in women assigned to E+P.
  • Hip bone density increased 3.7% after 3 years of taking E+P compared to 0.14% in the placebo group.
E+P reduced the risk of fracture to a similar degree in women who were considered to be at high or low risk of fracture.
WHI reported in July 2002 that the overall risks of E+P outweighed the benefits, including the fracture benefits. This new report examined whether the balance of risks and benefits, summarized in a global index, differed in women considered to be at high or low risk of fracture. The global index is a number that represents the combined risks and benefits for the major outcomes studied in WHI. There was no evidence of an overall benefit. Even in the group of women at increased risk of fracture, who would benefit most from the prevention of fractures, the risks of E+P outweigh the benefits.
In conclusion, treatment with E+P should not be recommended for the prevention and treatment of osteoporosis in women who don’t have menopausal symptoms. Other medicines for osteoporosis should be considered. If E+P is prescribed to prevent osteoporosis, women need to be informed of the risks of taking E+P.