OSTEOPOROSIS – DIAGNOSIS AND MANAGEMENT

Hope Druckman, MD
Overlake Medical Center (Bellevue, WA)

Osteoporosis is a common and silent disease primarily affecting women, particularly in the postmenopausal years. This is a costly problem of enormous public health proportions. It is important to focus on screening and treatment of this condition, so that we can prevent serious fractures. Hip fractures in the elderly can be particularly debilitating, resulting in loss of independence, nursing home placement, and in some situations can lead to death because of complications such as blood clots to the lungs. Fortunately, accurate, cost effective, and safe testing is now available to diagnose osteoporosis.

The definition of osteoporosis is based on measurements of bone density, or the strength of the skeleton. By using a machine called a DEXA scan, it is possible to look at an individual’s bone density and compare it to those who are of the same age and gender. This is called the Z score. Comparison is also made to young adults of the same gender and is termed the T score. A BMD or bone mineral density between -1 and -2.5 standard deviations below the young adult mean bone density is defined as osteopenia, or low bone mass. A BMD which is less than- 2.5 is the definition of osteoporosis. As BMD decreases, the relative risk of developing fracture increases. Bone density is measured in both the spine as well as the hip. In people with significant degenerative arthritis, particularly in the spine, this can falsely elevate the score and not give a true picture of an individual’s bone density.

There are a number of factors associated with fracture risk. Many fractures occur in women who do not have osteoporosis, but osteopenia, because there are so many more patients who fall into this category. Factors which have been shown to affect fracture risk and are independent of BMD include advanced age, previous fracture, low body weigh less than 127 pounds, cigarette smoking, excessive alcohol intake, chronic treatment with steroids and also family history of hip fracture. The most significant of these risk factors are increasing age and previous fracture.

In the United States, many experts are recommending bone density screening in postmenopausal women 65 and older. Screening recommendations for women under the age of 65 are not as clear, and are based on risk factor assessment. Individuals should be counseled about reducing risk factors, most importantly smoking cessation. They should also be encouraged to limit alcohol intake and participate in regular exercise with a focus both on weight-bearing as well as muscle strengthening. Any weight-bearing exercise regimen, including walking is helpful. Exercises which help with balance are important because this can help to prevent falls. It is also important to assess the home for any potential fall risks, such as loose throw rugs and clutter on the floor. All adults should be consuming at least 1200 mg. of calcium per day as well as 400 to 800 units of Vitamin D per day. For those women without risk factors for accelerated bone loss, follow up DEXA scans should be performed every three to five years. In women who have just gone through the menopause, since the most pronounced bone loss occurs during the first five years, screening DEXA scans might be recommended more frequently, depending upon other risk factors.

According to the National Osteoporosis Foundation, pharmacologic therapy is recommended for postmenopausal women with T-scores less than -2.0, regardless of risk factors for fracture, and with T-scores less than -1.5 if risk factors are present. The most commonly used medications are called bisphosphonates. These medications stimulate growth of new bone. Newer preparations of this category of drug can be administered either once a week or once a month. Patients need to take this medication on an empty stomach with a large glass of water, and must remain upright for an hour, in order to prevent the relatively unlikely problem of the pill being lodged against the wall of the esophagus and causing esophagitis.

Another category of medication used for the treatment of osteoporosis is the selective estrogen receptor modulator (SERM). Raloxifene has been shown to increase bone mineral density and reduces the risk of vertebral fractures. This drug also appears to lower the risk of breast cancer. Tamoxifen, which is another SERM that is used for the prevention and management of breast cancer, is not specifically prescribed for treatment of osteoporosis, but has been shown to protect bones.

Estrogen and progesterone therapy had been previously used as a first-line treatment for osteoporosis, but since the Women’s Health Initiative Study showed a small but real increase in the risk of breast cancer, stroke, thrombophlebitis, or blood clots, and heart disease, this is no longer the case. Hormone replacement therapy (HRT) is still used in women with menopausal symptoms and for women with an indication for treatment with the bisphosphonates who are unable to tolerate this category of medication.

Calcitonin, which is a hormone that stimulates bone growth, is a less effective treatment for osteoporosis, but is sometimes prescribed. It is administered nasally, with one spray per day, alternating nostrils. Calcitonin can also be used in an injectable form in the setting of an acute compression fracture of the spine, helping to ease pain in the healing of the fracture.

There is currently no consensus on the optimal approach to monitoring therapy for osteoporosis. Up to one-sixth of women on bisphosphonate or hormone therapy continue to lose bone. Most experts are recommending rechecking the bone density within one to two years of starting therapy to document either improvement or stability of the bones, with less frequent monitoring subsequently.

Individuals who sustain a fracture secondary to osteoporosis and are not on osteoporosis medication should be started long term pharmacologic therapy. In the United States and Europe, the majority of patients who sustain such fractures are not started on medication despite convincing data demonstrating their benefit in reducing the risk of developing a second fracture. Men are less likely than women to be evaluated or treated for osteoporosis after having such a fracture. As men age, they are at risk for development of osteoporosis, although less so than women. Clinicians as well as patients need to be educated about the importance ofosteoporosis treatment after any osteoporotic fracture.

In summary, osteoporosis is a significant public health problem. Prevention of this disease starts at a young age, with adequate calcium and Vitamin D intake. Smoking cessation, modest alcohol intake, as well as regular exercise all contribute to bone health. Women should be screened for osteoporosis after their menopause, with those who are in a high risk category being screened earlier and more frequently. Those individuals who show substantial bone loss with a T-score of less than -2.0 should begin pharmacologic therapy, preferably a bisphosphonate if tolerated. Our goal is prevention of fractures which not only improves quality of life but also will save billions of dollars in health care costs.

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