Osteoporosis

Basic Information

Osteoporosis is a metabolic bone disease in which a progressive decrease in bone mass occurs. The bones become more brittle and fragile, skeletal weakness occurs, and as a result there is a higher risk for fractures.

Osteoporosis currently affects nearly 25 million women and men in the U.S. but is almost four times more likely to affect women than men. In fact, the postmenopausal white or Caucasian woman (51 to 70 years of age) is at greatest risk for the disease.

This is a serious condition that can result in institutionalization or even death. There are approximately 275,000 hip fractures in the U.S. per year. Eighty percent of hip fractures are caused by osteoporosis and in those cases 17 percent result in death within three months. That is why it is important if you feel you are at risk or have a predisposition for this disease to discuss risk factor reduction or prevention methods with your health care provider.

Who is at greatest risk for osteoporosis and what are the most common risk factors associated with it?

• age -- after 40 years, each decade is associated with a fivefold increase risk
• small-framed or small-boned Caucasian women, especially if there is a history of the disease in the family -- this is considered the greatest risk group
• Asian women are also considered at risk
• decreased estrogen levels in postmenopausal women
• early menopause
• tobacco use
• alcohol use
• poor nutrition
• vitamin and mineral deficiency, especially calcium and Vitamin D
• sedentary lifestyle
• family history
• hyperthyroidism
• Cushing's Syndrome
• use of oral steroids (for asthma or arthritis)

Symptoms

Most patients have no signs or symptoms but 25 percent of white women over 60 years display spinal compression fracture. Sometimes symptoms may include:

• aching pains in the bones, most usually in the back
• curvature of the spine
• loss of height
• pain from a fracture, most commonly of the hip, spin or wrist

Diagnosis/Treatment

In a primary care setting, your health care provider will look for signs of the progressive development of dowager's hump (dorsal kyphosis), take a history and physical examination, evaluating identified risk factors and possible secondary causes. The causes of secondary osteoporosis are either endocrine, drug-induced or miscellaneous (i.e. rheumatoid arthritis, chronic obstructive lung disease, chronic renal failure, etc.) and make up less than 5 percent of all cases. Additionally you will be assessed for loss of height and any skeletal pain that may be indicative of fractures.

Conclusive diagnosis is made by BMD (bone mineral density) determination consisting of seven separate tests which include:

• DEXA (dual-energy X-ray absorptiometry) -- This is a sensitive measure of bone density and can be used to keep track of bone density as time progresses. Usually osteoporosis must be advanced to be detectable on an X-ray. BMD should be performed on all women with determined risk factors.

During diagnosis it is ideal to determine who is at greatest risk for fractures. To make that determination it is important to understand the definition of osteoporosis: a bone density of 2.5 standard deviations below the peak mean bone density of the general population. Those at the greatest risk for fractures are those who have bone densities below this level. Risk in the postmenopausal woman depends on bone mass achieved at maturity as well as subsequent rate of bone loss.

Your blood should be measured for vitamin D levels, especially if you reside in a climate in which you have low sun exposure.

Preventive therapy has proven to be effective in minimizing risks. What you can do to minimize risk factors include:

• stopping smoking
• lowering alcohol and caffeine intake
• being certain you have adequate nutrition including enough calcium and vitamin D
• increase exercise, especially walking (i.e. weight-bearing exercise), if approved by your health care provider

The need for calcium in women as they age cannot be underestimated. Dietary calcium supplement should be between one thousand to fifteen hundred mg per day. It is believed that the average woman's intake of calcium from her diet rarely exceeds 500 mg, so a daily supplement of 500 mg is the minimum requirement. Ask your health care provider if this is enough -- if you are not on estrogen therapy or if you smoke, the minimum supplement recommended may be doubled to 1,000 mg.

Vitamin D helps absorb calcium from the diet so 400--800 IU's (or international units) is usually needed.

Estrogen therapy for postmenopausal women is usually very helpful. It has been shown to reduce the incidence of arm and hip fractures by 50 to 60 percent. With calcium supplement the figure could rise to 80 percent. Before going ahead with estrogen replacement therapy be sure you discuss both benefits and risks with your health care provider. Benefits are thought to include a marked decrease in coronary artery disease but may slightly increase the risk for breast or uterine cancer. Women who have not had a hysterectomy are usually advised to take estrogen in combinaiton with progestin in order to reduce the risk for endometrial cancer.

Osteoporosis is a lifelong disorder and estrogen therapy must be continued indefinitely because once it is stopped there is a quick resumption of bone loss. A plan must be initiated between you and your health care provider for long-term behavior modification (diet, nutrition) as well as appropriate pharmacological therapy which takes into account any side effects that may develop. For instance Alendronate, an oral bisphosphonate, has been approved for prevention of osteoporosis but may cause ulcers in some patients. A new product called Raloxifene has recently been approved by the FDA which shows similar benefits to estrogen replacement therapy. But it too may produce side effects in certain patients. Calcitonin, either taken by injection or as a nasal spray, is often recommended for postmenopausal women of at least five years who are not able to take estrogen.

If you feel you have symptoms of osteoporosis or would like an assessment or information about prevention, please see your health care provider.