Best prevention: Densitometry, drugs, determination

Baseline fractures in 7,705 postmenopausal women were assessed by semiquantitative spinal radiographs.

In women with severe prevalent vertebral fractures (more than 40% loss of vertebral body height), risk of additional vertebral fractures over 3 years was 38% and risk of new nonvertebral fracture (wrist, hip) was 14%.

Treatment of severe prevalent vertebral fractures with raloxifene 60 mg daily reduced the risk of new vertebral fractures by 26% and new nonvertebral fractures by 47% over 3 years.

To prevent 1 new nonvertebral fracture, 10 patients needed to be treated; to prevent 1 additional nonvertebral fracture, 18 patients needed to be treated.

Women who have already suffered a low-trauma fracture and women with osteoporosis have the greatest risk of fracture. The majority of women who suffer a low-trauma fracture have had neither a bone density measurement nor treatment with a bone medicine, many studies indicate. The Delmas study highlights the importance of prevalent vertebral fractures on the risk of subsequent fractures.

When to treat osteopenia. Many women with osteopenia should be on drug treatment, as should all women with osteoporosis, the NOF advises.

Although a woman with osteoporosis is more likely than a woman with osteopenia to suffer a fracture, the greatest absolute number of fractures occurs in osteopenic women, because that population is so large.

The NOF recommends starting treatment when the T–score measured by dual-energy X-ray absorptiometry (DXA) bone density testing is:

• less than –1.5 and the patient has 1 risk factor, or
  
• less than –2.0.²
  

What are the treatments for low bone mass?

Alendronate, risedronate, and raloxifene

The 3 most commonly used drugs for prevention and treatment of osteoporosis are: 2 bisphosphonates (alendronate and risedronate) and the selective estrogen receptor modulator raloxifene (TABLE 3). All prevent fractures and cost about the same. Alendronate and risedronate are taken by mouth once weekly; raloxifene, daily. A raspberry-flavored liquid alendronate was recently added, for the 10% of women who prefer not to take pills.

Patients must be careful to take alendronate and risedronate in the fasting state and with sufficient water to ensure the pill enters the stomach, then continue to fast another 30 minutes for maximal absorption. The patient needs to remain erect to reduce risk of reflux and esophageal irritation.

Teriparatide

Body JJ, Gaich GA, Scheele WH, et al. A randomized double-blind trial to compare the efficacy of teriparatide with alendronate in postmenopausal women with osteoporosis. J Clin Endocrinol Metab. 2002;87: 4528–4535.

Postmenopausal women with osteoporosis (n = 146) were randomized to receive either teriparatide injections (20 μg daily) plus placebo pills or alendronate 10 mg daily plus placebo injections for a median of 14 months. After 3 months of therapy, bone mineral density in the lumbar spine increased 12.2% and 5.6% in the teriparatide and alendronate groups, respectively. Teriparatide treatment resulted in fewer nonvertebral fractures than alendronate therapy.

Black DM, Greenspan SL, Ensrud KE, et al. The effects of parathyroid hormone and alendronate alone or in combination in postmenopausal osteoporosis. N Engl J Med. 2003;349:1207–1215.

Postmenopausal women with osteoporosis (n = 238) were randomized to receive daily parathyroid hormone (PTH) (full length 1 to 84) injections (100 μg daily), alendronate 10 mg daily, or the combination. After 1 year, lumbar spine bone density as assessed by DXA increased 6.3%, 6.1%, and 4.6% in the PTH alone, PTH plus alendronate and alendronatealone groups, respectively. In this study, PTH plus alendronate conferred no additional benefits over PTH alone.

Recombinant PTH 1-34 (teriparatide, Forteo) was approved in November 2002 for treatment of osteoporosis in postmenopausal women at high risk of fracture. It is very effective and likely superior to alendronate treatment. However, teriparatide, which is an injectable formulation, is expensive and this will likely limit its use to complex cases.

Interestingly, the combination of PTH plus alendronate does not appear to be additive in the treatment of osteoporosis. Given current data, the bisphosphonates should not be combined with PTH.

TABLE 3

Drugs for prevention and treatment of osteoporosis