Update practice on osteoporosis prevention

The next patient in your exam room is in her mid-40s. She notes that her last monthly period was 11 months ago. She continues to use condoms for pregnancy prevention. She has a thin body and a small bone frame, and she smokes 15-20 cigarettes a day. Her medical history indicates a family history of osteoporosis. What is your next move?

Consider use of bone mineral density (BMD) testing for osteoporosis. While routine BMD testing is not recommended for healthy reproductive-age women, testing is appropriate for postmenopausal women older than age 40 who present with other risk factors for fractures.1

Osteoporosis is a key concern for women, particularly as they age. Some 10 million Americans — 80% who are women — have osteoporosis, according to the National Institutes of Health's Osteoporosis and Related Bone Diseases National Resource Center.2 The center estimates that an additional 34 million Americans have low bone mass (osteopenia), placing them at increased risk for osteoporosis and related fractures. One in two women and one in four men older than age 50 can expect to have an osteoporosis-related fracture in their lifetime, according to the center's statistics.2

Risk factors for osteoporosis include: low estrogen levels due to missing menstrual periods or menopause, anorexia nervosa, diet low in calcium and vitamin D intake, long-term use of oral steroids, lack of exercise, smoking, and alcohol use.2 Guidance issued by the World Health Initiative (WHO) defines osteoporosis in women as a BMD value at least -2.5 Standard Deviation (SD) below the mean value of a young healthy population (T-score ≤ -2.5).3

Get ready for updated WHO guidance that will target clinical risk factors in addition to bone mineral density measurements to improve prediction of fracture, says Douglas Bauer, MD, associate professor of medicine, epidemiology, and biostatistics at the University of California San Francisco (UCSF) School of Medicine. The most immediate impact of the WHO report will be a better understanding of the relationship between BMD, risk factors, and the 10-year probability of fracture, says Bauer, who provided an overview at a July 2006 osteoporosis conference sponsored by the university.4 The guidance is expected to be published in 2007. (Editor's note: Watch upcoming issues of Contraceptive Technology Update for coverage.)

"This should help clinicians discuss the risks and benefits of various treatment options, including treatment and watchful waiting," says Bauer. "Eventually the WHO models will be used to construct regional cost-effectiveness models, which might be incorporated into clinical guidelines and influence reimbursement."

What can clinicians do to help patients prevent osteoporosis? Advocate prevention strategies such as: eating a diet rich in calcium and vitamin D, exercising, smoking cessation, and avoidance of excessive alcohol intake.2 Women ages 19-50 should get a daily intake of 1,000 mg of calcium and 200 IU of vitamin D to keep bones strong.2

Medical treatment to reduce risk of fracture should be considered if a woman's BMD is above –2.5 with other risk factors present, such as family history of fracture, a personal history of fracture, low body mass index, smoking, or high bone turnover.1 Family planning clinicians may be most familiar with estrogen-based drug therapies. These include Climara (Berlex Laboratories; Wayne, NJ); Estrace (Warner Chilcott; Rockaway, NJ); Premarin and Prempro (both from Wyeth; Philadelphia), and Estraderm and Vivelle-Dot (both from Novartis Pharmaceuticals; New York City).5

The Women's Health Initiative (WHI) study showed that estrogen/progesterone significantly reduced the risk of hip and vertebral fractures.6 Because the WHI also showed increased risk of vascular side effects and breast cancer,7 estrogen has become a smaller part of osteoporosis prevention and therapy, says Deborah Sellmeyer, MD, an endocrinologist and assistant professor of medicine in residence at UCSF. Its current use centers mostly in the perimenopause and immediate postmenopausal periods for women to relieve such symptoms as hot flashes, observes Sellmeyer, who serves as director of the UCSF/Mount Zion Osteoporosis Center.

What is the role of low-dose and ultra-low dose estrogen formulations in osteoporosis prevention strategies? One example of such therapy is Menostar, a transdermal system from Berlex. Approved by the Food and Drug Administration (FDA in 2004, it delivers 14 mcg of estradiol a day, the lowest dose of products approved for post-menopausal osteoporosis prevention.

Subsequent studies have shown that half the estrogen dose used in the WHI can increase bone density,8 but no fracture data are yet available on any doses or formulations other than the one used in the WHI, says Sellmeyer. No vascular side effects were seen in the studies that looked at low-dose estrogen for bone density, but these studies were much smaller than the WHI, notes Sellmeyer.

Research indicates that low-dose estrogen can increase bone density and help alleviate symptoms of menopause; whether it can prevent fractures is unknown, and whether there is any increased risk of breast cancer or vascular side effects is unknown, Sellmeyer points out. Women and their providers must weigh the risks and potential benefits in using these therapies, she notes.

References

  1. Lindsay R. Perspectives on osteoporosis prevention: How far have we come? OBG Management 2004; 16:3S-9S.
  2. National Institutes of Health. Osteoporosis and Related Bone Diseases National Resource Center. What Is Osteoporosis? Fact sheet. March 2006. Accessed at: www.niams.nih.gov.
  3. World Health Organization (WHO). Assessment of fracture risk and its implication to screening for postmenopausal osteoporosis: Technical report series 843. Geneva: WHO, 1994.
  4. Bauer DC. Who should be treated: Clinical recommendations and guidelines for treatment. Presented at Osteoporosis: New Insights in Research, Diagnosis and Clinical Care. San Francisco, July 2006.
  5. National Institutes of Health. Osteoporosis and Related Bone Diseases National Resource Center. Medications to Prevent and Treat Osteoporosis. May 2006. Accessed at niams.nih.gov.
  6. Cauley JA, Robbins J, Chen Z, et al, for the Women's Health Initiative Investigators. Effects of estrogen plus progestin on risk of fracture and bone mineral density: The Women's Health Initiative randomized trial. JAMA 2003; 290:1,729-1,738.
  7. Rossouw JE, Anderson GL, Prentice RL, et al; Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: Principal results from the Women's Health Initiative randomized controlled trial. JAMA 2002; 288:321-33.
  8. Ettinger B, Ensrud KE, Wallace, R, et al. Effects of ultralow-dose transdermal estradiol on bone mineral density: A randomized clinical trial. Obstet Gynecol 2004; 104:443-451.