Osteoporosis Detection

Health |

We know osteoporosis is a horrible disease that often affects post-menopausal women. We know that the decreased estrogenic environment present after the menopause is associated with increased incidence of osteoporosis and osteopenia, the low bone mass precursor to osteoporosis. Because the ramifications of fractures resulting from osteoporosis are so serious (potential for death, decreased mobility and healthcare dollars), it is important to make a diagnosis of osteoporosis or osteopenia as soon as possible. Osteoporosis is treatable and even preventable.

There are two types of bone in the body: trabecular and cortical. Osteoporosis is especially associated with loss of trabecular bone. The most rapid decrease in trabecular bone density occurs in the first five to eight years after menopause onset. This is called type 1 osteoporosis or osteoporosis resulting from decreased estrogen. However, decreased estrogen is not the only risk factor for post-menopausal osteoporosis.

If you know you are at increased risk for low bone mass, you may be more likely to get early detection and treatment. If you have any of the following other risk factors for osteoporosis, please discuss your risk and possible management with your healthcare provider.

Risk Factors for Osteoporosis
Genetic factors:
family history of osteoporosis
Caucasian/Asian race
Menstrual status:
history of lack of menses (may be due to eating disorder, high prolactin, or excessive exercise
Environmental factors:
cigarette smoking
more than three to four alcoholic drinks per day
prolonged immobilization or sedentary lifestyle
decreased exposure to sunlight without vitamin D supplementation
excessive use of caffeine
Disease states:
multiple myeloma
Cushing’s syndrome
thyroid disease
primary hyperparathyroidism
rheumatoid arthritis
chronic obstructive pulmonary disease
eating disorders (anorexia and bulimia)
chronic liver or kidney disease
malabsorption syndromes
corticosteroids (greater than or equal to 7.5 mg per day for more than six months)
anticoagulant agents (Coumadin and heparin)
some anticonvulsants (eg. phenytoin)
immunosuppressive drugs (eg, cyclosporine)
some thyroid medications (eg. levothyroxine)
Are there any physical signs of osteoporosis?
When a woman is in her 50s, the vertebrae of the spine are often the first sites to be affected by osteoporosis. Wedge-type fractures may occur and cause the “dowager’s hump” with loss of height and possibly back and leg pain. Later on, in her 70s to 80s, the hip and wrist are common sites for fractures for a woman.

Are all measurements of bone density equivalent?
No. Currently the preferred technique to measure bone density is called the dual-energy X-ray absorptiometry (DXA) of both the hip and spine. This gives an assessment of bone loss at the sites of the body most susceptible to osteoporotic fractures. While other bone density measures are available, they do not alone adequately assess bone status. For example, measurement of heel bone density does not assess spinal (vertebral) bone status as well as it does hip bone status. Since vertebral bone is often affected before hip bone, a wnl heel bone (calcaneus) assessment does not guarantee a wnl vertebral bone status.

How often should DXA be repeated?

If a patient has low bone mass (osteopenia/osteoporosis), then yearly DXA scans may be appropriate. If a postmenopausal woman not on medication has a WNL DXA, then repeat tests may be considered about every two years.

Does a DXA test hurt?
No. You lie still on a non-enclosed table, and an overhead machine will scan over your body.

What about urine tests for bone status?
Urinary tests for bone turnover are sometimes used as a method to assess bone loss more frequently than yearly DXA in order to monitor response to therapy and bone loss.