Postmenopausal osteoporosis is a skeletal disorder in which bone strength and bone quality have decreased to a point where your bones are fragile and at high risk of fracture. Women are more likely to have osteoporotic fractures than men because their bones are smaller and they lose bone mass faster through hormonal changes around the time of menopause. The primary goals are to prevent fractures, maintain bone mass and bone strength, minimize or eliminate factors that contribute to falls, and treat those with osteoporosis or those who have low bone mass and additional risk factors for fracture.
There are three recommended ways to decide when to treat:
1. DXA. Dual-energy x-ray absorptiometry is the preferred technology for measuring bone density. This measures spine, hip, or total body BMD, providing reliability while exposing women to only 10 percent of the radiation in a chest x-ray. It can determine the presence and severity of osteoporosis and predict the risk of osteoporosis and fracture. All guidelines recommend start getting screened with DXA at age 65, or younger if they’re postmenopausal and have risk factors for fracture.
2. FRAX. This new Fracture Risk Assessment Tool calculates a woman’s 10-year probability of hip fracture and the 10-year probability of a major osteoporotic fracture (clinical spine, forearm, hip, or shoulder). It can include the results of a bone density scan or just risk factors such as family history of fracture or smoking history. Eventually, your FRAX score might be part of your DXA reading. If you’re over age 40, calculate your own risk of fracture by visiting the FRAX website. Simply select the “calculation tool” and your location, and follow the directions).
3. Identifiable Fracture. A person who already has an osteoporotic fracture is a candidate for treatment.
Prevent fractures by stopping or slowing bone loss and maintaining bone strength with the following lifestyle modifications:
- Intake an adequate amount of calcium and vitamin D daily (NAMS recommends 1,200 mg daily calcium for women age 50 and over; the Institute of Medicine recently updated their recommended daily allowance for vitamin D to 600 IU/d).
- Do weight-bearing exercise regularly.
- Try to prevent falls by minimizing or eliminating factors that contribute to them, such as walking in high heels or on slippery surfaces.
Prescription therapies may be recommended to reduce fracture risk in women with very high risk for osteoporosis and fracture. A number of government-approved options are available. The most commonly used therapies in the United States are listed below. To ensure these drugs are most effective, adequate intake of calcium and vitamin D are essential. Also, remember that when these drugs are stopped, bone loss can resume; therapy does not permanently “cure” osteoporosis.
Bisphosphonates. This class of bone-specific drugs decreases the activity of bone-dissolving cells (osteoclasts) and has been found to reduce the risk of spine and nonspine fractures. Alendronate, risedronate, ibandronate, zoledronic acid, and etidronate are examples of these drugs, which are available in various doses (daily, intermittent, yearly) and regimens (oral, IV).
Estrogen agonists/antagonists. These modulators act like estrogen in some parts of the body and have an antiestrogen effect in others. Raloxifene (Evista) is government approved for prevention and treatment of osteoporosis.
Denosumab. This monoclonal antibody inhibits bone loss. It has been shown to increase bone mineral density in postmenopausal women, as well as to reduce incidence of fracture in women with osteoporosis.