The PEPI study answers key questions about the effects of hormone therapy on bone mineral density. Physicians are increasingly prescribing replacement therapies for the treatment and prevention of osteoporosis. About 25 million people in the U.S. have or are at risk of developing osteoporosis, including 20 percent of women over 50. The increased prevalence of the condition among postmenopausal women is tied to estrogen loss. The hallmark symptom of osteoporosis is low bone mineral density, which leads to an increased risk of fracture.
Fractures can result in serious complications including pain, loss of mobility, and death.
The PEPI study is an important step. BMD in the spine, there were no significant differences in BMD at the hip among women assigned to any of the active therapies. The PEPI trial also found that among those patients who stayed on their therapy for 3 years, combining progestin with estrogen offered no greater benefit in terms of bone mass than taking estrogen alone. Among the patients who adhered to their treatment, between 70 and 90 percent of the increase in BMD occurred during the first year of the study. The remaining 10 to 30 percent increase in bone occurred during the final 2 years.