Some 200 million people worldwide, including approximately 25 million Americans, suffer from osteoporosis-a "thinning of the bones." Often progressing without pain or other symptoms, osteoporosis leads to loss of height, spinal deformities, bone fragility, and a consequent increased risk for fractures.
In the United States alone, more than 1.5 million fractures each year are attributed to osteoporosis. Approximately one-third of all American women will have an osteoporosis-related spinal fracture by age 65. By extreme old age, some one-third of women and one-sixth of men will suffer the most serious complication, a hip fracture.
Bone Density Measurement
Osteoporosis is easier to prevent than to treat. In general, once bone loss has occurred, it cannot be replaced. And while decreases in bone density are often associated with fractures, not all individuals with reduced bone density will develop fractures.
Today, the most definite way to learn whether you are suffering a serious reduction in bone density associated with osteoporosis is by a bone density measurement.
Physicians at the Skeletal Health and Osteoporosis Center at BWH perform bone density measurements using the most advanced technology of dual x-ray absorptiometry (DXA). DXA makes it possible to quantify bone density at the relevant fracture sites of the spine, proximal femur, and forearm, as well as within the total body, with remarkable accuracy and reproducibility - and with the highest standards of quality control.
This non-invasive diagnostic procedure requires that the patient lie down (for spine and proximal femur) for only 2.5 minutes, or sit comfortably (for forearm) for 5 minutes. During this time, a scanning arm moves over the designated site. Radiation exposure from DXA is very low - approximately 3 to 6 mrems, or less than background radiation including that from radon.
Physicians in the Osteoporosis Center at BWH can also measure the bone density of the central portion of the lateral spine, even if the site is affected by the presence of osteoarthiritic skeletal changes - changes that might falsely raise conventional spinal bone density measurements.
To assess bone density loss, physicians compare the mean bone density measurements in young adults with the mean measurements in control subjects of the same age and gender. The World Health Organization considers a bone density value of more than 2.5 standard deviations below peak bone mass as the criteria for diagnosing osteoporosis. Established osteoporosis also includes the presence of a fracture.
These bone density measurements are standardized in two ways:
Z Scores: Because bone mass declines with age, this measurement compares the bone mass in a particular patient with those values of age and gender-matched individuals. A Z score of -1, or one standard deviation decrease in bone density compared with age-adjusted controls, is associated with a doubling of risk for fracture.
T Scores: With this measurement, bone density for a given individual is compared with the values for young, normal, control patients to determine whether there is a reduction in bone mineral density from peak bone mass.
Who should be tested?
Routine use of bone densitometry to screen all normal, premenopausal women is not recommended. It is, however, indicated for:
- Estrogen deficient women, to identify those women who might benefit from therapy to protect the skeleton from osteoporosis.
- Patients with evidence of vertebral abnormalities, non-traumatic fractures, or reduced bone mass on x-ray films.
- Patients receiving long-term glucocorticoid therapy.
- Patients with primary or secondary hyperparathyroidism, to identify those who would benefit from treatment.
- Monitoring the clinical response to a treatment intervention to determine whether the prescribed treatment is effective or whether an alternative therapy should be used.
Reimbursement
BWH's Skeletal Health and Osteoporosis Center provides healthcare services for numerous insurers. For patients at risk for osteoporosis, DXA bone density measurement is covered by Medicare and most private insurers and HMOs in Massachusetts.
Please note: Even when these services are covered by your insurer, a referral from a primary-care physician may be required for reimbursement.
The Advantages of Brigham and Women's Hospital
BWH's Skeletal Health and Osteoporosis Center is a leading program for diagnostics and research on osteoporosis, with highly advanced equipment for bone density evaluation (Hologic).
Here, physicians and research staff conduct research studies sponsored by the National Institute of Health, and are investigating new pharmaceutical therapies both to prevent bone loss in recently menopausal women and to treat patients already suffering from osteoporosis. These research efforts provide the program's patients with the most up-to-date information on promising new alternatives for treatment.
For more information or to schedule an appointment, please call 617-732-5666.
Back to: Osteoporosis Care
