Update on Osteoporosis

Because the low bone mass and deterioration of bone microarchitecture and quality that characterize osteoporosis can lead to fragility fracture, it is vital that we intervene in our patients’ health in a timely manner to reduce this risk. One way to accomplish this goal is to understand the role of age in determining a woman’s fracture risk. For example, an 80-year-old woman and a 50-year-old woman with a T-score of –2.5, as measured by dual x-ray absorptiometry (DXA), will have dramatically different fracture risks. According to the World Health Organization’s fracture-risk assessment tool (http://www.shef.ac.uk/FRAX/), the older woman has a 10-year probability of hip fracture approximately five times greater than the younger woman.

Although no new therapies have been approved during the past year, several important findings were published that affect clinical management of menopausal patients or suggest changes likely in the future.

In this article, I review:

• the latest guidance on osteoporosis from the American College of Obstetricians and Gynecologists (ACOG)
• the most recent indications for bone mineral density (BMD) testing from the International Society for Clinical Densitometry (ISCD)
• a study exploring the effect of oral hormonal contraception on the acquisition of peak BMD in adolescents and young women
• results of a randomized trial of the experimental agent odanacatib in postmenopausal women
• a pilot study of teriparatide (Forteo) for idiopathic osteoporosis in premenopausal women.

ACOG ISSUES RECOMMENDATIONS ON SCREENING, TREATMENT, AND LIFESTYLE

Committee on Practice Bulletins–Gynecology. ACOG Practice Bulletin #129: Osteoporosis. Obstet Gynecol. 2012;120(3):718–734.

This comprehensive review of management guidelines for ObGyns deserves “top billing” in this update. It offers recommendations on important interventions, from BMD measurement and subsequent monitoring to calcium and vitamin D supplementation.

When to initiate screening

• Begin BMD screening using DXA at age 65. DXA also may be appropriate for younger women if they are postmenopausal and have other significant risk factors for osteoporosis or fracture (Level A evidence – based on good and consistent scientific evidence).
• In the absence of new risk factors, do not perform DXA screening more frequently than every 2 years (Level B evidence – based on limited or inconsistent scientific evidence).

Which patients should be treated?
Treatment is recommended for:

• women with a T-score of –2.5 or lower
• women who have had a low-trauma ­fracture
• women with a T-score between –1 and –2.5 and a 10-year FRAX hip-fracture risk of 3% or higher or a 10-year FRAX risk of major osteoporotic fracture of 20% or higher, or both. A major osteoporotic fracture involves the forearm, hip, or shoulder, or a clinical vertebral fracture (Level A evidence).
  

Only therapies approved by the US FDA should be used for medical treatment. They are raloxifene (Evista), bisphosphonates (Actonel, Boniva, Fosamax, Reclast), parathyroid hormone, denosumab (Prolia), and calcitonin (Fortical, Miacalcin) (Level A evidence).

Monitoring of therapy
In the absence of new risk factors, do not repeat DXA monitoring of therapy once BMD has been determined to be stable or improved (Level B evidence).

Lifestyle recommendations

• Counsel women about lifestyle factors that may affect BMD and fracture risk, which include smoking, poor nutrition and excessive weight loss, weight-bearing and muscle-strengthening exercise, and fall prevention (Level B evidence).
• Advise patients of current recommendations for calcium and vitamin D intake from the Institute of Medicine, which are calcium 1,200 mg/day and vitamin D 600 IU/day for women aged 51 to 70 years (Level B evidence).
• Counsel girls and women of all ages about the effects of lifestyle on bone health (Level C evidence – based on consensus and expert opinion).

WHAT THIS EVIDENCE MEANS FOR PRACTICE
By utilizing the FRAX risk-assessment tool, we can determine which patients truly require treatment. In the process, we should be able to reduce the overtreatment of younger women with low bone mass as well as the undertreatment of older women who appear to have less deranged bone mass.
ACOG also emphasizes the need to avoid the overutilization of DXA scans in various groups, as well as the importance of lifestyle adjustments to promote bone health in all age groups.

Related Article: STOP performing DXA scans in healthy, perimenopausal women Lisa Larkin, MD, and Andrew M. Kaunitz, MD (Stop/Start, Januaray 2013)

CLINICAL DENSITOMETRISTS WEIGH IN ON INDICATIONS FOR BMD ASSESSMENT

International Society for Clinical Densitometry (ISCD). Indications for bone mineral density (BMD) testing. http://www.iscd.org/official-positions/2013-iscd-official-positions-adult/. Updated August 15, 2013. Accessed November 7, 2013.

In its comprehensive review of BMD assessment, the ISCD elucidates the process, which typically involves DXA imaging.

Indications for BMD assessment

• The female patient is age 65 or older
• The postmenopausal patient is younger than age 65 but has a risk factor for low bone mass, such as low body weight, a history of fracture, use of a high-risk medication, or a disease or condition associated with bone loss
• The perimenopausal woman has clinical risk factors for fracture, such as low body weight, history of fracture, or use of a high-risk medication
• The adult sustains a fragility fracture
• The adult has a disease or condition associated with low bone mass or bone loss
• The adult is taking a medication associated with low bone mass or bone loss
• The patient is being considered for pharmacologic therapy
• The patient is being treated, to monitor effect
• The patient is not receiving therapy, but evidence of bone loss would lead to ­treatment.